,transcriber ,note ,since #acd appeared on page #adc and again on page #adg1 the ,section number on pages #adg and all succeeding were incremented4 ,the ,table of ,contents was also incremented respectively4 ,text emphasis denoted by ,italics4 ,list of ,,errata below has been applied to the text4 ,,errata4 ,page #dd4 line #d4 from the bottom1 for that read as #ahi4 #f4 for appearenes read appearances #dfd4 #d4 for ,d',,aubenton read ,,daubenton #dhb4 #ab4 for adversaries read adversary ,,illustrations ,,of ,,the ,,huttonian ,,theory ,,of ,,the ,,earth ,,by ,,john ,,playfair ,f4 ,r4 ,s4 ,,edin4 ,,and ,,professor ,,of ,,mathematics ,,in ,,the ,,university ,,of ,,edinburgh4 ,nunc naturalem causam qurimus et assiduam1 non raram et foriuitam4 ,,seneca4 ,,edinburgh3 ,,printed ,,for ,,cadell ,,and ,,davies1 ,,london1 ,,and ,,william ,,creech1 ,,edinburgh4 #ahjb4 ,entered in ,stationers ,hall4 ,,neill ,,co4 ,printers1 ,edinburgh ,,advertisement4 ,,the ,treatise here offered to the ,public1 was drawn up with a view of explaining ,dr ,hutton's ,theory of the ,earth in a manner more popular and perspicuous than is done in his own writings4 ,the obscurity of these has been often complained of2 and thence1 no doubt1 it has arisen1 that so little attention has been paid to the ingenious and original speculations which they contain4 ,,the simplest way of accomplishing the object proposed1 seemed to be1 to present a ,general ,outline of the ,system1 in one continued ,discourse2 and to introduce afterwards1 in the form of ,notes1 what farther elucidation any particular subject was thought to demand4 ,through the whole1 ,i have aimed at little more than a clear exposition of facts1 and a plain deduction of the conclusions grounded on them2 nor shall ,i claim any merit to myself1 if1 in the order which ,i have found it necessary to adopt1 some arguments may have taken a new form1 and some additions may have been made to a system naturally rich in the number and variety of its illustrations4 ,,of the qualifications which this undertaking requires1 there is one that ,i may safely suppose my self to possess4 ,having been instructed by ,di ,hutton himself in his theory of the earth2 having lived in intimate friendship with that excellent man for several years1 and almost in the daily habit of discussing the questions here treated of2 ,i have had the best opportunity of understanding his views1 and becoming acquainted with his peculiarities1 whether of expression or of thought4 ,in the other qualifications necessary for the illustration o a system so extensive and various1 ,i am abundantly sensible of my deficiency1 and shall therefore with great deference1 and considerable anxiety wait that decision from which there is no appeal4 ,,edinburgh ,,college1 #ast ,march #ahjb4 ,,table ,,of ,,contents4 ,,introduction4 ,object of a ,theory of the ,earth4 ,division of minerals into ,stratified and ,unstratified4 ,page #a ,,section ,i4 ,,phenomena ,,peculiar ,,to ,,stratified ,,bodies4 #a4 ,materials of the ,strata4 ,page #d ,present strata composed of the remains of more ancient rocks1 #a4 ,proofs from calcareous strata1 #b4--;from siliceous1 #c4--;from argillaceous1 #d4--;from bituminous1 #e1 #f4 ,absence of organized remains from the strata called primitive1 not universally true1 #h1 #i4--,term ,primary substituted for ,primitive4 ,composition from the materials of more ancient rocks1 #aj4 #b4 ,consolidation of the ,strata4 p4 #ae ,consolidation1 what1 #aa4 ,objections to aqueous consolidation1 #ab1 #ac1 #ad4 ,compression affects the action of fire on bodies1 #ae1 #af1 #ag4--;,igneous consolidation of minerals prove from fossil wood1 #ai4--;,from the flints in chalk1 #bj4--;from sandstone1 #ba4--;from the calcareous strata1 #bc1 #bd1 #be4--;from the argillaceous1 #bf1 #bg4--;from the bituminous1 #bh1 #bi4--;from the saline1 #cb4 ,salt mines in ,cheshire4 ,trona of ,africa1 #ed1 #ce4 #c4 ,position of the ,strata4 p4 #dj ,strata formed at the bottom of the sea1 #cf4 ,apparent elevation not produced by the retreat of the sea1 #cg4--,strata1 horizontal1 when formed1 #ch1 #ci4 ,disturbance of the strata proved from their inclined position #dj1 #da1 #db4--;from shifts1 c4 #db4 ,shifts of different dates1 ib4 ,disturbance of the primitive strata visible at their junction with the secondary1 #dc1 #dd4 ,this disturbance produced by a force directed upward1 #de1 #df4 ,this force the effect of subterraneous heat1 #dg1 #dh4 ,,section ,,ii4 ,,phenomena ,,peculiar ,,to ,,unstratified ,,bodies4 #a4 ,metallic ,veins4 p4 #eg ,veins defined4 ,they contain substances that were once in fusion1 #di1 #ej4 ,metallic veins1 native metals1 c4 #ea4 ,native copper1 #eb4 ,manganese1 #ec4 ,fragments of rocks included in veins1 #ee4 ,shifting and heaving of veins1 #ef1 #eg4 ,veins of different dates1 #eh4 ,stratification not found in veins4 ,coating of the sides1 what1 #ei4 ,metallic veins most common in primitive strata2 but not confined to them1 #fj4 #b4 ,whinstone4 p4 #ff ,enumeration of stones of this genus1 #fa4 ,whin1 whether in veins or in masses1 resembles lava1 #fb4 ,is a subterraneous lava1 #fc4 ,columnar structure an argument for fusion1 #fd4 ,not produced by drying1 #fe4 ,whinstone penetrated by pyrites1 #ff4 ,induration of the strata in contact with whin1 #fg ,coal charred by whinstone veins1 #fh4 ,disturbance of the strata by whinstone veins1 #fi4 ,phenomena of whin interposed between strata1 #gj1 #ga4 ,transition from whin to strata not gradual4 #gb4 ,agates and chalcedonies in whinstone1 #gd4 ,this stone melted and reproduced from fusion by ,sir ,james ,hall1 #ge4 ,mineral alkali found in it by ,dr ,kennedy1 ib4 ,whinstones of different formation1 #gf4 ,porphyry a species or variety of whinstone1 #gg4 #c4 ,granite4 p4 #hb ,granite defined4 ,exists in masses and veins1 #gg4 ,the basis of other rocks1 #gh4 ,its original fluidity inferred from the crystallization of its parts1 #gi4 ,its fusion1 from the structure of the ,portsoy granite1 #hj1 #ha4--;from granite veins1 #hb4 ,general conclusion as to the igneous origin of minerals1 #hc1 #hd1 #he4 ,actual existence of subterraneous heat known from hot springs1 volcanoes1 earthquakes1 #hf4 ,volcanic fire seated deep under the surface1 #hg4 ,subterraneous heat not accompanied by burning1 #hh1 #hi4 ,transmission of subterraneous heat1 so as to produce hot springs1 c4 #ij1 #ia4 ,,section ,,iii ,,phenomena ,,common ,,to ,,stratified ,,and ,,unstratified ,,bodies4 p4 #ig ,chemical agents which produce the decomposition of mineral substances at the surface1 #ib1 #ic4 ,mechanical agents1 #ie1 #if4 ,proofs of wearing from the sea shore1 #ig1 #ih4 ,rivers1 #ii1 #ajj4 ,defiles among mountains1 #ajb4 ,supply of the soil from the decomposition of rocks1 #ajc4 ,gravel in the soil1 #ajd1 #aje4 ,gold found in the soil1 #ajf4 ,tin1 #ajg4 ,proofs of waste from mountainous countries1 #ajh1 #aji4 ,structure of ,valleys1 #aaa4 ,transportation of stones1 #aab4 ,nearest measure of the waste1 #aac4 ,general remarks1 #aad1 #aae4 ,no production of minerals on the surface1 #aaf4 ,reproduction at the bottom of the sea1 #aag4 ,continued system of decay and renovation1 #aah4 ,defence against the charge of impiety1 #aai4 ,antiquity and order of the revolutions of the globe1 #abj1 #aba1 #abb1 #abc1 #abd4 ,consistency with the ,sacred ,writings1 #abe4 ,scope of this theory of the earth distinguishes it from others2 beauty and extent of its views1 #abf4 ,new facts1 #abg4 ,comparison of this theory with that of ,buffon1 #abi4 ,of ,lazzaro ,moro1 #acj4 ,plutonic system1 #aca4 ,distinguished by the principle of compression1 #acb4 ,explains the oblate figure of the earth1 ib4 ,prejudices against this system1 #acc4 ,what may be expected from the progress of science1 #acd4 ,,notes ,,and ,,additions4 ,,note ,i4--,origin of ,calcareous ,earth4 p4 #adc ,dr ,hutton's opinion on this subject accurately stated1 #ace4 ,misrepresented by ,kirwan1 #acf4 ,,note ,,ii4--,origin of ,coal4 p4 #adg ,vegetable origin of coal4 ,opinion of ,buffon1 #acg4--of ,arduino1 ib4--of ,lehman1 #ach4 ,distinction attempted between wood coal and mineral coal1 #aci4 ,not of different origin1 but gradually pass one into the other1 #adj4 ,bovey coal1 #ada4 ,kirwan derives the matter of mineral coal from the decomposition of hornblende1 c4 #adc4 ,absurdity of this supposition1 #add1 #ade1 #adf1 #adg4 ,,note ,,iii4--,primitive ,mountains4 p4 #afj ,lehman introduced the term ,primitive mountains1 #adi4 ,supposed more ancient than organized bodies1 #aej4 ,stratification of primitive mountains denied by ,pini1 and maintained by ,saussure1 #aea4 ,,note ,,iv4--,primary ,strata not ,primitive4 p4 #afc ,shells found in primary strata1 #aeb4 ,sandstone in primary mountains1 #aec4 ,quartzy sand in the schistus of the ,grampians1 ib4 ,rocks distinguished by ,werner into three orders1 #aed4 ,objections to this arrangement1 #aee4 ,,note ,v4--,transportation of the ,materials of the ,strata4 p4 #aga ,the transportation of materials1 objected to by the ,neptunists1 is implied in their own system1 #aef1 #aeg1 #aeh4 ,proofs of great transportation from the animal and vegetable remains1 found in rocks1 #afj4 ,,note ,,vi4--,kirwan's ,notion of ,precipitation4 p4 #ahj ,difficulty1 of precipitating the materials dissolved in the chaotic fluid1 #afb4 ,insufficiency of the explanation attempted1 ib4 ,,note ,,vii4--,compression in the ,mineral ,regions4 p4 #aha ,effects ascribed to compression by ,newton1 compared will the effects ascribed to it in this theory1 #afc4 ,fallacy of ,kirwan's argument concerning the fusion of ,carrara marble1 #afe1 #aff4 ,heat of the mineral region may be supported without fuel1 #afg4 ,quotation from ,newton's ,optics1 ib4 ,general remarks1 #afi4 ,,note ,,viii4--,sparry ,structure of ,calcareous ,petrifactions4 p4 #aij ,sparry and organic structure co-exist in certain fossils1 #aga4 ,sparry and stratified structure co-exist in gneiss1 marble1 c4 #agb4 ,,note ,,ix4--,petroleum1 c4 p4 #aid ,petroleum1 c4 from the distillation of coal1 #agc4 ,gradation from petroleum to coal often met with1 #agd4 ,connection of amber and coal1 #age4 ,why mines of blind coal have not always petroleum mines near them1 #agf4 ,,note ,x4--,the ,height above the ,level of the ,sea1 at which ,marks of ,aqueous ,deposition are now found4 p4 #aii ,these marks consist either in stratification or in marine objects1 #agg4 ,the marks of stratification observed1 #adgci feet above the sea1 #agh4 ,shells in ,peru1 #adaij1 #agi4 ,kirwan's mistake concerning these shells1 #ahj4 ,his error similar to ,,voltaire',s1 #aha4 ,,note ,,xi4--,fracture and ,dislocation of the ,strata4 p4 #bjd ,slips1 #ahb4 ,rib of limestone in a slip near ,huddersfield1 #ahc1 #ahd4 ,singular fracture of pudding-stones at ,oban in ,argyleshire1 #ahe4 ,similar phenomena observed by ,saussure between ,nice and ,genoa1 ib4 ,remarks on it1 #ahf4 ,,note ,,xii4--,elevation and ,inflection of the ,strata4 p4 #bji ,junction of primary and secondary strata1 #ahg4 ,breccia incumbent on the primary1 #ahh4 ,junction of the primary and secondary strata3 ,at ,torbay in ,devonshire1 #aij1--;coast of ,berwickshire1 #aia1--;,cullen in ,banffshire1 #aic1--;,ardencaple in ,dunbartonshire1 ,arran1 c4 #aid1--,pembrokeshire1 #aie1--;,jedburgh1 #aif1--;,ingleborough in ,yorkshire1 #aig1--;,cumberland1 #aih4 ,inflection of the strata1 #aii4 ,remarkable instances in the ,alps and ,pyrenees1 #bjj1 #bja1--on ,ben-,lawers in ,perthshire1 #bjb1--;coast of ,berwickshire1 ib4--,plymouth1 #bjc4 ,strata suffering such inflections have been soft and ductile1 #bjd4 ,general property of these inflections1 #bje1 #bjf4 uniform stretch of the primary strata1 #bjg4 ,inferences as to the nature of the elevating force1 #bjh4 ,imperfection of other theories4 ,crystallisation1 ib4 ,marks of undul in the schistus1 #bji4 ,elevation of the strata a stronghold of the ,huttonian theory1 #baj4 ,elevation of the strata enables us to see far into the interior of the earth1 #baa4 ,,note ,,xiii4--,metallic ,veins4 p4 #bci ,specimens of native iron1 #bab1 #bac4 ,margraaf's specimen1 #bad4 ,kirwan's hypothesis1 #bae4 ,increase of the specific gravity of native gold by fusion1 no argument against its igneous origin1 #baf4 ,specimens of gold and silver shooting through quartz1 an argument in favour of the ,huttonian theory1 #bah1 #bai4 ,proof in favour of the same from chalcedony including calcareous spar1 #bbj4 ,matter that fills veins not from above or from either side1 #bba4 ,opinion of the ,neptunists1 #bbb4 ,supposed fact that veins are less rich as the depth increases1 #bbc4 ,no marks of horizontal deposition in veins2 their coating differs from stratification1 #bbd4 ,neptunists appear to be misled by the term ,stratification1 #bbe1 #bbf4 ,veins heave or shift one another1 #bbg4 ,vast force employed for that purpose1 #bbh4 ,veins of different formation1 #bca4 ,pieces of rock insulated in veins1 #bcb4 ,supposition that veins have been filled by infiltrations1 absurd1 #bcc4 ,lenticular veins1 and ,pipe veins1 #bcd4 ,,note ,,xiv4--,on ,whinstone4 p4 #bfj ,whinstone1 neither of volcanic nor aqueous formation1 #bce4 ,zeolite and carbonate of lime included in whinstone1 but not in lava1 ib4 ,not introduced by infiltration1 #bcf4 ,disposition of whinstone mountains differs from that of streams of lava1 #bcg4 ,this argument first employed by ,mr ,strange1 #bch4 ,his general views of this subject1 #bci4 ,explanation of the regular structure of whinstone hills1 according to ,dr ,hutton's theory1 #bdj4 ,many hills supposed to be extinguished volcanoes1 are rocks of real whinstone that has flowed deep under the surface4 ,vein of whinstone mistaken for a stream of lava by ,faujas1 #bda1 #bdb4 ,submarine volcanoes of ,dolomieu1 #bdc4 ,objections to this theory1 #bdd1 #bde4 ,dolomieu in another place contends for the aqueous formation of basaltes1 #bdf4 ,his arguments answered2 also those of ,bergman1 #bdh1 #bdi4 ,argument of ,,werner for the aqueous origin of basaltes1 #bej4 ,remarks on the supposed gradual transition of basaltes to argillaceous schistus1 #bea1 #beb4 ,of the shells said to be found in basaltes1 #bec4 ,instances from ,portrush in ,ireland1 and from ,cerigo on the ,coast of ,greece1 ib4 and #bed1--;from the ,veronese1 #bee4 ,objections to the ,neptunian formation of whinstone1 founded on the difference between it and the contiguous stratified rocks1 #bef4 ,on the resemblance of the strata below and above certain masses of whinstone1 #beg4 ,on the irregularity of the thickness of those masses1 #beh4 ,wedge form masses of whinstone included between strata1 #bei4 ,consequences of this wedge form1 #bfj4 ,sandstone fragments included in whin1 #bfa1 #bfb4 ,bending of the strata contiguous to whinstone1 #bfd4 ,induration1 #bfe1 #bff4 ,charring of coal by whin1 #bfg4 ,of the manner in which the bitumen may have been driven off by heat1 #bfh4 ,two kinds of fossil coke1 #bfi4 ,graduation into plumbago1 ib4 and #bgj4 ,only remaining objection obviated by ,sir ,james ,hall's experiments1 #bga4 ,,note ,,xv4--,on ,granite4 p4 #cjg ,granite veins of two kinds1 #bgd4 ,veins ,of which the communication with large masses of the same stone is not visible3 ,at the ,isle of ,coll in the ,hebrides1 #bge1--;at ,portsoy1 #bgf1--;in ,cornwall1 #bgg1--;in ,glentilt1 #bgh4 ,veins visibly connected with larger masses4 ,argument furnished by them in favour of this theory1 #bgi1 #bhj4 ,impossibility of their being formed by infiltration1 #bha4 ,veins of this kind in ,arran1 #bhb1--;,galloway1 #bhc1--sides of ,loch ,chloney1 ,invernessshire1 #bhd1--,st ,michael's ,mount1 ,cornwall #bhe4 ,fragments of schistus contained in granite1 #bhg4 #b4 ,granite of ,portsoy4 p4 #cbj ,description of this granite1 #bhh4 ,pierre graphique of ,m4 ,patrin not perfectly the same with that of ,portsoy1 #bhi4 ,quartz crystallized in the pierre graphique1 #bij4 ,instances of quartz crystallized in other granites4 ,in that of ,st ,agnes in ,cornwall1 #bia4 ,whether this crystallization is only found in secondary granites1 #bib4 #c4 ,stratification of ,granite4 p4 #cbf ,question stated concerning the stratification of granite1 #bic4 ,remarkable examples of stratified granite at ,chorley ,forest1 ,leicestershire1 and at ,fassnet ,water in ,berwickshire1 #bie4 ,stratification of ,mont ,blanc1 and the ,aiguilles of ,chamouni maintained by ,saussure1 #bif1 #big4 ,seems nevertheless doubtful1 #bih4 ,in the granite mountains of ,arran doubtful2 #cjj4 ,explanation of the stratification of granite in this theory1 #cja4 ,if granitic veins were found proceeding from real granitic strata1 they could not be explained on the principles here laid down1 #cjb4 ,no such veins have been discovered1 #cjc4 ,answer to an objection made to the igneous origin of granitic mountains1 #cjd1 #cje4 ,of the proportion of the earth's surface occupied by granite rocks1 #cjf4 ,not exceeding a ninetieth part1 #cjg1 #caa4 ,extent of granite in ,scotland erroneously estimated by ,dr ,hutton1 #cab4 ,amounts perhaps to a twenty-fourth of the whole surface1 #cac4 ,observations on ,mr ,kirwan's opinion1 #cad4 ,,note ,,xvi4--,rivers and ,lakes4 p4 #cej ,the rivers have hollowed out the valleys1 #cae4 ,illustration from the course of the ,danube1 #caf4 ,courses of many rivers retain marks of having consisted of a series of lakes1 #cag1 #cah4 ,filling up and draining of lakes1 #cbj4 ,instances from the lakes in ,cumberland1 #cba4 ,lake of ,geneva1 #cbb4 ,lakes in ,north ,america1 ib4 ,cataracts1 #cbc4 ,difficulties in explaining the generation and continuance of lakes exemplified in that of ,geneva1 #cbd4 ,attempt to resolve these difficulties1 #cbe1 #cbf1 #cbg1 #cbh4 ,all lakes not equally subject to them1 #cbi4 ,wasting of the land by the rivers1 proved from the mouths of rivers on bold coasts1 #ccj4 ,examples from ,cornwall1 #cca4 ,,note ,,xvii4--,remains of ,decomposed ,rocks4 p4 #cga ,plain of ,crau1 #ccd4 ,its gravel from the decomposition of pudding-stone1 #che4 ,same true of much of the gravel in this island1 #ccg1 #cch4 ,mount ,rigi in ,switzerland the remains of a body of pudding-stone1 #cci4 ,measure of the destruction in the stratified rocks sometimes1 afforded by the unstratified1 #cdj1 #cda4 ,rate at which the elevation of mountains has been supposed to decrease1 #cdb4 ,,note ,,xviii4--,transportation of ,stones1 c4 p4 #cha ,gravel smaller and rounder the farther from its native place1 #cdc4 ,different sources of caillou rouls1 #cdd1 #cde4 ,stones that have begun their migration before the cutting out of the present valleys1 #cdf4 ,declivity necessary to enable stones to travel from the top of ,mont ,blanc to the top of ,mont ,jura1 #cdg4 ,granite from ,mont ,blanc found eastward in the valley of the ,drance1 #cdh4 ,machinery employed by nature in transporting rocks1 #cdi1 #cej4 ,instances of transported stones of great size1--from the vicinity of ,geneva1 #cea1 #ceb1--;from the ,isle of ,arran1 #cec4 ,how gravity may contribute to the moving of large stones1 even when the declivity is small1 #ced4 ,rocking-stones1 #cee4 ,stone in ,borrowdale1--in the valley of ,urseren1 #cef4 ,large stones are sometimes the remains of veins1 #ceg4 ,of the hypothesis of a debacle1 #ceh4 ,structure of valleys unfavourable to this hypothesis1 #cei1 #cfj4 ,particularly of valleys close at the ends1 #cfa1 #cfb4 ,whether the supposition of a debacle is necessary to explain the moving of large masses of rock1 #cfd4 ,whether the abrupt faces of hills indicate the existence of any sudden torrent1 c4 #cfe4 ,fact concerning the steep faces of the mountains in the south of ,africa1 #cff4 ,a fact stated that would lead necessarily to belief in a debacle2 no example of it has yet occurred1 #cfg4 ,,note ,,xix4--,transportation of ,materials by the ,sea4 p4 #dac ,of the manner in which the detritus of the land is spread out over the bottom of the sea1 #cfi1 #cgj4 ,seas rendered shallower1 #cga4 ,sand banks1 #cgb4 ,great system of currents traced in the ,atlantic1 #cgc1 #cgd4 ,how far this transportation of materials may affect the earth's diurnal motion1 #cgf1 #cgg4 ,kirwan's misapprehension of ,frisi1 and of ,major ,rennell1 #cgh1 #cgi4 ,his mistake about the tides1 #chj1 #cha1--;and about the formation of sand banks1 #chd4 ,,note ,,xx4--,inequalities of the ,planetary ,motions4 p4 #dcg ,these inequalities all periodical1 #che4 ,circumstances on which this depends1 #chf4 ,affinity of this conclusion to that which ,dr ,hutton has established with respect to the changes at the surface of the earth1 #chg4 ,,note ,,xxi4--,changes in the ,apparent ,level of the ,sea4 p4 #dda ,relative level of the sea and land subject to change1 #chh4 ,proofs that it has sunk1 on the shores of this island1 #chi1--on the coasts of ,france and ,flanders1 #cij1 #cia1--on the shores of the ,baltic1 #cib4 ,this has not arisen from the depression of the sea1 but from the elevation of the land1 #cic1 #cid4 ,the surface of the ,hadriatic higher now than formerly1 #cie1 #cif4 ,also of the ,mediterranean1 #cih4 ,irregularities in these changes1 #cii1 #djj4 ,hypothesis of ,frisi1 that towards the equator the sea is every where rising1 #dja4 ,disproved1 ib4 ,conclusion1 #djb4 ,,note ,,xxii4--,fossil ,bones4 p4 #deh ,vegetable and animal remains contained in the fossil kingdom1 #djc4 ,of those that are enveloped or penetrated with calcareous earth1 #dje1 #djf4 ,of the bones buried in the loose earth1 #djg4 ,bones in ,siberia referred to the rhinoceros and the elephant1 #djh4 ,those on the ,ohio doubtful1 #djh1 #dji4 ,opinion of ,camper1 #daj4--of ,cuvier1 #daa4 ,objections to the latter1 ib4 ,enumeration of five species of animals now extinct1 #dab4 ,change in the animal1 and vegetable kingdom may account for bones found in countries where no analogous species now exists1 #dad4 ,proofs that the animals whose bones are found in ,siberia inhabited that country1 #dae-dag4 ,,note ,,xxiii4--,geology of ,kirwan and ,de ,luc4 p4 #dgg ,these authors have improperly drawn religion into their quarrel with ,dr ,hutton1 #dai4 ,de ,luc writes a history of what befel the earth before the creation of the sun1 #dbj4 ,remarks on ,kirwan's geological writings1 #dbb1 #dbc1 #dbd1 #dbe4 ,,note ,,xxiv4--,system of ,buffon4 p4 #dhc ,in what ,buffon's theory of the earth and ,dr ,hutton's agree1 and in what they differ1 #dbf1 #dbg4 ,great merit of ,buffon1 notwithstanding his errors1 #dbh4 ,,note ,,xxv4--,figure of the ,earth4 p4 #dhh ,physical cause of the earth's oblate figure not obvious from its present condition1 #dbi4 ,how explained by the ,neptunists1 #dcj4 ,examination of their solution1 #dca1 #dcb4 ,contradiction implied in it1 #dcc4 ,insufficiency of ,buffon's explanation1 #dcd4 ,of the principle on which the oblateness of the earth may be accounted for in ,dr ,hutton's theory1 #dce4 ,of the changes that would happen in the figure of a terraqueous body like the earth1 supposing it ever so irregular1 #dcf1 #dcg1 #dch4 ,two different causes of change1 ib4 ,ultimate figure1 that by which the causes of change are best resisted1 #dci4 ,spheroidal figure1 never perfectly acquired1 #ddj4 ,agreement of this theory with observation1 #dda4 ,probable extension of the system of waste1 and renovation to the other planets1 #ddb1 #ddc4 ,confirmation from the system of ,saturn1 #ddd1 #dde4 ,,note ,,xxvi4--,prejudices relating to the ,theory of the ,earth4 p4 #eaj ,alleged by some that a theory of the earth ought not at present to be attempted1 #ddf4 ,the quick succession of geological theories has partly arisen from their object being misunderstood1 #ddg4 ,a succession of theories is often a continued approximation to the truth1 #ddh4 ,the more various the phenomena of any class1 the greater the chance of discovering their true cause1 #ddi4 ,reason to think that the leading facts in geology are now known1 #dej1 #dea4 ,a tendency may be observed in geological systems to approach to one another1 and to the ,huttonian1 #deb4 ,example from that of ,saussure1 #dec1--of ,dolomieu1 #ded1 #dee4 ,the discoveries of ,dr ,black were necessary for understanding the true theory of the earth1 #deg4 ,use of theory in matters of observation1 #deh1 c4 ,,illustrations1 c4 ,a ,,very little attention to the phenomena of the mineral kingdom1 is sufficient to convince us1 that the condition of the earth's surface has not been the same at all times that it is at the present moment4 ,when we observe the impressions of plants in the heart of the hardest rocks2 when we discover trees converted into flint1 and entire beds of limestone or of marble composed of shells and corals2 we see the same individual in two states1 the most widely different from one another2 and1 in the latter instance1 have a clear proof1 that the present land was once deep immersed under the waters of the ocean4 ,if to this we add1 that many masses of rock1 the most solid and compact1 consist of no other materials but sand and gravel2 that1 on the other hand1 loose gravel1 such as is formed only in beds of rivers1 or on the sea shore1 now abounds in places remote from both3 if we reflect1 at the same time1 on the irregular and broken figure of our continents1 and the identity of the mineral strata on opposite sides of the same valley1 or the same inlet of the sea2 we shall see abundant reason to conclude1 that the earth has been the theatre of many great revolutions1 and that nothing on its surface has been exempted from their effects4 ,to trace the series of these revolutions1 to explain their causes1 and thus to connect together all the indications of change that are found in the mineral kingdom1 is the proper object of a ,,theory ,,of ,,the ,,earth4 ,but1 though the attention of men may be turned to the theory of the earth by a very superficial acquaintance with the phenomena of geology1 the formation of such a theory requires an accurate and extensive examination of those phenomena1 and is inconsistent with any but a very advanced state of the physical sciences4 ,there is1 perhaps1 in those sciences1 no research more arduous than this2 none certainly where the subject is so complex2 where the appearances are so extremely diversified1 or so widely scattered1 and where the causes that have operated are so remote from the sphere of ordinary observation4 ,hence the attempt6 to form a theory of the earth are of very modern origin1 and as1 from the simplicity of its subject astronomy is the eldest1 so1 on account of the complexness of its subject1 geology is the youngest of the sciences4 ,it is foreign from the present purpose to enter on any history of the systems that1 since the rise of this branch of science1 have been invented to explain the phenomena of the mineral kingdom4 ,it is sufficient to remark1 that these systems are usually reduced to two classes1 according as they refer the origin of terrestrial bodies to ,,fire or to ,,water2 and that1 conformably to this division1 their followers have of late been distinguished by the fanciful names of ,vulcanists and ,neptunists4 ,to the former of these ,dr ,hutton belongs much more than to the latter2 though1 as he employs the agency both of fire and of water in his system1 he cannot1 in strict propriety1 be arranged with either4 ,in the succinct account which ,i am now about to give of this system1 ,i shall consider the mineral kingdom as divided into two parts1 namely1 stratified and unstratified substances ,i shall treat1 first1 of the phenomena peculiar to the stratified2 next1 of those peculiar to the unstratified2 and1 lastly1 of the phenomena common to both4 ,beginning1 then1 with the first1 the subject naturally divides itself into three branches2 viz4 the materials the consolidation1 and the position of the strata4 ,,section ,i4 ,,of ,,the ,,phenomena ,,peculiar ,,to ,,stratified ,,bodies4 #a4 ,materials of the ,strata4 #a4 ,,it is well known that1 on removing the loose earth which forms the immediate surface of the land1 we come to the solid rock1 of which a great proportion is found to be regularly disposed in strata1 or beds of determinate thickness1 inclined at different angles to the horizon1 but separated from one another by equidistant superficies1 that often maintain their parallelism to a great extent4 ,these strata bear such evident marks of being deposited by water1 that they are universally acknowledged to have had their origin at the bottom of the sea2 and it is also admitted1 that the materials which they consist of1 were then either soft1 or in such a state of comminution and separation1 as renders them capable of arrangement by the action of the water in which they were immersed4 ,thus far most of the theories of the earth agree2 but from this point they begin to diverge1 and each to assume a character and direction peculiar to itself4 ,dr ,hutton's does so1 by laying down this fundamental proposition1 ,that in all the strata we discover proofs of the materials having existed as elements of bodies1 which must have been destroyed before the formation of those of which these materials now actually make a part4#a ,footnote #a3 ,hutton's ,theory1 vol4 ,i p4 #bj1 c4 #b4 ,the calcareous strata are the portion of the mineral kingdom that gives the clearest testimony to the truth of this assertion4 ,they often contain shells1 corals1 and other exuvi of marine animals in so great abundance1 that they appear to be composed of no other materials4 ,though these remains of organized bodies are now converted into stone or into spar1 their shape and interior structure are often so well preserved1 that the species of animal or plant of which they once made a part1 can still be distinguished and pointed out among the living inhabitants of the ocean4 ,others of the calcareous strata appear to be composed of fragments of some ancient rocks1 which1 after having been broken1 have been again united into a compact stone4 ,in these we find pieces clearly marked as having been once continuous but now placed at a distance from one another1 and exhibiting exactly the same appearances as if they floated in a fluid of the same specific gravity with themselves4 ,from these1 therefore1 and a variety of similar appearances1 ,dr ,hutton concludes1 that the materials of all the calcareous strata have been furnished1 either from the dissolution of former strata1 or from the remains of organized bodies4 ,but1 though this conclusion is meant to be extended to all the calcareous strata1 it is not asserted that every cubic inch of marble or of limestone contains in it the characters of its former condition1 and of the changes through which it has passed4 ,it may1 however1 be safely affirmed1 that there is scarce any entire stratum where such characters are not to be found4 ,these must be held as decisive with respect to the whole system of strata to which they belong2 they prove the existence of calcareous rocks before the formation of the present2 and1 as the destruction of those is evidently adequate to the supply of the materials of these that we now see1 to look for any other supply were superfluous1 and could only embarrass our reasonings by the introduction of unnecessary hypotheses4#b ,footnote #b3 ,,note ,i4 #c4 ,the same conclusions result from an examination of the siliceous strata2 under which we may comprehend the common sandstone1 and also those pudding-stones or breccias where the gravel consists of quartz4 ,in all these instances1 it is plain1 that the sand or gravel existed in a state quite loose and unconnected1 at the bottom of the sea1 previous to its consolidation into stone4 ,but such bodies of gravel or sand could only be formed from the attrition of large masses of quartz1 or from the dissolution of such sandstone strata as exist at present2 for it will hardly be alleged1 that sand is a crystallization of quartz1 formed from that substance1 when it passes from a fluid to a solid state4 ,those pudding-stones in which the gravel is round and polished1 carry the conclusion still farther1 as such gravel can only be formed in the beds of rivers or on the shores of the sea2 for1 in the depths of the ocean1 though currents are known to exist1 yet there can be no motion of the water sufficiently rapid to produce the attrition required to give a round figure and smooth surface to hard and irregular pieces of stone4 ,there must have existed1 therefore1 not only a sea1 but continents1 previously to the formation of the present strata4 ,the same thing is clearly shown by those petrifactions of wood1 where1 though the vegetable structure is perfectly preserved1 the whole mass is siliceous1 and has1 perhaps1 been found in the heart of some mountain1 deep imbedded in the solid rock4 #d4 ,characters of the same import are also found among the argillaceous strata1 though perhaps more rarely than among the calcareous or siliceous4 ,such are the impressions of the leaves and stems of vegetables2 also the bodies of fish and amphibious animals1 found very often in the different kinds of argillaceous schistus1 and in most instances having the figure accurately preserved1 but the substance of the animal replaced by clay or pyrites4 ,these are all remains of ancient seas or continents2 the latter of which have long since disappeared from the surface of the earth1 but have still their memory preserved in those archives1 where nature has recorded the revolutions of the globe4 #e4 ,among bituminous bodies1 pit-coal is the only one which constitutes regular and extensive strata2 and no fossil has its origin from the waste of former continents1 marked by stronger and more distinct characters4 ,not to mention that the coal strata are alternated with those that have been already enumerated1 and that they often contain shells and corals1 perfectly mineralized1 it is sufficient to remark1 that there are entire beds of this fossil1 which appear to consist wholly of wood1 and in which the fibrous structure is perfectly preserved4 ,from these instances1 the appearances of vegetable structure may be traced through all possible gradations1 down to an evanescent state4 ,this last state is undoubtedly the most common2 and though coal does not then1 on bare inspection1 make known its vegetable origin1 yet1 if we take it in connection with the other terms of the series1 as we may call them2 if we consider that the two extremes1 viz4 coal1 with the vegetable structure perfect1 and coal without any such structure visible1 are often found in the same or in contiguous beds2 and1 if we remark1 that through all these gradations coal contains nearly the same chemical elements1 and yields1 on analysis1 bitumen and charcoal1 combined with a greater or less proportion of earth3 if we take all these circumstances into account1 we cannot doubt that this fossil is every where the same1 and derives its origin from the trees and plants that grew on the surface of the earth before the formation of the present land4 #f4 ,dr ,hutton has further observed1 that if those ancient continents were at all similar to the present1 we can be at no loss to account for the want of any distinct mark of vegetable organization in the greater part of the coal strata4 ,it is plain1 that the daily waste of animal and vegetable substances on the surface of the earth1 must disengage a great quantity of oily as well as carbonic matter1 which1 with whatever element it is at first combined1 is ultimately delivered into the ocean4 ,thus1 the oily or fuliginous parts of animal and vegetable substances1 let loose by burning1 first ascend into the atmosphere1 but are at length precipitated1 and either fall immediately into the sea1 or are1 in part at least1 washed down into it from the land4 ,from other causes also1 much vegetable matter is carried down by the rivers2 and the whole quantity of animal and vegetable substances thus delivered into the sea1 must be very considerable1 amounting annually to the whole residuum of those substances1 not employed in the maintenance or reproduction of animal and vegetable bodies4 ,whether chemically united to the waters of the ocean1 or simply suspended in them1 this matter is at last precipitated1 and1 mingling with earthy substances1 is formed into strata1 the place of which will be determined by the currents1 the position of the present continents1 and many other circumstances not easily enumerated4 ,if1 then1 an order of things similar to what we now see1 existed before the formation of the present strata1 it would necessarily happen1 that the animal and vegetable substances1 diffused through the ocean1 being separated from the water1 would be deposited at the bottom of the sea1 and1 in the course of ages1 would form beds1 less or more pure1 according to the quantity of earth and other substances deposited at the same time4 ,these beds being consolidated and mineralized by operations that are afterwards to be considered1 have been converted into pit-coal1 the parts of which are impalpable1 and retain nothing of their primitive structure4#c ,footnote #c3 ,,note ,,ii4 ,if1 then1 the formation of coal from animal and vegetable bodies be admitted1 the general position which derives the origin of the strata from the waste of former land1 as it is applicable to all the kinds already enumerated1 and of course to all those with which they are alternated1 comprehends a very large portion of the earth's surface4 ,it comprehends1 indeed1 all the strata usually distinguished by the name of ,secondary2 but there is another great division of the mineral kingdom1 viz4 the rocks1 called ,primitive1 which1 as they are never alternated with the secondary1 but are always inferior to them1 must be further examined1 before we can decide whether the same conclusion extends to them or not4 #g4 ,here it must be carefully observed1 that1 among the primary rocks1 the granite is not meant to be included1 except where that stone is stratified1 and either coincides with veined granite or with gneiss4 ,the primitive strata1 in ,dr ,hutton's theory1 comprehend1 besides gneiss1 the micaceous1 chlorite1 hornblende1 and siliceous schistus1 together with slate1 and some other kinds of argillite2 to which we must add1 serpentine1 micaceous limestone1 and the greater part of marbles4 ,these are mostly distinguished by their laminated structure1 by having their planes much elevated with respect to the horizon1 and by belonging more to the mountainous than the level parts of the earth's surface4 ,they rarely contain vestiges of organized bodies2 so rarely1 indeed1 that they were called primitive by the geologists who first distinguished them from other rocks1 on the supposition of their being part of the primeval nucleus of the globe1 which had never undergone any change whatsoever2 but this1 ,i believe1 has now almost ceased to be the opinion of any geologist4#d ,the ,neptunists hold the rocks1 here enumerated1 and also granite1 to be produced by aqueous deposition2 but maintain them to be in the strictest sense primeval1 and of a formation antecedent to all organized bodies4 ,footnote #d3 ,,note ,,iii4 #h4 ,in opposition to this1 ,dr ,hutton maintained1 that the primary schistus1 like all the other strata1 was formed of materials deposited at the bottom of the sea1 and collected from the waste of rocks still more ancient4 ,when1 therefore1 he conformed to the received language of mineralogists1 by calling these strata primitive1 he only meant to describe them as more ancient than any other strata now existing1 but not as more ancient than any that ever had existed4 ,they are distinguished1 in his system1 by the name of ,primary1 rather than of ,primitive strata4 ,that the account now given of their origin is well founded1 may be proved by unquestionable facts4 ,for1 first1 though1 agreeably to the observation just made1 the ancient strata do but rarely contain any remains of organized bodies1 they are not entirely destitute of them4 ,different places in this island have been pointed out by ,dr ,hutton1 where marine objects have been discovered in primary limestone1 either by himself or others1 and it would not be difficult to add more instances of the same kind4#e ,in ,dauphine1 coal1 which is certainly a derivative substance1 has been found among mountains which have a title to the character of primitive1 such as no one will dispute4 ,these facts put the composition of such rocks from loose materials1 beyond all doubt1 and also prove their formation to be posterior to the existence of an animal and vegetable system4 ,they do indeed prove this in the strictest sense1 only of the particular beds in which they are found2 but as these beds are in all other respects as much to be accounted primary as any part of the mineral kingdom1 it is evident that the negative instances are here of no force1 and that nothing can be gained to the adversaries of this opinion by denying it in general1 if they are obliged to admit it in a single case4 ,footnote #e3 ,,note ,,iv4 #i4 ,again1 it is certain1 as ,dr ,hutton remarks1 that there are few considerable bodies of schistus1 even the most decidedly primitive1 where sand and gravel may not in some parts be observed4 ,indeed1 it is not only true that they are to be found in some parts of them2 but1 in fact1 among many of the primitive mountains1 we find large tracts1 composed entirely of a schistose and much indurated sandstone1 in beds highly inclined1 sometimes alone1 sometimes alternated with other schisti4 ,in many of them1 the sand of which they consist appears to be entirely of granite1 from the detritus of which rock it should seem that they were chiefly formed4 #aj4 ,thus we conclude1 that the strata both primary and secondary1 both those of ancient and those of more recent origin1 have had their materials furnished from the ruins of former continents1 from the dissolution of rocks1 or the destruction of animal or vegetable bodies1 similar1 at least in some respects1 to those that now occupy the surface of the earth4 ,this conclusion is not indeed proved of every individual portion of rock1 but it is demonstrated of many and large parts1 and those scattered indifferently through all the varieties of the strata2 and therefore1 from the rules of the strictest reasoning1 we must infer1 that the whole is derived from the same origin4#f ,footnote #f3 ,,note ,v4 ,thus far concerning the materials of the strata2 and1 as these were originally loose and unconnected1 we must next consider by what means they were consolidated into stone4 #b4 ,consolidation of the ,strata4 #aa4 ,though ,dr ,hutton has no where defined the meaning of the term consolidation1 he has been scrupulously exact in using it constantly in the same sense4 ,he understands by it1 not merely that quality in a hard body1 by which its parts cohere together1 but also that by which it fills up the space comprehended within its surface1 being to sense without porosity1 and impervious to air and moisture4 ,now1 a porous mass of unconnected materials1 such as the strata appear originally to have been1 can acquire hardness and solidity only in two ways1 that is1 either when it is first reduced by heat into a state of fusion1 or at least of softness1 and afterwards permitted to cool2 or when matter that is dissolved in some fluid menstruum1 is introduced along with that menstruum into the porous mass1 and1 being deposited1 forms a cement by which the whole is rendered firm and compact4 ,fire and water1 therefore1 are the only two physical agents to which we can ascribe the consolidation of the strata2 and1 in order to determine to which of them that effect is to be attributed1 we must inquire whether there are any certain characters that distinguish the action of the one from that of the other1 and which may be compared with the phenomena actually observed among mineral substances4 #ab4 ,first1 then1 it is evident1 that the consolidation produced by the action of water1 or of another fluid menstruum1 in the manner just referred to1 must necessarily be imperfect1 and can never entirely banish the porosity of the mass4 ,for the bulk of the solvent1 and of the matter it contained in solution1 being greater than the bulk of either taken singly1 when the latter was deposited1 the former would have sufficient room left1 and would continue to occupy a certain space in the interior of the strata4 ,a liquid solvent1 therefore1 could never shut up the pores of a body to the entire exclusion of itself2 and1 had mineral substances been consolidated1 as here supposed1 the solvent ought either to remain within them in a liquid state1 or if evaporated1 should have left the pores empty and the body pervious to water4 ,neither of these however1 is the fact2 many stratified bodies are perfectly impervious to water1 and few mineral substances contain water in a liquid state4 ,that they sometimes contain it1 chemically united to them1 is no proof of their solidity having been brought about by that fluid2 for such chemical union is as consistent with the supposition of igneous as of aqueous consolidation1 since the region in which the fire was applied1 on every hypothesis must have abounded with humidity4 #ac4 ,again1 if water was the solvent by which the consolidating matter was introduced into the interstices of the strata1 that matter could consist only of such substances as are soluble in water1 whereas it consists of a vast variety of substances1 altogether insoluble either in it1 or in any single menstruum whatsoever4 ,the strata are consolidated1 for example1 by quartz1 by fluor1 by feldspar1 and by all the metals1 in their endless combinations with sulphureous bodies4 ,to affirm that water was ever capable of dissolving these substances1 is to ascribe to it powers which it confessedly has not at present2 and1 therefore1 it is to introduce an hypothesis1 not merely gratuitous1 but one which1 physically speaking1 is absurd and impossible4 ,this is not all1 however2 for1 even if this difficulty were to be passed over1 it would still be required to explain1 how the water1 which1 together with the matter which it held in solution1 had insinuated itself into the pores of the strata1 became suddenly disposed to deposit that matter1 and to allow it1 by crystallization or concretion1 to assume a solid form4#g ,the ,neptunists must either assign a sufficient reason for this great and universal change1 or must expect to see their system treated as an inartificial accumulation of hypotheses which assigns opposite virtues to the same subject1 and is alike at variance with nature and with itself2 in a word1 a system that might pass for the invention of an age1 when as yet sound philosophy had not alighted on the earth1 nor taught man that he is but the minister and interpreter of nature1 and can neither extend his power nor his knowledge a hair's-breadth beyond his experience and observation of the present order of things4#h ,footnote #g3 ,,note ,,vi4 ,footnote #h3 ,homo natur minister1 et interpres tantm facit et intelligit1 quantm de natur ordine re1 vel mente1 observaverit3 nec amplius scit1 aut potest4--,nov4 ,org4 lib4 i4 aph4 #a4 #ad4 ,such are the more obvious1 but ,i think unanswerable objections1 that may be urged against the aqueous consolidation of the strata4 ,it is true1 that stony concretions1 some of them much indurated1 are formed in the humid way under our eyes4 ,very particular conditions1 however1 are required for that purpose1 and conditions such as can hardly have existed at the bottom of the sea4 ,first4 ,the water must dissolve the substance of which the concretion is to be formed1 as it actually does in the case of calcareous1 and in certain circumstances1 in that of siliceous1 earth4 ,secondly4 ,it must be separated from that substance1 as by evaporation1 or by a combination of the matter dissolved with some third substance1 to which it has a greater affinity than to water1 so as to form with it an insoluble compound4 ,lastly1 the water that is deprived of its solution must be carried off1 and more of that which contains the solution must be supplied1 as sometimes happens where water runs in a stream1 or drops from the roof of a cavern4 ,the two last conditions are peculiarly inapplicable to the bottom of the sea1 where the state of the surrounding fluid would neither permit the water that was deprived of its solution from being drawn off1 nor that which contained the solution from succeeding it4 ,it is further to be observed1 that the consolidation of stalactitical concretions1 that is1 the filling up of their pores1 is always imperfect1 and is brought about by the repeated action of the fluid running through the porous mass1 and continuing to deposit there some of the matter it holds in solution4 ,this1 which is properly infiltration1 is incompatible with the nature of a fluid1 either nearly1 or altogether quiescent4 #ae4 ,in order to judge whether objections of equal weight can be opposed to the hypothesis of igneous consolidation1 we must attend to a very important remark1 first made by ,dr ,hutton1 and applied with wonderful success to explain the most mysterious phenomena of the mineral kingdom4 ,it is certain1 that the effects of fire on bodies vary with the circumstances under which it is applied to them1 and1 therefore1 a considerable allowance must be made1 if we would compare the operation of that element when it consolidated the strata1 with the results of our daily experience4 ,the materials of the strata were disposed1 as we have already seen1 loose and unconnected1 at the bottom of the sea2 that is1 even on the most moderate estimation1 at the depth of several miles under its surface4 ,at this depth1 and under the pressure of a column of water of so great a height1 the action of heat would differ much from that which we observe here upon the surface2 and1 though our experience does not enable us to compute with accuracy the amount of this difference1 it nevertheless points out the direction in which it must lie1 and even marks certain limits to which it would probably extend4 ,the tendency of an increased pressure on the bodies to which heat is applied1 is to restrain the volatility of those parts which otherwise would make their escape1 and to force them to endure a more intense action of heat4 ,at a certain depth under the surface of the sea1 the power even of a very intense heat might therefore be unable to drive off the oily or bituminous parts from the inflammable matter there deposited1 so that1 when the heat was withdrawn1 these principles might be found still united to the earthy and carbonic parts1 forming a substance very unlike the residuum obtained after combustion under a pressure no greater than the weight of the atmosphere4 ,it is in like manner reasonable to believe1 that1 on the application of heat to calcareous bodies under great compression1 the carbonic gas would be forced to remain2 the generation of quicklime would be prevented1 and the whole might be softened1 or even completely melted2 which last effect1 though not directly deducible from any experiment yet made1 is rendered very probable1 from the analogy of certain chemical phenomena4 #af4 ,an analogy of this kind1 derived from a property of the barytic earth1 was suggested by that excellent chemist and philosopher1 the late ,dr ,,black4 ,the barytic earth1 as is well known1 has a stronger attraction for fixed air than common calcareous earth has1 so that the carbonate of barytes is able to endure a great degree of heat before its fixed air is expelled4 ,accordingly1 when exposed to an increasing heat1 at a certain temperature1 it is brought into fusion1 the fixed air still remaining united to it3 if the heat be further increased1 the air is driven off1 the earth loses its fluidity1 and appears in a caustic state4 ,here1 it is plain1 that the barytic earth1 which is infusible1 or very refractory1 per se1 as well as the calcareous1 owes its fusibility to the presence of the fixed air2 and it is therefore probable1 that the same thing would happen to the calcareous earth1 if by any means the fixed air were prevented from escaping when great heat is applied to it4 ,this escape of the fixed air is exactly what the compression in the subterraneous regions is calculated to prevent1 and therefore we are not to wonder if1 among the calcareous strata1 we find marks of actual fusion having taken place4#i ,footnote #i3 ,,note ,,vii4 #ag4 ,these effects of pressure to resist the decomposition1 and augment the fusibility of bodies1 being once supposed1 we shall find little difficulty in conceiving the consolidation of the strata by heat1 since the intervals between the loose materials of which they originally consisted may have been closed1 either by the softening of those materials1 or by the introduction of foreign matter among them1 in the state of a fluid1 or of an elastic vapour4 ,no objection to this hypothesis can arise from the considerations stated in the preceding case2 the solvent here employed would want no pores to lodge in after its work was completed1 nor would it find any difficulty in making its retreat through the densest and most solid substances in the mineral kingdom4 ,neither can its incapacity to dissolve the bodies submitted to its action be alleged4 ,heat is the most powerful and most general of all solvents2 and1 though some bodies1 such as the calcareous1 are able to resist its force on the surface of the earth1 yet1 as has just been shown1 it is perfectly agreeable to analogy to suppose1 that1 under great pressure1 the carbonic state of the lime being preserved1 the purest limestone or marble might be softened1 or even melted4 ,with respect to other substances1 less doubt of their fusibility is entertained2 and though1 in our experiments1 the refractory nature of siliceous earth has not been completely subdued1 a degree of softness and an incipient fusion have nevertheless been induced4 ,thus it appears1 in general1 that the same difficulties do not press against the two theories of aqueous and of igneous consolidation2 and1 that the latter employs an agent incomparably more powerful than the former1 of more general activity1 and1 what is of infinite importance in a philosophical theory1 vastly more definite in the laws of its operation4 #ah4 ,a more particular examination of the different kinds of fossils will confirm this conclusion1 and will show1 that1 wherever they bear marks of having been fluid1 these marks are such as characterize the fluidity of fusion1 and distinguish it from that which is produced by solution in a menstruum4 ,dr ,hutton has enumerated many of these discovered in the course of that careful and accurate examination of fossils1 in which he probably never was excelled by any mineralogist4 ,it will be sufficient here to point out a few of the most remarkable examples4 #ai4 ,fossil wood1 penetrated by siliceous matter1 is a substance well known to mineralogists2 it is found in great abundance in various situations1 and frequently in the heart of great bodies of rock4 ,on examination1 the siliceous matter is often observed to have penetrated the wood very unequally1 so that the vegetable structure remains in some places entire2 and in other places is lost in a homogeneous mass of agate or jasper4 ,where this happens1 it may be remarked1 that the line which separates these two parts is quite sharp and distinct1 altogether different from what must have taken place1 had the flinty matter been introduced into the body of the wood1 by any fluid in which it was dissolved1 as it would then have pervaded the whole1 if not uniformly1 yet with a regular gradation4 ,in those specimens of fossil wood that are partly penetrated by agate1 and partly not penetrated at all1 the same sharpness of termination may be remarked1 and is an appearance highly characteristic of the fluidity produced by fusion4 #bj4 ,the round nodules of flint that are found in chalk1 quite insulated and separate from one another1 afford an argument of the same kind2 since the flinty matter1 if it had been carried into the chalk by any solvent1 must have been deposited with a certain degree of uniformity1 and would not now appear collected into separate masses1 without any trace of its existence in the intermediate parts4 ,on the other hand1 if we conceive the melted flint to have been forcibly injected among the chalk1 and to have penetrated it1 somewhat as mercury may1 by pressure1 be made to penetrate through the pores of wood1 it might1 on cooling1 exhibit the same appearances that the chalk-beds of ,england do actually present us with4 ,the siliceous pudding-stone is an instance closely connected with the two last2 in it we find both the pebbles1 and the cement which unites them1 consisting of flint equally hard and consolidated2 and this circumstance1 for which it is impossible to account by infiltration1 or the insinuation of an aqueous solvent1 is perfectly consistent with the supposition1 that a stream of melted flint has been forcibly injected among a mass of loose gravel4 #ba4 ,the common grit1 or sandstone1 though it certainly gives no indication of having possessed fluidity1 is strongly expressive of the effects of heat4 ,it is so1 especially in those instances where the particles of quartzy sand1 of which it is composed1 are firmly and closely united1 without the help of any cementing substance whatsoever4 ,this appearance1 which is very common1 seems to be quite inconsistent with every idea of consolidation1 except an incipient fusion1 which1 with the assistance of a suitable compression1 has enabled the particles of quartz to unite into stone4 ,it has indeed been asserted1 that the mere apposition of stony particles1 so as to permit their corpuscular attraction to take place1 was sufficient to form them into stone4 ,to this ,dr ,hutton has very well replied1 that1 admitting the possibility of a hard and firm body being produced in this way of which1 however1 we have no proof1 the close and compact texture1 the perfect consolidation of the stones we are now speaking of1 would still remain to be explained1 and of this it is evident that the mere apposition of particles1 and the force of their mutual attraction1 can afford no solution4 #bb4 ,these proofs that the strata must have endured the action of intense heat1 though immediately deduced from those of the siliceous genus only1 extend in reality to all the strata1 of every kind1 with which they are found alternated4 ,it is impossible that heat1 of the intensity here supposed1 can have acted on a particular stratum1 and not on those that are contiguous to it2 and1 as there are no strata of any kind with which the quartzy and siliceous are not intermixed1 so there are none of which the igneous consolidation is not thus rendered probable4 ,we need rest nothing1 however1 on this argument1 as the fossils of every genus may be shown to speak distinctly for themselves4 #bc4 ,those of the calcareous genus do so perhaps more sparingly than the rest2 yet even among them there are many facts1 that1 though taken unconnected with all others1 are sufficient to establish the action of subterraneous fire4 ,such1 for example1 are the calcareous breccias1 composed of fragments of marble or limestone1 and not only adapted to each other's shape1 but indented into one another1 in a manner not a little resembling the sutures of the human cranium4 ,from such instances1 it is impossible not to infer the softness of the calcareous fragments when they were consolidated into one mass4 ,now1 this softness could be induced only by heat2 for it must be acknowledged1 that the action of any other solvent is quite inadequate to the softening of large fragments of stone1 without dissolving them altogether4 #bd4 ,in many other instances it appears certain1 that the stones of the calcareous genus have been reduced by heat into a state of fluidity much more perfect4 ,thus1 the saline or finer kinds of marble1 and many others that have a structure highly crystallized1 must have been softened to a degree little short of fusion1 before this crystallization could take place4 ,even the petrifactions which abound so much in limestones tend to establish the same fact2 for they possess a sparry structure1 and must have acquired that structure in their transition from a fluid to a solid state4#aj ,footnote #aj3 ,,note ,,viii4 #be4 ,in accounting1 by the operation of heat1 for these appearances of fluidity1 ,dr ,hutton has proceeded on the principle already laid down1 as conformable to analogy1 that calcareous earth1 under great compression1 may have its fixed air retained in it1 notwithstanding the action of intense heat1 and may1 by that means1 be reduced into fusion1 or into a state approaching to it4 ,in all this ,i do not think that he has departed from the strictest rules of philosophical investigation4 ,the facts just stated prove1 that limestone was once soft1 its fragments retaining at the same time their peculiar form1 an effect to which we know of none similar but those of fire2 and1 therefore1 though we could not conjecture how heat might be applied to limestone so as to melt it1 instead of reducing it to a calx1 we should1 nevertheless1 have been forced to suppose1 that this had actually taken place in the bowels of the earth2 and was a fact which1 though we were not able to explain it1 we were not entitled to deny4 ,the principle just mentioned relieves us therefore from a difficulty1 that would have embarrassed1 but could not have overturned1 this theory of the earth4 #bf4 ,from the arguments which the argillaceous strata afford for the igneous consolidation of fossils1 ,i shall select one on which ,dr ,hutton used to lay considerable stress1 and which some of the adversaries of his system have endeavoured to refute4 ,this argument is founded on the structure of certain ironstones called septaria1 often met with among the argillaceous schistus1 particularly in the vicinity of coal4 ,these stones are usually of a lenticular or spheroidal form1 and are divided in their interior into distinct septa1 by veins of calcareous spar1 of which one set are circular and concentric1 the other rectilineal2 diverging from the centre of the former1 and diminishing in size as they recede from it4 ,now1 what is chiefly to be remarked is1 that these veins terminate before they reach the surface of the stone2 so that the matter with which they are filled cannot have been introduced from without by infiltration1 or in any other way whatsoever4 ,the only other supposition1 therefore1 that is left for explaining the singular structure of this fossil1 is1 that the whole mass was originally fluid1 and that1 in cooling1 the calcareous part separated from the rest1 and afterwards crystallized4 #bg4 ,it has been urged against this theory of the septaria1 that these stones are sometimes found with the calcareous veins extending all the way to the circumference1 and of course communicating with the outside4 ,but it must be observed1 that this fact does not affect the argument drawn from specimens in which no such communication takes place4 ,it is at best only an ambiguous instance1 that may be explained by two opposite theories1 and may be reconciled either to the notion of igneous or of aqueous consolidation3 but if there is a single close septarium in nature1 it can1 of course1 be explained only by one of these theories1 and the other must1 of necessity1 be rejected4 ,besides1 it is plain1 that a close septarium can never have been open1 though an open septarium may very well have been close2 and indeed1 as this stone is1 in certain circumstances1 subject to perpetual exfoliation1 it would be wonderful if no one was ever found with the calcareous veins reaching to the surface4 ,with regard to the light1 therefore1 that they give into their own history1 these two kinds of septaria are by no means on an equal footing2 and this may serve to show1 how necessary it is1 in all inductive reasoning1 and particularly in a subject so complex as geology1 to separate with care such phenomena as admit of two solutions1 from such as admit only of one4 #bh4 ,the bituminous strata come next to be considered2 and they are of great consequence in the present argument1 because their dissimilarity in so many particulars to all other mineral substances1 renders them what ,lord ,bacon calls an instantia singularis1 having the first rank among facts subservient to inductive investigation4 ,but though unlike in substance to other fossils1 and composed1 as has been shown1 of materials that belonged not originally to the mineral kingdom1 they agree in many material circumstances with the strata already enumerated4 ,their beds are disposed in the same manner1 and are alternated indiscriminately with those of all the secondary rocks1 and1 being formed in the same region1 must have been subject to the same accidents1 and have endured the operation of the same causes4 ,they are traversed too like the other strata1 by veins of the metals1 of spars1 of basaltes1 and of other substances2 and1 whatever argument may hereafter be derived from this to prove the action of fire on the strata so traversed1 is as much applicable to coal as to any other mineral4 ,the coal strata also contain pyrites in great abundance1 a substance that is perhaps1 more than any other1 the decided progeny of fire4 ,this compound of metal and sulphur1 which is found in mineral bodies of every kind1 ,i believe1 without any exception1 is destroyed by the contact of moisture1 and resolved into a vitriolic salt4 ,at the same time it is found in the strata1 not traversing them in veins1 which may be supposed of more recent formation than the strata themselves2 but existing in the heart of the most solid rocks1 often nicely crystallized1 and completely inclosed1 on all sides1 without the most minute vacuity4 ,the pyrites must have been present1 therefore1 when the strata were consolidated1 and it is inconceivable1 if their consolidation was brought about in the wet way1 that a substance should be so generally found in them1 the very existence of which is incompatible with humidity4 ,this argument for the igneous origin of the strata is applicable to them all1 but especially to those of coal1 as abounding with pyrites more than any other4 #bi4 ,the difficulty that here naturally present itself1 viz4 how vegetable matter1 such as coal is supposed to have been1 could be exposed to the action of intense heat1 without being deprived of its inflammable part1 is obviated by the principle formerly explained concerning the effects of compression4 ,the weight incumbent on the strata of coal1 when they were exposed to the intense heat of the mineral regions1 may have been such as to retain the oily and bituminous1 as well as sulphureous parts1 though the whole was reduced almost to fusion2 and thus1 on cooling1 the sulphur uniting with iron might crystallize1 and assume the form of pyrites4 #cj4 ,the compression1 however1 has not in every instance preserved the bituminous1 in union with the carbonic part of coal2 and hence a mark of the operation of fire quite peculiar to this fossil1 and found in those infusible kinds of it which contain no bitumen1 and burn without flame4 ,these resemble1 some of them very precisely1 and all them in a great degree1 the products obtained by the distillation of the common bituminous coal that is1 they consist of charcoal1 united to an earthy basis in different proportions4 ,it is natural therefore to conclude1 that this substance was prepared in the mineral regions by the action of heat1 which1 in some instances1 has driven off the inflammable part of the coal4 ,that the heat should1 in some cases1 have done so1 is not inconsistent with the general effect attributed to compression4 ,the conditions necessary for retaining the more volatile parts1 may not have been present every where in the same degree1 so that the latter1 though they could not escape1 may have been forced from one part of a stratum1 or body of strata1 to another4 #ca4 ,in confirmation of this it must be observed1 that1 as the fixed part of coal is thus found in the bowels of the earth1 separate from the volatile or bituminous1 so1 in the neighbourhood of coal strata1 the latter is sometimes found without any mixture of the former4 ,the fountains of naphtha and petroleum are well known2 and ,dr ,hutton has described a stratum of limestone1 lying in the centre of a coal country1 which is pervaded and tinged by bituminous matter1 through its whole mass1 and has1 at the same time1 many close cavities in the heart of it1 lined with calcareous spar1 and containing fossil pitch1 sometimes in large pieces1 sometimes in hemispherical drops1 scattered over the surface of the cavities4 ,this combination could only be effected by a part of the inflammable matter of the beds of coal underneath1 being driven off by heat1 and made to penetrate the limestone1 while it was yet soft and pervious to heated vapours4#aa ,footnote #aa3 ,,note ,,ix4 #cb4 ,hitherto we have enumerated those fossils that are either not at all1 or very sparingly soluble in water4 ,there are1 however1 saline bodies among the mineral strata1 such for instance as rock-salt1 which are readily dissolved in water2 and it yet remains to examine by what cause their consolidation has been effected4 ,here the theorists who consider water as the sole agent in the mineralization of fossils1 are indeed delivered from one difficulty1 but it is only that they may be harder pressed on by another4 ,it cannot now be said1 that the menstruum which they employ is incapable of dissolving the substances exposed to its action1 as in the case of metallic or stony bodies2 but it may very well be asked1 how the water came to deposit the salts which it held in solution1 and to deposit them so copiously as it has done in many places1 without any vestige of similar deposition in the places immediately contiguous4 ,if they refuse to call to their assistance any other than their favourite element1 they will not find it easy to answer this question1 and must feel the embarrassment of a system1 subject to two difficulties1 so nicely1 but so unhappily adjusted1 that one of them is always prepared to act whenever the other is removed4 ,if1 on the other hand1 they will admit the operation of subterraneous heat1 it appears possible1 that the local application of such heat may have driven the water1 in vapour1 from one place to another1 and by such action often repeated in the same spot1 may have produced those great accumulations of saline matter1 that are actually found in the bowels of the earth4 #cc4 ,but granting that1 either in the way just pointed out1 or in some other that is unknown1 the salt and the water have been separated1 some further action of heat seems requisite1 before a compact1 and highly indurated body1 like rock-salt1 could be produced4 ,the mere precipitation of the salt1 would1 as ,dr ,hutton has observed1 form only an assemblage of loose crystals at the bottom of the sea1 without solidity or cohesion3 and to convert such a mass into a firm and solid rock1 would require the application of such heat as was able to reduce it into fusion4 ,the consolidation of rock-salt1 therefore1 however its separation from the water is accounted for1 cannot be explained but on the hypothesis of subterraneous heat4 #cd4 ,some other phenomena that have been observed in salt mines1 come in support of the same conclusion4 ,the salt rock of ,cheshire1 which lies in thick beds1 interposed between strata of an argillaceous or marly stone1 and is itself mixed with a considerable portion of the same earth1 exhibits a very great peculiarity in its structure4 ,though it forms a mass extremely compact1 the salt is found to be arranged in round masses of five or six feet in diameter1 not truly spherical1 but each compressed by those that surround it1 so as to have the shape of an irregular polyhedron4 ,these are formed of concentric coats1 distinguishable from one another by their colour1 that is1 probably by the greater or less quantity of earth which they contain1 so that the roof of the mine1 as it exhibits a horizontal section of them1 is divided into polygonal figures1 each with a multitude of polygons within it1 having altogether no inconsiderable resemblance to a mosaic pavement4 ,in the triangular spaces without the polygons1 the salt is in coats parallel to the sides of the polygons4 ,the circumstances which gave rise to this singular structure we should in vain endeavour to define2 yet some general conclusions concerning them seem to be within our reach4 ,it is clear that the whole mass of salt was fluid at once1 and that the forces1 whatever they were1 which gave solidity to it1 and produced the new arrangement of its particles1 were all in action at the same time4 ,the uniformity of the coated structure is a proof of this1 and1 above all1 the compression of the polyhedra1 which is always mutual1 the flat side of one being turned to the flat side of another1 and never an angle to an angle1 nor an angle to a side4 ,the coats formed as it were round so many different centres of attraction1 is also an appearance quite inconsistent with the notion of deposition2 both these1 however1 are compatible with the notion of solidity acquired by the refrigeration of a fluid1 where the whole mass is acted on at the same time1 and where no solvent remains to be disposed of after the induration of the rest4 #ce4 ,another species of fossil salt exhibits appearances equally favourable to the theory of igneous consolidation4 ,this is the ,trona of ,africa1 which is no other than soda1 or mineral alkali1 in a particular state4 ,the specimen of this fossil in ,dr ,black's1 now ,dr ,hope's1 collection1 is of a sparry and radiated structure1 and is evidently part of the contents of a vein1 having a stony crust adhering to it1 on one side1 with its own sparry structure complete1 on the opposite4 ,it contains but about one sixth of the water of crystallization essential to this salt when obtained in the humid way2 and1 what is particularly to be remarked1 it does not lose this water1 nor become covered with a powder1 like the common alkali1 by simple exposure to the air4 ,it is evident1 therefore1 that this fossil does not originate from mere precipitation2 and when we add1 that in its sparry structure it contains evident marks of having once been fluid1 we have little reason to entertain much doubt concerning the principle of its consolidation4 ,thus1 then1 the testimony given to the operation of fire1 or heat1 as the consolidating power of the mineral kingdom1 is not confined to a few fossils1 but is general over all the strata4 ,how far the unstratified fossils agree in supporting the same conclusion1 will be afterwards examined4 #c4 ,position of the ,strata4#ab ,footnote #ab3 ,theory of the ,earth1 vol4 i4 p4 #abj4 #cf4 ,we have seen of what materials the strata are composed1 and by what power they have been consolidated2 we are next to inquire1 from what cause it proceeds1 that they are now so far removed from the region which they originally occupied1 and wherefore1 from being all covered by the ocean1 they are at present raised in many places fifteen thousand feet above its surface4 ,whether this great change of relative place can be best accounted for by the depression of the sea1 or the elevation of the strata themselves1 remains to be considered4 ,of these two suppositions1 the former1 at first sight1 seems undoubtedly the most probable1 and we feel less reluctance to suppose1 that a fluid1 so unstable as the ocean1 has undergone the great revolution here referred to1 than that the solid foundations of the land have moved a single fathom from their place4 ,this1 however1 is a mere illusion4 ,such a depression of the level of the sea as is here supposed1 could not happen without a change proportionally great in the solid part of the globe2 and1 though admitted as true1 will be found very inadequate to explain the present condition of the strata4 #cg4 ,supposing the appearances which clearly indicate submersion under water to reach no higher than ten thousand feet above the present level of the sea1 and of course the surface of the sea to have been formerly higher by that quantity than it is now2 it necessarily follows1 that a bulk of water has disappeared1 equal to more than a seven hundredth part of the whole magnitude of the globe4#ac ,the existence of empty caverns of extent sufficient to contain this vast body of water1 and of such a convulsion as to lay them open1 and give room to the retreat of the sea1 are suppositions which a philosopher could only be justified in admitting1 if they promised to furnish a very complete explanation of appearances4 ,but this justification is entirely wanting in the present case2 for the retreat of the ocean to a lower level1 furnishes a very partial and imperfect explanation of the phenomena of geology4 ,it will not explain the numberless remains of ancient continents that are involved1 as we have seen1 in the present1 unless it be supposed that the ancient ocean1 though it rose to so great a height1 had nevertheless its shores1 and was the boundary of land still higher than itself4 ,and1 as to that which is now more immediately the object of inquiry1 the position of the strata1 though the above hypothesis would account in some sort for the change of their place1 relatively to the level of the sea2 yet1 if it shall be proved1 that the strata have changed their place relatively to each other1 and relatively to the plane of the horizon1 so as to have had an angular motion impressed on them1 it is evident that1 for these facts1 the retreat of the sea does not afford even the shadow of a theory4 ,footnote #ac3 ,,note ,x4 #ch4 ,now1 it is certain1 that many of the strata have been moved angularly1 because that1 in their original position1 they must have been all nearly horizontal4 ,loose materials1 such as sand and gravel subsiding at the bottom of the sea1 and having their interstices filled with water1 possess a kind of fluidity3 they are disposed to yield on the side opposite to that where the pressure is greatest1 and are therefore1 in some degree1 subject to the laws of hydrostatics4 ,on this account they will arrange themselves in horizontal layers2 and the vibrations of the incumbent fluid1 by impressing slight motion backward1 and forward1 on the materials of these layers1 will very much assist the accuracy of their level4 ,it is not1 however1 meant to deny1 that the form of the bottom might influence1 in a certain degree1 the stratification of the substances deposited on it4 ,the figure of the lower beds deposited on an uneven surface1 would necessarily be affected by two causes2 the inclination of that surface1 on the one hand1 and the tendency to horizontality1 on the other2 but1 as the former cause would grow less powerful as the distance from the bottom increased1 the latter cause would finally prevail1 so that the upper beds would approach to horizontally1 and the lower would neither be exactly parallel to them1 nor to one another4 ,whenever1 therefore1 we meet with rocks1 disposed in layers quite parallel to one another1 we may rest assured1 that the inequalities of the bottom have had no effect1 and that no cause has interrupted the statical tendency above explained4 ,now1 rocks having their layers exactly parallel1 are very common1 and prove their original horizontally to have been more precise than we could venture to conclude from analogy alone4 ,in beds of sandstone1 for instance1 nothing is more frequent than to see the thin layers of sand1 separated from one another by layers still finer of coaly1 or micaceous matter1 that are almost exactly parallel1 and continue so to a great extent without any sensible deviation4 ,these planes can have acquired their parallelism only in consequence of the property of water just stated1 by which it renders the surfaces of the layers1 which it deposits1 parallel to its own surface1 and therefore parallel to one another4 ,though such strata1 therefore1 may not now be horizontal1 they must have been so originally2 otherwise it is impossible to discover any cause for their parallelism1 or any rule by which it can have been produced4 #ci4 ,this argument for the original horizontality of the strata1 is applicable to those that are now farthest removed from that position4 ,among such1 for instance1 as are highly inclined1 or even quite vertical1 and among those that are bent and incurvated in the most fantastical manner1 as happens more especially in the primary schisti1 we observe1 through all their sinuosities and inflections1 an equality of thickness and of distance among their component lamin4 ,this equality could only be produced by those lamin having been originally spread out on a flat and level surface1 from which situation1 therefore1 they must afterwards have been lifted up by the action of some powerful cause1 and must have suffered this disturbance while they were yet in a certain degree flexible and ductile4 ,though the primary direction of the force which thus elevated them must have been from below upwards1 yet it has been so combined with the gravity and resistance of the mass to which it was applied1 as to create a lateral and oblique thrust1 and to produce those contortions of the strata1 which1 when on the great scale1 are among the most striking and instructive phenomena of geology4 #dj4 ,great additional force is given to this argument1 in many cases1 by the nature of the materials of which the stratified rocks are composed4 ,the beds of breccia and pudding-stone1 for instance1 are often in planes almost vertical1 and1 at the same time1 contain gravel-stones1 and other fragments of rock1 of such a size and weight1 that they could not remain in their present position an instant1 if the cement which unites them were to become soft2 and therefore they certainly had not that position at the time when this cement was actually soft4 ,this remark has been made by mineralogists who were not led to it by any system4 ,the judicious and indefatigable observer of the ,alps1 describing the pudding-stone of ,valorsine1 near the sources of the ,arve1 tells us1 that he was astonished to find it in beds almost vertical1 a situation in which it could not possibly have been formed4 ,that particles1 he adds1 of extreme tenuity1 suspended in a fluid1 might become agglutinated1 and form vertical beds1 is a thing that may be conceived2 but that pieces of stone1 of several pounds weight1 should have rested on the side of a perpendicular wall1 till they were enveloped in a stony cement1 and united into one mass1 is a supposition impossible and absurd4 ,it should be considered1 therefore1 as a thing demonstrated1 that this pudding-stone was formed in a horizontal position1 or one nearly such1 and elevated after its induration4 ,we know not1 he continues1 the force by which this elevation has been effected2 but it is an important step among the prodigious number of vertical beds that are to be met with in the ,alps1 to have found some that must certainly have been formed in a horizontal situation4#ad ,footnote #ad3 ,voyages aux ,alpes1 tom4 ii #fij4 #da4 ,nothing can be more sound and conclusive than this reasoning2 and had the ingenious author pursued it more systematically1 it must have led him to a theory of mountains very little different from that which we are now endeavouring to explain4 ,if some of the vertical strata are proved to have been formed horizontally1 there can be no reason for not extending the same conclusion to them all1 even if we had not the support of the argument from the parallelism of the layers1 which has been already stated4 #db4 ,the highly inclined position1 and the manifold inflections of the strata1 are not the only proofs of the disturbance that they have suffered1 and of the violence with which they have been forced up from their original place4 ,those interruptions of their continuity which are observed1 both at the surface and under it1 are evidences of the same fact4 ,it is plain1 that if they remained now in the situation in which they were at first deposited1 they would never appear to be suddenly broken off4 ,no stratum would terminate abruptly2 but1 however its nature and properties might change1 it would constitute an entire and continued rock1 at least where the effects of waste and detritus had not produced a separation4 ,this1 however1 is very far from being the actual condition of stratified bodies4 ,those that are much inclined1 or that make considerable angles with the horizontal plane1 must terminate abruptly where they come up to the surface4 ,their doing so is a necessary consequence of their position1 and furnishes no argument1 it may be said1 for their having been disturbed1 different from that which has been already deduced from their inclination4 ,there are1 however1 instances of a breach of continuity in the strata1 under the surface1 that afford a proof of the violence with which they have been displaced1 different from any hitherto mentioned4 ,of this nature are the slips or shifts1 that so often perplex the miner in his subterraneous journey1 and which change at once all those lines and bearings that had hitherto directed his course4 ,when his mine reaches a certain plane1 which is sometimes perpendicular1 sometimes oblique to the horizon1 he finds the beds of rock broken asunder1 those on the one side of the plane having changed their place1 by sliding in a particular direction along the face of the others4 ,in this motion they have sometimes preserved their parallelism1 that is1 the strata on one side of the slip continue parallel to those on the other2 in other cases1 the strata on each side become inclined to one another1 though their identity is still to be recognized by their possessing the same thickness1 and the same internal characters4 ,these shifts are often of great extent1 and must be measured by the quantity of the rock moved1 taken in conjunction with the distance to which it has been carried4 ,in some instances1 a vein is formed at the plane of the shift or slip1 filled with materials of the kinds which will be hereafter mentioned2 in other instances1 the opposite sides of the rock remain contiguous1 or have the interval between them filled with soft and unconsolidated earth4 ,all these are the undeniable effects of some great convulsion1 which has shaken the very foundations of the earth2 but which1 far from being a disorder in nature1 is part of a regular system1 essential to the constitution and economy of the globe4 ,the production of the appearances now described1 belongs1 without doubt1 to different periods of time2 and1 where slips intersect one another1 we can often distinguish the less from the more ancient ,they are all1 however1 of a date posterior to that at which the waving and undulated forms of the strata were acquired1 as they do not carry with them any marks of the softness of the rock1 but many of its complete induration4 ,the same phenomenon which is thus exemplified on a great scale in the bowels of the earth1 is often most beautifully exhibited in single specimens of stone1 and is accompanied with this remarkable circumstance1 that the integrity of the stone is not destroyed by the shifts1 whatever wounds had been made in it being healed1 and the parts firmly reunited to one another4#ae ,footnote #ae3 ,,note ,,xi4 #dc4 ,though such marks of violence as have been now enumerated are common in some degree to all the strata1 they abound most among the primary1 and point out these as the part of our globe which has been exposed to the greatest vicissitudes4 ,at their junction with the secondary1 or where they emerge1 as it were1 from under the latter1 phenomena occur1 which mark some of those vicissitudes with astonishing precision2 phenomena of which the nature was first accurately explored1 and the consequences fully deduced1 by the geologist whose system ,i am endeavouring to explain4 ,he observed1 in several instances1 that where the primary schistus rises in beds almost vertical1 it is covered by horizontal layers