,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,small capitals have been converted to ,,solid capitals4 ,illustrations have been moved so they do not break up paragraphs4 ,deprecated spellings have been preserved4 ,typographical and punctuation errors have been silently corrected4 ,illustration3 ,a ,chemist's ,work ,bench4 ,,chemistry3 ,,developed ,,by ,,facts ,,and ,,principles ,,drawn ,,chiefly ,,from ,,the ,,non-,,metals1 ,,by ,,john ,,howard ,,appleton1 ,a4 ,m41 ,professor of ,chemistry in ,brown ,university4 ,,author ,,of 8,,the ,,young ,,chemist10 8,,qualitative ,,chemical ,,analysis10 8,,quantitative ,,chemical ,,analysis40 8,,the ,,laboratory ,,handbook40 ,,providence3 ,,providence ,,lithograph ,,company4 #ahhd4 ,,other ,,works ,,on ,,chemistry ,,by ,,professor ,,appleton3 ,i4 ,the ,young ,chemist3 ,a book of chemical experiments for beginners in ,chemistry4 ,it is composed almost entirely of experiments1 those being chosen that may be performed with very simple apparatus4 ,,ii4 ,qualitative ,analysis3 ,a brief but thorough manual for laboratory use4 ,it gives full explanations and many chemical equations4 ,the processes of analysis are clearly stated and the whole subject is handled in a manner that has been highly commended4 ,,iii4 ,quantitative ,analysis3 ,the treatment of the subject is such as to afford an acquaintance with the best methods of determining all the principal elements1 as well as with the most important type-processes both of gravimetric and volumetric analysis4 ,,the ,,explanations ,,are ,,direct ,,and ,,clear so that a pupil is enabled to work intelligently even without the constant guidance of the teacher4 ,by this means the book is adapted for self-instruction of teachers and others who require this kind of help to enable them to advance beyond their present attainments4 ,,iv4 ,the ,laboratory ,handbook3 ,an annual publication containing many convenient tables for laboratory use4 ,new tables are constantly introduced1 and changes are made in order to keep the matter abreast of the latest discoveries4 ,,copyright1 #ahhd1 ,,by ,,john ,,howard ,,appleton4 ,,printed ,,and ,,electrotyped ,,by ,e4 ,a4 ,,johnson ,,co41 ,,providence1 ,r4 ,i4 ,,preface4 ,this little book has been prepared as a popular introduction to the study of chemistry4 ,it is probably needless to recommend the subject3 chemistry is recognized as a science of such general interest1 such wide usefulness1 and such universal application1 that no intelligent person can endure long to remain ignorant of its principal facts and laws4 ,this book treats principally of the non-metals2 it is believed to be the verdict of authors and teachers of experience1 that these furnish the most suitable material for a beginner in the study of chemistry2 these best present the fundamental facts and principles of the science1 and they do it in connection with objects and phenomena easily accessible to almost every civilized human being4 ,the author contemplates the preparation hereafter of a book of similar general character1 only having its principal facts drawn from the chemistry of the metals4 ,in writing this book it has been the effort to treat the subject in a style that shall be attractive to the general reader2 but it is believed that in no case has scientific fact been sacrificed in the interest of popular form4 ,the arrangement of matter in the book is in accordance with the following plan3 ,after the introductory chapters1 which present the general principles of chemical action1 the chief non-metals are treated in a scientific order as follows3 the monads1 hydrogen1 chlorine1 bromine1 iodine1 and fluorine2 then the dyads1 oxygen and sulphur2 next the triads1 boron1 nitrogen2 finally the tetrads1 carbon and silicon2 thus including the four great groups into which the non-metals are naturally arranged4 ,the historical and biographical sketches1 that are distributed through the book1 have been introduced with the view of legitimately helping to retain the reader's attention4 ,most of the experiments described are such as may be performed by any one possessed of reasonable skill2 it is believed that they will afford profitable instruction as well as entertainment4 ,allusions to the applications of chemistry to the affairs of every-day life have been carefully introduced and have been developed as fully as the circumstances seem to warrant4 ,perhaps some comment upon the reading references 7pp4 #aj1 #ag1 #bd1 #bg1 #ca1 #ch1 #de1 #ef1 #gc1 #hd1 #ih1 #aaa1 #aaf1 #acc1 #aef1 #afa1 #ahf1 #aif1 #bad7 is proper4 ,they are largely from periodical publications1 and it is thought that they will be of service1 especially to mature students4 ,helps to reading are now viewed as among the most important offerings of teachers to learners4 ,the reading lists in this book point out some papers which are selected as being chiefly popular in style2 if these lead the reader to consult the others he will find himself introduced to some of the most important contributions to the knowledge of our science4 ,,brown ,,university1 ,august1 #ahhd4 ,,contents4 ,,chapter ,i4--,the scope of chemistry1 #g ,,chapter ,,ii4--,the elementary substances1 #ab ,,chapter ,,iii4--,names and symbols of elements1 #ai ,,chapter ,,iv4--,classification of the elementary substances2 metals and non-metals1 #bh ,,chapter ,v4--,compound substances2 examples of binary and ternary compounds1 #cb ,,chapter ,,vi4--,the construction of substances2 the mass1 the molecule1 the atom1 #ci ,,chapter ,,vii4--,how chemical affinity works2 the modern atomic theory1 #df ,,chapter ,,viii4--,hydrogen2 its discovery2 method of preparation2 its properties1 #eh ,,chapter ,,ix4--,balloons2 their invention and uses1 #gd ,,chapter ,x4--,chlorine2 its preparation and properties2 chlorohydric acid2 bleaching-powder1 #he ,,chapter ,,xi4--,bromine1 #ajj ,,chapter ,,xii4--,iodine1 #aje ,,chapter ,,xiii4--,fluorine1 #aab ,,chapter ,,xiv4--,oxygen2 its discovery2 its preparation2 its properties2 its relation to hydrogen2 the compound blowpipe2 its relation to combustion in general1 and to animal respiration1 #aag ,,chapter ,,xv4--,water1 its importance to living beings2 its terrestrial circulation2 its influence on climate1 #acd ,,chapter ,,xvi4--,sulphur2 sulphuretted hydrogen2 sulphur dioxide1 #adb ,,chapter ,,xvii4--,sulphur trioxide2 manufacture of sulphuric acid1 #aea ,,chapter ,,xviii4--,boron1 #aeg ,,chapter ,,xix4--,nitrogen2 its discovery2 its properties2 compound with hydrogen2 compounds with oxygen2 nitric acid1 #afb ,,chapter ,,xx4--,the ,atmosphere1 #agj ,,chapter ,,xxi4--,explosives2 gunpowder2 fireworks2 fulminates gun-cotton2 nitroglycerine1 #agg ,,chapter ,,xxii4--,phosphorus2 friction matches1 #ahg ,,chapter ,,xxiii4--,carbon2 charcoal2 lamp-black2 coal2 graphite2 the diamond2 other natural forms of carbon1 #aig ,,chapter ,,xxiv4--,compounds of carbon and oxygen1 #bae ,,chapter ,,xxv4--,illuminating gas1 #bba ,,chapter ,,xxvi4--,silicon1 #bbh ,,chemistry4 ,,chapter ,i4 ,,the ,,scope ,,of ,,chemistry4 ,chemistry treats of all kinds of material substances4 ,this is a very broad assertion1 but it appears to be true4 ,the solid rock matter of the earth and the wealth of living animal and vegetable substances upon it undergo all their varied changes in subjection to chemical laws4 ,the same is true of the water and of all liquid things we know2 and the declaration applies yet further to the invisible gaseous mass which surrounds and envelopes our terrestrial globe4 ,this deeper but thinner ocean which we call the atmosphere is also governed by chemical law in all its varied relations to the living beings as well as to the inanimate substances that have their existence within it4 ,in thought we may ascend above these solid1 liquid and gaseous substances connected with our earth4 ,when thus we reach out to the heavenly bodies beyond1 we feel sure that these1 possessing as they may1 solid1 liquid or gaseous matter1 are likewise controlled by chemical laws1 and that in their changes they exemplify with more or less fulness1 distinct chemical principles4 ,the ,great ,number of ,different ,substances in the ,earth4 ,here then it is intimated that chemistry relates to an enormous number of substances4 ,in fact the number of the various kinds of matter already existing on our earth is so great that they have never been so much as counted1 much less described1 in any list or volume2 nay more1 doubtless many exist that human beings have never recognized at all4 ,this last statement refers not merely to such substances as may be known only to savages dwelling beyond the reach of civilization and commerce1 nor yet to such as may be secreted in absolutely uninhabited portions of the globe1 nor even to those that exist so deep in the earth that man's power may never be sufficient to reach them4 ,probably even some of the most humble and familiar natural things1 such as blades of wheat1 petals of daisies1 silks of corn1 and the like1 contain small quantities of distinct and separate compounds that have not yet been recognized as such by even the most skillful chemists4 ,but even compounds such as are described in books on chemistry are exceedingly numerous2 and further1 the chemical laws now known suggest the possibility of producing artificially a great multitude of substances not yet recognized1 and even more than have yet been produced in the great laboratory of nature4 ,how it ,happens that there is such a ,variety4 ,by searching aright for the secret of the countless number and the rich and splendid variety of beings that nature and art present to the curious gaze of man1 a comprehensive answer is at last obtained4 ,forms of ordinary matter may be compared to great cathedrals1 like those of ,cologne and of ,milan1 which have been growing for centuries and which by the combined labor of artists and artisans have at length become intricate and beautiful structures1 the admiration and delight of the beholder4 ,just as these arise from the combination in a multitude of ways of a comparatively small number of original and fundamental substances--like stone1 brick1 iron1 copper1 plaster1 glass1 wood--so all things known to chemists are made up of a few simple substances1 either existing alone or in richly various combination4 ,the simplest substances when alone are called the chemical elements or elementary substances2 the things resulting when different elements are united together are called compounds4 ,thus metallic iron is one familiar example of a chemical element2 the oxygen gas of the atmosphere is another example4 ,a piece of iron exposed to damp air soon becomes changed to a mass of iron-rust4 ,this rust is a compound2 it is made up of iron and oxygen united together4 ,in the light of what has been said the chemical elements assume a new and grand importance3 they are the individuals chosen by the ,creator to be the foundation stones and the essential constituents of the glorious natural edifices of his handiwork4 ,again when the elementary individuals unite together they do so by reason of the interaction of many and complex forces which reside1 almost like soul and spirit1 within the elements4 ,these last remarks suggest the twofold character of chemical study4 ,it involves1 ,first1 the examination of elementary substances and their compounds4 ,secondly1 it requires a consideration of the many general and special laws and forces which determine the various possible combinations4 ,,reading ,,references4 ,in general1 the first-mentioned books in each group are those which are most accessible and at the same time most serviceable4 ,some rare and costly books are mentioned1 for the benefit of persons who have access to large libraries4 ,chemistry1 ,general and ,applied1 ,serial ,publications4 ,chemical ,news4 7,william ,crookes1 ,ed47 ,london4 ,weekly4 7,commenced #ahfj47 ,popular ,science ,news and ,boston ,journal of ,chemistry4 ,boston4 ,monthly4 7,commenced #ahfg47 ,journal of the ,chemical ,society4 ,london4 ,monthly4 -------- ,index to foregoing4 #ahda-ahgb3 pp4 #bfc4 ,annales de ,chimie et de ,physique4 ,paris4 ,monthly4 -------- ,table des ,tomes ,i ,,xxx4 7#ahda-ahea47 ,paris1 pp4 #acd4 -------- ,table ,analytique des ,tomes ,,xxxi ,,lxix4 #c;d ,series4 7#ahea-ahfc47 ,paris4 pp4 #dgd4 -------- ,table des ,noms d',auteurs et ,table ,analytique des ,matieres4 7#ahfd-ahgc47 #dth ,series4 ,paris4 pp4 #bdi4 ,berichte der ,deutschen ,chemischen ,gesellschaft4 ,berlin4 7,commenced #ahfh47 #bj parts per year4 ,wagner1 ,johannes ,r4 v4--,jahres-,bericht ber die ,fortschritte und ,leistungen der chemischen ,technologie4 ,leipzig4 ,annual4 7,commenced #ahee2 last vol4 had #a1ccb pp47 -------- ,index to foregoing4 ,vols4 ,i-,x4 -------- 0 0 ,vols4 ,x-,,xx4 ,dictionaries of ,chemistry1 etc4 ,watts1 ,henry4--,dictionary of ,chemistry and the allied branches of other sciences4 #h vols4 ,london4 #ahfe-ahge4 ,storer1 ,frank ,h4--,first ,outlines of a ,dictionary of ,solubilities of ,chemical ,substances4 ,cambridge4 #ahfd4 ,wurtz1 ,ad4--,dictionnaire de ,chimie1 pure et applique4 #c vols4 ,paris4 #ahgj4 ,fehling1 ,hermann v4--,neues ,handwrterbuch der ,chimie4 ,a to ,morphin4 ,braunschweig4 #ahga--now issuing4 ,general ,treatises on ,chemistry4 ,roscoe1 ,h4 ,e41 and ,schorlemmer1 ,c4--,a ,treatise on ,chemistry4 ,london and ,new ,york4 #ahgh4 ,vol4 ,i1 pp4 #gga2 ,vol4 ,,ii1 part ,i1 pp4 #ejd1 part ,,ii1 pp4 #eeb2 ,vol4 ,,iii1 part ,i1 pp #gbd4 7,now issuing47 ,cooke1 ,josiah ,p41 ,jr4--,principles of ,chemical ,philosophy4 ,boston4 #ahha4 ,gmelin1 ,leopold 7,henry ,watts1 ,tr47--,hand-,book of ,chemistry4 ,printed for the ,cavendish ,society4 #ad vols4 ,london4 #ahdh-ahfj4 ,graham-,otto's ,ausfhrliches ,lehrbuch der ,chemie4 #f vols4 ,braunschweig4 #aheg4 ,schtzenberger1 ,p4--,trait de ,chimie gnrale4 #c vols4 ,paris4 #ahhj4 ,,chapter ,,ii4 ,,the ,,elementary ,,substances4 ,on the following page is a list of the sixty-six elementary substances now generally recognized as such4 ,their respective symbols and their atomic weights1 both in exact and approximate numbers1 are also given4 ,these substances1 then1 nearly seventy in number1 are those from which are made up all material things now known to man4 ,while it is not necessary for any one to retain such a list in memory1 every person who desires any considerable knowledge of chemistry should be acquainted with each name and the symbol attached to it1 and should know something of the natural sources and the properties of the substances designated4 ,six ,suggestions ,conveyed by this ,table4 ,a careful and intelligent reading of the list affords several important suggestions4 ,the following are some of them3-- ,first4 ,the elements are not very numerous4 ,they are in fact very few1 as compared with the countless number of substances they may form by their proper combinations4 ,second4 ,they are however sufficiently numerous to produce the many substances recognized in nature4 ,for1 consider how human language may have many words and yet all these may be spelled out by combinations of few letters4 ,some ,english dictionaries register over a hundred thousand words1 yet these are all made by the combinations of less than thirty letters4 ,now it is easy to comprehend how the few letters of an alphabet may be even still further combined in various ways so as to produce additional words almost without limit3 in a similar manner it may be easily imagined that the sixty-five elementary substances have ample capabilities for giving rise not only to the compounds now known1 but to yet more and more1 almost without limit4 ,it is true that the chemist discovers that some of the chemical elements appear to have a limited power of union1 but in others he finds an apparently unbounded capacity to form new arrangements and combinations4 ---------------------------------------- --------------------------- ,the ,chemist's ,elementary ,substances4 ,name ,exact ,approximate of ,element4 ,atomic ,symbol4 ,atomic ,atomic ,weight4 ,weight4 ---------------------------------------- --------------------- ,aluminum ,al #bg4jjij #bg4 ,antimony ,sb 7,stibium7 #aai4ieej #abj4 ,arsenic ,as #gd4iahj #gd4i ,barium ,ba #acf4gfcj #acf4h ,bismuth ,bi #bjg4ebcj #bjg4e ,boron ,b #aj4idaj #aj4i ,bromine ,br #gi4gfhj #gi4h ,cadmium ,cd #aaa4hcej #aaa4h ,caesium ,cs #acb4ehcj #acb4f ,calcium ,ca #ci4iijj #dj4 ,carbon ,c #aa4igcf #ab4 ,cerium ,ce #adj4dbdj #adj4d ,chlorine ,cl #ce4cgjj #ce4d ,chromium ,cr #eb4jjij #eb4 ,cobalt ,co #eh4hhgj #eh4i ,copper ,cu 7,cuprum7 #fc4agcj #fc4b ,didymium ,d #add4egcj #add4f ,erbium ,e #afe4hiaj #afe4i ,fluorine ,fl #ah4ihdj #ai4 ,gallium ,ga #fh4hedj #fh4i ,glucinum ,g or ,be 7,beryllium7 #i4jhej #i4a ,gold ,au 7,aurum7 #aif4aeej #aif4b ,hydrogen ,h #a4jjjj #a4 ,indium ,in #aac4cihj #aac4d ,iodine ,i #abf4eegj #abf4f ,iridium ,ir #aib4feaj #aib4g ,iron ,fe 7,ferrum7 #ee4iacj #ee4i ,lanthanum ,la #ace4ebfj #ach4e ,lead ,pb 7,plumbum7 #bjf4dgaj #bjf4e ,lithium ,li #g4jjgc #g4 ,magnesium ,mg #bc4ieij #bd4 ,manganese ,mn #ec4ijfj #ec4i ,mercury ,hg 7,hydrargyrum7 #aii4gabj #aii4g ,molybdenum ,mo #ie4ebgj #ie4e ,nickel ,ni #eg4ibhj #eg4i ,niobium ,nb #ic4habj #ic4h ,nitrogen ,n #ad4jbaj #ad4 ,osmium ,os #aih4didj #aih4e ,oxygen ,o #ae4ifcc #af4 ,palladium ,pd #aje4gcgj #aje4g ,phosphorus ,p #cj4iehj #ca4 ,platinum ,pt #aid4daej #aid4d ,potassium ,k 7,kalium7 #ci4jaij #ci4 ,rhodium ,rh #ajd4jeej #ajd4a ,rubidium ,rb #he4beaj #he4c ,ruthenium ,ru #ajd4bagj #ajd4b ,scandium ,sc #dc4ihjj #dd4 ,selenium ,se #gh4gigj #gh4h ,silicon ,si #bh4aiej #bh4b ,silver ,ag 7,argentum7 #ajg4fgej #ajg4g ,sodium ,na 7,natrium7 #bb4iihj #bc4 ,strontium ,sr #hg4cgdj #hg4d ,sulphur ,s #ca4ihdj #cb4 ,tantalum ,ta #ahb4addj #ahb4a ,tellurium ,te #abg4ifjj #abh4 ,thallium ,tl #bjc4gaej #bjc4g ,thorium ,th #bcc4dadj #bcc4d ,tin ,sn 7,stannum7 #aag4fihj #aag4g ,titanium ,ti #dg4iiig #dh4 ,tungsten ,w 7,wolframium7 #ahc4fajj #ahc4f ,uranium ,u #bch4dhbj #bch4e ,vanadium ,va #ea4befj #ea4c ,ytterbium ,yb #agb4gfaj #agb4h ,yttrium ,y #hi4hafj #hi4h ,zinc ,zn #fd4ijde #fd4i ,zirconium ,zr #hi4cfgj #hi4d ---------------------------------------- ------------------------ ,third4 ,the elements are mostly uncommon4 ,only about one-sixth of them possess names that are familiar to ordinary readers4 ,thus carbon1 copper1 gold1 iron1 lead1 mercury1 nickel1 silver1 sulphur1 tin1 zinc1 are almost the only ones in the list that can be said to suggest familiar things4 ,indeed some members of this list exist in the earth in extremely small quantities2 but man by his ingenuity and industry has gathered up even these and brought them near to the hand of every civilized being4 ,thus gold exists in the earth--so far as man has access to the earth--in only very minute amounts2 yet gold has a multitude of common uses beside its employment in coinage4 ,various forms of decorative art1 like gilded lettering on books1 afford familiar examples4 ,so also mercury1 which in the ordinary thermometer is very familiar to every one1 exists in the earth in but minute amounts4 ,when the chemist examines still more narrowly the composition of the terrestrial globe1 he discovers an inequality yet more extraordinary than that hinted at4 ,thus it appears that probably one-half of our entire planet consists of a single substance 7that is1 oxygen7 and that one-quarter of it consists of another single substance 7that is1 silicon74 ,since an amount equal to three-quarters of the earth's matter1 by weight1 is made up of but two elements1 the remaining ones must necessarily exist in much smaller proportions4 ,the following table1 given by ,roscoe and ,schorlemmer1 shows the average composition of the earth's crust--so far as it is accessible to human investigation by means at present known3 ,percentage ,composition of the ,earth's ,solid ,crust 7by ,weight74 ,oxygen1 #dd4j to #dh4g per cent4 ,silicon1 #bb4h #cf4b 0 ,aluminum1 #i4i #f4a 0 ,iron1 #i4i #b4d 0 ,calcium1 #f4f #j4i 0 ,magnesium1 #b4g #j4a 0 ,sodium1 #b4d #b4e 0 ,potassium1 #a4g #c4a 0 ---------- ---------- #ajj4j #ajj4j ,according to this table1 the sum total of the amounts of all the elements not mentioned may be estimated as less than one-tenth of one per cent4 of the whole4 ,this statement is rendered all the more striking when it is considered that in this minute fractional part must be included all coal and all the useful metals1 except iron4 ,another authority#a declares that it is probable that an amount equal to ninety-nine one-hundredths of the entire weight of the solid1 liquid and gaseous matter of our globe1 is made up of only thirteen elementary substances4 ,the elements referred to and their relative proportions are approximately represented in the diagram following3 #a ,professor ,j4 ,p4 ,cooke4 ,diagram of the ,composition of our ,globe 7by ,weight47 ---------------------------------------- -------------- ,,sulphur1 ,,hydrogen1 ,,chlorine1 ,,nitrogen1 #ec ,,others --------------------------------- ,,potassium1 ,,sodium1 ,,iron1 ,,carbon1 ,,silicon1 ---------------------------------- ,,aluminum1 ,,magnesium1 ,,calcium1 ---------------------------------------- --------------- ,,oxygen1 ---------------------------------------- ---------------- ,fourth4 ,most of the elements are metals4 ,this may not appear to the ordinary reader until he is informed that terminations in um1 as in case of aluminum1 barium1 cadmium1 calcium and others are intended to suggest that the substances so designated are metals4 ,most of the other elements having names not terminating in um are called non-metals4 ,fifth4 ,each chemical element has an atomic symbol1 an abridgement1 in some form1 of its name4 ,sixth4 ,each chemical element has an atomic weight4 ,as the atomic weight of hydrogen is #a1 without any fraction1 it is easily understood that the weight of one atom of hydrogen is taken as the unit of the system4 ,an inspection of the numbers given shows that in many cases the atoms weigh amounts that are very nearly exact multiples of the weight of an atom of hydrogen4 ,,reading ,,references4 ,atomic ,weights1 ,calculations of ,becker1 ,george ,f4--,atomic ,weight ,determinations3 a digest of the investigations published since #ahad4 7,published as ,part ,,iv of the ,constants of ,nature1 in ,smithsonian ,miscellaneous ,collections1 ,no4 #ceh47 #ahhj4 ,clarke1 ,frank ,w4--,a ,recalculation of the ,atomic ,weights4 7,published as ,part ,v of the ,constants of ,nature1 in ,smithsonian ,miscellaneous ,collections1 ,no4 #dda47 #ahhb4 -------- ,am4 ,chem4 ,jour4 iii1 #bfc4 7#ahha47 ,atomic ,weights1 ,periodicity of ,meyer1 ,lothar4--,chem4 ,news1 xli1 #bjc4 ,atomic ,weights1 ,mendelejeff's ,law of ,am4 ,chem4 ,jour4--iii1 #dee4 ,cooke1 ,j4 ,p4--,chem4 ,philosophy1 p4 #bfe4 ,wurtz1 ,ad4--,atomic ,theory1 p4 #aed4 ,atomic ,weights1 ,arithmetical ,relations of ,hodges1 ,m4 ,d4 ,c4--,silliman's ,journal1 #c;d ,ser4 x1 #bgg4 ,newlands1 ,j4 ,a4 ,r4--,chem4 ,news1 xlix1 #aih4 ,atomic ,weight of ,oxygen4 ,odling1 ,w4--,jour4 of ,chem4 ,soc4 of ,london1 xi1 #ajg4 ,atomic ,weight of ,thallium4 ,cookes1 ,wm4--,chem4 ,news1 xxix1 #ad1 #bi1 #ci1 #ee1 #fe1 #ge1 #he1 #ig1 #aje1 #aae1 #abf1 #acg1 #adg1 #aeg4 ,atomic ,weights1 ,prout's ,hypothesis of ,cooke1 ,j4 ,p4--,chemical ,philosophy1 #bgj4 ,clarke1 ,f4 ,w4--,am4 ,chem4 ,journal1 iii1 #bgb4 7#ahha47 ,gerber4--,silliman's ,journal1 #c;d ,ser4 xxvi1 #bcf4 ,atoms1 ,absolute ,weight of ,annaheim1 ,j4--,jour4 of ,chem4 ,soc4 of ,london1 xxxi1 #ca4 ,elements1 ,defunct ,bolton1 ,h4 ,c4--,american ,chemist1 i1 #a4 ,elements1 ,suggestions that ,elements are ,compound4 ,lockyer1 ,j4 ,n4--,nature1 ,jan'y #b and #i1 also ,nov4 #f1 #ahgi4 ,hastings1 ,c4 ,s4--,criticism of above4 ,am4 ,chem4 ,jour41 i1 #ae4 ,,chapter ,,iii4 ,,names ,,and ,,symbols ,,of ,,elements4 ,any history of the chemical elements1 distinctly points to the enormous stride which chemical discovery has taken within the last hundred years4 ,the dawn of this period was marked by many most important results3 among these may be mentioned the detection of the elementary gases1 oxygen1 hydrogen and nitrogen4 ,the light which these great events threw upon the future of the science enabled the chemists of that early period to perceive that the number of new compound substances then discovered1 and likely soon to be discovered1 called for a multitude of new terms4 ,in #aghg the eminent ,french chemist1 ,lavoisier1 in committee with ,guyton de ,morveau and others of their chemical associates of the ,french ,academy1 suggested a system by which a considerable number of chemical compounds1 both then known and thereafter to be discovered1 might be provided with names at once convenient and suggestive4 ,this system1 slightly modified and considerably extended--to accommodate the yet more widely expanding needs of the science--affords the basis of the chemical language of to-day4 ,a ,few ,principles of ,chemical ,language4 ,it is proposed to explain here a few of the first principles of chemical nomenclature and notation2 that is1 to present a few of the rules by which significant and useful names and symbols are provided4 ,these will be found to meet the wants of hitherto inaccurately known substances1 and even of those formerly unknown4 ,first2 the names of elementary substances long known are retained4 ,thus1 gold and silver are metals that were known in the earliest historical periods1 if not in prehistoric times2 their names1 therefore1 still remain in use4 ,second3 the discoverers of new elementary substances assign the names4 ,in so doing1 they usually invent a name that suggests some fact connected with the substance itself4 ,thus the name nitrogen is derived from two ,greek words 71 nitron1 mineral alkali1 and 1 gennao1 ,i produce7 carrying the suggestion that the gas is one of the constituents of nitre4 ,the name hydrogen is derived from two ,greek words 71 hydor1 water1 and 1 gennao1 ,i produce17 indicating that wherever water exists1 hydrogen is an essential constituent of it4 ,so the name chlorine is derived from a ,greek word 71 chloros1 green17 which reminds the chemist of the fact that chlorine gas possesses a greenish color4 ,the substance oxygen1 however1 was named in a different manner4 ,its name is derived from two ,greek words 71 oxys1 acid1 and 1 gennao1 ,i produce17 signifying a generator of acids4 ,it appears then1 that in this case the name is based1 not on an easily verified fact1 but upon a theory1 current when