of secondary sandstone1 which last are penetrated by the irregular tops of the schistus1 and also involve fragments of that rock1 some angular1 others round and smooth1 as if worn by attrition4 ,from this he concluded1 that the primary strata1 after being formed at the bottom of the sea1 in planes nearly horizontal1 were raised1 so as to become almost vertical1 while they were yet covered by the ocean1 and before the secondary strata had begun to be deposited on them4 ,he also argued1 that1 as the fragments of the primary rock1 included in the secondary1 are many of them rounded and worn1 the deposition of the latter must have been separated from the elevation of the former by such an interval of time1 as gave room for the action of waste and decay1 allowing those fragments first to be detached1 and afterwards wrought into a round figure4#af ,footnote #af3 ,,note ,,xii4 #dd4 ,indeed1 the interposition of a breccia between the primary and secondary strata1 in which the fragments1 whether round or angular1 are always of the primary rock1 is a fact so general1 and the quantity of this breccia is often so great1 that it leads to a conclusion more paradoxical than any of the preceding1 but from which1 nevertheless1 it seems very difficult to withhold assent4 ,round gravel1 when in great abundance1 agreeably to a remark already made1 must necessarily be considered as a production peculiar to the beds of rivers1 or the shores of continents1 and as hardly ever formed at great depths under the surface of the sea4 ,it should seem1 then1 that the primary schistus1 after attaining its erect position1 had been raised up to the surface1 where this gravel was formed2 and from thence had been let down again to the depths of the ocean1 where the secondary strata were deposited on it4 ,such alternate elevations and depressions of the bottom of the sea1 however extraordinary they may seem1 will appear to make a part of the system of the mineral kingdom1 from other phenomena hereafter to be described4 #de4 ,on the whole1 therefore1 by comparing the actual position of the strata1 their erectness1 their curvature1 the interruptions of their continuity1 and the transverse stratification of the secondary in respect of the primary1 with the regular and level situation which the same strata must have originally possessed1 we have a complete demonstration of their having been disturbed1 torn asunder1 and moved angularly1 by a force that has1 in general1 been directed from below upwards4 ,in establishing this conclusion1 we have reasoned more from the facts which relate to the angular elevation of the strata1 than from those which relate to their absolute elevation1 or their translation to a greater distance from the centre of the earth4 ,this has been done1 because the appearances1 which respect the absolute lifting up of the strata are more ambiguous than those1 which respect the change of their angular position4 ,the former might be accounted for1 could they be separated from the latter1 in two ways1 viz4 either by the retreat of the sea1 or the raising up of the land2 but the latter can be explained only in one way1 and force us of necessity to acknowledge the existence of an expanding power1 which has acted on the strata with incredible energy1 and has been directed from the centre toward the circumference4 #df4 ,when we are assured of the existence of such a power as this in the mineral regions1 we should argue with singular inconsistency1 if we did not ascribe to it all the other appearances of motion in those regions1 which it is adequate to produce4 ,if nature in her subterraneous abodes is provided with a force that could burst asunder the massy pavement of the globe1 and place the fragments upright upon their edges1 could she not1 by the same effort1 raise them from the greatest depths of the sea1 to the highest elevation of the land8 ,the cause that is adequate to one of these effects is adequate to them both together2 for it is a principle well known in mechanical philosophy1 that the force which produces a parallel motion1 may1 according to the way in which it is applied1 produce also an angular motion1 without any diminution of the former effect4 ,it would1 therefore1 be extremely unphilosophical to suppose1 that any other cause has changed the relative level of the strata1 and the surface of the sea1 than that which has1 in so many cases1 raised the strata from a horizontal to a highly inclined1 or even vertical situation3 it would be to introduce the action of more causes than the phenomena require1 and to forget1 that nature1 whose operations we are endeavouring to trace1 combines the possession of infinite resources with the most economical application of them4 #dg4 ,from all1 therefore1 that relates to the position of the strata1 ,i think ,i am justified in affirming1 that their disturbance and removal from the place of their original formation1 by a force directed from below upwards1 is a fact in the natural history of the earth1 as perfectly ascertained as any thing which is not the subject of immediate observation4 ,as to the power by which this great effect has been produced1 we cannot expect to decide with equal evidence1 but must be contented to pass from what is certain to what is probable4 ,we may1 then1 remark1 that of the forces in nature to which our experience does in any degree extend1 none seems so capable of the effect we would ascribe to it1 as the expansive power of heat2 a power to which no limits can be set1 and one1 which1 on grounds quite independent of the elevation of the strata1 has been already concluded to act with great energy in the subterraneous regions4 ,we have1 indeed1 no other alternative1 but either to adopt this explanation1 or to ascribe the facts in question to some secret and unknown cause1 though we are ignorant of its nature1 and have no evidence of its existence4 ,we are therefore to suppose1 that the power of the same subterraneous heat1 which consolidated and mineralized the strata at the bottom of the sea1 has since raised them up to the height at which they are now placed1 and has given them the various inclinations to the horizon which they are found actually to possess4 #dh4 ,the probability of this hypothesis will appear greatly increased1 when it is considered1 that1 besides those now enumerated1 there are other indications of movement among the bodies of the mineral kingdom1 where effects of heat more characteristic than simple expansion are clearly to be discovered4 ,thus1 on examining the marks of disorder and movement which are found among the strata1 it cannot fail to be observed1 that notwithstanding the fracture and dislocation1 of which they afford so many examples1 there are few empty spaces to be met with among them1 as far as our observation extends4 ,the breaches and separations are numerous1 and distinct2 but they are1 for the most part1 completely filled up with minerals of a kind quite different from the rock on each side of them1 and remarkable for containing no vestiges of stratification4 ,we are thus led to consider the unstratified minerals1 the second of the divisions into which the whole mineral kingdom1 viewed geologically1 ought to be distinguished4 ,these minerals are immediately connected with the disturbance of the strata1 and appear1 in many instances1 to have been the instruments of their elevation4 ,,section ,,ii4 ,,of ,,the ,,phenomena ,,peculiar ,,to ,,unstratified ,,bodies4 #a4 ,metallic ,veins4 #di4 ,,the unstratified minerals exist either in veins1 intersecting the stratified1 or in masses surrounded by them4 ,veins are of various kinds1 and may in general be defined1 separations in the continuity of a rock1 of a determinate width1 but extending indefinitely in length and depth1 and filled with mineral substances1 different from the rock itself4 ,the mineral veins1 strictly so called1 are those filled with crystallized substances1 and containing the metallic ores4 ,that these veins are of a formation subsequent to the hardening and consolidation of the strata which they traverse1 is too obvious to require any proof2 and it is no less clear1 from the crystallized and sparry structure of the substances contained in them1 that these substances must have concreted from a fluid state4 ,now1 that this fluidity was simple1 like that of fusion by heat1 and not compound1 like that of solution in a menstruum1 is inferred from many phenomena4 ,it is inferred from the acknowledged insolubility of the substances that fill the veins1 in any one menstruum whatsoever2 from the total disappearance of the solvent1 if there was any2 from the complete filling up of the vein by the substances which that solvent had deposited2 from the entire absence of all the appearances of horizontal or gradual deposition2 and1 lastly1 from the existence of close cavities1 lined with crystals1 and admitting no egress to any thing but heat4 #ej4 ,to the same effect may be mentioned those groups of crystals composed of substances the most different1 that are united in the same specimen1 all intersecting and mutually impressing one another4 ,these admit of being explained1 on the supposition that they were originally in fusion1 and became solid by the loss of heat2 a cause that acted on them all alike1 and alike impelled them to crystallize3 ,but the appearances of simultaneous crystallization seem incompatible with the nature of deposition from a solvent1 where1 with respect #af different substances1 the effects must take place slowly1 and in succession4 #ea4 ,the metals contained in the veins which we are now treating of1 appear very commonly in the form of an ore1 mineralized by sulphur4 ,their union with this latter substance can be produced1 as we know1 by heat1 but hardly by the way of solution in a menstruum1 and certainly not at all1 if that menstruum is nothing else than water4 ,the metals1 therefore1 when mineralized by sulphur1 give no countenance to the hypothesis of aqueous solution2 and still less do they give any when they are found native1 as it is called1 that is1 malleable1 pure and uncombined with any other substance4 ,the great masses of native iron found in ,siberia and ,south ,america are well known2 and nothing certainly can less resemble the products of a chemical precipitation4 ,gold1 however1 the most perfect of the metals1 is found native most frequently2 the others more rarely1 in proportion nearly to the facility of their combination with sulphur4 ,of all such specimens it may be safely affirmed1 that if they have ever been fluid1 or even soft1 they must have been so by the action of heat2 for1 to suppose that a metal has been precipitated1 pure and uncombined from any menstruum1 is to trespass against all analogy1 and to maintain a physical impossibility4 ,but it is certain1 that many of the native metals have once been in a state of softness1 because they bear on them impressions which they could not have received but when they were soft4 ,thus1 gold is often impressed by quartz and other stones1 which still adhere to it1 or are involved in it4 ,specimens of quartz1 containing gold and silver shooting through them1 with the most beautiful and varied ramifications1 are every where to be met with in the cabinets of the curious2 and contain1 in their structure1 the clearest proof1 that the metal and the quartz have been both soft1 and have crystallized together4 ,by the compactness1 also1 of the body which they form1 they show1 that when they acquired solidity1 it was by the concretion of the whole mass1 and not by such partial concretion as takes place when a solvent is separated from substances which it held in solution4 #eb4 ,native copper is very abundant2 and some specimens of it have been found crystallized4 ,here the crystallization of the metal is a proof that it has passed from a fluid to a solid state2 and its purity is a proof that it did not make that transition by being precipitated from a menstruum4 #ec4 ,again1 pieces of native manganese have been found possessing so exactly the characters peculiar to that metal when reduced in our furnaces1 that it is impossible to consider them as deriving their figure and solidity from any cause but fusion4 ,the ingenious author who describes these specimens1 ,la ,peyrouse1 was so forcibly struck with this resemblance1 that he immediately drew the same conclusion from it which is drawn here1 attributing the only difference1 which he remarked between the native and the artificial regulus1 to the different energy with which the same agent works when employed by nature and by art4#ag ,footnote #ag3 ,theory of the ,earth1 vol4 i4 p4 #fh4 ,journal de ,phys4 ,janvier1 #aghf4 #ed4 ,all these appearances conspire to prove1 that the materials which fill the mineral veins were melted by heat1 and forcibly injected1 in that state1 into the clefts and fissures of the strata4 ,these fissures we must conceive to have arisen1 not merely from the shrinking of the strata while they acquired hardness and solidity1 but from the violence done to them1 when they were heaved up and elevated in the manner which has already been explained4#ah ,footnote #ah3 ,,note ,,xiii4 #ee4 ,when these suppositions are once admitted1 the other leading facts in the history of metallic veins will be readily accounted for4 ,thus1 for instance1 it is evident to what we must ascribe the fragments of the surrounding rock that are often found immersed in the veins1 and encompassed on all sides by crystallized substances4 ,these fragments being no doubt detached by the concussion1 which at once tore asunder and elevated the strata1 were sustained by the melted matter that flowed at the same time upward through the vein4 ,large masses of rock are often found in this manner completely insulated2 one of these1 which ,m4 ,de ,luc has described with great accuracy1 is no less than a vast segment of a mountain4#ai ,footnote #ai3 ,lettres ,physiques1 c4 tom4 iii4 ,p4 #cfa4 #ef4 ,the immense violence which has accompanied the formation of mineral veins1 is particularly marked by the slips and shifts of the strata on each side of them all tending to show what mighty changes have taken place in those regions1 which our imagination erroneously paints as the abode of everlasting silence and rest4 ,this shifting of the strata is best observed1 where the veins make a transverse section of beds of rock1 considerably inclined to the horizon4 ,there it is common to see the beds on one side of the vein slipped along from the corresponding beds on the other side1 and removed sometimes in a horizontal1 sometimes in an oblique direction4 ,in this way1 not only the strata are shifted1 but veins1 which intersect one another1 are also shifted themselves4 ,they are heaved1 as it is called in the significant language of the miners1 and forced out of their direction4 ,it is impossible1 in such a case1 but to connect in the mind the formation of the vein1 and the production of the slips which accompany it1 and to regard them as parts of the same phenomenon4 #eg4 ,where these slips are horizontal1 and exhibit great bodies of strata carried from their place1 while the parts of the transferred mass remain undisturbed relatively to one another1 they furnish a dear proof1 that this change of plaice has not arisen from the falling in of the roofs of caverns1 as some geologists suppose4 ,the horizontal direction1 and the regularity of the movement1 are incompatible with the action of such a cause as this2 and indeed it is highly interesting to remark1 in the midst of the signs of disturbance which prevail in the bowels of the earth1 that there reigns a certain symmetry and order1 which indicate the action of a force of incredible magnitude1 but slow and gradual in its effects4 ,the parts of the mass moved are undisturbed relatively to one another2 what has been broken has been cemented2 the breaches of continuity have been filled up and healed2 and every where we see the operation of a cause that could unite as well as separate4 ,the twofold action of heat to expand and to melt1 could scarce be pointed out more clearly by any system of appearances4 #eh4 ,as a long period was no doubt required for the elevation of the strata1 the rents made in them are not all of the same date1 nor the veins all of the same formation4 ,this is clear in the case of one vein producing a shift or slip in another2 for the vein which forces the other out of its place1 and preserves its own direction1 is evidently the more recent of the two1 and must have had its materials in a state of activity1 when those of the other were inert4 ,sometimes1 also1 at the intersection of two veins1 we may trace the current of the materials of the one1 across those of the other2 and here1 of consequence1 the relative antiquity is determined just as in the former instance4 #ei4 ,the want of any appearance of stratification in mineral veins has already been taken notice of4 ,there is1 however1 to be observed1 in many instances1 a tendency to a regular arrangement of the substances contained in them2 those of the same kind forming coats parallel to the sides of the vein1 and nearly of an equal thickness4 ,this phenomenon is considered as one of the strongest arguments in favour of the ,neptunian system1 but has nothing in it1 in the least incompatible with that theory which ascribes the formation of veins to the action of subterraneous heat4 ,when melted matter from the mineral regions was thrown up into the veins1 that which was nearest to the sides would soonest lose its heat4 ,the similar substances1 also1 would unite while this process was going forward1 and would crystallize1 as in other cases of congelation1 from the sides toward the interior4 ,there is the more reason for supposing this to have been the case1 that the same sort of coating is often observed on the inside of close cavities1 which are1 nevertheless1 so constructed1 as to afford a demonstration that no chemical solvent was ever included in them1 7 #gd47 ,some veins1 it must also be considered1 may have been filled by successive injections of melted matter1 and this would naturally give rise to a variety of separate incrustations4#bj ,footnote #bj3 ,see some farther remarks on this subject at ,,note ,,xiii4 #fj4 ,in the view now given of metallic veins1 they have been considered as traversing only the stratified parts of the globe4 ,they do1 however1 occasionally intersect the unstratified parts1 particularly the granite1 the same vein often continuing its course across rocks of both kinds1 without suffering any material change2 and1 if we have hitherto paid no attention to this circumstance1 it is because the order pursued in this essay required1 that the relation of the veins to stratified bodies should be first treated of4 ,besides1 the facts in the natural history of veins1 whether contained in stratified or unstratified rocks1 are so nearly alike1 that in a general view of geology1 they do not require to be distinguished4 ,it is material to remark1 that1 though metallic veins are found indiscriminately in all the different kinds of rock1 whether stratified or otherwise1 they are most abundant in the class of primary schisti4 ,all the countries most remarkable for their mines1 and the mountains distinguished by the name of metalliferous1 are primary1 and the instance of ,derbyshire is perhaps the most considerable exception to this rule that is known4 ,this preference1 which the metals appear to give to the primary strata1 is very consistent with ,dr ,hutton's theory1 which represents the rocks of that order as being most changed from their original position1 and those on which the disturbing forces of the subterraneous regions have acted most frequently1 and with greatest energy4 ,the primary strata are the lowest1 also1 and have the most direct communication with those regions from which the mineral veins derive all their riches4 #b4 ,of ,whinstone4 #fa4 ,beside the veins filled with spar1 and containing the metallic ores1 the strata are intersected by veins of whinstone1 porphyry1 and granite1 the characters of which are next to be examined4 ,the term whin1 or whinstone1 with ,dr4 ,hutton1 like the word trap1 with the ,german mineralogists1 denotes a class of stones1 comprehending several distinct species1 or at least varieties4 ,the common basalt1 the wacken1 mullen1 and crag of ,kirwan1 the grnstein of ,werner1 and the amygdaloid1 are comprehended under the name of whin4 ,all these stones have a tendency to a spathose structure1 and discover at least the rudiments of crystallization4 ,they are1 at the same time1 without any mark of stratification in their internal texture1 as they are also1 for the most part1 in their outward configuration2 and1 as the different species here enumerated compose1 not unfrequently1 parts of the same continuous rock1 the change from one to another being made through a series of insensible gradations1 they may safely be regarded by the geologist as belonging to the same genus4 #fb4 ,whin1 though not stratified1 exists in two different ways1 that is1 either in veins1 7called in ,scotland dykes17 traversing the strata like the veins already described1 or in irregular masses1 incumbent on the strata1 and sometimes interposed between them4 ,in both these forms1 whinstone has nearly the same characters1 and bears1 in all its varieties1 a most striking resemblance to the lavas which have actually flowed from volcanoes on the surface of the earth4 ,this resemblance is so great1 that the two substances have been often mistaken for one another2 and many rocks1 which have been pronounced to be the remains of extinguished volcanoes1 by mineralogists of no inconsiderable name1 have been found1 on closer examination1 to be nothing else than masses or veins of whinstone4 ,this latter stone is indeed only to be distinguished from the former1 by a careful examination of the internal characters of both2 and chiefly from this circumstance1 that whinstone often contains calcareous spar and zeolite1 whereas neither of these substances is found in such lavas1 as are certainly known to have been thrown out by volcanic explosions4 ,now1 from these circumstances of affinity between lava and whinstone1 on the one hand1 and of diversity on the other1 as the formation of the one is known1 it should seem that some probable conclusion may be drawn concerning the formation of the other4 ,the affinity in question is constant and essential2 the difference variable and accidental2 and this naturally leads to suspect1 that the two stones have the same origin2 and that1 as lava is certainly a production of fire1 so probably is whinstone4 #fc4 ,but1 in order to see whether this hypothesis will explain the diversity of the two substances1 without which it will not be entitled to much attention1 we must remark1 that the presence of carbonate of lime in a body that has been fused1 argues1 agreeably to the principles formerly explained1 that the fusion was brought about under a great compressing force1 that is to say1 deep in the bowels of the earth1 or in the great laboratory of the mineral regions4 ,we are1 therefore1 to suppose that the fusion of the whin was performed in those regions1 where the compression was sufficient to preserve the carbonic gas in union with the calcareous earth1 so that these two substances melted together1 and1 on cooling1 crystallized into spar4 ,in the lavas1 again1 thrown out by volcanic eruption1 the fusion1 as we know1 wherever it may begin1 continues in the open air1 where the pressure is only that of the atmosphere3 the calcareous earth1 which1 therefore1 may have been1 in the form of a carbonate1 among the materials of this lava1 must be converted into quicklime1 and become infusible2 hence the want of calcareous spar in lavas that have flowed at the surface4 ,thus1 whinstone is to be accounted a subterraneous1 or unerupted lava2 and our theory has the advantage of explaining both the affinity and the difference between these stony bodies1 without the introduction of any new hypothesis4 ,in the ,neptunian system1 the affinity of whinstone and lava is a paradox which admits of no solution4 #fd4 ,the columnar structure sometimes found in that species of whinstone called basaltes1 is a fact which has given rise to much discussion2 and it must be confessed1 that though one of the most striking and peculiar characters of this fossil1 it is not that which gives the clearest and most direct information concerning its origin4 ,one circumstance1 however1 very much in favour of the opinion that basaltic rocks owe their formation to fire1 is1 that the columnar form is sometimes assumed by the lava actually erupted from volcanoes4 ,now1 it is certainly of no small importance1 to have the synthetic argument on our side1 and to know1 that basaltic columns can be produced by fire2 though1 no doubt1 to give absolute certainty to our conclusion1 it would be necessary to show1 that there are in nature no other means but this by which these columns can be formed4 ,this sort of evidence is hardly to be looked for2 but since the power of fusion1 to produce the phenomena in question1 is perfectly established1 and since the production of the same phenomena in the humid way is a mere hypothesis1 if there be the least reason to suspect the action of subterraneous heat as one of the causes of mineralization1 every maxim of sound philosophy requires that the basaltic structure1 in all cases1 should be ascribed to it4 #fe4 ,the ,neptunists will no doubt allege1 with ,,bergman1 that1 in the drying of starch1 clay1 and a few other substances1 something analogous to basaltic columns is produced4 ,here1 however1 a most important difference is to be remarked1 corresponding very exactly to one of the characters which we have all along observed to distinguish the products of aqueous1 from those of igneous consolidation4 ,the columns formed by the substances just mentioned1 are distant from one another3 they are separated by fissures which widen from the bottom to the top1 and which arise from the shrinking and drying of the mass4 ,in the basaltic columns1 no such openings1 nor vacuity of any kind is found2 the pillars are in contact1 and1 though perfectly distinct1 are so close1 that the sharp edge of a wedge can hardly be introduced between them4 ,this is a great peculiarity in the basaltic structure1 and is strongly expressive of this fact1 that the mass was all fluid together1 and that its parts took their new arrangement1 not in consequence of the separation of a fluid from a solid part1 by which great shrinking and much empty space might be produced2 but in consequence of a cause which1 like refrigeration1 acted equally on all the parts of the mass1 and preserved their absolute contact after their fluidity had ceased4 #ff4 ,a mark of fusion1 or at least of the operation of heat1 which whinstone possesses in common with many other minerals1 is its being penetrated by pyrites1 a substance1 as has been already remarked1 that is of all others most exclusively the production of fire4 ,another mark of fusion1 more distinctive of whin1 is1 that both in veins and in masses it sometimes includes pieces of sandstone1 or of the other contiguous strata1 completely insulated1 and having the appearance of fragments of rock1 floating in a fluid sufficiently dense and ponderous to sustain their weight4 ,though these fragments have been too refractory to be reduced into fusion themselves1 they have not remained entirely unchanged1 but are1 in general1 extremely indurated1 in comparison of the rock from which they appear to have been detached4 #fg4 ,similar instances of extraordinary induration are observed in the parts of the strata in contact with whinstone1 whether they form the sides of the veins1 or the floors1 and roofs of the masses into which the whinstone is distributed4 ,the strata whether sandy or argillaceous1 in such situations1 are usually extremely hard and consolidated2 the former in particular lose their granulated texture1 and are sometimes converted into perfect jasper4 ,this interesting remark was first made by ,dr ,hutton1 and the truth of it has been verified by a great number of subsequent observations4 #fh4 ,to the same excellent geologist we are indebted for the knowledge of an analogous fact1 attendant on the passage of whinstone veins through coal strata4 ,as the beds of stone where they are in contact with veins of whin1 seem to acquire additional induration1 so those of coal1 in like circumstances1 are frequently found to have lost their fusibility1 and to be reduced nearly to the condition of coke1 or of charcoal4 ,the existence of coal of this kind has been already mentioned1 and considered as a proof of the operation of subterraneous heat4 ,in the instances here referred to1 that is1 where the charring of the coal is limited to those parts of the strata which are in contact with the whin1 or in its immediate vicinity1 the heat is pointed out as residing in the vein2 and this is to be accounted for only on the supposition of the melted whin1 at a period subsequent to the consolidation of the coal1 having flowed through the openings of the strata4 ,the heat has been powerful enough1 in many cases1 to drive off the bituminous matter of the coal1 and to force it into colder and more distant parts4 ,few facts1 in the history of fossils1 are more remarkable than this1 and none more directly assimilates the operations of the mineral regions1 with those that take place at the surface of the earth4 #fi4 ,again1 the disturbance of the strata1 wherever veins of whinstone abound1 if not a direct proof of the original fluidity of the whinstone1 is a clear indication of the violence with which it was introduced into its place4 ,this disturbance of the position of the strata1 by shifting1 unusual elevation1 and other irregularities1 where they are intersected by whinstone veins1 is a fact so well known to miners1 that when they meet with any sudden change in the lying of the metals1 they are wont to foretell their approach to masses1 or veins of unstratified matter2 and1 in their figurative language1 point them out as the causes of the confusion with which they are so generally accompanied4#ba ,the mineral veins likewise1 as well as the strata1 are often heaved and shifted by the veins of whinstone4 ,footnote #ba3 ,a ,trouble is the name which the colliers in this country give to a vein of whinstone4 #gj4 ,whinstone of every species is found frequently interposed in tabular masses1 between beds of stratified rocks2 and it then adds to the indications of its igneous origin1 already enumerated1 some others that are peculiar to it when in this situation4 ,in such instances1 it is not uncommon to find the strata in some places1 contiguous to the whin1 elevated1 and bent with their concavity upward1 so that they appear clearly to have been acted on by a force that proceeded from below1 at the same time that they were softened1 and rendered in some degree flexible3 it is needless to remark1 that these effects can be explained by nothing but the fusion of the whin2 and that the great force with which it was impelled against the strata1 could be produced by no cause but heat1 acting in the manner that is here supposed4 #ga4 ,again1 if it be true that the masses of whin1 thus interposed among the strata1 were introduced there1 after the formation of the latter1 we might expect to find1 at least in many instances1 that the beds on which the whinstone rests1 and those by which it is covered1 are exactly alike4 ,if these beds were once contiguous1 and have been only heaved up and separated by the irruption of a fluid mass of subterraneous lava1 their identity should still be recognised4 ,now1 this is precisely what is observed2 it is known to hold in a vast number of instances1 and is strikingly exemplified in the rock of ,salisbury ,crag1 near ,edinburgh4 ,this similarity of the strata that cover the masses of whinstone1 to those that serve as the base on which they rest1 and again the dissimilitude of both to the interposed mass1 are facts which ,i think can hardly receive any explanation1 on the principles of the ,neptunian theory4 ,if these rocks1 both stratified and unstratified1 are to be regarded as productions of the sea1 the circumstances would require to be pointed out1 which have determined the whinstone1 and the beds that are all round it1 to be so extremely unlike in their structure1 though formed at the same time1 and in the immediate vicinity of one another2 as also those circumstances1 on the other hand1 which determined the stratified deposits above and below the whinstone1 to be precisely the same1 though the times of their formation must have been very different4 ,the homogeneous substances1 thus1 placed at a distance1 and the heterogeneous brought so closely together1 are phenomena equally unaccountable1 in a theory that ascribes their origin to the operation of the same element1 and that necessarily dates their formation according to the order in which they lie1 one above another4 #gb4 ,if1 indeed1 in these instances1 the gradation were insensible1 as some have asserted it to be1 between the strata and the interposed mass1 so that it was impossible to point out the line where the one ended and the other began1 whatever difficulties we might perceive in the ,neptunian theory1 we should find it hard to substitute a better in its room4 ,but the truth seems to be1 that1 in the cases we are now treating of1 no such gradation exists2 and that1 though where the two kinds of rock come into contact a change is often observed1 by the strata having acquired an additional degree of induration1 yet the line of separation is well defined1 and can be precisely ascertained4 ,this at least is certain1 that innumerable specimens1 exhibiting such lines of separation1 are to be met with2 and wherever care has been taken to obtain a fresh fracture of the stone1 and to remove the effects of accidental causes1 even where the two rocks are most firmly united1 and most closely assimilated1 ,i am persuaded that no uncertainty has ever remained as to the line of their separation4 ,for these reasons1 it seems probable that the gradual transition of basaltes into the adjoining strata1 is in all cases imaginary1 and is1 in truth1 a mere illusion1 proceeding from hasty and inaccurate observation4 #gc4 ,another remarkable fact in the natural history of the whinstone rocks1 remains yet to be mentioned1 and with it ,i shall conclude the argument1 as far as these rocks are concerned4 ,some of the species of whinstone are the common matrices of agates and chalcedonies1 which lie inclosed in them in the form of round nodules4 ,the original fluidity of these nodules is evinced by their figured1 and sometimes crystallized structure1 and indeed is so generally admitted1 that the only question concerning them is1 whether this fluidity was the effect of heat or of solution4 ,to answer this question1 ,dr ,hutton observes1 that the formation of the concentric coats1 of which the agate is usually composed1 has evidently proceeded from the circumference toward the centre1 the exterior coats always impressing the interior1 but never the reverse4 ,the same thing also follows from this other fact1 that when there is any vacuity within the agate1 it is usually at the centre1 and there too are found the regular crystals1 when any such have been formed4 ,it therefore appears certain1 that the progress of consolidation has been from the circumference inwards1 and that the outward coats of the agate were the first to acquire solidity and hardness4 #gd4 ,now1 it must be considered that these coats are highly consolidated2 that they are of very pure siliceous matter1 and are utterly impervious to every substance which we know of1 except light and heat4 ,it is plain1 therefore1 that whatever at any time1 during the progress of consolidation1 was contained within the coats already formed1 must have remained there as long as the agate was entire1 without the least possibility of escape4 ,but nothing is found within the coats of the agate save its own substance2 therefore1 no extraneous substance1 that is to say no solvent1 was ever included within them4 ,the fluidity of the agate was therefore simple1 and unassisted by any menstruum4 ,in this argument1 nothing appears to me wanting1 that is necessary to the perfection of a physical1 ,i had almost said of a mathematical1 demonstration4 ,it seems1 indeed1 to be impossible that the igneous origin of fossils could be recorded in plainer language1 than by the phenomenon which has just been described4 #ge4 ,the examination of particular specimens of agates and chalcedonies1 affords many more arguments of the same kind1 which ,dr ,hutton used to deduce with an acuteness and vivacity1 which his friends have often listened to with great admiration and delight4#bb ,these1 however1 must be passed over at present2 and ,i have only further to remark1 that a series of the most interesting experiments1 instituted by ,sir ,,james ,,hall1 and published in the ,transactions of the ,royal ,society of ,edinburgh1#bc has removed the only remaining objection that could be urged against the igneous origin of whinstone4 ,this objection is founded on the common observation1 that when a piece of whinstone or basaltes is actually melted in a crucible1 on cooling1 it becomes glass1 and loses its original character entirely2 and from thence it was concluded1 that this character had not been originally produced by fusion4 ,the experiments above mentioned1 however1 have shown1 in the most satisfactory manner1 that melted whin1 by regulated or by slow cooling1 is prevented from assuming the appearance of glass1 and becomes a stony substance1 hardly to be distinguished from whinstone or lava4 ,footnote #bb3 ,,note ,,xvi4 ,footnote #bc3 vol4 v4 p4 #dc4 ,the experiments of another ingenious chemist1 ,dr ,,kennedy1 have shown1 that whinstone contains mineral alkali1 by which1 of course1 its fusion must have been assisted4#bd ,dr ,hutton used to ascribe its fusibility1 in a great measure at least1 to the quantity of iron contained in it3 both these causes have no doubt united to render it more easily melted than the ordinary materials of the strata4 ,footnote #bd3 ,trans4 ,r4 ,s4 ,edin4 vol4 v4 p4 #he4 #gf4 ,in a word1 therefore1 to conceive aright the origin of that class of unstratified rocks1 distinguished by the name of whinstone1 we must suppose1 that long after the consolidation of the strata1 and during the time of their elevation1 the materials of the former were melted by the force of subterraneous heat1 and injected among the rents and fissures of the rocks already formed4 ,in this manner were produced the veins or dikes of whinstone2 and1 where circumstances allowed the stream of melted matter to diffuse itself more widely1 tabular masses were formed1 which were afterwards raised up1 together with the surrounding strata1 above the level of the sea1 and have been since laid open by the operation of those causes that continually change and waste the surface of the land4 ,these unstratified rocks are not1 however1 all the work of the same period2 they differ evidently in the date of their formation1 and it is not unusual1 to find tabular masses of one species of whin1 intersected by veins of another species4 ,indeed1 of all the fossil bodies which compose the present land1 the veins of whin appear to be the most recently consolidated4#be ,footnote #be3 ,,note ,,xiv4 ,porphyry may so properly be regarded as a variety of whin1 distinguished only by involving crystallized feldspar1 that1 in a geological sketch like the present1 it is hardly entitled to a separate article4 ,like the other kinds of whin1 it exists both in veins and in tabular masses1 having1 no doubt1 an origin similar to that which has just been described4 ,porphyry1 however1 has the peculiarity of being rarely found in any but the primary strata2 it seems to be the whinstone of the old world1 or at least that which is of the highest antiquity in the present4 ,it no where1 ,i believe1 assumes a columnar1 or basaltic appearance1 of any regularity2 but this is also true of many other varieties of whin1 of all1 indeed1 except the most compact and homogeneous4 ,these differences are not so considerable as to require our entering into any particular detail concerning the natural history of this fossil4 #c4 ,granite4 #gg4 ,the term ,granite is used by ,dr ,hutton to signify an aggregate stone1 in which quartz1 feldspar1 and mica are found distinct from one another1 and not disposed in layers4 ,the addition of hornblende1 schorl1 or garnet1 to the three ingredients just mentioned1 is not understood to alter the genus of the stone1 but only to constitute a specific difference1 which it is the business of lithology to mark by some appropriate character1 annexed to the generic name of granite4 ,the fossil now defined exists1 like whinstone and porphyry1 both in masses and in veins1 though most frequently in the former4 ,it is like them unstratified in its texture1 and is regarded here1 as being also unstratified in its outward structure4#bf ,one ingredient which is essential to granite1 namely1 quartz1 is not contained in whinstone2 and this circumstance serves to distinguish these genera from one another1 though1 in other respects1 they seem to be united by a chain of insensible gradations1 from the most homogeneous basaltes1 to granite the most highly crystallized4 ,footnote #bf3 ,those rocks that consist of the ingredients here enumerated1 if they have at the same time a schistose texture1 or a disposition into layers1 are properly distinguished from granite1 and called ,gneiss1 or ,granitic ,schistus4 ,but it has been questioned whether a stone does not exist composed of these ingredients1 and destitute of a schistose texture1 but yet divided into large beds1 visible in its external form4 ,dr ,hutton supposes such a stone not to exist1 or at least not to constitute any such proportion of the mineral kingdom1 as to entitle it to particular consideration1 in the general speculations of geology4 ,whether this supposition is perfectly correct1 may require to be farther considered3 this1 however1 is certain1 that a rock1 in all respects conformable to it1 composes a great proportion of what are usually called the granite mountains4 ,see ,,note ,,xv4 #gh4 ,granite1 it has been just said1 exists most commonly in masses2 and these masses are rarely1 if ever1 incumbent on any other rock3 they are the basis on which others rest1 and seem1 for the most part1 to rise up from under the ancient1 or primary strata4 ,the granite1 therefore1 wherever it is found1 is inferior to every other rock2 and as it also composes many of the greatest mountains1 it has the peculiarity of being elevated the highest into the atmosphere1 and sunk the deepest under the surface1 of all the mineral substances with which we are acquainted4 ,notwithstanding the circumstance of not being alternated with stratified bodies1 which constitutes a remarkable difference between granite and whinstone1 the affinity of these fossils is such as to make the similarity of their origin by no means improbable4 ,accordingly1 in ,dr ,hutton's theory1 granite is regarded as a stone of more recent formation than the strata incumbent on it2 as a substance which has been melted by heat1 and which1 when forced up from the mineral regions1 has elevated the strata at the same time4 #gi4 ,that granite has undergone a change from a fluid to a solid state1 is evinced from the crystallized structure in which some of its component parts are usually found4 ,this crystallization is particularly to be remarked of the feldspar1 and also of the schorl1 where there is any admixture of that substance1 whether in slender spicul1 or in larger masses4 ,the quartz itself is in some cases crystallized1 and is so1 perhaps1 more frequently than is generally supposed4 ,the fluidity of granite1 in some former period of its existence1 is so evident from this1 as to make it appear singular that it should ever have been considered as a fossil that had remained always the same1 and one1 into the origin of which it was needless to inquire4 ,if the regular forms of crystallization are not to be received as proofs of the substance to which they belong having passed from a fluid to a solid state1 neither are the figures of shells and of other supposed petrifactions1 to be taken as indications of a passage from the animal to the mineral kingdom2 so that there is an end of all geological theories1 and of all reasonings concerning the ancient condition of the globe4 ,to an argument which strikes equally at the root of all theories1 it belongs not to this1 in particular1 to make any reply4 #hj4 ,we shall1 therefore1 consider it as admitted1 that the materials of the granite were originally fluid2 and1 in addition to this1 we think it can easily be proved1 that this fluidity was not that of the elements taken separately1 but of the entire mass4 ,this last conclusion follows1 from the structure of those specimens1 where one of the substances is impressed by the forms which are peculiar to another4 ,thus1 in the ,portsoy granite1#bg which ,dr ,hutton has so minutely described1 the quartz is impressed by the rhomboidal crystals of the feldspar1 and the stone thus formed is compact and highly consolidated4 ,hence1 this granite is not a congeries of parts1 which1 after being separately formed1 were somehow brought together and agglutinated2 but it is certain that the quartz1 at least1 was fluid when it was moulded on the feldspar4 ,in other granites1 the impressions of the substances on one another are observed in a different order1 and the quartz gives its form to the feldspar4 ,this1 however1 is more unusual2 the quartz is commonly the substance which has received the impressions of all the rest2 and the spicul of schorl often shoot both across it and the feldspar4 ,footnote #bg3 ,theory of the ,earth1 vol4 i4 p4 #ajd4 ,the ingredients of granite were therefore fluid when mixed1 or at least when in contact with one another4 ,now1 this fluidity was not the effect of solution in a menstruum2 for1 in that case1 one kind of crystal ought not to impress another1 but each of them should have its own peculiar shape4 #ha4 ,the perfect consolidation of many granites1 furnishes an argument to the same effect4 ,for1 agreeably to what was already observed1 in treating of the strata1 a substance1 when crystallizing1 or passing from a fluid to a solid state1 cannot be free from porosity1 much less fill up completely a space of a given form1 if1 at the same time1 any solvent is separated from it2 because the solvent so separated would still occupy a certain space1 and1 when removed by evaporation or otherwise1 would leave that space empty4 ,the perfect adjustment1 therefore1 of the shape of one set of crystallizing bodies1 to the shape of another set1 as in the ,portsoy granite1 and their consolidation into one mass1 is as strong a proof as could be desired1 that they crystallized from a state of simple fluidity1 such as1 of all known causes1 heat alone is able to produce4 #hb4 ,this conclusion1 however1 does not rest on a single class of facts4 ,it has been observed in many instances1 that where granite and stratified rocks1 such as primary schistus1 are in contact1 the latter are penetrated by veins of the former1 which traverse them in various directions4 ,these veins are of different dimensions1 some being of the breadth of several yards1 others of a few inches1 or even tenths of an inch2 they diminish as they recede from the main body of the granite1 to which they are always firmly united1 constituting1 indeed1 a part of the same continued rock4 ,these phenomena1 which were first distinctly observed by ,dr ,hutton1 are of great importance in geology1 and afford a clear solution of the two chief questions concerning the relation between granite and schistus4 ,as every vein must be of a date posterior to the body in which it is contained1 it follows1 that the schistus was not super-imposed on the granite1 after the formation of this last4 ,if it be argued1 that these veins1 though posterior to the schisti1 are also posterior to the granite1 and were formed by the infiltration of water in which the granite was dissolved or suspended2 it may be replied1 #amo1 ,that the power of water to dissolve granite1 is a postulatum of the same kind that we have so often1 and for such good reason1 refused to concede2 and1 #b;do1 ,that in many instances the veins proceed from the main body of the granite upwards into the schistus2 so that they are in planes much elevated in respect of the horizon1 and have a direction quite opposite to that which the hypothesis of infiltration requires4 ,it remains certain1 therefore1 that the whole mass of granite1 and the veins proceeding from it1 are coeval1 and both of later formation than the strata4 ,now1 this being established1 and the fluidity of the veins1 when they penetrated into the schistus1 being obvious1 it necessarily follows1 that the whole granite mass was also fluid at the same time4 ,but this can have been brought about only by subterraneous heat1 which also impelled the melted matter against the superincumbent strata1 with such force as to raise them from their place1 and to give them that highly inclined position in which they are still supported by the granite1 after its fluidity has ceased4 ,thus a conclusion1 rendered probable by the crystallization of granite1 is established beyond all contradiction by the phenomena of granitic veins4#bh ,footnote #bh3 ,,note ,,xv4 #hc4 ,with the granite1 we shall consider the proof of the igneous origin of all mineral substances as completed4 ,these substances1 therefore1 whether stratified or unstratified1 owe their consolidation to the same cause1 though acting with different degrees of energy4 ,the stratified have been in general only softened or penetrated by melted matter1 whereas the unstratified have been reduced into perfect fusion4 #hd4 ,in this general conclusion we may distinguish two parts1 which1 in their degree of certainty1 differ perhaps somewhat from one another4 ,the first of these1 and that which stands highest in point of evidence1 consists of two propositions2 namely1 that the fluidity which preceded the consolidation of mineral substances was ,,simple1 that is1 it did not arise from the combination of these substances with any solvent2 and1 next1 that after consolidation1 these bodies have been raised up by an expansive force acting from below1 and have by that means been brought into their present situation4 ,these two propositions seem to me to be supported by all the evidence that is necessary to constitute the most perfect demonstration4 #he4 ,the other part of the general conclusion1 that fire1 or more properly heat1 was the cause of the fluidity of these mineral bodies1 and also of their subsequent elevation1 is not perhaps to be considered as a truth so fully demonstrated as the two preceding propositions2 it is1 no doubt1 a matter of ,,theory2 or a portion of one of those invisible chains by which men seek to connect in the mind the state of nature that is present1 with the states of it that are past2 and participates of that uncertainty from which our reasonings concerning such causes as are not direct objects of perception1 are hardly ever exempted4 ,that it participates of this uncertainty in a very slight degree1 will1 however1 be admitted1 when it is considered that the cause assigned has been proved sufficient for the effect2 that the same is not true of any other known cause2 and that this theory accounts1 with singular simplicity and precision1 for a system of facts so various and complex1 as that which is presented by the natural history of the globe4 #hf4 ,neither can it be said that the existence of subterraneous heat is a principle assumed without any evidence1 but that of the geological facts which it is intended to explain3 on the contrary1 it is proved by phenomena within the circle of ordinary experience1 namely1 those of hot springs1 volcanoes1 and earthquakes4 ,these leave no doubt of the existence of heat1 and of a moving and expansive power1 in the bowels of the earth2 so that the only questions are1 at what depth is this power lodged8 to what extent1 and with what intensity1 does it act8 ,that it is lodged at a very considerable depth1 is rendered probable by the permanency of some of the preceding phenomena3 from the earliest times many fountains have retained their heat to the present day2 and volcanoes1 though they become extinguished at length1 have a very long period allotted for their duration4 ,the cause of earthquakes is certainly a force that resides very deep under the surface1 otherwise the extent of the concussion could not be such as has been observed in many instances4 #hg4 ,the intensity of volcanic fire1 is another circumstance that favours the opinion of its being seated deep under the surface4 ,that this intensity is considerable1 is certain from the experiments made by ,sir ,james ,hall on the fusibility of whinstone and lava2 from which it appears1 that the lowest temperature in which either of these stones melt1 is about #hj of ,wedgewood's pyrometer4 ,some mineralogists have indeed affirmed1 that lava is melted1 not by the intensity of the heat applied to it1 but in consequence of a certain combination formed between it and bituminous substances1 in a manner which they do not attempt to explain1 and which has indeed no analogy to any thing that is known4 ,that a hypothesis1 formed in such direct opposition to the most obvious principles of inductive reasoning1 should have been imagined by a philosopher who had examined the phenomena of ,etna and ,vesuvius with much attention1 and described them with great accuracy and truth1 is more wonderful than that it should have been adopted by mineralogists1 whose views of nature may have been confined within a cabinet or a laboratory4 ,it is1 however1 a hypothesis1 which1 having never had any support but from other hypotheses1 hardly merited the direct refutation that it has received from the experiments just mentioned4 #hh4 ,but1 if the intensity of volcanic heat be such as is here stated1 it will be found very difficult to account for a fire of such activity1 and of such long continuance in the same spot1 by any decomposition of mineral substances near the surface4 ,in the place where this combustion is supposed to exist1 it must be remembered1 that there is no fresh supply of materials to replace those that have been consumed1 and that1 therefore1 the original accumulation of these materials in one spot1 must have been very unlike any thing that has ever been observed concerning the disposition of minerals in the bowels of the earth4 #hi4 ,if1 on the other hand1 we ascribe the phenomena of volcanoes to the central heat1 the account that may be given of them is simple1 and consistent with itself4 ,according to all the appearances from which the existence of such heat has been inferred above1 it is of a nature so far different from ordinary fire1 that it may require no circulation of air1 and no supply of combustible materials to support it4 ,it is not accompanied with inflammation or combustion1 the great pressure preventing any separation of parts in the substances on which it acts1 and the absence of that elastic fluid without which heat seems to have no power to decompose bodies1 even the most combustible1 contributing to the unalterable nature of all the substances in the mineral regions4 ,there1 of consequence1 the only effects of heat are fusion and expansion2 and that which forms the nucleus of the globe may therefore be a fluid mass1 melted1 but unchanged by the action of heat4 #ij4 ,if1 from the confines of this nucleus1 we conceive certain fissures and openings to traverse the solid crust1 and to issue at the surface of the earth1 the vapours ascending through these may in time heat the sides of the tubes through which they pass to a vast distance from the lower extremities4 ,it is1 indeed1 difficult to fix the limit to which this distance may extend1 on account of the great difference between the rate at which heat moves when it has a fluid for its vehicle1 and when it is left to make its way alone through a solid body4 ,in the present case1 the supply of heat is rapid1 as being made by a vapour ascending through a tube of solid rock2 and the dissipation of it slow1 as arising from its transmission through the rock4 ,the waste of heat is therefore small1 compared with the supply1 and grows smaller at every given point1 the longer the stream of heated vapour has continued to flow4 ,such a stream1 therefore1 though it may at first be condensed within a small distance of its source1 will in time reach higher and higher1 and may at last be able to carry its heat to an immense distance from the place of its original derivation4 ,thus1 it is easy to conceive1 that vapours from the mineral regions may convey their heat to reservoirs of water near the surface of the earth1 and may in that manner produce hot springs1 and even boiling fountains1 like those of ,rycum and ,geyser4 #ia4 ,when1 instead of a heated vapour1 melted matter is thrown up through the shafts or tubes1 which thus communicate with the mineral regions1 veins of whinstone and basaltes are formed in the interior of the earth4 ,when the melted matter reaches to the surface1 it is thrown out in the form of lava1 and all the other phenomena of volcanoes are produced4 ,lastly1 where melted matter of this kind1 or vapours without being condensed1 have their progress obstructed1 those dreadful concussions are produced1 which seem to threaten the existence even of the earth itself4 ,though terrible1 therefore1 to the present inhabitants of the globe1 the earthquake has its place in the great system of geological operations1 and is part of a series of events1 essential1 as will more clearly appear hereafter1 to the general order1 and to the preservation of the whole4 ,such1 according to this theory1 are the changes which have befallen mineral substances in the bowels of the earth2 and though different for the stratified and unstratified parts of those substances1 they are connected together by the same principle1 or explained by the same cause4 ,it remains to consider that part of the history of both which describes their changes after their elevation to the surface2 and here we shall find new causes introduced1 which are more directly the subjects of observation1 than those hitherto treated of2 causes1 also1 which act on all fossils alike1 and alike prepare them for their ultimate destination4 ,,section ,,iii4 ,,of ,,the ,,phenomena ,,common ,,to ,,stratified ,,and ,,unstratified ,,bodies4 #ib4 ,,the series of changes which fossil bodies are destined to undergo1 does not cease with their elevation above the level of the sea2 it assumes1 however1 a new direction1 and from the moment that they are raised up to the surface1 is constantly exerted in reducing them again under the dominion of the ocean4 ,the solidity is now destroyed which was acquired in the bowels of the earth2 and as the bottom of the sea is the great laboratory1 where loose materials are mineralized and formed into stone1 the atmosphere is the region where stones are decomposed1 and again resolved into earth4 ,this decomposition of all mineral substances1 exposed to the air1 is continual1 and is brought about by a multitude of agents1 both chemical and mechanical1 of which some are known to us1 and many1 no doubt1 remain to be discovered4 ,among the various ariform fluids which compose our atmosphere1 one is already distinguished as the grand principle of mineral decomposition2 the others are not inactive1 and to them we must add moisture1 heat1 and perhaps light2 substances which1 from their affinities to the elements of mineral bodies1 have a power of entering into combination with them1 and of thus diminishing the forces by which they are united to one another4 ,by the action of air and moisture1 the metallic particles1 particularly the iron1 which enters in great abundance into the composition of almost all fossils1 becomes oxydated in such a degree as to lose its tenacity2 so that the texture of the surface is destroyed1 and a part of the body resolved into earth4 #ic4 ,some earths1 again1 such as the calcareous1 are immediately dissolved by water2 and though the quantity so dissolved be extremely small1 the operation1 by being continually renewed1 produces a slow but perpetual corrosion1 by which the greatest rocks must in time be subdued4 ,the action of water in destroying hard bodies into which it has obtained entrance1 is much assisted by the vicissitudes of heat and cold1 especially when the latter extends as far as the point of congelation2 for the water1 when frozen1 occupies a greater space than before1 and if the body is compact enough to refuse room for this expansion1 its parts are torn asunder by a repulsive force acting in every direction4 #id4 ,besides these causes of mineral decomposition1 the action of which we can in some measure trace1 there are others known to us only by their effects4 ,we see1 for instance1 the purest rock crystal affected by exposure to the weather1 its lustre tarnished1 and the polish of its surface impaired1 but we know nothing of the power by which these operations are performed4 ,thus also1 in the precautions which the mineralogist takes to preserve the fresh fracture of his specimens1 we have a proof how indiscriminately all the productions of the fossil kingdom are exposed to the attacks of their unknown enemies1 and we perceive how difficult it is to delay the beginnings of a process which no power whatever can finally counteract4 #ie4 ,the mechanical forces employed in the disintegration of mineral substances1 are more easily marked than the chemical4 ,here again water appears as the most active enemy of hard and solid bodies2 and1 in every state1 from transparent vapour to solid ice1 from the smallest rill to the greatest river1 it attacks whatever has emerged above the level of the sea1 and labours incessantly to restore it to the deep4 ,the parts loosened and disengaged by the chemical agents1 are carried down by the rains1 and1 in their descent1 rub and grind the superficies of other bodies4 ,thus water1 though incapable of acting on hard substances by direct attrition1 is the cause of their being so acted on2 and1 when it descends in torrents1 carrying with it sand1 gravel1 and fragments of rock1 it may be truly said to turn the forces of the mineral kingdom against itself4 ,every separation which it makes is necessarily permanent1 and the parts once detached can never be united1 save at the bottom of the ocean4 #if4 ,but it would far exceed the limits of this sketch1 to pursue the causes of mineral decomposition through all their forms4 ,it is sufficient to remark1 that the consequence of so many minute1 but indefatigable agents1 all working together1 and having gravity in their favour1 is a system of universal decay and degradation1 which may be traced over the whole surface of the land1 from the mountain top to the sea shore4 ,that we may perceive the full evidence of this truth1 one of the most important in the natural history of the globe1 we will begin our survey from the latter of these stations1 and retire gradually toward the former4 #ig4 ,if the coast is bold and rocky1 it speaks a language easy to be interpreted4 ,its broken and abrupt contour1 the deep gulfs and salient promontories by which it is indented1 and the proportion which these irregularities bear to the force of the waves1 combined with the inequality of hardness in the rocks1 prove1 that the present line of the shore has been determined by the action of the sea4 ,the naked and precipitous cliffs which overhang the deep1 the rocks hollowed1 perforated1 as they are farther advanced in the sea1 and at last insulated1 lead to the same conclusion1 and mark very clearly so many different stages of decay4 ,it is true1 we do not see the successive steps of this progress exemplified in the states of the same individual rock1 but we see them clearly in different individuals2 and the conviction thus produced1 when the phenomena are sufficiently multiplied and varied1 is as irresistible1 as if we saw the changes actually effected in the moment of observation4 ,on such shores1 the fragments of rock once detached1 become instruments of further destruction1 and make a part of the powerful artillery with which the ocean assails the bulwarks of the land3 they are impelled against the rocks1 from which they break off other fragments1 and the whole are thus ground against one another2 whatever be their hardness1 they are reduced to gravel1 the smooth surface and round figure of which1 are the most certain proofs of a detritus which nothing can resist4 #ih4 ,again1 where the sea coast is flat1 we have abundant evidence of the degradation of the land in the beaches of sand and small gravel2 the sand banks and shoals that are continually changing2 the alluvial land at the mouths of the rivers2 the bars that seem to oppose their discharge into the sea1 and the shallowness of the sea itself4 ,on such coasts1 the land usually seems to gain upon the sea1 whereas1 on shores of a bolder aspect1 it is the sea that generally appears to gain upon the land4 ,what the land acquires in extent1 however1 it loses in elevation2 and1 whether its surface increase or diminish1 the depredations made on it are in both cases evinced with equal certainty4 #ii4 ,if we proceed in our survey from the shores1 inland1 we meet at every step with the fullest evidence of the same truths1 and particularly in the nature and economy of rivers4 ,every river appears to consist of a main trunk1 fed from a variety of branches1 each running in a valley proportioned to its size1 and all of them together forming a system of vallies1 communicating with one another1 and having such a nice adjustment of their declivities1 that none of them join the principal valley1 either on too high or too low a level2 a circumstance which would be infinitely improbable1 if each of these vallies were not the work of the stream that flows in it4 ,if indeed a river consisted of a single stream1 without branches1 running in a straight valley1 it might be supposed that some great concussion1 or some powerful torrent1 had opened at once the channel by which its waters are conducted to the ocean2 but1 when the usual form of a river is considered1 the trunk divided into many branches1 which rise at a great distance from one another1 and these again subdivided into an infinity of smaller ramifications1 it becomes strongly impressed upon the mind1 that all these channels have been cut by the waters themselves2 that they have been slowly dug out by the washing and erosion of the land2 and that it is by the repeated touches of the same instrument1 that this curious assemblage of lines has been engraved so deeply on the surface of the globe4 #ajj4 ,the changes which have taken place in the courses of rivers1 are also to be traced1 in many instances1 by successive platforms1 of flat alluvial land1 rising one above another1 and marking the different levels on which the river has run at different periods of time4 ,of these1 the number to be distinguished1 in some instances1 is not less than four1 or even five2 and this necessarily carries us back1 like all the operations we are now treating of1 to an antiquity extremely remote3 for1 if it be considered1 that each change which the river makes in its bed1 obliterates at least a part of the monuments of former changes1 we shall be convinced1 that only a small part of the progression can leave any distinct memorial behind it1 and that there is no reason to think1 that1 in the part which we see1 the beginning is included4#bi ,footnote #bi3 ,,note ,,xvi4 #aja4 ,in the same manner1 when a river undermines its banks1 it often discovers deposits of sand and gravel1 that have been made when it ran on a higher level than it does at present4 ,in other instances1 the same strata are seen on both the banks1 though the bed of the river is now sunk deep between them1 and perhaps holds as winding a course through the solid rock1 as if it flowed along the surface2 a proof that it must have begun to sink its bed1 when it ran through such loose materials as opposed but a very inconsiderable resistance to its stream4 ,a river1 of which the course is both serpentine and deeply excavated in the rock1 is among the phenomena1 by which the slow waste of the land1 and also the cause of that waste1 are most directly pointed out4 #ajb4 ,it is1 however1 where rivers issue through narrow defiles among mountains1 that the identity of the strata on both sides is most easily recognised1 and remarked at the same time with the greatest wonder4 ,on observing the ,potowmack1 where it penetrates the ridge of the ,allegany mountains1 or the ,irtish1 as it issues from the defiles of ,altai1 there is no man1 however little addicted to geological speculations1 who does not immediately acknowledge1 that the mountain was once continued quite across the space in which the river now flows2 and1 if he ventures to reason concerning the cause of so wonderful a change1 he ascribes it to some great convulsion of nature1 which has torn the mountain asunder1 and opened a passage for the waters4 ,it is only the philosopher1 who has deeply meditated on the effects which action long continued is able to produce1 and on the simplicity of the means which nature employs in all her operations1 who sees in this nothing but the gradual working of a stream1 that once flowed over the top of the ridge which it now so deeply intersects1 and has cut its course through the rock1 in the same way1 and almost with the same instrument1 by which the lapidary divides a block of marble or granite4 #ajc4 ,it is highly interesting to trace up1 in this manner1 the action of causes with which we are familiar1 to the production of effects1 which at first seem to require the introduction of unknown and extraordinary powers2 and it is no less interesting to observe1 how skilfully nature has balanced the action of all the minute causes of waste1 and rendered them conducive to the general good4 ,of this we have a most remarkable instance1 in the provision made for preserving the soil1 or the coat of vegetable mould1 spread out over the surface of the earth4 ,this coat1 as it consists of loose materials1 is easily washed away by the rains1 and is continually carried down by the rivers into the sea4 ,this effect is visible to every one2 the earth is removed not only in the form of sand and gravel1 but its finer particles suspended in the waters1 tinge those of some rivers continually1 and those of all occasionally1 that is1 when they are flooded or swollen with rains4 ,the quantity of earth thus carried down1 varies according to circumstances2 it has been computed1 in some instances1 that the water of a river in a flood1 contains earthy matter suspended in it1 amounting to more than the two hundred and fiftieth part of its own bulk4#cj ,the soil1 therefore1 is continually diminished1 its parts being transported from higher to lower levels1 and finally delivered into the sea4 ,but it is a fact1 that the soil1 notwithstanding1 remains the same in quantity1 or at least nearly the same1 and must have done so1 ever since the earth was the receptacle of animal or vegetable life4 ,the soil1 therefore1 is augmented from other causes1 just as much1 at an average1 as it is diminished by that now mentioned2 and this augmentation evidently can proceed from nothing but the constant and slow disintegration of the rocks4 ,in the permanence1 therefore1 of a coat of vegetable mould on the surface of the earth1 we have a demonstrative proof of the continual destruction of the rocks2 and cannot but admire the skill1 with which the powers of the many chemical and mechanical agents employed in this complicated work1 are so adjusted1 as to make the supply and the waste of the soil exactly equal to one another4 ,footnote #cj3 ,see ,lehman1 ,traits de ,phys4 c4 tom4 iii4 p4 #cei4 ,note4 #ajd4 ,before we take leave of the rivers and the plains1 we must remark another fact1 often observed in the natural history of the latter1 and clearly evincing the former existence of immense bodies of strata1 in situations from which they have now entirely disappeared4 ,the fact here alluded to is1 the great quantity of round and hard gravel1 often to be met with in the soil1 under such circumstances1 as prove1 that it can only have come from the decomposition of rocks1 that once occupied the very ground over which this gravel is now spread4 ,in the chalk country1 for instance1 about ,london1 the quantity of flints in the soil is every where great2 and1 in particular situations1 nothing but flinty gravel is found to a considerable depth4 ,now1 the source from which these flints are derived is quite evident1 for they are precisely the same with those contained in the chalk beds1 wherever these last are found undisturbed1 and from the destruction of such beds they have no doubt originated4 ,hence a great thickness of chalk must have been decomposed1 to yield the quantity of flints now in the soil of these countries2 for the flints are but thinly scattered through the native chalk1 compared with their abundance in the loose earth4 ,to afford1 for example1 such a body of flinty gravel as is found about ,kensington1 what an enormous quantity of chalk rock must have been destroyed8 #aje4 ,this argument1 which ,dr ,hutton has applied particularly to the chalk countries1 may be extended to many others4 ,the great plain of ,crau1 near the mouth of the ,rhone1 is well known1 and was regarded with wonder1 even in ages when the natural history of the globe was not an object of much attention4 ,the immense quantity of large round gravel-stones1 with which this extensive plain is entirely covered1 has been supposed1 by some mineralogists1 to have been brought down by the ,durance1 and other torrents1 from the ,alps2 but1 on further examination1 has been found to be of the same kind that is contained in certain horizontal layers of pudding-stone1 which are the basis of the whole plain4 ,it cannot be doubted1 therefore1 that the vast body of gravel spread over it1 has originated from the destruction of layers of the same rock1 which may perhaps have risen to a great height above what is now the surface4 ,indeed1 from knowing the depth of the gravel that covers the plain1 and the average quantity of the like gravel contained in a given thickness of rock1 one might estimate how much of the latter has been actually worn away4 ,whether data precise enough could be found1 to give any weight to such a computation1 must be left fer future inquiry to determine4#ca ,footnote #ca3 ,,note ,,xvii4 #ajf4 ,in these instances1 chalk and pudding-stone1 by containing in them parts infinitely less destructible than their general mass1 have1 after they are worn away1 left behind them very unequivocal marks of their existence4 ,the same has happened in the case of mineral veins1 where the substances least subject to dissolution have remained1 and are scattered at a great distance from their native place4 ,thus gold1 the least liable to decomposition of all the metals1 is very generally diffused through the earth1 and is found1 in a greater or less abundance1 in the sand of almost all rivers4 ,but the native place of this mineral is the solid rock1 or the veins and cavities contained in the rock1 and from thence it must have made its way into the soil4 ,this1 therefore1 is another proof of the vast extent to which the degradation of the land1 and of the rock1 which is the basis of it1 has been earned2 and consequently1 of the great difference between the elevation and shape of the earth's surface in the present1 and in former ages4 #ajg4 ,the veins of tin furnish an argument of the same kind4 ,the ores of this metal are very indestructible1 and little subject to decomposition1 so that they remain very long in the ground without change4 ,where there are tin veins1 as in ,cornwall1 the tin-stone or tin ore is found in great abundance in such vallies and streams as have the same direction with the veins2 and hence the streaming1 as it is called1 or washing of the earth1 to obtain the tin-stone from it4 ,now1 if it be considered1 that none of this ore can have come into the soil but from parts of a vein actually destroyed1 it must appear evident that a great waste of these veins has taken place1 and consequently of the schistus or granite in which they are contained4 #ajh4 ,these lessons1 which the geologist is taught in flat and open countries1 become more striking1 by the study of those ,alpine tracts1 where the surface of the earth attains its greatest elevation4 ,if we suppose him placed for the first time in the midst of such a scene1 as soon as he has recovered from the impression made by the novelty and magnificence of the spectacle before him1 he begins to discover the footsteps of time1 and to perceive1 that the works of nature1 usually deemed the most permanent1 are those on which the characters of vicissitude are most deeply imprinted4 ,he sees himself in the midst of a vast ruin1 where the precipices which rise on all sides with such boldness and asperity1 the sharp peaks of the granite mountains1 and the huge fragments that surround their bases1 do but mark so many epochs in the progress of decay1 and point out the energy of those destructive causes1 which even the magnitude and solidity of such great bodies have been unable to resist4 #aji4 ,the result of a more minute investigation1 is in perfect unison with this general impression4 ,whence is it1 that the elevation of mountains is so obviously connected with the hardness and indestructibility of the rocks which compose them8 ,why is it1 that a lofty mountain of soft and secondary rock is no where to be found2 and that such chains1 as the ,pyrenees or the ,alps1 never consist of any but the hardest stone1 of granite for instance1 or of those primary strata1 which1 if we are to credit the preceding theory1 have been twice heated in the fires1 and twice tempered in the waters1 of the mineral regions8 ,is it not plain that this arises1 not from any direct connection between the hardness of stones1 and their height in the atmosphere1 but from this1 that the waste and detritus to which all things are subject1 will not allow soft and weak substances to remain long in an exposed and elevated situation8 ,were it not for this1 the secondary rocks1 being in position superincumbent on the primary1 ought to be the highest of the two1 and should cover the primary1 7as they no doubt have at one time done17 in the highest as well as the lowest situations1 or among the mountains as well as in the plains4 #aaj4 ,again1 wherefore is it1 that among all mountains1 remarkable for their ruggedness and asperity1 the rock1 on examination1 is always found of very unequal destructibility1 some parts yielding to the weather1 and to the other causes of disintegration1 much more slowly than the rest1 and having strength sufficient to support themselves1 when left alone1 in slender pyramids1 bold projections1 and overhanging cliffs8 ,where1 on the other hand1 the rock wastes uniformly1 the mountains are similar to one another2 their swells and slopes are gentle1 and they are bounded by a waving and continuous surface4 ,the intermediate degrees of resistance which the rocks oppose to the causes of destruction1 produce intermediate forms4 ,it is this which gives to the mountains1 of every different species of rock1 a different habit and expression1 and which1 in particular1 has imparted to those of granite that venerable and majestic character1 by which they rarely fail to be distinguished4 #aaa4 ,the structure of the vallies among mountains1 shows clearly to what cause their existence is to be ascribed4 ,here we have first a large valley1 communicating directly with the plain1 and winding between high ridges of mountains1 while the river in the bottom of it descends over a surface1 remarkable1 in such a scene1 for its uniform declivity4 ,into this1 open a multitude of transverse or secondary vallies1 intersecting the ridges on either side of the former1 each bringing a contribution to the main stream1 proportioned to its magnitude2 and1 except where a cataract now and then intervenes1 all having that nice adjustment in their levels1 7#ii47 which is the more wonderful1 the greater the irregularity of the surface4 ,these secondary vallies have others of a smaller size opening into them2 and1 among mountains of the first order1 where all is laid out on the greatest scale1 these ramifications are continued to a fourth1 and even a fifth1 each diminishing in size as it increases in elevation1 and as its supply of water is less4 ,through them all1 this law is in general observed1 that where a higher valley joins a lower one1 of the two angles which it makes with the latter1 that which is obtuse is always on the descending side2 a law that is the same with that which regulates the confluence of streams running on a surface nearly of uniform inclination4 ,this alone is a proof that the vallies are the work of the streams2 and indeed what else but the water itself1 working its way through obstacles of unequal resistance1 could have opened or kept up a communication between the inequalities of an irregular and alpine surface8 #aab4 ,many more arguments1 all leading to the same conclusion1 may be deduced from the general facts1 known in the natural history of mountains2 and1 if the ,oreologist would trace back the progress of waste1 till he come in sight of that original structure1 of which the remains are still so vast1 he perceives an immense mass of solid rock1 naked and unshapely1 as it first emerged from the deep1 and incomparably greater than all that is now before him4 ,the operation of rains and torrents1 modified by the hardness and tenacity of the rock1 has worked the whole into its present form2 has hollowed out the vallies1 and gradually detached the mountains from the general mass1 cutting down their sides into steep precipices at one place1 and smoothing them into gentle declivities at another4 ,from this has resulted a transportation of materials1 which1 both for the quantity of the whole1 and the magnitude of the individual fragments1 must seem incredible to every one1 who has not learned to calculate the effects of continued action1 and to reflect1 that length of time can convert accidental into steady causes4 ,hence fragments of rock1 from the central chain1 are found to have travelled into distant vallies1 even where many inferior ridges intervene3 hence the granite of ,mont ,blanc is seen in the plains of ,lombardy1 or on the sides of ,jura2 and the ruins of the ,carpathian mountains lie scattered over the shores of the ,baltic4#cb ,footnote #cb3 ,,note ,,xviii4 #aac4 ,thus1 with ,dr ,hutton1 we shall be disposed to consider those great chains of mountains1 which traverse the surface of the globe1 as cut out of masses vastly greater1 and more lofty than any thing that now remains4 ,the present appearances afford no data for calculating the original magnitude of these masses1 or the height to which they may have been elevated4 ,the nearest estimate we can form is1 where a chain or group of mountains1 like those of ,rosa in the ,alps1 is horizontally stratified1 and where1 of consequence1 the undisturbed position of the mineral beds enables us to refer the whole of the present inequalities of the surface to the operation of waste or decay4 ,these mountains1 as they now stand1 may not inaptly be compared to the pillars of earth which workmen leave behind them1 to afford a measure of the whole quantity of earth which they have removed4 ,as the pillars1 7considering the mountains as such17 are in this case of less height than they originally were1 so the measure furnished by them is but a limit1 which the quantity sought must necessarily exceed4 #aad4 ,such1 according to ,dr ,hutton's theory1 are the changes which the daily operations of waste have produced on the surface of the globe4 ,these operations1 inconsiderable if taken separately1 become great1 by conspiring all to the same end1 never counteracting one another1 but proceeding1 through a period of indefinite extent1 continually in the same direction4 ,thus every thing descends1 nothing returns upward2 the hard and solid bodies every where dissolve1 and the loose and soft no where consolidate4 ,the powers which tend to preserve1 and those which tend to change the condition of the earth's surface1 are never in equilibrio2 the latter are1 in all cases1 the most powerful1 and1 in respect of the former1 are like living in comparison of dead forces4 ,hence the law of decay is one which suffers no exception3 ,the elements of all bodies were once loose and unconnected1 and to the same state nature has appointed that they should all return4 #aae4 ,it affords no presumption against the reality of this progress1 that1 in respect of man1 it is too slow to be immediately perceived3 ,the utmost portion of it to which our experience can extend1 is evanescent1 in comparison with the whole1 and must be regarded as the momentary increment of a vast progression1 circumscribed by no other limits than the duration of the world4 ,,time performs the office of integrating the infinitesimal parts of which this progression is made up2 it collects them into one sum1 and produces from them an amount greater than any that can be assigned4 #aaf4 ,while on the surface of the earth so much is every where going to decay1 no new production of mineral substances is found in any region accessible to man4 ,the instances of what are called petrifactions1 or the formation of stony substances by means of water1 which we sometimes observe1 whether they be ferruginous concretions1 or calcareous1 or1 as happens in some rare cases1 siliceous stalactites1 are too few in number1 and too inconsiderable in extent1 to be deemed material exceptions to this general rule4 ,the bodies thus generated1 also1 are no sooner formed1 than they become subject to waste and dissolution1 like all the other hard substances in nature2 so that they but retard for a while the progress by which they are all resolved into dust1 and sooner or later committed to the bosom of the deep4 #aag4 ,we are not1 however1 to imagine1 that there is no where any means of repairing this waste2 for1 on comparing the conclusion at which we are now arrived1 viz4 that the present continents are all going to decay1 and their materials descending into the ocean1 with the proposition first laid down1 that these same continents are composed of materials which must have been collected from the decay of former rocks1 it is impossible not to recognise two corresponding steps of the same progress2 of a progress1 by which mineral substances are subjected to the same series of changes1 and alternately wasted away and renovated4 ,in the same manner1 as the present mineral substances derive their origin from substances similar to themselves2 so1 from the land now going to decay1 the sand and gravel forming on the sea shore1 or in the beds of rivers2 from the shells and corals1 which in such enormous quantities are every day accumulated in the bosom of the sea2 from the drift wood1 and the multitude of vegetable and animal remains continually deposited in the ocean3 from all these we cannot doubt1 that strata are now forming in those regions1 to which nature seems to have confined the powers of mineral reproduction2 from which1 after being consolidated1 they are again destined to emerge1 and to exhibit a series of changes similar to the past4#cc ,footnote #cc3 ,,note ,,xix4 #aah4 ,how often these vicissitudes of decay and renovation have been repeated1 is not for us to determine3 they constitute a series1 of which1 as the author of this theory has remarked1 we neither see the beginning nor the end2 a circumstance that accords well with what is known concerning other parts of the economy of the world4 ,in the continuation of the different species of animals and vegetables that inhabit the earth1 we discern neither a beginning nor an end2 and1 in the planetary motions1 where geometry has carried the eye so far both into the future and the past1 we discover no mark1 either of the commencement or the termination of the present order4#cd ,it is unreasonable1 indeed1 to suppose1 that such marks should any where exist4 ,the ,author of nature has not given laws to the universe1 which1 like the institutions of men1 carry in themselves the elements of their own destruction4 ,he has not permitted1 in his works1 any symptom of infancy or of old age1 or any sign by which we may estimate either their fixture or their past duration4 ,he may put an end1 as be no doubt gave a beginning1 to the present system1 at some determinate period2 but we may safely conclude1 that this great catastrophe will not be brought about by any of the laws now existing1 and that it is not indicated by any thing which we perceive4 ,footnote #cd3 ,,note ,,xx4 #aai4 ,to assert1 therefore1 that1 in the economy of the world1 we see no mark1 either of a beginning or an end1 is very different from affirming1 that the world had no beginning1 and will have no end4 ,the first is a conclusion justified by common sense1 as well as sound philosophy2 while the second is a presumptuous and unwarrantable assertion1 for which no reason from experience or analogy can ever be assigned4 ,dr ,hutton might1 therefore1 justly complain of the uncandid criticism1 which1 by substituting the one of these assertions for the other1 endeavoured to load his theory with the reproach of atheism and impiety4 ,mr ,,kirwan1 in bringing forward this harsh and ill-founded censure1 was neither animated by the spirit1 nor guided by the maxims of true philosophy4 ,by the spirit of philosophy1 he must have been induced to reflect1 that such poisoned weapons as he was preparing to use1 are hardly ever allowable in scientific contest1 as having a less direct tendency to overthrow the system1 than to hurt the person of an adversary1 and to wound1 perhaps incurably1 his mind1 his reputation1 or his peace4 ,by the maxims of philosophy1 he must have been reminded1 that1 in no part of the history of nature1 has any mark been discovered1 either of the beginning or the end of the present order2 and that the geologist sadly mistakes1 both the object of his science and the limits of his understanding1 who thinks it his business to explain the means employed by ,,infinite ,,wisdom for establishing the laws which now govern the world4 ,by attending to these obvious considerations1 ,mr ,kirwan would have avoided a very illiberal and ungenerous proceeding2 and1 however he might have differed from ,dr ,hutton as to the truth of his opinions1 he would not have censured their tendency with such rash and unjustifiable severity4 ,but1 if this author may be blamed for wanting the temper1 or neglecting the rules1 of philosophic investigation1 he is hardly less culpable1 for having so slightly considered the scope and spirit of a work which he condemned so freely4 ,in that work1 instead of finding the world represented as the result of necessity or chance1 which might be looked for1 if the accusations of atheism or impiety were well founded1 we see every where the utmost attention to discover1 and the utmost disposition to admire1 the instances of wise and beneficent design manifested in the structure1 or economy of the world4 ,the enlarged views of these1 which his geological system afforded1 appeared to ,dr ,hutton himself as its most valuable result4 ,they were the parts of it which he contemplated with greatest delight2 and he would have been less flattered1 by being told of the ingenuity and originality of his theory1 than of the addition which it had made to our knowledge of final causes4 ,it was natural1 therefore1 that he should be hurt by an attempt to accuse him of opinions1 so different from those which he had always taught2 and if he answered ,mr ,kirwan's attack with warmth or asperity1 we must ascribe it to the indignation excited by unmerited reproach4 #abj4 ,but to return to the natural history of the earth3 ,though there be in it no data1 from which the commencement of the present order can be ascertained1 there are many by which the existence of that order may be traced back to an antiquity extremely remote4 ,the beds of primitive schistus1 for instance1 contain sand1 gravel1 and other materials1 collected1 as already shown1 from the dissolution of mineral bodies2 which bodies1 therefore1 must have existed long before the oldest part of the present land was formed4 ,again1 in this gravel we sometimes find pieces of sandstone1 and of other compound rocks1 by which we are of course carried back a step farther1 so as to reach a system of things1 from which the present is the third in succession2 and this may be considered as the most ancient epocha1 of which any memorial exists in the records of the fossil kingdom4 #aba4 ,next in the order of time to the consolidation of the primary strata1 we must place their elevation1 when1 from being horizontal1 and at the bottom of the sea1 they were broken1 set on edge1 and raised to the surface4 ,it is even probable1 as formerly observed1 that to this succeeded a depression of the same strata1 and a second elevation1 so that they have twice visited the superior1 and twice the inferior regions4 ,during the second immersion1 were formed1 first1 the great bodies of pudding-stone1 that in so many instances lie immediately above them2 and next were deposited the strata that are strictly denominated secondary4 #abb4 ,the third great event1 was the raising up of this compound body of old and new strata from the bottom of the sea1 and forming it into the dry land1 or the continents1 as they now exist4#ce ,contemporary with this1 we must suppose the injection of melted matter among the strata1 and the consequent formation of the crystallized and unstratified rocks1 namely1 the granite1 metallic veins1 and veins of porphyry and whinstone4 ,this1 however1 is to be considered as embracing a period of great duration2 and it must always be recollected1 that veins are found of very different formation2 so that when we speak generally1 it is perhaps impossible to state any thing more precise concerning their antiquity1 than that they are posterior to the strata1 and that the veins of whinstone seem to be the most recent of all1 as they traverse every other4 ,footnote #ce3 ,,note ,,xxi4 #abc4 ,in the fourth place1 with respect to time1 we must class the facts that regard the detritus and waste of the land1 and must carefully distinguish them from the more ancient phenomena of the mineral kingdom4 ,here we are to reckon the shaping of all the present inequalities of the surface2 the formation of hills of gravel1 and of what have been called tertiary strata1 consisting of loose and unconsolidated materials2 also collections of shells not mineralised1 like those in ,turaine2 such petrifactions as those contained in the rock of ,gibraltar1 on the coast of ,dalmatia1 and in the caves of ,bayreuth4 ,the bones of land animals found in the soil1 such as those of ,siberia1 or ,north ,america1 are probably more recent than any of the former4#cf ,footnote #cf3 ,,note ,,xxii4 #abd4 ,these phenomena1 then1 are all so many marks of the lapse of time1 among which the principles of geology enable us to distinguish a certain order1 so that we know some of them to be more1 and others to be less distant1 but without being able to ascertain1 with any exactness1 the proportion of the immense intervals which separate them4 ,these intervals admit of no comparison with the astronomical measures of time2 they cannot be expressed by the revolutions of the sun or of the moon2 nor is there any synchronism between the most recent epoch as of the mineral kingdom1 and the most ancient of our ordinary chronology4 #abe4 ,on what is now said is grounded another objection to ,dr ,hutton's theory1 namely1 that the high antiquity ascribed by it to the earth1 is inconsistent with that system of chronology which rests on the authority of the ,sacred ,writings4 ,this objection would no doubt be of weight1 if the high antiquity in question were not restricted merely to the globe of the earth1 but were also extended to the human race4 ,that the origin of mankind does not go back beyond six or seven thousand years1 is a position so involved in the narrative of the ,mosaic books1 that any thing inconsistent with it1 would no doubt stand in opposition to the testimony of those ancient records4 ,on this subject1 however1 geology is silent2 and the history of arts and sciences1 when traced as high as any authentic monuments extend1 refers the beginnings of civilization to a date not very different from that which has just been mentioned1 and infinitely within the limits of the most recent of the epoch as1 marked by the physical revolutions of the globe4 ,on the other hand1 the authority of the ,sacred ,books seems to be but little interested in what regards the mere antiquity of the earth itself2 nor does it appear that their language is to be understood literally concerning the age of that body1 any more than concerning its figure or its motion4 ,the theory of ,dr ,hutton stands here precisely on the same footing with the system of ,,copernicus2 for there is no reason to suppose1 that it was the purpose of revelation to furnish a standard of geological1 any more than of astronomical science4 ,it is admitted1 on all hands1 that the ,scriptures are not intended to resolve physical questions1 or to explain matters in no way related to the morality of human actions2 and if1 in consequence of this principle1 a considerable latitude of interpretation were not allowed1 we should continue at this moment to believe1 that the earth is flat2 that the sun moves round the earth2 and that the circumference of a circle is no more than three times its diameter4 ,it is but reasonable1 therefore1 that we should extend to the geologist the same liberty of speculation1 which the astronomer and mathematician are already in possession of2 and this may be done1 by supposing that the chronology of ,,moses relates only to the human race4 ,this liberty is not more necessary to ,dr ,hutton than to other theorists4 ,no ingenuity has been able to reconcile the natural history of the globe with the opinion of its recent origin2 and accordingly the cosmologies of ,kirwan and ,de ,luc1 though contrived with more mineralogical skill1 are not less forced and unsatisfactory than those of ,burnet and ,whiston4 #abf4 ,it is impossible to look back on the system which we have thus endeavoured to illustrate1 without being struck with the novelty and beauty of the views which it sets before us4 ,the very plan and scope of it distinguish it from all other theories of the earth1 and point it out as a work of great and original invention4 ,the sole object of such theories has hitherto been1 to explain the manner in which the present laws of the mineral kingdom were first established1 or began to exist1 without treating of the manner in which they now proceed1 and by which their continuance is provided for4 ,the authors of these theories have accordingly gone back to a state of things altogether unlike the present1 and have confined their reasonings1 or their fictions1 to a crisis which never has existed but once1 and which never can return4 ,dr ,hutton1 on the other hand1 has guided his investigation by the philosophical maxim1 ,causam naturalem et assiduam qurimus1 non raram et fortuitam4 ,his theory1 accordingly1 presents us with a system of wise and provident economy1 where the same instruments are continually employed1 and where the decay and renovation of fossils being carried on at the same time in the different regions allotted to them1 preserve in the earth the conditions essential for the support of animal and vegetable life4 ,we have been long accustomed to admire that beautiful contrivance in nature1 by which the water of the ocean1 drawn up in vapour by the atmosphere1 imparts1 in its descent1 fertility to the earth1 and becomes the great cause of vegetation and of life2 but now we find1 that this vapour not only fertilizes1 but creates the soil2 prepares it from the solid rock1 and1 after employing it in the great operations of the surface1 carries it back into the regions where all its mineral characters are renewed4 ,thus1 the circulation of moisture through the air1 is a prime mover1 not only in the annual succession of the seasons1 but in the great geological cycle1 by which the waste and reproduction of entire continents is circumscribed4 ,perhaps a more striking view than this1 of the wisdom that presides over nature1 was never presented by any philosophical system1 nor a greater addition ever made to our knowledge of final causes4 ,it is an addition which gives consistency to the rest1 by proving1 that equal foresight is exerted in providing for the whole and for the parts1 and that no less a care is taken to maintain the constitution of the earth1 than to preserve the tribes of animals and vegetables which dwell on its surface4 ,in a word1 it is the peculiar excellence of this theory1 that it ascribes to the phenomena of geology an order similar to that which exists in the provinces of nature with which we are best acquainted2 that it produces seas and continents1 not by accident1 but by the operation of regular and uniform causes2 that it makes the decay of one part subservient to the restoration of another1 and gives stability to the whole1 not by perpetuating individuals1 but by reproducing them in succession4 #abg4 ,again1 in the detail of this theory1 and the ample induction on which it is founded1 we meet with many facts and observations1 either entirely new1 or hitherto very imperfectly understood4 ,thus1 the veins which proceed from masses of granite1 and penetrate the incumbent schistus1 had either escaped the observation of former mineralogists1 or the importance of the phenomenon had been entirely overlooked4 ,dr ,hutton has described the appearances with great accuracy1 and drawn from them the most interesting conclusions4 ,at the junction of the primary and secondary strata1 the facts which he has noted had been observed by others2 but no one ,i think had so fully understood the language which they speak1 or had so clearly perceived the consequences that necessarily follow from them4 ,he is the first who distinctly pointed out the characters which distinguish whinstone from lava1 and who explained the true relation that subsists between these substances4 ,he also discovered the induration of the strata1 in contact with veins of whin1 and the charring of the coal in their vicinity4 ,his theory also enabled him to determine the affinity of whinstone and granite to one another1 and their relation to the other great bodies of the mineral kingdom4 ,to the observations of the same excellent geologist1 we are indebted for the knowledge of the general and important fact1 that all the hard substances of the mineral kingdom1 when elevated into the atmosphere1 have a tendency to decay1 and are subject to a disintegration and waste1 to which no limit can be set but that of their entire destruction2 that no provision is made on the surface for repairing this waste1 and that there1 no new fossil is produced2 that the formation of all the varied scenery which the surface of the earth exhibits1 depends on the operation of causes1 the momentary exertions of which are familiar to us1 though we knew not before the effects which their accumulated action was able to produce4 ,these are facts in the natural history of the earth1 the discovery of which is due to ,dr ,hutton2 and1 should we lay all further speculation aside1 and consider the theory of the earth as a work too great to be attempted by man1 we must still regard the phenomena and laws just mentioned1 as forming a solid and valuable addition to our knowledge4 #abh4 ,if we would compare this theory with others1 as to the invisible agents which it employs1 we must consider1 that fire and water are the two powers which all of them must make use of1 so that they can differ from one another only by the way in which they combine these powers4 ,in ,dr ,hutton's system1 water is first employed to deposit and arrange1 and then fire to consolidate1 mineralize1 and lastly1 to elevate the strata2 but with respect to the unstratified or crystallized substances1 the action of fire only is recognised4 ,the system having least affinity to this is the ,neptunian1 which ascribes the formation of all minerals to the action of water alone1 and extends this hypothesis even to the unstratified rocks4 ,here1 therefore1 the action of fire is entirely excluded2 and the ,neptunists have certainly made a great sacrifice to the love of truth1 or of paradox1 in rejecting the assistance of so powerful an auxiliary4#cg ,footnote #cg3 ,,note ,,xxiii4 #abi4 ,in the systems which employ the agency of the latter element1 we are to look for a greater resemblance to that of ,dr ,hutton1 though many and great marks of distinction are easily perceived4 ,in the cosmologies1 for example1 of ,,leibnitz and ,,buffon1 fire and water are both employed1 as well as in this2 but they are employed in a reverse order4 ,these philosophers introduce the action of fire first1 and then the action of water1 which is to invert the order of nature altogether1 as the consolidation of the rocks must be posterior to their stratification4 ,indeed1 the theory of ,buffon is singularly defective3 besides inverting the order of the two great operations of stratification and consolidation1 and of course giving no real explanation of the latter1 it gives no account of the elevation1 or highly inclined position of the strata2 it makes no distinction between stratified and unstratified bodies1 nor does it offer any but the most unsatisfactory explanation of the inequalities of the earth's surface4 ,this system1 therefore1 has but a very distant resemblance to the ,huttonian theory4#ch ,footnote #ch3 ,,note ,,xxiv4 #acj4 ,the system of ,,lazzaro ,,moro has been remarked as approaching nearer to this theory than any other2 and it is certain1 that one very important principle is common to them both4 ,the theory of the ,italian geologist was chiefly directed to the explanation of the remains of marine animals1 which are found in mountains far from the sea2 and it appears to have been suggested to him by the phenomena of the ,campi ,phlegri1 and by the production of the new island of ,santorini in the ,archipelago4 ,he accordingly supposes1 that the islands and continents have been all raised up1 like the above-mentioned island1 from the bottom of the sea1 by the force of volcanic fire3 that these fires began to burn under the bottom of the ocean1 soon after the creation of the world1 when as yet the ocean covered the whole earth3 that they at first elevated a portion of the land2 and in this primitive land no shells are found1 as the original ocean was destitute of fish4 ,the volcanoes continuing to burn1 under the sea1 after the creation of animated nature1 the strata that were then raised up by their action were full of shells and other marine objects2 and1 from the violence with which they were elevated1 arose the contortions and inclined position which they frequently possess4#ci ,footnote #ci3 ,d ,crostacei1 et degli altri ,marini ,corpi1 che si trovano su' ,monti3 di ,ant4 ,lazzaro ,moro4 ,venezia4 #agdj4 ,this system is imperfect1 as it makes no peculiar provision for the consolidation of the strata1 which1 according to it1 as well as the ,neptunian system1 must be ascribed to the action1 not of fire1 but of water4 ,no account is given of the mineralization of the shells found in the strata1 or of the difference between them and the shells found loose at the bottom of the sea2 and no distinction is made between stratified and unstratified substances4 ,but1 with all this1 ,lazzaro ,moro has certainly the merit of having perceived1 that some other power than that which deposited the strata1 must have been employed for their elevation1 and that they have endured the action of a disturbing force4 #aca4 ,from this comparison it appears1 that ,dr ,hutton's theory is sufficiently distinct1 even from the theories which approach to it most nearly1 to merit1 in the strictest sense1 the appellation of new and original4 ,there are indeed few inventions or discoveries1 recorded in the history of science1 to which nearer approaches were not made before they were fully unfolded4 ,it therefore very well deserves to be distinguished by a particular name2 and1 if it behoves us to follow the analogy observed in the names of the two great systems1 which at present divide the opinions of geologists1 we may join ,mr ,kirwan in calling this the ,,plutonic ,,system4 ,for my own part1 ,i would rather have it characterized by a less splendid1 but juster name1 that of the ,,huttonian ,,theory4 #acb4 ,the circumstance1 however1 which gives to this theory its peculiar character1 and exalts it infinitely above all others1 is the introduction of the principle of pressure1 to modify the effects of heat when applied at the bottom of the sea4 ,this is in fact the key to the grand enigma of the mineral kingdom1 where1 while one set of phenomena indicates the action of fire1 another set1 equally remarkable1 seems to exclude the possibility of that action1 by presenting us with mineral substances1 in such a state as they could never have been brought into by the operation of the fires we see at the surface of the earth4 ,these two classes of phenomena are reconciled together1 by admitting the power of compression to confine the volatile parts of bodies when heat is applied to them1 and to force them1 in many instances1 to undergo fusion1 instead of being calcined or dissipated by burning or inflammation4 ,in this hypothesis1 which some affect to consider as a principle gratuitously assumed1 there appears to me nothing but a very fair and legitimate generalization of the properties of heat4 ,combustion and inflammation are chemical processes1 to which other conditions are required1 besides the presence of a high temperature4 ,the state of the mineral regions makes it reasonable to presume1 that these conditions are wanting in the bowels of the earth1 where1 of consequence1 we have a right to look for nothing but expansion and fusion1 the only operations which seem essential to heat1 and inseparable from the application of it1 in certain degrees1 to certain substances4 ,though this principle1 therefore1 had no countenance from analogy1 the admirable simplicity1 and the unity1 which it introduces into the phenomena of geology1 would sufficiently justify the application of it to the theory of the earth4 ,as another excellence of this theory1 ,i may1 perhaps1 be allowed to remark1 that it extends its consequences beyond those to which the author of it has himself adverted1 and that it affords1 which no geological theory has yet done1 a satisfactory explanation of the spheroidal figure of the earth4#dj ,footnote #dj3 ,,note ,,xxv4 #acc4 ,yet1 with all these circumstances of originality1 grandeur1 and simplicity in its favour1 with the addition of evidence as demonstrative as the nature of the subject will admit1 this theory has probably many obstacles to overcome1 before it meet the general approbation4 ,the greatness of the objects which it sets before us1 alarms the imagination2 the powers which it supposes to be lodged in the subterraneous regions2 a heat which has subdued the most refractory rocks1 and has melted beds of marble and quartz2 an expansive force1 which has folded up1 or broken the strata1 and raised whole continents from the bottom of the sea2 these are things with which1 however certainly they may be proved1 the mind cannot soon be familiarized4 ,the change and movement also1 which this theory ascribes to all that the senses declare to be most unalterable1 raise up against it the same prejudices which formerly opposed the belief in the true system of the world2 and it affords a curious proof1 how little such prejudices are subject to vary1 that as ,aristarchus1 an ancient follower of that system1 was charged with impiety for moving the everlasting ,vesta from her place1 so ,dr ,hutton1 nearly on the same ground1 has been subjected to the very same accusation4 ,even the length of time which this theory regards as necessary to the revolutions of the globe1 is looked on as belonging to the marvellous2 and man1 who finds himself constrained by the want of time1 or of space1 in almost all his undertakings1 forgets1 that in these1 if in any thing1 the riches of nature reject all limitation4#da ,footnote #da3 ,,note ,,xxvi4 ,the evidence which must be opposed to all these causes of incredulity1 cannot be fully understood without much study and attention4 ,it requires not only a careful examination of particular instances1 but comprehensive views of the whole phenomena of geology2 the comparison of things very remote with one another2 the interpretation of the obscure by the luminous1 and of the doubtful by the decisive appearances4 ,the geologist must not content himself with examining the insulated specimens of his cabinet1 or with pursuing the nice subtleties of mineralogical arrangement2 he must study the relations of fossils1 as they actually exist2 he must follow nature into her wildest and most inaccessible abodes2 and must select1 for the places of his observations1 those points1 from which the variety and gradation of her works can be most extensively and accurately explored4 ,without such an exact and comprehensive survey1 his mind will hardly be prepared to relish the true theory of the earth4 ,natur enim vis atque majestas omnibus momentis fide caret1 si quis modo partes atque non totam complectatur animo4#db ,footnote #db3 ,,plin4 ,hist4 ,nat4 lib4 vii4 ,cap4 i4 #acd4 ,if indeed this theory of the earth is as well founded as we suppose it to be1 the lapse of time must necessarily remove all objections to it1 and the progress of science will only develope its evidence more fully4 ,as it stands at present1 though true1 it must be still imperfect2 and it cannot be doubted1 that the great principles of it1 though established on an immoveable basis1 must yet undergo many modifications1 requiring to be limited1 in one place1 or to be extended1 in another4 ,a work of such variety and extent cannot be carried to perfection by the efforts of an individual4 ,ages may be required to fill up the bold outline which ,dr ,hutton has traced with so masterly a hand2 to detach the parts more completely from the general mass2 to adjust the size and position of the subordinate members2 and to give to the whole piece the exact proportion and true colouring of nature4 ,this1 however1 in length of time1 may be expected from the advancement of science1 and from the mutual assistance which parts of knowledge1 seemingly the most remote1 often afford to one another4 ,not only may the observations of the mineralogist1 in tracts yet unexplored1 complete the enumeration of geological facts2 and the experiments of the chemist1 on substances not yet subjected to his analysis1 afford a more intimate acquaintance with the nature of fossils1 and a measure of the power of those chemical agents to which this theory ascribes such vast effects3 but also1 from other sciences1 less directly connected with the natural history of the earth1 much information may be received4 ,the accurate geographical maps and surveys which are now making2 the foundings2 the obsevations of currents2 the barometrical measurements1 may all combine to ascertain the reality1 and to fix the quantity of those changes which terrestrial bodies continually undergo4 ,every new improvement in science affords the means of delineating more accurately the face of nature as it now exists1 and of transmitting1 to future ages1 an account1 which may be compared with the face of nature as it shall then exist4 ,if1 therefore1 the science of the present times is destined to survive the physical revolutions of the globe1 the ,,huttonian ,,theory may be confirmed by historical record2 and the author of it will be remembered among the illustrious few1 whose systems have been verified by the observations of succeeding ages1 supported by facts unknown to themselves1 and established by the decisions of a tribunal1 slow1 but infallible1 in distinguishing between truth and falsehood4 ,,notes ,,and ,,additions4 ,,notes ,,and ,,additions4 ,,note ,i4 #b4 ,origin of calcareous rocks4 #ace4 ,,it has been asserted1 that ,dr ,hutton went farther than is stated at #b1 and maintained all calcareous matter to be originally of animal formation4 ,this position1 however1 is so far from being laid down by ,dr ,hutton1 that it belongs to an inquiry which he carefully avoided to enter on1 as being altogether beyond the limits of philosophical investigation4 ,he has indeed no where treated of the first origin of any of the earths1 or of any substance whatsoever1 but only of the transformations which bodies have undergone since the present laws of nature were established4 ,he considered this last as all that a science1 built on experiment and observation1 can possibly extend to2 and willingly left1 to more presumptuous inquirers1 the task of carrying their reasonings beyond the boundaries of nature1 and of unfolding the properties of the chaotic fluid1 with as much minuteness of detail1 as if they were describing the circumstances of a chemical process which they had actually witnessed4 ,the idea of calcareous matter which really belongs to the ,huttonian ,theory1 is1 that in all the changes which the terraqueous globe has undergone in past ages1 this matter existed1 as it does now1 either in the form of limestone and marble1 or in the composition of other stones1 or in the state of corals1 shells1 and bones of animals4 ,it may be true1 that there is no particle of calcareous matter1 at present existing on the surface of the earth1 that has not1 at some time1 made a part of an animal body2 but of this we can have no certainty1 nor is it of any importance that we should4 ,it is enough to know1 that the rocks of marble and limestone contain in general marks of having been formed from materials collected at the bottom of the sea2 and of this a single cockle-shell1 or piece of coral1 found included in a rock1 is a sufficient proof with respect to the whole mass of which it makes a part4 ,the principal object which ,dr ,hutton had in view when he spoke of the masses of marble and limestone1 as composed of the calcareous matter of marine bodies1#dc was to prove1 that they had been all formed at the bottom of the sea1 and from materials there deposited4 ,his general conclusion is1 ,that all the strata of the earth1 not only those consisting of such calcareous masses1 but others superincumbent upon these1 have had their origin at the bottom of the sea1 by the collection of sand and gravel1 of shells1 of coralline and crustaceous bodies1 and of earths and clays variously mixed1 or separated and accumulated4 ,this is a general conclusion1 well authenticated by the appearances of nature1 and highly important in the natural history of the earth4#dd ,footnote #dc3 ,theory of the ,earth1 vol4 i4 p4 #bc1 #bd4 ,footnote #dd3 ,theory of the ,earth1 vol4 i4 p4 #bf4 #acf4 ,in his ,geological ,essays1 ,mr ,kirwan says1 that some geologists1 as ,buffon1 and of late ,dr ,hutton1 have excluded calcareous earth from the number of the primeval1 asserting the masses of it we at present behold to proceed from shell-fish4 ,but1 in addition to the unfounded supposition1 that shell-fish1 or any animals1 possess the power of producing any simple earth1 these philosophers should have considered1 that1 before the existence of any fish1 the stony masses that inclose the bason of the sea1 must have existed2 and1 among these1 there is none in which calcareous earth is not found4 ,dr ,hutton endeavours to evade this argument1 by supposing the world we now inhabit to have arisen from the ruins and fragments of an anterior1 without pointing at any original4 ,if we are thus to proceed in infinitum1 ,i shall not pretend to follow him2 but1 if he stops any where1 he will find the same argument equally to occur4#de ,footnote #de3 ,geol4 ,essays1 p4 #ac4 ,the argument here employed would certainly be conclusive against any one1 who1 in disputing about the first origin of things1 should deny that the calcareous is as ancient as any other of the simple earths4 ,but this has nothing to do with ,dr ,hutton's speculations1 which1 as has been just said1 never extended to the first origin of substances1 but were confined entirely to their changes2 so that what he asserts concerning the calcareous rocks1 is no more than that those which we now see have been formed from loose materials1 deposited at the bottom of the sea4 ,it was not therefore in order to evade ,mr ,kirwan's argument1 as the preceding passage would lead us to believe1 that he supposed the world which we now inhabit to have arisen from the ruin and waste of an anterior world2 but it was because this seemed to him a conclusion which necessarily followed from the phenomena of geology1 and it was a conclusion that he had deduced long before he heard of ,mr ,kirwan's objections to his system4 ,instead of an evasion1 therefore1 any one who considers the subject fairly1 will see1 in ,dr ,hutton's reasoning1 nothing but the caution of a philosopher1 who wisely confines his theory within the same limits by which nature has confined his experience and observation4 ,it is nevertheless true1 that ,dr ,hutton has sometimes expressed himself as if he thought that the present calcareous rocks are all composed of animal remains4#df ,this conclusion1 however1 is more general than the facts warrant2 and1 from some incorrectness or ambiguity of language1 is certainly more general than he intended4 ,the idea of calcareous rocks1 on which he argues throughout his whole theory1 is precisely that which is stated in the preceding article4 ,footnote #df3 ,theory of the ,earth1 vol4 i4 p4 #bc4 ,,note ,,ii4 #f4 ,origin of coal4 #acg4 ,the vegetable origin of coal seems to be sufficiently proved by the reasoning in #e4 and #f42 and that reasoning will appear still more satisfactory1 from what is said at #bh4 and #bi41 concerning the consolidation of this fossil4 ,dr ,hutton has treated both of the matter of coal and of its consolidation4 ,part4 ,i4 ,chap4 #h41 of his ,theory of the ,earth #dg4 ,footnote #dg3 ,vol4 i4 p4 #eeh1 c4 ,the notion1 however1 that coal is of vegetable origin1 is not peculiar to this theory1 but has been for some time the prevailing opinion4 ,buffon supposes this mineral to be formed from vegetable and animal substances1 the oil and fat of which have been converted into bitumen by the action of acids4#dh ,a fundamental mistake1 however1 is committed by this author1 and by ,m4 ,,gensanne1 7author of the natural history of ,languedoc17 on whose observations he greatly relies1 in considering coal as consisting of bitumen united to earth1 thus omitting the only ingredient essential to coal1 namely the carbon or charcoal4 ,this may truly be considered as the essential part1 because coal may exist without bitumen1 as in the instance of blind coal1 but not without charcoal4 ,footnote #dh3 ,hist4 ,nat4 des ,mineraux4 tom4 i4 p4 #dbi1 #dto edit4 ,another theory of coal1 very analogous to ,dr ,hutton's1 is that of ,,arduino1 professor of mineralogy at ,venice1 in which he supposes it formed from vegetable and animal remains from the land and sea1 but chiefly from the latter4#di ,this theory of coal is contained in ,dr ,hutton's1 in which the animal and vegetable remains must be supposed to come both from the earth and the sea4 ,it seems to be without any good reason that ,arduino considers the sea as the chief source of these materials4 ,his remarks1 however1 are very ingenious1 and deserving of attention4 ,footnote #di3 ,saggio ,fisico-mineralogico del ,sig4 ,giov4 ,arduino2 ,atti di ,siena1 tom4 v4 p4 #bbh1 #bha1 c4 ,these accounts of the origin of coal are all nearly the same2 it is in what relates to the distinction between the common coal1 in which there is no ligneous structure1 and those varieties of it in which that structure is apparent1 and again in explaining the consolidation of both1 that the theory laid down here is peculiar4 #ach4 ,some other mineralogists refer one of the ingredients of coal to the vegetable kingdom1 but not the other4 ,unable to resist the conviction which arises from the fibrous structure of parts of strata1 and even entire strata of coal1 they have supposed1 that wood1 which had been somehow buried in the earth1 or perhaps deposited at the bottom of the sea1 had become impregnated with bitumen1 which last1 however1 they consider as of mineral origin4 ,this appears to be the opinion of ,lehman2 and also of some very late writers4 ,there seems1 however1 to be hardly less reason for referring the origin of one part of coal to the vegetable or animal kingdom than another4 ,the two last are certainly capable of furnishing both the carbonic and bituminous parts2 and therefore1 to derive these from different sources1 is at least a very unnecessary complication of hypotheses4 #aci4 ,another explanation of coal1 very different from any of the preceding1 has lately been advanced and set up in opposition to the ,huttonian ,theory4 ,mr ,kirwan1#ej the only mineralogist1 ,i believe1 who has attempted to derive both the carbonic and bituminous matter of coal from the mineral kingdom1 distinguishes between wood coal and mineral coal1 and gives a theory entirely new of the formation of the latter4 ,wood coal is that in which the ligneous structure is so apparent1 as to leave no doubt of its vegetable origin2 mineral coal is that in which no such structure can be discovered1 and is the same which ,dr ,hutton derives from the vegetable juices1 and other remains1 comminuted1 dispersed1 carried into the sea1 and there precipitated1 so as to unite with different proportions of earth1 and to become afterwards mineralized4 ,footnote #ej3 ,geol4 ,essays1 essay vii4 p4 #bij4 ,these two species of coal1 which the ,huttonian theory considers as gradations of the same substance1 ,mr ,kirwan regards as perfectly distinct1 constituting two minerals1 of an origin and formation entirely different4 ,he therefore endeavours to ascertain the distinguishing characters of each1 considered geologically4 #adj4 ,but here the leading distinction1 implied in all the rest1 that the two kinds of coal are never found in the same bed1 but always in different situations1 and with different laws of stratification1 is expressly contradicted by matter of fact4 ,coal1 as is said above1 with its ligneous texture quite apparent1 and coal with no such structure visible1 are often found in the same seam1 are brought up from the same mine1 and united in the same specimen4 ,i have a specimen from a bed of coal1 in the ,isle of ,sky1 found under a basaltic rock1 consisting of a ligneous part1 which graduates into one in which there is no vestige of a fibrous texture1 and in which the surface is smooth and glossy1 with a fracture almost vitreous4 ,the upper part of the specimen is therefore perfect wood coal1 and the under part perfect mineral-coal1 in the language of ,mr ,kirwan2 at the same time that the transition from the one to the other is made by insensible degrees4 ,this specimen1 were it perfectly solitary1 is sufficient to prove the identity of the two species of coal we are now speaking of1 and to show1 that the difference between them is accidental1 not essential4 ,the specimen1 however1 is far from being solitary2 the number of similar appearances is so great1 as hardly to have escaped the observation of any mineralogist4 ,mr ,kirwan admits1 that wood coal is often found under basaltes2#ea but what is essential to be remarked is1 that1 in this instance1 we have both the wood coal and the common mineral-coal1 lying under that rock1 and the one passing gradually into the other ,it appears1 indeed1 that many of the facts which ,mr ,kirwan produces1 in treating of what he calls carboniferous soils1 are quite inconsistent with the distinction he would make between wood-coal and mineral coal4#eb ,footnote #ea3 ,geol4 ,essays1 p4 #caj4 ,footnote #eb3 ,ibid4 p4 #caa4 #ada4 ,it is1 however1 true1 that there are instances in which the wood coal1 or fossil wood1 as it is usually called1 forms entire beds1 quite unconnected with the ordinary coal1 and stratified in some respects differently4 ,such is the ,bovey coal in ,devonshire1 the wood-coal in the north of ,ireland1 and perhaps the ,surturbrandt of ,iceland4 ,with respect to the ,bovey coal1 it does by no means answer to one of ,mr ,kirwan's remarks1 viz4 that late observations have ascertained1 that no such parallelism of the beds1 as in mineral coal1 nor even any distinct number of strata is found4 ,in the ,bovey coal1 the number of strata is very well defined1 by beds of clay regularly interposed2 but as to the extent of these beds1 the coal having been worked only at one place1 and by an open pit1 without any extensive subterraneous excavation1 nothing is known with certainty4 ,in the ,bovey coal too1 ,i must observe1 though its beds have the ligneous structure very distinct1 the clay interposed between these beds1 which is but little indurated1 contains a great deal of coaly matter1 in the form of thin flakes1 interspersed through it4 ,so far as ,i know1 there are no mineral reins nor shifts1 nor any bed of indurated stone1 that accompany this coal2 so that1 though one can not doubt of its vegetable origin1 some doubt may be entertained concerning the nature of the mineralizing operations1 to which it has been subjected ,the consideration of these1 however1 does not belong to the present argument2 and the peculiarities of this semi-mineralized coal1 as it may be called1 have nothing to do with the general question1 whether wood coal and mineral coal are the same substance2 about which question1 if the gradations are properly considered1 ,i think1 no reasonable doubt can remain4 #adb4 ,one of ,mr ,kirwan's objections to the vegetable origin of coal1 is founded on this fact1 that there is1 in the museum at ,florence1 a cellular sandstone1 the cells of which are filled with genuine mineral coal4 ,could this 7adds he7 have been originally wood8#ec ,the answer to the interrogatory proposed here as a reductio ad absurdum1 is1 that most undoubtedly it may have been wood4 ,sandstone with charred wood1 that is1 with wood coal in it1 is not an uncommon phenomenon in coal countries4 ,i have seen a specimen of this kind from the ,hales ,quarry1 near ,edinburgh1 consisting of a piece of charred wood1 imbedded in sandstone2 the wood was much altered1 but the remains of its fibrous structure were distinctly visible4 ,this affords a perfect commentary on the specimen in the ,florence cabinet4 ,footnote #ec3 ,geol4 ,essays1 p4 #cba4 #adc4 ,if then it be granted1 as ,i think it must1 that the two kinds of coal we have been speaking of are of the same origin1 it is not very necessary to enter on a refutation of ,mr ,kirwan's theory with respect to either of them4 ,his account of the formation of mineral coal1 however1 is so singular1 that it cannot be passed over without remark4 ,mr ,kirwan supposes1 #amo1 ,that natural carbon was originally contained in many mountains of the granite and porphyritic order1 and also in siliceous schistus2 and might1 by disintegration and decomposition1 be separated from the stony particles4 #b;do1 ,that both petrol and carbon are often contained in trap1 since hornblende1 which has lately been found to contain carbon1 very frequently enters into its composition4 ,my opinion 7adds he7 is1 that coal mines1 or strata of coal1 as well as the mountains in which they are found1 owe their origin to the disintegration of primeval mountains1 either now totally destroyed1 or whose height and bulk1 in consequence of such disintegration1 are considerably lessened2 and that these rocks1 anciently destroyed1 contained most probably a far larger proportion of carbon and petrol than those of the same denomination now contain1 since their disintegration took place at so early a period4#ed ,footnote #ed3 ,geol4 ,essays1 p4 #cbh1 c4 ,by the decomposition of these mountains1 the feldspar and hornblende were converted into clay2 the bituminous particles1 thus set free1 reunited1 and were absorbed1 partly by the argil1 but chiefly by the carbonaceous matter1 with which they have the greatest affinity4 ,the carbonic and bituminous particles1 thus united1 being difficultly miscible with water1 and specifically heavier1 sunk through the moist1 pulpy1 incoherent argillaceous masses1 and formed the lowest stratum1 c4 ,such is ,mr ,kirwan's theory of the formation of coal1 and nobody ,i think will dispute the originality of it4 #add4 ,to enter on a formal refutation of an opinion so loaded with objections1 would be a task as irksome as unnecessary4 ,a few observations will suffice4 ,the notion of the great degradation of mountains1 involved in this hypothesis1 is the part of it to which ,i am least disposed to object4 ,but ,i cannot help reminding ,mr ,kirwan1 that the effects of waste are not supposed less in this1 than in ,dr ,hutton's theory2 and that he has assumed the very principle1 of which that theory makes so much use1 though he has reserved to himself1 as it should seem1 the right of denying it1 when it does not accord with his system4 ,it is indeed worth while to compare what is said concerning the degradation of mountains1 in the above quotations1 and still more fully in the book itself1 with what is advanced concerning their indestructibility1 in another passage of the same volume3#ee ,footnote #ee3 ,page #dcf4 ,all mountains are not subject to decay2 for instance1 scarce any of those that consist of red granite4 ,the stone of which the ,runic rocks are formed1 have withstood decomposition for two thousand years1 as their characters evince1 c4 ,basaltic pillars1 in general1 bid defiance to decay1 c4 ,he goes on to deny every step of the degradation of land1 by which it is wasted1 carried into the sea1 and spread out over its bottom1 though all these are necessary postulata in his theory of the formation of coal4 ,one can be at no loss about estimating the value of a system1 in which such gross inconsistencies make a necessary part4 #ade4 ,the quantity of hornblende and siliceous schistus1 necessary to be decomposed1 in order to produce the coal strata presently existing1 is enormous1 and would lead to an estimate of what is worn away from the primeval mountains1 far exceeding any thing that ,dr ,hutton has supposed4 ,it is true1 that ,mr ,kirwan1 never at all embarrassed about preserving a similitude between nature as she is now1 and as she was heretofore1 lays it down1 that the part of the primeval mountains which is worn away1 contained much more carbon than the part which is left behind4 ,this1 however1 is an arbitrary supposition2 and since1 in this system1 such suppositions are so easily admitted1 why may we not conceive1 in the primeval mountains1 a more copious source of carbonic matter than hornblende or siliceous schistus8 ,we have but to imagine1 that the diamond existed among these mountains in such abundance1 as to constitute large rocks4 ,this stone being made up of pure1 or highly concentrated carbon1 the adamantine summits of a single ridge1 by their decomposition1 might afford a carbonic basis1 sufficient for the coal beds of all the surrounding plains4 #adf4 ,we may also object to ,mr ,kirwan1 that the siliceous part of the mountains has not been chemically dissolved2 it has been only abraded and worn away4 ,mechanical action has reduced the quartz to gravel and sand1 but has not produced on it any chemical change4 ,the carbon1 therefore1 could not be let loose4 ,experiment1 indeed1 might be employed1 to determine whether the siliceous matter of the secondary1 and of the primary strata contains this substance in the same proportion4 ,again1 a more fatal symptom can hardly be imagined in any theory1 than that1 when the circumstances of the phenomena to be explained are a little changed1 the theory is under the necessity of changing a great deal4 ,now1 this is what happens to ,mr ,kirwan's theory1 in the attempt made to explain by it the stratum of coal described in the ,annales de ,chimie1#ef as cutting a mountain of argillaceous strata in two1 at about three-fourths of its height4 ,this stratum1 ,mr ,kirwan says1 must have been formed by transudation from the superior part of the mountain1#eg ,besides that this is a gratuitous supposition of a thing1 without example1 it involves in it an absurdity1 which becomes evident the moment the question is asked1 ,what occupied the place of the coal-bed before the transudation from the upper part of the mountain8 ,has the liquid coal1 as it percolated through the upper strata1 expelled any substance from the place it now occupies8 or has it been powerful enough to raise up1 or to float1 as it were1 the upper part of the mountain8 ,footnote #ef3 ,tom4 xi4 p4 #bgb4 ,footnote #eg3 ,geol4 ,essays1 p4 #cch4 ,the situation of this bed of coal is not singular1 and its formation is easily explained on ,dr ,hutton's theory4 ,it is part of a stratum of coal1 which has been deposited1 like all others1 at the bottom of the sea2 from whence certain causes1 of very general operation1 have raised it up1 together with the attending strata3 these strata have since been all cut down1 and worn away by the operations of the surface2 and the mountain1 with the coal stratum in the middle of it1 is a part of them which has been left behind4 ,there is no wonder1 that a coal stratum should be found alternating with others1 in a mountain1 any more than in the bowels of the earth1 and no more need of a separate explanation4#eh ,footnote #eh3 ,this stratum of coal1 which is described by ,,hassenfratz1 is remarkable for being in a mountain which rests immediately on primary schistus and granite4 #adg4 ,after all1 it may be asked1 for what purpose is it that so many incongruous and ill supported hypotheses are thus piled on one another8 is it only to avoid ascribing the carbonic and bituminous matter of coal to a substance in which we know with certainty that such matter resides in great abundance1 in order to derive it from other substances1 in which a subtle analysis has shown1 that it exists in a very small proportion8 ,such reasoning is so great a trespass on every principle of common sense1 not to say of sound philosophy1 that1 to bestow any time on the refutation of it1 is1 in some degree1 to fall under the same censure4 ,,note ,,iii4 #g4 ,primitive mountains4 #adh4 ,the enumeration of the different kinds of primary schistus1 at #g1 is not proposed as at all complete4 ,it will be less defective1 however1 if we add to it talcose schistus1 and lapis ollaris or potstone4#ei ,footnote #ei3 ,kirwan's ,mineralogy1 vol4 i4 p4 #aee4 #adi4 ,the rocks called here by the name of primary1 were first distinguished1 as forming the basis of all the great chains of mountains1 and as constituting a separate division of the mineral kingdom1 by ,j4 ,g4 ,,lehman1 director of the ,prussian mines4 ,see his work1 intituled1 ,essai d'une ,histoire ,naturelle des ,couches de la ,terre4#fj ,these rocks were regarded by ,lehman as parts of the original nucleus of the globe1 which had undergone no alteration1 but remained now such as they were at first created2 and1 agreeably to this supposition1 he bestowed on them1 and on the mountains composed of them1 the name of primitive4 ,he remarks1 nevertheless1 their distribution into beds1 either perpendicular to the horizon1 or highly inclined1 and the super-position of the secondary and horizontal strata4 ,however mineralogists may now differ in their theories from ,lehman1 they must consider this distinction as a great step in the science of geology1 and very material to the right arrangement of the natural history of the earth4 ,footnote #fj3 ,tom4 iii4 p4 #bci1 c4 ,the ,french translation is in #agei1 but the original preface is dated at ,berlin1 #agef4 #aej4 ,several mineralogists have agreed with him in the supposition1 that these rocks are a part of the original structure of the globe1 and prior to all organized matter4 ,of this number is ,,pallas2#fa and also ,,de ,,luc1 who applies the term primordial to the rocks in question1 and considers them as neither stratified nor formed by water4#fb ,in his subsequent writings1 however1 he admits their formation from aqueous deposition1 as the ,neptunists do in general1 but holds them to be more ancient than organized bodies4 ,footnote #fa3 ,observations sur la ,formation des ,montagnes4 ,footnote #fb3 ,lettres ,phys4 ,sur l',histoire de la ,terre1 tom4 ii4 p4 #bjf4 #aea4 ,,pini1 professor of natural history at ,milan1 has denied the stratification of primitive mountains1 in a memoir on the mineralogy of ,st ,gothard1 and in another on the revolutions of the globe4#fc ,his reasonings are opposed by ,,saussure1#fd and are certainly1 in many respects1 very open to attack4 ,they proceed on a comparison between the division of rocks1 by what is called the planes of their stratification1 and their division by transverse fissures3 two things1 which he thinks so much alike1 that they ought not to be referred to different causes2 and1 as the one cannot be regarded as the effect of aqueous deposition1 so neither should the other4 ,this is a very fallacious argument1 because it confounds two things that are essentially different2 and1 instead of inquiring about a matter of fact1 inquires about its cause4 ,the truth is1 that the dispute has arisen from not distinguishing the granite from the schistus mountains1 and from involving both under the name of primitive4 ,m4 ,pini seems to be in the right1 when he holds the granite of ,st ,gothard to be unstratified2 but it is without any good reason1 that he would extend the same conclusion to the schistus of that mountain4 ,,charpentier1 and ,saussure1 in his last two volumes1 contend even for the stratification of granite4#fe ,footnote #fc3 ,memoria sulle ,rivoluzioni del ,globo ,terrestre2 ,memorie della ,societa ,italiana1 tom4 v4 p4 #bbb1 c4 ,footnote #fd3 ,voyages aux ,alpes1 tom4 iv4 #ahha4 ,footnote #fe3 ,see ,,note ,,xv4 on ,granite4 ,as the consent1 if not universal1 is very general for the stratification of the primary schistus1 and the fact itself abundantly obvious1 in almost all the instances ,i have ever met with1 ,i have not considered it as necessary to enter here into any argument on this subject4 ,,note ,,iv4 #h4 ,primary strata not primitive4 #aeb4 ,an account of the facts referred to #h1 may be found in ,hutton's ,theory1 vol4 i4 p4 #ccb1 c4 ,to what is there said1 of the shells contained in the primary limestone of ,cumberland1 ,i must add1 that ,i have since had an opportunity of verifying the conjecture1 that the limestone rock1 in which the shells were found1 near the head of ,coniston ,lake1 is part of the same body of strata1 where shells were found1 in a quarry between ,ambleside and ,low-wood4 ,the limestone of that quarry contains several marine objects2 it is in strata declining about #aj from the perpendicular1 toward the ,s4 ,e41 and forms a belt1 stretching across the country from ,n4 ,e4 to ,s4 ,w4 ,in a quarry where the argillaceous schistus1 on the south side of this limestone belt1 is worked for pavement1 are impressions of what ,i think may safely be accounted marine objects2 they have the form of shells1 are much indurated1 and full of pyrites4 ,they seem to be of the same kind with the impressions said to be found in a slate quarry1 near the village of ,mat in ,switzerland4#ff ,footnote #ff3 ,hutton's ,theory1 vol4 i4 p4 #cbg4 ,another spot1 affording instances of shells in primary limestone1 is in ,devonshire4 ,on the sea shore on the east side of ,plymouth ,dock1 opposite to ,stonehouse1 ,i found a specimen of schistose micaceous limestone1 containing a shell of the bivalve kind3 it was struck off from the solid rock1 and cannot possibly be considered as an adventitious fossil4 ,now1 no rocks can be more decided primary than those about ,plymouth4 ,they consist of calcareous strata1 in the form either of marble or micaceous limestone1 alternating with varieties of the same schistus1 which prevails through ,cornwall to the west1 and extends eastward into ,dartmoor1 and on the sea-coast1 as far as the ,berry-head4 ,these all intersect the horizontal plane1 in a line from east to west nearly2 they are very erect1 those at ,plymouth being elevated to the north4 ,though1 therefore1 the remains of marine animals are not frequent among the primary rocks1 they are not excluded from them2 and hence the existence of shell-fish and zoophytes1 is clearly proved to be anterior to the formation even of those parts of the present land which are justly accounted the most ancient4 #aec4 ,the rocks which contain sand or gravel1 which are of a granulated texture1 must also be considered as carrying in themselves a testimony of the most unequivocal kind1 of their being derived from the detritus and waste of former rocks4 ,now1 the fact stated in the text1 concerning sand found in schistus1 most justly accounted primary1 might be exemplified by actual reference to many spots on the earth's surface4 ,a few such will be sufficient in this place4 ,st ,gothard is a central point1 in one of the greatest tracts of primary mountains on the face of the earth1 yet arenaceous strata are found in its vicinity4 ,between ,ayrolo and the ,hospice of ,st ,gothard1 ,saussure found a rock1 composed of an arenaceous or granular paste1 including in it hornblende and garnets4 ,he is somewhat unwilling to give the name gres to this stone1 which ,m4 ,besson had done2 but he nevertheless describes it as having a granulated structure4#fg ,footnote #fg3 ,voyages aux ,alpes1 tom4 iv4 #ahbb4 ,among the most indurated rocks that compose the mountains of this island1 many are arenaceous4 ,thus1 on the western coast of ,scotland1 the great body of high and rugged mountains on the shores of ,arafaig1 c4 from ,ardnamurchan to ,glenelg1 consists1 in a great measure1 of a granitic sandstone1 in vertical beds4 ,this stone sometimes occupies great tracts2 at other times it is alternated with the micaceous1 or other varieties of primary schistus2 it occurs1 likewise1 in several of the islands1 and is a fossil which we hardly find described or named by the writers on mineralogy4 ,much1 also1 of a highly indurated1 but granulated quartz1 is found in several places in ,scotland1 in beds or strata1 alternated with the common schistus of the mountains4 ,remarkable instances of this may be seen on the north side of the ferry of ,balachulish1 and again on the sea-shore at ,cullen4 ,at the latter1 the strata are remarkably regular1 alternating with different species of schistus4 ,at the former1 the quartz is so pure1 that the stone has been mistaken for marble4 ,these examples are perhaps sufficient2 but ,i must add1 that in the micaceous and talcose schisti themselves1 thin layers of sand are often found1 interposed between the layers of mica or talc4 ,i have a specimen1 from the summit of one of the highest of the ,grampian mountains1 where the thin plates1 of a talcky or asbestine substance1 are separated by layers of a very fine quartzy sand1 not much consolidated4 ,the mountain from which it was brought1 consists of vertical strata1 much intersected by quartz veins4 ,it is impossible to doubt1 in this instance1 that the thin plates of the one substance1 and the small grains of the other1 were deposited together at the bottom of the sea1 and that they were alike produced from the degradation of rocks1 more ancient than any which now exist4 #aed4 ,in the ,neptunian system1 as improved by ,,werner1 an attempt is made to take off the force of such instances as are produced in #h1 #i1 and #aeb1 c4 by distinguishing rocks1 as to their formation1 into three different orders1 the primitive1 the intermediate1 and the secondary1 or1 to speak more properly1 into primary1 secondary1 and tertiary4 ,the same mineralogist distinguishes1 among the materials of these rocks1 between what he terms chemical and mechanical deposits4 ,by mechanical deposits1 are understood sand1 gravel1 and whatever bears the mark of fracture and attrition2 by chemical deposits1 those which are regularly crystallized1 or which have a tendency to crystallization1 and in which the action of mechanical causes cannot be traced4 ,this distinction is founded in nature1 and proceeds on real and palpable differences2 but the application made of it to the three kinds of strata just enumerated1 seems by no means entitled to the same praise4 ,the primitive rocks contain1 it is said1 none but chemical deposits1 and are entirely composed of them3 the intermediate contain a mixture of both1 and also some vestiges of organized bodies3 the secondary consist almost entirely of the mechanical1 or of the remains of such bodies1 with little of the chemical4 ,the first of these1 then1 are held to contain no mark or vestige whatsoever of any thing more ancient than themselves1 and are1 in the strictest sense1 primeval1 or formed of the first materials1 deposited by the immense ocean which originally encompassed the globe4 ,after them were formed the intermediate1 mostly consisting of chemical deposits1 but containing also some animal remains1 and some spoils from the land1 subjected to the various kinds of destruction1 which even then made a part of the order of nature4 ,these rocks1 it is alleged1 are chiefly argillaceous1 are less indurated than the primary1 and not intersected by veins of quartz4 ,the secondary were formed from the remains of the other two1 and contain more mechanical deposits than any other4 ,this sketch of what ,i understand to be ,werner's opinion concerning the different formation of the strata1 is chiefly taken from a view of his system1 in the ,journal de ,physique for #ahjj4 #aee4 ,the main objection to the distinction here made between the primary and the intermediate strata1 is founded on the facts that have been just stated4 ,the sandstone of ,st ,gothard is from a country having every character of a primary one in the highest perfection4 ,the instances ,i have mentioned from the ,highlands of ,scotland1 are from mountains1 less elevated indeed than the ,alps1 but where the rock is micaceous1 talcose1 or siliceous1 in planes erect to the horizon1 and intersected by veins' of quartz4 ,the shells from ,plymouth are from a rock1 that ,werner would1 ,i think1 admit to be truly primitive4 ,those from the lakes1 also1 are from the centre of a country1 occupied by porphyry1 schorl1 hornstone-schistus1 and many others1 about the order of which there can be no dispute4 ,it is true1 that in this tract there are argillaceous strata1 of the kind that might be accounted intermediate1 were they not interposed among those that are certainly primary2 and this very intermixture shows1 how little foundation there is for the distinction attempted to be made between the formation of the one and of the other4 ,if there is any principle in mineralogy1 which may be considered as perfectly ascertained1 it is1 that rocks similarly stratified1 and alternated with one another1 are of the same formation4 ,hence we conclude1 that there is no order of strata yet known1 that does not contain proofs of the existence of more ancient strata4 ,we see nothing1 in the strict sense1 primitive4 ,it must be understood1 that what is here said has no reference to granite1 which ,i do not consider as a stratified rock1 and in which neither the remains of organized bodies1 nor sand1 have ,i believe been ever found2 though some instances will be hereafter mentioned1 where granite contains fragments of other stone1 viz4 of different kinds of primary schistus4 ,to the instances of sand involved in primary schistus1 ,i might have added many from the rocks of that order on the coast of ,berwickshire1 of which mention is so often made in these ,illustrations2 but ,i wished to draw the evidence from those rocks that are most unequivocally primary1 and to which the ,wernerian distinction of intermediate could not possibly be applied4 ,if any one assert1 as ,m4 ,de ,luc has done1 that sand is a chemical deposit1 a certain mode of crystallization which quartz sometimes assumes1 let him draw the line which separates sand from gravel2 and let him explain why quartz1 in the form of sand1 is not found in mineral veins1 in granite1 nor in basaltes1 that is1 in none of the situations where the appearances of crystallization are most general and best ascertained4 ,,note ,v4 #aj4 ,transportation of the materials of the strata4 #aef4 ,the great transportation or travelling of the materials of the strata1 supposed by ,dr ,hutton1 has been treated as absurd by some of his opponents1 particularly ,de ,luc and ,kirwan4 ,these philosophers seem not to have observed1 that their own system1 and indeed every system which derives the secondary strata from the primary1 involves a transportation of materials1 hardly less than is supposed in the ,huttonian theory1 and a degradation of the primeval mountains1 in many instances much greater4 ,to form some notion of this degradation1 it must be recollected1 that the primeval mountains1 which furnished the materials of the secondary strata in the plains1 cannot have stood in the place now occupied by these plains4 ,this is obvious2 and therefore we must necessarily regard the secondary strata as derived from the primitive mountains which are the nearest to them1 and of which a part still remains4 ,this part is sufficient to define the base of the original mountains2 and the quantity of the secondary strata which surround them may help us to make some estimate of their height4 ,let us take1 for instance1 the extensive tract of secondary country about ,newcastle1 where coal mines have been sunk through a succession of secondary strata1 to the depth of more than a thousand feet4 ,this secondary country may be considered as comprehending almost the whole of the counties of ,northumberland and ,durham1 and probably as extending very far under the part of the ,german ,ocean which washes their coasts2 and the whole strata composing it must be derived1 on the hypothesis we are now considering1 from the ,cheviot ,hills1 on one side1 and from those in the high parts of ,westmoreland and ,cumberland on the other1 comprehending the ,alston-,moor ,hills1 and the large group of primary mountains1 so well known from the sublime and romantic scenery of the ,lakes4 ,now1 the mountains which stood on this base1 had not only to supply the materials for the tract already mentioned1 on the east1 but had also their contingent to furnish to the plains on the west and north2 the ,cheviots to ,roxburghshire and ,berwickshire2 the ,northumberland mountains to the coal strata about ,whitehaven1 and along the sea coast to ,lancashire4 ,on the whole1 we shall not exceed the truth1 if we suppose1 that the secondary strata1 at the feet of the above mountains1 are six or seven times more extensive than the base of the mountainous tract4 ,if then we take the medium depth of these secondary strata to be one thousand feet1 it is evident1 that the mass of stone which composes them1 if it were placed on the same base with the primitive mountains1 would reach to the height of six thousand feet4 ,this is supposing the mass to preserve the breadth of its base uniformly to the summit2 but if it be supposed to taper1 as mountains usually do1 we must multiply this six thousand by three1 in order to have the height of these primeval mountains1 which1 therefore1 were originally elevated not less than eighteen thousand feet2 in height1 therefore1 they once rivalled the ,cordilleras1 and are now but poorly represented by the hills of ,skidaw and ,helvellyn4 ,it were easy to show1 that this estimate is still below the result that strictly follows from the ,neptunian hypothesis2 but it is unnecessary to proceed further1 than to prove1 that the principle of the degradation of mountains1 is involved in that hypothesis to an excessive and improbable degree2 and that the supporters of it1 have either been guilty of the inconsistency of refusing to ,dr ,hutton the moderate use of a principle1 which they themselves employ in its utmost extent1 or of not having sufficiently adverted to the consequences of their own system4 #aeg4 ,the formation of secondary strata from the degradation of the contiguous mountains1 on close examination1 is subject to many other difficulties of the same kind4 ,mountains of secondary strata1 and nearly horizontal1 are found in this island of the height of three thousand feet4 ,such are ,ingleborough1 ,wharnside1 and perhaps some others on the west of ,yorkshire4 ,the whole chain1 indeed1 for secondary mountains1 is of great elevation4 ,the strata are of limestone1 and of a very coarse-grained sandstone1 alternating with it4 ,no mountains can more clearly point out1 that the strata of which they consist were once continued quite across the vallies which now separate them2 and hence1 if the materials of those strata were indeed furnished from any contiguous primitive mountains1 the latter must have been1 out of all proportion1 higher than any mountains now in ,britain4 #aeh4 ,thus1 a great degradation of the primitive mountains1 and of course a great travelling of their materials1 is proved to make a necessary part of the ,neptunian theory4 ,the extent of this travelling or transportation may be rendered more evident1 if we apply a similar mode of reasoning to larger portions of the globe4 ,the north-west of ,europe furnishes us an instance of a very extensive tract of secondary country1 comprehending the greater part of ,britain1 the whole of ,flanders and ,holland1 part of ,germany1 the northern provinces of ,france1 and probably the bed of the ,german ,ocean1 at least for a great extent4 ,within this circle almost all is secondary1 and on the sides of it all round are placed ridges or groups of primitive mountains1 namely the mountains of ,auvergne1 at least in part1 and going round by the east1 the ,alps1 the ,vosges1 the ,hartz1 the ,highlands and ,western ,islands of ,scotland1 the hilly countries of ,cumberland1 ,wales1 and ,cornwall4 ,this zone of primitive mountains1 on the supposition of the ,neptunists1 must have risen up in the form of islands in the great ocean1 that originally covered the earth1 forming a kind of circular ,archipelago1 including in its bosom a sea1 which was from seven to five hundred miles in diameter4 ,over the whole of this extent1 the detritus of the above mountains must have been carried1 in order to form the flat interjacent countries which are now exposed to our view4 ,such then1 even on their own supposition1 is the extent to which the ,neptunists must admit that the materials of the primeval mountains were transported by the ocean4 #aei4 ,this transportation of materials1 may not be so great as that which is involved in ,dr ,hutton's theory1 but is such as should make the enemies of his system consider1 how nearly the principles they must introduce1 agree with those that they would reject4 ,this is one fact1 out of many1 which shows1 that there is at present a much nearer agreement between the systems of geology1 than between their authors4 #afj4 ,to these facts1 demonstrating the great transportation of fossils in some former conditions of the globe1 we may add another1 recognised by all mineralogists4 ,the animal exuvi contained in limestone and marble1 are often known to belong to seas1 extremely remote from the countries where they are now found4 ,in the chalk-beds of ,england1 in the limestones of ,france1 a great proportion of the petrifactions belong to the tropical seas1 and appear to have been brought from the vicinity of the equator4 ,buffon observes1 that of the fossil shells found in ,france1 it has been disputed1 whether the foreign are not more numerous than the native2 and1 though he is himself of opinion that they are not1 it is evident that they must bear a considerable proportion to the whole4#fh ,in the petrifactions of ,monte ,bolca1 near ,verona1 where the impressions of fish are preserved between the lamin of a calcareous schistus1 one hundred and five different species have been enumerated1 of which thirty-nine are from the ,asiatic seas1 three from the ,african1 eighteen from those of ,south1 and eleven from those of ,north ,america4#fi ,similar observations have been made on the marine plants1 and the impressions of vegetables1 found in rocks1 in different parts of ,europe4 ,at ,st ,chaumont1 near ,lyons1 is found an argillaceous schistus1 covering a bed of coal1 every lamina of which is marked with the impressions of the stem1 leaf1 or other part of some plant2 and it happens1 says ,m4 ,,fontenelle1 by an unaccountable destination of nature1 that not one of these plants is a native of ,france4 ,they are all ferns of different species1 peculiar to the ,east ,indies1 or the warmer climates of ,america4 ,here also was found the fruit of a tree1 which grows only on the coasts of ,malabar and ,coromandel4#gj ,footnote #fh3 ,buffon1 ,thorie de la ,terre1 art4 #h4 ,footnote #fi3 ,saussure1 ,voyages aux ,alpes1 tom4 iii4 #aece4 ,footnote #gj3 ,mm4 ,de l',acad4 ,des ,sciences1 #agah1 p4 #c and #bhg2 and #agba1 p4 #hi1 c4 ,the same holds of the bodies of amphibious animals which now make a part of the fossil kingdom4 ,the head and the bones of crocodiles have been found in the island of ,shepey1 at the mouth of the ,thames2 and the remains of an animal of the same species1 but of a variety now peculiar to the ,ganges1 have been discovered in the alum rocks on the coast of ,yorkshire4#ga ,these proofs of the transportation of materials by the sea1 have the advantage of involving nothing hypothetical1 and of being equally addressed to the geologists of every persuasion4 ,footnote #ga3 ,phil4 ,trans4 vol4 l4 p4 #fhh4 ,,camper denies that the remains here mentioned belong to the crocodile1 or any amphibious animal1 and refers them to the balna4 ,he passes the same judgment on those fossil bones from ,st ,peter's ,mount1 near ,maestricht1 which have been supposed to belong to the crocodile2 he looks on them as belonging to whales1 though of an unknown species4 ,in this ,mount1 so famous for its petrifactions1 he finds many specimens of bones1 which he thinks belong to the turtle4 ,phil4 ,trans4 vol lxxvi4 p4 #ddc4 ,the opinion of an author1 so well skilled in comparative anatomy1 must be regarded as of great weight3 if it takes from our argument in one part1 it adds to it in another1 and the acquisition of the turtle makes up abundantly for the loss of the crocodile4 ,on this subject ,i cannot help observing1 that the accurate comparison of the animal exuvi of the mineral kingdom1 with their living archetypes1 is not merely a curious inquiry1 but is one that may lead to important consequences1 concerning the nature and direction of the forces which have changed1 and are continually changing1 the surface of the earth4 #afa4 ,these remarks ,i have thought it proper to add to the proofs of the composition of the present from former strata1 in order to show1 that the great transportation of materials involved in that supposition1 is not only conformable to the hypothesis of the ,neptunists concerning the secondary strata1 but is also proved by the most direct evidence1 independently of all hypothesis4 ,all this reasoning regards the ancient state of the globe4 ,whether such a travelling of stony bodies makes a part of the system now actually carrying on1 will be considered in another place4#gb ,footnote #gb3 ,see ,,note ,,xix4 ,,note ,,vi4 #ac4 ,mr ,kirwan's notion of precipitation4 #afb4 ,the ,neptunist who has provided the means of dissolving the materials of the strata1 has only performed half his work1 and must find it a task of equal difficulty to force this powerful menstruum to part with its solution4 ,mr ,kirwan1 aware in some degree of this difficulty1 has attempted to obviate it in a very singular way4 ,first1 he ascribes the solution of all substances in water1 or in what he calls the chaotic fluid1 to their being finely pulverised1 or created in a state of the most minute division4 ,next1 as to the deposition1 the solvent being1 as he acknowledges1 very insufficient in quantity1 the precipitation took place1 7he says17 on that account the more rapidly4 ,if he means by this to say1 that a precipitation without solution would take place the sooner the more inadequate the menstruum was to dissolve the whole1 the proposition may be true2 but will be of no use to explain the crystallization of minerals1 7the very object he has in view17 because to crystallization1 it is not a bare subsidence of particles suspended in a fluid1 but it is a passage from chemical solution to non-solution1 or insolubility1 that is required4 ,if1 on the other hand1 he means to say1 that the solution actually took place more quickly1 and was more immediately followed by precipitation1 because the quantity of the menstruum was insufficient1 this is to assert1 that the weaker the cause1 the more instantaneous will be its effect4 ,of two propositions the one of which is nugatory1 and the other absurd1 it is not material to inquire which the author had in view4 ,,note ,,vii4 #af4 ,compression in the mineral regions4 #afc4 ,it is worthy of remark1 that the effects ascribed to compression in the ,huttonian ,theory1 very much resemble those which ,sir ,,isaac ,,newton supposes to be produced in the sun and the fixed stars by that same cause4 ,are not1 says he1 the sun and fixed stars great earths1 vehemently hot1 whose heat is conserved by the greatness of the bodies1 and the mutual action and reaction between them1 and the light which they emit2 and whose parts are kept from fuming away1 not only by their fixity1 but also by the vast weight and density of the atmospheres incumbent upon them1 and very strongly compressing them4#gc ,footnote #gc3 ,newton's ,optics1 ,query #aa4 #afd4 ,the fact of water boiling at a lower temperature under a less compression1 is sufficient to justify the supposition1 that bodies may be made by pressure to endure extreme heat1 without the dissipation of their parts1 that is1 without evaporation or combustion4 ,a further postulatum is introduced in ,dr ,hutton's theory1 namely1 that compound bodies1 such as carbonate of lime1 when the compression prevents their separation1 may admit of fusion1 notwithstanding that the fixed part may be infusible when separated from the volatile4 ,this assumption is supported by the analogical fact of the fusion of the carbonate of barytes1 as mentioned in the text4 #afe4 ,in a region where the action of heat was accompanied with such compression as is here supposed1 there could be no fire1 properly so called1 and no combustion2 this is admitted by ,dr ,hutton1 and it is therefore a fallacious argument which is brought against his theory1 from the impossibility of fire being maintained in the bowels of the earth4 ,this impossibility is precisely what he supposes2 and yet ,mr ,kirwan's arguments are directed1 not against the existence of heat in the interior of the earth1 but against the existence of burning and inflammation4 ,after taking notice1#gd that ,saussure had succeeded1 though with extreme difficulty1 in melting a particle of limestone1 so small as to be visible only with a microscope1 what 7adds he7 must have been the heat necessary to melt whole mountains of this matter8 ,judging by all that we at present know of heat1 such a high degree could only be produced by the purest air1 acting on an enormous quantity of combustible matter4 ,now1 ,,ehrman observed1 that the combustion of two hundred and eighty cubic inches of air1 acting on charcoal1 was not able to effect the fusion of one grain of ,carrara marble2 from whence it is apparent1 that all the air in the atmosphere1 nor in ten atmospheres1 would not melt a single mountain of this substance1 of any extent1 even if there were a sufficient quantity of inflammable matter for it to act upon4 ,judging also of subterraneous heat by what we know of that of volcanoes1 no such heat exists3 the highest they in general produce1 is that requisite for the fusion of the volcanic glass called obsidian1 which ,saussure found not to exceed #aae of ,wedgewood2 but basaltine1 which requires #adj of ,wedgewood1 is never melted in the lavas of tna4 ,how little capable1 then1 would volcanic heat be to effect the fusion of ,carrara marble1 which1 according to the same excellent author1 would require a heat of upwards of #fcjj of ,wedgewood1 if this pyrometer could extend so far8 ,and in what circumstances does ,dr ,hutton suppose this astonishing heat to have existed1 and even still to exist1 under the ocean1 in the bowels of the earth1 where neither a sufficient quantity of pure air1 nor of combustible matter1 capable of such mighty effects1 can1 with any appearance of probability1 be supposed to exist3 and1 without these1 such degrees of heat cannot even be imagined1 without flying into the region of chimeras4 ,footnote #gd3 ,geol4 ,essays1 p4 #dec4 #aff4 ,now1 this reasoning is not applicable to ,dr ,hutton's hypothesis of subterraneous heat1 because it is grounded on experiments1 where that very separation of the volatile and fixed parts takes place1 which is excluded in that hypothesis4 ,when limestone or marble is exposed to such heat as is here mentioned1 or even to heat of a degree vastly inferior1 the carbonic gas is expelled1 and the body is reduced to pure lime2 from the refractory nature of which1 as we learn from the fact relative to barytes1 mentioned above1 no conclusion can be drawn as to the infusibility of the same substance1 when combined with the carbonic gas4 ,the ,carrara marble may require a heat of #fcjj of ,wedgewood1 to melt it in the open air1 where the carbonic gas escapes from it2 but under such a pressure as would retain this gas1 it cannot be inferred1 that it might not melt with the heat of a glass-house furnace4 ,in like manner1 it may be true1 that two hundred and eighty cubic inches of air1 acting on charcoal1 cannot effect the fusion of one grain of this marble1 after its fixed air is driven off from it2 but we cannot from thence draw any inference1 applicable to a case where the carbonic gas is retained1 and where the action of heat is independent of atmospheric air4 ,nothing1 therefore1 can be more inconclusive than this reasoning1 as it proceeds on the supposition1 that ,dr ,hutton's system admits propositions1 which in fact it expressly denies4 #afg4 ,of the production and maintenance of heat1 in circumstances so different from those of ordinary experience1 we can hardly be expected to give any explanation2 but we are not entitled1 merely on that account1 to doubt of the existence of such heat4 ,mr ,kirwan thinks otherwise3 ,judging1 he says1 from all we at present know of heat1 such a high degree of it1 7as will melt limestone17 could only be produced by the purest air1 acting on an enormous quantity of combustible matter4 ,without these1 such degrees of heat cannot even be imagined1 without flying into the region of chimeras4#ge ,footnote #ge3 ,geol4 ,essays1 p4 #ded4 ,now1 in the first place1 the high degree of temperature which is here understood1 is probably not necessary to the purposes of mineralization1 as has just been shown2 and1 in the second place1 it is not ,,fire1 in the usual sense of the word1 but ,,heat1 which is required for that purpose2 and there is nothing chimerical in supposing1 that nature has the means of producing heat1 even in a very great degree1 without the assistance of fuel or of vital air4 ,friction is a source of heat1 unlimited1 for what we know1 in its extent1 and so perhaps are other operations1 both chemical and mechanical2 nor are either combustible substances1 or vital air1 concerned in the heat thus produced4 ,so also the heat of the sun's rays in the focus of a burning glass1 the most intense that is known1 is independent of the substances just mentioned2 and1 though that heat certainly could not calcine a metal1 nor even burn a piece of wood1 without oxygenous gas1 it would doubtless produce as high a temperature in the absence as in the presence of that gas4 ,it is true1 that it is not by the solar rays that subterraneous heat is produced2 but still1 from this instance1 we see1 that there is no incongruity in supposing the production of heat to be independent of combustible bodies1 and of vital air4 ,we are indeed1 in all cases1 strangers to the origin of heat2 philosophers dispute1 at this moment1 concerning the source of that which is produced by burning2 and much more are they at a loss to determine1 what upholds the light and heat of the great luminary1 which animates all nature by its influence4 ,if we would form any opinion on this object1 we shall do well to attend to the suggestions of that great philosopher1 who was hardly less from others by his doubts and conjectures1 than by his most rigorous and profound investigations4 ,may not great1 dense1 and fixed bodies1 when heated beyond a certain degree1 emit light so copiously1 as1 by the emission and reaction of its light1 and the reflections and refractions of its rays within its pores1 to grow still hotter1 till it comes to a certain period of heat1 such as is that of the sun8 ,and1 are not the sun and fixed stars great earths1 vehemently hot1 whose heat is conserved by the greatness of the bodies1 and the mutual action and reaction between them and the light which they emit8#gf ,footnote #gf3 ,newton's ,optics1 ubi supra4 #afh4 ,some recent experiments1 seem to make the suggestions in this query applicable to an opaque body like the earth1 as well as to luminous bodies1 such as the sun and fixed stars4 ,the radiation of heat1 where there is no light1 was first rendered probable by the experiments of ,m4 ,,pictet of ,geneva2#gg and the only objections to which the conclusions from those experiments seemed liable1 are removed by the late very important discoveries of ,dr ,,herschel4#gh ,from these it appears1 that heat is capable of refraction and reflection1 as well as light1 so that it is not absurd to suppose1 that the heat of great1 dense1 and faced bodies1 may be conserved by the greatness of the bodies1 and the mutual action and reaction between them and the heat which they emit4 ,footnote #gg3 ,essai sur le ,feu4 ,footnote #gh3 ,phil4 ,trans4 #ahjj1 p4 #hd4 ,the existence of subterraneous heat is still further rendered probable from the researches of ,,mairan1 which tend to show1 that there is another source of terrestrial heat besides the influence of the solar rays4#gi ,footnote #gi3 ,mm4 de l',acad4 des ,sciences1 #agfe1 p4 #adc4 ,whatever be the truth with regard to these conjectures1 it is certain1 that the first and original source of heat is independent of burning4 ,burning is an effect of the concentration of heat2 and though1 by a certain reaction1 it has the power of continuing and augmenting that heat1 it never can be regarded as its primary and material cause4 ,when1 therefore1 we suppose a source of heat1 independent of fire and of burning1 we suppose what certainly exists in nature1 though we are not informed of the manner of its existence1 nor of its place1 otherwise than from considering the phenomena of the mineral kingdom4 #afi4 ,lastly1 we are not entitled1 according to any rules of philosophical investigation1 to reject a principle1 to which we are fairly led by an induction from facts1 merely because we cannot give a satisfactory explanation of it4 ,it would be a very unsound view of physical science1 which would induce one to deny the principle of gravitation1 though he cannot explain it1 or even though the admission of it reduces him to great metaphysical difficulties4 ,if indeed a downright absurdity1 or inconsistency with known and established facts1 be involved in any principle1 it ought not to be admitted1 however it may seem calculated to explain other appearances4 ,if1 for instance1 ,dr ,hutton held1 that combustion was carried on in a region where there was no vital air1 we should have said1 that he admitted an absurdity1 and that a theory founded on such postulata was worse than chimerical4 ,but1 if the only thing imputable to him is1 that1 being led by induction to admit the fusion of mineral substances in the bowels of the earth1 he has assumed the existence of such heat as was sufficient for this fusion1 though he is unable to assign the cause of it1 ,i believe it will be found1 that his system only shares in an imperfection1 which is common to all physical theories1 and which the utmost improvement of science will never completely remove4 #agj4 ,thus1 then1 we are led1 it must be allowed1 into the region of hypothesis and conjecture1 but by no means into that of chimeras4 ,indeed1 the reproach of flying into the latter region1 may be said to come but ill from one1 who has trode so often the crude consistence of the chaos1 and who delights to dwell beyond the boundaries of nature4 ,by sojourning there long1 it is not impossible that the eye may become so accustomed to fantastic forms1 that the figures and proportions of nature shall appear to it deformed and monstrous4 ,,note ,,viii4 #bd4 ,sparry structure of calcareous petrifactions4 #aga4 ,when the shells and corals in limestone are quoted by mineralogists1 it is not always considered in what state they are found4 ,in general1 they have a sparry structure1 very different from that of the original shell or coral1 of which1 however1 they retain the figure with wonderful exactness1 though probably sometimes altered in size4 ,though sparry1 they are often foliated1 and preserve their animal1 in conjunction with their mineral1 texture4 ,now1 this crystallization is a mark of some operation1 quite different from any that can be ascribed to the water in which these bodies had their origin1 and by which they were brought into their place4 ,they were impervious to water2 and it cannot be said that their sparry structure has been derived from the percolation of that fluid1 carrying new calcareous matter into their pores4 ,we can account for the change produced in them1 ,i think1 only by supposing them to have been softened by heat1 so as to permit their parts to arrange selves anew1 and to assume the characteristic organization of mineral substances4 ,all shells have not the change effected on them that is here referred to2 those in chalk1 for instance1 retain very much their original form in all respects4 ,this is what we might expect from the very different degree of intensity1 with which the mineralizing cause has acted on chalk1 and on limestone or marble4 ,in general1 it is in the hardest and most consolidated limestone1 that the marine objects are most completely changed into spar4 ,it would be exceedingly interesting to examine1 whether any of the phosphoric acid remains united to shells of either of these kinds4 ,we might most readily expect it to be united1 in a certain degree1 to the shells that are least mineralized4 ,this experiment would enable us also to appreciate the force of ,mr ,kirwan's argument against the finer marbles1 such as the ,carrara1 containing shells4#hj ,this argument proceeds on an experiment1 mentioned in the ,turin ,memoirs for #aghi1 from which it appears1 that no phosphoric acid is found in pure limestone2 and its absence1 ,mr ,kirwan says1 cannot be attributed to fusion1 as phosphoric acid is indestructible by heat4 ,footnote #hj3 ,geol4 ,essays1 p4 #deh4 ,he calls this a demonstration2 but1 in order to entitle it to that name1 it will be necessary1 first1 to prove1 that phosphoric acid exists in those limestones which evidently consist of shells in a mineralized state4 ,if these are found without phosphoric acid1 it is evident that the preceding argument fails entirely4 ,if they are found to contain that acid1 it will then no doubt afford a probability1 though not a demonstration1 that ,carrara marble does not directly originate from shells4 ,that nature has some process1 by which the above acid is separated from the earth of bones1 and probably also from the earth of shells1 is evident from the state in which the bones are found in the caves of ,bayreuth4 ,those that are the most recent1 and least petrified1 contain most of the phosphoric acid4 ,where the petrifaction has proceeded far1 that acid is not found4 #agb4 ,among many of the strata1 such a fluidity has prevailed1 as to enable some of the substances included in them to crystallize4 ,calcareous spar and siliceous crystals are often found in stratified rocks1 forming veins of secretion1 or lining close cavities1 included on all sides by the uncrystallized rock4 ,in the instances of gneiss1 and many species of marble1 almost the whole matter of the stratum is crystallized4 ,this union of a stratified and crystallized structure in the same substance1 has a great affinity to that union of the crystallized with the organic structure of shells and corals which has just been mentioned2 and both are doubtless to be referred to the same cause4 ,,note ,,ix4 #ha4 ,petroleum1 c4 #agc4 ,according to the theory of coal laid down above1 its two chief materials1 charcoal and bitumen1 being furnished by the vegetable and animal kingdoms1 both of the land and of the sea1 have formed with one another a new combination1 by the action of subterraneous heat2 but have also1 in some cases1 been separated by that same action1 where the degree of compression necessary for their union1 happened to be wanting4 ,the carbonic part1 when thus separated from the bituminous1 forms an infusible coal1 which burns without flame3 the bituminous part1 when separated from the carbonic1 is found in the various states of naphtha1 petroleum1 asphaltes1 and jet4 ,the great resemblance of infusible or blind coal1 to the residuum obtained by the distillation of bituminous coal2 and again1 the coincidence of the bitumens just named1 with the volatile part1 or the matter brought over by such distillation1 are strong arguments in favour of this theory4 ,the other facts in the natural history of coal1 serve to confirm the same conclusion2 but it must be confessed1 that what we know of the pure bitumens1 except the circumstance just mentioned1 is of a more ambiguous nature1 and may be reconciled with different theories4 ,the drops of petroleum contained within the cavities of the limestone1 mentioned at #ca1 are however strong facts in confirmation of ,dr ,hutton's opinions1 and they are furnished by the substances purely bituminous4 ,a careful examination would probably make us acquainted with others of the same kind1 for limestone is very often the matrix in which petroleum and asphaltes are contained4 ,the greatest mine of asphaltes in ,europe1 that in the ,val de ,travers in the territory of ,neufchtel1 is in limestone1 from which1 though it in some places exudes1 it is in general extracted by the application of heat4 ,the strata for several leagues are impregnated with bitumen2 and1 if examined with attention1 would probably afford specimens similar to those which have just been mentioned4 #agd4 ,it is a general remark1 that1 where petroleum is found1 on digging deeper1 they come to asphaltes2 and1 at a depth still greater1 they discover coal4 ,this probably does not hold invariably2 but it is certain1 that most of the fountains of petroleum are in the neighbourhood of coal strata4 ,petroleum and asphaltes are found in great abundance in ,alsace1 in a bed of sand1 between two beds of clay or argillaceous schistus1 and the same country also affords coal4#ha ,this is true likewise of the fossil pitch of ,coal-,brookdale2 and of the petroleum found in ,st ,catharine's ,well1 near ,edinburgh4 ,auvergne#hb contains abundance of fossil pitch1 which exudes1 in the warm season1 from a rock impregnated with it through its whole mass4 ,there are also coal strata in the same country1 not far distant4 ,footnote #ha3 ,encyclopdia1 mot1 ,asphalte4 ,footnote #hb3 ,voyage en ,auvergne1 par ,lagrand1 tom4 i4 p4 #cea4 ,a very satisfactory observation relating to this subject1 has lately been communicated from a country1 with whose natural history we were till of late entirely unacquainted4 ,in the ,burmha empire1 petroleum is dug up in an argillaceous earth1 from the depth of seventy cubits4 ,this argillaceous earth1 or schistus1 lies under a bed of freestone2 and under all1 about one hundred and thirty cubits from the surface1 is a bed of coal4#hc ,footnote #hc3 ,asiatic ,researches1 vol4 vi1 art4 #f4 p4 #acj4 #age4 ,in the petroleum lake of the ,island of ,trinidad1 described ,phil ,trans4 #aghi1 the petroleum evidently exudes from the rock1 and is collected in a variety of springs in the bottom1 after which it hardens1 and acquires the consistency of pitch4 ,the manner1 therefore1 in which petroleum exists in the strata1 is very consistent with the idea of its having been introduced in the form of a hot vapour4 ,even amber appears to have some relation to coal4 ,it is found in the unconsolidated earth in ,prussia and ,pomerania2 but ,i am not sure whether this earth is travelled or not4 ,in the same earth where the amber is found1 there is often a mixture of coaly matter1 which burns in the fire2 it is apparently fibrous1 and has been considered as a kind of fossil-wood4#hd ,footnote #hd3 ,buffon1 ,hist4 ,nat4 des ,mineraux1 tom4 ii4 p4 #e4 ,these circumstances make out a connection between the purer bitumens and ordinary coal2 but do not1 it must be acknowledged1 establish any thing with respect to the more immediate relation1 supposed in this theory to exist between them and blind coal4 ,it is probable1 indeed1 that1 to discover any facts of that kind1 the natural history of both substances must be more carefully examined2 the natural history of blind coal1 in particular1 has hitherto been but little attended to4 #agf4 ,a fact is mentioned by ,mr ,kirwan1 which must not be regarded as less valuable for being adverse to this theory4 ,it is1 that neither petroleum1 nor any fossil bitumen1 is found in the vicinity of the ,kilkenny coal1 as might be expected1 if that coal was deprived of its bituminous part by subterraneous distillation4#he ,this1 however1 admits of explanation4 ,though a general connection1 on the above hypothesis1 might be expected between bitumens and infusible coal1 we cannot look for it in every instance4 ,the heat which drove off the bitumen from one part of a stratum of coal1 may only have forced it to a colder part of the same stratum2 and thus1 in separating it from one portion of carbonic matter1 may have united it to another4 ,blind coal may therefore be found where no bitumen has been actually extricated4 ,in like manner1 bitumen may have been separated1 where the coal was not reduced to the state of coke1 as a part of the bitumen only may have been driven off1 and enough left to prevent the coal from becoming absolutely infusible4 ,footnote #he3 ,geol4 ,essays1 p4 #dgc4 ,it should be considered too1 if the bitumen was really separated1 and forced1 in the state of vapour1 into some argillaceous or limestone stratum1 that this stratum may have been wasted and worn away long ago1 so that the bitumen it contained may have entirely disappeared4 ,it does not therefore necessarily follow1 that1 wherever we find blind coal1 there also we should discover some of the purer bitumens4 ,,note ,x4 #cg4 ,the height above the level of the sea at which the marks of aqueous deposition are now found4 #agg4 ,we have two methods of determining the minimum of the change which has happened to the relative level of the sea and land2 or for fixing a limit1 which the true quantity of that change must necessarily exceed4 ,the one is1 by observing to what height the regular stratification of mountains reaches above the present level of the sea2 the other is1 by determining the greatest height above that level1 at which the remains of marine animals are now found4 ,of these two criteria1 the first seems preferable1 as the fact on which it proceeds is most general1 and least subject to be affected by accidental causes1 or such as have operated since the formation of the rocks4 ,the results of both1 however1 if we are careful to select the extreme cases1 agree more nearly than could have been expected4 #agh4 ,the mountain ,rosa1 in the ,alps1 is entirely of stratified rocks1 very regularly disposed1 and nearly horizontal4#hf ,the highest summit of this mountain is1 by ,saussure's measurement1 #bdcj toises1 or #adgci ,english feet1 above the level of the sea1 or lower than the top of ,mont ,blanc only by #bj toises1 or #abh feet4#hg ,this is1 ,i believe1 the highest point on the earth's surface1 at which the marks of regular stratification are certainly known to exist2 for though1 by the account of the same excellent mineralogist1 ,mont ,blanc itself is stratified1 yet1 as the rock is granite1 the stratification vertical1 and somewhat ambiguous1 it is much less proper than ,monte ,rosa for ascertaining the limit in question4 ,footnote #hf3 ,voyages aux ,alpes1 tom4 iv4 #bach4 ,footnote #hg3 ,ibid4 #bace4 #agi4 ,again1 in the new continent1 we have an instance of shells contained in a rock1 not much lower than the summit of ,monte ,rosa4 ,this is one described by ,don ,,ulloa1 near the quicksilver mine of ,guanca-,velica1 in ,peru4 ,the height at which a specimen of these shells1 given by ,ulloa to ,m4 ,le ,,gentil1 was found1 was #bbbb #a_/c toises1 or #adaij feet ,english1 above the level of the seas4#hh ,this height agrees with the preceding1 within #edi feet1 a quantity comparatively small4 ,footnote #hh3 ,see ,hist4 ,acad4 des ,sciences1 #aggj4 ,phys4 ,gnrale1 ,no4 #g4 #ahj4 ,the last of the facts just mentioned is curiously commented on by ,mr ,kirwan4 ,as he has proved1 he says1 that the mountains higher than #hejj feet were all formed before the creation of fish1 it follows1 that the shells found at ,guanca-,velica1 must have been carried there by the deluge4#hi ,now1 without objecting to the proof here referred to1 7though it seems very open to objection17 it is sufficient to remark1 that1 if the shells at ,guanca-,velica were carried there by the deluge1 or any other cause that operated after the formation of the rock of which the mountain consists1 they can make no part of that rock1 but must lie1 like other adventitious fossils1 loose and detached on the surface1 or at most externally agglutinated to the stone4 ,this1 however1 is certainly not the fact2 for1 in the account just quoted1 we read1 that ,don ,ulloa told ,m4 le ,gentil1 qu'il avoit dtach ces coquilles d'un banc fort pais4 ,this seems plainly to indicate1 that the shells were included in a bed of rock2 ,but1 granting that the expression is a little ambiguous1 on turning to the ,mmoires ,philosophiques of the same author1 the difficulty is completely removed1 and it is made evident1 that these shells are in fact integrant parts of the rock4 ,on voit dans ces montagnes-l1 7about ,guanca-,velica1 and particularly at that in which is the quicksilver mine17 des coquilles entires1 petrifies et enfermes au milieu de la roche1 que les eaux de pluie mettent decouvert4 ,ces coquilles font corps avec la pierre2 mais malgr cela1 on remarque que la partie qui fut coquille1 se distingue par la couleur1 la structure1 la qualit de la matire de tout autre corps pierreux qui l'enferme1 et du massif qui s'est fix entre les deux ecailles1#ij c4 ,he goes on to say1 that one can distinguish marks of these shells having been worn1 before they were included in the stone4 ,footnote #hi3 ,geol4 ,essays1 p4 #ed4 ,footnote #ij3 ,mm4 ,philosophiques de ,don ,ulloa1 ,discours xvi4 vol4 i4 p4 #cfd4 #aha4 ,thus it appears1 that whatever proof any fossil shell affords1 that the rock in which it is found was formed under the sea1 the same is afforded by the fossil shells of ,guanca-,velica2 and we are1 therefore1 perfectly entitled to conclude1 that the relative level of the sea and land has changed1 since the formation of the latter1 by more than #adjjj feet4 ,the height assumed in #cg is therefore much under the truth2 and the water1 for which the ,neptunists must provide room in subterraneous caverns1 might very well have been stated at more than a five-hundredth part of the whole mass of the earth4 ,thus also the argument by which the ,neptunists would connect the creation of fish with the beginning of the secondary mountains1 falls entirely to the ground4 ,indeed1 it is strange that ,mr ,kirwan should have supposed it possible1 that the shells in question were loose and unconnected with the rock1 and had continued so1 ever since the deluge1 in such elevated ground1 where the torrents wear and cut down the mountains with unexampled violence1 and have hollowed out ,quebradas so much deeper and more abrupt than the glens or vallies among other mountains4 ,he had not1 ,i believe1 seen the passage ,i have quoted from ,ulloa2 but the circumstances did not warrant the shells in question to be regarded as extraneous and adventitious fossils4 ,a geologist should have known better than to suppose this possible4 ,when we see ,,voltaire ascribing to accidental causes the transportation of those shells which he had been told were often found among the ,alps1 we can excuse in a ,poet and a ,wit1 that ignorance of the facts in mineralogy1 which concealed from him the extreme absurdity of his assertion2 but when a ,chemist or ,mineralogist talks and reasons in the same manner1 we cannot consider him as entitled to the same indulgence4 ,,note ,,xi4 #db4 ,fracture and dislocation of the strata4 #ahb4 ,the greatest part of the facts relative to the fracture and dislocation of the strata1 belongs to the history of veins4 ,the instances of slips1 where no new mineral substance is introduced between the separated rocks1 are what properly belong to this place4 ,the frequency of these1 and their great extent1 are well known wherever mines have been wrought4 ,in some of them no opening is left1 but the slipped strata remain contiguous2 in other cases1 there is introduced an unconsolidated earth1 often a clay1 which may be supposed to have come from above1 arid very probably to have been carried down by the water4 ,in some such cases1 however1 there are not wanting appearances1 which show the matter in the slip to have been forced up from below1 as we find it to contain substances which could not have come from the surface4#ia ,footnote #ia3 ,unconsolidated earth contained between the sides of a rock that has slipped1 is frequent in ,cornwall1 and is called a ,fleukan4 #ahc4 ,a very remarkable fact of this kind occurred not long ago1 in digging the ,huddersfield canal in ,yorkshire2 and a very distinct account of it is given in the ,philosophical ,transactions1 by the engineer who directed the work4 ,in carrying a tunnel into the heart of a hill1 the miners came to what is called in the description a fault1 throw1 or break1 or what we have here called a shift1 which was filled with shale set on edge1 mixed with softer earth1 and in some places with small lumps of coal4 ,the fault or space filled with these materials1 was in general about four yards broad1 and lay nearly in the direction of the tunnel1 so that a considerable extent of it was visible4 ,beside the shale1 it contained a rib of limestone1 about four feet thick1 which run parallel to the sides of the fault1 and about four feet from the southern margin of it4 ,on each side of this rib were found balls of limestone1 promiscuously scattered1 and of various sizes1 from an ounce to one hundred pounds weight4 ,the balls1 when broken1 were found to contain some pyrites near their edges2 they were not perfectly globular1 but flattened on the opposite sides1 and similar to one another4#ib ,at the time when the account was written1 about seventy yards of the rib had been discovered4 ,footnote #ib3 ,phil4 ,trans4 #agif1 p4 #cej4 #ahd4 ,now1 it is certain1 that neither this rib of limestone1 nor the balls that accompanied it1 can have come from above1 as there is no limestone within twenty miles of the place where they were found4 ,they must1 therefore1 have been forced up from below1 and no doubt belong to some limestone strata1 which lie there at a great depth under the surface4 ,the length of this fragment of rock1 which1 from the account1 one must suppose to have been entire1 conveys no mean idea1 either of the intensity or regularity of the force by which it was brought into its present situation4 ,in veins1 it is not uncommon to meet with stones that appear to have come from a greater depth3 but this is probably the most remarkable instance of the same phenomenon1 which has appeared in a mere slip1 and none1 ,i think1 can speak a language less liable to be misunderstood4 #ahe4 ,i shall here mention another mark of violent fracture1 that has been observed in rocks of breccia or pudding-stone1 which1 though not of the same kind with the preceding1 and of a nature quite peculiar1 belongs rather to this place than any other4 ,in rocks of the kind1 just mentioned1 it sometimes happens1 that considerable portions are separated from one another1 as if by a mathematical plane1 which had cut right across all the quartzy pebbles in its way4 ,none of the pebbles are drawn out of their sockets1 that is1 out of the cement that surrounds them1 but are divided in two with a very smooth and even fracture4 ,the pebbles1 in the instances which ,i have seen1 were of quartz1 and other species of primary and much indurated rock4 ,lord ,,webb ,,seymour and ,i observed pudding-stone rocks1 exhibiting1 instances of this singular kind of fracture1 near ,oban1 in ,argyleshire1 about three years ago4 ,the phenomenon was then entirely new to us both2 but ,i have since met with an instance of the same kind in ,saussure's last work4 ,as the fact is of so particular a kind1 ,i shall state it in his own words3 ,the place was on the sea shore1 near the little town of ,alassio1 between ,nice and ,genoa4 ,en passant entre ces blocs de breche1 j'admirai quelques-uns d'entr'eux1 d'une grandeur considrable1 et taills en cubes1 avec la plus parfaite rgularit4 ,il y avoit ceci de remarquable1 c'est que l'action de la pesanteur1 qui avoit taill ces cubes en rompant leurs couches1 avoit coup tous les cailloux des breches fleur de la surface de la pierre1 aussi nettement que si c'et t une masse molle qu'on et tranche verticalement avec un rasoir4 ,cependant parmi ces cailloux1 la plupart calcaires1 il s'en trouvoit de trs durs1 de petrosilex1 par exemple1 mme de jade1 qui toient tranches tout aussi nettement que les autres4#ic ,footnote #ic3 ,voyages aux ,alpes1 tom4 iii4 #agca4 #ahf4 ,this description is no doubt accurate1 though it involves in it something of theory1 viz4 that the fracture was made by the weight of the stone4 ,this may indeed be true3 the operation probably belongs altogether to the surface1 and is one with which the powers of the mineral regions are not directly concerned4 ,the phenomenon1 however1 appears to me1 on every supposition1 very difficult to explain4 ,in the specimen which ,i brought from ,oban1 the smallest pieces of stone are cut in two1 as well as the largest4 ,the consolidation and hardness of the mass are very great1 and the connection of the different fragments so perfect1 that it is no wonder the whole should break as one stone4 ,but still1 that the fracture should be so exactly in one plane1 and without any shattering1 is not a little enigmatical2 if it is indeed a fracture1 it must be the consequence of an immense impulse1 very suddenly communicated4 ,,note ,,xii4 #dc4 ,elevation and inflection of the strata4 #ahg4 ,the evidence of the different formation of the primary and secondary strata1 and of the changes which the former have undergone1 is best seen at the points where those strata come into contact with one another4 ,dr ,hutton was not the first who observed these junctions1 though the first who rightly interpreted the appearances which they exhibit4 ,he has mentioned observations of this sort by ,de ,luc on the confines of the ,hartz2 by the author of the ,tableau de la ,suisse1 at the pass of ,yetz2 by ,voight1 in ,thuringia2 and ,schreiber1 at the mountain of ,gardette4#id ,footnote #id3 ,theory of the ,earth1 vol4 i4 p4 #daj to #dec4 ,the leading facts to be remarked1 are1 ,i4 ,the vertical or very upright position of the primary or lower strata4 ,,ii4 ,the superstratification of the secondary1 in a position nearly horizontal1 so as to be at right angles to those on which they rest4 ,,iii4 ,the interposition of a breccia between them or1 as happens in many cases1 the transition of the lowest of the secondary beds into a breccia1 containing fragments sometimes worn1 sometimes angular1 of the primary rock4 ,this last is a phenomenon extremely general1 and all our subsequent information confirms ,dr ,hutton's anticipations concerning it4 ,it will be very remarkable1 he says1 if similar appearances1 7such as those of the breccia described by ,voight17 are always found upon the junction of the ,alpine with the level countries4#ie ,saussure1 in a part of his work1 not published when ,dr ,hutton wrote this passage1 has attested the generality of the fact with respect to the whole ,alps1 from the ,tyrol to the ,mediterranean3 ,un sait que l'on observe sans aucune exception1 ce sont les amas de dbris1 sous la forme de blocs1 de breches1 de poudingues1 de grs1 de sable1 ou amoncels1 et formant des montagnes1 ou des collines1 disperss sur le bord exterieur1 ou mme dans les plaines qui bordent la chaine des ,alpes4#if ,footnote #ie3 ,theory of the ,earth1 vol4 i4 p4 #ddh4 ,footnote #if3 ,voyages aux ,alpes1 tom4 iv4 #bccj4 ,this passage is perfectly decisive as to the generality of the fact1 that the ,alps1 from the ,tyrol to the ,mediterranean1 are bordered all round by pudding-stones or breccias4 ,at the same time1 it is necessary to remark1 that ,m4 ,saussure1 by enumerating loose blocks and sand1 along with pudding-stones1 breccias and grit1 confounds together things which are extremely different1 and which have had their origin at periods extremely remote from one another4 ,the consolidated rocks of breccia1 pudding-stone and grit1 though they are indications of waste1 have received their present character at the bottom of the sea3 the loose blocks of stone1 the sand and gravel1 on the other hand1 are the effects of the waste now going forward on the surface of the land1 and are the materials out of which rocks of the three kinds just mentioned may hereafter be composed4 ,if so skilful a mineralogist as ,saussure is guilty of such inaccuracy1 it must be ascribed to the confusion necessarily arising from the system which he followed1 and not to his own want of discrimination4 #ahh4 ,the same phenomenon1 of a breccia circumscribing the primary mountains1 is met with in ,scotland2 and the ,grampians1 wherever they are bounded by secondary strata1 whether on the south or north1 afford examples of it4 ,the breccia generally consists of the fragments of the primary rock1 most commonly rounded1 but sometimes also angular1 united by a cement of secondary formation1 and the whole disposed in horizontal beds4 ,it was on the constancy of this accompaniment of the primary strata1 and on the great quantity of highly polished gravel often included in these breccias1 that ,dr ,hutton grounded the hypothesis of the double raising up and letting down of the ancient strata4 ,see #dc4 #ahi4 ,as the spots where the primary and secondary rocks may be seen in contact with one another are of great importance in geology1 and present to the senses the most striking monuments of the high antiquity and great revolutions of the globe1 it may be useful to point out such of them as have been observed in this island4 ,to those which ,dr ,hutton has described1 ,i have a few more to add1 the result of some geological excursions1 which ,i made in company with the ,right ,honourable ,lord ,,webb ,,seymour1 to whose assistance ,i have been much indebted in the prosecution of these inquiries4 #aij4 ,the most southern junction which we observed is at ,torbay1 where the ancient schistus which prevails along the coast1 from the ,land's ,end to that point1 receives a covering of red horizontal sandstone1 the same which composes the greater part of ,devonshire4 ,the spot where the immediate contact is visible1 is on the shore1 a little to the south of ,paynton2 and one circumstance1 which among many others serves to distinguish the different formation of the two kinds of rock1 is1 that the schistus1 which is elevated here at an angle of about #de1 is full of quartz veins1 which veins are entirely confined to it1 and do not1 in as far as we could observe1 penetrate into the sandstone1 in a single instance4 ,it is probable1 that on the north shore of the bay1 the same line of junction is visible3 we saw it at ,babicomb ,bay1 still more to the northward4 #aia4 ,from this place1 the secondary strata of different kinds prevail without interruption1 along the coast of the ,british ,channel1 and of the ,german ,ocean1 as far as ,berwick upon ,tweed1 and for some miles beyond it4 ,the sea coast then intersects a primary ridge1 the ,lammermuir ,hills1 which traverses ,scotland from east to west1 uniting1 near the centre of the country1 with the metalliferous range of ,leadhills1 and afterwards with the mountains of ,galloway4 ,the section which the sea coast makes of the eastern extremity of this ridge1 is highly instructive1 from the great disturbance of the primary strata1 and the variety of their inflections4 ,the junction of these strata with the secondary1 on the south side1 is near the little sea-port of ,eyemouth1 but the immediate contact is not visible4 ,on the north side of the ridge1 the junction is at a point called the ,siccar1 not far from ,dunglass1 the seat of ,sir ,james ,hall1 ,baronet4 ,by being well laid open1 and dissected by the working of the sea1 the rock here displays the relation between the two orders of strata to great advantage4 ,dr ,hutton himself has described this junction2 ,theory of the ,earth1 vol4 i4 p4 #dfd4 #aib4 ,from the point just mentioned1 the secondary strata continue as far as ,stonehaven1 where the southern chain of the ,grampian mountains is intersected by the sea-coast4 ,here a great mass of pudding-stone appears to lie on the primary strata1 but their immediate contact has not been observed4 #aic4 ,going along the coast toward the north1 the next junctions which we saw were on the shore1 one near ,gardenston1 and another near ,cullen1 in ,banffshire4 ,the latter is very distinct2 it is about a mile to the westward of the rocks called ,the ,three ,kings1 where a red sandstone1 the lower beds of which involve much quartzy gravel1 lies horizontally upon very regular1 upright1 and highly indurated strata4 ,some of these strata are micaceous1 and others of the granulated quartz1 mentioned in #aec4 #aid4 ,this last is1 ,i believe1 the most northern junction which has been observed in our island4 ,the western coast furnishes several more1 which however are not all visible4 ,the line of separation1 between the primary schistus of the ,grampians and the sandstone which covers it1 is intersected at its western extremity by the ,frith of ,clyde1 not far from ,ardencaple in ,dunbartonshire4 ,the two kinds of stone can be traced within a few yards of each other1 but not to the actual contact3 the beds of sandstone nearest the schistus form as usual a breccia1 loaded with fragments of the primary rock4 ,the secondary rock1 which begins here1 continues for about fifty miles south1 to ,girvan in ,ayrshire1 where the primary schistus again rises up1 but is not seen in contact with the secondary4 ,it extends to the ,mull of ,galloway and the shores of the ,solway ,frith4 ,the ,isle of ,arran1 however1 not far distant from this part of the coast1 contains a junction at its northern extremity1 where secondary strata of limestone lie immediately on a primary micaceous schistus4 ,this is described by ,dr ,hutton1 and was the first phenomenon of the kind which he had an opportunity of examining4#ig ,the junction is visible but at one spot1 and is not seen so distinctly as in some of the instances just mentioned2 but the great quantity of pudding-stone near it1 renders it more interesting than it would be otherwise4 ,as the greater part of this little island is surrounded by secondary strata1 other junctions might be expected to be visible4 ,footnote #ig3 ,theory of the ,earth1 vol4 i4 p4 #dbi4 #aie4 ,on the coast of ,england and ,wales1 from the ,solway ,frith to the ,land's ,end1 though there are several alternations from secondary to primary strata1 ,i know not that any of them have been observed4 ,at ,st ,bride's ,bay1 in ,pembrokeshire1 the primary and secondary strata are seen very near their junction2 but the precise line ,i believe is not visible4 ,the coal-pits in the secondary strata1 approach here within a few hundred yards of the primary4 ,the secondary strata which commence at this place1 occupy both sides of the ,bristol ,channel1 and meet the ,cornish schistus1 which extends across the north of ,devonshire to the ,quantock ,hills1 in a line that may be looked for on the sea coast1 some where between ,watchett and ,minehead4 #aif4 ,besides the sea coast1 the beds of rivers may be expected to afford information on this subject4 ,to the instances ,i have mentioned1 ,i have accordingly two others from the inland country to be added4 ,one of them is from the river ,jed1 a little way above ,jedburgh1 where the secondary strata are seen lying horizontally on the primary1 a section of both being made by the bed of the river4 ,the phenomena here are very distinct1 and strongly marked2 ,dr ,hutton has described and represented them in a plate4#ih ,he has mentioned another junction1 not far from this1 which he saw in the ,tiviot4 ,both these belong to the same primary ridge with the ,siccar point4 ,footnote #ih3 ,theory of the ,earth1 vol4 i4 p4 #dcj2 also plate #c4 #aig4 ,i shall mention only one other1 which was discovered by ,lord ,webb ,seymour and myself1 at the foot of the high mountain of ,ingleborough1 in ,yorkshire4 ,as we went along the ,askrig road from ,ingleton1 about a mile and a half from the latter1 an opening appeared in the side of the hill1 on the right1 about one hundred yards from the road1 formed by a large stone1 which lay horizontally1 and was supported by two others1 standing upright4 ,on going up to the spot1 we found it was the mouth of a small cave1 the stone lying horizontally1 being part of a limestone bed1 and the two upright stones1 vertical plates of a primary argillaceous schistus4 ,the limestone bed1 which formed the roof of the cave1 was nearly horizontal1 declining to the south-east2 the schistus nearly vertical1 stretching from north-west by west1 to south-east by east4 ,the schistus1 though close in contact with the limestone1 seemed to contain nothing calcareous1 and did not effervesce with acids in the slightest degree4 ,as this cave is at the foot of ,ingleborough1 a cold wind1 #bd below the temperature of the external air1 which issued from the mouth of it1 might very well be supposed to come from the inmost recesses of that mountain4 ,ingleborough1 which consists entirely of strata of limestone and grit1 nearly horizontal1 and alternating with one another1 rises to the height of #ahjj or #bjjj feet above the spot where we now stood4 ,this1 ,i believe1 is the greatest thickness of secondary strata that has ever been observed incumbent on the primary1 and it is therefore a geological fact highly deserving of attention4 ,the country all round1 to a very great extent1 is composed of limestone1 with a few beds of grit interposed1 and forming1 beside ,ingleborough1 some other high mountains1 such as ,wharnside and ,pennigant1 all resting1 it is probable1 on the same foundation4 ,at the spot just described1 no breccia appeared to be interposed between the primitive and secondary rock2 but we found a breccia at another point of the same junction1 not far distant4 ,this was at a cascade1 in the river ,greta1 called ,thornton ,force1 about two miles and a half from the place just mentioned4 ,the ,greta here precipitates itself from a horizontal rock of limestone2 and1 after a fall of about eighteen or twenty feet1 is received into a bason which it has worked out in the primary schistus4 ,this schistus is in beds almost perpendicular2 it exactly resembles that which has ,just been described1 and stretches nearly in the same direction4 ,on the south side of the river a breccia was seen1 lying upon the schistus1 or rather1 it might be said1 that the lowest beds of limestone contained in them many rounded fragments of stone1 which1 on comparison1 resembled exactly the schistus underneath4 ,the primary rock itself is here seven or eight hundred feet above the level of the sea4 ,the same schistus1 somewhat lower down the valley1 and nearer to ,ingleton1 appears in large quantities1 and is quarried for slate4 ,here1 however1 the immediate junction of the limestone and schistus does not appear4 ,i have dwelt longer on the description of these appearances than on any others of the same kind1 because1 from the great mass of secondary strata which here covers the primary1 the circumstances are such as we cannot expect to see very often exemplified4 #aih4 ,the ,lakes of ,cumberland are much visited by travellers2 and it may be worth remarking1 on that account1 that1 as the site of these lakes is a patch of primary country1 bounded on all sides by secondary1 so1 in the rivers that run from the lakes1 such junctions as we are now treating of may be expected to be found4 ,under ,dun-,mallet1 on the side toward ,ulles ,water1 we observed a breccia1 which was in horizontal layers1 and seemed to lie on the primary schistus1 so that the whole hill is perhaps a piece of more indurated breccia1 or secondary rock1 which has resisted the wearing and washing down of the rivers better than the rest4 #aii4 ,after ascertaining the fact of the disturbance of the strata1 and their removal from their original position1 it is of consequence to inquire into the direction of the force by which these changes have been produced4 ,now1 if the disturbed or elevated strata1 were every where in planes1 without bending or sinuosity1 it might perhaps be hard to determine1 whether that force had acted in the direction of gravity1 or in the opposite4 ,either supposition would account for the appearances2 and1 as gravity is a known force1 providing we can find some place fit to receive the matter impelled downward by it1 its action would furnish the most probable solution of the difficulty4 ,it is on this principle that the ,neptunian system proceeds1 imagining1 that certain great caverns or vacuities having been opened in the interior of the globe1 a great part of the waters which formerly covered its surface1 retired into them1 and much of the solid rock also sunk down at the same time4 ,in this way1 one extremity of a stratum has been elevated1 while the other has been depressed1 and a certain inclination to the horizon has been given to the whole of it4 ,thus one cause serves two purposes2 the vacuities in the interior of the earth account1 both for the depression of the sea1 and the elevation of the land2 and the ,neptunists1 if the phenomena were all such as have been now stated1 might boast of a felicity of explanation1 not very usual in their system4 ,but this appearance of success vanishes1 when the elevation and disturbance of the strata are more minutely examined1 and are found to include waving and inflection1 in a great variety of forms4 ,it then becomes evident1 that the beds of rock1 at the time when they were disturbed from their horizontal position1 had not their present hardness and rigidity1 but were1 in a certain degree at least1 soft and flexible4 ,without these qualities1 they could not have received1 as they have often done1 the curvature of a circle1 not many feet1 nay1 not many inches1 in diameter2 nor could they have been bent into superficies1 with their curvature in opposite directions1 so that the same surface is in one part convex1 and in another concave1 on the same side1 with a line of contrary flexure interposed4 ,these are appearances1 not reconcilable with the mere falling in1 and breaking down of indurated rocks4 #bjj4 ,the inflections and wavings that we are here speaking of1 though not peculiar to the primary strata1 are found most frequently among them1 and are perfectly familiar to every one who his travelled among mountains with any view to the study of geology4 ,the following are a few instances of this phenomenon out of a great number which might be produced4 ,saussure1 in describing the route from ,geneva to ,chamouni1 mentions many remarkable instances of the bending of the strata1 and particularly where the small stream of ,nant d',arpenaz forms a cascade1 by falling over the face of a perpendicular limestone rock4 ,the strata of this rock are bent into circular arches1 extremely regular1 and with their concavity turned to the left4 ,what deserves particularly to be remarked1 is1 that a mountain behind the cascade has its strata bent in a direction opposite to the former1 or with their concavity to the right4 ,there is no doubt that the strata of both rocks are the same1 so that a vertical section of them would give a curve1 in the figure of an ,s4#ii ,these circumstances are mentioned by ,saussure1 and from them we may infer this other property of these strata1 that their section by a horizontal plane1 must exhibit a system of straight lines1 probably all parallel to one another4 ,footnote #ii3 ,voyages aux ,alpes1 vol i4 #dgb2 also1 ,theory of the ,earth1 vol4 ii4 p4 #cj4 ,the same mineralogist describes the calcareous strata which compose the mountain ,axenberg1 on the side of the ,lake of ,lucerne1 as having from top to bottom of the mountain the form of the letter ,s compressed1 7ecrase7 with their curvature in some places very great4 ,these inflections are repeated several times1 and often in contrary directions2 the layers are sometimes broken1 where their curvature is greatest4#ajj ,footnote #ajj3 ,voyages aux ,alpes1 tom4 iv4 #aice4 ,on the side of the same lake1 is another instance of bent strata1 in a mountain1 of which the beds are horizontal in the lower part1 but are bent at one end upwards1 in the form of the letter ,c4 ,the horizontal part is of great extent1 and the rock is also calcareous1#aja ,footnote #aja3 ,ibid4 #ccg4 ,the ,montagne de la ,tuile1 near ,montmelian1 receives its name from the beds of rock being incurvated in form of a tyle4#ajb ,among secondary mountains1 the same kind of phenomena are observed1 though less frequently1 and with less variety of inflection4 ,the chain of ,jura is secondary1 and the beds which compose it are of limestone1 or of grit3 they are bent in such a manner1 that in a transverse section of the mountain1 each layer would have the figure of a parabola4#ajc ,footnote #ajb3 ,ibid4 vol4 iii4 #aahb1 and plate i4 ,footnote #ajc3 ,ibid4 tom4 i4 #ccd4 #bja4 ,the ,pyrenees furnish abundance of phenomena of the same kind1 as we learn from the ,essai sur la ,mineralogie des ,pyrenes4 ,the calcareous strata of the valley of ,aspe1 represented plate v4 of that work1 deserve particularly to be remarked4 #bjb4 ,our own island abounds with examples of the bending and inflection of the strata1 especially the primary1 and many of them very much resembling those in the ,alps and ,pyrenees4 ,on the top of the mountain of ,ben-,lawers1 in ,perthshire1 there is a rock1 the face of which exhibits a section of a great number of thin equidistant layers1 bent backwards and forwards like those described by ,saussure2 and this unequivocal proof of the rock having once existed in the state of a flexible and tenacious paste1 is rendered more striking1 by the great elevation of the spot1 and the ruggedness and induration1 both of the stone itself1 and of every thing that surrounds it4 ,many other mountains in this tract consist of a schistus1 which is talcose rather than micaceous1 and subject1 in a remarkable degree1 to the sort of sinuosity and inflection here treated of4 ,the appearances of the primary strata on the coast of ,berwickshire1 have been already mentioned1 as affording much valuable instruction in geology4 ,they also exemplify the waving and inflection of the strata on a large scale1 and with great variety4 ,a section of some of them is given by ,dr ,hutton1 in his ,theory of the ,earth1 vol4 i4 from a drawing made by ,sir ,james ,hall4 ,the nature of the curve superficies into which the schistus is bent1 is the better understood from this1 that1 besides transverse sections from north to south1 the deep indentures which the sea has made1 and the projecting points of rock1 exhibit many longitudinal sections1 in a direction from east to west4 #bjc4 ,the dock-yards at ,plymouth are in several places cut out of a solid rock of primary schistus1 singularly incurvated4 ,the inflections are seen there to great advantage1 being exhibited in three sections1 at right angles to one another1 transverse1 longitudinal and horizontal4 #bjd4 ,from these instances1 to which it were easy to add many more1 two conclusions may be drawn4 ,the first of these is very obvious1 viz4 that the strata must have been pliant and soft when they acquired their present form4 ,the bending of an indurated bed of stone into an arch of great curvature1 and without fracture1 as in the preceding examples1 is a physical impossibility4 ,saussure has indeed observed a fracture to accompany the bending1 in one or two cases2 but it is an uncommon phenomenon1 and1 where it happens1 must no doubt be understood to indicate an imperfect flexibility4 ,now1 if it be granted that the strata were at any time soft and flexible1 since their complete formation1 it will be found impossible to deny their having been softened by the application of heat4 #bje4 ,the second conclusion1 alluded to above1 results from a property1 which belongs very generally1 if not universally1 to the inflections of the strata4 ,this consists in their curvature being simple1 or in one dimension only1 like a cylindric superficies1 not double1 or in two dimensions1 like the superficies of a sphere or spheroid4 ,this may be otherwise expressed by saying1 that the sections of the bent strata1 by a horizontal plane1 are straight lines1 parallel to one another4 ,on this account1 every such stratum seems as if it were bent over all axis and the axes of all these different bendings1 for a great extent of country1 are nearly parallel4 ,the truth of this is evident1 where the strata are seen both transversely and longitudinally4 ,it holds remarkably of the primary schistus on the coast of ,berwickshire2 where the beds of rock1 if cut transversely1 by a vertical plane1 exhibit the figures of very complicated curves1 with various maxima and minima1 and points of contrary flexure2 but1 if they are cut by a horizontal plane1 the section will produce nothing but straight lines1 nearly parallel4 #bjf4 ,the constancy of the direction of the primary strata1 when estimated by their intersection with the horizontal plane1 is often very remarkable4 ,their elevation and flexure are subject to great and sudden changes1 so as to pass not only from greater to less1 but from one side to the opposite1 within a small distance2 but the horizontal line in which they stretch1 usually preserves the same bearing to a great extent4 ,the general direction of the primary strata1 in the south part of ,scotland1 is from ,e4,n4,e4 to ,w4,s4,w42 and the same is nearly true of those which compose the ridge of the ,grampians on the north1 and the hills of ,cumberland and ,westmoreland toward the south1 though between the schistus of these three tracts1 there is no communication at the surface1 each being entirely separated from the one next it1 by the interposition of secondary strata4 ,i have already mentioned the observations of ,lord ,webb ,seymour and myself1 at the foot of ,ingleborough2 and it appears from them1 that the vertical schistus on which that mountain rests1 though it still preserves an eastern and western direction1 varies several points from that of the more northern strata4 ,the strata of ,wales return more to the first mentioned direction1 and those of ,devonshire and ,cornwall agree with it very nearly4 ,in all this1 it will be easily conceived1 that ,i do not mean to speak with absolute precision1 or to deny the existence of great local irregularities4 ,the result given is only a kind of average1 deduced from observations hardly susceptible of great exactness1 and not yet sufficiently multiplied to give to the conclusion all the accuracy it may attain4 #bjg4 ,this tendency of the primary strata to take a uniform direction1 has also been observed in other countries4 ,saussure remarked in the ,alps1 that the beds of schistus are generally parallel to the chains of mountains composed of them2#ajd and this remark is probably applicable to all mountains consisting of primary strata4 ,the general direction1 therefore1 of the schistus of the ,alps1 must be confined between ,w4 #aj ,s4 and ,w4 #dj ,s4 ,in the ,pyrenees1 the direction of the strata is about ,w4,n4,w4#aje ,if ,saussure's rule may be depended on1 the schistus of the ,altaic1 and most of the other great chains in the old continent1 are in directions that run considerably to the south of west4 ,the ,urals1 and perhaps some other of the northern chains1 are however entirely different4 ,in the ,urals1 as we learn not only from the general direction of the chain1 but from a section of it in the #ajth volume of the ,nova ,acta of ,petersburgh 7,tab4 #ab17 the direction of the strata is nearly from ,n4 to ,s4 ,this last is probably the direction in the great chains of ,south ,america2 so that the uniformity of direction in the primary strata1 which some mineralogists would extend to those of the whole earth1 is certainly imaginary1 though there can be no doubt that it extends over very large portions of the earth's surface4#ajf ,footnote #ajd3 ,voyage aux ,alpes1 tom4 i4 #egg4 ,footnote #aje3 ,essai sur la ,mineralogie des ,pyrenes4 ,footnote #ajf3 ,it is perhaps unnecessary to observe1 that the two propositions1 that the intersections of the strata with the horizon are parallel lines2 and that they are lines which reserve the same bearing with respect to the points of the compass2 are nearly the same thing for tracts of moderate extent1 but for large portions of the earth's surface are extremely different4 ,if1 for instance1 the belt of primary vertical schistus1 which traverses the south of ,scotland1 were to be produced eastward in the same plane1 from its northern extremity1 where its direction is ,e4,n4,e4 and its latitude #ee #eg'1 it would cut the meridian always less obliquely as it advanced1 till1 having increased it longitude about #bf #bh'1 it would be at right angles to the meridian1 and its direction of consequence due east and west4 ,this would happen in the parallel of #eh #ea'1 7on the shore of the ,gulf of ,finland1 near ,revel17 the strata being now extended about #hhj ,g4 miles from the ,siccar ,point4 ,conversely1 vertical strata1 having the same bearing with respect to the meridian1 may be in planes very much inclined to one another4 ,a stratum which bears east and west in ,cornwall1 and one that does the same at the east end of the ,altaic1 will be in planes1 which1 if produced1 would cut one another at right angles4 ,all this is sufficiently plain from the doctrine of the sphere1 and is mentioned here merely as a caution to prevent too hasty conclusions from being drawn from any correspondence of bearing among the strata of remote countries4 ,for the sake of those who would deduce the medium bearing of any body of strata from a number of observations1 it may be proper to take notice1 that the true average is not to be found by simply taking an arithimetical mean among all the observations4 ,a more exact way is to work by the traverse table1 as in keeping a ship's reckoning1 7supposing the distance run to be always unity17 and to compute from the observed bearings the amount of all the southing or northing1 and also all the easting and westing4 ,the sum of all the latter1 divided by the sum of all the former1 is the tangent of the angle which the general direction of the strata makes with the meridian4 #bjh4 ,the tendency of the primary strata to remain straight in the horizontal direction1 and to be bent in the vertical1 is a phenomenon which points very directly to the causes from whence it has arisen4 ,a surface of simple curvature1 or a surface straight in one direction1 is what the application of forces to different points of a plane1 which is flexible1 though with a certain degree of rigidity1 will naturally produce4 ,the supposition1 therefore1 that these strata were once flat and horizontal1 and were impelled upward from that situation before they had become rigid or hard1 will explain their having the kind of curvature which removes them as little as possible from their original condition4 ,but no other hypothesis affords any reason why they should have that curvature more than any other4 ,from the falling in of roofs of caverns1 we might expect fracture and dislocation1 without any order or regularity2 but certainly no bending or sinuosity1 nor any symmetrical arrangement4 ,if1 as some mineralogists allege1 the curvature1 as well as inclination of the strata1 arose from the irregularities of the bottom on which they were deposited1 why is the former in one dimension only1 and why is it not in every direction1 like that of hills and valleys1 or the actual surface of the earth8 ,or1 lastly1 if the whole structure of the primitive mountains is an effect of crystallization1 and if these mountains are now such as they have ever been from the time of their consolidation1 whence is it1 that1 in their bendings the law just mentioned is so constantly observed8 ,indeed1 the idea of ascribing the inflections of the strata to crystallization1 though suggested by ,saussure1#ajg and since become a favourite system with several mineralogists1 appears to me in the highest degree unsatisfactory and illusive4 ,the purpose for which crystallization is here introduced1 is not to give a specific figure to a particular substance1 but to arrange the substances which it has formed and figured1 according to certain rules2 a work which we know not how it is to perform1 and in which we have no experience of its power4 ,accordingly1 this principle does not account1 in any way whatever1 for the circumstances which attend the inflection of the strata1 for the simple curvature which they affect1 nor for that parallelism of their layers1 which1 in all their bendings1 is so accurately preserved4 ,it does1 indeed1 so little serve to explain these facts1 that1 were the appearances completely reversed2 did the strata assume the most complex1 instead of the most simple curvature2 instead of equidistant1 were they converging1 or alternately receding and approaching to one another2 the theory of crystallization might be equally applied to them4 ,the state of the phenomena is a matter of perfect indifference to such a theory as this2 all things are explained by it with the same facility2 the straight and the crooked1 the square and the round1 the moveable and the immoveable4 ,is it not evident that such an explanation is a mere word2 or1 if any thing more than a word1 an expression of our ignorance1 so awkward and indirect1 as to deprive us of whatever credit might have been gained by a plain and candid avowal of it8 ,footnote #ajg3 ,voyages aux ,alpes1 tom4 i4 #dge4 ,it should never be forgotten1 that a theory which accounts for any thing1 and a theory which accounts for nothing1 stand precisely on the same footing1 and ought to be banished from all parts of philosophy1 as they have been from those sciences which are justly honoured with the name of accurate4 ,the animated orbs of ,aristotle1 and the vortices of ,des ,cartes1 have long ceased to be mentioned in physical astronomy2 the first1 because1 they accounted for every thing alike2 the second1 because1 when they accounted for one thing1 they never could be made to account for another4 ,both theories1 therefore1 have very properly been rejected2 and1 when geology shall undergo a similar purification1 the principle we have been considering will not be the only sacrifice required of the ,neptunian system4 #bji4 ,an appearance observed in some kinds of primary schistus1 which clearly indicates their deposition by water1 and in planes very different from those in which we now see them1 though it might have been introduced before1 is also much connected with the present argument4 ,this appearance consists of small wavings or undul on the surface of the plates of schistus1 precisely similar to these marks which are left by the sea on a gently inclining beach of sand1 at the ebbing of the tide4 ,all the species of schistus do not seem to afford instances of these wavings4 ,the rocks which do so1 are1 ,i think1 chiefly of the argillaceous kind1 but often highly indurated2 so that the lamin containing the impressions are not to be torn asunder but with great difficulty4 ,instances of it abound in the schistus of ,berwickshire1 and are also not unfrequent in that of ,galloway4 ,all must agree about the agent which produced these marks2 it could be no other than the sea2 but it must have been the sea acting on loose1 small and round particles1 lying on a surface which was nearly horizontal4 #baj4 ,dr ,hutton's theory is no where stronger1 than in what relates to the elevation and inflection of the strata2 points in which all others are so egregiously defective4 ,the phenomena to be connected are here extremely various1 and even in appearance contradictory3 the horizontally of one part of the strata2 the inclined or vertical position of another2 the perfect planes in which one set are extended2 the breaking and dislocation found in a second2 the inflection and sinuosity of a third2 and almost every where the utmost rigidity and induration1 combined with appearances of the greatest softness and flexibility2 the preservation of a parallelism of superficies in the midst of so much irregularity1 and the assumption of a determinate species of curvature1 under circumstances the most dissimilar2 all these appearances were to be connected with one another1 and with the consolidation of the strata1 and this is done by the twofold hypothesis1 of aqueous deposition1 and the action of subterraneous heat4 ,when these circumstances are fairly considered1 and when the shifts which other systems are put to on this occasion are remembered1 ,i think it will be granted1 that few attempts at generalization have been more successful1 than that which has been made by the ,huttonian ,theory4 #baa4 ,to the fact of the elevation of the strata1 the study of geology is much indebted4 ,the stratified form of a great proportion of the earth's surface1 gives to minerals that organization and regularity1 which makes their disposition an object of science1 and their inclined position serves to bring that organization into view1 from far greater depths than we can ever reach by artificial excavations4 ,if1 for instance1 the termination of strata1 that make with the horizon an angle of #cj1 lying one over another1 is seen for a horizontal distance of two miles2 then it is certain1 that if these strata have that extent under ground1 which may be reasonably supposed1 the thickness of the whole mass1 measured by a line perpendicular to its stratification1 is half the horizontal distance1 or amounts to one mile4 ,it would also require a pit to be sunk from the uppermost of these strata1 to the depth of 7#b miles tan #cj1 7 #fjic feet before it could intersect the undermost2 and therefore1 if we suppose the same stratum to preserve the same character for the extent of some miles1 we obtain the same information from inspecting the edge-seams1 and see in reality as far into the bowels of the earth1 as if we had sunk a perpendicular shaft to the depth of #fjjj feet4 ,in general1 the length of the horizontal line drawn across the strata1 from the lowest in position to the highest1 multiplied into the sine of the inclination of the strata to the horizon1 gives the thickness of the whole1 measured perpendicularly to the plane of the stratification3 and the same horizontal distance1 multiplied into the tangent of the inclination1 gives the actual depth at which the lowest stratum would meet a perpendicular to the horizon1 drawn from the highest extremity of the upper stratum4 ,in many cases1 the extent of stratified materials admitting of such an examination as this1 is much greater than has now been supposed4 ,m4 ,pallas describes a range of hills on the south-east side of the peninsula of the ,tauride1 which is cut down perpendicularly toward the sea1 and offers a complete section of the parallel beds of a primary1 or1 as he calls it1 an ancient limestone1 inclined at an angle of #de to the horizon2 and this section continues for the length of #acj versts1 or about #hf ,english miles4 ,the beds are so regular1 that ,m4 ,pallas compares them to the leaves of a book4#ajh ,the height of these hills does not exceed #abjj feet1 but the real height of the uppermost stratum above the undermost1 is #hf #a_/b #hf #e_/g #fa miles nearly4 ,footnote #ajh3 ,see ,nova ,acta ,acad4 ,petropol4 tom4 x4 7#agib17 p4 #beg4 ,if therefore we conceive that there is no shift in all this great system of strata1 we in reality are enabled1 by means of it1 to see no less than #fa miles into the interior of the earth1 nearly a #feth part of the radius of the globe4 ,it is true1 that we can hardly suppose so great a body of strata to have been raised without shifting1 so that we must diminish this depth considerably2 but were it reduced even to one-half it will appear1 that men see much farther into the interior of the globe than they are aware of1 and that geologists are reproached without reason for forming theories of the earth1 when all that they can do is but to make a few scratches on its surface4 ,art indeed can do little more2 but nature supplies the deficiency1 and makes discoveries to the attentive observer1 on the same great scale with her other operations4 ,the simplest account that can be given of the vast body of parallel and highly inclined strata just mentioned1 is1 that it consists of the ends of horizontal strata1 or of strata not greatly inclined1 that have been forced up when they were all soft and flexible4 ,this is a much more conceivable supposition than ,pallas's1 viz4 that the greater part of this mass has sunk down into some vast cavern in the interior of the earth4 ,,note ,,xiii4 #ec4 ,metallic ,veins4 #bab4 ,the large specimens of native iron found in ,siberia and ,peru1 mentioned above1 #ea1 are among the most curious facts in the natural history of metals4 ,it has been doubted1 however1 by some1 whether they really belong to natural history1 or are not rather to be accounted artificial productions4 ,if they had been found in the heart of rocks1 or in the midst of metallic veins1 no doubt of this sort could possibly have been entertained2 but1 as they lie quite on the surface1 in the middle of flat countries1 and at a distance from any known vein of metal1 the conjecture that they may be artificial1 and the remains of the iron founderies of ancient and unknown nations1 is at first sight not entirely destitute of probability4 ,this probability1 however1 will appear to be the less1 the more carefully the specimens are examined4 ,the metal is too perfect1 and the masses too large1 to have been melted in the furnaces1 or to have been transported by the machinery1 of a rude people4 ,the specimen in ,south ,america weighs #cjj quintals1 or about #ae tons1 and is soft and malleable4#aji ,the ,siberian specimen1 described by ,pallas1 is also very large2 it is soft and malleable1 and full of round cavities1 containing a substance1 which1 on examination1 has been found to be chrysolite4#aaj ,now1 it is certainly quite impossible1 that1 in an artificial fusion1 so much chrysolite could have come by any means to be involved in the iron2 but1 if the fusion was natural1 and happened in a mineral vein1 the iron and the chrysolite were both in their native place1 and their meeting together has nothing in it that is inexplicable4 ,footnote #aji3 ,phil4 ,trans4 #aghh1 p4 #cg4 also p4 #ahc1 c4 ,footnote #aaj3 ,kirwan's ,mineralogy1 vol4 ii4 art4 ,native ,iron4 #bac4 ,some circumstances in the description of the specimen in ,south ,america1 such as the impressions of the feet of men and of birds on its surface1 are not to be accounted for on any hypothesis1 and certainly require more careful investigation4 ,it is said1 that this iron is very little subject to rust1 and the analysis of a piece of it by ,,proust makes it probable1 that it owes this quality to its union with nickel4#aaa ,it appears1 also1 that the country of ,chaco1 where this specimen was found1 affords many others of the same kind1 one of which is mentioned in the description above referred to4 ,that country lies on the east side of the ,plata1 and is a plain extremely level1 and of vast extent1 without any appearance of mineral veins2 but such veins may nevertheless exist undiscovered1 in a tract subject to periodical inundations1 and where the native rock is covered with alluvial earth and gravel to a great depth4 ,the veins maybe washed away1 and the more durable substances1 such as those pieces of native iron1 may be left behind2 and1 though they must be of a formation extremely ancient1 according to this hypothesis1 they may not have been very long on the surface4 ,footnote #aaa3 ,annales de ,chimie1 tom4 xxxv4 ,messidor1 p4 #dg4 #bad4 ,specimens of native iron have been found1 less remarkable than the preceding for their size1 but in circumstances that excluded all idea of artificial fusion4 ,of this sort was ,,margraaf',s specimen of native iron1 the first of the kind that was known2 it consisted of small bits of soft and malleable iron1 found in the heart of a brown iron-stone4#aab ,this makes it certain1 that native iron is a natural production1 and the mere circumstance of great magnitude1 in the specimens before mentioned1 does not entitle us to doubt of their having that same origin4 ,it is a circumstance1 besides1 not in the least material to this argument2 the smallest piece of native iron being as much a proof of fusion as the greatest2 and the specimen of ,margraaf being just as conclusive in favour of the ,huttonian ,theory1 as those of ,pallas or ,de ,celis1 supposing their reality in mineral productions to be completely established4 metal malleable and ductile1 in ever so small a quantity1 cannot be the result of precipitation from a menstruum1 without a very particular combination of circumstances4 ,such a metal1 can the other hand1 can be readily produced by igneous fusion2 so that here the negative and affirmative parts of the inductive argument may both be regarded as complete4 ,footnote #aab3 ,kirwan's ,mineralogy1 vol4 ii4 p4 #aef4 #bae4 ,mr ,kirwan1 in order to account for the magnitude of the two large specimens mentioned above1 supposes1 that small pieces of native iron 7about the formation of which he appears to have no difficulty7 have been originally agglutinated by petroleum1 and left bare1 when the surrounding stony or earthy masses either withered or were washed off4#aac ,this is no doubt the most singular of all the opinions which have been advanced on the subject2 and1 as it borrows nothing from analogy1 it admits of no proof1 and requires no refutation4 ,none but a chemist of eminence could have ventured with impunity on an assertion so inconsistent with all the phenomena and principles of his science4 ,footnote #aac3 ,geol4 ,essays1 p4 #dje4 #baf4 ,a remark of the same author1 on the subject of the native gold found in the county of ,wicklow in ,ireland1 is entitled to more attention4 ,that these lumps of native gold1 he says1 were never in fusion1 is evident from their low specific gravity1 and the grains of sand found in the midst of them4 ,i found the specific gravity of a lump of the size of a nutmeg to be only #abhjj1 whereas1 after fusion1 it became #ahgjj4aad ,footnote #aad3 ,ibid4 p4 #djb4 ,this argument is plausible2 but1 ,i think1 nevertheless inconclusive4 ,the sand found in the gold1 accounts1 at least in part1 for its lightness4 ,it is only by repeated fusions that any of the metals is brought to its utmost purity and highest specific gravity2 and on no supposition can the melting of gold in the mineral regions1 be very likely to separate it from heterogeneous substances4 ,that quartzy sand should be found in it1 after such a process1 is naturally to be expected4 ,the impressions which the quartz crystals have left on the ,wicklow gold1 would be received as a full proof of the fusion of that metal1 if geologists always regulated their theories by the principles which determine the belief of ordinary men4 #bag4 ,don ,rubin de ,celis1 in the paper referred to above1 mentions some masses of silver found at ,quantajaia1 and also some dust of platina1 in terms that excite a strong desire to have more information concerning them4 ,they are considered by him as effects of volcanic fire2 so we may conclude1 that they contain evident marks of fusion1 and would in this system be ascribed to that heat1 from which volcanic fire is but a partial and accidental derivation4 #bah4 ,the state also in which gold and silver are often found pervading masses of quartz1 and shooting across them in every direction1 furnishes a strong argument for the igneous origin1 both of the metal and the stone4 ,from such specimens1 it is evident1 that the quartz and the metal crystallized1 or passed from a fluid to a solid state1 at the same time2 and it is hardly less clear1 that this fluidity did not proceed from solution in any menstruum3 ,for the menstruum1 whether water or the chaotic fluid1 to enable it to dissolve the quartz1 must have had an alkaline impregnation2 and1 to enable it to dissolve the metal1 it must have had1 at the same time1 an acid impregnation4 ,but these two opposite qualities could not reside in the same subject2 the add and alkali would unite together1 and1 if equally powerful1 form a neutral salt1 7like sea-salt17 incapable of acting either on the metallic or the siliceous body4 ,if the acid was most powerful1 the compound salt might act on the metal1 but not at all upon the quartz2 and if the alkali was most powerful1 the compound might act on the quartz1 but not at all on the metal4 ,in no case1 therefore1 could it act on both at the same time4 ,fire or heat1 if sufficiently intense1 is not subject to this difficulty1 as it could exercise its force with equal effect on both bodies4 #bai4 ,the simultaneous consolidation of the quartz and the metal is indeed so highly improbable1 that the ,neptunists rather suppose1 that the ramifications in such specimens as are here alluded to1 have been produced by the metal defusing itself through rifts already formed in the stone4#aae ,but it may be answered1 that between the channels in which the metal pervades the quartz1 and the ordinary cracks or fissures in stones1 there is no resemblance whatever3 ,that a system of hollow tubes1 winding through a stone1 7as the tubes in question1 must have been1 according to this hypothesis1 before they were filled by the metal17 is itself far more inconceivable than the thing which it is intended to explain2 and lastly1 that if the stone was perforated by such tubes1 it would still be infinite to one that they did not all exactly join1 or inosculate with one another4 ,footnote #aae3 ,geol4 ,essays1 p4 #dja4 #bbj4 ,the compenetration1 as it may be called1 of two heterogeneous substances1 has here furnished a proof of their having been melted by fire4 ,the inclusion of one heterogeneous substance within another1 as happens among the spars and drusens1 found so commonly in mineral veins1 often leads to a similar conclusion4 ,thus1 from a specimen of chalcedony1 including in it a piece of calcareous spar1 ,dr ,hutton has derived a very ingenious and satisfactory proof1 that these two substances were perfectly soft at the same time1 and mutually affected each other at the moment of their concretion4#aaf ,footnote #aaf3 ,theory of the ,earth1 vol4 i4 p4 #ic4 ,each of these substances has its peculiar form1 which1 when left to itself1 it naturally assumes2 the spar taking the form of rhombic crystals1 and the chalcedony affecting a mammalated structure1 or a superficies composed of spherical segments1 contiguous to one another4 ,now1 in the specimen under consideration1 the spar is included in the chalcedony1 and the peculiar figure of each is impressed on the other2 the angles and planes of the spar are indented into the chalcedony1 and the spherical segments of the chalcedony are imprinted on the planes of the spar4 ,these appearances are consistent with no notion of consolidation that does not involve in it the simultaneous concretion of the whole mass2 and such concretion cannot arise from precipitation from a solvent1 but only from the congelation of a melted body4 ,this argument1 it must be remarked1 is not grounded on a solitary specimen1 7though if it were it might still be perfectly conclusive17 but on a phenomenon of which there are innumerable instances4 #bba4 ,according to this theory1 veins were filled by the injection of fluid matter from below2 and this account of them1 which agrees so well with the phenomena already described1 is confirmed by this1 that nothing of the substances which fill the veins is to be found any where at the surface4 ,it is not with the veins as with the strata1 where1 in the loose sand on the shore1 and in the shells and corals accumulated at the bottom of the sea1 we perceive the same materials of which these strata are composed4 ,the same does not equally hold of metallic veins3 ,look1 says ,dr ,huston1 into the sources of our mineral treasures8 ,ask the miner from whence has come the metal in his veins8 ,not from the earth or air above1 not from the strata which the vein traverses3 these do not contain an atom of the minerals now considered4 ,there is but one place from whence these minerals may have come2 this is the bowels of the earth2 the place of power and expansion2 the place from whence has proceeded that intense heat1 by which loose materials have been consolidated into rocks1 as well as that enormous force1 by which the regular strata have been broken and displaced4#aag ,footnote #aag3 ,theory of the ,earth1 vol4 i4 p4 #acj4 #bbb4 ,the above is a very just and natural reflection2 but if1 instead of interrogating the miner2 we consult the ,neptunist1 we will receive a very different reply4 ,as this philosopher never embarrasses himself about preserving a uniformity in the course of nature1 he will tell us1 that though it may be true1 that neither the air1 the upper part of the earth's surface1 nor even the sea1 contain at present any thing like the materials of the veins1 yet the time was when these materials were all mingled together in the chaotic mass1 and constituted one vast fluid1 encompassing the earth2 from which fluid it was1 that the minerals were precipitated and deposited in the clefts and fissures of the strata4 #bbc4 ,it is alleged1 in proof of this hypothesis1 that mineral veins are found to be less rich as they go farther down1 whereas they ought to be richer if they were filled by the projection of melted matter from below4 ,but the fact1 that mines are less rich as they descend farther1 though it may hold in some instances1 is not general1 and may therefore be supposed to arise from local causes1 such as are1 in respect of us1 accidental1 and beyond the limits to which our theories can be expected to reach4 ,thus the mines of ,mexico and ,peru are said to be subject to the preceding rule2 but in the mines of ,derbyshire and ,cornwall1 the very contrary is understood to take place4 ,besides1 what we are pleased to call the riches of a mine1 are riches relatively to us1 and relatively to a distinction which nature does not recognise4 ,the spars and veinstones which are thrown out in the rubbish of our mines1 may be as precious in the eyes of nature1 as conducive to the great objects of her economy1 and are certainly as characteristic of mineral veins1 as the ores of silver or gold1 to which we attach so great a value4 ,unless the former are in smaller quantity1 or less highly crystallized at great than at small depths1 which ,i believe is not alleged1 no conclusion can be drawn from substances1 which occupy in general but a small proportion of any vein1 and1 in their dissemination through it1 do not seem to be always guided by the same law4 #bbd4 ,again1 if the veins were filled by deposition from above1 we ought to discover in them such horizontal stratification as is the effect of deposition from water1 and we should perceive no marks of the materials having been introduced with violence into their place4 ,the ,neptunists cannot object to the trial of their theory by these two frets4 ,as to the first1 it is acknowledged1 that there is a certain regular disposition of the substances in mineral veins1 as stated #ei1 but it is one which has hardly any thing in common with the real phenomena of stratification4 ,it consists in the distribution of the principal substances in coats parallel to the sides of the vein1 each substance forming a separate coat4 ,in a vein1 for instance1 containing quartz1 fluor1 calcareous spar1 lead1 c4 we might expect to find a lining of quartz crystals1 applied immediately to the walls of the mine1 and following exactly the irregularities of their surface2 next1 perhaps1 a coat of fluor1 then of calcareous spar1 and last of lead ore in the centre of the vein1 the same order being observed on the opposite side4 ,these successive coats1 it is material to remark1 are not in planes1 but in uneven surfaces1 of which the inequalities are evidently determined by those of the walls1 that is1 of the rock which forms the sides of the vein2 neither are they horizontal1 but are parallel to the walls1 whether these be perpendicular or inclined4 ,here1 therefore1 there is no appearance of the action of that statical law which has directed the arrangement of the other strata1 and which tends to make the plane of every stratum deposited by water perpendicular to the direction of gravity4 ,the coating of the veins has therefore been performed under the conduct of some other power than that which presides over aqueous deposition4 ,if1 as the ,neptunists maintain1 the materials in the veins were deposited by water1 in the most perfect tranquillity1 it is wonderful that we do not find those materials disposed in horizontal layers1 across the vein1 instead of being parallel to its sides2 and it seems very unaccountable1 that the common strata1 deposited as we are told while the water was in a state of great agitation1 have so rigorously obeyed the laws of hydrostatics1 7 #ch47 and acquired a parallelism in the planes of their stratification1 which approaches so often to geometrical precision2 while the materials of the veins1 in circumstances so much more favourable for doing the same1 have done nearly the reverse1 and taken a position1 often at right angles to that which hydrostatical principles require4 ,this is a paradox which the ,neptunian system has created1 and which therefore it is not very likely to resolve4 #bbe4 ,mere words should have little power to mislead1 in a science which treats of sensible objects1 such as are always easily subjected to the examination of sight or of touch2 yet there is some appearance as if the ,neptunists were misled in this1 and other instances1 by the term stratification4 ,though an incrustation on the perpendicular face of a rock has very little affinity to a stratum1 such as we are accustomed to see deposited by water1 yet the same name being once imposed on both1 mineralogists have proceeded to reason concerning them1 as if they were precisely the same thing1 and were both to be ascribed to the same cause4 ,indeed every perpendicular or highly inclined bed of stone1 is inexplicable as an effect of aqueous deposition1 in a system1 unprovided1 as the ,neptunian is1#aah with the means of raising up such beds from a horizontal into a vertical position4 ,this observation may also be extended to all cases of vertical stratification4 ,water cannot directly arrange its deposits in planes highly inclined1 and therefore ,i have often wondered to see the ,neptunists contending so eagerly for the stratification of certain rocks1 such as granite1 which1 being vertical1 or highly inclined1 was much less friendly to their system than the entire absence of all stratification would have been4 ,i was disposed to admire their candour1 when the use which they made of the fact convinced me1 that ,i ought only to wonder at their inconsequential reasoning4 ,the ,huttonian ,theory is1 indeed1 the only one which possesses the means of reconciling the elevation of the strata with their horizontal deposition1 and which is entitled to consider stratification1 in whatever plane it may be1 as originally the work of the ocean4 ,the geologists who attach themselves exclusively to the action of water1 will never be able to extend the dominion of that element so far as ,dr ,hutton has done1 by combining it with fire4 ,footnote #aah3 ,see preceding note4 #bbf4 ,but1 though the ,neptunian system were provided with engines1 powerful enough to raise up strata from a level to a vertical plane1 this would avail nothing in the present instance2 since1 on no supposition1 can the incrustations on the perpendicular sides of a vein have ever been horizontal4 ,on no supposition1 therefore1 can these incrustations be received as a proof of aqueous deposition3 it may indeed be certainly inferred from them1 that the matter which they consist of was fluid at the time of their formation2 but the absence of all appearance of a horizontal disposition1 in any part of the vein1 amounts nearly to a demonstration1 that this fluidity did not proceed from solution in a menstruum4 ,we must therefore conceive the coats to have been formed during the refrigeration of the melted matter injected from the mineral regions into the clefts and fissures of the strata4 7 #ei47 #bbg4 ,mineral veins1 particularly at their intersections with one another1 contain abundant marks of the most violent and repeated disturbance 7 #ef474 ,not to mention that they owe their first formation to the fracture and displacing of rocks already consolidated1 it appears1 that they have originated at very different periods1 and that the birth of each has been accompanied with convulsions1 which shook the foundations of the earth4 ,in ,cornwall1 for instance1 the principal veins1 and those which they distinguish particularly by the name of ,lodes1 have nearly the same direction with the strata or vertical schistus1 extending from about ,e4 ,n4 ,e4 to ,w4 ,s4 ,w4 ,these1 however1 are often intersected nearly at right angles by other mineral veins1 called ,cross ,courses1 and this hardly ever happens without the latter moving1 or1 as it is called1 heaving the former out of their direction4 ,this plainly indicates1 that the cross courses are of later origin than the others1 and that their formation was accompanied with such a force1 as must1 in many substances1 have moved the whole body of rock which constitutes the promontory of ,cornwall1 and probably much more1 for several yards1 in a horizontal direction4 ,sometimes1 also1 both the longitudinal and the cross vein are forced out of their place by a third4 ,these disturbances arise not only from mineral veins1 but from veins of porphyry and granite1 the production of which has been attended with no less violence than of the others4 #bbh4 ,what is here said of ,cornwall1 is the history1 in some degree1 of all mineral countries whatever4 ,the great horizontal translation which has thus accompanied the formation of veins2 the movement impressed on such vast bodies of rock1 and the frequent renewal of these immense convulsions2 are not to be explained by the mild and tranquil dominion of the watery element4 ,they require the utmost power that is known any where to exist1 and were it not for the admonitions of the volcano and the earthquake1 we might doubt if even subterraneous heat itself possessed an energy adequate to these astonishing effects4 #bbi4 ,from the heaving of one vein by another1 it is evident1 that there was a force of protrusion in the direction of one of them1 that acted at the time of its formation4 ,this force cannot be accounted for on the supposition that veins were produced by the mere shrinking of the strata2 for the rocks could not1 in that case1 have been rent asunder1 and impelled forward at the same time4 ,it appears most likely1 that fissures in the strata were made1 at least in many instances1 and the matter poured into them1 nearly at the same time1 both being effects of the same cause1 the expansive force of subterraneous heat4 #bcj4 ,it is remarked1 at #ef1 that the shifting of the strata is best observed where the veins make a transverse section of beds of rock1 considerably inclined to the horizon4 ,it is also true1 that in some cases the near approach of the strata to the level1 may make the shifts produced by the veins very easy to be discovered4 ,thus in ,derbyshire1 where the mineral veins are in secondary strata1 nearly horizontal1 there is almost no instance in which the corresponding strata are not observed to be on different levels1 on the opposite sides of the same vein4 #bca4 ,the fact described by ,de ,luc1 and referred to at #ee1 may1 for what we know of it1 admit of being explained in two ways4 ,the great wedge of rock which appears to be insulated between two branches of the same vein1 may either be a mass that has been broken off1 and sustained by the melted matter that flowed all around it2 or1 it may be a mass of rock contained between two veins that are in reality distinct1 and of different formation4 ,whether this last supposition is the truth1 would probably be evident from a careful examination of both parts of the vein2 as some difference of character cannot fail to be the consequence of different formation4 ,if no such difference is observed1 the two branches must be supposed to belong to the same vein1 and the only probable explanation of the insulation of so large a mass of rock will be by the first mentioned supposition4 ,this fact1 therefore1 notwithstanding the great attention ,m4 ,de ,luc has bestowed on it1 still requires further examination1 before it can be decided whether it inclines to the ,huttonian ,theory1 as on the first supposition1 or is1 as on the latter hypothesis1 equally balanced between it and the ,wernerian4 #bcb4 ,whatever be the case with this fact1 the general one of pieces of rock being found insulated in veins1 is certainly favourable to the notion of an injected and ponderous fluid having originally sustained them4 ,where1 