oxygen was discovered1 of the action of the substance in question4 ,in a certain sense a name thus formed may be considered ill-advised4 ,thus in the case in hand it has turned out that while oxygen is a constituent of a majority of known acids1 it is not essentially an acidifying substance3 many acids are known that contain no oxygen at all1 and again there are a multitude of compounds containing oxygen that are not acids in any proper sense4 ,third2 newly discovered metals are usually given names which1 while they suggest some property of the substance1 have in addition the termination1 um4 ,thus the metal thallium derives its name from a ,greek word 71 thallos1 a green twig17 which carries the suggestion of the fact that thallium and its compounds when highly heated evolve light of a delicate green color4 ,again caesium1 a newly discovered metal1 has a name derived from a ,latin word 7caesius1 blue17 which refers to the fact that caesium and its compounds when highly heated afford light of a blue color4 ,the termination um is used for metals1 after the analogy of the ,latin language which usually has its names of metals end in um4 ,indeed the chemist often makes use of the ,latin names of even those metals that have been long known by more familiar ones4 ,thus for gold the ,latin word aurum is used1 for silver the ,latin word argentum1 for lead the ,latin word plumbum2 it will be seen later that slightly modified forms of these names are very frequently employed when compounds of these metals are to be designated4 ,illustration3 ,,antoine ,,laurent ,,lavoisier3 ,born in ,paris1 ,august #bfth1 #agdc2 died on the scaffold in ,paris1 ,may #hth1 #agid4 ,symbols used for ,atoms4 ,each elementary substance1 or1 strictly speaking1 the minute quantity of it represented by the term one atom1 may be designated in brief by a special letter or short group of letters called the symbol4 ,the usual symbol is the initial letter of the native or the ,latin name of the substance4 ,upon examining the list of elementary substances at page #ac1 it will be seen that the following nine of the names begin with the letter ,c2 of course1 therefore1 in eight cases at least1 the symbol must contain an additional distinguishing letter3 ,accordingly ,c indicates one atom of ,carbon2 ,ca 0 0 ,calcium2 ,cd 0 0 ,cadmium2 ,ce 0 0 ,cerium2 ,cl 0 0 ,chlorine2 ,co 0 0 ,cobalt2 ,cr 0 0 ,chromium2 ,cs 0 0 ,caesium2 ,cu 0 0 ,copper 7,latin word cuprum74 ,it also appears that in the case of metals1 like iron and copper1 known to the ancients the symbols used are derived from the ,latin names4 ,the use of these symbols made from letters--and therefore called literal symbols1 from the ,latin word litera1 a letter--will become apparent as the reader advances2 but it is easily perceived that they afford a convenient abridgement of the longer titles of the elements4 ,the use of literal symbols as an abridgement of the chemical nomenclature was first proposed by ,berzelius1 a ,swedish chemist1 whose eminence in every branch of the science was such that the suggestion here referred to constitutes one of the least of the many and substantial grounds on which his fame rests4 ,,reading ,,references4 ,alchemy4 ,rodwell1 ,g4 ,f4--,the ,birth of ,chemistry4 ,london4 #ahgd4 ,draper1 ,j4 ,c4--,amer4 ,chemist1 v1 #a4 ,mackay1 ,charles4--,memoirs of ,extraordinary ,popular ,delusions4 #b v4 ,london4 #ahfi4 i1 #ic4 ,berzelius4 ,whler1 ,f4--,early ,recollections of ,berzelius4 ,am4 ,chemist1 vi1 #aca4 ,chemistry1 ,history of ,thomson1 ,thomas4--,history of ,chemistry1 #b v4 ,london4 #ahcj4 ,hoefer1 ,f4--,histoire de la ,physique et de la ,chimie4 ,paris4 #ahgb4 ,kopp1 ,hermann4--,geschichte der ,chemie4 #d,th4 ,braunschweig4 #ahdc4 -------- ,die ,entwickelung der ,chemie in der neueren ,zeit4 ,mnchen4 #ahgc4 ,bolton1 ,h4 ,c4--,chem4 ,news4 xxxii1 #cf1 #ef1 #fh4 ,liebig1 ,j4 v4--,familiar ,letters on ,chemistry4 ,whewell1 ,wm4--,history of the ,inductive ,sciences4 #b v4 ,new ,york4 #ahge4 ii1 #bei4 ,illustration3 ,,jons ,,jakob ,,berzelius3 ,born in ,east ,gothland 7in ,sweden71 ,aug4 #bj1 #agii2 died ,aug4 #g1 #ahdh4 ,lavoisier1 ,thomson1 ,thomas1--,history of ,chemistry4 #b v4 ,london4 #ahcj4 ii1 #ge4 ,figuier1 ,l4--,vies des ,savants ,illustres du xviii sicle1 #ddd4 ,brougham1 ,h4--,lives of ,philosophers of the time of ,george ,,iii4 ,edinburgh1 #ahgb4 #bij4 ,nomenclature4 ,morveau1 ,guyton de4--,memoire sur les denominations chimiques1 la necessit d'en perfectionner le systme1 les rgles pour y parvenir1 suivi d'un tableau d'une nomenclature chimique2 ,dijon4 #aghb4 ,lavoisier1 de ,morveau1 ,fourcroy1 ,baum1 ,hassenfratz1 ,adet and others4 ,mthode de nomenclature chimique4 ,paris4 #aghg4 7,the ,boston ,athenum ,library contains a copy of this work47 ,,chapter ,,iv4 ,,classification ,,of ,,the ,,elementary ,,substances4 ,in speaking of the elementary substances some of them have been referred to as metals4 ,what then is the exact idea conveyed by this designating term8 ,everyone can readily picture in his mind some metal or metals like gold1 silver1 tin1 zinc and others that have certain common characteristics1 such as great weight1 and the peculiar brilliancy and power of reflecting light which is described as metallic lustre4 ,another well marked and widely recognized characteristic at once thought of is the facility with which the substances ordinarily known as metals maybe beaten or rolled into thin layers4 ,this property1 called malleability1 7a word derived from the ,latin word malleus1 a hammer17 is not possessed in any striking degree by substances other than metals4 ,thus sulphur is not malleable3 quite the contrary1 it is very brittle4 ,charcoal1 which consists mostly of the elementary substance called carbon1 is likewise not malleable2 neither of these last two substances would be likely to be considered by even an ordinary observer as metals4 ,in fact they are classed as non-metals by the chemist4 ,this division of the elementary substances into metals and non-metals is dwelt upon1 not because it can be called a very important one1 but because it is widely used in works on chemistry and because in deciding to which of these two classes a given substance belongs1 ultimate dependence must be placed upon its chemical characteristics rather than upon its mere mechanical properties4 ,the ,meanings ,associated with the ,term ,metal4 ,the principal properties referred to are best presented in three groups4 ,first4 ,metallic ,properties ,associated with ,mechanical ,relations4 ,an elemental substance accepted as a metal must possess the property of existing in a solid condition2 a weight rather greater than that of most well-known substances2 considerable hardness1 malleability1 ductility 7that is the capability of being drawn out into fine wire74 ,second4 ,metallic ,properties ,associated with ,physical ,relations4 ,a metal should possess the metallic lustre2 the power called opacity1 by reason of which it does not allow light to pass through it2 the noticeable capability of allowing heat to flow in it1 called the power of conducting heat2 the ready capacity for allowing the electric current to flow in it1 called good conducting power for electricity4 ,third4 ,metallic ,properties ,associated with ,chemical ,relations4 ,a metal should possess the power and the tendency to readily form a chemical union with oxygen2 the chemical power to act upon compounds containing hydrogen1 in such a way as to turn the hydrogen out1 and take its place in the old compound and thus form a new one2 the relationship towards the electric current such that when the element is subjected to the galvanic battery1 it tends to gather about the negative pole--in consequence of which characteristic it is usually called electro-positive4 ,but while no known metal appears to possess the entire range of properties with which in thought the ideal one is endowed1 every substance classified as a metal should possess many of them4 ,an illustration of what has been said may be found in metallic mercury4 ,from the fact that under ordinary conditions it is a liquid it is plain that mercury must lack certain of the metallic properties referred to2 that is1 it does not possess the solid form1 it does not possess hardness1 it does not possess malleability1 it does not possess ductility4 ,yet if it is cooled to a low temperature--about forty degrees below zero--it freezes1 in other words becomes solid2 then it possesses many of the distinctly metallic features that it necessarily lacks when in the ordinary liquid condition4 ,of course this liquid condition is a mere incidental circumstance1 due to the temperature which ordinarily prevails upon our earth4 ,if our ordinary temperature were slightly lower than forty degrees below zero1 mercury would then be commonly known