as happens in some instances1 the stones contained in the veins have no affinity to any of the rocks above1 they cannot be supposed to have come any how but from below1 and to have been carried up by the matter of the vein4 ,the instance from the slip at the ,huddersfield ,canal has been already mentioned4 #bcc4 ,the preceding observations have been principally directed against that theory of veins which supposes them to have been filled by deposition from water4 ,there is another theory maintained by some of the ,neptunists1 that the metals in veins were introduced there by infiltration4#aai ,this opinion is sufficiently refuted by the fact1 that rarely any metallic ore is found out of the vein1 or in the rock on either side of it1 and least of all where the vein is richest4 ,this is inconsistent with the notion of the ore being carried into the vein by water percolating through the adjacent rocks1 unless some satisfactory reason is assigned1 which determined the water to leave the ore in the vein and no where else4 ,besides1 this hypothesis does not account for the formation of the spars and veinstones which fill the vein1 and which appear clearly to have been brought there at the same time with the ore1 and no doubt by the same cause4 ,footnote #aai3 ,geol4 ,essays1 p4 #dja4 #bcd4 ,the veins1 properly so called1 are indefinitely extended2 but there are also thin plates of spar1 and of crystals of different kinds1 often found included in rocks1 and shut in on all sides1 to which the name of veins is commonly applied4 ,these last ought certainly to be distinguished from the former1 and may not improperly be called ,plate ,veins or ,lenticular ,veins1 the plate or cake of spar of which they consist having very often the form of a lens1 though1 as may be supposed1 considerably irregular4 ,either of these terms being derived entirely from external characters1 has the advantage of involving nothing theoretical4 ,the lenticular veins are certainly not formed like the usual mineral veins1 by injection1 since they are shut in1 on all sides1 by the solid rock4 ,when they are found1 therefore1 in stratified rocks1 such as have not themselves been melted1 we must conceive them to be composed of materials more fusible than the surrounding rock1 so that they have been brought into fusion by a degree of heat which the rest of the rock was able to resist1 and1 on cooling1 have assumed a sparry structure4 ,when they are found in rocks1 of which the whole has been fluid1 they must be considered as component parts of that mass1 which1 by an elective attraction1 have united with one another1 and separated themselves from the substances to which they had less affinity4 ,the veins of this kind seem to be connected with those called in ,derbyshire ,pipe ,veins1 in which the ores of metals are sometimes found4 ,the pipe veins1 indeed1 are not in all cases completely insulated1 but sometimes communicate with the veins properly called mineral4 ,i am too little acquainted1 however1 with their natural history1 to ,be able to say with certainty to which of the two species they ought to be referred4 ,,note ,,xiv4 #ge4 ,on ,whinstone4 #bce4 ,to the facts and reasonings given above1 ,i shall1 in this note1 add a few remarks1 tending to show1 that whinstone is not of volcanic1 nor of aqueous1 but certainly of igneous origin4 ,it is asserted1 7 #fb17 that carbonate of lime and zeolite are often contained in whinstone1 but never in lava1 and that this circumstance may sometimes serve to distinguish these stones from one another4 ,with respect to carbonate of lime1 in particular1 it seems evident1 that this substance cannot enter into the original composition of any lava1 because the same heat which melted the lava1 would1 where there was no greater pressure than the weight of the atmosphere1 expel the carbonic acid and produce quicklime4 ,notwithstanding this1 rocks containing carbonate of lime1 have often been considered as lavas1 into the pores and cavities of which1 calcareous matter having been carried by the infiltration of water1 had crystallized into spar4 ,thus ,,spallanzani1 in his account of the ,euganean ,hills1 in ,lombardy1 describes some of the rocks as abounding at their surface1 and even in their interior1 with air-bubbles of various sizes1 from such as are hardly perceptible1 to some that are half an inch in diameter2 and which1 he says1 are all of an oval figure1 with their longest diameters in the same direction4 ,this he considers as a proof that the rock is a genuine lava2 for the air-bubbles prove the stone to have had its fluidity from fire2 and by their elongation in the same direction they prove1 that the mass when fluid was also in motion4 ,spallanzani adds1 that many of these cavities are filled with crystals of the carbonate of lime1 an effect of the infiltration of water4#abj ,footnote #abj3 ,voyages dans les deux ,siciles1 tom4 iii4 p4 #aeg4 ,edit4 de ,faujas de ,st ,fond4 #bcf4 ,though the argument here advanced for the igneous origin of the rock may be admitted as conclusive1 the introduction of calcareous spar into it by infiltration must still be questioned4 ,lava1 except in a state of decay or decomposition1 is not readily penetrated by water2 and1 if it were1 the filling of cavities with spar1 by means of the water percolating through them1 would still be subject to many difficulties1 7#ab474 ,besides1 whinstone rocks are frequently found so full of calcareous spar1 or of zeolite1 that they would become porous to such a degree1 if the cavities filled with these latter substances were all empty1 that they could hardly sustain their own weight1 and much less that of the great masses of rock incumbent on them4 ,in such cases1 it is certain1 that the crystallized substances were part of the original composition of the rock4 ,the truth is1 that the infiltration of the water is a mere gratuitous assumption1 introduced for the purpose of explaining the existence of carbonated lime in a stone which had endured the action of intense heat3 and this assumption ought of course to be rejected1 if the phenomenon can be explained by a theory1 that is in other respects conformable to nature4 ,the spar1 then1 may be considered as a proof1 that the rocks in question are to be numbered with those unerupted lavas which have flowed deep in the bowels of the earth1 and under a great compressing force4 ,this is the more probable1 that the ,euganean ,hills1 like some whinstone hills in our own country1 have1 in certain places1 a covering of slaty and calcareous strata incumbent on them1 even at their summits1#aba so that the torrent of melted stone1 of which they are admitted to consist1 cannot have flowed from the mouth of a volcano4 ,i do not mean to say1 that there are among these hills no vestiges of volcanic explosion4 ,i am very far from having data sufficient for drawing this conclusion2 but ,i believe it may be safely affirmed1 that the bulk of them is no more composed of volcanic lava1 than the basaltes of ,staffa1 or of the ,giant's ,causeway4 ,footnote #aba3 ,phil4 ,trans4 #agge1 p4 #cd4 #bcg4 ,but1 besides the evidence deduced from calcareous spar and zeolite1 against the rocks containing them being real lava1 there are other marks1 even less equivocal perhaps1 that distinguish the lavas which we suppose to have flowed in the mineral regions1 from those which have actually flowed on the surface4 ,these are what we collect from the disposition1 the organization1 or1 as we may say1 the physical geography of whinstone countries1 unlike1 in so many respects1 to that of volcanic countries4 ,the shape of whinstone hills2 their large flat terraces1 rising one above another2 their perpendicular faces1 and the correspondence of their heights even at considerable distances2 have nothing similar to them in the irregular torrents of volcanic lavas4 ,the phenomena of the former are also on a scale of magnitude very far exceeding the latter1 and clearly indicate1 that though both have been produced by fire1 it has been by fire in very different circumstances1 and regulated by very different laws4 ,the structure of the two kinds of rock agrees1 in many respects1 and so does their chemical analysis2 but their disposition and arrangement are so dissimilar1 that they cannot be supposed to be of the same formation4 #bch4 ,this argument1 ,i believe1 was first stated by ,mr ,strange1 in a letter to ,sir ,,john ,,pringle1 published in the #feth volume of the ,philosophical ,transactions4#abb ,that intelligent observer1 after visiting the countries in ,europe most remarkable either for burning1 or for what are accounted1 extinguished volcanoes1 and examining them with a very discriminating eye1 remained convinced1 that there are two distinct species of rock1 which both owe their origin to fire2 but to fire acting in circumstances and situations extremely different4 ,the first is the common volcanic lava2 the other1 to which he gives the name of a basaltine rock1 comprehends such rocks as the ,giant's ,causeway1 the basaltes of the ,vivarais1 of the ,euganean ,hills1 c4 and differs in nothing from that which is called here by the name of whinstone4 ,mr ,strange conceived1 that the one of these kinds of stone could1 no more than the other1 be accounted the work of aqueous deposition1 but was led to the distinction just mentioned1 by observing the organization and arrangement in the rocks of the latter kind1 and comparing them with the disorder and ruin that every where mark the footsteps of volcanic fire ,he does not pretend to determine the nature of the fire to which the basaltine rocks owe their formation1 nor the circumstances in which it has acted3 he is satisfied with the negative conclusion1 that it is not volcanic2 and his paper affords a specimen of what is perhaps rare in any of the sciences1 and certainly most rare of all in geology1 viz4 a philosophic induction carried just as far as the facts will bear it out1 and not a single step beyond that point4 ,footnote #abb3 ,account of ,two ,giants' ,causeways in the ,venetian ,state1 c4 by ,john ,strange1 ,esq4 ,phil4 ,trans4 vol4 lxv4 7#agge17 p4 #e1 c4 #bci4 ,several other hints contained in this paper are highly deserving of notice2 for we not only find in it the notion of a formation of basaltic rocks1 igneous though not volcanic1 but also that of their simultaneous crystallization1#abc together with the suggestion1 that granite and basalt are of the same origin1#abd ,these opinions had not1 ,i believe1 occurred at that time to any mineralogist except ,dr ,hutton1 nor had they been communicated by him to any but a few of his most intimate friends2 so that ,mr ,strange has without doubt all the merit of a first discoverer4 ,indeed1 without the knowledge of the principle of compression1 such as it is laid down by ,dr ,hutton1 it was hardly possible for him to proceed further than he has done4 ,he remarked the unburnt limestone that lies on the tops of some of the ,euganean basaltes1 and seems to have been aware of the great difficulty1 which it was reserved for the ,huttonian ,theory to overcome4 ,his letter contains also some excellent general remarks on the rocks of the ,vivarais and ,velay1 which he had visited1 before ,,faujas ,,de ,,st ,,fond had published his curious and elaborate description of these countries4 ,footnote #abc3 ,phil4 ,trans1 ubi supra1 p4 #ag4 ,footnote #abd3 ,ibid4 p4 #cf and #cg4 #bdj4 ,the cause of the peculiar structure which has just been observed to distinguish whinstone from volcanic countries1 is easily assigned in the ,huttonian ,theory4 ,according to that theory1 the whinstone rocks were formed1 in the bowels of the earth1 of melted matter poured into the rents and openings of the strata4 ,they were cast1 therefore1 in those openings1 as in a mould2 and received the impression and character of the rocks by which they were surrounded4 ,hence the tabular masses of whinstone1 which when soft have been interposed between strata1 and compressed by their weight1 so as almost to have themselves acquired the appearance of stratification4 ,hence the perpendicular faces of the same rocks1 produced by their being abutted when yet soft1 against the abrupt sides of the strata4 ,the rocks which formed those moulds have1 in many cases1 entirely disappeared2 in others1 a part still remains1 surrounding1 or even covering1 the basaltes1 as in the ,euganean ,hills1 in those of the ,val di ,noto in ,sicily1 the rocks near ,lisbon1#abe and in different parts of ,great ,britain4 ,footnote #abe3 ,recherches sur les ,volcans ,eteints du ,vivarais2 ,lettre du ,dolomieu1 p4 #ddc4 ,above all1 the veins of whinstone which intersect the strata1 are the completest proofs of the theory here given of these rocks1 and the most inconsistent1 in all respects1 with the hypothesis of their volcanic origin4 #bda4 ,if these criteria are applied to what are called extinguished volcanoes1 ,i have no doubt that many which have been reckoned of that number1 will be found to derive their origin more directly from the fire of the mineral regions4 ,the basaltic rocks of the ,vivarais1 ,i am well persuaded1 belong to this class2 and ,i conclude that they do so1 not only from the account of them given by ,mr ,strange1 but from the description of ,faujas himself1 who1 though under the influence of the opposite theory1 seems very fair and accurate in his description of phenomena4 ,the most unequivocal mark of real whinstone rock1 and of a formation in the strictest sense mineral1 is where veins of that kind of rock intersect the strata4 ,now1 in a letter to ,buffon1 on the streams of lava found in the interior of certain calcareous rocks in the lower ,vivarais1 ,faujas describes what can be accounted nothing else but a vein or dike of whinstone1 accompanied with several of its most remarkable and characteristic appearances3 ,figurez-vous un courant de lave1 de la nature du basalte noir1 dur et compacte1 qui a perc travers les masses calcaires1 et s'est fait jour dans quelques parties1 paroissant et disparoissant alternativement3 ,cette coule de matire volcanique s'enfonce sous une partie de la ville1 btie sur le rocher2 elle reparoit dans la cave d'un marchal1 se cache et se montre encore de temps en temps en descendant dans le vallon1 c4 ,ce qu'il y a d'admirable1 c'est que la lave forme deux branches bien extraordinaires1 dont l'une s'leve sur la crte du rocher1 tandis que l'autre coupe horizontalement de grands bancs calcaires escarps1 qui sont dcouvert1 et bordent le chemin4 ,quels efforts n'-a-t-il pas fallu pour forcer cette lave se prendre une telle direction1 et se percer cette suite de rochers calcaires8 ,si cette longue coule de lave avoit eu #bjj ou #cjj toises de largeur1 je ne serois pas surpris qu'un torrent de matire en fusion de ce volume eut pu produire1 des effets extraordinaires et violens2 mais figurez-vous1 ,monsieur1 que dans les endroits les plus larges1 elle n'a tout-au-plus qu'environ #ab ou #ae pieds2 elle n'en a que #c ou #d dans certaines parties4#abf ,footnote #abf3 ,volcains ,eteints du ,vivarais1 p4 #cbh1 c4 ,this narrow stream is to be traced across the strata for more than a league and a half2 and the whole appeared to ,faujas so marvellous1 that he says he almost doubted the testimony of his senses4 ,he would have done much better1 however1 to have doubted the conclusions of his theory2 for it was by them that the phenomena before him were rendered so mysterious and incredible4 ,while he continued to regard what is described above as a stream of melted lava1 which had descended from the top of one mountain1 and climbed up the sides of the opposite1 like water in a conduit pipe1 piercing occasionally through vast bodies of solid rock1 it is no wonder that he considered as marvellous what is indeed physically impossible4 ,had his belief in the volcanic theory permitted him to see in all this1 not a superficial current1 but one of indefinite depth1 he would have beheld the object divested1 not of what was curious and interesting1 but of what was incredible or absurd1 and reduced to the same class of things with mineral veins4 ,that it belongs really to this class1 and is no more than a vein or dike of whinstone1 intersecting the strata to an unknown depth1 and most probably1 like other veins1 communicating with the mineral regions1 cannot be doubted by any one who has studied the subject of basaltine rocks1 through any other medium than the volcanic theory4 ,the ramifications which run from it into the calcareous rock1 contrived1 ,faujas says1 just as if on purpose to perplex mineralogists1 is one of the well known and characteristic appearances of basaltic veins4 #bdb4 ,it can hardly be doubted1 that the lava described by the same author as heaving up a mass of granite1#abg and including pieces of it1 is a rock of real whinstone4 ,the same may be said of many others2 and1 though ,i pretend not to affirm that there is nothing volcanic in the ,vivarais1 ,i must say1 that nothing decidedly volcanic appears in the description of that country1 but many things that are certainly of a very different origin4 ,footnote #abg3 ,volcains ,eteints du ,vivarais1 fol4 p4 #cfe1 c4 ,in the present state of geological science1 a skilful mineralogist could hardly employ himself better1 than in traversing those ambiguous countries1 where so much has been ascribed to the ancient operation of volcanic fire1 and marking out what belongs either clearly to the erupted or unerupted lavas1 and what parts are of doubtful formation1 containing no mark by which they may be referred to the one of these any more than the other4 ,such a work would contribute very materially to illustrate the natural history of the earth4 #bdc4 ,one of the most ingenious attempts to support the volcanic theory1 is the system of submarine volcanoes1 imagined by the celebrated mineralogist ,,dolomieu4 ,the phenomenon that led to this hypothesis1 was what he had observed in the hills near ,lisbon1 and still more remarkably in those of the ,val di ,noto in ,sicily1 where the basaltine rocks had regular strata incumbent on them1 and in some cases interposed or alternated with them4#abh ,it seemed from this evident1 that the strata were of later formation than the stone on which they rested2 and as they must1 on every supposition1 be held to be deposited by water1 it was concluded1 that the lava which they covered had been thrown out by volcanoes at the bottom of the sea2 that the strata had afterwards been deposited on this lava2 and that1 in some cases1 there had been frequent alternations of these eruptions and depositions4#abi ,footnote #abh3 ,mmoire de ,deodate de ,dolomieu1 sur les ,volcains ,eteints du ,val di ,noto1 en ,sicile4 ,journal de ,phys4 tom4 xxv4 7#aghd4 ,septembre47 p4 #aia4 ,footnote #abi3 ,near ,vizini1 in the ,val di ,noto1 ,dolomieu tells us1 that he counted eleven beds1 alternately calcareous and volcanic1 in the perpendicular face of a hill1 which at a distance appeared like a piece of cloth1 striped black and white2 ubi supra4 ,he has since made similar observations in the ,vicentine and in ,tyrol4 ,journal de ,phys4 tom4 xxxvii4 7#agij71 partie #b1 p4 #bjj4 #bdd4 ,though this hypothesis does certainly deliver the system of the ,volcanists from one great difficulty1 it is itself liable to insurmountable objections4 ,i shall just mention some of the principal4 #a4 ,the regular and equidistant strata that we often see covering the tops of whinstone or basaltic rocks1 could not have been deposited in the oblique and very much inclined position which they now occupy4 ,this is remarkable in the strata which cover the basaltic rock of ,salisbury ,craig1 near ,edinburgh1 at its northern extremity4 ,the strata are very regular1 and must have been deposited in a plane nearly horizontal2 yet the surface of the basaltes on which they now rest is very much inclined1 dipping rapidly to the north-east4 ,the necessity of a horizontal deposition in strata1 which1 though not now horizontal1 have their planes nearly parallel to one another1 has been proved at #ch4 #b4 ,if there is any truth in the principles established above1 even the strata themselves have not been consolidated without the action of fire4 ,by ,dolomieu's system1 therefore1 the consolidation of the strata which cover the basaltes is not accounted for4 #c4 ,there are no means furnished by the hypothesis of submarine volcanoes for bringing the basalt1 and the strata which cover it1 above the level of the sea4 ,if it is said that the waters of the sea have been drained off1 the objections are all incurred that have been stated at #cg4acj ,if it is said1 that the rocks themselves have been elevated by a force1 impelling them upwards1 we say1 that the existence of such a force1 when admitted1 furnishes another means of explaining the whole phenomenon1 namely1 that of the injection of melted matter among the strata1 the same that is used in the ,huttonian ,theory4 ,footnote #acj3 ,dolomieu adopts this supposition2 he thinks1 that the surface of the sea must have been formerly #ejj or #fjj toises above its present level4 ,ibid4 p4 #aif4 #d4 ,the phenomena of basaltic veins are not in the least explained by the hypothesis of submarine volcanoes4 ,that hypothesis1 then1 even if the foregoing objections were removed1 does not serve to explain all the facts respecting the rocks of this genus1 and wants1 of consequence1 one of the most important characters of a true theory4 ,it must be allowed1 however1 that it makes a considerable approach to such a theory1 and that the submarine volcanoes of ,dolomieu1 have an affinity to the unerupted lavas of ,dr ,hutton4 #bde4 ,though in these remarks ,i have endeavoured to expose the errors of the volcanic system1 ,i cannot but consider that system as coming infinitely nearer to the truth than the ,neptunian4 ,it has the merit of distinguishing an order of rocks1 which bears no marks of aqueous formation1 and in which the crystallized1 sparry1 or lava-like structure1 bespeaks their primeval fluidity1 and refers their origin to fire4 ,the ,neptunian system1 on the other hand1 strives to confound the most marked distinction in the mineral kingdom1 and to explain the formation1 both of the stratified and unstratified rocks1 by the operation of the same element4 ,though chargeable with this inconsistency1 it has become the prevailing system of geology2 and the arguments which support it are therefore entitled to attention4 #bdf4 ,it will no doubt be thought singular1 that the same mineralogist1 whom we have just seen exerting his ingenuity in defence of the volcanic system1 should now appear equally strenuous in defence of the ,neptunian4 ,though ,dolomieu contends for the volcanic origin of some basaltic rocks1 he does not admit that all basaltes is volcanic1 nor even all of igneous formation4 ,thus he states1 that he had examined at ,rome some of the most ancient monuments of art1 executed in basaltes1 brought from ,upper ,egypt1 and that he could discover no mark of the action of fire in any of them4#aca ,footnote #aca3 ,journal de ,physique1 tome xxxvii4 7#agij17 partie #b1 p4 #aic4 ,on the contrary1 he found that some of them consisted of green basaltes1 which changes its colour to a bronze1 when exposed even to a moderate heat1 and which therefore1 he argues1 can never have endured any strong action of fire4 ,the answer to this argument is very plain1 if we admit the effects ascribed by ,dr ,hutton to the compression which necessarily takes place in the mineral regions4 ,if indeed the heat in those regions resembled exactly that of our fires at the surface1 it would not be easy to deny the above conclusion1 which therefore certainly holds good against the volcanic origin of the ,egyptian basaltes4 ,but there is no reason why1 under strong compression1 the colouring matter of these stones might not be fixed1 and indestructible by heat1 though it can be easily volatilized or consumed when such compression is removed4 ,this argument then is against the volcanic2 but not against what has been called the ,plutonic formation of basaltes4 #bdg4 ,as to the other marks of fire which ,dolomieu sought for and did not find in the above mentioned stones1 we are not exactly informed in what they consisted4 ,if the crystallized or spathose texture that belongs to this description of stones was wanting1 the specimens were not to be considered as of the real basaltic or whinstone genus1 whatever their name or history may seem to indicate4 ,if they did possess that texture1 they had the only mark of an igneous origin that could be expected1 supposing that origin to have been in the bowels of the earth4 ,no part1 therefore1 of the observations of this ingenious mineralogist1 can be considered as inconsistent with the theory of basaltic rocks which has been laid down above4 #bdh4 ,bergman had before reasoned on this subject precisely in the same manner1 but from better data1 as the stones from which he derived his argument were in their native place3 ,trap1 says that ingenious author1 7that is whinstone17 is found in the stratified mountains of ,west ,gothland1 in a way that deserves to be described4 ,the lower stratum1 which is several ,swedish miles in circuit1 7#aj-a_/b of these miles make a degree17 is an arenaceous stone1 horizontal1 resting on granite1 and having its particles agglutinated by clay4 ,the stratum above this is calcareous1 full of the petrifactions of marine animals1 and above this is the trap4 ,these three kinds of rock compose the greater part of the mountains just mentioned1 though there are some other beds1 particularly very thin beds of marl and of clay1 which separate the middle stratum1 both from that which is under it and over it1 and are frequently so penetrated with bitumen that they burn in the fire4 ,this schistus is black2 when burnt it becomes red1 and afterwards1 when washed with water1 affords alum4 ,how can it be supposed1 he adds1 that the trap has ever been violently heated1 while the shistus on which it is incumbent retains its blackness1 which however it loses by the action even of a very weak fire8#acb ,footnote #acb3 ,bergman de ,productis ,volcaniis1 ,opuscula1 tom4 iii4 p4 #bad1 c4 ,the answer to this argument is already given4 ,the reasoning1 as in the former instance1 is conclusive only against the action of volcanic fire1 or fire at the surface2 but not against the action of heat deep in the bowels of the earth1 and under the pressure of the superincumbent ocean4 ,in such a situation1 the bituminous schistus might be in contact with the melted basalt1 and yet there might be no evaporation of the volatile1 nor combustion of the inflammable parts4 ,it does not1 however1 always happen1 that the bituminous substances1 or substances alterable by fire1 which are found in contact with basaltes1 are without any mark of having endured the operation of fire4 ,instances in which such operation is apparent are given above1 #cj2 and more will be added in the conclusion of this note4 #bdi4 ,the same mineralogist founds another argument for the aqueous formation of whin or trap on the existence of that stone in the form of veins1 included in primeval rocks3 ,invenitur hoc saxum 7trap7 in ,suecia pluribus locis1 speque in montibus primvis1 angustas implens venas1 adeo subtilis structur1 ut particul sint impalpabiles1 et1 dum niger est1 genuinum efficit lapidem ,lydium4 ,in hisce montibus1 nulla adsunt ignis subterranei vestigia4#acc ,footnote #acc3 ,opuscula1 ubi supra4 ,the phenomena here described1 namely1 a vein of compact whinstone traversing a primary rock1 is1 without doubt1 as incapable of being explained by the operation of a volcano1 as it is by that of aqueous deposition4 ,it is1 however1 a most complete proof of the original softness of the substance of which the veins consist1 and affords one of the strongest possible arguments for such an operation of fire as is supposed in the present theory4 ,the main arguments1 therefore1 which have been proposed as subversive of the igneous origin of basaltes1 are only subversive of their formation by one modification of fire1 viz4 of fire acting near the surface2 and thus the weapons which directly pierce the armour of the ,volcanist1 and inflict a mortal wound1 are easily turned aside by the superior temper of the ,plutonic mail4 #bej4 ,an argument founded on facts very similar to some of the preceding1 and leading to the same conclusion1 is employed by the mineralogist to whom the ,neptunian system owes its chief support4 ,werner1 in his observations on volcanic rocks and on basaltes1 has rested his proof of the aqueous formation of the latter1 on their interposition between beds of stone in mountains regularly stratified1 and obviously formed by water4 ,he describes an instance of this in the basaltic hill of ,scheibenberg2 and the facts1 though most of them are not uncommon1 are highly deserving of attention4 ,near the top of this hill1 and above the basaltic rock which composes the body of it1 he tells us1 that there was a sand-pit2 a circumstance which he appears to consider as not a little singular4 ,it was1 however1 at the bottom of the hill1 that he met with the appearances which chiefly attracted his notice3 ,first1 says he2 or lowest1 was a thick bank of quartzy sand1 above that a bed of clay1 then a bed of the argillaceous stone called wacke2 and upon this last rested the basaltes4 ,when ,i saw1 adds he1 the three first beds running almost horizontally under the basaltes1 and forming its base2 the sand becoming finer above1 then argillaceous1 and at last changing into real clay1 as the argil was converted into wacke in the superior part2 and1 lastly1 the wacke into basaltes2 in a word1 when ,i found a perfect transition from pure sand to argillaceous sand1 from the latter to a sandy clay1 and from this sandy clay1 through many gradations1 to a fat clay1 to wacke1 and at last basaltes1 ,i was irresistibly led to conclude1 that the basaltes1 the wacke1 the clay1 and the sand1 are all of one and the same formation2 and that they are all the effect of a chemical precipitation during one and the same submersion of this country4#acd ,footnote #acd3 ,combien je fus surpris de voir en arrivant au fond1 un epais banc de sable quartzeux1 puis au-dessus une couche d'argile1 enfin une couche de la pierre argileuse nomme ,wacke1 et sur celle-ci reposer le basalte4 ,quand je vis les trois premires couches s'enfoncer presqu' horizontalement sous le basalte1 et former ainsi sa base2 le sable devenir plus fin au-dessus1 puis argileux1 et se changer enfin en vraie argile1 comme l'argile se convertissoit en wacke dans sa partie suprieure2 et finalement la wacke en basalte2 en un mot1 de trouver ici une transition parfaite du sable pur au sable argileux1 de celui-ci l'argile sablonneuse1 et de l'argile sablonneuse1 par plusieurs gradations1 l'argile grasse1 la wacke et enfin au basalte4 ,a cette vue1 je fus sur le champ et irrsistiblement entrain penser1 7comme l'auroit t sans doute tout connoisseur impartial frapp des consquences de ce phnomne27 je fus1 dis je1 irrsistiblement entrain aux id es suivantes3 ,ce basalte1 cette wacke1 cette argile1 et ce sable1 sont d'une seule et mme formation2 ils sont tous l'effet d'une precipitation par voie humide dans une seule et mme submersion de cette contre2 les eaux qui la couvroient alors transportoient d'abord le sable1 puis deposoient l'argile1 et changoient peu--peu leur prcipitation en wacke1 et enfin en vraie basalte4--,journal de ,physique1 tom4 xxxviii4 7#agia17 ,partie i4 p4 #dae4 ,first1 as to the sand on the top of this basaltic hill1 it is most probably the remains of certain sandstone strata that originally covered the basaltic part1 but are now worn away4 ,we are therefore to consider this as an instance of a basaltic rock1 interposed between strata that are undoubtedly of marine origin4 ,in this1 however1 there is nothing inconsistent with ,dr ,hutton's theory of basaltes2 on the contrary1 it is one of the principal facts on which that theory is founded4 ,it has indeed been argued by some mineralogists1 that bodies thus contiguous must owe their origin to the same element1 and that a mineral substance cannot be of more recent formation than that which lies above it4 ,but the maxim1 that a fossil must have the same origin with those that surround it1 does not hold1 unless they have a certain similarity of structure4 ,it is1 for instance1 the want of this similarity1 that authorizes us to assign different periods of formation to mineral veins1 and to the rocks in which they are included4 ,in a succession of strata1 no one can doubt1 that the lowest were the first formed1 and the others in the order in which they lie2 but1 when between two strata of sandstone or of limestone we find an intermediate rock1 so different as to resemble lava1 and to have nothing schistose or stratified in its composition1 the same instrument cannot be supposed to have been employed in the formation of both2 nor is there any reason why we may not suppose1 that the intermediate body was interposed between the other two1 by some action subsequent to their formation4 ,it was thus that ,dolomieu concluded1 when he saw a lava-like stone interposed between calcareous strata in the ,val di ,noto1 that1 though contiguous1 these two rocks could not possibly be of the same formation2 and thus far it is certain1 that every unprejudiced observer must agree with him4 #bea4 ,but the circumstance on which ,werner seems to lay the greatest stress1 is the gradual transition from the sand to the basalt1 through the intermediate steps of clay and wacke2 this gradual transition he considers as a direct proof1 that they are all of the same formation4 ,a gradual transition of one body into another1 can only be said to take place1 when it is impossible to define their common boundary1 or to determine the line where the one begins and the other ends4 ,now1 if this be the proper notion of gradual transition1 ,i must say1 that after much careful examination1 ,i have never seen an instance1 in which such a transition takes place between whinstone and the contiguous strata4 ,the line of separation1 though in some places less evident than in others1 has1 on the whole1 been marked out with great precision2 and1 though the stones have been firmly united1 or1 as one may say1 welded one upon another1 yet1 when a fresh fracture was obtained1 the stratified and unstratified parts have rarely failed to be distinguished4 ,the fresh fracture is indeed often necessary1 for many species of whinstone get by decomposition a granulated texture at the surface1 so as hardly to be distinguished from real sandstone4 ,some of the kinds of primary schistus also1 particularly the argillaceous1 when much indurated1 have in their structure a considerable resemblance to whinstone2 they are slightly granular1 or laminated1 and have a tendency to a sparry texture4 ,where it happens that this sort of schistus and whinstone are contiguous1 it is natural to expect1 that their common boundary will be traced with difficulty1 and in many parts will be quite uncertain4 ,still1 however1 if a careful examination is made2 if the effects of accidental causes are removed2 and1 above all1 if the more ambiguous instances are compared with the more decisive1 and interpreted by them1 though single specimens may be doubtful1 we will hardly ever find that any uncertainty remains with respect to entire rocks4 #beb4 ,this general fact1 which ,i state on much better authority than that of my own observations1 viz4 on those of ,dr ,hutton1 is not given as absolutely without exception4 ,the theory of whinstone which has been laid down here1 leads us indeed to look for some such exceptions4 ,it is certain1 that the basis of whinstone1 or the material out of which it is prepared by the action of subterraneous heat1 is clay in some state or other1 and probably in that of argillaceous schistus4 ,it follows1 of consequence1 that argillaceous schistus may by heat be converted into whinstone1 or the material out of which is prepared by the action of subterraneous heat1 is clay in some state or other1 and probably in that of argillaceous schistus4 ,it follows1 of consequence1 that argillaceous schistus may by heat be converted into whinstone4 ,when1 therefore1 melted whinstone has been poured over a rock of such shistus1 it may1 by its heat1 have converted a part of that rock into a stone similar to itself2 and thus may now seem to be united1 by an insensible gradation1 with the stratum on which it is incumbent2 and phenomena of this kind may be expected to have really happened1 though but rarely1 as a particular combination of circumstances seems necessary to produce them4 ,hence it is evident1 that stones may graduate into one another1 without being of the same formation2 and that it is fallacious to conclude1 from the insensible transition of one kind of rock into another1 without any other circumstance of affinity1 that they have both the same origin4 ,i am disposed1 therefore1 to make some limitation to what is said in #gb1 where ,i have expressed an absolute incredulity as to such transitions as are here referred to4 ,the great skill and experience of the mineralogist who has described the strata at ,scheibenberg1 do not allow us to doubt of his exactness1 though some of the appearances are such as decomposition and wearing might well enough be supposed to produce4 ,the fairest way is to take ,mr ,werner's observations just as they are given us1 and to try whether they cannot be explained without the assistance of his theory4 ,in effect1 the wacken which he describes1 rests1 it would seem1 on an unconsolidated bed of clay2 and it may be supposed1 that a part of this bed has been converted into wacken by the heat of the incumbent mass1 and has thus produced the apparent gradation from the one substance to the other4 ,as the appearances of the rocks of ,scheibenberg seem to be considered by ,werner as furnishing a very strong1 and even an unexpected confirmation of his system1 ,i cannot help thinking1 that an explanation of them1 on the principles of ,dr ,hutton1 without any straining or forcing of those principles1 contributes not a little toward extending the empire of the latter over all the phenomena of geology4 #bec4 ,another fact1 which has been much infilled on of late1 in proof of the aqueous formation of basaltic rocks1 is that shells are found in them4 ,of the reality of this fact1 however1 or at least of the instances hitherto produced1 great doubts ,i think may be reasonably entertained4 ,the specimens of the supposed basaltes1 with shells included in them1 that are chiefly relied on1 are found at ,portrush in ,ireland1 a rocky promontory to the westward of the ,giant's ,causeway1 and separated from it by a considerable body of calcareous strata4 ,some of these specimens were brought to ,edinburgh about a year ago1 and were supposed1 ,i believe1 to contain an irrefragable proof of the ,neptunian origin of the basaltic promontory where they were found4 ,i went to see these specimens in company with ,lord ,webb ,seymour and ,sir ,james ,hall2 and1 on examining them carefully1 we were all of opinion1 that the stones which contained the shells1 or the impressions of the shells1 were no part of the real basaltes4 ,they were all very compact1 and had all more or less of a siliceous appearance1 such as that of chert2 they had nothing of a sparry or crystallized structure2 their fracture was conchoidal1 and but slightly uneven4 ,in two of them1 one of which bore the impression of a cornu ammonis1 the schistose texture might be distinctly perceived4 ,a specimen which accompanied them1 but in which there was no shell1 served very exactly to explain the relation between these stones and the true basaltes4 ,part of this specimen was a true basalt1 and the rest a sort of hornstone1 exactly the same with that in which the shells were1 and not unlike the jasper that is under the whinstone of ,salisbury ,crag1 and in contact with it2 so that on the whole it was evident1 that the rock containing the shells is the schistus or stratified stone1 which serves as the base of the basaltes1 and which has acquired a high degree of induration1 by the vicinity of the great ignited mass of whinstone4 ,this solution of the difficulty has since been confirmed by observations made on the spot by ,dr ,hope1 who discovered two or three alternations of the basaltic rock1 with the beds of the schistus in which the shells are contained4 #bed4 ,this also explains some observations of ,spallanzani1 made in the island of ,cerigo1 on the coast of ,greece1 the ,cythra of the ancients4#ace ,the base of that island is limestone2 but it abounds also in unstratified rocks1 which the ,italian naturalist supposes to be of volcanic origin2 but which1 if ,i mistake not1 we would regard as whinstone1 or perhaps porphyry2 and they are said to contain oyster-shells and pectinites of a large size1 perfectly mineralized4 ,these petrifactions1 however1 ,spallanzani says1 are not contained in the lava that has actually flowed1 but in stones which have only endured a slighter action of fire4 ,without the commentary afforded by the ,portrush specimens1 it would be difficult to make out any thing very precise from this description4 ,by help of the information derived from those specimens1 we may conclude1 that the condition of the shells in them1 and in the rocks of ,cerigo1 is perfectly alike2 and that1 in both cases1 the shells are involved in parts of the rock which are truly stratified1 but which have been1 in some degree1 assimilated to the basaltes by the heat which they have endured4 ,spallanzani would probably have used exactly the same terms which he employs in speaking of ,cerigo1 if he had been required to describe the petrified shells at ,portrush4 ,footnote #ace3 ,journal de physique1 tom4 xlviii4 7#agih17 p4 #bgh4 #bee4 ,in the instances just mentioned1 the petrified marine objects are not found in the real whinstone2 but if they were found in it1 when it borders on stratified rocks containing such objects1 the thing would not be at all surprising1 nor furnish any argument against the igneous consolidation of the stone4 ,if a torrent of melted matter was poured in among the strata1 by a force which at the same time broke up and disordered those strata1 nothing could be more natural1 than that this matter should contain fragments of them1 and of the objects peculiar to them4 ,in one instance1 mentioned by ,mr ,strange1 this seems actually to have taken place4 ,in the ,veronese1 a country remarkable for a mixture of limestone strata1 containing marine objects1 with volcanic or basaltine hills1 he assures us1 that he had seen a mass of stone1 which had evidently concreted from fusion1 in which the marine fossil bodies1 originally1 as he supposes1 contained in the strata1 were perfectly distinguishable1 though variously disfigured4#acf ,it may be1 that in this1 as in the foregoing examples1 it was not real basaltes1 or real lava1 which contained the shells1 but the conterminal rock2 but1 supposing it to be as ,mr ,strange represents it1 there appears to be no inconsistency between the phenomenon1 and the igneous origin of the rock in which the shells were included4 ,here1 however1 it should be remarked1 that the presence of great pressure1 to prevent the conversion of the shells into quicklime1 seems absolutely necessary2 and that the phenomenon of these basaltic petrifactions1 requires the application of heat to have been deep under the surface of the earth4 ,footnote #acf3 ,phil4 ,trans4 #agge1 p4 #be4 #bef4 ,the phenomena we have been considering1 have been selected as the most unfavourable to the igneous origin of basaltic rocks2 and we have seen1 that when duly examined1 they are not at all inconsistent with it4 ,we are now to take a view of some appearances1 that seem quite irreconcilable with the aqueous formation of these rocks4 ,where whinstone rocks are found in masses1 bounded by the strata1 and insulated among them1 they subject the ,neptunian system to great difficulties4 ,for1 supposing it true that this stone may be produced by the precipitation and crystallization of mineral substances dissolved in water1 yet it seems unaccountable1 that this effect has been so local and limited in extent1 as often to be confined to an irregular figure of a few acres1 while1 all round1 the substances deposited have had no tendency to crystallization1 and have been formed into the common secondary strata4 ,the rock of ,salisbury ,craig1 for instance1 is a mass of whinstone1 having a perpendicular face eighty or ninety feet high toward the west1 and extending from north to south with a circular sweep about #ijj yards4 ,the whole of this rock rests on regular beds of secondary sandstone1 not horizontal1 but considerably depressed toward the north-east3 the rock is loftiest in the middle1 and decreases in thickness toward each end1 terminating at its northern extremity in a kind of wedge4 ,it is covered at top1 toward that extremity1 with regular beds of sandstone1 perfectly similar to those on which it is incumbent2 and it is not improbable1 that this covering formerly extended over the whole4 ,now1 what cause can have determined the column of water1 which rested on the base at present occupied by this rock1 to deposit nothing but the materials of whinstone1 while the water on the south1 west1 and north1 was depositing the materials of arenaceous and marly strata8 ,wherefore1 within this small space1 was the precipitate every where chemical1 to use the language of ,werner1 while close to it1 on either side1 it was entirely mechanical8 ,why is there1 in this case1 no gradation8 and why is a mere mathematical line the boundary between regions where such different laws have prevailed8 ,whence also1 we may ask1 has the basaltic deposit been abruptly terminated toward the west1 so as to produce the steep face which has just been mentioned8 ,the operation of currents1 or of any motion that can take place in a fluid1 will furnish no explanation whatever of these phenomena2 yet they are phenomena far from being peculiar to a single hill2 they are among the most general and characteristic appearances in the natural history of whinstone mountains2 and a geological theory which does not account for them1 is hardly entitled to any consideration4 #beg4 ,the basaltic rock1 just described1 is also covered1 at least partly1 with strata perfectly similar to those that lie under it4 ,now1 it appears altogether unaccountable1 that after the water had done depositing the materials of the whin on the spot in question1 the former order was so quickly resumed1 and a deposition of sand1 and of the other materials of the strata1 took place just as before4 ,all this is quite unintelligible2 and the principles of the ,neptunian system seem here to stand as much in need of explanation1 as any of the appearances which they are intended to account for4 #beh4 ,the unequal thickness1 and great irregularity in the surface of the whinstone mass1 here treated of1 and of many rocks of the same kind1 is also a great objection to the notion of their aqueous formation4 ,this seems to have been perceived by ,werner1 in the instance of the rocks formerly mentioned2 and he endeavours to explain it1 by supposing1 that much of these rocks has been destroyed by waste and decomposition1 so that an irregularity of their surface1 and want of correspondence has been given to them1 which they did not originally possess4 ,in the instance of ,salisbury ,craig1 however1 we have a proof1 that the great irregularity of surface1 and the inequality of thickness1 do not always arise from these causes4 ,the thinnest part of that rock1 toward its northern extremity1 is still covered by the strata in their natural place1 and has been perfectly defended by them from every sort of wearing and decay4 ,the cuneiform shape1 therefore1 which this rock takes at its extremities1 and the great difference of its thickness at them and in the middle1 is a part of its original constitution1 and can be attributed to nothing casual1 or subsequent to its consolidation4 ,the same may be said of many other basaltic rocks1 where an inequality of thickness1 most unlike to what belongs to aqueous deposits1 is known to exist in beds of whinstone that are still deep under the surface4 ,thus the toadstone of ,derbyshire1 even where it has a thick covering of strata over it1 has been found1 by the sinking of perpendicular shafts1 to vary from the thickness of eighteen yards to more than sixty1 within the horizontal distance of less than a furlong4 ,nothing of this kind is ever found to take place in those beds of rock which are certainly known to originate from aqueous deposition1 and no character can more strongly mark an essential difference of formation4 #bei4 ,we have had frequent occasion to consider the characters of those masses of whinstone which are so often found interposed between stratified rocks4 ,these have been found in general very adverse to the ,neptunian system2 and two of them which yet remain to be mentioned1 are even more so than any of the rest4 ,where a bed or tabular mass of whinstone is interposed between strata1 and wherever an opportunity offers of seeing its termination1 if the strata under it are not broken1 it may be remarked1 that they do not abut themselves bluff and abrupt against the whin4 ,on the contrary1 if we mark the course of the stratum which covers the whinstone1 and of that which is the base of it1 we shall find they converge toward one another1 the interposed mass growing thinner and thinner1 like a wedge4 ,when the latter terminates1 the two former come in contact1 and have no stratum interposed between them4 ,thus the roof and base of the whinstone rock are contiguous beds1 that appear as if they had been lifted up and bent1 and separated by an interposed mass4 ,had the whole been an effect of simultaneous deposition1 the regular strata must have been abruptly terminated by the whin1 like two courses of different forts of masonry where they meet with one another4 #bfj4 ,from this wedge-form of the whinstone masses1 and in general from the irregularity of their surfaces1 another conclusion follows1 similar to the preceding1 and one which has been already mentioned4 ,where the surface of the interposed mass is greatly inclined to the horizon1 the strata which rest on this inclined plane1 are nevertheless as exactly parallel to that plane1 and to one another1 as if they were really horizontal4 ,it is certain1 therefore1 that they were not deposited on the same inclined plane on which they now rest2 for1 if so1 they would have been still nearly horizontal1 and by no means parallel to the inclined side of the whinstone4 ,this follows from the nature of aqueous deposition1 as already explained4 ,we have a remarkable instance of the phenomenon here referred to1 in the rock of ,salisbury ,craig1 of which mention has been so often made1 and in which almost every circumstance is united1 that can serve to elucidate the natural history of basaltic rocks4 ,the north end of that rock is in the figure of a wedge1 with its inclined side considerably steep1 and covered by strata of grit1 perfectly regular1 and parallel to the surface on which they lie4 ,the inspection of them will convince any one1 that they were not deposited by the water1 on a bottom so highly inclined as that on which they now rest4 ,they are of a structure very schistose2 their layers very thin2 so that any inaccuracy of their parallelism would be readily observed4 ,the appearances of the horizontal deposition of these strata1 are indeed so clear1 and so impossible to be misunderstood1 that the followers of the ,huttonian system would not risk much1 if they were to leave the whole theory of whinstone to the decision of this single fact1 and should agree to abandon that theory altogether1 if the ,neptunists can shew any physical or statical principle1 on which the deposition now described can possibly have been made2 or will point out the rule1 by which nature has given a structure so nicely stratified to arenaceous beds deposited on a surface so highly inclined4 ,if no such principle can be pointed out1 though we cannot conclude that the ,huttonian ,theory is true1 we certainly may conclude that the ,neptunian is false4 #bfa4 ,proofs of the igneous formation of whinstone1 still more direct1 are derived from the induration of the contiguous strata2 from their disturbance when interfered by veins of whinstone2 and from the charring of the coal which happens to be in contact with these veins4 ,these are considered above at #ff1 #fg1 c42 and it is particularly taken notice of at #ff1 that pieces of sandstone are sometimes found as if floating in the whinstone1 and1 at the same time1 greatly altered in their texture4 ,one of the best and most unequivocal instances of this sort which ,i have seen1 is to be found on the south side of ,arthur's ,seat1 near ,edinburgh4 ,the rock which composes the upper part of the hill1 on that side1 is a whinstone breccia1 such as we have many examples of1 and1 ,i believe1 very much resembling what is called a lava brecciata by the volcanic geologists4 ,the stony fragments included in this compound mass1 are for the greater part rounded2 and some of them are of whinstone1 others of porphyry1 strongly characterized by rectangular macul of feldspar1 and many seem to be of sandstone1 but so considerably altered1 as to leave it at least disputable whether they really are so or not4 ,in one part1 however1 where the face of the rock is nearly perpendicular1 a narrow ridge is seen standing out from the rest1 and of a different colour1 being more entirely covered with moss than the rock round about it1 and1 as may be presumed from that circumstance1 less liable to decomposition4 ,on examination ,i found1 that this ridge does not consist of whinstone1 but of a very hard and highly consolidated sandstone4 ,it appears to be the edge of a stratum1 of the thickness of about nine or ten inches1 and of the height of fifteen or sixteen feet4 ,it is not perfectly straight1 but slightly waved1 its general direction being nearly vertical2 and it is on both sides firmly embraced by the whinstone4 ,when broken1 it appears that this sandstone resembles in colour1 and in every thing but its greater consolidation1 and more vitreous structure1 the common grit found at the bottom of the hill1 and over all the adjacent plain4 #bfb4 ,if all these circumstances are put together1 there appears but one conclusion that can be drawn from them4 ,we have here the manifest marks of some power which could lift up this fragment of rock from its native place1 distant at least several hundred yards from its present situation1 place it upright on its edge1 encompass it with a solid rock1 of a nature quite heterogeneous to itself1 and bestow on it1 at the same time1 a great addition of solidity and induration4 ,if the mass in which this stone is now imbedded1 be supposed to have been once in fusion1 and forcibly thrown up from below1 invading the strata1 and carrying the fragments along with it1 the whole phenomena now described admit of an explanation1 and all the circumstances accord perfectly with one another2 but1 without this supposition1 they are so many separate prodigies1 which have no connection with one another1 nor with any thing that is known4 ,it is indeed impossible1 that the effects of motion and heat can be more clearly expressed than they are here1 or the subject in which these powers resided more distinctly pointed out4 #bfc4 ,the preceding facts being susceptible but of one interpretation1 are on that account extremely valuable4 ,the phenomena of ,salisbury ,craig1 near the same place1 are almost equally free from ambiguity4 ,the basaltic rock which forms that precipice1 rests on arenaceous or marly strata2 and these1 in their immediate contact with the former1 afford an instance of what is mentioned #fg1 namely1 the conversion of the strata in such situations into a kind of petrosilex1 or even jasper4 ,the line which separates the one rock from the other1 is1 at the same time1 so well defined1 as1 in the eyes even of the most determined ,neptunist1 to exclude all idea of insensible gradation4 #bfd4 ,the same rock affords some remarkable instances of the disturbance of the strata contiguous to the whinstone4 ,the beds of the former are bent upwards in several places2 and1 at one in particular1 form an arch1 with its convexity downward1 so as to make it evident1 that the force which produced this bending was directed from below upwards4 #bfe4 ,it is1 however1 where whinstone takes the form of veins1 intersecting the strata1 that the induration of the latter is most conspicuous4 ,the coast of ,ayrshire1 and the opposite coast of ,arran1 exhibit these veins in astonishing variety and abundance4 ,the strata are1 in many instances1 so reticulated by the veins1 and intersected at such small distances1 that it seems necessary to suppose1 that the fissures in them were hardly sooner made than filled up4 ,this at least is true1 if the veins are to be accounted all of the same formation2 and1 in the greatest number of instances by far1 there is no mark of the one being posterior to the other4 #bff4 ,the induration of the sides of these veins1 in some cases1 has been such1 that the sides have become more durable than the vein itself2 so that the whinstone has been worn away by the washing of the waves1 and has left the sides standing up1 with an empty space1 like a ditch1 between them4 ,one of these ,i remarked on the south side of ,brodick ,bay1 in ,arran1 which1 where it met the face of an abrupt cliff was not less than forty or fifty feet in depth4 #bfg4 ,i shall pass over whatever argument might be drawn in favour of our system1 from the slender ramifications of the veins1 and the varieties of their sizes1 from a few inches to many fathoms in diameter1 and also from the connection which they often appear to have with the great tabular masses of basaltes2 and shall only add a few remarks on the charring of coal in the vicinity of veins or masses of whinstone4 ,the connection between the charring of coal and the presence of whinstone1 was first observed by ,dr ,hutton2 and1 as far as opportunities of verifying the observation have yet occurred1 appears to be a fact no less general than it is curious and interesting4 ,in the coal mines of ,scotland1 it certainly holds remarkably1 particularly in those about ,saltcoats in ,ayrshire1 where a whinstone dike is known to stretch across the whole of the coal country1 and to be every where accompanied with blind or uninflammable coal4 ,at ,newcastle1 dikes of the same kind are met with1 and one1 in particular1 in what is called the ,walker ,colliery1 has proved the action of subterraneous fire1 to the satisfaction of mineralogists nowise prejudiced in favour of the ,huttonian system4 ,the coal found under basaltes1 in the ,island of ,sky1 has been already mentioned1 #adj4 ,to what was said concerning the fibrous structure of the parts of that fossil in immediate contact with the whin1 it may be added1 that it is also charred in those parts1 so as to have hardly any flame when it is burnt1 though further down it is of the nature of ordinary coal4 ,indeed1 if there be any truth in ,mr ,kirwan's general remark1 that it is common to find wood coal under basaltes1 it must be understood to arise from this1 that the coal in contact with the basaltes is frequently charred1 and its fibrous structure1 by that means1 rendered more visible4 #bfh4 ,it has been objected to the supposition of coal having its bituminous part driven off by the heat of the whinstone1 that this ought not1 on ,dr ,hutton's principles1 to happen in the mineral regions4 ,but it may be replied1 as has been done above1 that the local application of heat might certainly produce this effect1 and might drive off the volatile ports from a hotter to a colder part of the same stratum4 ,the bitumen has not been so volatilized and expanded as entirely to escape from the mineral regions2 but it has been expelled from some parts of a mass1 only to be condensed and concentrated in others4 ,this supposition coincides exactly with the appearances4 #bfi4 ,the native or fossil coke which accompanies whinstone1 has been distinguished into two varieties4 ,the first is the most common1 in which1 though the coal is perfectly charred1 it is solid1 and breaks with a smooth and shining surface4 ,the second is also perfect charcoal1 but is very porous and spongy4 ,this substance is much rarer than the other4 ,dr ,hutton mentions an instance of it at the mouth of the river ,ayr1 where there is a whinstone dike4#acg ,i had the satisfaction of visiting it along with him4 ,it was in the bed of the river1 below the high water mark2 the specimens had the exact appearance of a cinder4 ,footnote #acg3 ,theory of the ,earth1 vol4 i4 p4 #faa4 ,in the banks of the same river1 some miles higher up1 he found a piece of coal1 belonging to a regular stratum1 involved in whinstone1 and extremely incombustible4 ,it consumed very slowly in the fire1 and deflagrated with nitre like plumbago4 ,this be considered as the same fossil which has been described under the name of plombagine4 ,near it1 and connected with the same vein of whinstone1 was a real and undoubted plumbago4 ,from these circumstances he also concluded1 that plumbago is the extreme of a gradation1 of which fossil-coal is the beginning1 and is nothing else than this last reduced to perfect charcoal ,this agrees with the chemical analysis1 which shows plumbago to be composed of carbon1 combined with iron4 ,in confirmation of this theory1 he mentions a specimen1 in his possession1 of steatical whinstone1 from ,cumberland1 containing nodules of a very perfect and beautiful plumbago2 and he also takes notice of a mine of this last1 in ,ayrshire1 which1 on the authority of ,dr ,kennedy1 who has examined it with great care1 ,i can state as being contained1 or enveloped in whinstone2 and ,i hope the public will soon be favoured with a particular description of this very interesting spot1 by the same ingenious and accurate observer4 #bgj4 ,thus the mineralogical and chemical discoveries agree in representing coal1 blind coal1 plombagine1 plumbago1 as all modifications of the same substance1 and as exhibiting the same principle1 carbon1 in a state of greater or less combination4 ,as the last and highest term of this series should be placed the diamond2 but we are yet unacquainted with the matrix of this curious fossil1 and its geological relation to other minerals4 ,when known1 they will probably give to this substance the same place in the geological1 as in the chemical arrangement3 in the mean time1 it is hardly necessary to remark1 how well all the preceding facts agree with the hypothesis of the igneous formation of whinstone1 and how anomalous and unconnected they appear1 according to every other theory4 #bga4 ,notwithstanding all this accumulated and unanswerable evidence for the igneous formation of basaltes1 a great objection would still remain to our theory1 were it not for the very accurate and conclusive experiments concerning the fusion of this fossil1 referred to above1 #ge4 ,a strong prejudice against the production of any thing like a real stone by means of fusion1 had arisen1 even among those mineralogists1 who were every day witnesses of the stony appearance assumed by volcanic lava4 ,they still maintained1 on the authority of their own imperfect experiments1 that nothing but glass can ever be obtained by the melting of earths or of stones1 in whatever manner they are combined4 ,an ingenious naturalist1 after describing a block of basaltes1 in which he discovered such appearances1 as inclined him to admit its igneous consolidation1 rejects that hypothesis1 merely from the imaginary inability of fire to give to any substance a stony character3 ,quelque mlange1says he1 de terres que l'on suppose1 quelque soit le degr de feu que l'on imagine1 quelque soit le tems que l'on emploie1 il est trs certain que l'on n'obtiendra pas1 par le seul fluide ign1 ni basalte1 ni rien qui lui ressemble4#ach ,footnote #ach3 ,journal de ,phys4 tom4 xlix4 7#agii17 p4 #cf4 ,sir ,james ,hall's experiments have completely demonstrated the contrary of what is here asserted3 they have added much to the evidence of the ,huttonian system2 and1 independently of all theory1 have narrowed the circle of prejudice and error4 ,,note ,,xv4 #hc4 ,on ,granite4 #a4 ,granite ,veins4 #bgb4 ,it is said above1 #gg1 that granite is found in unstratified masses1 and in veins4 ,in the former of these conditions1 it constitutes entire mountains1 and forms the central ridge of many of the greatest chains that traverse the surface of the earth4 ,it is the granite of this kind that has been most generally described by travellers and mineralogists4 ,the veins have not been so much attended to1 though they are of peculiar importance for ascertaining the relation between granite and other fossils4 #bgc4 ,though ,dr ,hutton was the first geologist who explained the nature of granite veins1 and who observed with attention the phenomena which accompany them1 he is not the first who has mentioned them4 ,m4 ,besson found veins of this kind in the ,limoges1 in an argillaceous schistus1 and unconnected1 as far as appeared1 with any large mass of granite4#aci ,footnote #aci3 ,journal de ,phys4 tom4 xxix4 p4 #hi4 ,saussure met with granite veins in the ,valorsine1 but did not see them distinctly4 ,he ascribed them to infiltration4#adj ,the date of this observation is in #aggf3 ,he afterwards discovered similar appearances at ,lyons4#ada ,footnote #adj3 ,voyage au ,alpes1 tom4 i4 #eih1 #eii4 ,footnote #ada3 ,ibid4 #fja4 ,werner also1 in enumerating the substances of which veins are formed1 reckons granite as one of them4 #bgd4 ,veins of granite may be considered as of two kinds1 according as they are connected1 or not connected apparently with any large mass of granite1 it is probable1 that these two kinds of veins only differ in appearance1 and that both are connected with masses of the same rock1 though that connection is visible in some instances1 and invisible in others4 ,the distinction1 however1 whatever it be with respect to the thing observed1 is real with respect to the observer2 and1 as it is right1 in a description of facts1 to avoid every thing hypothetical1 ,i shall speak of these veins separately4 #bge4 ,veins of granite1 having no communication1 so far as can be discovered1 with any mass of the same rock1 are found in the ,western ,islands of ,scotland1 peculiarly in that of ,coll1 where they traverse the beds of gneiss and hornblende schistus1 which compose the main body of the island4 ,they are sometimes several fathoms in thickness1 obliquely intersecting the planes of the strata just mentioned1 which are nearly vertical4 ,in these veins the feldspar is predominant2 it is very highly crystallized1 and of a beautiful flesh colour4 ,many smaller veins are also to be met with in the same place2 but no large mass of granite is found1 either in this or the adjacent island of ,tiree4 #bgf4 ,the ,portsoy granite1 of which mention has been already made1 #hj1 also constitutes a vein or dike1 traversing a highly indurated micaceous schistus1 about a mile to the eastward of the little town of ,portsoy1 and not visibly connected with any large mass of the same kind4 ,more dikes than one of this granite have been observed near the same spot4 ,a similar granite is likewise found inland1 in the neighbourhood of ,huntly1 about eighteen miles south of ,portsoy2 but whether in the shape of a vein or a mass1 ,i have not been able to learn4 #bgg4 ,veins of granite are also frequent in ,cornwall1 where they are known by the name of lodes1 the same name which is applied in that country to metallic veins4 ,the granite veins frequently intersect the metallic1 and are remarkable for producing shifts in them1 or for throwing them out of their natural direction4 ,the mineral veins1 particularly those that yield copper and tin1 run nearly from east to west1 having the same direction with the beds of the rock itself1 which is a very hard schistus4 ,the granite lodes1 as also those of porphyry1 called elvan in ,cornwall1 are at right angles nearly to the former2 and it is remarked1 that they generally heave the mineral veins1 but that the mineral veins seldom or never heave the cross-veins4 ,in this country1 therefore1 the veins of granite and porphyry are posterior in formation to the metallic veins4 ,these veins of granite may perhaps be connected with the great granitic mass that runs longitudinally through ,cornwall1 from ,dartmoor to the ,land's ,end4 ,this much is certain1 that their directions in general are such1 that1 if produced1 they would intersect that mass1 nearly at right angles4 #bgh4 ,the granite veins in ,glentilt1 where ,dr ,hutton made his first observations on this subject1 are not1 ,i believe1 visibly connected with any large mass of the same rock4#adb ,the bed of the river ,tilt1 in the distance of little more than a mile1 is intersected by no less than six very powerful veins of granite1 all of them accompanied with such marks of disorder and confusion in the strata1 as indicate very strongly the violence with which the granite was here introduced into its place4 ,these veins very probably belong to the great mass of granite which is known to form the central ridge of the ,grampians further to the north2 but they are several miles distant from it1 and the connection is perhaps invisible in the present state of the earth's surface4 ,footnote #adb3 ,trans4 ,royal ,society ,edin4 ,vol iii4 p4 #gg1 c4 #bgi4 ,the second kind of granite vein1 is one which proceeds visibly from a mass of that rock1 and penetrates into the contiguous strata4 ,the importance of this class of veins1 for ascertaining the relation between granite and other mineral bodies1 has been pointed out1 #hb2 and by means of them it has been shown1 that the granite1 though inferior in position1 is of more recent formation than the schistus incumbent on it2 and that the latter1 instead of having been quietly deposited on the former1 has been1 long after its deposition and consolidation1 heaved up from its horizontal position1 by the liquid body of granite forcibly impelled against it from below4 ,it has been alleged1 in order to take off the force of the argument derived from granite veins1 that these veins are formed by infiltration1 though1 to give any probability to this supposition1 it would be necessary to show1 that water is able to dissolve the ingredients of granite2 and even if this could be done1 the direction which the veins have1 in many instances1 rising up from the granite1 is a proof1 as remarked #hb1 that they cannot be the effect of infiltration4 ,another objection has been thrown out1 namely1 that the veins here referred to are not of true granite1 according to the definition which mineralogists have given of that substance4 ,the force of a fact1 however1 is not to be lessened by a change of names1 or the use of arbitrary definitions4 ,the general fact is1 that the granitic mass1 and the vein proceeding from it1 constitute one continuous1 and uninterrupted body1 without any line of separation between them4 ,the geological argument turns on this circumstance alone2 and it is no matter whether the rock be a syenite1 a granitelle1 or a real granite4 ,the phenomenon speaks the same language1 and leads to the same conclusion1 whatever be the technical terms the mineralogist employs in describing it4 #bhj4 ,it must1 however1 be admitted1 that a difference of character is often to be observed between the granite mass and the veins proceeding from it2 sometimes the substances in the latter are more highly crystallized than in the former2 sometimes1 but more rarely1 they are less crystallized1 and1 in some instances1 an ingredient that enters into the mass seems entirely wanting in the vein4 ,these varieties1 for what we yet know1 are not subject to any general rule2 but they have been held out as a proof1 that the masses and the veins are not of the same formation4 ,it may be answered1 that a perfect similarity between substances that1 on every hypothesis1 must have crystallized in very different circumstances1 is not always to be looked for2 but the most direct answer is1 that this perfect similarity does sometimes occur1 insomuch that1 in certain instances1 no difference whatsoever can be discovered between the mass and the vein1 but they consist of the same ingredients1 and have the same degree of crystallization4 ,some instances of this are just about to be remarked4 #bha4 ,a strong objection to the supposed origin of granitic veins from infiltration1 and indeed to their formation in any way but by igneous fusion1 arises from the number of fragments of schistus1 often contained1 and completely insulated in those veins4 ,how these fragments were introduced into the fissures of the schistus1 and sustained till they were surrounded by the matter deposited by water1 is very hard to be conceived2 but if they were carried in by the melted granite1 nothing is more easily understood4 ,the following are some of the places where the phenomena of granite veins may be distinctly seen4 #bhb4 ,the island of ,arran1 remarkable for collecting into a very small compass a great number of the most interesting facts of geology1 exhibits many instances of the penetration of schistus by veins of granite4 ,a group of granite mountains occupies the northern extremity of the island1 the highest of which1 ,goatfield1 rises nearly to the height of #cjjj feet1 and on the south side is covered with schistus to the height of #aajj4 ,from thence1 the line of junction1 or that at which the granite emerges from under the schistus1 winds1 so far as ,i was able to observe1 round the whole group of mountains1 with many wavings and irregularities1 rising sometimes to a greater1 and descending sometimes to a much lower level1 than that just mentioned4 ,along this line1 particularly on the south1 wherever the rock is laid bare1 and cut into by the torrents1 innumerable veins of granite are to be seen entering into the schistus1 growing narrower as they advance into it2 and being directed1 in very many cases1 from below upwards1 they are precisely of the kind which the infiltration of water could not produce1 even were that fluid capable of dissolving the substances which the vein consists of4 ,from this south face of the mountain1 and from the bed of a torrent that intersects it very deeply1 ,dr ,hutton brought a block of schistus1 of several hundred weight1 curiously penetrated by granite veins1 including in them many insulated fragments of the schistus4 ,from this point1 the common section of the granite and schistus descends towards the west side of the mountain1 and is visible at the bottom of a deep glen1 7,glen-,rosa17 which detaches ,goatfield from the hills farther to the west4 ,the junction is laid bare at several places in the bed of the river which runs in the bottom of this glen2 and in all of them exhibits1 in a greater or less degree1 the appearances of disturbance and violence which have accompanied the injection of the granite veins4 ,many circumstances render this spot interesting to a geologist1 and1 among others1 an intersection of the granite1 a little above its junction with the schistus1 by a dike or vein of very compact whinstone4 ,the same line of junction is found on the opposite1 or north-east1 side of the mountain1 where it is intersected by another little river1 the ,sannax1 which on this side determines the base of the mountain4 ,this junction is no less remarkable than the other two4 ,the island of ,arran contains1 ,i have no doubt1 many other spots where these phenomena are to be seen2 but ,i have had no opportunity of observing them1 nor do ,i find that ,dr ,hutton met with any others in his visit to this island4 #bhc4 ,another series of granite veins is found in ,galloway1 which was first discovered by ,dr ,hutton and his friend ,mr ,clerk1 and afterwards more fully explored by ,sir ,james ,hall and ,mr ,douglas1 the present ,earl of ,selkirk4 ,the two last traced the line of separation between a mass of granite and the schistus incumbent upon it1 all round a tract of country1 about eleven miles by seven1 extending from the banks of ,loch ,ken westward2 and in all this tract they found1 that wherever the junction of the granite with the schistus was visible1 veins of the former1 from fifty yards1 to the tenth of an inch in width1 were to be seen running into the latter1 and pervading it in all directions1 so as to put it beyond all doubt1 that the granite of these veins1 and consequently of the great body itself1 which was observed to form with the veins one uninterrupted mass1 must have flowed in a soft or liquid state into its present position4#adc ,i have only farther to add1 that some of these veins are remarkable for containing granite1 not sensibly different1 in any respect1 from the mass from which they proceed4 ,footnote #adc3 ,trans4 ,royal ,society ,edin4 vol4 iii4 p4 #h4 #bhd4 ,in ,invernessshire1 between ,bernera and ,fort ,augustus1 the same phenomena occur on the north side of ,loch ,chloney1 where some granite mountains rise from under the schistus4 ,in travelling near this place1 ,lord ,webb ,seymour and myself were advertised of our approach to a junction of granite and schistus1 by finding among the loose stones on the road many pieces of schistus1 intersected with veins of feldspar and granite4 ,we walked along this junction for more than a mile2 and toward the east end1 where the road leaves it1 we saw1 in the bed of a stream that runs into ,loch ,chloney1 many beautiful specimens of granitic veins pervading the schistus1 and branching out into very minute ramifications4 #bhe4 ,the last instance ,i have to mention from my own observation1 is at ,st ,michael's ,mount in ,cornwall4 ,that mount is entirely of granite1 thrust up from under a very hard micaceous schistus1 which surrounds it on all sides4 ,at the base of it1 on the west side1 a great number of veins run off from the granite1 and spread themselves like so many roots fixed in the schistus3 they are seen at low water4 ,in the smaller veins1 the granite is of very minute1 though distinct parts2 in the larger1 it is more highly crystallized1 and is undistinguishable from the mass of the hill4 ,besides the above1 ,cornwall probably affords many other instances of the same kind1 which ,i have not had an opportunity to examine4 ,such instances may in particular be looked for at the ,land's ,end1 where a promontory1 consisting of a central part of granite1 and covered by a micaceous schistus on both sides of it1 is cut transversely by the sea coast1 and the contact of the granite and schistus of course twice exposed to view4 #bhf4 ,scotland also affords other examples of granite veins1 and some of them have been actually described4 ,mr ,jameson has taken notice of some which he saw in the bottom of the river ,spey1 at ,glen ,drummond1 in ,badenach1 and has represented them in an engraving4#add ,they traverse the strata in various directions1 and inclose pieces of the micaceous schistus2 and1 from the great number of loose blocks which he found1 exhibiting portions of such veins1 it is probable1 that they are very numerous in this quarter4 ,the same mineralogist mentions some instances of similar veins in the ,shetland ,isles4#ade ,footnote #add3 ,mineralogy of the ,scottish ,isles1 vol4 ii4 p4 #c4 ,footnote #ade3 ,ibid4 p4 #baf4 ,in ,ross-shire1 ,sir ,george ,mackenzie has observed a great variety of granite veins1 some of them of large size4 ,one of them1 in particular1 not far from ,coul1 when first discovered1 was supposed to be a single mass1 rising from under the schistus2 but1 on a more careful examination1 has been found to be a part of a great system of veins which intersects the micaceous schistus of this tract in various directions4 #bhg4 ,the granite veins are not the only proof that this stone is more recent than some other productions of the mineral kingdom4 ,specimens of granite are often found1 containing round nodules of other stones1 as1 for example1 of gneiss or micaceous schistus4 ,such is the specimen of granite containing gneiss1 which ,werner himself is said to be in possession of1 and to consider as a proof1 that the schistus is of greater antiquity than the granite4 ,such also seemed to me some pieces of granite1 which ,i met with in ,cornwall1 near the ,land's ,end2 and others which ,i saw in ,ayrshire1 in loose blocks1 on the sea coast between ,ayr and ,girvan4 ,it is impossible to deny that the containing stone is more modern than the contained4 ,the ,neptunists indeed admit this to be true1 but allege1 that all granite is not of the same formation2 and that1 though some granite is recent1 the greater part boasts of the highest antiquity which belongs to any thing in the fossil kingdom4 ,this distinction1 however1 is purely hypothetical2 it is a fiction contrived on purpose to reconcile the fact here mentioned with the general system of aqueous deposition1 and has no support from any other phenomenon4 #b4 ,granite of ,portsoy4 #bhh4 ,the granite of ,portsoy is one of the most singular varieties of this stone1 and is remarkable for this circumstance1 that the feldspar is the substance which has assumed the figure of its proper crystal1 and has given its form to the quartz1 so that the latter is impressed both with the acute and obtuse angles belonging to the rhombic figure of the former4 ,the angular pieces of quartz thus moulded on the feltspar1 and ranged by means of it in rows1 give to this stone the appearance of rude alphabetical writing4 ,now1 ,dr ,hutton argued1 that substances precipitated from a solution1 and crystallizing at liberty1 cannot be supposed to impress one another in the manner here exemplified2 and that they could do so only when the whole mass acquired solidity at the same time1 or at the same time nearly4#adf ,such simultaneous consolidation can be produced in no way that we know of1 but by the cooling of a mass that has been in fusion4 ,footnote #adf3 ,theory of the ,earth1 vol4 i4 ,p4 #ajd4 #bhi4 ,a granite1 brought from ,daouria by ,m4 ,,patrin1 and described by him in the ,journal de ,physique for #agia1 p4 #bie1 under the name of pierre graphique1 seemed to ,dr ,hutton to have so great a resemblance to the granite of ,portsoy1 that he ventured to consider them both as the same stone1 and as both containing quartz moulded on feltspar4#adg ,it should seem1 however1 from further explanations1 which ,m4 ,patrin has since given1 but ,dr ,hutton was mistaken in his conjecture1 and that1 in the pierre graphique of the former mineralogist1 the quartz gives its form to the feltspar1 preserving in its crystals their natural angle of #abj degrees#adh ,it is impossible1 ,i think1 to doubt of the accuracy of this statement2 and the graphical stone of ,portsoy must therefore be admitted to differ materially from that of ,daouria4 ,they are not1 however1 without some considerable affinity1 besides that of their outward appearance2 for1 though the quartz in the former is generally moulded on the feltspar1 the feldspar is also occasionally impressed by the quartz1 and sometimes even included in it4 ,they may be considered as varieties of the same species of granite2 and the pierre graphique of ,corsica is probably a third variety1 different from them both4 ,footnote #adg3 ,trans4 ,royal ,society ,edin4 vol4 iii4 p4 #hc4 ,footnote #adh3 ,journal ,britainnique1 7of ,geneva17 #agih1 vol4 viii4 ,sciences et ,arts1 p4 #gh4 #bij4 ,it would seem1 however1 that all these stones lead exactly to the same conclusion4 ,m4 ,patrin describes his specimen as containing quartz crystals1 that are for the most part only cases1 having their interior filled with feltspar ,le feltspath en masse contient des crysteaux quartzeux1 qui n'ont le plus souvent que la carcasse1 et dont l'interieur est rempli de feltspath2 souvent il manque ces carcasses quelques unes de leurs faces1 et souvent la section de cette pierre dans un sens transversal aux crysteaux1 presente une suite de figures qui sont des portions d'hexagones1 et qui ne resemblent pas mal des caractres ,hebraiques4#adi ,footnote #adi3 ,journal ,britannique1 ,ibid4 ,these imperfect hexagonal cases of quartz1 filled with feldspar1 certainly indicate the crystallization of substances1 which all assumed their solidity at the same time1 and1 in doing so1 constrained the figures of one another4 ,to use the words of ,dr ,hutton1 whether crystallizing quartz inclose a body of feltspar1 or concreting feltspar determine the shape of fluid quartz1 particularly if we have1 as is here the case1 two solid bodies including and included1 it amounts to a demonstration1 that those bodies have concreted from a fluid state of fusion1 have not crystallized1 in the manner of salts1 from a solution4#aej ,footnote #aej3 ,trans4 ,royal ,society ,edin4 ubi supra1 p4 #hd4 #bia4 ,the quartz in granite so generally receives the impressions of all the other substances1 particularly of the feldspar and schorl1 and appears to be so passive a body1 that it has been doubted by some mineralogists1 whether in this stone it ever assumes its own figure1 except where cavities afford room for its crystallization4 ,but it is certain that1 beside the ,daourian granite just mentioned1 there are others1 in which the quartz is completely crystallized4 ,of this sort are some specimens1 found in a granite vein on the west side of the hill of ,st ,agnes1 in ,cornwall4 ,the vein traverses the primitive schistus1 of which that hill consists1 from south to north nearly3 the stone is much decomposed1 and the feldspar in general is almost reduced to the state of clay4 ,in this decomposed mass1 quartz crystals are found1 having the shape of double hexagonal pyramids1 perfectly regular and complete4 ,the side of the hexagon1 which is the base of the two opposite pyramids1 varies from half a tenth to a tenth of an inch in length1 and is the same with the altitude of each of the pyramids4 ,in some few specimens1 the two pyramids do not rest on the same base1 but are separated by a very short1 though regular1 hexagonal prism4 ,the surfaces of these crystals are rough1 and somewhat opaque1 with slender spicul of schorl frequently traversing them4 ,this roughness is occasioned by slight furrows on the surface of the crystal1 very regularly disposed1 and parallel to one another1 being without doubt impressions from the thin plates of the feldspar1 which surrounded the crystal1 and slightly indented it4 ,they very much resemble some impressions1 remarked by ,dr ,hutton in the granite of ,portsoy1 and ascribed by him also to a similar cause4 ,he has represented these in his ,theory of the ,earth1 vol4 i4 plate ii4 fig4 #d4 ,the action and reaction of two crystallizing bodies1 hardly admits of a stronger and more unequivocal expression1 than in these two instances4 ,where the granite was little decomposed1 the quartz was not easily disengaged from the mass it was imbedded in1 and often broke in pieces before it could be extricated4 ,the crystallization of the quartz1 therefore1 would not have been discovered1 but for the decomposition of the feltspar2 and it is probable1 that similar crystallizations exist in many granites where they are not perceived4 #bib4 ,some mineralogists are inclined to think1 that the regular crystallization of quartz is to be found only in what they call secondary granites1 or in those that are of a formation subsequent to the great masses which constitute the granite mountains4 ,it is indeed true1 that in the instances given here1 both from ,cornwall and ,daouria1 the granites containing quartz crystals are from veins that intersect the primary