as a solid1 hard1 lustrous1 heavy1 malleable metal--capable of course of melting with a slight accession of heat4 ,as a further illustration1 in a somewhat different direction1 mention may be made of the metal lithium4 ,this substance cannot be called heavy1 since it is lighter than water2 indeed it is the lightest solid known4 ,but on the other hand it possesses in a striking degree those chemical features of metals1 such as strong affinity for oxygen and tendency to combine with it1 which have already been detailed in our definition of the ideal metal4 ,the ,term ,non-metal4 ,the term non-metal is suggestive of a negative idea1 and not of any definite or positive one4 ,in fact it is intended to intimate that elementary substances of this class are those which do not properly belong to the other4 ,sulphur and carbon have been already alluded to as examples of non-metals2 other non-metals1 such as oxygen1 hydrogen1 nitrogen and chlorine among the gases1 bromine1 a liquid1 and iodine1 antimony1 phosphorus among solids1 are far less familiarly known to most persons4 ,,reading ,,references4 ,elements1 ,classification of ,williamson1 ,a4 ,w4--,jour4 of ,chem4 ,soc4 of ,london1 xvii1 #baa4 ,chemical ,theory4 ,cooke1 ,josiah ,p41 ,jr4--,the ,new ,chemistry4 ,new ,york4 #ahgd4 ,remsen1 ,ira4--,principles of ,theoretical ,chemistry4 ,philadelphia4 #ahhc4 ,tilden1 ,william ,a4--,introduction to the ,study of ,chemical ,philosophy4 ,wurtz1 ,ad4 7,henry ,watts1 ,tr47--,history of ,chemical ,theory4 ,london4 #ahfi4 ,,chapter ,v4 ,,compound ,,substances4 ,in a previous chapter a list of elementary substances has been given4 ,all other matters known are compounds4 ,from what has been said already1 it is evident that the compounds are very numerous1 indeed that there is practically no limit to the number of possible ones4 ,these compounds are all made up by the union of elementary substances in obedience to the peculiar chemical forces that reside within them4 ,some compounds have only two kinds of elements3 they are called binaries4 ,some compounds have three kinds of elements3 they are called ternaries4 ,other compounds may have four1 five1 six1 or even more kinds of elements grouped together to form one sort of substance4 ,in this place reference will be made principally to binaries and ternaries--that is to the compounds of the simpler forms of constitution4 ,examples of ,binary ,compounds4 ,in discussing binaries it will be well to give at the outset three or four examples for the purpose of illustration4 ,first4 ,the gas known as hydrogen and the gas known as chlorine have the power of combining chemically and producing an entirely new compound1 a compound different from hydrogen and different from chlorine yet containing portions of each of them4 ,this compound is a binary since it consists of but two kinds of elements4 ,it has several names1 one of which is hydric chloride4 ,the chemist frequently represents what is evidently the smallest possible quantity of this substance1 and also its exact composition1 by the expression ,h ,cl4 ,it is plain that this expression means a minute portion of substance formed by the union of one atom of hydrogen1 7expressed by ,h17 and one atom of chlorine1 7expressed by ,cl74 ,second4 ,when sulphur burns in the air1 it produces a blue flame4 ,at the same time a new and peculiar gas is formed which is easily recognized by its choking odor1 similar to that given off by a burning sulphur match4 ,now this odor is one of the properties of a new compound that has been formed3 a compound different from sulphur1 different from oxygen1 yet containing them both and produced by the union of them4 ,the compound is a binary because it contains but two kinds of elements4 ,it is called sulphur dioxide4 ,the name is intended to suggest that there are two atoms of oxygen to one of sulphur in the compound4 ,this idea is further conveyed by the abridged system of notation so commonly used by chemists4 ,thus by this system the smallest possible quantity of the compound in question is expressed as follows1 ,,so4 ,in this expression it is very plain that ,s stands for one atom of sulphur1 and ,o for two atoms of oxygen4 ,third4 ,but sulphur may be made to combine with a still larger amount of oxygen than it takes when it simply burns in the air4 ,then it forms a compound called sulphur trioxide4 ,this is still a binary1 since it contains nothing but sulphur and oxygen1 that is only two elementary substances4 ,expressed in the briefer form the smallest quantity of this compound may be represented by the formula1 ,,so4 ,this expression means a compound arising from the union of one atom of sulphur and three atoms of oxygen4 ,fourth4 ,when lead is heated to the melting point it is observed to become coated with a constantly increasing mass of a kind of ashes4 ,a pound of the lead when heated in this way produces considerably more than a pound of dross4 ,the formation of this dross is explained by the fact that when lead is heated it really burns1 though of course the rapidity of the burning depends upon the amounts of heat and air to which the lead is subjected4 ,evidently the lead1 in burning1 has something added to itself4 ,that something is a gas which is ever present in the atmosphere and which is called oxygen4 ,the dross is a chemical compound of lead and oxygen4 ,it is called plumbic oxide1 and its smallest quantity is represented by the formula1 ,pb,o4 ,in this formula it is easy to see that ,pb stands for an atom of lead 7whose ,latin name is plumbum71 and ,o for an atom of oxygen4 ,the dross then is a binary compound4 ,a multitude of such examples of binary compounds might be given2 probably those already cited are sufficient for the present4 ,it will be advantageous to the reader to carefully learn the names and the formulas of the binary compounds thus far given1 since they are selected examples which may be used again further on4 ,examples of ,ternary ,compounds4 ,the ternary compounds are those which consist of three kinds of elements2 of course they are more complicated in structure than the binaries4 ,this fact1 however1 must not deter the reader from the attempt to understand them at the outset1 for the principal ternaries are acids and salts1 and everyone knows that acids and salts are among the most important compounds which the chemist has to employ4 ,as examples of ternary acids mention will be made of two of the principal ones used by the chemist4 ,and first1 nitric acid is a compound of hydrogen1 nitrogen and oxygen4 ,the formula of the smallest individual portion of it is ,,hno4 ,these letters signify that nitric acid contains one atom of hydrogen1 combined with one atom of nitrogen and three atoms of oxygen4 ,now this nitric acid forms a great many salts4 ,a simple example may be found in that one containing silver4 ,thus when nitric acid and silver are warmed together1 either a part or the whole of the silver dissolves4 ,a new substance is produced which is commonly called nitrate of silver4 ,by the chemist it is oftener called argentic nitrate4 ,its solution may be dried into the form of a white crystalline substance1 one that has long been accepted as a member of the class of salts4 ,its formula is ,ag,n,o4 ,it is plain that this last formula is employed as a short way of expressing that the salt is a compound of more than one kind of element--of three kinds in fact--and that these elements are in the proportions of one atom of silver1 one atom of nitrogen1 and three atoms of oxygen4 ,promise was made to refer to two important acids2 sulphuric acid is the second one4 ,commercially this substance is by far the most important of all the acids4 ,indeed its manufacture is one branch of the greatest chemical industry devised by man--the alkali trade4 ,evidently it is important that the chemist should be thoroughly acquainted with sulphuric acid1 with its composition1 its formula1 its way of chemically acting on other substances1 and the things or products that it gives rise to when it has opportunity so to act4 ,now sulphuric acid has the formula ,h,,so4 ,this formula means that sulphuric acid is a ternary1 being made up of three different kinds of elements1 namely two atoms of hydrogen1 one atom of sulphur and four atoms of oxygen4 ,further sulphuric acid forms a multitude of salts4 ,thus it forms one containing silver4 ,this is commonly called sulphate of silver1 though the chemist generally calls it argentic sulphate4 ,the formula of argentic sulphate is ,ag,,so ,when this formula is firmly acquired by the reader so that he can readily compare it with others already mentioned1 a certain simple and distinct relationship may be traced4 ,thus comparing ,argentic sulphate1 ,ag,,so with ,sulphuric acid1 ,h,,so it is evident that in the one1 two atoms of silver have taken the places of two atoms of hydrogen that appeared in the other4 ,and such is usually the case3 when silver takes the place of hydrogen1 it does so1 atom for atom4 ,indeed argentic nitrate1 ,ag,n,o1 already described1 illustrates this fact4 ,it is a compound product closely related to nitric acid1 ,,hno1 the only difference of construction being that here also one atom of silver has taken the place of one atom of hydrogen4 ,the ,purpose of this ,chapter4 ,the purpose of this chapter has been to suggest a few facts respecting the nature of chemical compounds and also to show how the science of chemistry employs its peculiar language both in its longer and shorter forms4 ,this language is very comprehensive4 ,in fact it is too elaborate for full explanation here4 ,the plan contemplated is to give at this point a few hints as to its nature and scope1 and to develop it only so far as may be necessary to the succeeding stages of our progress4 ,it is proper to suggest at this point that no single scientific man--nor society of them--can enforce the use of any particular words upon the great body of chemists4 ,for this reason1 as well as for others1 there still prevails the use of different chemical names for the same substance4 ,thus the compound of hydrogen and chlorine first referred to as represented by the formula ,h,cl1 has at least four widely used names3 first1 a name merely suggestive of its component parts1 that is hydric chloride2 second1 names which suggests something in addition to its component parts1 namely that it is an acid1 thus it is called both chlorohydric acid and hydrochloric acid2 third1 an old fashioned name1 which still retains its hold upon the commercial world1 namely1 muriatic acid4 ,this same general principle applies to a great many other substances1 and while it is true that it thus increases the number of names in the chemical language1 it likewise incidentally enriches that language4 ,for in many cases it has come to pass1 little by little1 that these different names are appropriated to slightly differing forms of the same substance1 and so the name employed often conveys to the intelligent chemist as definite a shade of meaning as do the different synonyms used in the descriptions of every-day affairs by any accomplished author4 ,a single example will elucidate this point4 ,the term oil of vitriol would usually be defined as meaning sulphuric acid4 ,but the words sulphuric acid convey1 strictly speaking1 the same meaning as the formula ,h,,so ,this latter substance1 however1 is of very rare occurrence alone3 it is usually associated with varying quantities of water1 and is then spoken of as sulphuric acid of varying degrees of dilution4 ,now in commerce the term oil of vitriol has come to be appropriated exclusively to that dilution consisting of about #hi per cent4 of sulphuric acid1 ,h,,so with #aa per cent4 of water1 ,h,o1 both taken by weight4 ,,reading ,,references4 ,notation1 ,chemical ,frankland1 ,e4--,experimental ,researches in ,chemistry4 #c4 ,london4 #ahgg4 ,williamson1 ,a4 ,w4--,jour4 of ,chem4 ,soc4 of ,london1 xvii1 #dba4 ,frankland1 ,e4--,loc4 cit4 xix1 #cgb4 ,madan1 ,h4 ,g4--,loc4 cit4 xxiii1 #bb4 ,council ,chem4 ,soc4 of ,london4--,instructions to ,abstractors from ,current ,publications4 7#ahgi47 ,chem4 ,news4 xlvii1 #ae4 ,,chapter ,,vi4 ,,the ,,construction ,,of ,,substances4 ,in order to understand the chemical construction of substances it is necessary to consider three terms much used by the chemist3 these terms are1 ,mass1 ,molecule1 ,atom4 ,evidently the words relate to three grades of magnitude in which matter is capable of existing2 it is equally plain that of the series the mass represents the largest individual portion of substance1 and the atom the smallest1 while the molecule represents the intermediate one4 ,the ,chemical ,use of the ,term ,mass4 ,whoever looks about him sees substances existing in masses4 ,this is true of vast mountain chains and equally true of the smallest grains of matter that are recognized as the humblest components of those peaks4 ,but the smallest of these visible masses is made up of particles still more minute--yet perhaps of precisely the same kind4 ,for the chemist possesses means of subdivision of substances by which he may make them into minute fractional parts that are measurable and are all just alike1 and he may continue this process long after the portions have sunk below the reach and range of ordinary vision4 ,a lump of pure sugar as big as a cubic inch may be mechanically divided by any one into many smaller ones1 each little one being easily recognized by the ordinary senses as possessing the sweetness1 the crystalline construction1 the whiteness1 the solidity1 the brilliancy1 the power of dissolving in water and indeed a great many other well-known characteristics that pertain to sugar4 ,but the chemist is able to continue the subdivision of the sugar much further4 ,this he does by recourse to processes not exactly mechanical though closely allied to them3 by processes often called physical as distinguished from purely mechanical ones4 ,he may thus reduce the sugar to fragments of such extreme minuteness that while they do not impress our senses as larger portions do1 yet each fragment is capable of displaying to a competent scientific observer the certain and sure chemical properties that always belong to sugar1 whether in large lumps or in small ones1 and which in fact belong to nothing but sugar4 ,speaking generally1 all particles producible by mechanical subdivision are masses1 while the same is true of most particles producible by physical subdivision4 ,the ,chemical ,use of the ,term ,molecule4 ,but there is a point where any attempt at further scientific subdivision results in a new and startling change3 at this stage the last individual that can properly be called sugar is dissected and loses entirely the characteristics of sugar4 ,the fragments produced by the wreck of the last particle are of a new kind4 ,they are portions of carbon1 portions of hydrogen1 portions of oxygen4 ,this last particle of sugar is separated into its ultimate constituents only by chemical processes4 ,this last particle before it is broken up is called the molecule1 the word meaning a little portion4 ,the single individual thing it refers to cannot be detected by the eye1 nor can it be in any way appreciated except by scientific means4 ,but a chemical change of the last multitude of molecules at once1 is practicable to everybody1 and it is to a certain extent recognized by every one who heats sugar until it turns to a charred mass4 ,this charred mass is mainly carbon--one of the components of the now ruined sugar--and it is very unlike sugar in every way4 ,the chemist can show that when sugar is charred1 the oxygen and the hydrogen go off mostly in the form of gases or vapors1 and that on this account they escape detection at the hands of all ordinary observers4 ,the ,chemical ,use of the ,term ,atom4 ,it appears then that the chemist is able to subdivide molecules into smaller parts4 ,but he finds that further division is at a certain stage forbidden him4 ,he can take the oxygen out of the sugar1 but he cannot take anything but oxygen out of oxygen2 he can take hydrogen out of sugar1 but he cannot take anything but hydrogen out of hydrogen2 he can take carbon out of sugar1 but he cannot take anything but carbon out of carbon4 ,as a result of all chemical study of common sugar the chemist has fixed upon the following as expressing most closely the facts as he knows them3 ,the formula of one molecule of pure cane sugar1 is ,c,h,o ,the chemical formula of any substance expresses much more than the reader would at first imagine4 ,thus the formula ,c,h,o conveys at once to the chemist a series of facts1 some of which may be amplified as follows3--one molecule of sugar contains three kinds of substance3 carbon1 hydrogen and oxygen3--each of these kinds of matter exists in the molecule in separate minute portions such as in the present state of human knowledge are divisible only in a limited way3 thus the carbon of one molecule of sugar is divisible into twelve parts1 and no further2 the hydrogen of one molecule of sugar is divisible into twenty-two parts1 and no further2 the oxygen of one molecule of sugar is divisible into eleven parts1 and no further4 ,definition of the ,term ,atom4 ,now at last the atom has been reached4 ,it is that portion of any kind of matter that is to human beings indivisible in fact4 ,it has already been stated that there are only sixty-six different kinds of atoms1 it appears then that there are only sixty-six kinds of matter that at present cannot be chemically subdivided into different components4 ,it is true that some persons consider that certain intricate chemical