schistus1 and are therefore1 on every hypothesis1 of a formation subsequent to that schistus4 ,but it does not follow from thence1 that they are less ancient than the great masses of unstratified granite2 with these last they are most probably coval1 nor can there be any reason for thinking the crystallization of quartz a mark of more recent formation than that of feltspar4 #c4 ,stratification of ,granite4 #bic4 ,what are the various modes in which granite exists1 is a question not absolutely decided among mineralogists4 #a4 ,that it exists as a schistose stone of a fissile texture1 in gneiss and veined granite1 is on all hands admitted1 though in this state the name of granite is generally withheld from it4 #b4 ,that it exists often without any indication of a fissile texture1 and altogether unstratified1 is likewise acknowledged4 #c4 ,that it is found in veins1 intersecting the strata1 has been shown above4 ,the only mode of its existence subject to dispute1 is that in which it is said to be stratified in its outward configuration1 but not schistose in its texture4 ,on this point mineralogists do not perfectly agree3 ,dr ,hutton did not think that this was a state in which granite ever appears4 ,when not schistose in its structure1 he supposed it to be unstratified altogether2 and he considered it as a body which1 like whinstone1 was originally in a state of igneous fusion1 and1 in that condition1 injected among the strata4 ,the school of ,werner1 on the other hand1 maintain1 that granite1 if not always1 is generally stratified1 and disposed in beds1 sometimes horizontal1 though more frequently vertical1 or highly inclined4 ,in forming an opinion where there are great authorities on opposite sides1 a man must trust chiefly to his own observations1 and ought to esteem himself fortunate if these lead to any certain conclusion4 ,mine incline me to differ from ,dr ,hutton1 on the one hand1 and from the ,neptunists1 on the other1 as they convince me1 that granite does form strata where it has no character of gneiss2 and1 at the same time1 induce me to suspect1 that the stratification ascribed by the ,neptunists to the granite mountains1 is1 in many instances1 either an illusion1 or at least something very different from what1 in other stones1 is accounted stratification4 #bid4 ,the first example ,i ever saw of granite that was stratified1 and yet had no character of gneiss1 was at ,chorley ,forest1 in ,leicestershire4 ,the greater part of that forest has for its base a hornstone schistus1 primary and vertical2 and1 on its eastern border1 particularly near ,mount ,sorrel1 are beds of granite1 holding the same direction with those of the schistus4 ,the stone is a real granite2 it has nothing in its internal structure of a schistose or fissile appearance2 and its beds1 which it is material to remark1 are no thicker than those of the hornstone strata in the neighbourhood4 ,this granite is remarkable1 too1 for being close to the secondary sandstone strata2 ,i did not see their contact1 but traced them within a small distance of one another2 so that ,i think it is not likely that any body of rock intervenes4 ,at the same time that ,i state my belief of this rock of granite being in regular strata1 ,i must acknowledge1 that a very intelligent mineralogist1 who viewed these rocks at the same time1 and whose eye was well practised in geological observation1 remained in doubt concerning them4 #bie4 ,another instance of a real granite1 disposed in regular beds1 but without any character of gneiss1 is one which ,i saw in ,berwickshire1 in ,lammermuir1 near the village of ,priestlaw4 ,the little river of ,fassnet cuts the beds across1 and renders it easy to observe their structure4 ,the beds are not very thick2 they run from about ,s4,s4,w4 to ,n4,n4,e4 like the schistus on either side of them4 ,i was in company with ,sir ,james ,hall when ,i saw these rocks2 we examined them with a good deal of attention1 and traced them for more than a mile in the bed of the river2 and1 if ,i mistake not1 our opinions concerning them were precisely the same4 #bif4 ,what exists in two instances may exist in many1 and1 after these observations1 ,i should be guilty of great inconsistency1 in refusing to assent to the accounts of ,pallas1 ,de ,luc1 ,saussure1 and many other mineralogists1 who so often represent granite as formed into strata4 ,in some cases1 however1 it is certain1 that the stratification they describe is extremely unlike that in the two instances just mentioned1 and indeed very unlike any thing that is elsewhere known by the name of stratification4 ,for example1 the stratification must be very ambiguous1 and very obscurely marked1 that was not discovered till after a series of observations1 continued for more than twenty years1 by a very skilful and distinguishing mineralogist4 ,yet such undoubtedly is the stratification of ,mont ,blanc1 and of the granite mountains in its neighbourhood1 as it escaped the eyes of ,saussure1 in the repeated visits which he made to them1 during a period of no less extent than has just been mentioned4 ,it was not till near the conclusion of those labours1 to which the geologists of every age will consider themselves as highly indebted1 that1 having reached the summit of ,mont ,blanc1 he perceived1 or thought that he perceived1 the stratification of the granite mountains4 ,the ,aiguilles or ,needles which border the valley of ,chamouni1 and even ,mont ,blanc itself1 appeared to be formed of vast tabular masses of granite1 in position nearly vertical1 and so exactly parallel1 that he did not hesitate to call them by the name of strata4 ,till this moment1 these same mountains1 viewed from a lower point1 had been regarded by him as composed of great plates of rock1 nearly vertical indeed1 but applied1 as it were1 round an axis1 and resembling the leaves of an artichoke2#aea and the fissures by which they are separated from one another1 had been considered as effects of waste and degradation4 ,but now1 7says he1 speaking of the view from the top of ,mont ,blanc17 ,i was fully convinced1 that these mountains are entirely composed of vast plates of granite1 perpendicular to the horizon1 and directed from ,n4,e4 to ,s4,w4 ,three of these plates1 separated from each other1 formed the top of the ,aiguille du ,midi1 and other similar plates1 decreasing gradually in height1 compose its declivity to the south4#aeb ,footnote #aea3 ,voyages aux ,alpes1 tom4 ii4 #iaj1 c4 ,footnote #aeb3 ,voyages aux ,alpes1 tom4 iv4 #aiif4 #big4 ,saussure was so strongly impressed with the appearances of what he accounted regular stratification1 such as water only can produce1 and such as must have been in the beginning horizontal1 that1 placed as he now was1 on one of the highest points of the earth's surface1 he formed the bold conception1 that the summit on which he was standing had been once buried under the surface1 to the depth at least of half the diameter of the mountain1 and horizontally distant from its present place by a line not less than the whole height of the mountain2 the granite beds which compose that mountain1 having been raised by some enormous power from their horizontal position1 and turned as on an axis1 till they were brought into the vertical plane4 ,in this notion1 which suits so well with the nature of mountains really composed of vertical strata1 and which does credit to the extent of ,saussure's views1 it is wonderful that he did not see the overthrow of the geological system be had adopted1 which is provided with no means whatsoever of explaining these great effects4 ,such1 then1 were the ideas suggested to ,saussure1 by viewing the mountains of the ,alps from the highest of their summits4 ,his great experience1 his accurate knowledge of the objects before him1 and the power he had acquired of dissipating those illusions1 to which1 in viewing mountainous tracts1 the eye is peculiarly subject1 all conspire to give great weight to his opinion4 ,yet1 as this opinion is opposed by that which he himself had so long entertained1 before it can be received with perfect confidence1 it will require to be verified by new observations4 ,it seems certain1 that the beds of rock here described1 differ from all ordinary strata1 both horizontal and vertical1 in the circumstance of their vast thickness1 three of them being so large as to form the main body of a mountain4 ,their parallelism cannot easily be ascertained2 and they have at best but a very slight resemblance to such beds as water is known to produce4 #bih4 ,their parallelism is difficult to be ascertained2 for1 on account of the magnitude and inaccessibility of the objects1 it is impossible to place the eye in any situation1 where it shall not be much nearer to one part of the planes whereof the parallelism is to be estimated1 than to another4 ,indeed1 one can perceive a cause which may have rendered the parallelism of the plates of granite which compose the aiguilles1 more accurate in appearance than in reality1 when viewed from a point so elevated as the summit of ,mont ,blanc4 ,for1 even on the supposition that the comparison of those plates to leaves of artichokes was just1 and that the planes of their separation converged toward one another1 in ascending to the top1 when they were viewed from a point more elevated than that top1 this convergency would be diminished1 and1 by the force of the perspective1 might even be converted into parallelism4 ,we cannot at present ascertain what effect this cause of deception may have actually produced4 #bii4 ,the observations of ,saussure concerning the stratification of granite1 are not1 however1 in all instances1 liable to these objections2 and it seems to be on much less exceptionable grounds that he pronounces the granite of ,st ,gothard to be stratified4 ,the gneiss and micaceous schistus which constitute the lower part of that mountain1 are succeeded by a granite without any schistose appearance1 but divided into large plates1 exactly parallel to the beds of the former gneiss4 ,these he regards as real strata4 ,on studying them in detail1 he says1 considerable irregularities were to be observed1 but not greater than in the case of limestone or micaceous schistus4#aec ,it may be inferred from this1 that these plates of granite are not so thick but that they admit of comparison with beds that are known with certainty to be of aqueous formation1 and ,i am therefore disposed to believe1 that the granite of ,st ,gothard1 in this part at least1 is stratified4 ,the transition from gneiss to granite en masse1 is not uncommon1 as ,saussure has observed in other instances1 and as we are just about to consider more particularly4 ,footnote #aec3 ,voyages aux ,alpes1 tom4 iv4 #ahcj4 #cjj4 ,in the mountains of our own country1 some difficulties concerning the stratification of granite have also occurred4 ,in ,arran1 for instance1 the mountain of ,goatfield1 which ,i have mentioned above as affording an instance of granite sending out many veins into the schistus1 and rivetted1 as it were1 by means of them to the superincumbent rock1 when ,i visited it1 with1 a view of verifying on the spot the interesting observations which ,dr ,hutton had there made1 appeared to me to be without any vestige of stratification in its granitic part1 as did also the whole group of mountains to which it belongs4 ,it was1 therefore1 not without a good deal of surprise1 that ,i lately read1 in an account of that island1 by a very accurate and ingenious mineralogist1 that ,goatfield consists of stratified granite4#aed ,the impression which the appearance of that mountain made on my mind1 is just the reverse2 and though ,i saw large tabular masses1 sometimes nearly vertical1 separated by fissures1 they appeared to be much too irregular1 too little extended in length and height1 and vastly too much in thickness1 to be reckoned the effects of stratification4 ,for all this1 ,i would by no means be understood to set my observations in opposition to those of ,mr ,jameson4 ,in my visit to ,arran1 ,i did not direct my inquiries much toward this point2 the general appearance of the rocks did not suggest the necessity of doing so1 and ,i was not perfectly aware how much the stratification of granite had been insisted on by some mineralogists2 so that ,i applied myself entirely to study some other of the interesting phenomena which this little island offers in so great abundance4 ,i therefore carry my confidence in the appearances which seemed to indicate a want of stratification in the granite of ,arran no further than to remain sceptical both as to ,mr ,jameson's conclusions and my own1 till an opportunity shall occur of verifying the one or the other by actual observation4 ,footnote #aed3 ,mineralogy of the ,scottish ,isles1 vol4 i4 p4 #ce1 #cf4 #cja4 ,the stratification of granite1 though it made no part of ,dr ,hutton's system1 does by no means embarrass his theory with any new difficulty4 ,rocks1 of which the parts are highly crystallized1 are already admitted as belonging to the strata1 and are exemplified in marble1 gneiss1 and veined granite4 ,in the two last1 we have not only stratification1 but a schistose1 united with a crystallized structure1 and the effects of deposition by water1 and of fluidity by fire1 are certainly no where more singularly combined4 ,the stratification of these substances is therefore more extraordinary than even that of the most highly crystallized granite4 ,neither the one nor the other can be explained but by supposing1 that while such a degree of fluidity was produced by heat1 as enabled the body when it cooled to crystallize1 the whole mass was kept in its place by great pressure acting on all sides1 so that the shape was preserved as originally given to it by the sea4 ,as we cannot1 however1 suppose1 that the intensity of the heat1 or the fusibility of the substance through all the parts of a stratum1 were precisely the same1 we may expect to find in the same stratum1 or in the same body of strata1 that in some parts the marks of stratification are completely obliterated while in others they remain entire4 ,it is thus that veined granite1 of what ,i think should be called granitic schistus1 often graduates into granite in mass1 that is1 granite without any schistose or fissile texture4 ,saussure says1 that to be veined or not veined1 is an affection of granite1 that seems1 in many cases1 accidental2#aee as1 in the midst of rocks of that substance1 most clearly fissile1 large portions appear without any vestige of stratification4 ,of this phenomenon1 which is frequent in the ,alps1 instances are also to be met with in the granite rocks of ,scotland1 and the adjacent isles2 and ,i know that ,dr ,hope1 in a mineralogical excursion which he lately made among the ,hebrides1 observed many interesting and curious examples of it4 ,indeed1 when rocks were so much fused as to crystallize1 and so compressed1 at the same time1 as to remain stratified1 they were evidently on the verge of change2 two opposite forces were very nearly balanced1 and each carried as far as it could go without entirely overcoming the other2 so that a small alteration in the conditions may have made a great alteration in the effects4 ,hence a sudden transition from a stratified to an unstratified texture1 which is only found in rocks highly crystallized1 and such as have endured the most violent action of the mineralizing powers4 ,footnote #aee3 ,voyages aux ,alpes1 tom4 iv4 #badc4 #cjb4 ,now1 though the stratification of granite1 or the mixture of the stratified with the unstratified rocks of that genus1 is not only reconcilable with the principles of the ,huttonian geology1 but might even have been deduced as a corollary from those principles1 before it was actually observed1 it may be considered as inconsistent with the theory of granitic veins that has just been given4 ,a stratum1 though soft or fluid1 could not invade the surrounding strata with violence1 nor send out veins to penetrate into them4 ,it might1 if1 strongly compressed by another stratum less fluid than itself1 fill up any fissures or cracks that were in that other1 but this would hardly produce1 such large veins1 and of such considerable length1 as often3 penetrate from the granite into the schistus1 nor could it give rise to any appearance of disturbance4 ,if1 therefore1 veins were found proceeding from such stratified granite as that of ,chorley ,forest or ,lammermuir1 ,i should think1 that the explanation of them was still a desideratum in geology4 ,the ,neptunian theory of infiltration would indeed be as applicable to them as to any other veins2 for it is but little affected by the condition of the phenomena to be explained4 ,indeed1 it is very difficult to set any limits to the explanations which this theory affords2 and it would certainly puzzle a ,neptunist1 to assign any good reason why infiltration has not produced veins of one schistus running into another1 or veins of schistus running into granite1 as well as of granite running into1 schistus4 ,he will find it a hard task to restrain the activity of his theory1 and to confine its explanations to those things that really exist4 #cjc4 ,as the ,huttonian system cannot boast of theories of equal versatility1 it would be not a little embarrassed to account for veins of great magnitude proceeding from a rock distinctly stratified1 and accompanied with marks of having disturbed the rocks through which they pass4 ,i am1 however1 inclined to believe1 that this embarrassment will never occur2 and that the granite veins do not proceed from the rocks that are really stratified1 but from such as have never been deposited by water1 and where the appearances of stratification1 if there are any1 are altogether illusory4 ,this anticipation1 however1 requires to be verified by future observation2 and it remains to be seen1 whether granitic veins ever accompany real granitic strata1 or are peculiar to those in which the appearances of regular beds are either ambiguous1 or are entirely wanting4 ,the decision of this question is an object highly worthy of the attention of geologists4 #cjd4 ,an argument1 directed at once against the igneous origin and unstratified nature of all granite1 is given in a work already mentioned4 ,if granite had flowed from below1 how does it happen1 that1 after it had burst through the strata of micaceous schistus1 c4 it did not overflow the neighbouring country8 ,if this hypothesis were true1 ,mont ,blanc could never have existed4#aef ,footnote #aef3 ,mineralogy of the ,scottish ,isles1 vol4 ii4 p4 #aff4 ,a theory is never more unfairly dealt with1 than when those parts are separated which were meant to support one another1 and each left to stand or fall by itself4 ,this1 however1 is precisely what is done in the present instance2 for ,dr ,hutton's theory of granite would not deserve a moment's consideration1 if it were so inartificially constructed1 as to suppose that granite was originally fluid1 and yet to point out no means of hindering this fluid from diffusing itself over the strata1 and settling in a horizontal plane4 ,the truth is1 that his theory1 at the same time that it conceives this stone to have been in fusion1 supposes it to have been1 in that state1 injected among the strata already consolidated2 to have heaved them up1 and to have been formed in the concavity so produced1 as in a mould4 ,thus ,mont ,blanc1 supposing that it is unstratified1 is understood to consist of a mass that was melted by subterraneous heat under the strata1 and being impelled upwards by a force1 that may stand in some comparison with that which projected the planets in their orbits1 heaved up the strata by which it was covered1 and in which it remained included on all sides4 #cje4 ,the covering of strata1 thus raised up1 may have been burst asunder at the summit1 where the curvature and elevation were the greatest2 but the melted mass underneath may have already acquired solidity1 or may have been sustained by the beds of schistus incumbent on its sides4 ,this schistus1 forming the exterior crust1 was immediately acted on by the causes of waste and decomposition1 which have long since stripped the granite of a great part of its covering1 and are now exercising their power on the central mass4 ,that even ,mont ,blanc itself1 as well as other unstratified mountains1 was once covered with schistus1 will appear to have in it nothing incongruous1 when we consider the height to which the schistus still rises on its sides1 or in the adjacent mountains2 and when we reflect1 that1 from the appearances of waste and degradation which these mountains exhibit1 it is certain1 that the schistus must have reached much higher than it does at present4 ,it is obvious1 therefore1 that when the corresponding parts are brought together1 and placed in their natural order1 no room is left for the reproach1 that this system is inconsistent with the existence of granite mountains4 ,i have no pleasure in controversial writing2 and1 notwithstanding the advantages which a weak attack always gives to a defender1 ,i cannot but regret1 that ,dr ,hutton's adversaries have been so much more eager to refute than to understand his theory4 ,illustration #cjf4 ,a remark which ,dr ,hutton has made on the quantity of granite that appears at the surface1 compared with that of other mineral bodies1 has been warmly contested4 ,having affirmed1 that the greater part of rocks bear marks of being formed from the waste and decomposition of other rocks1 he alleges that granite1 7a stone which does not contain such marks7 does not1 for as much as appears from actual observation1 make up a tenth1 nor perhaps even a hundredth part of the mineral kingdom4#aeg ,mr ,kirwan contends1 that this is a very erroneous estimate1 and that the quantity of granite visible on the surface1 far exceeds what is here supposed4#aeh ,the question is certainly of no material importance to the establishment of ,dr ,hutton's theory3 it is evident1 too1 that an estimation1 which varies so much as from a tenth to a hundredth part1 cannot have been meant as any thing precise2 yet it may not be quite superfluous to show1 that the truth probably lies nearer to the least than the greatest of the limits just mentioned4 ,footnote #aeg3 ,theory of the ,earth1 vol4 i4 p4 #baa4 ,footnote #aeh3 ,geol4 ,essays1 p4 #dhj4 #cjg4 ,though granite forms a part1 generally the central part1 of all the great chains of mountains1 it usually occupies a much less extent of surface than the primary schistus4 ,thus in the ,alps1 if a line be drawn from ,geneva to ,ivrea1 it will be about eighty-five geographical miles in length1 and will measure the breadth of this formidable chain of mountains1 at the place of its greatest elevation4 ,now1 from the observations of ,saussure1 who crossed the ,alps exactly in this direction1 it may be collected1 that less than nine miles of this line1 or not above a tenth part of it1 in the immediate vicinity of ,mont ,blanc1 is occupied by granite4 #cjh4 ,in some sections of the ,alps1 no granite at all appears4 ,thus1 in the route from ,chambery to ,turin1 across ,mont ,cenis1 which measures by the road not less than ninety miles1 no granite is found1 at least of that kind which is distinctly in mass1 and different from gneiss or veined granite4#aei ,footnote #aei3 ,voyages aux ,alpes1 tom4 iii4 #aaij1 c4 #cji4 ,in some other places of the same mountains1 the granite is more abundant4 ,a line from the lake of ,thun1 along the course of the ,aar1 and over the mountains to the upper end of ,lago ,maggiore1 crosses a very elevated tract1 and passes by the sources of the ,rhone1 the ,rhine1 and the ,tessino1 which last runs into the ,po4 ,a good deal of granite is discovered here1 in the mountains of ,grimsel and ,st ,gothard2 but by far the greater part of it is the veined granite1 the granite in mass being confined chiefly to the north side of the ,grimsel4 ,both together do not occupy more than one-third of the line1 and therefore the latter less than one-sixth4 #caj4 ,the essay on the mineralogy of the ,pyrenees1 by the ,abb ,,palasso1 contains a mineralogical chart of those mountains4 ,from this chart ,i have found1 by computation1 that the granite does not occupy one-fifth of the horizontal surface on the north side of the ridge1 reckoning from one end of it to the other4 ,indeed1 many great tracts1 even of the central parts of the ,pyrenees1 contain no granite whatsoever2 and not a few of the highest mountains consist entirely of calcareous schistus4 ,a large deduction should be made from the fraction #a_/e on account of the substances unknown1 which1 from the construction of the chart1 are often confounded with the granitic tract4 #caa4 ,i might add other estimations of the same kind1 all confessedly rude and imperfect1 but still conveying1 by means of numbers1 a better idea of the limit to which our knowledge approximates1 than could be done simply by words2 and1 on the whole1 it would appear1 that if we state the proportion of granite to schistus to be that of one to four1 we shall certainly do no injustice to the extent of the former4 ,it remains to form a rough estimate from maps1 and from the accounts of travellers1 of what proportion of the earth's surface consists of primary1 and what of secondary rocks4 ,after supplying the want of accurate measurement by what appeared to me the most probable suppositions1 ,i have found1 that about #a_/ah of the surface of the old continent may be conceived to be occupied by primitive mountains2 of which1 if we take one-fifth1 we have #a_/ij for the part of the surface occupied by granite rocks1 which differs not greatly from the least of the two limits assigned by ,dr ,hutton4 #cab4 ,in estimating the granite of ,scotland1 ,dr ,hutton has certainly erred considerably in defect1#afj and ,mr ,kirwan1 who always differs from him1 is here nearest the truth2 though he is right purely by accident1 as the information on which he proceeds is vague and erroneous4 ,footnote #afj3 ,dr ,hutton in this case no doubt made a very loose estimate4 ,he says1 the granite does not perhaps occupy more than a #ejj;dth part of the whole surface4 ,the whole surface of ,scotland is not much more than #bc1jjj geographical miles1 the #ejj;dth part of which is exactly #df2 and this is exceeded by the granite in ,kirkcudbrightshire done1 as may be gathered from what is said #bhc4 ,the places in ,scotland where granite is found1 are very well known2 but the extent of some of the most considerable of them is not accurately ascertained4 ,in the southern parts1 except the granite of ,galloway1 which is found in two pretty large insulated tracts1 there is no other of any magnitude4 ,the granite of the north extends over a large district4 ,if we suppose a line to be drawn1 from a few miles south of ,aberdeen to a few miles south of ,fort ,william1 it will mark out the central chain of the ,grampians in its full extent1 passing over the most elevated ground1 and by the heads of the largest rivers1 in ,scotland4 ,along this line there are many granite mountains1 and large tracts in which granite is the prevailing rock4 ,there are1 however1 large spaces also in which no granite appears1 though1 if we were permitted to speak theoretically1 and if the question did not entirely relate to a matter of observation1 we might suppose1 that1 in no part of this central ridge is the granite far from the surface1 notwithstanding that in some places it may be covered by the schistus4 #cac4 ,a great part of the ,grampian mountains is on the south side of the line just mentioned1 but hardly any granite is found in this division of them1 except such veins as those of ,glentilt4 ,on the north side of the line1 the granite extends in various directions2 and1 if from ,fort ,william a line is drawn to ,inverness1 the quadrilateral figure1 bounded on two sides by these lines1 and on the other two by the sea1 will be found to contain much granite1 and many districts consisting entirely of that stone4 ,this is in fact the great granite country of ,scotland3 it is a large tract1 containing about #cagj square geographical miles1 or about a seventh part of the whole3 but the proportion of it occupied by granite cannot at present be ascertained with any exactness1 nor will1 till some mineralogist shall find leisure to examine the courses of the great rivers1 the ,dee1 the ,spey1 c4 which traverse this country4 ,if we call it one-fourth of the whole surface1 its extent is certainly not underrated1 and will amount to #gij square miles nearly2 to which adding #aej1 as a very full allowance for all the other granite contained in ,scotland1 exclusive of the isles1 we shall have #idj square miles1 between a twenty-fourth and twenty-fifth part of the surface of the whole4 ,this computation1 it must be observed1 aims at nothing precise1 but ,i think it is such1 that a more accurate survey would rather diminish than increase the proportion assigned in it to the granite rock4 #cad4 ,this result may perhaps fall as much short of ,mr ,kirwan's notion1 as it exceeds the estimate made by ,dr ,hutton4 ,if it shall not1 and if the former has1 in this instance1 come nearest the truth1 it cannot be ascribed to the accuracy of his information1 or the soundness of the principles which directed his research4 ,mr ,,williams1 whom he quotes1 was a miner1 of great skill and experience in some branches of his profession1 to which1 if he had confined himself1 he might have written a book full of useful information4 ,what he says on the subject of granite1 is1 in the main ,i believe just2 but it is far too general to authorize the conclusion which ,mr ,kirwan derives from it4 ,dr ,ash1 for whose judgment ,i have great respect1 cannot1 ,i think1 have meant1 when he used the expression granitic rocks1 to describe granite strictly so called4 ,he says1 in the passage quoted by ,mr ,kirwan1 that from ,galloway1 ,dumfries1 and ,berwick1 there is a chain of mountains1 commonly schistose1 but often also granitic4 ,now1 the fact is1 that the great belt of primary rock1 here alluded to1 which traverses the south of ,scotland1 consists of vertical schistus of various kinds2 but except in ,galloway1 and again in ,lammermuir1 near ,priestlaw1 it appears1 as already mentioned1 to contain no granite whatsoever4 ,if the ,german mineralogist quoted by ,mr ,kirwan1 when he says that the ,grampian mountains consist of micaceous limestone1 gneiss1 porphyry1 argillite1 and granite1 alternating with one another1 means only to affirm that all these stones are found in the ,grampians1 he is certainly in the right1 and the catalogue might easily be enlarged2 but1 if he either means to say1 that these are nearly in equal abundance1 or that the granite is commonly found in strata alternating with other strata1 ,i must say1 that these are propositions quite contrary to any thing ,i have ever seen or heard of those mountains4 ,but it is probable that this is not meant1 and that the fault lies in understanding the expressions much too literally4 ,mr ,kirwan accuses ,dr ,hutton of not knowing where to look for the granite2 not aware of how much1 notwithstanding any error committed in the present estimate1 he was skilled in the art of mineralogical observation2 an art1 which those who have not practised do not always know how to appreciate4 ,but1 however imperfect ,mr ,kirwan's knowledge of this subject has been1 he has here had the good fortune to correct a mineralogist of very superior information4 ,the mere disposition to oppose is not always without its use3 no man is in every thing free from error1 and1 to controvert indiscriminately all the opinions of any individual1 is an infallible secret for being sometimes in the right4 ,,note ,,xvi4 #ajj4 ,rivers and ,lakes4 #cae4 ,rivers are the causes of waste most visible to us1 and most obviously capable of producing great effects4 ,it is not1 however1 in the greatest rivers1 that the power to change and wear the surface of the land is most clearly seen4 ,it is at the heads of rivers1 and in the feeders of the larger streams1 where they descend over the most rapid slope1 and are most subject to irregular or temporary increase and diminution1 that the causes which tend to preserve1 and those that tend to change the form of the earth's surface1 are farthest from balancing one another1 and where1 after every season1 almost after every flood1 we perceive some change produced1 for which no compensation can be made1 and something removed which is never to be replaced4 ,when we trace up rivers and their branches toward their source1 we come at last to rivulets1 that run only in time of rain1 and that are dry1 at other seasons4 ,it is there1 says ,dr ,hutton1 that ,i would wish to carry my reader1 that he may be convinced1 by his own observation1 of this great2 fact1 that the rivers have1 in general1 hollowed out their valleys4 ,the changes of the valley of the main river are but slow2 the plain indeed is wasted in one place1 but is repaired in another1 and we do not perceive the place from whence the repairing matter has proceeded4 ,that which the spectator sees here1 does not therefore immediately suggest to him what has been the state of things before the valley was hollowed out4 ,but it is otherwise in the valley of the rivulet2 no person can examine it without seeing1 that the rivulet carries away matter which cannot be repaired1 except by wearing away some part of the surface of the place upon which the rain that forms the stream is gathered4 ,the remains of a former state are here visible2 and we can1 without any long chain of reasoning1 compare what has been with what is at the present moment4 ,it requires but little study to replace the parts removed1 and to see nature at work1 resolving the most hard and solid masses1 by the continued influences of the sun and atmosphere4#afa ,we see the beginning of that long journey1 by which heavy bodies travel from the summit of the land to the bottom of the ocean1 and we remain convinced1 that1 on our continents1 there is no spot on which a river may not formerly have run4#afb ,footnote #afa3 ,theory of the ,earth1 vol4 ii4 #bid4 ,footnote #afb3 ,ibid4 p4 #bif4 #caf4 ,the view thus afforded of the operations1 in their nascent state1 which have shaped out and fashioned the present surface of the land1 is necessary to prepare us for following them to the utmost extent of their effects4 ,from these effects1 the truth of the proposition1 that rivers have cut and formed1 not the beds only1 but the whole of the valleys1 or rather system of valleys1 through which they flow1 is demonstrated on a principle which has a close affinity to that on which chances are usually calculated1 #ii4 ,in order to conceive rightly the course of a great river1 and the communication subsisting between the main trunk and its remotest branches1 let us take the instance of the ,danube and cast our eyes on one of the maps constructed by ,,marsigli1 for illustrating the natural history of that great river4#afc ,when it is considered1 that over all the vast and uneven surface1 which reaches from the ,alps to the ,euxine1 and from the mountains of ,crapack to those of ,hmus1 a regular communication is kept up between every point and the line of greatest depression1 in which the river flows1 no one can hesitate to acknowledge1 that it is the agency of the waters alone which has opened them a free passage through all the intricacies of this amazing labyrinth4 ,in effect1 suppose this communication to be interrupted1 and that some sudden operation of nature were to erect a barrier of mountains to oppose the ,theise or the ,drave1 as they rolled their waters to the ,danube4 ,from this what could possibly result1 but the damming up of those rivers till their waters were deep1 or high enough to find a vent1 either under the bases or over the tops of the opposing ridge4 ,thus there would be formed immense lakes and immense cataracts1 which1 by filling up what was too low1 and cutting down what was too high1 would in time restore such a uniform declivity of surface as had before prevailed4 ,just so in the times that are past1 whatever may have been the irregularities of the surface at its first emerging from the sea1 or whatever irregularities may have been produced in it by subsequent convulsions1 the slow action of the streams would not fail in time to create or renew a system of valleys communicating with one another1 like that which we at present behold4 ,water1 in all circumstances1 would find its way to the lowest point2 though1 where the surface was quite irregular1 it would not do so till after being dammed up in a thousand lakes1 or dashed in cataracts over a thousand precipices4 ,where neither of these is the case2 and where the lake and the cataract are comparatively rare phenomena2 there we perceive that constitution of a surface1 which water alone1 of all physical agents1 has a tendency to produce2 and we must conclude1 that the probability of such a constitution having arisen from another cause1 is1 to the probability of its having arisen from the running of water1 in such a proportion as unity bears to a number infinitely great4 ,footnote #afc3 ,histoire du ,danube1 tom4 i4 tab4 #cd4 #cag4 ,the courses of many rivers retain marks that they once consisted of a series of lakes1 which have been converted into dry ground1 by the twofold operation of filling up the bottoms1 and deepening the outlets4 ,this happens1 especially1 when successive terraces of gravelly and flat land are found on the banks of a river1 #ajj4 ,such platforms1 or haughs as they are called in this country1 are always proofs of the waste and detritus produced by the river1 and of the different levels on which it has run2 but they sometimes lead us farther1 and make it certain1 that the great mass of gravel which forms the successive terraces on each side of the river1 was deposited in the basin of a lake4 ,if1 from the level of the highest terrace1 down to the present bed of the river1 all is alluvial1 and formed of sand and gravel1 it is then evident1 that the space as low as the river now runs must have been once occupied by water2 at the same time1 it is dear1 that water must have stood1 or flowed as high at least1 as the uppermost surface of the meadow4 ,it is impossible to reconcile these two facts1 which are both undeniable1 but by supposing a lake1 or body of stagnant water1 to have here occupied a great hollow1 7which by us must be held as one of the original inequalities of the globe1 because we can trace it no farther back17 and that this hollow1 in the course of ages1 has been filled up by the gravel and alluvial earth brought down by the river1 which is now cutting its channel through materials of its own depositing4 ,there is no great river that does not afford instances of this1 both in the hilly part of its course1 and where it descends first from thence into the plain4 ,were there room here for the minuter details of topographical description1 this might be illustrated by innumerable examples4 #cah4 ,it is said above1 that the water must have run or stood1 in former times1 as low as the present bottom of the river2 but there is often clear evidence1 that it has run or stood much lower1 because the alluvial land reaches far below the present level of the river4 ,this is known to hold in very many instances1 where it has happened that pits have been sunk to considerable depths on the banks of large rivers4 ,by that means1 the depth of the alluvial ground1 under the present bed of the river1 has been discovered to be great2 and from this arises the difficulty1 so generally experienced1 of finding good foundations for bridges that are built over rivers in large valleys1 or open plains1 the ground being composed of travelled materials to an unknown depth1 without any thing like the native or solid strata4 ,in such cases1 it is evident1 that formerly the water must have been much lower1 as well as much higher1 than its present level1 and this is only consistent with the notion1 that the place was once occupied by a deep lake4 #cai4 ,if1 following the light derived from these indications1 we go back to the time when the river ran above the highest of those levels at which it has left any traces of its operations1 we shall see it composed of a series of lakes and cataracts1 from which1 by the filling up of the one1 and the wearing down of the other1 the waters have at length worked out to themselves a quiet and uninterrupted passage to the ocean4 ,we may1 indeed1 on good evidence1 go back still farther than the succession of such meadows or terraces1 as are above mentioned1 will carry us1 and may consider the whole valley1 or trough of the river1 as produced by its own operations4 ,the original inequalities of the surface1 and the disposition of the strata1 must no doubt have determined the water courses at first2 but this does not hinder us from considering the rivers as having modified and changed those inequalities1 and as the proximate causes of the shape and configuration which the surface has now assumed4 #cbj4 ,from this gradual change of lakes into rivers1 it follows1 that a lake is but a temporary and accidental condition of a river1 which is every day approaching to its termination2 and the truth of this is attested1 not only by the lakes that have existed1 but also by those that continue to exist4 ,where any considerable stream enters a lake1 a flat meadow is usually observed increasing from year to year4 ,the soil of this meadow is disposed in horizontal strata3 the meadow is terminated by a marsh2 which marsh is acquiring solidity1 and is soon to be converted into a meadow1 as the meadow will be into an arable field4 ,all this while the sediment of the river makes its way slowly into the lake1 forming a mound or bank under the surface of the water1 with a pretty rapid slope toward the lake4 ,this mound increases by the addition of new earth1 sand1 and gravel1 poured in over the slope2 and thus the progress of filling up continually advances4 #cba4 ,in small lakes1 this progress may easily be traced2 and will be found singularly conspicuous in that beautiful assemblage of lakes1 which so highly adorns the mountain scenery of ,westmoreland and ,cumberland4 ,among these a great number of instances appear1 in which lakes are either partially filled up1 or have entirely disappeared4 ,in the ,lake of ,keswick1 we not only discover the marks of filling up at the upper end1 which extend far into ,borrowdale1 from which valley a small river flows into the lake2 but we have the clearest proof1 that this lake was once united to that of ,bassenthwaite1 and occupied the whole valley from ,borrowdale to ,ouse-,bridge4 ,these two lakes are at present joined only by a stream1 which runs from the former into the latter1 and their continuity is interrupted by a considerable piece of alluvial land1 composed of beds of earth and gravel1 without rock1 or any appearance of the native strata4 ,this separation1 therefore1 seems no other than a bar1 formed by the influx of two rivers1 that enter the valley here from opposite sides1 the ,greata from the east1 and ,newland's water from the west4 ,the surface of this meadow is at present twelve or fifteen feet at least above the level of either lake and a quantity of water of that depth must therefore have been drawn off by the deepening of the issue at ,ouse-,bridge1 through which the water of both lakes passes1 in its way to the ocean4 ,many more examples1 similar to this1 may be collected from the same lakes2 there are indeed few places from which1 in this branch of geology1 more information may be collected4 #cbb4 ,the larger lakes exemplify the same progress4 ,where the ,rhone enters the ,lake of ,geneva1 the beach has been observed to receive an annual increase2 and the ,portus ,valesi1 now ,port ,valais1 which is at present half a league from the lake1 was formerly close upon its bank4 ,indeed1 the sediments of the ,rhone appear clearly to have formed the valley through which it runs1 to a distance of about three leagues at least from the place where the river now discharges itself into the lake4 ,the ground there is perfectly horizontal1 composed of sand and mud1 little raised above the level of the river1 and full of marshes4 ,the deposition made by the ,rhone after it enters the lake1 is visible to the eye2 and may be seen falling down in clouds to the bottom4 ,the great lakes of ,north ,america are undergoing the same changes1 and1 it would seem1 even with more rapidity4 ,as the rivers1 however1 which supply these vast reservoirs1 are none of them very great1 the filling up is much less remarkable than the draining off of the water1 by the deepening of the outlet4 ,an intelligent traveller has remarked1 that in ,lake ,superior itself the diminution of the waters is apparent1 and that marks can be discovered on the rocks1 of the surface having been six feet higher than it is at present4 ,in the smaller lakes this diminution is still more evident4#afd ,in some of those far inland1 the ground all round appeared to the same traveller to be the deposit from the rivers1 of which the lakes themselves may be considered as a mere expansion4#afe ,footnote #afd3 ,mackenzie's ,voyages through the ,continent of ,north ,america to the ,frozen and ,pacific ,oceans1 p4 xlii4 and xxxvi4 ,footnote #afe3 ,ibid4 p4 #abb4 #cbc4 ,in order to give uniform declivities to the rivers1 the lakes must not only be filled up or drained1 but the cataract1 wherever there is one1 must be worn away4 ,the latter is an operation in all cases visible4 ,the stream1 as it precipitates itself over the rocks1 hurries along with it1 not only sand and gravel1 but occasionally large stones1 which grind and wear down the rock with a force proportioned to their magnitude and acceleration4 ,the smooth surface of the rocks in all waterfalls1 their rounded surface1 and curious excavations1 are the most satisfactory proofs of the constant attrition which they endure2 and1 where the rocks are deeply intersected1 these marks often reach to a great height above the level on which the water now flows4 ,the phenomena1 in such instances1 are among the arguments best calculated to remove all incredulity respecting the waste which rivers have produced1 and are continuing to produce4 ,they suffer no doubt to remain1 that the height and asperity of every waterfall are continually diminishing2 that innumerable cataracts are entirely obliterated2 that those which remain are verging toward the same end1 and that the ,falls of ,montmorenci and ,niagara must ultimately disappear4 #cbd4 ,though there can be no doubt of the justness of the preceding conclusions1 when applied to lakes in general1 some apparent exceptions occur1 in which the progress of draining and filling up seems to have been suspended1 or even to have gone in a contrary direction4 ,these exceptions consist of the lakes which appear to have received a greater quantity of materials than was sufficient to have filled them up4 ,such1 for example1 is the ,lake of ,geneva1 which receives the ,rhone descending from the ,valais1 one of the deepest and longest valleys on the surface of the earth4 ,now1 if this valley1 or even a large proportion of it1 had been excavated by the ,rhone itself1 as our theory leads us to suppose1 the lake ought to have been entirely filled up1 because the materials brought down by the river seem to be much greater than the lake1 on any reasonable supposition concerning its original magnitude1 can possibly have received4 ,what1 then1 it may be said1 has become of all that the ,rhone has brought down and deposited in it8 ,the lake1 at this moment1 retains1 in some places1 the depth of more than #ajjj feet2 and yet1 of all that the ,rhone carries into it1 nothing but the pure water issues4 ,if it has been continuing to diminish1 both in superficial extent and in depth1 from the time when the ,rhone began to run into it1 what must have been its original dimensions8 ,i cannot pretend to remove entirely the difficulty which is here stated2 yet ,i think the following remarks may go some length in doing so4 #cbe4 ,it is certain1 that from the present state of the ,lake of ,geneva1 and of the ground round it1 we can hardly draw any inference as to its original dimensions4 ,saussure has traced1 with his usual skill1 the marks of the course of the ,rhone1 on a level greatly above the present2 and1 by observations on the side of ,mont ,saleve1 has found proofs of the running of water1 at least #bjj toises above the present superficies of the lake4 ,but1 if ever the superficies of the lake stood at this height1 or at this height nearly1 though we can conjecture but little concerning the state of the adjacent country1 which no doubt was also on a higher level1 the lake may very well be supposed to have been of far greater dimensions than it is now4 ,it may have occupied the whole space from ,jura to ,saleve1 and included the ,lake of ,neufchtel2 so that it may have been of magnitude sufficient to receive the spoils of the ,valais1 which1 as the surface of its waters lowered1 may have been washed away and carried down to the sea4 ,thus it may have afforded a temporary receptacle for the debris of the ,alps1 and may have served for an entrepot1 as it were1 where those debris were deposited1 before they were carried to the place of their ultimate destination4 #cbf4 ,but the great depth which the lake has at present1 still remains to be explained1 because no mud or gravel could be carried beyond the gulf1 of a thousand feet deep1 which was here ready to receive it4 ,the reality of this difficulty must be acknowledged2 and some cause seems to act1 if not in the generation1 yet certainly in the preservation of lakes1 with which we are but little acquainted ,we can indeed imagine some causes of that kind to occur in the course of the degradation of the land1 which may produce new lakes1 or increase the dimensions of the old4 ,the wearing away of a stratum1 or body of strata1 may lay bare1 and render accessible to the water1 some beds of mineral substances soluble in that fluid4 ,the district1 for instance1 in ,cheshire1 which contains rock-salt1 extends over a tract of fourteen or fifteen miles1 and is covered by a thick stratum of clay1 more or less indurated1 which defends the salt from the water at the surface1 and preserves the whole mass in a state of dryness4 ,should this covering be broke open by any natural convulsion1 or should it be worn away1 as it must be in the progress of the general detritus1 the water would gain admission to the saline strata1 would gradually dissolve them1 and form of course a very deep and extensive lake1 where all was before dry land4 ,this event is not only possible1 but it should seem1 that in the course of things it must necessarily happen4 #cbg4 ,something of this kind may have taken place in the track of the ,rhone1 and may have produced the ,leman ,lake4 ,it is not impossible1 that1 at a very remote period1 the ,rhone descended from the ,alps without forming any lake1 or at least any lake of which the remains are now existing2 and this supposition1 which is more probable than that of #cbe1 we shall soon find to be conformable to appearances of another kind4 ,the river may have wore away the secondary limestone strata over which it took its course after it left the schistus of the mountains2 and1 in doing so1 may have reached some stratum of a saline nature1 and this being washed out1 may have left behind it a lake1 which is but modern compared with many of the revolutions that have happened on the surface of the earth4#aff ,footnote #aff3 ,there are salt springs at ,bex1 near ,aigle1 about ten miles from the head of the lake3 saline strata1 therefore1 are probably at no great distance4 ,this explanation is no doubt hypothetical2 but it is proposed in one of those cases1 in which hypothetical reasonings are warranted by the strictest rules of philosophical investigation4 ,it is proposed in a case1 where the causes visible to man seem inadequate to the effect1 and where we must therefore have recourse to an agent that is invisible4 ,if the operations ascribed to this agent are conformable to the analogy of nature1 it is all that can in reason be required4 #cbh4 ,another circumstance may also influence the generation and preservation of lakes2 but it is also one with which we are but little acquainted4 ,the strata1 and indeed the whole body of mineral substances which forms the basis of our land1 have been raised up from the bottom of the sea1 by a progress that should seem in general to have been gradual and slow4 ,appearances1 however1 are not wanting1 which show1 that this progress is not uniform2 and that both rising and sinking in the surface of the land1 or in the rocks which are the base of it1 have happened within a period of time1 which is by no means of great extent4 ,in this progress1 the elevations and depressions may not be the same for every spot4 ,they may be partial1 and one part of a stratum1 or body of strata1 may rise to a greater height1 or be more depressed1 than another4 ,it is not impossible1 that this process may affect the depth of lakes1 and change the relative level of their sides and bottom4 #cbi4 ,all lakes1 however1 do not involve the difficulty which the preceding conjectures are intended to remove4 ,the great lakes of ,north ,america do not1 for instance1 receive their supply from very large rivers4 ,of course1 it is not from a tract great in comparison of themselves1 that the waste and detritus is brought down into them2 and it seems not at all wonderful1 that1 without being filled up1 they have been able to receive it4 ,the same1 in a degree at least1 is true of many other lakes4 ,it should also be considered1 that we may err greatly in the estimate we make of the materials actually carried down and deposited in any lake4 ,to judge of their entire amount1 we should know the original form of the inequalities on the earth's surface2 of the quantity of depression which existed1 independently of the rivers2 and though1 in general1 these original inequalities may be overlooked1 and the present considered as made by the running of water1 yet1 in particular instances1 this may be far from true4 ,the ,valais1 for example1 which we consider as the work of the ,rhone1 may1 when the ,alps rose out of the sea1 have included many depressions of the surface1 which the river joined together1 and1 from being a series of lakes1 formed into one great valley4 99 99 99 99 99 #ccj4 ,the mouths by which rivers on bold rocky coasts discharge their waters into the sea1 afford a very striking confirmation of the conclusions concerning the general system of waste and degradation which have been drawn above4 ,at these mouths we usually see1 not only the bed of the river1 but frequently a considerable valley1 cut out of the solid rock1 while that rock preserves its elevation1 and its precipitous aspect1 wherever it is not intersected by a run of water4 ,no convulsion that can have torn asunder the rocks2 no breach that can have been made in them1 antecedent to the running of the waters1 will account for the circumstance of every river finding a corresponding opening1 by which it makes its way to the sea2 for that opening being so nearly proportional to the magnitude of the river1 and for such breaches never occurring but where streams of water are found4 #cca4 ,the actual survey of any bold and rocky coast1 will make this clearer than any general statement can possibly do4 ,let us take1 for an example1 the coast of the ,british ,channel1 from ,torbay to the ,land's ,end1 which is faced by a continued rampart of high cliffs1 formed of much indurated and primeval rock4 ,if we consider the breaches in this rampart1 at the mouths of the ,dart1 of the ,plym and ,tamer1 of the river at ,fowey1 of the ,fal1 the ,hel1 c4 it will appear perfectly clear1 that they have been produced by their respective streams4 ,where there is no stream1 there is no breach in the rock1 no softening in the bold and stern aspect which this shore every where presents to the ocean4 ,if we look at the smaller streams1 we find them working their way through the cliffs at the present moment2 and we see the steps by which the larger valleys of the ,dart and the ,tamer have been cut down to the level of the sea4 ,if we would have still clearer evidence1 that no breaches made antecedently to the running of the rivers have opened a way for them1 we need only look to the opposite side1 or northern shore1 of the same promontory1 where we also find a series of outlets1 all originating in the ridge of the country1 and becoming deeper as they approach the sea1 but altogether unconnected with the openings on the south side2 and this could hardly have been the case1 had they been the effects of previous concussions1 or of any peculiarity in the original structure of the rocks4 #ccb4 ,in contemplating such coasts as these1 when we go back to the time when the rivers ran upon a level as high as the highest of the cliffs on the sea shore1 we must suppose1 that the land then extended many miles farther into what is now occupied by the sea4 ,when at ,plymouth1 for instance1 the ,tamer and the ,plym flowed on the level of ,mount ,edgecombe or of ,staten ,heights1 if the rivers ran with a moderate declivity into the sea1 the coast must have advanced many miles beyond its present line4 ,thus the land1 when higher1 was also more extended1 and the limits of our island in that ancient state1 were doubtless very different from these by which it is at present circumscribed4 ,if with the same views we consider any other of the bold coasts which the map of the world presents us with1 we shall quickly remark1 that wherever a deep intersection of the sea is made into the land1 as on the western shores of our own island1 or on those of ,norway1 a river runs in at the head of it1 and points out by what means such inlets are formed1 viz4 by the united powers of the sea and of the land1 the waters of the latter having opened the way by which those of the former have penetrated so far into the country4 #ccc4 ,it is not meant assuredly to deny the irregularities of the sea coast1 as it may have originally existed2 these irregularities no doubt determined the initial operations of that waste and decay1 by which1 in process of time1 they were themselves entirely effaced4 ,the line of our coasts may be compared to one of those curves1 which are sometimes treated of in the higher geometry1 where the ordinates are functions1 not only of1 their absciss1 but also of the time elapsed since a certain epocha4 ,the form of the curve at that epocha1 or when the time began to flow1 corresponds to the original form of the sea coast1 on its emerging from the ocean1 and before the powers of wasting and decay had begun to act upon it4 ,to speak strictly1 the original figure1 in both cases1 influences all the subsequent2 but the farther removed from it in point of time1 the less is that influence2 so that1 in physical questions1 and for the purpose of such approximations as suit the imperfection of our knowledge1 the consideration of the original figure may be wholly left out4 ,,note ,,xvii4 #aje4 ,remains of ,decomposed ,rocks4 #ccd4 ,,the plain of ,crau was the ,campus ,lapideus of the ancients2 and1 as mythology always seeks to connect itself with the extraordinary facts in natural history1 it was said to be the spot where ,hercules1 fighting with the sons of ,neptune1 and being in want of weapons1 was supplied from heaven by a shower of stones3 hence it was called ,campus ,herculeus4 ,this plain is on the east side of the ,rhone1 between ,salon and ,aries3 it is of a triangular form1 about twenty square leagues in extent1 and is covered almost entirely with quartzy gravel4 ,this immense collection of gravel has been supposed by some to have been brought down by the ,durance from the ,alps of ,dauphine2 by others it has been ascribed to the ,rhone2 and by many to the sea1 as being a work too great for any river4 ,the explanation mentioned above1 #aje1 namely1 that the loose gravel on the plain arises from the decomposition of a great stratum of pudding-stone1 which is the basis of the whole1 is the opinion of ,saussure1 and is founded on his own observations4#afg ,footnote #afg3 ,see ,voyages aux ,alpes1 tom4 iii4 #aeib et #aeig4 ,see also on this subject a ,memoir by ,lamanon1 ,journal de ,physique1 tom4 xxii4 p4 #dgg2 and another by ,m4 ,de ,servieres1 ibid4 p4 #bgj4 #cce4 ,the theories that have been contrived for explaining the phenomena of the plain of ,crau1 afford an instance of the necessity of generalizing our observations before we can explain a particular appearance3 in other words1 they prove the truth of ,lord ,bacon's maxim1 ,that the explanation of a phenomenon should not be sought for from the study of that phenomenon alone1 but from the comparison of it with others4 ,one of the theories of this plain is1 that the breccia1 which is the base of it1 is formed from the consolidation of the loose gravel of the plain1 by water percolating through it1 and carrying some cementing substance along with it1 or some lapidific juice1 as it is called4 ,and indeed1 whether the gravel is formed from the breccia1 or the breccia from the gravel1 is a question which probably could never be resolved by the mere examination of the plain itself4 ,but the question is very soon decided1 when we compare what is observed here with other appearances in the natural history of the earth's surface1 and consider how much more frequent the decomposition of solids is1 than their reconsolidation1 in any place above the level of the sea4 #ccf4 ,the argument for the decomposition of stony substances which is afforded by the state of this singular plain1 may be confirmed by the appearances observed in many extensive tracts of land all over the world1 and especially in some parts of ,great ,britain4 ,the road to ,exeter from ,taunton ,dean1 between the latter and ,honiton1 passes over a large heath or down1 considerably elevated above the plain of ,taunton4 ,the rock which is the base of this heath1 as far as can be discovered1 is limestone1 and over the surface of it large flints1 in the form of gravel1 are very thickly spread4 ,there is no higher ground in the neighbourhood from which this gravel can be supposed to have come1 nor any stream that can have carried it1 so that no explanation of it remains1 but that it is formed of the flints contained in beds of limestone1 which are now worn away4 ,the flints on the heath are precisely of the kind found in limestone2 many of them are not much worn1 and cannot have travelled far from the rock in which they were originally contained4 ,it seems certain1 therefore1 that they are the debris of limestone strata1 now entirely decomposed1 that once lay above the strata which at present form the base of this elevated plain1 and probably covered them to a considerable height4 ,this explanation carries the greater probability with it1 that any other way of accounting for the fact in question1 as the travelling of the gravel from higher grounds1 or the immersion of the surface under the sea1 will imply changes in the face of the country1 incomparably greater than are here supposed4 ,our hypothesis seems to give the minimum of all the kinds of change that can possibly account for the phenomenon4 #ccg4 ,the same remarks may be made on the high plain of ,blackdown1 which the road passes over in going from ,exeter to the westward4 ,the flints there are disseminated over the surface as thickly as in the other instance1 and can be explained only on the same supposition4 ,again1 in the interior of ,england1 beginning from about ,worcester and ,birmingham1 and proceeding north-east through ,warwickshire1 ,leicestershire1 ,nottinghamshire1 as far as the south of ,yorkshire1 a particular species of highly indurated gravel1 formed of granulated quartz1 is found every where in great abundance4 ,this same gravel extends to the west and north-west1 as far as ,ashburn in ,derbyshire1 and perhaps still farther to the north4 ,the quantity of it about ,birmingham is very remarkable1 as well as in many other places2 and the phenomenon is the more surprising1 that no rock of the same sort is seen in its native place4 ,it is such gravel as might be expected in a mountainous country1 in ,scotland1 for instance1 or in ,switzerland1 but not at all in the fertile and secondary plains of ,england4 ,this enigma is explained1 however1 when it is observed1 that the basis of the whole tract just described is a red sandstone1 often containing in it a hard quartzy gravel1 perfectly similar to that which has just been mentioned4 ,from the dissolution of beds of this sandstone1 which formerly covered the present1 there can be no doubt that this gravel is derived4 ,but1 as the gravel is in general thinly dispersed through the sandstone1 and abounds only in some of its layers1 it should therefore seem1 that a vast body of strata must have been worn away and decomposed1 before such quantities of gravel as now exist in the soil could have been let loose4 #cch4 ,i have said1 that a rock capable of affording such gravel as this1 is not to be found in the tract of country just mentioned4 ,this however1 is not strictly true2 for in ,worcestershire1 between ,bromesgrove and ,birmingham1 about seven miles from the latter1 a rock is found consisting of indurated strata1 greatly elevated1 and without doubt primitive1 from the detritus of which such gravel as we are now speaking of might be produced4 ,these strata seem to rise up from under the secondary1 where they are intersected by the road2 and1 for as much as appears1 are not of great thickness1 so that they cannot have afforded the materials of this gravel directly1 though they may have done so indirectly1 or through the medium of the red sandstone2 that is to say1 a primary rock of which they are the remains1 may have afforded materials for the gravel in the sandstone2 and this sandstone may in its turn have afforded the materials of the present soil1 and particularly the gravel contained in it4 #cci4 ,pudding-stones being very liable to decomposition1 have probably1 in most countries1 afforded large proportion of the loose gravel now found in the soil ,the mountains1 or at least hills1 of this rock1 which are found in many places1 prove the great extent of such decomposition4 ,mount ,rigi1 for instance1 on the side of the ,lake of ,lucerne1 is entirely of pudding-stone1 and is #gdb toises in height1 measured from the level of the lake4 ,by the descriptions given of it1 as well as of other hills of the same kind in ,switzerland1 we may1 without due attention1 be led to suppose that they are entirely formed of loose gravel4 ,even ,m4 ,saussure's description is chargeable with this fault1 though1 when attended to1 it will be found to contain a sufficient proof1 that this hill is composed of real pudding-stone4#afh ,the nature of the thing also1 would be sufficient to convince us1 that a hill1 more than #djjj feet in height1 could not consist of loose and unconsolidated materials4 ,if1 then1 we regard ,mount ,rigi as the remains of a body of pudding-stone strata1 we must conclude1 that these strata were originally more extensive1 and the adjacent valleys and plains will serve1 in some degree1 to measure the quantity of them which time has destroyed4 ,footnote #afh3 ,voyages aux ,alpes1 tom4 iv4 #aida4 #cdj4 ,if the theory of unstratified mountains1 namely those of whinstone1 porphyry1 and granite1 be admitted as laid down above1 it will furnish a measure of the destruction which has taken place in the stratified rocks1 and of the vast depredations which have been made upon them since they were raised up from the bottom of the sea4 ,like every other measure1 however1 of wasting1 by a thing that is itself subject to waste1 it can only give a minimum1 or a limit which the quantity wasted must necessarily exceed4 ,the abrupt face of a whinstone rock must be understood as an evidence1 that some body of strata which supported it when fluid1 remained in contact with it1 when it was become solid2 and if this part of the mould in which the whinstone was cast1 has disappeared1 it must generally be ascribed to the operation of waste and decomposition4 ,such a face1 for instance1 as that which ,salisbury ,craig presents to the west1 viz4 a perpendicular wall of whinstone1 about ninety feet high1 raised on a body of sandstone strata of the height of about #cjj feet1 can have been produced only by having been abutted against some stratified rock1 equally abrupt1 and of the same elevation with itself4 ,of this rock no part remains4 ,the basaltic rock of ,edinburgh ,castle is nearly in the same state4 ,its perpendicular sides on the south1 west1 and north1 are now disengaged from the strata by which they were once encompassed4 #cda4 ,the granite mountains also1 where they are quite unstratified1 give rise to the same conclusion4 ,those central chains which we find in so many instances towering above the schistus which cover their sides1 have probably been once completely enveloped by the latter2 and1 on this supposition1 an estimate may sometimes be formed of the original height of such mountains4 ,in these estimations1 however1 some uncertainty must arise1 from our being unable to distinguish between the effects which are to be ascribed to the fracture and dislocation that took place when the compound body of stratified and unstratified rocks was raised up from the bottom of the sea1 and the effects produced by the subsequent waste and decomposition at the surface4 ,in this1 as in many other instances1 we are not always able to separate between the original inequalities of the surface1 and those which wearing has produced4 #cdb4 ,it would be important to ascertain the rate at which the elevation of mountains decreases1 and this is what we may perhaps expect to be accomplished1 by the progress of geological science1 and the multiplying of accurate observations4 ,it has been supposed1 that the ,pyrenees diminish about ten inches in a century2 but what confidence is to be put in this estimate1 ,i am unable to determine4#afi ,footnote #afi3 ,essai sur la ,mineralogie des ,pyrenes1 p4 #hg4 ,a very unequivocal mark of the degradation of mountains is often to be met with in the heaps of loose stones found on their tops4 ,these stones1 it is obvious1 cannot have come from any other place by natural means1 and they are accordingly always sharp and angular1 and have none of the characters of transported rocks4 ,they are said sometimes to have been brought by men's hands2 but this is highly improbable1 their quantity is often so considerable1 and the difficulty of transportation so great4 ,where any purpose was to be served by heaping them together1 men have availed themselves of the stones that they found ready prepared on the summit1 and have constructed from them cairns1 which have served as signals1 useful in their pastoral1 and sometimes in their military occupations4 ,,note ,,xviii4 #aab4 ,transportation of ,stones1 c4 #cdc4 ,,nature supplies the means of tracing with considerable certainty the migration of fossil bodies on the surface of the earth1 as only the more indurated stones1 and those most strongly characterized1 can endure the accidents that must befal them in travelling to a distance from their native place4 ,it is a fact very generally observed1 that where the valleys among primitive mountains open into huge plains1 the gravel of those plains consists1 of stones1 evidently derived from the mountains4 ,the nearer that any spot is to the mountains1 the larger are the gravel stones1 and the less rounded is their figure2 and1 as the distance increases1 this gravel1 which often forms a stratum nearly level1 is covered with a thicker bed of earth or vegetable soil4 ,this progression has particularly been observed in the valleys of ,pimont and the plains of ,lombardy1 where a bed of gravel forms the basis of the soil1 from the foot of the ,alps to the shores of the ,hadriatic4#agj ,we may collect from ,,guettard1 that a similar gradation is found in the gravel and earth which cover the great plain of ,poland1 from ,mount ,krapack to the ,baltic4#aga ,the reason of this gradation is evident2 the farther the stones have travelled1 and the more rubbing they have endured1 the smaller they grow1 the more regular is the figure they assume1 and the greater the quantity of that finer detritus which constitutes the soil4 ,the washing of the rains and rivers is here obvious2 and each of the three quantities just mentioned1 if not directly proportional to the distance which the stones have migrated from their native place1 may be said1 in the language of geometry1 to be at least proportional to a certain function of that distance4 ,footnote #agj3 ,voyages aux ,alpes1 tom4 iii4 #acae4 ,footnote #aga3 ,mm4 ,acad4 des ,sciences1 #agfb1 p4 #bcd1 #bic1 c4 #cdd4 ,the immense quantity of cailloux rouls1 or rounded gravel1 collected in the immediate vicinity of mountainous tracts1 has led some geologists to suppose the existence of ancient currents1 which descended from the mountains1 in a quantity1 and with a momentum1 of which there is no example in the present state of the world4 ,thus ,saussure imagines1 that the hill of ,supergue1 near ,turin1 which is formed of gravel1 can only be explained by supposing such currents as are just mentioned1 or what he terms a debacle1 to have taken place at some former period4#agb ,if1 however1 we ascribe to the mountains a magnitude and elevation vastly greater than that which they now possess2 if we regard the valleys between them as cut out by the rivers and torrents from an immense rampart of solid rock1 neither materials sufficiently great1 nor agents sufficiently powerful1 will appear to be wanting1 for collecting bodies of gravel and other loose materials1 equal to any that are found on the surface of the earth4 ,the necessity of introducing a debacle1 or any other unknown agent1 to account for the transportation of fossils1 seems to arise from underrating the effects of action long continued1 and not limited by such short periods as circumscribe the works1 and even the observations1 of men4 ,footnote #agb3 ,voyages aux ,alpes1 tom4 iii4 #acjc4 #cde4 ,the supply of gravel and cailloux rouls1 for the plains extended at the feet of primitive mountains1 is doubtless in many cases much increased by the pudding-stone1 interposed between the secondary and the primary strata4 ,the beds of pudding-stone contain gravel already formed on the shores of continents1 that ceased to exist before the present were produced2 and the cement of this gravel1 yielding easily to the weather1 allows the stones included in it to be washed down by the torrents1 and scattered over the plains4 ,i know not if the hill of ,supergue above mentioned1 is not in reality a mass of the pudding-stone which forms the border of the ,alps1 and of which the materials have suffered no transportation since the time of their last consolidation4 ,this at least is certain1 that ,saussure1 notwithstanding his accuracy1 has sometimes confounded the loose gravel on the surface with that which is consolidated into rock2 an inaccuracy which is to be charged1 as ,i have elsewhere observed1 rather against his system than himself4 #cdf4 ,the loose stones found on the sides of hills1 and the bottoms of valleys1 when traced back to their original place1 point out with demonstrative evidence the great changes which have happened since the commencement of their journey2 and in particular serve to show1 that many valleys which now deeply intersect the surface1 had not begun to be cut out when these stones were first detached from their native rocks4 ,we know1 for instance1 that stones under the influence of such forces as we are now considering1 cannot have first descended from one ridge1 and then ascended on the side of an opposite ridge4 ,but the granite of ,mont ,blanc has been found1 as mentioned above1 on the sides of ,jura1 and even on the side of it farthest from the ,alps4 ,now1 in the present state of the earth's surface1 between the central chain of the ,alps1 from which these pieces of granite must have come1 and the ridge of ,mont ,jura1 besides many smaller valleys1 there is the great valley of the ,rhone1 from the bottom of which1 to the place where they now lie1 is a height of not less than #cjjj feet4 ,stones could not1 by any force that we know of1 be made to ascend over this height4 ,we must therefore suppose1 that when they travelled from ,mont ,blanc to ,jura1 this deep valley did not exist1 but that such an uniform declivity1 as water can run on with rapidity1 extended from the one summit to the other4 ,this supposition accords well with what has been already said concerning the recent formation of the ,leman ,lake1 and of the present valley of the ,rhone4 #cdg4 ,we can derive1 in a matter of this sort1 but little and from calculation2 yet we may discover by it1 whether our hypothesis transgresses materially against the laws of probability1 and is inconsistent with physical principles already established4 ,the horizontal distance from ,mont ,jura to the granite mountains1 at the head of the ,arve1 may be accounted fifty geographic miles4 ,though we suppose ,mont ,blanc1 and the rest of those mountains1 to have been originally much higher than they are at present1 the ridge of ,jura must have been so likewise2 and though probably not by an equal quantity1 yet it is the fairest way to suppose the difference of their height to have been nearly the same in former ages that it is at present1 and it may therefore be taken at #aj1jjj feet4 ,the declivity of a plane from the top of ,mont ,jura to the top of ,mont ,blanc1 would therefore be about one mile and three quarters in fifty1 or one foot in thirty2 an inclination much greater than is necessary for water to run on1 even with extreme rapidity1 and more than sufficient to enable a river or a torrent to carry with it stones or fragments of rock1 almost to any distance4 ,saussure1 in relating the fact that pieces of granite are found among the high passes near the summits of ,mont ,jura1 alleges1 that they are only found in spots from which the central chain of the ,alps may be seen4 ,but it should seem that this coincidence is accidental1 because1 from whatever cause the transportation of these blocks has proceeded1 the form of the mountains1 especially of ,mont ,jura1 must be too much changed to admit of the supposition1 that the places of it from which ,mont ,blanc is now visible1 are the same from which that mountain was visible when these stones were transported hither4 ,it may be1 however1 that the passes which now exist in ,mont ,jura are the remains of valleys or beds of torrents1 which once flowed westward from the ,alps2 and it is natural1 that the fragments from the latter mountains should be found in the neighbourhood of those ancient water-tracks4 #cdh4 ,saussure observed in another part of the ,alps1 that where the ,drance descends from the sides of ,mont ,velan and the ,great ,st ,bernard1 to join the ,rhone in the ,valais1 the valley it runs in lies between mountains of primary schistus1 in which no granite appears1 and yet that the bottom of this valley1 toward its lower extremity1 is for a considerable way covered with loose blocks of granite4#agc ,his familiar acquaintance with all the rocks of those mountains1 led him immediately to suspect1 that these stones came from the granite chain of ,mont ,blanc1 which is westward of the ,drance1 and considerably higher than the intervening mountains4 ,this conjecture was verified by the observations of one of his friends1 who found the stones in question to agree exactly with a rock at the point of ,ornes1 the nearest part of the granite chain4 ,footnote #agc3 ,voyages aux ,alpes1 tom4 ii4 #ajbb4 ,in the present state of the surface1 however1 the valley of ,orsiere lies between the rocks of ,ornex and the valley of the ,drance1 and would certainly have intercepted the granite blocks in their way from the one of these points to the other1 if it had existed at the time when they were passing over that tract4 ,the valley of ,orsiere1 therefore1 was not formed1 when the torrents1 or the glaciers transported these fragments from their native place4 ,mountainous countries1 when carefully examined1 afford so many facts similar to the preceding1 that we should never have done were we to enumerate all the instances in which they occur4 ,they lead to conclusions of great use1 if we would compare the machinery which nature actually employs in the transportation of rocks1 with the largest fragments of rock which appear to have been removed1 at some former period1 from their native place4 #cdi4 ,for the moving of large masses of rock1 the most powerful engines without doubt which nature employs are the glaciers1 those lakes or rivers of ice which are formed in the highest valleys of the ,alps1 and other mountains of the first order4 ,these great masses are in perpetual motion1 undermined by the influx of heat from the earth1 and impelled down the declivities on which they rest by their own enormous weight1 together with that of the innumerable fragments of rock with which they are loaded4 ,these fragments they gradually transport to their utmost boundaries1 where a formidable wall ascertains the magnitude1 and attests the force1 of the great engine by which it was erected4 ,the immense quantity and size of the rocks thus transported1 have been remarked with astonishment by every observer1#agd and explain sufficiently how fragments of rock may be put in motion1 even where there is but little declivity1 and where the actual surface of the ground is considerably uneven4 ,in this manner1 before the valleys were cut out in the form they now are1 and when the mountains were still more elevated1 huge fragments of rock may have been carried to a great distance2 and it is not wonderful1 if these same masses1 greatly diminished in size1 and reduced to gravel or sand1 have reached the shores1 or even the bottom1 of the ocean4 ,footnote #agd3 ,the stones collected on the ,glacier de ,miage1 when ,saussure visited it1 were in such quantity as to conceal the ice entirely4 ,voyages aux ,alpes1 tom4 ii4 #hed4 #cej4 ,next in force to the glaciers1 the torrents are the most powerful instruments employed in the transportation of stones4 ,these1 when they descend from the sides of mountains1 and even where the declivity of their course is not very great1 produce effects which nothing but direct experience could render credible4 ,the fragments of rock which oppose the torrent1 are rendered specifically lighter by the fluid in which they are immersed1 and lose by that means at least a third part of their weight3 they are1 at the same time1 impelled by a force proportional to the square of the velocity with which the water rushes against them1 and proportional also to the quantity of gravel and stones which it has already put in motion4 ,perhaps1 after taking all these circumstances into computation1 in the midst of a scene perfectly quiet and undisturbed1 a philosopher might remain in doubt as to the power of torrents to move the enormous bodies of rock which are seen in the bottom of the narrow valleys or deep glens of a mountainous country2 but his incredulity1 says an experienced traveller1 will cease altogether1 if he has been surprised by a storm in the midst of some ,alpine region2 if he has seen the number and impetuosity of the cataracts which rushed down the sides of the mountains1 and beheld the ruin which accompanied them2 and if1 when the tempest was passed1 he has viewed those meadows1 which a few hours before were covered with verdure1 now buried under heaps of stones1 or overwhelmed by masses of liquid mud1 and the sides of the mountains cut by deep ravines1 where the track of the smallest rivulet was not before to be discovered4#age ,footnote #age3 ,see an account of a thunder storm near ,bareges1 in the ,essai sur la ,mineralogie des ,pyrenes1 p4 #acd4 ,it is but rarely1 however1 even on occasions like these1 that such vast masses of rock can be seen actually in motion1 as are often found on the surface1 apparently removed to a great distance from their native place4 ,the magnitude of these is so great1 in many instances1 that their transportation cannot be explained without supposing1 that the surface was very different when these transportations took place from what it is at present2 that the elevation of the mountains was greater1 and the ground smoother and more uniform1 at least in some directions4 ,if these suppositions are admitted1 and they are countenanced1 as we have already seen1 by almost every phenomenon in geology1 the difficulties which present themselves here will not appear insurmountable4 #cea4 ,one of the largest blocks of granite that we know of1 is on the east side of the lake of ,geneva1 called ,pierre de ,gout1 about ten feet in height1 with a horizontal section of fifteen by twenty4#agf ,another block not far from it1 and nearly of the same size1 has some remains of schistus attached to it4 ,these stones very much resemble those which have fallen from the ,aiguilles1 in the valley of ,chamouni4 ,the distance from their present situation to those ,aiguilles is about thirty ,english miles1 with many mountains and valleys at present interposed4 ,by whatever means1 therefore1 these blocks were transported1 their motion must have been over a surface of much more uniform declivity than the present4 ,if the surface was without great inequalities1 and its general declivity about one foot in thirty1 as already computed1 the glaciers1 in the first place1 and the torrents afterwards1 may have served for the transportation even of these rocks4 ,footnote #agf3 ,voyages aux ,alpes1 tom4 i4 #cjh4 #ceb4 ,again1 in the narrow vale or glen which separates the ,great from the ,little ,saleve1 the strata are all calcareous1 but a great number of loose blocks of granite and primary schistus are scattered over the surface4 ,a block of the former1 near the lower end of the valley1 is about the size of #abjj cubic feet4 ,two other large blocks of the same kind of stone rest on a base of horizontal limestone1 elevated two or three feet above the rest of the surface4 ,this elevation arises no doubt from the protection which the stones have afforded to the calcareous beds on which they lie1 so that these beds do not wear away so fast as those which are fully exposed to the weather4 ,but it is surely to take a very limited view of the operations on the surface1 to suppose1 with ,saussure1 that the parts of the calcareous rock under these stones has suffered no waste whatsoever1 so that the stones remain now in the identical spot where they were placed by the great debacle which brought them down from the high ,alps4#agg ,for my part1 ,i have no doubt that the ,arve1 which is still at no great distance1 when it ran on a higher level1 and in a line different from the present1 aided by the glaciers and superior elevation of the mountains1 was an engine sufficiently powerful for effecting the transportation of these stones4 ,footnote #agg3 ,ibid4 #bbg4 #cec4 ,these phenomena are not peculiar to the ,alps1 but prevail1 in a greater or less degree1 in the vicinity of all primary or granite mountains4 ,in the island of ,arran1 a fragment of the same kind with that which constitutes the upper part of ,goatfield1 is found on the sea shore1 at least three miles from the nearest granite rock1 and with a bay of the sea intervening4 ,its dimensions are not far from those of the pierre de gout4 ,in some former state of the granitic mountains in that island1 the declivity from the top of ,goatfield may have been very uniform1 and more rapid than it is at present4 #ced4 ,besides glaciers and torrents1 which have no