processes suggest that what have been here called indivisible atoms are themselves really capable of yet further decomposition4 ,without attempting here to sustain or to demolish this proposition or to say what the future of chemical investigation may reveal1 it may be safely remarked that adequate proof has not yet been offered of the ability of any one to successfully accomplish a decomposition of the sixty-six atoms enumerated4 ,plainly then just as bricks may be made into a building1 and a series of buildings may make a city1 and a series of cities may exist in a state1 so atoms may combine together to form molecules1 and molecules may cohere together to form a mass1 and visible masses may be placed side by side and give rise to the ordinary objects recognized about us4 ,true the comparison suggested is not strictly carried out in all particulars4 ,but the difficulty not a serious one3 for a city might contain a multitude of houses each one so similar that no difference could be distinguished between them1 just as a mass of sugar does in fact contain molecules of which each one is so like its neighbor that the most refined chemical methods discover no difference between them4 ,again these same houses might be composed of combinations of brick and other materials differing among themselves1 but closely corresponding in every house4 ,so the molecule of sugar does contain atoms of carbon1 hydrogen and oxygen1 the atoms of one kind differing distinctly and absolutely from the atoms of the other kind4 ,but here the parallelism seems to cease4 ,for while all bricks and other components of a building are capable of being split into smaller portions1 the atoms composing the molecule are found by the chemist to be absolutely indivisible in the present state of knowledge4 ,employing still further the illustration already in hand it may be added that just as the walls of a dwelling might contain bricks either of the same kind as to their color1 shape and weight1 or else differing in these or other respects1 so a molecule may be a little group of atoms of the same kind1 or it may be a group of atoms of different kinds4 ,thus the hydrogen gas molecule is composed of two atoms each just alike1 and each being hydrogen4 ,this molecule is represented by the formula ,h or ,h--,h4 ,so a molecule of chlorine gas is composed of two atoms each just alike and each being chlorine4 ,this molecule is represented by the formula ,cl or ,cl--,cl4 ,everything ,built up of ,atoms4 ,now each of the sixty-six elementary substances has molecules composed of atoms1 and each molecule of a given element is composed of atoms of the same kind4 ,and further all the vast and countless myriad of compound substances1 whether buried in the heart of the solid earth1 whether drifting in the wandering courses of the ocean's currents1 whether floating in the airy mass which is wrapped about our globe1 whether components of distant planets of unknown constituents1 whether parts of the seething mass which pours its volcanic torrents millions of miles out from the surface of our central sun--all these substances are constructed1 so far as we know1 of inconceivably minute atoms of varying kinds bound together by chemical attraction into molecules1 the molecules being piled one upon another into those masses whose reaction our dull senses can appreciate4 ,atoms and ,molecules ,manifest ,chemical ,affinity4 ,but to the chemist1 atoms1 molecules and masses possess an interest of another kind4 ,each atom and each molecule is endowed with an invisible1 occult power called chemical affinity4 ,this power acts like an unseen spirit possessed of likes and dislikes4 ,by reason of it an atom of hydrogen for example instantly binds itself to an atom of chlorine whenever opportunity offers1 but will never1 even under the most favorable circumstances1 combine with an atom of gold4 ,finally this attractive force is a kind of energy of which no true explanation can be offered4 ,all that human beings can do is to attentively study it as it manifests itself in the relations of elementary substances and compound substances one toward another4 ,indeed one of the principal offices of chemistry is to study these relationships as they develop4 ,it is the multitude of possible relationships and actions of which the numberless substances known are capable1 that gives to chemistry its great scope and variety and that makes it such a vast field for experiment1 for discovery of facts1 and for industrial application of them4 ,,reading ,,references4 ,atoms and ,molecules4 ,barker1 ,g4 ,f4--,amer4 ,chemist4 ,nov4 #ahgf4 p4 ms4 #afd4 ,stoney1 ,johnstone4--,phil4 ,mag4 xxxvi1 #ada4 ,clerk-,maxwell1 ,j4--,encyclopdia ,britannica1 article ,atoms4 -------- ,theory of ,heat4 ,new ,york4 #ahgb4 ,thompson1 ,sir ,wm4--,nature4 ,mch4 #ahgj4 ,tait1 ,p4 ,g4--,recent ,advances in ,physical ,science4 ,london4 #ahgf4 p4 #bhc4 ,mayer1 ,a4 ,m4--,lecture ,notes on ,physics4 p4 #eb4 ,cooke1 ,j4 ,p4--,the ,new ,chemistry4 ,new ,york4 #ahha4 pp4 #bi-dc4 -------- ,american ,cyclopdia1 article ,molecule4 ,,chapter ,,vii4 ,,how ,,chemical ,,affinity ,,works4 ,it is an interesting fact that elements and compounds manifest an exceedingly great variety of tendencies to combination4 ,fragments of matter1 so small that no eye perceives them1 have1 wrapped up in themselves1 a multitude of determinate powers4 ,a given atom as of lead1 for example1 will very readily combine with oxygen and with some other substances1 but it seems to absolutely refuse to combine with nitrogen4 ,so hydrogen will combine very readily with chlorine and with many other elements1 but it refuses to form any union with silver and with many other elementary substances4 ,it cannot be called a whim that determines the kind of element or its amount that a certain substance will combine with1 though the likes and dislikes of atoms are in this respect exceedingly marked and even incomprehensible4 ,but however impossible it may be to explain an element's friendly or unfriendly deportment toward another1 it is possible in each case to learn the facts with certainty1 for each atom possesses its true individuality and is always constant and consistent in its affinities and hates4 ,it is the purpose of this chapter to present in an orderly manner some of the peculiarities of this mysterious power of chemical affinity4 ,first4 ,each ,kind of ,atom ,has ,its ,peculiar ,chemical ,affinities4 ,chemical affinity seems to reside within the atom as a permanent1 ever present and guiding energy4 ,thus while iron oxidizes readily--that is manifests under a multitude of common conditions a willingness to combine with oxygen and form a new compound called oxide of iron1 and well-known under the name of iron-rust--gold on the other hand oxidizes unwillingly2 indeed in order to get it to combine with oxygen it must be coaxed by means of circuitous and carefully planned devices4 ,but these atoms are always consistent in their action1 for iron under any and every condition oxidizes more readily than gold does4 ,second4 ,chemical ,affinity ,acts ,only ,under ,favorable ,conditions4 ,while chemical action often works with most intense energy it does so only when certain outside and incidental conditions are favorable4 ,thus carbon has under certain conditions an affinity for oxygen and manifests its tendency to combination1 with an intensity that is scarcely surpassed4 ,in order however to awaken and vivify the dormant inclination it must be stimulated by certain definite and favorable conditions2 the most important of these conditions is a certain amount of warmth4 ,the stores of fuel in our cellars--the coal and the wood and all other combustible things--are surrounded by great quantities of oxygen which winds its way1 with every slightest stir of the mobile air1 in and out through all the crevices that the fuel affords1 passing continually in the immediate neighborhood of ample quantities of atoms of carbon4 ,but it does not ordinarily unite with them4 ,subject the whole or any portion of these combustible things to a slight rise in temperature--then the atoms of oxygen and the atoms of carbon seem to arouse themselves from repose3 they unite in friendly and firm grasp1 and what is called chemical union takes place4 ,to the ordinary observer the heat that is produced is the most notable sign of this kind of combination4 ,the chemist1 however1 discovers a yet more conclusive evidence1 for he finds that several kinds of new molecules have been produced2 one of these kinds1 for example1 is expressible by the name carbon dioxide and by the formula ,,co4 ,evidently this formula means that each atom of carbon has united with two atoms of oxygen4 ,in this familiar example heat is the agency that stimulates the atoms to a display of the chemical