doubt been the principal instruments in producing these changes1 other causes may have occasionally operated4 ,large stones1 when once detached1 and resting on an inclined plane1 from the effects of waste and decomposition1 may advance horizontally1 at the same time that they descend perpendicularly1 and this will happen though they be not urged by any torrent1 or any thing but their own weight2 for the surface of the ground1 as it wastes1 remains higher under the stone1 and for a little way round it1 than at a greater distance1 on account of the protection which it receives from the stone1 as in the instances at ,saleve1 just mentioned4 ,the stone itself also becomes rounded at the bottom2 and thus the surface in contact with the ground is diminished in extent1 and the two surfaces rendered convex towards one another4 ,it must therefore happen1 that the support1 continually weakening1 will at length give way1 and the stone incline or roll toward the lower side1 and may even roll considerably1 if its centre of gravity has been high above its point of support1 and if its surface has had much convexity3 ,thus the horizontal may very far exceed the perpendicular motion2 and1 in the course of ages1 the stone may travel to a great distance4 ,a stone1 however1 which travels in this manner1 must diminish as it proceeds1 and must have been much greater in the beginning than it is at present4 #cee4 ,this kind of motion may be aided by particular circumstances4 ,when a stone rests on an inclined plane1 so as to be in a state not very remote from equilibrium1 if a part be taken away from the upper side1 the equilibrium will be lost1 and the stone will thereby be put in motion4 ,that stones which lie on other stones1 may1 by wearing1 be brought very near an equilibrium1 is proved by what are called rocking-stones1 or in ,cornwall ,logan stones1 which have sometimes been mistaken for works of art2 but are certainly nothing else than stones1 which have been subjected to the universal law of wasting and decay1 in such peculiar circumstances1 as nearly to bring about an equilibrium of that stable kind1 which1 when slightly disturbed1 re-establishes itself4#agh ,the ,logan stone at the ,land's ,end1 is a mass of granite1 weighing more than sixty tons1 resting on a rock of granite1 of considerable height1 and close on the sea shore4 ,the two stones touch but in a small spot1 their surfaces being considerably convex towards one another4 ,the uppermost is so nearly in an equilibrium1 that it can be made to vibrate by the strength of a man1 though to overset it entirely would require a vast force4 ,this arises from the centre of gravity of the stone being somewhat lower than the centre of curvature of that part of it on which it has a tendency to roll2 the consequence of which is1 that any motion impressed on the stone1 forces its centre of gravity to rise1 7though not very considerably17 by which means it returns whenever the force is removed1 and vibrates backward and forward1 till it is reduced to rest4 ,were it required to remove the stone from its place1 it might be most easily done1 by cutting off a part from one side1 or blowing it away by gunpowder2 the stone would then lose its balance1 would tumble from its pedestal1 and might roll to a considerable distance4 ,now1 what art is here supposed to perform1 nature herself in time will probably effect4 ,if the waste on one side of this great mass shall exceed that on the opposite in more than a certain proportion1 and it is not likely that that proportion will be always maintained1 the equilibrium of the ,logan stone will be subverted1 never to return4 ,thus we perceive how motion may be produced by the combined action of the decomposition and gravitation of large masses of rock4 ,footnote #agh3 ,i do not presume so far as to say1 that all rocking-stones are produced by natural means3 ,i have not sufficient information to justify that assertion2 but the great size of that at the ,land's ,end1 its elevated position1 and the approaches toward something of the same kind which are to be seen in other parts of that shore1 prove that it is no work of art4 ,they who ascribe it to the ,druids1 do not consider the rapidity with which the ,cornish granite wastes1 nor think how improbable it is1 that the conditions necessary to a rocking-stone1 whether produced by nature or art1 should have remained the same for sixteen or seventeen hundred years4 #cef4 ,besides the gradual waste to which stones exposed to the atmosphere are necessarily subject1 those of a great size appear to be liable to splitting1 and dividing into large portions1 no doubt from their weight4 ,this may be observed in almost all stones that happen to be in such circumstances as we are now considering2 and from this cause the subversion of their balance may be more sudden1 and of greater amount1 than could be expected from their gradual decay4 ,thus1 if to the wasting of a stone at the bottom1 we add the accidents that may befal it in the wasting of its sides1 we see at least the physical possibility of detached stones being put in motion1 merely by their own weight4 ,it is indeed remarkable1 that some of the largest of these stones rest on very narrow bases4 ,those at the foot of ,saleve touch the ground only in a few points3 ,the ,boulder stone of ,borrowdale is supported on a narrow ridge like the keel of a ship1 and is prevented from tumbling by a stone or two1 that serve as a kind of shores to prop it up4 ,very unexpected accidents sometimes happen to disturb the rest of such fragments of rock as have once migrated from their own place4 ,saussure mentions a great mass of lapis ollaris#agi that lies detached on the side of a declivity in the valley of ,urseren1 in the canton of ,uri4 ,the people use this stone as a quarry1 and are working it away on the upper side1 in consequence of which it will probably be soon overset1 and will roll to the bottom of the valley4 ,footnote #agi3 ,voyages aux ,alpes1 tom4 iv4 #ahea4 #ceg4 ,in many instances it cannot be doubted1 that stones of the kind here referred to are the remains of masses or veins of whinstone or granite1 now worn away1 and that they have travelled but a very short way1 or perhaps not at all1 from their original place4 ,many of the large blocks of whinstone which we find in this country1 sometimes single1 and sometimes scattered in considerable abundance over a particular spot1 are certainly to be referred to this cause4 ,but the most remarkable examples of this sort are the stones found at the ,cape of ,good ,hope1 on the hill called ,paarlberg1 which takes its name from a chain of large round stones1 like the pearls of a necklace1 that passes over the summit4 ,two of these1 placed near the highest point1 are called the ,pearl and the ,diamond1 and were mentioned several years ago in the ,philosophical ,transactions4#ahj ,from a more recent account1 these stones appear to be a species of granite1 though the hill on which they lie is composed of sandstone strata4#aha ,the ,pearl is a naked rock1 that rises to the height of #djj feet above the summit of the hill2 the ,diamond is higher1 but its base is less1 and it is more inaccessible4 ,footnote #ahj3 ,vol4 lxviii4 p4 #ajb4 ,footnote #aha3 ,barrow's ,travels into ,southern ,africa1 p4 #fj4 ,from the above stones forming a regular chain1 as well as from the immense size of the two largest1 it is impossible to suppose that they have been moved2 and it is infinitely more probable1 that they are parts of a granite vein1 which runs across the sandstone strata1 and of which some parts have resisted the action of the weather1 while the rest have yielded to it4 ,the whole geological history of this part of ,africa seems highly interesting1 since1 as far as can be collected from the accounts of the ingenious traveller just mentioned1 it consists of horizontal beds of sandstone or limestone1 resting immediately on granite1 or on primary schistus4 ,loose blocks of granite are seen in great abundance at the foot of the ,table ,mountain1 and along the sea shore4 99 99 99 99 99 #ceh4 ,the system which accounts for such phenomena as have been considered in this and some of the preceding notes1 by the operation of a great deluge1 or debacle1 as it is called1 has been already mentioned4 ,in ,dr ,hutton's theory1 nothing whatever is ascribed to such accidental and unknown causes2 and1 though their existence is not absolutely denied1 their effects1 whatever they may have been1 are alleged to be entirely obliterated1 so that they can be referred to no other class but that of mere possibilities4 ,a minute discussion1 however1 of the question1 ,whether there are1 on the surface of the earth1 any effects that require the interposition of an extraordinary cause1 would lead into a longer digression than is suited to this place4 ,i shall briefly state what appear to be the principal objections to all such explanations of the phenomena of geology4 #cei4 ,the general structure of valleys among mountains1 is highly unfavourable to the notion that they were produced by any single great torrent1 which swept over the surface of the earth4 ,in some instances1 valleys diverge1 as it were from a centre1 in all directions4 ,in others1 they originate from a ridge1 and proceed with equal depth and extent on both sides of it1 plainly indicating1 that the force which produced them was nothing1 or evanescent at the summit of that ridge1 and increased on both sides1 as the distance from the ridge increased4 ,the working of water collected from the rains and the snows1 and seeking its way from a higher to a lower level1 is the only cause we know of1 which is subject to this law4 #cfj4 ,again1 if we consider a valley as a space1 which perhaps with many windings and irregularities1 has been hollowed out of the solid rock1 it is plain1 that no force of water1 suddenly applied1 could loosen and remove the great mass of stone which has actually disappeared4 ,the greatest column of water that could be brought to act against such a mass1 whatever be the velocity we ascribe to it1 could not break asunder and displace beds of rock many leagues in length1 and in continuity with the rock on either side of them4 ,the slow working of water1 on the other hand1 or the powers that we see every day in action1 are quite sufficient for this effect1 if time only is allowed them4 #cfa4 ,some valleys are so particularly constructed1 as to carry with them a still stronger refutation of the existence of a debacle4 ,these are the longitudinal valleys1 which have the openings by which the water is discharged1 not at one extremity1 but at the broadside ,such is that on the east side of ,mont ,blanc1 deeply excavated on the confines of the granite and schistus rock1 and extending parallel to the beds of the latter1 from the ,col de la ,segne to the ,col de ,ferret2 its opening is nearly in the middle1 from which the ,dora issues1 and takes its course through a great valley1 nearly at right angles to the chain of the ,alps1 and to the valley just mentioned4 ,from the structure of these valleys1 ,saussure has argued very justly against ,buffon's hypothesis1 concerning the formation of valleys by currents at the bottom of the sea4#ahb ,it affords indeed a complete refutation of that hypothesis3 and it affords one no less complete of the system which ,saussure himself seems on some occasions so much inclined to support4 ,for if it be said1 that this valley was cut out by the current of a debacle1 that current must either have run in the direction of the valley of ,ferret1 or in that of the ,dora1 which issues from it4 ,if it had the direction of the first1 it could not cut out the second2 and if it had the direction of the second1 it could not cut out the first4 ,besides1 the force which excavated this valley must have been nothing at the two extreme points1 viz4 at the ,col de la ,segne and the ,col de ,ferret1 and must have increased with the distance from each4 ,it can have been produced1 therefore1 only by the running of two streams in opposite directions1 on a surface that was but slightly uneven1 these streams at meeting taking a new direction1 nearly at right angles to the former4 ,a clearer proof could hardly be required than is afforded in this case1 that what is now a deep valley was formerly solid rock1 which the running of the waters has gradually worn away2 and that the waters1 when they began to run1 were on a level as high1 at least1 as the tops of those mountains by which the valley is bounded toward the lower side4 ,footnote #ahb3 ,voyage aux ,alpes1 tom4 ii4 #ibj4 #cfb4 ,longitudinal valleys1 with the water bursting out transversely from their sides1 like the preceding1 are by no means confined to mountains of the first order4 ,we have a very good example1 though on a small scale1 of a valley of this sort1 within a few miles of ,edinburgh4 ,the ,pentland ,hills form a double ridge1 separated by a small longitudinal valley1 that runs from ,n4 ,e4 to ,s4 ,w41 the water of which issues from an opening almost in the middle1 and directed towards the south4 ,this1 therefore1 is not the work of any great torrent1 which overwhelmed the country2 for no one direction1 which it is possible to assign to such a torrent1 will afford an explanation1 both of the valley and its outlet4#ahc ,footnote #ahc3 ,in ,scotland there is one valley1 of a kind that ,i believe is extremely rare in any part of the world1 in accounting for which1 the hypothesis of a torrent or debacle might1 if any where1 be employed to advantage4 ,this is the valley which extends across the island1 from ,inverness to ,fort ,william1 or from sea to sea1 being open at both ends1 and very little elevated in the middle4 ,it is nearly straight1 and of a very uniform breadth1 except that towards each end it widens considerably4 ,the bottom1 reckoning transversely1 is flat1 without any gradual slope from the sides towards the middle4 ,from the sides the mountains rise immediately1 and form two continued ridges of great height1 like ramparts or embankments on each side of a large foss4 ,a great part of the bottom of this singular valley is occupied by lakes1 namely1 ,loch ,ness1 ,loch ,oich1 and ,loch ,lochy4 ,its length is about sixty-two miles1 and the point of partition from which the waters run different ways1 viz4 north-east to the ,german ,ocean1 and south-west to the ,atlantic1 is between ,loch ,oich and ,loch ,lochy2 and1 by the estimation of the eye1 ,i should hardly think that it is elevated more than ten or fifteen feet above the surface of either lake4 ,the country on both sides is rugged and mountainous1 and the streams which descend from thence into the valley1 either fall directly into the lakes1 or turn off almost at right angles when they enter the valley4 ,though the bottom of this valley1 therefore1 is every where alluvial1 with the exception1 perhaps1 of a few rocks which appear at the surface1 it is certainly not excavated by the rivers which now flow in it4 ,the direction of the valley1 it is to be observed1 is the same with that of the vertical strata which compose the mountain on either side4 ,here1 then1 we have a valley1 not cut out by the working of any streams which now appear2 and we may therefore make trial of the hypothesis of a debacle4 ,this1 however1 will afford us no assistance2 because1 if we suppose what is now hollow to have been once occupied by the same kind of rock which is on either side1 no force of torrents can have suddenly loosened and removed from its place a body of such vast magnitude4 ,a greater column of water1 than one having for its base a transverse section of the valley1 could not act against it1 and this would have to overcome the cohesion and inertia of a column of rock of the same section1 and of the length of sixty-two miles4 ,it is not hazarding much to affirm1 that no velocity which could be communicated to water1 not even that which it could acquire by falling from an infinite height1 could give to it a force in any degree adequate to this great effect4 ,the explanation of this valley1 which appears to me the most probable1 is the following4 ,it will be shown hereafter1 that there is good reason to suppose1 that1 in most parts of our island1 the relative level of the sea and land has been in past ages considerably higher than it is at present4 ,in such circumstances1 this valley may have been under the surface of the sea1 the highest part of it being scarcely #ajj feet above that level at present4 ,it may have been a kind of sound1 therefore1 or strait1 which connected the ,german ,sea with the ,atlantic2 and the strong currents1 which1 on account of the different times of high water in these two seas1 must have run alternately up and down this strait1 may have produced that flatness of the bottom1 and straightness of the sides1 and that widening at the extremities1 which are mentioned above4 ,in this way1 too1 some difficulties are removed relative to ,loch ,ness1 which is so deep as hardly to be consistent with the indefinite length of the period of waste that must be ascribed to the mountains on each side of it4 ,its depth is said1 where greatest1 not to be less than #ahj fathoms4 ,according to this hypothesis1 it may1 at no very distant period1 have been a part of the bottom of the sea4 #cfc4 ,they who maintain the existence of the debacle1 will no doubt allege1 that though these valleys were not cut out by means of it1 yet others may4 ,but it must be recollected1 that if some of the greatest and deepest valleys on the face of the earth1 such as that just mentioned1 on the east side of ,mont ,blanc1 are thus shown to be the work of the daily wasting of the surface1 what other inequalities can be great enough to require the interposition of a more powerful cause8 ,if a dignus vindice nodus does not exist here1 in what part of the natural history of the earth is it likely to be found8 #cfd4 ,the large masses of rock so often met with at a distance from their original place1 are one of the arguments used for the debacle4 ,it has1 however1 been shown1 that1 supposing a form of the earth's surface considerably different from the present1 especially1 supposing the absence of the valleys which the rivers have gradually cut out1 the transportation of such stones is not impossible1 even by such powers as nature employs at present4 ,now1 without the supposition that the surface was more continuous1 and that its present inequalities did not exist1 no force of torrents1 whatever their velocity and magnitude may have been1 could have produced this transportation4 ,no force of water could raise a stone like the pierre de goutt from the bottom of a valley1 to the top of a steep hail4 ,indeed1 if we suppose a great fragment of rock to be hurried along on a horizontal or an inclined plane1 by the force of water1 the moment it comes to a deep valley1 and has to rise up over an ascent of a certain steepness1 it will remain at rest2 the water itself will lose its velocity1 and the heavy bodies which it carried with it will proceed no farther4 ,thus1 therefore1 we have the following dilemma4 ,if the surface is not supposed to have had a certain degree of uniformity in past times1 a debacle is insufficient for the transportation of stones3 ,if it is supposed to have had that uniformity1 a debacle is unnecessary4 #cfe4 ,another fact1 which has been supposed favourable to the opinion of the action of great torrents at some former period1 is1 that in countries like that round ,edinburgh1 where whinstone hills rise up from among secondary strata1 a remarkable uniformity is observed in the direction of their abrupt faces4 ,thus1 in the country just mentioned1 the steep faces generally front the west1 whiles in the opposite direction1 the slope is gentle1 and the hills decline gradually into the plain4 ,hence it is supposed1 that a torrent1 sweeping from west to east1 has carried off the strata from the west side of these hills1 but1 being obstructed by the whinstone rock1 has left the strata on the east side in their natural place4 ,but1 besides that no force which can ever be ascribed to a torrent could have removed at once bodies of strata #cjj or #djj feet1 nay even #hjj or #ajjj in thickness1 which must have been the case if this were the true explanation of the fact1 there is a circumstance which may perhaps enable us to explain these phenomena without the assistance of any extraordinary cause4 ,the secondary strata in which the whinstone hills are found in this part of ,scotland1 are not horizontal1 but rise or head towards the west1 dipping towards the east4 ,the side1 therefore1 of the whinstone hills which is precipitous1 is the same with that towards which the strata rise4 ,now1 from the manner in which these hills are supposed to have been elevated1 the strata are likely to have been most broken and shattered towards that side1 while1 on the opposite1 they had the support of the whinstone rock4 ,they would become a prey1 therefore1 more easily to the common causes of erosion and waste on the upper side than on the lower4 ,the streams that flowed from the higher grounds would wear them on the former most readily2 and the action of these streams would be resisted by the superior hardness of the whinstone1 just as the great torrent of the debacle is supposed to have been4 ,it should also be observed1 that this fact of the uniform direction of the abrupt faces of mountains1 is often too hastily generalized4 ,in primitive countries1 it is no farther observed than by the steep faces of the mountains being most frequently turned toward the central chain4 ,in ,scotland1 as soon as you leave the flat country1 and enter the ,highlands1 the scarps of the hills face indiscriminately all the points of the compass1 and are directed as often to the east as to the west4 #cff4 ,where the strata are nearly horizontal1 they afford the most distinct information concerning the direction and progress of the wasting of the land4 ,the inclined position of the strata1 which in all other cases must enter for so much into our estimate of the causes which have produced the present inequality of the earth's surface1 disappears there entirely2 and the whole of that inequality is to be ascribed to the operations at the surface1 whether they have been sudden or gradual4 ,a very important fact from a country of this sort1 is related by ,,barrow1 in his ,travels into ,southern ,africa4 ,the mountains about the ,cape of ,good ,hope1 and as far to the north as that ingenious traveller prosecuted his journey1 are chiefly of horizontal strata of sandstone and limestone1 exhibiting the appearance1 on their abrupt sides1 of regular layers of masonry1 of towers1 fortifications1 c4 ,now1 among all these mountains1 he observed1 that the high or steep sides look constantly down the rivers1 while the sloping or inclined sides have just the opposite direction4 ,when1 in travelling northward1 he passed the line of partition1 where the waters from running south take their direction to the north1 he found1 that the gradual slope1 which had hitherto been turned to the north1 was now turned to the south3 ,the abrupt aspect of the mountains1 in like manner1 from facing the south1 was directed to the north2 so that1 in both cases1 the hills turned their backs on the line of greatest elevation4#ahd ,footnote #ahd3 ,barrow's ,travels into ,southern ,africa1 p4 #bde4 ,it is evident1 therefore1 that the form of this land has been determined by the slow working of the streams4 ,the causes which produced the effects here described1 began their action from the line of greatest elevation1 and extended it from thence on both sides1 in opposite directions4 ,this is the most precise character that can mark the alluvial operations1 and distinguish them from the overwhelming power of a great debacle4 #cfg4 ,lastly1 if there were any where a hill1 or any large mass composed of broken and shapeless stones1 thrown together like rubbish1 and neither worked into gravel nor disposed with any regularity1 we must ascribe it to some other cause than the ordinary detritus and wasting of the land4 ,this1 however1 has never yet occurred2 and it seems best to wait till the phenomenon is observed1 before we seek for the explanation of it4 #cfh4 ,these arguments appear to me conclusive against the necessity of supposing the action of sudden and irregular causes on the surface of the earth4 ,in this1 however1 ,i am perhaps deceived3 neither ,pallas1 nor ,saussure1 nor ,dolomieu1 nor any other author who has espoused the hypothesis of such causes1 has explained his notions with any precision2 on the contrary1 they have all spoken with such reserve and mystery1 as seemed to betray the weakness1 but may have concealed the strength of their cause4 ,i have therefore been combating an enemy1 that was in some respects unknown2 and ,i may have supposed him dislodged1 only because ,i could not penetrate to his strongholds4 ,the question1 however1 is likely soon to assume a more determinate form4 ,a zealous friend of ,dr ,hutton's theory1 has lately#ahe declared his approbation of the hypothesis which has here been represented as so adverse to that theory2 and1 from his ability and vigour of research1 it is likely to receive every improvement of which it is susceptible4 ,footnote #ahe3 ,trans4 ,royal ,society ,edin4 vol4 v4 p #fh4 ,,note ,,xix4 #aag4 ,transportation of ,materials by the ,sea4 #cfi4 ,,the existence of the great and extensive operations1 by which the spoils of the land are carried all over the ocean1 and spread out on the bottom of it1 may be supposed to require some further elucidation4 ,we must attend1 therefore1 to the following circumstances4 ,when the detritus of the land is delivered by the rivers into the sea1 the heaviest parts are deposited first1 and the lighter are carried to a greater distance from the shore4 ,the accumulation of matter which would be made in this manner on the coast1 is prevented by the farther operation of the tides and currents1 in consequence of which the substances deposited continue to be worn away1 and are gradually removed farther from the land4 ,the reality of this operation is certain2 for otherwise we should have on the sea shore a constant and unlimited accumulation of sand and gravel1 which1 being perpetually brought down from the land1 would continually increase on the shore1 if nature did not employ some machinery for removing the advanced part into the sea1 in proportion to the supply from behind4 ,the constant agitation of the waters1 and the declivity of the bottom1 are no doubt the causes of this gradual and widely extended deposition4 ,a soft mass of alluvial deposit1 having its pores filled with water1 and being subject to the vibrations of a superincumbent fluid1 will yield to the pressure of that fluid on the side of the least resistance1 that is1 on the side toward the sea1 and thus will be gradually extended more and more over the bottom4 ,this will happen not only to the finer parts of the detritus1 but even to the grosser1 such as sand and gravel4 ,for suppose that a body of gravel rests on a plane somewhat inclined1 at the same time that it is covered with water to a considerable depth1 that water being subject not only to moderate reciprocations1 but also to such violent agitation as we see occasionally communicated to the waters of the ocean2 the gravel1 being rendered lighter by its immersion in the water1 and on that account more moveable1 will1 when the undulations are considerable1 be alternately heaved up and let down again4 ,now1 at each time that it is heaved up1 however small the space may be1 it must be somewhat accelerated in its descent1 and will hardly settle on the same point where it rested before4 ,thus it will gain a little ground at each undulation1 and will slowly make its way towards the depths of the ocean1 or to the lowest situation it can reach4 ,this1 as far as we may presume to follow a progress which is not the subject of immediate observation1 is one of the great means by which loose materials of every kind are transported to a great distance1 and spread out in beds at the bottom of the ocean4 #cgj4 ,the lighter parts are more easily carried to great distances1 being actually suspended in the water1 by which they are very gradually and slowly deposited4 ,a remarkable proof of this is furnished from an observation made by ,lord ,mulgrave1 in his voyage to the ,north ,pole4 ,in the latitude of #fe nearly1 and about #bej miles distant from the nearest land1 which was the coast of ,norway1 he sounded with a line of #fhh fathoms1 or #djih feet2 and the lead1 when it struck the ground1 sunk in a soft blue clay to the depth of ten feet4#ahf ,the tenuity and fineness of the mud1 which allowed the lead to sink so deep into it1 must have resulted from a deposition of the lighter kinds of earth1 which being suspended in the water1 had been carried to a great distance1 and were now without doubt forming a regular stratum at the bottom of the sea4 ,footnote #ahf3 ,phipps's ,voyage1 p4 #gd1 #ada4 #cga4 ,the quantity of detritus brought down by the rivers1 and distributed in this manner over the bottom of the sea1 is so great1 that several narrow seas have been thereby rendered sensibly shallower4 ,the ,baltic has been computed to decrease in depth at the rate of forty inches in a hundred years4 ,the ,yellow ,sea1 which is a large gulf contained between the coast of ,china and the peninsula of ,corea1 receives so much mud from the great rivers that run into it1 that it takes its colour1 as well as its name1 from that circumstance2 and the ,european mariners who have lately navigated it1 observed1 that the mud was drawn up by the ships1 so as to be visible in their wake to a considerable distance4#ahg ,computations have been made of the time that it will require to fill up this gulf1 and to withdraw it entirely from the dominion of the ocean3 but the data are not sufficiently exact to afford any precise result1 and are no doubt particularly defective from this cause1 that much of the earth carried into the gulf by the rivers1 must be carried out of it by the currents and tides1 and the finer parts wafted probably to great distances in the ,pacific ,ocean4#ahh ,the mere attempt1 however1 towards such a computation1 shows how evident the progress of filling up is to every attentive observer2 and1 though it may not ascertain the measure1 it sufficiently declares the reality of the operations1 by which the waste of the present continents is made subservient to the formation of new land4 ,footnote #ahg3 ,staunton's ,account of the ,embassy to ,china1 vol4 i4 p4 #ddh4 ,footnote #ahh3 ,perouse1 in sailing along the coast of ,china1 from ,formosa to the strait between ,corea and ,japan1 though generally fifty or sixty leagues from the land1 had soundings at the depth of forty-five fathoms1 and sometimes at that of twenty-two4 ,atlas du ,voyage de la ,perouse1 ,no4 #dc4 #cgb4 ,sandbanks1 such as abound in the ,german ,ocean1 to whatever they owe their origin1 are certainly modified1 and their form determined1 by the tides and currents4 ,without the operation of these last1 banks of loose sand and mud could hardly preserve their form1 and remain intersected by many narrow channels4 ,the formation of the banks on the coast of ,holland1 and even of the ,dogger ,bank itself1 has been ascribed to the meeting of tides1 by which a state of tranquillity is produced in the waters1 and of consequence a more copious deposition of their mud4 ,even the great bank of ,newfoundland seems to be determined in its extent by the action of the ,gulf stream4 ,in the ,north ,sea1 the current which sets out of the ,baltic1 has evidently determined the shape of the sandbanks opposite to the coast of ,norway1 and produced a circular sweep in them1 of which it is impossible to mistake the cause4 ,in proof of the action here ascribed to the waters of the sea1 in transporting materials to an unlimited extent1 we may add the well known observation1 that the stones brought up by the lead from the bottom of the sea1 are generally round and polished1 hardly ever sharp and angular4 ,this could never happen to stones that were not subject to perpetual attrition4 #cgc4 ,currents are no doubt the great agents in diffusing the detritus of the land over the bottom of the sea4 ,these have been long known to exist2 but it is only since the later improvements in navigation1 that they have been understood to constitute a system of great permanence1 regularity1 and extent1 connected with the trade winds1 and other circumstances in the natural history of the globe4 ,the ,gulf stream was many years since observed to transport the water1 and the temperature of the tropical regions into the climates of the north2 and we are indebted to the researches of ,major ,,rennell1 for the knowledge of a great system of currents1 of which it is only a part4 ,that geographer1 who is so eminent for enriching the details of his science with the most interesting facts in history or in physics1 has shown1 that along the eastern coast of ,africa1 from about the mouth of the ,red ,sea1 a current fifty leagues in breadth sets continually towards the south-west4#ahi ,it doubles the ,cape of ,good ,hope1 runs from thence north-west1 preserving on the whole the direction of the coast1 but reaching so far into the ocean1 that1 about the parallel of ,st ,helena1 its breadth exceeds #ajjj miles4 ,from thence1 as it approaches the line1 its direction is more nearly east2 and meeting in the parallel of #c north1 with a current which has come along the western coast of ,africa from the north1 the two united stretch across the ,atlantic1 in a line somewhat south of west1 and in a very wide and rapid stream4 ,this stream meets the ,american land at ,cape ,st ,roque1 where it is joined by another coming up along the eastern shore of that continent1 and directed towards the north4 ,they proceed northward together till they enter the ,gulf of ,florida1 from which being as it were reflected1 they form the ,gulf stream1 passing along the coast of ,north ,america1 and stretching across the ,atlantic to the ,british ,isles4 ,from thence the current turns to the south1 and1 proceeding down the coast of ,spain and ,africa1 meets the stream ascending from the south1 as already described1 and thus continues in perpetual circulation4 ,the velocity of these currents is not less remarkable than their extent4 ,at the ,cape of ,good ,hope1 the rate is thirty nautical miles in twenty four hours2 in some places forty five2 and under the line seventy seven4 ,when the ,gulf stream issues from the ,straits of ,bahama1 it runs at the rate of four miles an hour1 and proceeds to the distance of #ahjj miles1 before its velocity is reduced to half that quantity4 ,in the parallel of #ch1 near #ajjj miles from the above strait1 the water of the stream has been found ten degrees warmer than the air4 ,footnote #ahi3 ,geography of ,herodotus1 p4 #fgb4 #cgd4 ,the course of the ,gulf stream is so fixed and regular1 that nuts and plants from the ,west ,indies are annually thrown ashore on the ,western ,islands of ,scotland4 ,the mast of a man of war1 burnt at ,jamaica1 was driven several months afterwards on the ,hebrides1#aij after performing a voyage of more than #djjj miles1 under the direction of a current1 which1 in the midst of the ocean1 maintains its course as steadily as a river does upon the land4 ,footnote #aij3 ,pennant's ,arctic ,zoology1 ,introd4 p4 #gj4 ,the great system of currents thus traced through the ,atlantic1 has no doubt phenomena corresponding to it in the ,indian and ,pacific ,oceans1 which the industry of future navigators may discover4 ,the whole appears to be connected with the trade winds1 the figure of our continents1 the temperature of the seas themselves1 and perhaps with some inequalities in the structure of the globe4 ,the disturbance produced by these causes in the equilibrium of the sea1 probably reaches to the very bottom of it1 and gives rise to those counter currents1 which have sometimes been discovered at great depths under the surface4#aia ,footnote #aia3 ,histoire ,naturelle de ,buffon1 ,supplment1 tom4 ix4 p4 #dgi4 #hvo4 ,the great transportation of materials that must result from the action of these combined currents is obvious1 and serves not a little to diminish our wonder1 at finding the productions of one climate so frequently included among the fossils of another4 ,amid all the revolutions of the globe1 the economy of nature has been uniform1 in this respect1 as well as in so many others1 and her laws are the only thing that have resisted the general movement4 ,the rivers and the rocks1 the seas and the continents1 have been changed in all their parts2 but the laws which direct those changes1 and the rules to which they are subject1 have remained invariably the same4 #cge4 ,objections have been made to that translation of materials by the waters of the ocean which is supposed in this theory1 particularly by ,mr ,kirwan1 in his ,geological ,essays2 and1 though ,i might perhaps content myself with the remark already made1 that the ,neptunian system involves suppositions concerning the transportation of solid bodies by the sea1 in the early ages of the world1 as wonderful as those which1 according to our theory1 are common to all ages1 ,i am unwilling to remain satisfied with a mere argumentum ad hominem1 where the fallacy of the reasoning is so easily detected4 #cgf4 ,one of ,mr ,kirwan's objections to the deposition of materials at the bottom of the sea1 is thus stated3 ,,frisi has remarked1 in his mathematical discourses1 that if any considerable mass of matter were accumulated in the interior of the ocean1 the diurnal motion of the globe would be disturbed1 and consequently it would be perceptible2 a phenomenon1 however1 of which no history or tradition gives any account4#aib ,footnote #aib3 ,geol4 ,essays1 p4 #dda4 ,the appeal made here to ,frisi is singularly unfortunate1 as that philosopher has demonstrated the very contrary of ,mr ,kirwan's position1 and has proved1 that the disturbance given to the diurnal motion by the causes here referred to may be real1 but cannot be perceptible4 ,having investigated a formula expressing the law which all such disturbances must necessarily observe1 he concludes1 ,hc autem formul manifestum fiet1 ex iis omnibus variationibus qu in terrestri superficie observari solent1 montium et collium abrasione1 dilapsu corporum ponderosiorum in inferiores telluris sinus1 nullam oriri posse variationem sensibilem diurni mots4 ,nam si statuamus data aliqua annorum periodo terrestrem superficiem ad duos usque pedes abradi undique1 eam vero materi quantitatem ad profunditatem pedum #ajjj dilabi2 erit omne quod inde orietur incrementum velocitatis diurni mots #cjjjj_/7aifchjea7b #a_/abheejfhahd4aic ,footnote #aic3 ,frisii ,opera1 tom4 iii4 p4 #bfi4 ,here1 it is evident1 that ,frisi admits those very changes on the surface which we are contending for1 and shows1 that their tendency is to accelerate the earth's diurnal motion1 but1 by a quantity so small1 that1 in a space of time amounting at least to #bjj years1 the increase of the diurnal motion would only be such a part of the whole as the preceding fraction is of unity4#aid ,footnote #aid3 ,the time requisite for taking away by waste and erosion two feet from the surface of all our continents1 and depositing it at the bottom of the sea1 cannot be reckoned less than #bjj years4 ,the fraction #a_/abheejfhahd1 reduced to parts of a day1 is #a_/adheed of a second2 so that it would require #bjj years to shorten the length of the day1 by the above fraction of a second2 and therefore it would require #adheed times #bjj years1 or #bigajhjj years1 to diminish it an entire second4 ,the accumulated effect1 however1 of all the diminutions during that period1 would amount to much more3 and if we had any perfectly uniform standard to compare the motion of the earth with1 its difference from that standard would increase as the squares of the time1 and the total acceleration would amount to one second in #ggjhj years4 ,whatever relation this bears to the age of the globe itself1 it exceeds more than ten times the age of any historical record4 ,though ,frisius concludes1 as is stated here1 that the acceleration produced in the diurnal motion of the earth1 is far too inconsiderable to become the object of astronomical observation1 he makes a supposition difficult to be reconciled with this conclusion1 namely1 that the acceleration has had a sensible effect on the figure of the earth1 or rather of the sea1 having increased the centrifugal force1 and thereby accumulated the waters under the equator1 in the present1 more than in former ages4 ,such an accumulation1 he thinks agreeable to certain appearances that have been observed respecting the ancient level of the sea4 ,these appearances will be afterwards considered3 it is sufficient to remark here1 that though the fraction1 expressing the increment of the centrifugal force1 must be double that which expresses the acceleration1 it must be too small to have any perceptible effect in elevating the sea1 except after an immense interval of time2 and the compensations which arise from other causes1 probably must prevent it from becoming sensible in any length of time whatsoever4 #cgg4 ,the instance just given may serve as one of many1 to shew what confidence is to be placed in that indigested mass of facts and quotations which ,mr ,kirwan1 without discrimination1 and without discussion1 has brought together from all quarters4 ,he has no intention1 ,i believe1 to deceive his readers2 but we may judge1 from this specimen1 of the precautions he has taken against being deceived himself4 ,in some respects1 the result of ,frisi's investigation must be considered as imperfect4 ,if there were no relative motion in the parts of our globe1 but that by which things descend from a higher to a lower level1 a continual acceleration of its rotation1 though extremely slow1 would take place1 as above computed4 ,but as1 in the interior of the earth1 there are undoubtedly motions of a tendency opposite to those on the surface1 and directed from the centre towards the circumference1 they must produce a retardation in the diurnal revolution2 and from this must arise an inequality1 not uniformly progressive in the same direction1 but periodical1 and confined within certain limits1 as the causes are by which it is produced4#aie ,footnote #aie3 ,even in the descent of bodies from a higher to a lower level at the surface of the earth1 the whole tendency is not to increase the velocity of the earth's rotation1 and many compensations take place1 which1 when the matter is considered only in general1 are necessarily overlooked4 ,this will appear evident1 if we reflect1 that it is not simply the approach of a body towards the centre of the earth1 or its removal from that centre1 which tends to disturb the rotation of the earth2 but its approach to the axis of the earth1 or its removal from that axis4 ,the velocity with which a particle of matter revolves1 whether on the surface1 or in the interior of the globe1 is proportional to its distance from the axis of rotation2 and therefore1 when a body comes nearer to the axis1 it loses a part of the motion which it had before2 which part1 of consequence1 is communicated to the whole mass of the earth1 and therefore tends to increase the velocity with which it revolves4 ,the contrary happens when a body recedes from the axis2 for it then receives an addition to its velocity1 which1 of course1 is taken away from the rotatory motion of the earth4 ,hence1 bodies moving in a horizontal plane1 may increase or diminish the swiftness of the diurnal motion1 according as they move towards the poles or towards the equator2 and those which descend from a higher to a lower level1 disturb the earth's rotation1 much more in consequence of their horizontal1 than of their perpendicular motion4 ,the ,ganges1 for instance1 though its source is probably elevated no less than #gjjj feet above the level of the sea1 tends to retard the earth's rotation1 by bringing its waters1 and the mud contained in them1 from the parallel of #ca to that of #bb1 and so increasing their distance from the earth's axis by more than #a_/ab th part4 ,had the ,ganges flowed towards the north1 as the ,nile does1 its effect would have been just the contrary4 ,in the same manner1 a stone descending from the top of a mountain1 may accelerate or retard the earth's rotation1 according to the direction in which it descends4 ,if it descend on the side of the elevated pole1 it will then produce acceleration1 because its distance from the axis will be diminished2 but if it descend on the side of the depressed pole1 and if the direction in which it is moved1 be over a line less inclined1 than a line drawn from the same point to the depressed pole1 it will then produce a retardation1 because its distance from the axis will be increased4 ,let us suppose1 for example1 that the top of ,mount ,blanc is in latitude #de #di1 and that its height is #bdej toises above the level of the sea4 ,the point at which a line drawn from the top of this mountain1 parallel to the earth's axis1 will meet the superficies of the sea1 7supposing that superficies continued inland from the ,mediterranean71 must be about #bchb toises in horizontal distance1 or about #b-a_/b minutes south of the summit1 that is1 in the parallel of #de #df-a_/b2 and if this parallel be continued all round the globe1 the points of the earth's surface between it and the equator1 are all more distant from the earth's axis than the top of ,mount ,blanc is2 whereas all the points to the north of it are nearer to that axis4 ,a stone1 therefore1 from the top of ,mount ,blanc1 if carried any where to the south of the above parallel1 will retard the earth's diurnal motion2 but if carried any where to the north of the same line1 will accelerate that motion4 ,the same quantity of matter1 however1 carried an equal distance toward the pole1 and toward the equator1 from any point1 will lose more velocity in the former case than it will gain in the latter1 as easily follows from the nature of circle4 ,therefore1 supposing an equal dispersion of the detritus of a mountain in all directions1 the parts that go toward the pole will most disturb the diurnal motion2 and hence a balance on their side1 or in favour of acceleration1 as already observed4 #cgh4 ,mr ,kirwan's second objection is founded on the misapprehension of a well-known fact in the natural history of the earth4 ,rivers1 says this author1 do not carry into the sea the spoils which they bring from the land1 but employ them in the formation of deltas of low alluvial land at their mouths1 according to what ,major ,rennell has proved4 ,the fact of the formation of deltas from the spoils which the rivers carry from the higher grounds1 is perfectly ascertained2 and the detail into which ,major ,rennell has entered in the passage referred to by ,mr ,kirwan1 does credit to the acuteness and accuracy of that excellent geographer4 ,but it is not there asserted1 that rivers employ all the materials which they carry with them1 in the formation of those deltas1 and deliver none of them into the sea4 ,on the contrary1 they carry from the delta itself mud and earth1 which they can deposit no where but in the sea2 and it is this circumstance chiefly that limits the increase of those alluvial lands1 and makes them either cease to increase1 or makes them increase very slowly after a certain period1 though the supply of earth from the higher grounds remains nearly the same4 ,to make ,mr ,kirwan's argument conclusive1 it would be necessary to prove1 that all the mud carried down by the ,nile or the ,ganges1 was deposited on the low lands before these rivers enter the sea2 a thing so obviously absurd1 that nothing but his haste to obtain a conclusion unfavourable to the ,plutonic system1 could have prevented him from perceiving it#aif4 ,footnote #aif3 ,the instance mentioned in the ,geological ,essays1 from the travels of the ,abb ,fortis1 concerning urns thrown into the ,adriatic1 upwards of #adjj years ago1 and not yet covered with mud1 must be explained from peculiar circumstances1 or local causes1 with which we are unacquainted1 as it makes against the deposition of earth near the shore1 and in narrow seas2 a general fact which1 ,i think1 every body admits4 #cgi4 ,a remark which ,major ,rennell has made concerning the mouths of rivers1 in his ,geography of ,herodotus1 deserves ,mr ,kirwan's attention1 though perhaps he may not be able to put on it an interpretation quite so favourable to his system4 ,the remark is1 that the mouths of great rivers are often formed on principles quite opposite to one another1 so that some of them have a real delta or triangle of flat land at their mouths1 while others have an estuary1 or what may not improperly be called a negative delta4 ,of the latter kind are some of the greatest rivers in the world1 the ,plata1 the ,oroonoko and the ,maranon1 and by far the greatest number of our ,european rivers4 ,nobody can doubt1 that the three rivers just named carry with them as much earth as the ,nile1 or the ,euphrates1 or any other river in the world4 ,all this they have deposited in the sea1 and committed to the currents1 which sweep along the shore of the ,american continent1 and by these they have been spread out over the unlimited tracts of the ocean4 ,indeed1 nothing can be more just than ,dr ,hutton's observation1 that where low land is formed at the mouths of rivers1 there the rivers bring down more than the sea is able to carry away2 but that where such land is not formed1 it is because the sea is able to carry off immediately all the deposit which it receives4 #chj4 ,mr ,kirwan has denied on another principle the power of the sea to carry to a distance the materials delivered into it3 ,notwithstanding1 says he1 many particles of earth are by rivers conduced to the sea1 yet none are conveyed in any distance1 but are either deposited at their mouths1 or rejected by currents or by tides2 and the reason is1 because the tide of flood is always more impetuous and forcible than the tide of ebb1 the advancing waves being pressed forward by the countless number behind them1 whereas the retreating are pressed backward by a far smaller number1 as must be evident to an attentive spectator2 and hence it is that all floating things cast into the sea1 are at last thrown on shore1 and not conveyed into the mid regions of the sea1 as they should be if the reciprocal undulations of the tides were equally powerful #aig ,footnote #aig3 ,kirwan's ,geol4 ,essays1 p4 #dci4 #cha4 ,but if the attentive spectator1 instead of trusting to a vague impression1 or listening to some crude theory of undulations1 reflects on one of the most simple facts respecting the ebbing and flowing of the tides1 he will be very little disposed to acquiesce in the above conclusion4 ,he has only to consider1 that the flowing of the tide requires just six hours1 and the ebbing of it likewise six hours2 so that the same body of water flows in upon the shore1 and retreats from it1 in the same time4 ,the quantity of matter moved1 therefore1 and the velocity with which it is moved1 are in both cases the same2 and it remains for ,mr ,kirwan to show in what the difference of their force can possibly consist4 ,the force with which the waves usually break upon our shores1 does not arise from the velocity of the tide being greater in one direction than in another4 ,in the main ocean1 the waves have no progressive motion1 and the columns of water alternately rise and fall1 without any other than a reciprocating motion3 a kind of equilibrium takes place among the undulations1 and each wave being equally acted upon by those on opposite sides1 remains fixed in its place4 ,near the shore this cannot happen2 the water on the land side from its shallowness being incapable of rising to the height necessary to balance the great undulations which are without4 ,the water runs1 therefore1 as it were1 from a higher to a lower level1 spreading itself towards the land side4 ,this produces the breakers on our shores1 and the surf of the tropical seas4 ,a rock or a sandbank coming within a certain distance of the surface1 is sufficient1 in any part of the ocean1 to obstruct the natural succession of undulations2 and1 by destroying the mutual reaction of the waves1 to give them a progressive instead of a reciprocating motion4 #chb4 ,it is1 however1 but from a small distance1 that the waves are impelled against the shore with a progressive motion4 ,the border of breakers that surrounds any coast is narrow1 compared with the distance to which the detritus from the land is confessedly carried2 the water1 while it advances at the surface1 flows back at the bottom2 and these contrary motions are so nearly equal1 that it is but a very momentary accumulation of the water that is ever produced on any shore4 ,if it were otherwise1 and if it were true that the sea throws out every thing1 and carries away nothing1 we should have a constant accumulation of earth and sand along all shores whatsoever1 at least wherever a stream ran into the sea4 ,this1 as is abundantly evident1 is quite contrary to the fact4 ,so1 also1 the bars formed at the mouths of rivers1 after having attained a certain magnitude1 increase no farther1 not because they cease to receive augmentations from the land1 but because their diminution from the sea1 increasing with their magnitude1 becomes at length so great1 as completely to balance those augmentations4 ,when properly examined1 therefore1 the phenomena1 which have been proposed as most inconsistent with the indefinite transportation of stony bodies1 afford very satisfactory proofs of that operation4 #chc4 ,it is true1 that bodies which float in the water1 when carried along on the tops of the waves towards a shelving beach1 having acquired a certain velocity1 are thrown farther in upon the land than the distance they would have floated to1 if they had been simply sustained by the water4 ,the depth of water1 therefore1 at the place where they take the ground1 is not likely to be such as to float them again1 and to carry them out towards the sea4 ,they are1 therefore1 left behind2 and this produces an appearance of a force impelling floating bodies towards the land1 much greater and more general than really takes place4 ,these observations may serve to show1 how unsound the principles are from which ,mr ,kirwan's conclusions are deduced3 they are perhaps more than is necessary for that purpose3 it might have been sufficient to observe1 that the increase of land on the sea shore is limited1 though the augmentation from the land is certainly indefinite1 a proof that the diminution from the sea is constant and equal to the increase4 #chd4 ,mariners1 says ,mr ,kirwan1 were accustomed1 for some centuries back1 to discover their situation1 by the kind of earth or sand brought up by their sounding plummets2 a method which would prove fallacious1 if the surface of the bottom did not continue invariably the same4#aih ,footnote #aih3 ,geol4 ,essays1 p4 #ddj4 ,the fact here stated1 that mariners1 when navigation was more imperfect than it is now1 had very frequent recourse to this method1 and that they still use it occasionally1 is very true4 ,but from this1 the only inference that can be fairly deduced is1 that the changes at the bottom of the sea are very slow1 and the variation but little2 not merely from one year to another1 but even from one century to another4 ,the rules by which the mariner judged of his position from the quality of the earth which the lead brought up1 and which were deduced no doubt from observations made at no very great distance of time1 might be sufficient for his purpose1 though a slow change had been all the while going forward4 ,such observations could at best have little accuracy1 and could not be affected by small variations4 ,it is the slowness of the change1 that makes the experience of one age applicable1 in this1 as in innumerable other instances1 to the observations of the next4 ,if a long interval is taken1 we will look in vain for the same uniformity of results4 ,a pilot1 who would at present judge of his position in the ,german ,ocean1 by comparing his soundings with those taken by ,,pytheas1 7supposing them known7 in his navigation of that sea1 more than #bjjj years ago1 could hardly be expected to determine his latitude and longitude with great exactness2 and ,i know not if the most zealous advocate for the immutability of the earth's surface1 would be willing to trust his safety in a ship that was guided by such antiquated rules4 ,,note ,,xx4 #aah4 ,inequalities in the ,planetary ,motions4 #che4 ,the assertion that1 in the planetary motions1 we discover no mark1 either of the commencement or termination of the present order1 refers to the late discoveries of ,,la ,,grange and ,,la ,,place1 which have contributed so much to the perfection of physical astronomy4 ,from the principle of universal gravitation1 these mathematicians have demonstrated1 that all the variations in our system are periodical2 that they are confined within certain limits2 and consist of alternate diminution and increase4 ,the orbits of the planets change not only their position1 but even their magnitude and their form3 the longer axis of each has a slow angular motion2 and1 though its length remains fixed1 the shorter axis increases and diminishes1 so that the form of the orbit approaches to that of a circle1 and recedes from it by turns4 ,in the same manner1 the obliquity of the ecliptic1 and the inclination of the planetary orbits1 are subject to change2 but the changes are small1 and1 being first in one direction1 and then in the opposite1 they can never accumulate so as to produce a permanent or a progressive alteration4 ,thus1 in the celestial motions1 no room is left for the introduction of disorder2 no irregularity or disturbance1 arising from the mutual action of the planets1 is permitted to increase beyond certain limits1 but each of them1 in time1 affords a correction for itself4 ,the general order is constant1 in the midst of the variation of the parts2 and1 in the language of ,la ,place1 there is a certain mean condition1 about which our system perpetually oscillates performing small vibrations on each side of it1 and never receding from it far4#aii ,the system is thus endowed with a stability1 which can refill the lapse of unlimited duration2 it can only perish by an external cause1 and by the introduction of laws1 of which at present no vestige is to be traced4 ,footnote #aii3 ,exposition du ,systme du ,monde1 par ,la ,place1 ,livre iv4 chap4 #f4 p4 #aii4 #b;d edit4 #chf4 ,the same calculus to which we are indebted for these sublime conclusions1 informs us of two circumstances1 which mark the law here treated of as an effect of wise design1 to the entire exclusion both of necessity and chance4 ,one of these circumstances consists in the planetary motions being all in the same direction1 or all in consequentia as it is called by the astronomers4 ,this is essential to the compensation and stability above mentioned3#bjj had one planet circulated round the sun in a direction from east to west1 and another in a direction from west to east1 the disturbances they would have produced on one another's motion would not necessarily have been periodical2 their irregularities might have continually increased1 and they might have deviated in the course of ages from their original condition1 beyond any limits that can be assigned4 ,footnote #bjj3 ,la ,place1 ibid4 ,the other circumstance1 on which the stability of our system depends1 is the small eccentricity of the planetary orbits1 or their near approach to circles4 ,were their orbits very eccentric1 an opening would be given to progressive change1 that might so far increase1 as to prove the destruction of the whole4 ,but neither the movement of all the planets in the same direction1 nor the small eccentricity of their orbits1 can be ascribed to accident1 since that either of these should happen by chance1 in as many instances as there are planets1 both primary and secondary1 is almost infinitely improbable4 ,again1 that any necessity in the nature of things should have either determined the direction of the planetary motions1 or proportioned the quantity of them to the intensity of the central force1 cannot be admitted1 as these are things unavoidably conceived to be quite independent of one another4 ,it remains1 therefore1 that we consider the laws1 which make the disturbances in our system correct themselves1 and by that means give firmness and permanence to it1 as a proof of the consummate wisdom with which the whole is constructed4 #chg4 ,the geological system of ,dr ,hutton1 resembles1 in many respects1 that which appears to preside over the heavenly motions4 ,in both1 we perceive continual vicissitude and change1 but confined within certain limits1 and never from a certain1 mean condition1 which is such1 that1 in the lapse of time1 the deviations from it on the one side1 must become just equal to the deviations from it on the other4 ,in both1 a provision is made for duration of unlimited extent1 and the lapse of time has no effect to wear out or destroy a machine1 constructed with so much wisdom4 ,where the movements are all so perfect1 their beginning and end must be alike invisible4 ,,note ,,xxi4 #abb4 ,changes in the apparent ,level of the ,sea4 #chh4 ,in speaking of the natural epochs marked out by the phenomena of the mineral kingdom1 we have supposed a greater simplicity1 and separation of effects from one another1 than probably takes place in nature4 ,we have1 for instance1 abstracted1 in speaking of the waste and degradation of the land1 from that elevation which may have been carried on at the same time4 ,this appeared necessary to be done1 in order to simplify as much as possible the view that was to be given of the whole2 but there can be no doubt1 that1 while the land has been gradually worn down by the operations on its surface1 it has been raised up by the expansive forces acting from below4 ,there is even reason to think1 that the elevation has not been uniform1 but has been subject to a kind of oscillation1 insomuch1 that the continents have both ascended and descended1 or have had their level alternately raised and depressed1 independently of all action at the surface1 and this within a period comparatively of no great extent4 ,it will be easily understood1 that the facts we are going to state1 each taken singly1 prove nothing more than a change of the line in which the surface of the sea intersects the surface of the land1 leaving it uncertain to which of the two the change ought really to be ascribed4 ,taken in combination1 however1 these facts may determine what each of them separately cannot ascertain4 ,i shall first1 therefore1 mention some of the principal observations relative to the change above mentioned1 and shall then compare them1 in order to discover whether it is most probable that this change has been produced by the motion of the land or of the sea4 #chi4 ,if we begin with examining the coasts of our own island1 we shall find clear evidence every where1 that the sea once reached higher up upon the land than it does at present4 ,the marks of an ancient sea beach are to be seen beyond the present limits of the tide1 and beds of sea shells1 not mineralized1 are found in the loose earth or soil1 sometimes as high as thirty feet above the present level of the sea4 ,some of these on the shores of the ,frith of ,forth are very well known1 and have been often mentioned4 ,indeed1 on the shores of that frith1 many monuments appear1 which would seem to carry the difference between the present and the ancient level of the sea1 to more than forty feet4 ,the ground on which the ,botanic ,garden of ,edinburgh is situated1 after a thin covering of soil is removed1 consists entirely of sea sand1 very regularly stratified1 with layers of a black carbonaceous matter1 in thin lamell1 interposed between them4 ,shells ,i believe are but rarely found in it1 but it has every other appearance of a sea beach4 ,the height of this ground above the present level of the sea is certainly not less than forty feet4 #cij4 ,on almost every part of the coast where the rocks do not rise quite abrupt and precipitous from the sea1 similar marks of the lowering of the sea1 or the rising of the land1 may be observed4 ,on the shores opposite to ours1 the same appearances are remarked4 ,the author of the ,lettre ,critique to ,m4 de ,buffon1 tells us1 that he had found the bottom of a bason at ,dunkirk1 which he had reason to think was dug about #iej years ago1 ten feet and a half above the present low water mark1 though it must have been originally under it4 ,the bottom of this bason is in the native chalk4 ,from this1 the same author concludes1 that the sea at ,dunkirk lowers its level at the rate of an inch nearly in seven years4 ,the observation was made in #agfb1 7,lettre ,m4 le ,comte de ,buffon1 c4 p4 #ee47bja ,footnote #bja3 ,in the county of ,suffolk1 near ,wood ,bridge1 at the distance of seven or eight miles from the sea1 are the ,crag-pits1 in which prodigious quantities of sea shells are discovered1 many of them perfect and quite solid1 7,pennant's ,arctic ,zoology1 ,introd4 p4 #f47 ,lincolnshire affords various proofs of the same kind2 but some other circumstances in the appearance of that coast1 just about to be taken notice of1 indicate changes of a more complicated nature4 #cia4 ,the shores of the ,low ,countries1 and of ,holland1 have been often instanced in proof of the same kind of changes1 and it has been supposed1 that1 independently of those artificial barriers which at present exclude the waters of the ocean from overflowing a great part of this tract1 nature herself has brought it nearer to the surface than it had formerly been4 ,it is indeed certain1 that those countries1 to a very great extent inland1 have either been under the sea at some period1 by no means remote if compared with the great revolutions of the globe1 or that they are entirely alluvial1 and of the same sort with the ,deltas formed at the mouths of rivers4 ,the relative changes1 however1 of the sea and land on this tract1 have been differently represented1 and ,i am unwilling1 on that account1 to found any argument on them4 #cib4 ,if we proceed farther to the north1 to the shores of the ,baltic for instance1 we have undoubted evidence of a change of level in the same direction as on our own shores4 ,the level of this sea has been represented as lowering at so great a rate as #dj inches in a century4 ,celsius observed1 that several rocks which are now above water1 were not long ago sunken rocks1 and dangerous to navigators2 and he particularly took notice of one1 which1 in the year #afhj1 was on the surface of the water1 and in the year #agia was #bj-a_/b ,swedish inches above it4 ,from an inscription near ,asp1 in the lake ,melar1 which communicates with the ,baltic1 engraved1 as is supposed1 about five centuries ago1 the level of the sea appears to have sunk in that time no less than #ac ,swedish feet4#bjb ,all these facts1 with many more which it is unnecessary to enumerate1 make the gradual depression1 not only of the ,baltic1 but of the whole northern ocean1 a matter of certainty4 ,footnote #bjb3 ,frisii ,opera1 tom4 iii4 p4 #bgd4 #cic4 ,supposing these changes of level between the sea and land to be sufficiently ascertained1 the supposition which at first occurs is1 that the motion has been in the sea rather than in the land1 and that the former has actually descended to a lower level4 ,the imagination naturally feels less difficulty in conceiving1 that an unstable fluid like the sea1 which changes its level twice every day1 has undergone a permanent depression in its surface1 than that the land1 the terra firma itself1 has admitted of an equal elevation4 ,in all this1 however1 we are guided much more by fancy than reason2 for1 in order to depress or elevate the absolute level of the sea1 by a given quantity1 in any one place1 we must depress or elevate it by the same quantity over the whole surface of the earth2 whereas no such necessity exists with respect to the elevation or depression of the land4 ,to make the sea subside #cj feet all round the coast of ,great ,britain1 it is necessary to displace a body of water #cj feet deep over the whole surface of the ocean4 ,the quantity of matter to be moved in that way is incomparably greater than if the land itself were to be elevated2 for though it is nearly three times less in specific gravity1 it is as much greater in bulk1 as the surface of the ocean is greater than that of this island4 #cid4 ,besides1 the sea cannot change its level1 without a proportional change in the solid bottom on which it rests4 ,though there be reason to suppose that such changes in the bottom do actually take place1 yet they are probably much slower and more imperceptible than those which we are here considering4 ,it is evident1 therefore1 that the simplest hypothesis for explaining those changes of level1 is1 that they proceed from the motion1 upwards or downwards1 of the land itself1 and not from that of the sea4 ,as no elevation or depression of the sea can take place1 but over the whole1 its level cannot be affected by local causes1 and is probably as little subject to variation as any thing to be met with on the surface of the globe4 #cie4 ,other observations1 however1 made on different shores from the preceding1 give greater certainty to this conclusion1 and make it clear1 that the motion or change which we are now treating of is not to be ascribed to the sea itself4 ,the observations just mentioned prove1 that the level of the ,north ,sea is lower now than it was heretofore2 but it appears1 that in the ,mediterranean1 the opposite takes place4 ,very accurate observations made by ,,manfredi1 render it certain1 that the superficies of the ,hadriatic was higher about the middle of the last century1 than toward the beginning of the ,christian era4 ,some repairs that were carrying on in the cathedral church of ,ravenna1 in the year #agca1 afforded him an opportunity of observing1 that the ancient1 and probably original1 pavement1 was four feet and a half below the present1 and nearly a foot under the level of the sea at high water4#bjc ,now1 when the church was built1 this cannot have been the position of the pavement1 relatively to the level of the sea1 for it would have subjected the floor to be under water twice in twenty-four hours1 and must have done so the more unavoidably1 because at that time 7the beginning of the fifth century7 the walls of ,ravenna were washed by the sea4 ,the fact that this pavement is under the high-water mark1 by the quantity just mentioned1 was ascertained by actual levelling4 ,this result was confirmed by similar facts1 observed by ,,zendrini at ,venice4 ,footnote #bjc3 ,commentarii ,academi ,bononiensis1 tom4 ii4 pars #ama1 p4 #bcg1 c4 and pars #b;da1 p4 #a4 c4 #cif4 ,manfredi himself attributes all this to the elevation of the surface of the sea1 and has entered into a long calculation to ascertain at what rate that surface may be supposed to rise1 on account of the earth and sand brought down by the rivers1 and spread out over the bottom of the sea4 ,but as the fact of the rise of the level of the sea is not general1 and as the contrary is observed in the north seas1 as already proved1 this hypothesis will not explain the apparent rise in the level of the ,hadriatic4 #cig4 ,though a local subsidence1 or settling of the ground1 could hardly account for this change1 the pavement being perfect in its level1 and the walls of the cathedral without any shake1 yet a subsidence that has extended to a great tract1 as to the whole of ,italy1 if the mass moved has continued parallel to itself1 and changed its place slowly1 will agree very well with the appearances4 ,the facts here stated are also the more deserving of attention1 that about ,ravenna1 the land1 at the same time that it has sunk in its level1 has extended its surface1 and has encroached on the sea4 ,since the time of ,,augustus1 the line of the coast has been carried farther out by about three miles4#bjd ,this last is the undoubted effect of the degradation of the land by the rivers2 and here we have very clear evidence of the forces1 both under and above the surface1 producing their respective effects at the same time1 so that while the surface is raised by earth brought down by the rivers1 every given point in the ground is depressed and let down to a lower level4#bje ,footnote #bjd3 ,manfredi1 ibid4 ,footnote #bje3 ,on the coast of ,dalmatia also1 the rising of the level of the sea has been remarked1 particularly at the ruins of ,diocletian's palace of ,spalatro4 #cih4 ,on the southern coast of ,italy similar facts have been observed4 ,,breislac1 in his ,topographia ,fisica della ,campagnia di ,roma1#bjf from certain appearances in the ,gulfs of ,baja and ,naples1 concludes1 that at the beginning of the ,christian era1 the level of the sea was lower on that part of the coast than it is now4 ,the facts which he mentions are the following3 #amo1 ,the remains of an ancient road are now to be seen in the ,gulf of ,baja at a considerable distance from the land4 #b;do1 ,some ancient buildings belonging to ,porto ,giulio are at present covered by the sea4 #ctio1 ,ten columns of granite at the foot of ,monte ,nuovo1 which appear to have belonged to the ,temple of the ,nymphs1 are also nearly covered by the sea4 #dto1 ,the pavement of the ,temple of ,serapis is now somewhat lower than the high water mark1 though it cannot be supposed that this edifice when built was exposed to the inconvenience of having its floor frequently under water4 #eto1 ,the ruins of a palace1 built by ,tiberius in the island of ,caprea1 are now entirely covered by the sea4 ,footnote #bjf3 ,cap4 vi4 p4 #cjj4 ,thus1 it appears that the level of the sea is sinking in the more northern latitudes1 and rising in the ,mediterranean1 and it is evident that this cannot happen by the motion of the sea itself4 ,the parts of the ocean all communicating with one another1 cannot rise in one place and fall in another2 but1 in order to maintain a level surface1 must rise equally or fall equally over the whole of its extent4 ,if1 therefore1 we place any confidence in the preceding observations1 and they are certainly liable to no objection1 either from their own nature or the character of the observers1 we must consider it as demonstrated1 that the relative change of level has proceeded from the elevation or depression of the land itself4 ,this agrees well with the preceding theory1 which holds1 that our continents are subject to be acted upon by the expansive forces of the mineral regions2 that by these forces they have been actually raised up1 and are sustained by them in their present situation4 #cii4 ,according to some other facts stated by the same ingenious author1 it appears1 that on the coast of ,italy the progress of the sea in ascending1 or of the land in descending1 has not been uniform during the period above mentioned1 but that different oscillations have taken place2 so that1 from about the beginning of the ,christian era1 till some time in the middle ages1 the sea rose to be sixteen feet higher than at present1 from which height it has descended till it became lower than it is now1 and from that state of depression it is now rising again4 ,breislac infers this from two facts1 which he combines very ingeniously with the preceding1 viz4 the remains of some ancient buildings1 at the foot of ,monte ,nuovo1 five or six feet above the present level of the sea1 in which are found the shells of some of those little marine animals that eat into stone3 ,and again1 the marble columns of the temple of ,serapis1 which are also perforated by pholades1 to the height of sixteen feet above the ground4 ,all these changes ,breislac ascribes to the motion of the sea itself2 a supposition which1 as we have seen1 cannot possibly be admitted1 since nothing can permanently affect the level of the sea in one place1 which does not affect it in all places whatsoever4 #djj4 ,appearances1 which indicate such alternations as have just been mentioned in the level of the sea1 are to be met with on some other coasts4 ,in ,england1 on the coast of ,lincolnshire1 the remains of a forest have been observed1 which are now entirely covered by the sea4#bjg ,the submarine stratum which contains the remains of this forest1 can be traced into the country to a great distance1 and is found throughout all the fens of ,lincolnshire4 ,the stratum itself is about four feet thick2 it is covered in some places by a bed of clay sixteen feet thick1 and under it for twenty feet more is a bed of soft mud1 like the scourings of a ditch1 mixed with shells and silt4 ,footnote #bjg3 ,phil4 ,trans4 #agii1 p4 #ade4 ,here then we have a stratum which must have been once uppermost on the surface of the dry land1 though one part of it is now immersed under the sea1 and another covered with earth1 to the depth of sixteen feet4 ,a change of level in the sea itself will not explain these appearances3 they can only be explained by supposing the whole tract of land to have subsided1 which is the hypothesis adopted by the author of the description in the ,transactions1 ,m4 ,,corria ,,de ,,serra2 the subsidence1 however1 is not here understood to arise from the mere yielding of some of the strata immediately underneath1 but is conceived to be a part of that geological system of alternate depression and elevation of the surface1 which probably extends to the whole mineral kingdom4 ,to reconcile all the different facts1 ,i should be tempted to think1 that the forest which once covered ,lincolnshire1 was immersed under the sea by the subsidence of the land to a great depth1 and at a period considerably remote2 that when so immersed1 it was covered over with the bed of clay which now lies on it1 by deposition from the sea1 and the washing down of earth from the land2 that it has emerged from this great depth till a part of it has become dry land2 but that it is now sinking again1 if the tradition of the country deserves any credit1 that the part of it in the sea is deeper under water at present than it was a few years ago4 ,this might also serve to reconcile1 in some measure1 the phenomena of this submarine forest with the appearances which indicate an extension of the land on the coast of ,lincolnshire4 ,indeed the extension of the land is no direct proof1 either of its own elevation1 or of the depression of the sea1 as we may conclude from the instance of ,ravenna already mentioned4 #dja4 ,we have concluded from the facts stated above1 that the level of the sea rises in the ,mediterranean1 and sinks in the more northern latitudes2 and thence some have suspected1 that the level of the sea had in general a tendency to rise towards the equator1 and to sink towards the poles4 ,this is the notion of ,frisi1 as has been already remarked1 and he suggests1 that this rise of the sea may be owing to a slight acceleration in the earth's diurnal motion4 ,but there are facts which show1 that between the tropics the relative level of the sea and land has sunk1 and is lower at present than it was at some former period1 probably not extremely remote4 ,the opinion of ,frisi1 therefore1 is unsupported by observation1 and1 as has been already shown1 cannot be justified from theory4 ,between the tropics1 islands are formed from the mere accumulation of coral2 and it is the peculiarity of those regions1 to produce rocks that have not passed through the usual process of mineral consolidation4#bjh ,the islets1 however1 which are thus formed1 must have their bases laid on a solid rock1 though perhaps at a great depth2 and it is not probable1 that after they are once raised above the surface of the sea1 they can still rise farther1 except by some elevation of the rock which serves as their foundation4#bji ,now1 at ,palmerston island1 which comprehends nine or ten low islets1 that may be reckoned the heads of a great reef of coral rock1 ,captain ,cook informs us of his having seen1 far beyond the reach of the sea1 even in the most violent storms1 elevated coral rocks1 which1 on examination1 appeared to have been perforated in the same manner that the rocks are that now compose the outer edge of the reef4 ,this evidently shows1 he adds1 that the sea had formerly reached so far2 and some of these perforated rocks were almost in the centre of the island4#baj ,footnote #bjh3 ,dr ,foster1 in his ,voyage round the ,world1 7vol4 ii4 p4 #adf17 gives an instance in the ,south ,sea ,islands1 where the surface of the island1 though entirely a coral rock1 was raised forty feet above the level of the sea4 ,footnote #bji3 ,a very curious account of the formation of such islands is given by ,a4 ,dalrymple1 ,esq41 in the ,philosophical ,transitions1 vol4 lvii4 p4 #cid4 ,footnote #baj3 ,cook's ,third ,voyage1 vol i4 p4 #bba4 ,the same excellent navigator1 giving an account of the peninsula at ,cape ,denbigh1 remarks3 ,it appeared to me1 that this peninsula must have been an island in remote times2 for there were marks of the sea having flowed over the isthmus4 #djb4 ,we are here touching on one of those subjects1 where we feel much the want of accurate and ancient observations1 and where it is not from the infancy1 but the maturity of science that any thing approaching to certainty can be looked for4 ,the utmost that we can expect at present1 is an anticipation1 which future ages must certainly modify and correct4 ,the best thing1 in the mean time1 that can be done for the advancement of this branch of geological knowledge1 is to ascertain with exactness the relative level of the sea1 and of such points upon the land as can be distinctly marked1 and pointed out to succeeding ages4 ,this is not so easy as it may at first appear4 ,where every object changes1 it is difficult to find a measure of change1 or a fixed point from which the computation may begin4 ,the astronomers already feel this inconvenience1 and when they would refer their observations to an immoveable plane1 that shall preserve its position the same in all ages1 they meet with difficulties1 which cannot be removed but by a profound mathematical investigation4 ,in geology1 we cannot hope to be delivered from this embarrassment in the same manner2 and we have no resource but to multiply observations of the difference of level2 to make them as exact as possible1 and to select points of comparison that have a chance of being long distinguished4 ,the improvements in barometrical measurements1 which give such facility to the determination of heights1 along with so considerable a degree of accuracy1 will furnish an accumulation of facts that must one day be of great value to the geologist4 ,,note ,,xxii4 #abc4 ,fossil ,bones4 #djc4 ,the remains of organized bodies1 at present included in the solid parts of the globe1 may be divided into three classes4 ,the first consists of the shells1 corals1-and even bodies of fish1 and amphibious animals1 which are now converted into stone1 and make integrant parts of the solid rock4 ,all these are parts of animals that existed before the formation of the present land1 or even of the rocks whereof it consists4 ,these remains have been already treated of1 and the evidence which they furnish must ever be regarded as of the utmost importance in the theory of the earth4 ,the second class consists of remains1 which1 by the help of stalactitical concretions1 are converted into stone4 ,these are the exuvi of animals1 which existed on the very same continents on which we now dwell1 and are no doubt the most ancient among their inhabitants1 of which any monument is preserved4 ,in comparison of the first class1 they must1 nevertheless1 be considered as of very modern origin4 #djd4 ,the third class consists of the bones of animals found in the loose earth or soil2 these have not acquired a stony character1 and their nature appears to be but little changed1 except by the progress of decomposition and of mouldering into earth4 ,no decided line can be drawn between the antiquity of this and the preceding class1 as there may be between the preceding and the first4 ,in some instances1 the objects of this third class may be coeval with those of the second2 in general1 they must be accounted of later origin1 as they are certainly not preserved in a manner so well fitted for long continuance4 #dje4 ,the animal remains of the second class1 are generally found in the neighbourhood of limestone strata1 and are either enveloped or penetrated by calcareous1 or sometimes ferruginous matter4 ,of this sort are the bones found in the rock of ,gibraltar1 and on the coast of ,dalmatia4 ,the latter are peculiarly marked for their number1 and the extent of the country over which they are scattered1 leaving it doubtful whether they are the work of successive ages1 or of some sudden catastrophe that has assembled in one place1 and overwhelmed with immediate destruction1 a vast multitude of the inhabitants of the globe4 ,these remains are found in greatest abundance in the islands of ,cherso and ,osero 2 end always in what the ,abb ,,fortis calls an ocreo-stalactitic earth4 ,the bones are often in the state of mere splinters1 the broken and confused relics of various animals1 concreted with fragments of marble and lime1 in clefts and chasms of the strata4#baa ,sometimes human bones are said to be found in these confused masses4 ,footnote #baa3 ,travels into ,dalmatia1 p4 #ddi4 #djf4 ,a very remarkable collection of bones in this state is found in the caves of ,bayreuth in ,franconia4 ,many of these belong1 as is inferred with great certainty from the structure of their teeth1 to a carnivorous animal of vast size1 and having very little affinity to any of those that are now known4 ,the bones are found in different states1 some being without any stalactitical concretion1 and having the calcareous earth still united to the phosphoric acid1 so that they belong to the third1 rather than the second1 of the preceding divisions4 ,in others1 the phosphoric acid has wholly disappeared1 and given place to the carbonic4 ,the number of these bones1 accumulated in the same place1 is matter of astonishment1 when it is considered1 that the animals to which they belonged were carnivorous1 so that more than two can never have lived in the same cavern at the same time4 ,the caves of ,bayreuth seem to have been the den and the tomb of a whole dynasty of unknown monsters1 that issued from this central spot to devour the feebler inhabitants of the woods1 during a long succession of ages1 before man had subdued the earth1 and freed it from all domination but his own4 #djg4 ,the fossil bones of the second and third class1 but chiefly of the third1 have now afforded matter of conjecture and discussion for more than a century4 ,the facts with respect to them are very numerous and interesting1 but can be considered here only very generally4 ,the remains of this kind1 consist of the bones only of large animals1 so that they have generally been compared with those of the elephant1 the rhinoceros1 the hippopotamus1 or other animals of great size ,the bones of smaller animals have also been found1 but much more rarely than the other4 ,it is usually remarked1 that the bones thus discovered in the earth are larger than those of the similar living animals4 ,another general fact concerning these remains1 is1 that they are found in all countries whatsoever1 but always in the loose or travelled earth1 and never in the genuine strata4 ,since the year #afif1 when the attention of the curious was called to this subject1 by the skeleton of an elephant dug up in ,thuringia1 and described by ,tentzelius1#bab there is hardly a country in ,europe which has not afforded instances of the same kind4 ,fossil bones1 particularly grinders and tusks of elephants1 have been found in other places of ,germany1 in ,poland1 ,france1 ,italy1 ,britain1 ,ireland1 and even ,iceland4#bac ,two countries1 however1 afford them in greater abundance by far than any other part of the known world2 namely1 the plains of ,siberia in the old continent1 and the flat grounds on the banks of the ,ohio in the new4#bad ,footnote #bab3 ,phil4 ,trans4 vol4 xix4 p4 #geg4 ,footnote #bac3 ,a grinder of an elephant found in ,iceland1 is described by ,bartholinus1 ,acta ,hafniens4 vol4 i4 p4 #hc4 ,footnote #bad3 ,the fossil bones on the ,ohio are described in two papers by ,mr ,p4 ,collinson1 ,phil4 ,trans4 vol4 lvii4 p4 #dfd and #dfh4 #djh4 ,when the bones in ,siberia were first discovered1 they were supposed to belong to an animal that lived under ground1 to which they gave the name of the mammouth2 and the credit bestowed on this absurd fiction1 is a proof of the strong desire which all men feel of reconciling extraordinary appearances with the regular course of nature4 ,much skill1 however1 in natural history was not required to discover that many of the bones in question resembled those of the elephant1 particularly the grinders and the tusks of that animal4 ,others resembled the bones of the rhinoceros2 and a head of that kind1 having the hide preserved upon it1 was found in ,siberia1 and is still in the imperial cabinet at ,petersburgh4 ,pallas has described the fossil bones which he found in the museum at ,petersburgh1 on his being appointed to the superintendence of it1 and enumerates1 not only bones that belong1 in his opinion1 to the elephant and rhinoceros1 but others that belong to a kind of buffalo1 very different from any now known1 and of a size vastly greater4#bae ,he has also described1 in another very curious memoir1 the bones of the same kind that he met with in his travels through the north-east parts of ,asia4 ,footnote #bae3 ,novi ,comment ,petrop4 tom4 xiii4 7#agfh17 p4 #dcf1 and tom4 xvii4 p4 #egf1 c4 ,the fossil bones found on the banks of the ,ohio1 resemble in many things those of ,siberia2 like them they are contained in the soil or alluvial earth1 and never in the solid strata2 like them too they are no otherwise changed from their natural state1 than by being sometimes slightly calcined at the surface2 they are also of great size1 and in great numbers1 being probably the remains of several different species4 #dji4 ,two inquiries concerning these bones have excited the curiosity of naturalists2 first1 to discover among the living tribes at present inhabiting the earth1 those to which the fossil remains may with the greatest probability be referred2 and1 secondly1 to find out the cause why these remains exist in such quantities1 in countries where the animals to which they belong1 whatever they be1 are at present unknown4 ,the solution of the first of these questions1 is much more within our reach than the second1 and at any rate must be first sought for4 ,on the authority of so eminent a naturalist as ,pallas1 the bones from ,siberia may safely be referred to the elephant1 the rhinoceros1 and buffalo1 as mentioned above1 though perhaps to varieties of them with which we are not now acquainted4 ,with respect to the bones of ,north ,america1 the question is more doubtful1 for they have this particular circumstance attending them1 viz4 that along with the thighbones1 tusks1 c4 which might be supposed to belong to the elephant1 grinders are always found of a structure and form entirely different from the grinders of that animal4#baf ,some naturalists1 particularly ,m4 ,,daubenton1 referred these grinders to the hippopotamus2 but ,dr ,w4 ,,hunter appears to have proved1 in a very satisfactory manner1 that they cannot have belonged to either of the animals just mentioned1 but to a carnivorous animal of enormous size1 the race of which1 fortunately for the present inhabitants of the earth1 seems now to be entirely extinct4#bag ,the foundation of ,dr ,hunter's opinion is1 that in these grinders the enamel is merely an external covering2 whereas1 in the elephant1 and other animals destined to live on vegetable food1 the enamel is intermixed with the substance of the tooth4#bah ,footnote #baf3 ,see ,mr ,collinson's papers1 above referred to4 ,phil4 ,trans4 vol4 lvii4 ,footnote #bag3 ,phil4 ,trans4 vol4 lviii4 p4 #c1 c4 ,footnote #bah3 ,a fossil grinder in the collection of ,,john ,,macgowan1 ,esq4 of ,edinburgh1 answers nearly to ,mr ,collinson's description1 and is very well represented by the figure which accompanies it4 ,this grinder weighs four pounds one-fourth avoirdupois2 the circumference of the corona is eighteen inches2 the coat of enamel is one-fourth of an inch thick2 there are five double teeth2 in ,mr ,collinson's specimen there are only four4 #daj4 ,though this argument appears to be of considerable weight1 yet ,,camper1 who was greatly skilled in comparative anatomy1 and who had studied this subject with particular attention1 was of opinion1 that these grinders belong to a species of elephant4 ,this opinion he states in a letter to ,pallas1 who had found grinders and other bones of this same animal1 on the western declivity of the ,ural mountains4#bai ,camper denies that the animal is carnivorous1 because the incisores1 or canine teeth1 are wanting2 and he argues farther1 from the weight of the head1 which may be inferred from the weight of the grinders1 that the neck must have been short1 and the animal must have been furnished with a proboscis4 ,he afterwards abandoned the latter hypothesis1 and gave it as his opinion that the incognitum was neither carnivorous1 nor a species of the elephant4#bbj ,footnote #bai3 ,acta ,acad4 ,petrop4 tom4 i4 7#aggg17 pars posterior1 p4 #bac1 c4 ,footnote #bbj3 ,ibid4 tom4 ii4 7#aghd17 p4 #bfb4 #daa4 ,nevertheless1 ,,cuvier1 in a mmoire read before the ,national ,institute of ,paris1 maintains1 that the fossil bones of the new ,continent1 as well as most of those of the old1 belong to certain species of the elephant2 of which1 at least1 two do not now exist1 and are only known from remains preserved in the ground4 ,he distinguishes them thus3#bba ,footnote #bba3 ,mmoires de l',institut ,national1 ,sciences ,physiques1 tom4 ii4 p4 #ai1 c4 ,elephas mammonteus1--maxill obtusiore1 lamellis molarium tenuibus1 rectis4 ,elephas ,americanus1--molarities multicuspidibus1 lamellis post detritionem quadric-lobatis4 ,the latter species1 which is meant to include the animal incognitum1 is said to have lived1 not only in ,america1 but in many parts of the old ,continent4 ,yet some late inquiries into the structure of the teeth of graminivorous animals1 and particularly of the elephant1 make it very improbable that the incognitum has belonged to this genus4#bbb ,the grinders of the elephant have been found to consist of three substances1 enamel1 bone1 and what is called the crusta petrosa1 applied in layers1 or folds contiguous to one another2 and no vestige of this structure appears in the grinders of the unknown animal of the ,ohio4#bbc ,at the same time1 ,dr ,hunter's assertion1 that this animal was carnivorous1 is rendered doubtful1 not only by the want of canine teeth1 but also from the resemblance between its grinders and those of the wild boar1 which ,mr ,home has observed to be considerable4#bbd ,the grinder of the boar is similar to that of the elephant1 in the extent of the masticating surface1 but not at all in the internal structure2 and the same is true of the tooth of the animal incognitum1 so that a considerable probability is established1 that it and the boar are of the same genus1 and both destined to live occasionally either on animal or vegetable food4 ,footnote #bbb3 ,see ,mr ,home's ,observations on the ,teeth of ,graminivorous ,animals1 ,phil4 ,trans4 #agii4 ,also1 an ,essay on the ,structure of the ,teeth1 by ,dr ,blake4 ,footnote #bbc3 ,in a paper inserted in the fourth volume of the ,american ,philosophical ,transactions1 an account is given of two different grinders that are found at the ,salt ,licks near the ,ohio4 ,one of them resembles the grinder of the elephant1 and may have belonged to the ,elephas ,americanus of ,cuvier2 the other agrees pretty nearly with the grinder of ,dr ,hunter's animal incognitum4 ,the author of the paper thinks that the animal incognitum was not wholly carnivorous1 as the incisores1 or canine teeth1 are never found4 ,at the ,great ,bone ,lick1 bones of smaller animals1 particularly of the buffalo kind1 have been discovered4 ,the saline impregnation of the earth at these ,licks must no doubt have contributed to the preservation of the bones4 ,trans4 ,american ,phil4 ,soc4 vol4 iv4 7#agii17 p4 #eaj1 c4 ,footnote #bbd3 ,observations on the ,grinding ,teeth of the wild boar and animal incognitum4 ,phil4 ,trans4 #ahja1 p4 #cai4 #dab4 ,another animal incognitum found in ,south ,america has been described by ,cuvier1 and appears to be of a different genus from the incognitum of the ,north4 ,thus1 if we include the two incognita of ,america1 the elephas mammonteus1 the unknown buffalo of ,pallas1 and the great animal of ,bayreuth1 we have at least five distinct genera1 or species of the animal kingdom1 which existed on our continents formerly1 but do not exist on them now4 ,the number is probably much greater3 ,pallas mentions fossil horns of a gazelle1 of an unknown species2 and horns of deer are often found1 that cannot be referred to any species now existing4 ,those extinct races have been remarkable for their size3 some of the ancient elephants appear to have been three times as large as any of the present4#bbe ,footnote #bbe3 ,camper1 ,nov4 ,acta ,petrop4 tom4 ii4 7#aghd7 p4 #beg4 #dac4 ,the inhabitants of the globe1 then1 like all the other parts of it1 are subject to change4 ,it is not only the individual that perishes1 but whole species1 and even perhaps genera1 are extinguished4 ,it is not unnatural to consider some part of this change as the operation of man4 ,the extension of his power would necessary subvert the balance that had before been established between the inhabitants of the earth1 and the means of their subsistence4 ,some of the larger and fiercer animals might indeed dispute with him1 for a long time1 the empire of the globe2 and it may have required the arm of a ,hercules to subdue the monsters which lurked in the caves of ,bayreuth1 or roamed on the banks of the ,ohio4 ,but these1 with others of the same character1 were at length exterminated3 the more innocent species fled to a distance from man2 and being forced to retire into the most inaccessible parts1 where their food was scanty1 and their migration checked1 they may have degenerated from1 the size and strength of their ancestors1 and some species may have been entirely extinguished4 ,but besides this1 a change in the animal kingdom seems to be a part of the order of nature1 and is visible in instances to which human power cannot have extended4 ,if we look to the most ancient inhabitants of the globe1 of which the remains are preserved in the strata themselves1 we find in the shells and corals of a former world hardly any that resemble exactly those which exist in the present4 ,the species1 except in a few instances1 ate the same1 but subject to great varieties4 ,the vegetable impressions on slate1 and other argillaceous stones1 can seldom be exactly recognised2 and even the insects included in amber are different from those of the countries in which the amber is found4 #dad4 ,supposing1 then1 the changes which have taken place in the qualities and habits of the animal creation1 to be as great as those in their structure and external form1 we can have no reason to wonder if it should appear that some have formerly dwelt in countries from which the similar races are now entirely banished4 ,the power of living in a different climate1 of enduring greater degrees of cold or of heat1 or of subsisting on different kinds of food1 may very well have accompanied the other changes4 ,though one species of elephant may now be confined to the southern parts of ,asia1 another may have been able to endure the severer climates of the north2 and the same may be true of the buffalo or the rhinoceros4 ,in all this no physical impossibility is involved2 though whether it is a probable solution of the difficulty concerning the origin of these animal remains1 can only be judged of from other circumstances4 #dae4 ,if we consider attentively the facts that respect the ,siberian fossil bones1 there will appear insurmountable objections to every theory that supposes them to be exotic1 and to have been brought into their present situation from a distant country4 ,the extent of the tract through which these bones are scattered1 is a circumstance truly wonderful4 ,pallas assures us1#bbf that there is not a river of considerable size in all the north of ,asia1 from the ,tanais1 which runs into the ,black ,sea1 to the ,anadyr1 which falls into the ,gulf of ,kamtchatka1 in the sides or bottom of which bones of elephants and other large animals have not been found4 ,this is especially the case where the rivers run in plains through gravel1 sand1 clay1 c42 among the mountains1 the bones are rarely discovered4 ,the extent of the tract just mentioned exceeds four thousand miles2 and how the bones could be distributed over all that extent1 by any means but by the animals having lived there1 it seems impossible to conceive4 ,no torrent nor inundation could have produced this effect1 nor could the bones brought in that way have been laid together so as to form complete skeletons4 ,footnote #bbf3 ,de ,reliquiis ,animalium exoticorum1 per ,asiam ,borealem repertis4--,nov4 ,comment ,petrop4 tom4 xvii4 7#aggb17 p4 #egf4 #daf4 ,one fact recorded by the same author1 seems calculated to remove all uncertainty4 ,it is that of the carcase of a rhinoceros1 almost entire1 and covered with the hide1 found in the earth in the banks of the river ,wilui1 which falls into the ,lena below ,jakutsk4#bbg ,some of the muscles and tendons were actually adhering to the head when ,pallas received it4 ,the head1 after being dried in an oven1 is still preserved in the museum at ,petersburgh4 ,the preservation of the skin and muscles of this natural mummy1 as ,pallas calls it1 was no doubt brought about by its being buried in earth that was in a state of perpetual congelation2 for the place is in the parallel of #fd1 where the ground is never thawed but to a very small depth below the surface4 ,footnote #bbg3 ,pallas ubi supra1 p4 #ehf4 ,also1 ,voyages de ,pallas1 tom4 iv4 p4 #aca4 ,but by what means can we account for the carcase of a rhinoceros being buried in the earth1 on the confines of the polar circle8 ,shall we ascribe it to some immense torrent1 which1 sweeping across the deserts of ,tartary1 and the mountains of ,altai1 transported the productions of ,india to the plains of ,siberia1 and interred in the mud of the ,lena the animals that had fed on the banks of the ,barampooter or the ,ganges8 ,were all other objections to so extraordinary a supposition removed1 the preservation of the hide and muscles of a dead animal1 and the adhesion of the parts1 while it was dragged for #bjjj miles over some of the highest and most rugged mountains in the world1 is too absurd to be for a moment admitted4 ,or shall we suppose that this carcase has been floated in by an inundation of the sea1 from some tropical country now swallowed up1 and of which the numerous islands of the ,indian ,archipelago are the remains8 ,the heat of a tropical climate1 and the putrescence naturally arising from it1 would soon1 independently of all other accidents1 have stripped the bones of their covering4 ,indeed this instantia singularis1 as in every sense it may properly be called1 seems calculated for the express purpose of excluding every hypothesis but one from being employed to explain the origin of fossil bones4 ,it not only excludes the two which have just been mentioned1 but it excludes also that of ,buffon1 viz4 that these bones are the remains of animals which lived in ,siberia1 when the arctic regions enjoyed a fine climate1 and a temperature like that which southern ,asia now possesses4 ,from the preservation of the flesh and hide of this rhinoceros1 it is plain1 that when the body was buried in the earth1 the climate was much the same that it is now1 and the cold sufficient to resist the progress of putrefaction4 ,pallas takes notice of the inconsistency of the state of this skeleton1 with the hypothesis of ,buffon2 but he does not observe that the inconsistency is equally great between it and his own hypothesis1 the importation of the fossil bones by an inundation of the sea1 and that flesh or muscle must have been entirely consumed long before it could be carried by the waves to the parallel of #fd1 from any climate which the rhinoceros at present inhabits4 #dag4 ,the presence of petrified marine objects in places where some of the fossil bones are found1 is no proof that the latter have come from the sea1 though it is produced as such both by ,pallas himself1 and afterwards by ,kirwan4 ,these marine bodies are the shells and corals that have been parts of calcareous rocks1 from which being detached by the ordinary progress of disintegration1 they are now contained in the beds of sand or gravel where the animal remains are buried4 ,they have nothing in common with these remains2 they are real stones1 and belong to another1 and a far more remote epochs4 ,such objects being found in the same place where the bones lie1 argues only that the strata in the higher grounds1 from which the gravel has come1 are calcareous2 and nothing can show in a stronger light the necessity of distinguishing the different condition of fossil bodies1 united by the mere circumstance of contiguity1 before we draw any inference as to their having a common origin4 ,if the marine remains were in the same condition with the bones2 if they were in no respect mineralized2 then the conclusion1 that both had been imported by the sea1 would have great probability2 but without that1 their present union must be held as casual1 and can give no insight into the origin of either4 #dah4 ,on the whole1 therefore1 no conclusion remains1 but that these bones have belonged to species of elephants1 rhinoceros1 c4 which inhabited the very countries where their remains are now buried1 and which could endure the severity of the ,siberian climate4 ,the rhinoceros of the ,wilui certainly lived on the confines of the ,polar ,circle1 and was exposed to the same cold while alive1 by which1 when dead1 its body has been so long1 and so curiously preserved4 ,these animals may also have lived occasionally farther to the south1 among the valleys between the great ranges of mountains that bound ,siberia on that side4 ,fossil bones are but rarely found in these valleys1 probably because they have been washed down from thence into the plains4 ,we must observe1 too1 that those animals may have migrated with the seasons1 and by that means avoided the rigorous winter of the high latitudes4 ,the dominion of man1 by rendering such migration to the larger animals difficult or impossible1 must have greatly changed the economy of all those tribes1 and narrowed the circle of their enjoyments and existence4 ,the heaps in which the fossil bones appear to be accumulated in particular places1 especially in ,north ,america1 have a great appearance of being connected with the migrations of animals1 and the accidents that might bring multitudes of them into the same spot4 ,what holds of ,siberia and of ,north ,america1 is applicable1 a fortiori1 to all the other places where animal remains are found in the same condition4 ,thus we are carried back to a time when many larger species of animals1 now entirely extinct1 inhabited the earth1 and when varieties of those that are at present confined to particular situations1 were1 either by the liberty of migration1 or by their natural constitution1 accommodated to all the diversities of climate4 ,this period1 though beyond the limits of ordinary chronology1 is posterior to the great revolutions on the earth's surface1 and the latest among geological epochs4 ,,note ,,xxiii4 #abh4 ,geology of ,,kirwan and ,,de ,,luc4 #dai4 ,the two champions of the ,neptunian system1 who have distinguished themselves most by their hostility to ,dr ,,hutton1 are ,,de ,,luc and ,,kirwan4 ,they have carried on their attack nearly on the same plan1 and have employed against their antagonist the weapons both of theology and science4 ,with a spirit as injurious to the dignity of religion1 as to the freedom of philosophical inquiry1 they have disregarded a maxim enforced by the authority of ,bacon1 and by all our experience of the past2 ,tanto magis hc vanitas inhibenda venit et corcenda1 quia1 ex divinorum et humanorum male-sana admixtione1 non solum educitur philosophia phantastica1 sed etiam religio hretica4 ,itaque salutare admodum est1 si mente sobri1 fidei tantum dentur qu fidei sunt4#bbh ,footnote #bbh3 ,the whole passage is deserving of attention1 and it seems as if the prophetic spirit of ,bacon had addressed it to the cosmologists of the present day4 ,pessima enim res errorem ,,apotheosis1 et pro peste intellects habenda est1 si vanis accedat veneratio4 ,huic autan vanitati nonnulli ex modernis summ levitate ita indulserunt1 ut1 in primo capitolo ,,geneseos1 et aliis ,scripturis ,sacris1 philosophiam naturalem fundari conati sunt3 ,inter ,,viva qurentes ,,mortua4--,nov4 ,organum1 lib4 i4 aphor4 #fe ,proceeding1 accordingly1 in direct opposition to rules that1 have never yet been violated with impunity1 and mistaking the true object of a theory of the earth1 they carry back their inquiries to a period prior to the present series of causes and effects1 where1 having neither experience nor analogy to direct them1 they pretend to be guided by a superior light4 ,they would have us to consider their geological speculations as a commentary on the text of ,,moses2 they endeavour to explain the action of creative power1 and1 with indiscreet curiosity1 would tear off the veil which the hand of the prophet has so wisely respected4 ,but the veil cannot be torn off1 and all that is behind it must be to man as that which never has existed4 #dbj4 ,m4 ,de ,luc has nevertheless treated very diffusely of the history of the solar system1 previous to the establishment of the present laws of nature1 and has dwelt on it with great complacency1 and singular minuteness of detail4 ,his tenth letter to ,,la ,,metherie has the following title3 ,on the ,history of the ,earth1 from the time when that planet was penetrated by light1 till the appearance of the sun2 a portion of time which includes the origin of heat1 and of the figure of the earth2 of its primeval strata1 of the ancient sea1 of our continents1 as the bottom of that sea1 of the great chains of mountains1 and of vegetation4#bbi ,footnote #bbi3 ,journal de ,physique1 tom4 #cg4 7#agij17 partie #b;de1 p4 #ccb4 ,as ,i may not have done justice to this extraordinary title1 it may be right to present it in the original4 ,sur l',histoire de la ,,terre1 depuis que cette planette fut penetre de ,,lumiere1 jusqu' l'apparition du ,,soleil2 espace de tems qui renferme les ,,origines de la chaleur1 et de la figure de notre globe2 de ses couches primordiales1 de l'ancienne mer1 de nos continens1 comme fond de cette mer1 de leurs grandes chanes de montagnes1 et de la vegetation4 ,i must confess that ,i am unacquainted with every thing of this letter but the title2 and could not easily be prevailed on to follow any man who professedly goes out of nature in search of knowledge2 who pretends to give the history of our planetary system when there was no sun1 and to enumerate the events which took place between the existence of that luminary1 and the existence of light4 ,the absurdity of such an undertaking admits of no apology2 and the smile which it might excite1 if addressed merely to the fancy1 gives place to indignation when it assumes the air of philosophic investigation4 #dba4 ,it sets1 however1 in a strong light1 the inconsistencies that may be observed in the intellectual character of the same individual1 to consider that the author of this strange and inconsistent reverie1 is1 nevertheless1 an excellent observer1 and well skilled in experimental inquiries4 ,it will hardly be believed that he who writes the history of the earth before the formation of the sun1 is versed in the principles of inductive reasoning2 and that he has added much to the stock of geological knowledge1 having observed accurately1 and described with great perspicuity and candour4 ,his ,lettres ,physiques are full of valuable and just observations1 though accompanied with reasonings that do not seem always entitled to the same praise2 and in another work he has succeeded where many men of genius had failed1 and has made considerable improvements in a branch of the mathematics1 without borrowing almost any assistance from the principles of that science4#bcj ,footnote #bcj3 ,essai sur les ,modifications de l',atmosphere4 #dbb4 ,some of the same observations apply to ,mr ,kirwan4 ,his ,geological ,essays have also for their object to explain the first origin of things2 and to say that he has not succeeded1 in an attempt where no man ever can succeed1 implies no reproach on the execution of his work1 whatever it may do on the design4 ,we have indeed no criterion by which the execution of it can be estimated3 what would in any other place be a blemish1 may be here deserving of praise2 and if the work is full of confusion and perplexity1 these are qualities inherent in the subject which it is intended to describe4 ,it were1 no doubt1 to be wished1 that after emerging into the regions of day1 ,mr ,kirwan had been as successful in copying the beauty and simplicity of nature1 as in representing the disorder and inconsistency of the chaotic mass4 ,but his cosmology is without unity in its principles1 or consistency in its parts2 the causes introduced1 are1 for the most part1 such as will account for one set of appearances just as well as for another2 or1 if any of them is likely to prove inadequate to the effect ascribed to it1 a new and arbitrary hypothesis is always ready to come to its assistance4 ,the information given is seldom exact3 a multitude of facts brought together1 without the order and discussion essential to precise knowledge2 and an infinity of quotations1 amassed without criticism or comparison1 afford proofs of extensive reading1 but of the most hasty and superficial inquiry4 ,thus we have seen passages from ,,ulloa and ,,frisi1 produced in support of opinions1 which1 when fairly stated1 they had the most direct tendency to overthrow4 #dbc4 ,in one respect1 the geological writings of ,kirwan are far inferior to ,de ,luc's3 ,they are evidently the productions of a man who has not seen nature with his own eyes2 who has studied mineralogy in cabinets1 or in books only2 but who has seldom beheld fossils in their native place4 ,with the balance in his hand1 and the external characters of ,,werner in his view1 he has examined minerals with diligence1 and has discovered many of those marks which serve to ascertain their places1 in a system of artificial arrangement4 ,but to reason and to arrange are very different occupations of the mind2 and a man may deserve praise as a mineralogist1 who is but ill qualified for the researches of geology4 #dbd4 ,the same hurry and impatience are visible in the manner in which his argument against ,dr ,hutton is usually conducted4 ,he has seldom been careful to make himself master of the opinions of his adversary2 and what he gives as such1 and directs his reasonings against1 have often no resemblance to them whatsoever4 ,without any intention to deceive others1 but deceived himself1 he usually begins with misrepresenting ,dr ,hutton's notions1 and then proceeds to the refutation of them4 ,in this imaginary contest1 it will readily be supposed1 that he is in general successful3 when a man has the framing both of his own argument1 and that of his antagonist1 he must be a very unskilful logician if he does not come off with the advantage4 #dbe4 ,it is but justice1 however1 to the ,neptunists1 to acknowledge1 that they are not all liable to the censure of beginning their researches from a period antecedent to the existence of the laws of nature4 ,this absurdity does not1 so far as ,i know1 infect the system of ,werner4 ,that mineralogist has not proposed to explain the first origin of things1 though he has supposed1 at some former period1 a condition of the globe very unlike the present1 viz4 the entire submersion of the solid under the fluid part4 ,,note ,,xxiv4 #abi4 ,system of ,,buffon4 #dbf4 ,the affinity of ,dr ,hutton's theory to that of ,buffon1 is nothing more than what arises from their making use of the same agents1 viz4 fire and water1 in producing the present condition of the earth's surface4 ,in almost all other respects the two theories are extremely different4 ,the order in which those agents are employed in them1 is directly opposite1 as has already been remarked2 ,buffon introducing the action of fire first1 and of water only in the second place1 to waste and destroy mineral bodies1 and afterwards to dispose them anew1 and arrange them into strata4 ,he makes no provision for the consolidation of these strata1 nor any for their angular elevation2 he has no means of explaining the unstratified rocks2 nor any1 but one extremely imperfect1 for explaining the inequalities of the earth's surface4 ,again1 ,buffon mistook1 in some degree1 the true object of a theory of the earth2 and though he did not go back1 like the geologists just named1 to a time when the laws of nature were not fully established1 he begins from a condition of things too unlike the present to be the basis of any rational speculation4 ,he does not1 indeed1 undertake to examine the state of our planetary system before the sun existed2 for from such extravagance1 even when most disposed to indulge his fancy1 he would surely have revolted4 ,but he treats of the world1 when the earth and the planets had just ceased to be a part of the sun1 and were newly detached from the body of that luminary4#bca ,footnote #bca3 ,according to ,buffon1 the granite is the true solar matter1 unchanged but by its congelation4 ,this hypothesis concerning the origin of the planets1 contrived chiefly to account for the circumstance of their motion being all in the same direction1 and in other respects not only unsupported1 but even inconsistent with the principle of gravitation1 has nothing in common with a theory1 confined as ,dr ,hutton's is1 within the field which must for ever bound our inquiries1 and not venturing to speculate about the earth1 when in a condition totally different from the present4 #dbg4 ,in what relates to the future1 the two systems are not more like than in what relates to the past ,buffon represents the cooling of our planet1 and its loss of heat1 as a process continually advancing1 and which has no limit1 but the final extinction of life and motion over all the surface1 and through all the interior1 of the earth4 ,the death of nature herself is the distant but gloomy object that terminates our view1 and reminds us of the wild fictions of the ,scandinavian mythology1 according to which1 annihilation is at last to extend its empire even to the gods4 ,this dismal and unphilosophic vision was unworthy of the genius of ,buffon1 and wonderfully ill suited to the elegance and extent of his understanding4 ,it forms a complete contrast to the theory of ,dr ,hutton1 where nothing is to be seen beyond the continuation of the present order2 where no latent seed of evil threatens final destruction to the whole2 and where the movements are so perfect1 that they can never terminate of themselves4 ,this is surely a view of the world more suited to the dignity of ,,nature1 and the wisdom of its ,,author1 than has yet been offered by any other system of cosmology4 #dbh4 ,i have often quoted ,buffon in1 the course of these ,illustrations1 and most commonly for the purpose of combating his opinions2 but ,i am very sensible1 nevertheless1 of the obligations under which he has laid all the sciences connected with the natural history of the earth4 ,the extent and variety of his knowledge1 the justness of his reasonings1 the greatness of his views1 his correct taste1 and manly eloquence1 qualified him1 better1 perhaps1 than any other individual1 to compose the ,history of ,nature4 ,the errors into which he ,has fallen1 are almost all the unavoidable consequences of the circumstances in which he was placed2 and if their amount is estimated by the proportion that they bear to the general excellence of the work1 they will be reckoned but of small account4 ,buffon began to write when many parts of natural history had made but little progress2 when the quantity of authentic information was small1 and when scientific and correct description was hardly to be found4 ,many of the greatest and most important facts in geology were quite unknown1 and scarcely any part of the mineral kingdom had been accurately surveyed2 and1 with such materials as this state of things afforded1 it is not wonderful if some parts of the edifice he erected have not proved so solid and durable as the rest4 ,had he appeared somewhat later2 had he been farther removed from the time when reasonings a priori usurped the place of induction2 and had he been as willing to correct the errors into which he had been betrayed by imperfect information1 as he was ingenious in defending them1 his work would probably have reached as great perfection1 as it is given for any thing without the sphere of the accurate sciences to attain4 ,if he had examined the natural history of the earth more with his own eyes1 and been as careful to delineate it with fidelity as force2 if he had listened with greater care to the philosophers around him2 had he attended to the demonstrations of ,,newton more1 and despised the arrangements of ,,linn,,us less2 he would have produced a work1 as singular for its truth as for its beauty1 and would have gone near to merit the eulogy pronounced by the enthusiasm of his countrymen1 ,,majestati ,,natur ,,par ,,ingenium4 ,,note ,,xxv4 #acj4 ,figure of the ,earth4 #dbi4 ,that the earth is a spheroidal body1 compressed at the poles1 or elevated at the equator1 is a fact established by many accurate experiments2 and though these experiments do not exactly coincide1 as to the degree of oblateness which they give to that spheroid1 they agree sufficiently to put it beyond all dispute1 that the earth1 though solid1 has nearly the same figure which it would assume if fluid1 in consequence of its rotation on its axis4 ,now1 it is not at all obvious1 to what physical cause this phenomenon is to be ascribed4 ,the earth1 as it exists at present1 has none of the conditions that render the assumption of the figure of equilibrium in any way necessary to it4 ,constituted as it is1 its parts cohere with forces incomparably too great to obey the laws of statical pressure1 or to assume any one figure rather than another1 on account of the centrifugal tendency which results from its revolution on its axis4 ,there is no necessity that its superficies should be every where level1 or perpendicular to the direction of gravity1 nor that every two columns1 standing on the same base1 any where within it1 and reaching from thence to any two points of the surface1 should be of such weights as precisely to balance one another4 ,neither of these1 indeed1 is at all conformable to fact4 ,they are1 however1 the very suppositions on which the determination of the spheroid of equilibrium is founded2 and as they certainly do in no degree belong to the earth1 it seems strange that the result deduced from them should be in any way applicable to it4 ,this coincidence remains1 therefore1 to be explained2 and it must greatly enhance the merit of any geological system1 if it can connect this great and enigmatical phenomenon with the other facts in the natural history of the earth4 #dcj4 ,to establish such a connection1 has1 accordingly1 been a favourite object with geologists1 whether they have embraced the ,neptunian or ,volcanic theory3 both have thought that they were entitled to suppose the primeval fluidity of the globe1 the one by water1 and the other by fire2 and in whatsoever way that fluidity was produced1 the result of it could be no other than the spheroidal figure of the whole mass1 agreeably to the laws of hydrostatics4 ,if in this fluid state the earth was homogeneous1 the spheroid would be accurately elliptical1 and the compression at the poles would be #a_/bcj of the radius of the equator2 if the fluid was denser toward the centre1 the flattening would be less3 and in either case1 the body1 as it acquired solidity1 may be supposed to have retained its spheroidal figure with little variation4 ,but though the fluidity of the earth will account for the phenomenon of its oblate figure1 it may reasonably be questioned1 whether this fluidity can be admitted1 in consistency with other appearances4 ,according to what is established above1 none of the appearances in the mineral kingdom indicate more than a partial fluidity in any former condition of the earth4 ,the present strata1 made up as they are of the ruins of former strata1 though softened by heat1 have not been rendered fluid by it1 and have even possessed their softness in parts1 and in succession1 not altogether1 nor at the same time4 ,the unstratified1 and more crystallized substances1 were cast in the bosom of others1 which were solid at the time when they were fluid4 ,in all this1 therefore1 there is no indication of a fluidity prevailing through the whole mass1 or even over the whole surface of the earth1 and therefore nothing that can explain the spheroidal figure which it has acquired4 ,the supposition1 then1 of the entire body of the earth1 or even of its external crust1 having been fluid1 though it might account for the compression at the poles1 does not connect that fact with the other facts in the natural history of the globe1 and fails1 therefore1 in the point most essential to a theory4 ,it is liable1 also1 to other objections1 whether it be conceived to have proceeded from fire or from water2 whether it has happened on the principles of ,buffon or of ,werner4 #dca4 ,first1 let us suppose that the fluidity of the earth1 or of the external crust of it1 at least to a certain depth1 proceeded from a solution of the whole in the waters of the ocean2 and1 waving all the objections that have been stated to this hypothesis1 on account of the absolute insolubility of many mineral substances in water1 let us suppose them all soluble in a certain degree1 and let us compute the quantity of the menstruum1 which1 on the suppositions most favourable to the system1 must have been required to this great geologico-chemical operation4 ,the siliceous earth1 though not soluble in water per se1 yet1 after being dissolved in that fluid by means of an alkali1 was found by ,dr ,black1 in his analysis of the ,geyser water1 to remain suspended in a quantity of water1 between #ejj and #ajjj times its own weight4 ,this is one of the facts most favourable to the ,neptunian theory2 and that every advantage may be given to that theory1 we shall take the least of the numbers just mentioned1 and suppose that siliceous earth may be dissolved or suspended in #ejj times its weight of water4 ,taking this for the extreme degree of insolubility of mineral substances1 7though there are many of which the insolubility is absolute1 or1 to speak in the language of calculation1 infinitely great17 we may suppose the insolubility of all the rest1 or the quantities of water in which they are dissolved1 to be ranged in a descending scale from #ejj to #j1 the extreme degree of deliquescence4 ,then1 taking the arithmetical mean between these extremes1 it will give us #bej1 as the proportion of water in which mineral substances may at an average be dissolved4 ,but this average is much less than the truth2 for the quantity of siliceous earth is great in comparison of any of the rest1 and the mineral substances that are extremely soluble in water are but in a small quantity2 therefore1 when we suppose mineral bodies1 at a medium1 to be soluble in #bej times their own weight of water1 we make a supposition extremely favourable to the ,neptunian system4 #dcb4 ,this is the proportion between the weight of the solvent1 and of the substances held in solution3 to have the proportion of their bulks1 we may suppose the specific gravity of mineral bodies in general to be to that of water as #e to #b1 and then we have the ratio of bulks1 that of #bej #e to #b #a1 or of #fbe to #a4 ,it follows1 then1 that minerals in general cannot be supposed soluble in less than #fbe times their bulk of water4 #dcc4 ,again1 it must be allowed to the ,neptunists1 that the fluidity of the whole earth is not necessary to account for its assuming the spheroidal figure4 ,it is sufficient if the whole of that crust or shell of matter was fluid1 which is contained between the actual surface of the terrestrial spheroid1 and the surface of the sphere inscribed within it2 that is1 of the sphere which has for its diameter the polar axis of the earth4 ,the whole of the minerals which compose this shell1 must at least have been dissolved in water1 and have formed the chaotic mass of ,mr ,kirwan4 ,the volume of the water required for this was not less than #fbe times the bulk of the spheroidal shell that has just been mentioned4 ,but1 assuming the difference between the polar axis and the equatorial diameter to be #a_/cjj of the latter1 which is the supposition most agreeable to the phenomena1 it is easy to show that the magnitude of the above spheroidal shell1 or the difference between the solid content of the earth1 and the sphere inscribed in it1 is greater than #a_/aea and less than #a_/aej of the whole earth2 so that the earth is less than #aea times the spheroidal shell4 ,the volume of the water1 therefore1 necessary to hold in solution the materials of this shell1 is to the volume of the whole earth as #fbe to #aea1 or in a greater ratio than that of four to one3 and such1 therefore1 at the very least1 is the quantity of water which ,mr ,kirwan supposes1 after it ceased to act in its chemical capacity1 to have retired into caverns in the interior of the earth4 ,thus the ,neptunists1 in their account of the spheroidal figure of the earth1 are reduced to a cruel dilemma1 and are forced to choose between a physical and a mathematical impossibility4 ,if we would inquire whether the opinion of the igneous origin of minerals1 as commonly received by the ,vulcanists1 is capable of affording a better solution of this difficulty1 the theory of ,m4 de ,buffon is the first that presents itself4 #dcd4 ,that philosopher considers the existence of the spheroidal figure as a proof that the whole of the earth must have been originally fluid2 and as the fluidity of the whole can only be ascribed to fusion1 he has supposed that the earth was originally a mass of melted matter struck off from the sun by the collision of a comet2 and that this mass1 when made to revolve on its axis1 put on a spheroidal figure1 which it has retained1 though now cooled down to congelation4 ,this system need not be considered in detail2 the foundation of it is laid in such defiance of the principles of geometry and mechanics1 that the architect1 notwithstanding all the fertility of his invention1 and all the resources of his genius1 was never able to give any solidity to the structure4 ,but it will be said1 that we may take a part of the system1 without venturing on the whole1 and may suppose that the earth1 or at least the external crust of it1 has been fluid by fire1 though we do not inquire into the cause of this fire1 or into the manner in which it was produced4 ,it is indeed true1 that1 when this is done1 we have not the same sort of absurdity to encounter that we met with in the ,neptunian system1 and that the ,volcanic theory does not1 like it1 come into direct collision with an axiom of geometry4 ,there are1 nevertheless1 great objections to it2 for though all the phenomena of the mineral kingdom attest a fluidity of igneous origin1 yet it is a fluidity that was never more than partial2 and though it has been over all the earth1 has been over it in succession only4 ,besides1 we are not entitled to assume the existence1 and again the disappearance of such a great quantity of heat1 without assigning some cause for the change4 #dce4 ,since1 then1 neither the hypothesis of the ,neptunists or the ,vulcanists1 affords any good explanation of the figure of the earth1 or such a one as can connect it with the other appearances in its natural history1 it remains to inquire1 whether the system that supposes a partial and successive fluidity1 like ,dr ,hutton's1 has any resource for explaining this great phenomenon4 ,of this subject ,dr ,hutton has not treated2 and when ,i was first made acquainted with his system1 it appeared to me a very serious objection to it1 that it did not profess to give an explanation of so important a fact as the oblate figure of the earth4 ,on considering the matter more closely1 however1 ,i found that there were principles contained in it from which a very satisfactory solution 7and1 ,i think1 the only satisfactory solution7 of that difficulty might be deduced4 ,this solution ,i shall endeavour to explain1 in as far1 at least1 as is necessary for the purpose of general illustration4 ,it is laid down in ,dr ,hutton's theory1 that the surface of the earth is perpetually changed by the detritus of the land2 and that from the materials thus afforded1 new horizontal strata are perpetually formed at the bottom of the sea4 ,if this be true1 and if the alternations of decay and renovation have been often repeated1 it is certain1 that the figure of the earth1 whatever it may have originally been1 must be brought at length to coincide with the spheroid of equilibrium4 #dcf4 ,here it is necessary to remark1 that the expressions1 figure of the earth1 and surface of the earth are each of them occasionally taken in two different senses4 ,the surface of the earth1 in its most obvious sense1 is that which bounds the whole earth1 and includes all its inequalities2 it is a surface extremely irregular1 rising to the tops of the mountains1 descending to the bottoms of the valleys1 and having the continuity of its curvature often interrupted1 or suddenly changed4 ,this may be called the actual surface1 and the figure bounded by it1 the actual figure1 of the earth4 ,the surface of the earth1 in another sense1 is one that is every where horizontal1 and is the same which water assumes when at rest4 ,this superficies is determined by the circumstance of its being constantly perpendicular to the direction of gravity2 it is the surface marked out by levelling1 and may be supposed to be continued from the sea1 through the interior of the land1 till it meet the sea again4 ,the figure bounded by this horizontal surface1 may properly be called the statical figure of the earth4 ,when it is said that the figure of the earth is an oblate spheroid1 it is the statical1 not the actual figure which is meant2 and the degrees of the meridian which astronomers measure1 are also referred to the superficies of the former4 #dcg4 ,suppose now a body like the earth1 but with its actual figure infinitely more irregular1 having a sea circumfused around it1 the water will descend into the lowest situations1 and will so arrange itself1 that its surface shall be perpendicular every where to the plumb-line1 or to the direction of gravity1 in which state only it can remain at rest4 ,the figure of the superficies which the sea must thus take will be of a continuous curvature1 and will return into itself2 though it may1 if the actual figure is very irregular1 be far either from a sphere or a spheroid4 ,if1 however1 we suppose the solid parts of this mass subject to be dissolved or worn away1 and carried down to the ocean1 there will be a tendency to give to the whole body the same figure that it would have assumed1 if it had been entirely fluid1 and subject to the laws of hydrostatics4 ,this tendency is the result of two principles4 #dch4 ,let us suppose the body just described to have no rotation1 so that the particles of it are actuated only by the forces of cohesion and of attraction4 ,it is then clear1 that every particle taken away by attrition from the parts above the level of the sea1 and deposited under the surface of it1 makes the general figure more compact1 bringing the remoter parts nearer to the centre of gravity of the whole2 so that1 in time1 if the body is homogeneous1 all the points of the surface will become equally distant from that centre4 ,thus the actual figure changes continually1 and approaches nearer to the statical4 ,while this change is going forward in the actual figure1 there is another produced on the statical1 that tends very much to accelerate the final coincidence1 of the two4 ,the effect of the inequalities of the land1 that rise above the horizontal surface1 is1 by their attraction1 to render the parts of that surface immediately under them1 more convex1 cteris paribus1 than the rest4 ,again1 where there are parts of extraordinary depth in the sea1 that is1 where the solid and denser parts are far removed from the surface of the ocean1 the curvature of the superficies of the sea is thereby diminished1 and that superficies is rendered less convex than it would be if the sea were shallower4 ,these propositions are both capable of strict mathematical demonstration4 ,hence the taking away of any particle of matter from the top of a mountain tends to diminish the curvature of the horizontal surface under the mountain1 where it is greatest2 and the deposition of the same particle at the bottom of the sea1 tends to increase the curvature of this superficies where it is least4 ,the general tendency1 therefore1 being to increase the curvature where it is least1 and to diminish it where it is greatest1 must be to bring about an uniform curvature throughout1 that is1 a spherical figure4 ,thus1 by the waste and subsequent stratification of the land1 the direction of gravity is continually altered2 it is more and more concentrated1 and the figure brought nearer to that which a fluid would assume4 #dci4 ,if now we suppose the body to revolve on its axis1 all other things remaining as before1 the surface bounding the sea will become different from what it was in the former case1 and will be more swelled out toward the middle or equatorial regions4 ,the land above the level of the sea will still1 as before1 be worn down and deposited in the bottom of the sea1 so as to form strata nearly parallel to its surface3 the tendency1 therefore1 is to render the real figure of the planet nearer to the statical4 ,at the same time the statical figure is changed1 as explained above2 so that the two figures mutually approach1 and the limit1 or ultimate figure to which they tend1 is one over which the ocean might be diffused every where to the same depth1 for then the causes of change would entirely cease4 ,but this figure is no other than the spheroid of equilibrium1 which1 therefore1 is the effect which the waste and reconsolidation of the land would necessarily produce1 if the process were continued indefinitely1 without interruption4 ,in this1 as in many other instances1 when a body is subject to the action of causes by which its form is gradually changed1 the figure best adapted to resist those changes1 is the figure which the changes themselves ultimately produce4 ,also1 whatever be the irregularities of density1 the tendency to a change of figure will not cease till the body is moulded into that particular spheroid which admits of being covered with water every where to the same depth4#bcb ,thus it appears1 that a solid of an irregular figure1 and of irregular density1 provided it be in part covered with water2 and be at the same time subject to waste above the surface of the sea1 and reconsolidation under it1 has a tendency to acquire1 in time1 the same figure that it would have acquired had it been entirely fluid4 ,footnote #bcb3 ,in the same manner as a transition is thus made from an irregular figure to a spheroid of equilibrium1 so1 if the actual figure were at first more simple than the spheroid1 it would still be changed into this last by degrees4 ,let us conceive1 for instance1 that the earth is at rest1 and is a perfect sphere of solid matter1 surrounded by an ocean every where of equal depth1 for example1 of one mile4 ,then1 if a rotatory motion be communicated to it1 so that it shall revolve on its axis in twenty-four hours1 in consequence of the centrifugal force1 the water circumfused about the sphere will immediately rise up under the equator1 and will become part of a spheroidal surface1 7not elliptical1 but nearly so17 the equatorial diameter of which is greater than the polar axis1 in the ratio of #ehh to #egg ,by this means the water will be accumulated at the equator to the depth of nearly #b4e miles1 and form a zone surrounding the earth1 and extending about #cg on each side of the equator4 ,the remainder of the surface will be left dry1 forming two vast circumpolar continents1 that reach #ec on every side of the poles1 and that are elevated in the middle more than four miles above the level of the sea4 ,such would be the state of our globe1 on the hypothesis above laid down2 and1 if there were no waste or destruction of the land1 this order of things would be permanent1 and neither the solid nor fluid part of the mass could ever acquire any other figure than that which has been described4 ,but1 if the same laws be supposed to regulate the action of the atmosphere in those circumstances1 that do actually regulate it according to the present constitution of the globe1 the vapours raised up from the surface of the sea1 would be carried by the winds over the land1 where they would be condensed and precipitated in rain4 ,thus1 all the agents of destruction would be let loose on the two great circumpolar continents2 rivers would be formed2 the land would become deeply intersected by ravines2 those ravines would gradually open into wide valleys2 the masses of greatest resistance would be shaped into hills and mountains3 and from a superficies originally smooth and uniform1 the same inequalities would be produced which at present diversify the surface of the earth4 ,while the parts of the sphere without the spheroid are thus continually diminished1 the loose earth and sand washed down from them1 will be deposited at the bottom of the sea1 and will form strata parallel to the surface of the superincumbent water4 ,the actual and statical figure are thus brought nearer one another2 and1 at the same time the statical is changed1 on the principle already explained1 7the change in the direction of gravity17 and is made continually to approximate to a state1 which when it has attained1 no farther change can take place1 viz4 an oblate elliptic spheroid1 of which the surface is perpendicular to the direction of gravity1 having the equatorial diameter to the polar axis in the ratio of #bcj to #bbi4 #ddj4 ,in the preceding reasonings1 we have supposed the process of decay and subsequent stratification to be carried on without interruption1 till the whole of the land is covered by the sea4 ,this supposition is useful for explaining the nature of the forces which have determined the figure of the earth2 but there is no reason to think that it has ever been realized in its full extent1 the elevation of strata from the bottom of the sea interrupting the progress1 and producing new land in one place1 as the old decays in another4 ,the very same land also1 which is wasted at its surface1 may perhaps be lifted up by the forces that are placed under it2 or it may be let down1 undergoing alterations of its level1 from causes that we do not perceive1 but of which the action is undoubted1 7 #chh47 ,but notwithstanding these interruptions1 the general tendency to produce in the earth a spheroidal figure may remain1 and more may be done by every revolution1 to bring about the attainment of that figure than to cause a deviation from it4 ,this figure1 therefore1 though never likely to be perfectly acquired1 will be the limiting or asymptotic figure1 if it may be so called1 to which the earth will continually approach4 #dda4 ,if the preceding conclusions are just1 and if the figure of equilibrium is only an asymptotic figure1 to which that of the earth may approximate1 but cannot perfectly attain1 we are not to be surprised if considerable deviations from it are actually observed4 ,this has accordingly happened1 insomuch1 that the results deduced from the most accurate measurement of degrees of the meridian1 differ from one another1 in the oblateness they give to the earth1 by nearly one half of the quantity to be determined4 ,when we compare the degrees measured in ,france1 and in some other countries of ,europe1 with those measured in ,peru1 we obtain for the compression at the poles1 less than #a_/cjj of the radius of the earth4 ,but when we compare the degrees measured in ,france with one another1 and with those lately measured in ,england1 we find that they are best represented by a spheroid that has its compression #a_/aej of its semi-axis4#bcc ,there is reason to think1 therefore1 that the meridians are not elliptical2 and other observations seem to show1 that they are not even similar to one another2 or that the earth is not1 strictly speaking1 a solid of revolution2 so1 also1 the comparison of the degree measured at the ,cape of ,good ,hope1 with those measured on the opposite side of the equator1 creates a suspicion1 that the northern and southern hemispheres are not perfectly alike1 and that the earth is not equally compressed at the ,arctic and the ,antarctic poles4 ,these irregularities1 though they do not affect the general fact of the earth's compression at the poles1 show that the true statical figure is but imperfectly attained2 and though this may be accounted for1 without having recourse to the principles involved in our theory1 it is in a manner very unsatisfactory1 and1 by help of suppositions1 not at all consistent with the original fluidity ascribed to the whole mass1 or to the exterior crust of the earth4 ,footnote #bcc3 ,exposition du ,systme du ,monde1 par ,la ,place1 p4 #fa1 #b;d edit4 #ddb4 ,as the principles here laid down explain how a solid body may attain very nearly the figure which a fluid would acquire in order to preserve its parts in equilibrium2 and since the oblate figure belongs to other of the planets as well as the earth1 and the globular to all the great bodies of the universe1 this suggests an analogy that goes deep into the economy of nature1 and extends far beyond the limits within which the mineralogist is wont to confine his speculations4 #ddc4 ,that no very irregular figure is found among the planetary bodies1 may therefore be considered as a proof of the universality of that system of waste and reconsolidation that we have been endeavouring to trace in the natural history of the earth4 ,a farther proof of the same arises from considering1 that for every given mass of matter1 having a given period of rotation1 there are two different spheroids that answer the conditions of establishing an equilibrium among its parts1 the one near to the sphere1 and the other very distant from it1 and so oblate as to have a lenticular form4 ,thus the earth1 supposing it homogeneous1 might either be in equilibrium1 by means of the figure which it actually has1 or of one in which the polar was to the equatorial diameter as #a to #gfh4 ,the same is true of the other planets2 and yet we no where find that this highly compressed spheroid is actually employed by nature4 ,the reason1 no doubt1 is1 that in so oblate a spheroid1 the equilibrium between the gravitating and the centrifugal force is of the kind that does not re-establish itself when disturbed2 so that the parts let loose1 and not kept in their place by firm cohesion1 would fly off altogether4 ,in such a body1 the waste at the surface would lead to an entire change of form1 and therefore the constitution here supposed could not be permanent4 #ddd4 ,in the system of ,saturn1 we have a great deviation from the general order1 which1 nevertheless1 has led to a very unexpected verification of some of the conclusions deduced above4 ,a principle extremely like that which is the basis of all the foregoing reasonings1 led one of the greatest philosophers of the present age to discover the revolution of ,saturn's ring on its axis1 and even to determine the velocity of that revolution1 such as it has been since found by observation4 ,,la ,,place1 laying it down as a maxim1 that nothing in nature can exist1 where there are causes of change1 not balanced or compensated by other causes1#bcd concluded1 that the-parts of the ring must be held from falling down to the body of the planet by some other force than their mere cohesion to one another4 ,were it otherwise1 every particle detached from the ring1 by any means1 must descend in a straight line1 almost perpendicular to the surface of ,saturn2 and the final destruction of the ring must be inevitable4 ,the only force that could balance this effect of gravitation1 seemed to be a centrifugal force1 arising from the rotation of the ring on an axis passing through its centre1 and perpendicular to its plane4 ,la ,place proceeded to inquire what celerity of rotation was adequate to this effect1 and found that one of ten hours and a quarter would be required1 which is almost precisely the time afterwards determined by ,dr ,,herschel from actual observation4 ,if1 with this rotation1 the ring is a solid annulus generated by the rotation of a very flat ellipsis about a given point in its greater axis1 coinciding with the centre of ,saturn1 it may be so constituted1 that the attraction of ,saturn1 combined with the centrifugal force1 may produce a force perpendicular to its surface1 and may enable detached parts to remain at rest1 animals1 for instance1 to walk on its surface1 and fluids to be in equilibrio4 ,the system of ,saturn is thus fortified against the lapse of time1 as effectually as that of the earth itself2 and the means by which this is accomplished1 seem to prove1 that the weapons which time employs1 are in both cases the same1 viz4 the slow wearing and decomposition of the solid parts4 ,this slow wearing may have produced the figure by which its action is most effectually resisted4 ,footnote #bcd3 ,la ,place1 ubi supra1 p4 #bdb4 #dde4 ,thus ,dr ,hutton's theory of the earth comes at last to connect itself with the researches of physical astronomy4 ,the conclusion to be drawn from this coincidence is to the credit of both sciences4 ,when two travellers1 who set out from points so distant as the mineralogist and the astronomer1 and who follow routes so different1 meet at the end of their journey1 and agree in their report of the countries through which they have passed1 it affords no slight presumption1 that they have kept the right way1 and that they relate what they have actually seen4 ,,note ,,xxvi4 #acc4 ,prejudices relating to the ,theory of the ,earth4 #ddf4 ,among the prejudices which a new theory of the earth has to overcome1 is an opinion1 held1 or affected to be held1 by many1 that geological science is not yet ripe for such elevated and difficult speculations4 ,they would1 therefore1 get rid of these speculations1 by moving the previous question1 and declaring that at present we ought to have no theory at all4 ,we are not yet1 they allege1 sufficiently acquainted with the phenomena of geology2 the subject is so various and extensive that our knowledge of it must for a long time1 perhaps for ever1 remain extremely imperfect4 ,and hence it is1 that the theories hitherto proposed have succeeded one another with so great rapidity1 hardly any of them having been able to last longer than the discovery of a new fact1 or a fact unknown when it was invented4 ,it has proved insufficient to connect this fact with the phenomena already known1 and has therefore been justly abandoned4 ,in this manner1 they say1 have passed away the theories of ,woodward1 ,burnet1 ,whiston1 and even of ,buffon2 and so will pass1 in their turn1 those of ,hutton and ,werner4 #ddg4 ,this unfavourable view of geology1 ought not1 however1 to be received without examination2 in science1 presumption is less hurtful than despair1 and inactivity is more dangerous than error4 ,one reason of the rapid succession of geological theories1 is the mistake that has been made as to their object1 and the folly of attempting to explain by them the first origin of things4 ,this mistake has led to fanciful speculations that had nothing but their novelty to recommend them1 and which1 when that charm had ceased1 were rejected as mere suppositions1 incapable of proof4 ,but if it is once settled1 that a theory of the earth ought to have no other aim but to discover the laws that regulate the changes on the surface1 or in the interior of the globe1 the subject is brought within the sphere either of observation or analogy2 and there is no reason to suppose1 that man1 who has numbered the stars1 and measured their forces1 shall ultimately prove unequal to this investigation4 #ddh4 ,again1 theories that have a rational object1 though they be false or imperfect in their principles1 are for the most part approximations to the truth1 suited to the information at the time when they were proposed4 ,they are steps1 therefore1 in the advancement of knowledge1 and are terms of a series that must end when the real laws of nature are discovered4 ,it is1 on this account1 rash to conclude1 that in the revolutions of science1 what has happened must continue to happen1 and because systems have changed rapidly in time past1 that they must necessarily do so in time to come4 ,he who would have reasoned so1 and who had seen the ancient physical systems1 at first all rivals to one another1 and then swallowed up by the ,aristotelian2 the ,aristotelian physics giving way to those of ,des ,cartes2 and the physics of ,des ,cartes to those of ,newton2 would have predicted that these last were also1 in their turn1 to give place to the philosophy of some later period4 ,this is1 however1 a conclusion that hardly any one will now be bold enough to maintain1 after a hundred years of the most scrupulous examination have done nothing but add to the evidence of the ,,newtonian ,,system4 ,it seems certain1 therefore1 that the rise and fall of theories in times past1 does not argue1 that the same will happen in the time that is to come4 #ddi4 ,the multifarious and extremely diversified object of geological researches1 does1 no doubt1 render the first steps difficult1 and may very well account for the instability hitherto observed in such theories2 but the very same thing gives reason for expecting a very high degree of certainty to be ultimately attained in these inquiries4 ,where the phenomena are few and simple1 there may be several different theories that will explain them in a manner equally satisfactory2 and in such cases1 the true and the false hypotheses are not easily distinguished from one another4 ,when1 on the other hand1 the phenomena are greatly varied1 the probability is1 that among them1 some of those instanti crucis will be found1 that exclude every hypothesis but one1 and reduce the explanation given to the highest degree of certainty4 ,it was thus1 when the phenomena of the heavens were but imperfectly known1 and were confined to a few general and simple facts1 that the ,philolaic could claim no preference to the ,ptolemaic system3 ,the former seemed a possible hypothesis2 but as it performed nothing that the other did not perform1 and was inconsistent with some of our most natural prejudices1 it had but few adherents4 ,the invention of the telescope1 and the use of more accurate instruments1 by multiplying and diversifying the facts1 established its credit2 and when not only the general laws1 but also the inequalities1 and disturbances of the planetary motions were understood1 all physical hypotheses vanished1 like phantoms1 before the philosophy of ,,newton4 ,hence the number1 the variety1 and even the complication of facts1 contribute ultimately to separate truth from falsehood2 and the same causes which1 in any case1 render the first attempts toward a theory difficult1 make the final success of such attempts just so much the more probable4 ,this maxim1 however1 though a general encouragement to the prosecution of geological inquiries1 does not amount to a proof that we are yet arrived at the period when those inquiries may safely assume the form of a theory4 ,but that we are arrived at such a period1 appears clear from other circumstances4 #dej4 ,it cannot be denied1 that a great multitude of facts1 respecting the mineral kingdom1 are now known with considerable precision2 and that the many diligent and skilful observers1 who have arisen in the course of the last thirty years1 have produced a great change in the state of geological knowledge4 ,it is unnecessary to enumerate them all2 ,,ferber1 ,,bergman1 ,,de ,,luc1 ,,saussure1 ,,dolomieu1 are those on whom ,dr ,hutton chiefly relied2 and it is on their observations and his own that his system is founded4 ,if it be said1 that only a small part of the earth's surface has yet been surveyed1 and described with such accuracy as is found in the writers just named1 it may be answered1 that the earth is constructed with such a degree of uniformity1 that a tract of no very large extent may afford instances of all the leading facts that we can ever observe in the mineral kingdom4 ,the variety of geological appearances which a traveller meets with1 is not at all in proportion to the extent of country he traverses2 and if he take in a portion of land sufficient to include primitive and secondary strata1 together with mountains1 rivers1 and plains1 and unstratified bodies in veins and in masses1 though it be not a very large part of the earth's surface1 he may find examples of all the most important facts in the history of fossils4 ,though the labours of mineralogists have embraced but a small part of the globe1 they may therefore have comprehended a very large proportion of the phenomena which it exhibits2 and hence a presumption arises1 that the outlines1 at least1 of geology have now been traced with tolerable truth1 and are not susceptible of great variation4 #dea4 ,when the phenomena of any class are in general ambiguous1 and admit of being explained by different or even opposite theories2 if few of those exclusive facts are known1 which admit but of one or a few solutions1 then we have no right to expect much from our endeavours to generalise1 except the knowledge of the points where our information is most deficient1 and to which our observations ought chiefly to be directed4 ,but that many of the exclusive and unambiguous instances are known1 in the natural history of the globe1 ,i think is evident from the reasoning in the foregoing pages1 where so many examples have occurred of appearances that give the most direct negative to the ,neptunian system1 and exclude it from the number of possible hypotheses1 by which the phenomena of geology can be explained4 ,the abundance of such instances is an infallible sign1 that the mass of knowledge is in that state of fermentation1 from which the true theory may be expected to emerge4 #deb4 ,another indication of the same kind1 is the near approach that even the most opposite theories make1 in some respects1 to one another4 ,there are so many points of contact between them1 that they appear to approximate to an ultimate state1 in which1 however unwillingly1 they must at last coincide4 ,that ultimate form1 too1 which all these theories have a tendency to put on1 if ,i am not deceived1 is no other than that of the ,huttonian theory4 #dec4 ,the first example ,i shall take from the system of ,saussure4 ,it is to be regretted1 that this excellent geologist has no where given us a complete account of his theory4 ,some of the leading principles of it are1 however1 unfolded in the course of his observations1 and enable us to form a notion of its general outline4 ,it was evidently far removed from the system of subterraneous heat1 and seems1 especially in the latter part of the author's life1 to have been very much accommodated to the prevailing system of ,,werner4 ,nevertheless1 with so little affinity between their general views1 ,saussure and ,hutton agree in that most important article which regards the elevation of the strata4 ,saussure plainly perceived the impossibility of the strata being formed in the vertical situations which so many of them now occupy2 and he takes great pains to demonstrate this impossibility1 from some facts that have been referred to above4 ,he also believed that this elevation had been given to strata that were originally level1 by a force directed upwards1 or by the refoulement of the beds1 not by their falling in1 as is the opinion of ,de ,luc and some other of the ,neptunists4 ,now1 whoever admits this principle1 and reasons on it consistently1 without being afraid to follow it through all its consequences1 must unavoidably come very close to the ,huttonian theory4 ,he must see1 that a power which1 acting from below1 produced this great effect can never have belonged to water1 unless rarefied into steam by the application of heat4 ,but if it be once admitted that heat resides in the mineral regions1 the great objection to ,dr ,hutton's system is removed2 and the theorist1 who was furnished with so active and so powerful an agent1 would be very unskilful in the management of his own resources1 if he did not employ it in the work of consolidating as well as in that of raising up the strata4 ,a little attention will show1 that it is qualified for both purposes2 though insuperable objections must1 no doubt1 offer themselves1 where the effects of compression are not understood4 ,we may safely conclude1 then1 that the accurate and ingenious ,geologist of ,geneva ought to have been a ,plutonist1 in order to give consistency to the principles which he had adopted1 and to make them coalesce as parts of one and the same system4 ,if he embraced an opposite opinion1 it probably was from feeling the force of those objections that arise from our discovering nothing in the bowels of the earth like the remains left by combustion1 or inflammation1 at its surface4 ,the secret by which these seeming contradictions are to be reconciled1 was unknown to this mineralogist1 and he has accordingly decided strongly against the action of fire1 even in the case of those unstratified substances that have the greatest affinity to volcanic lava4 #ded4 ,the theoretical conclusions of another accurate and skilful observer1 ,dolomieu1 furnish a still more remarkable example of a tendency to union between systems professedly hostile to one another4 ,this ingenious mineralogist1 observing the interposition of the basalt between stratified rocks1 so that it had not only regular beds of sandstone for its base1 but was also covered with beds of the same kind1 saw plainly that these appearances were inconsistent with the supposition of common volcanic explosions at the surface4 ,he therefore conceived1 that the volcanic eruption had happened at the bottom of the sea1 7the level of which1 in former ages1 had been much higher than at present17 and that the materials afterwards deposited on the lava1 had been in length of time consolidated into beds of stone4 ,it is evident1 that this notion of submarine volcanoes1 comes very near1 in many respects1 to ,dr ,hutton's explanation of the same appearances4 ,if the only thing to be accounted for were the phenomenon in question1 it cannot be denied that ,dolomieu's hypothesis would be perfectly sufficient2 but ,dr ,hutton1 to whom this phenomenon was familiar1 and who1 like ,dolomieu1 conceived the basalt to have been in fusion1 was convinced that the retreat of the sea was not a fact well attested by geological appearances1 and if admitted1 was inadequate to account for the facts usually explained by it4 ,he conceived1 therefore1 that such lava as the preceding had flowed not only at the bottom of the sea1 but in the bowels of the earth1 and having been forced up through the fissures of rocks already formed1 had heaved up some of these rocks1 and interposed itself between them4 ,this agrees with the other facts in the natural history both of the basaltes and the strata4 ,it is plain1 that1 in this1 there is a great approach of the two theories to one another3 both maintain the igneous origin of basaltes1 and its affinity to lava2 both acknowledge that this lava cannot have flowed at the surface1 and that the strata which cover it have been formed at the bottom of the sea4 ,they only differ as to the mode in which the submarine or subterraneous volcano produced its effect1 and that difference arises merely from the one geologist having generalized more than the other4 ,dolomieu sought to connect the basalt with the lavas that proceed from volcanic explosions at the surface2 ,dr ,hutton sought not only to connect these two appearances with one another1 but also with the other phenomena of mineralogy1 particularly with the veins of basaltes1 and the elevation of the strata4 #dee4 ,in another point1 the coincidence of ,dolomieu's opinions and ,dr ,hutton's is still more striking4 ,the former has remarked1 that many of the extinguished volcanoes are in granite countries1 and that1 nevertheless1 the lavas that they have erupted contain no granitic stones4 ,there must be1 therefore1 says he1 something under the granite1 and this last is not1 at least in all cases1 to be considered as the basis of the mineral kingdom1 or as the body on which all others rest4 ,in this system1 therefore1 granite is not always a primordial rock1 any more than in ,dr ,hutton's4 ,but ,dolomieu makes a still nearer advance to the ,huttonian theory2 for he supposes1 that under the solid and hard crust of the globe1 there is a sphere of melted stone1 from which this basaltic lava was thrown up4 ,the system of subterraneous heat is here adopted in its utmost extent1 and in that form which is considered as the most liable to objection1 viz4 the existence of it at the present moment1 in such a degree as to melt rocks1 and keep them in a state of fusion4 ,in this conclusion1 the two theories agree perfectly2 and if they do so1 it is only because the nature of things has forced them into union1 notwithstanding the dissimilitude of their fundamental principles4 ,this ought to be considered as a strong proof1 that the phenomena known to mineralogists are sufficient to justify the attempts to form a theory of the earth1 and are such as lead to the same conclusions1 where there was not only no previous concert1 but even a very marked opposition4 ,i have already observed1 that there is a greater tendency to agree among geological theories1 than among the authors of those theories4 #def4 ,another circumstance worthy of consideration is1 that in the search which the ,neptunists have made1 for facts most favourable to the aqueous formation of minerals1 we find hardly any of a kind that was unknown to the author of the system here explained4 ,the appearances on which ,,werner grounds his opinion with respect to basaltes1 and by which he would exclude the action of fire from any share in the formation of it1 are all comprehended in the alternation of that rock with beds1 or strata obviously of aqueous origin4 ,now these appearances were well known to ,dr ,hutton1 and are easily explained by his theory1 provided the effects of compression are admitted4 ,from this1 and the other circumstances just observed1 ,i am disposed to think1 that the great facts on which every geological system must depend1 are now known1 and that it is not too bold an anticipation to say1 that a theory of the earth1 which explains all the phenomena with which we are at present acquainted1 will be found to explain all those that remain to be discovered4 #deg4 ,the time indeed was1 and we are not yet far removed from it1 when one of the most important principles involved in ,dr ,hutton's theory was not only unknown1 but could not be discovered4 ,this was before the causticity produced in limestone by exposure to fire was understood1 and when it was not known that it arose from the expulsion of a certain aerial fluid1 which before was a component part of the stone4 ,it could not then be perceived1 that this aerial part might be retained by pressure1 even in spite of the action of fire1 and that in a region where great compression existed1 the absence of causticity was no proof that great heat had not been applied4 ,the discoveries of ,dr ,,black1 therefore1 mark an era1 before which men were not qualified to judge of the nature of the powers that had acted in the consolidation of mineral substances4 ,those discoveries were1 indeed1 destined to produce a memorable change in chemistry1 and in all the branches of knowledge allied to it2 and have been the foundation of that brilliant progress1 by which a collection of practical rules1 and of insulated facts1 has in a few years risen to the rank of a very perfect science4 ,but even before they had explained the nature of carbonic gas1 and its affinity to calcareous earth1 ,i am not sure but that ,dr ,hutton's theory was1 at least1 partly formed1 though it must certainly have remained1 even in his own opinion1 exposed to great difficulties4 ,his active and penetrating genius soon perceived1 in the experiments of his friend1 the solution of those difficulties1 and formed that happy combination of principles1 which has enabled him to explain the most enigmatical appearances in the natural history of the earth4 ,as we are not yet far removed from the time when our chemical knowledge was too imperfect to admit of a satisfactory explanation of the phenomena of mineralogy1 so it is not unlikely that we are approaching to other discoveries that are to throw new light on this science4 ,it would1 however1 be to argue strangely to say1 that we must wait till those discoveries are made before we begin any theoretical reasonings4 ,if this rule were followed1 we should not know where the imperfections of our science lay1 nor when the remedies were found out1 should we be in a condition to avail ourselves of them4 ,such conduct would not be caution1 but timidity1 and an excess of prudence fatal to all philosophical inquiry4 #deh4 ,the truth1 indeed1 is1 that in physical inquiries1 the work of theory and observation must go hand in hand1 and ought to be carried on at the same time1 more especially if the matter is very complicated1 for there the clue of theory is necessary to direct the observer4 ,though a man may begin to observe without any hypothesis1 he cannot continue long without seeing some general conclusion arise2 and to this nascent theory it is his business to attend1 because1 by seeking either to verify or to disprove it1 he is led to new experiments1 or new observations4 ,he is led also to the very experiments and observations that are of the greatest importance1 namely1 to those instanti crucis1 which are the criteria that naturally present themselves for the trial of every hypothesis4 ,he is conducted to the places where the transitions of nature are most perceptible1 and where the absence of former1 or the presence of new circumstances1 excludes the action of imaginary causes4 ,by this correction of his first opinion1 a new approximation is made to the truth2 and by the repetition of the same process1 certainty is finally obtained4 ,thus theory and observation mutually assist one another2 and the spirit of system1 against which there are so many and such just complaints1 appears1 nevertheless1 as the animating principle of inductive investigation4 ,the business of sound philosophy is not to extinguish this spirit1 but to restrain and direct its efforts4 #dei4 ,it is therefore hurtful to the progress of physical science to represent observation and theory as standing opposed to one another4 ,bergman has said1 ,observationes veras qum ingeniosissimas fictiones sequi prstat2 natur mysteria potius indagare qum divinare4 ,if it is meant by this merely to say1 that it is better to have facts without theory1 than theory without facts1 and that it is wiser to inquire into the secrets of nature1 than to guess at them1 the truth of the maxim will hardly be controverted4 ,but if we are to understand by it1 as some may perhaps have done1 that all theory is mere fiction1 and that the only alternative a philosopher has1 is to devote himself to the study of facts unconnected by theory1 or of theory unsupported by facts1 the maxim is as far from the truth1 as ,i am convinced it is from the real sense of ,bergman4 ,such an opposition between the business of the theorist and the observer1 can only occur when the speculations of the former are vague and indistinct1 and cannot be so embodied as to become visible to the latter4 ,but the philosopher who has ascended to his theory by a regular generalization of facts1 and who descends from it again by drawing such palpable conclusions as may be compared with experience1 furnishes the infallible means of distinguishing between perfect science and ingenious fiction4 ,of a geological theory that has stood this double test of the analytic and synthetic methods1 ,dr ,hutton has furnished us with an excellent instance1 in his explanation of granite4 ,the appearances which he observed in that stone led him to conclude1 that it had been melted1 and injected while fluid1 among the stratified rocks already formed4 ,he then considered1 that if this is true1 veins of granite must often run from the larger masses of that stone1 and penetrate the strata in various directions2 and this must be visible at those places where these different kinds of rock come into contact with one another4 ,this led him to search in ,arran and ,glentilt for the phenomena in question2 the result1 as we have seen1 afforded to his theory the fullest confirmation1 and to himself the high satisfaction which must ever accompany the success of candid and judicious inquiry4 #dfj4 ,it cannot1 however1 be denied1 that the impartiality of an observer may often be affected by system2 but this is a misfortune against which the want of theory is not always a complete security4 ,the partialities in favour of opinions are not more dangerous than the prejudices against them2 for such is the spirit of system1 and so naturally do all men's notions tend to reduce themselves into some regular form1 that the very belief that there can be no theory1 becomes a theory itself1 and may have no inconsiderable sway over the mind of an observer4 ,besides1 one man may have as much delight in pulling down1 as another has in building up1 and may choose to display his dexterity in the one occupation as well as in the other4 ,the want of theory1 then1 does not secure the candour of an observer1 and it may very much diminish his skill4 ,the discipline that seems best calculated to promote both1 is a thorough knowledge of the methods of inductive investigation2 an acquaintance with the history of physical discovery2 and the careful study of those sciences in which the rules of philosophising have been most successfully applied4 ,,finis4 99 99 99 99 99 ,transcriber ,note ,minor typos corrected4 ,some differences in application of accents and formatting were left as printed4