force that previously was slumbering within them4 ,light and the electric current and the vital forces of animals and plants1 though acting in a manner less familiar to us1 are energizers of chemical affinity and all have their proper influence to make atoms join in union2 indeed in some cases they make atoms burst from each others bonds and fly away to more congenial conditions4 ,third4 ,each ,atom ,has a ,certain ,equivalence or ,atom-,fixing ,power4 ,the chemist also recognizes each atom as possessing certain peculiar numerical preferences in its combinations2 a manifestation of chemical affinity called equivalence4 ,thus when carbon burns in a stove1 by reason of the air passing by it on its way to the chimney1 it seizes upon some of the oxygen atoms and binds a definite number of them to itself4 ,if there is much air1 each atom of carbon of the millions present1 picks out two atoms of oxygen from the air2 if there is but little air1 each atom of carbon has to be satisfied with one atom of oxygen4 ,now in these two cases of course different substances are formed4 ,the first1 whose composition is represented by the formula ,,co1 has already been spoken of as carbon dioxide4 ,to the other1 whose composition is represented by the formula ,,co1 is applied the name carbon monoxide4 ,here then we see that the same atom may sometimes combine with two atoms of oxygen and sometimes with only one4 ,further the chemist knows four simple and familiar compounds whose molecules illustrate very strikingly the difference of equivalence of different atoms4 ,these compounds are the following3 ,chlorohydric acid 7,hydric chloride71 ,h,cl or ,h--,cl ,h-- ,water 7,hydric oxide71 ,h,o or ,o ,h-- ,h-- ,ammonia gas 7,hydric nitride71 ,h,n or ,h-- ,n ,h-- ,h-- ,marsh gas 7,hydric carbide71 ,h,c or ,h-- ,c ,h-- ,h-- ,it has been found advisable to adopt the atom of hydrogen as the standard of equivalence or atom-fixing power4 ,it is plain that by this method of comparison the atom chlorine may be said to have the equivalence one1 since it combines with one atom of hydrogen4 ,and so the atom oxygen may be said to have the equivalence two1 since it combines with two atoms of hydrogen4 ,and the atom nitrogen may be said to have the equivalence three1 since it combines with three atoms of hydrogen4 ,and the atom carbon may be said to have the equivalence four1 since it combines with four atoms of hydrogen4 ,the language of chemistry sometimes presents the same observed facts in a slightly different form1 somewhat as follows3 ,chlorine is said to have one point of attraction and is called a monad 7a term derived from the ,greek word 1 monas1 a unit74 ,oxygen is said to have two points of attraction and is called a dyad 7a term derived from the ,greek root 1 dyas1 two74 ,nitrogen is said to have three points of attraction and is called a triad 7a term derived from the ,greek word 1 trias1 a group of three74 ,carbon is said to have four points of attraction and is called a tetrad 7a term derived from the ,greek word 1 tetras1 four74 ,while hydrogen as the basis of the system has the uniform equivalence one1 and is always a monad1 and oxygen its close friend and ally has always the equivalence two1 and is always a dyad1 most other elements have some variety of equivalence4 ,thus chlorine has at different times different equivalences1 sometimes one1 sometimes three1 or five1 or seven4 ,so nitrogen has at different times the different equivalences1 one1 three1 five4 ,so carbon has sometimes an equivalence two1 sometimes four4 ,fourth4 ,chemical ,changes ,neither ,create nor ,destroy ,matter4 ,when chemical changes are produced by reason of the action of chemical affinity1 there is never either gain in weight or loss in weight4 ,in other words there is no creation of matter and no destruction of it4 ,in former times1 people who observed the disappearance of solid matter when charcoal burns1 thought that the substance was destroyed--partly if not wholly4 ,the modern chemist finds1 however1 that the carbon is only turned into the form of an invisible gas1 and that by the use of appropriate appliances he can find the weight of this gas1 and compare it with that of the carbon producing it4 ,in the combustion of carbon the chemical change is represented by the following equation3 ,c ,o ,,co ,one atom of ,two atoms of ,one molecule of ,carbon ,oxygen ,carbon dioxide #ab #cb #dd parts by weight4 parts by weight4 parts by weight4 _/ _/ #dd #dd ,this equation means that the chemist has discovered1 by careful experiments1 that when any twelve parts by weight of carbon--say twelve pounds--are completely burned1 they always unite with thirty-two corresponding parts of oxygen 7in this case thirty-two pounds71 and they produce forty-four parts by weight of carbon dioxide 7in this case forty-four pounds74 ,and so in all chemical changes the substances taking part--whether solid1 liquid1 or gaseous--may be weighed1 and the sum of the weights of all the matters finally produced is just equal to the sum of the weights of the original factors4 ,fifth4 ,chemical ,changes are ,often ,attended by ,displays of ,force4 ,in many chemical changes the union of the atoms is attended with the production of heat1 or electricity1 or some other form of energy4 ,now it is a law derived from modern discoveries that the amount of energy given out by any chemical union is fixed and invariable1 and that it is just the same in amount as the quantity of that kind of energy that is absorbed when such chemical action is reversed4 ,sixth4 ,chemical ,changes ,produce ,striking ,results4 ,each of the atoms of matter is in itself fixed and unchangeable and it possesses through all its varied combinations an inherent character which belongs to it and which no human being can permanently alter4 ,but when atoms unite to build up either simple or complex molecules1 the various original atomic characters are so blended and balanced and reinforced as to afford in the molecular product an entirely new and unexpected set of properties4 ,an example of these principles is found in the union of copper1 sulphur1 oxygen and hydrogen4 ,these substances may combine to form a new molecule which is called cupric sulphate1 and which has the composition expressed by the formula ,cu,s,o #e;,h,o4 ,of the constituents of this molecule1 copper is red1 sulphur is yellow1 oxygen is colorless1 hydrogen is colorless2 but when they unite the cupric sulphate formed is blue1 that is its color is not that of either of its constituents1 nor is it intermediate between them4 ,there is simply a new and unexpected result1 and one which in the present state of knowledge cannot be explained2 it can merely be recorded4 ,and this example is only one of a myriad4 ,throughout nature chemical changes most marked--and to the human thought unexpected--arise from the union of familiar elementary substances4 ,seventh4 ,chemical ,atoms ,unite in ,obedience to ,definite ,law4 ,careful chemical study of the way in which atoms combine has developed the following as a fundamental law of nature4 ,the same chemical compound always contains the same kind and number of elementary atoms1 and these atoms are united in the same proportions by weight4 ,this law is a formal statement of facts similar to those already referred to in paragraphs third and fourth of this chapter4 ,it does not therefore seem to call for further explanation at this point4 ,the ,modern ,atomic ,theory4 ,the same chemical study which has developed the truth of the law just stated has also given rise to the modern atomic theory4 ,the chemist is constrained to believe that matter is composed of ultimate indivisible particles called atoms4 ,while these atoms are invisible to mortal eye even with the help of the finest known optical appliances1 yet when their existence is once admitted this admission affords an explanation that is a satisfactory one1 and indeed the only one that harmonizes with the multitude of observed chemical and physical laws4 ,this atomic theory1 in its essential particulars1 was suggested in the early part of this century by ,dr4 ,john ,dalton1 who was a teacher of mathematics in ,manchester1 ,england1 and who died as recently as in #ahdd4 ,dalton found recreation in chemical experiments1 and the mathematical turn of his mind led him to express the results of his chemical analyses in a new numerical form4 ,thus previous to his time it had been customary to express the composition of all substances in the ordinary percentage form4 ,now ,dalton found that if some special weight was adopted as the unit1 a variety of new and previously concealed facts was revealed4 ,the idea to be here conveyed is partially but perhaps sufficiently expressed by the following examples derived from the two compounds of carbon already referred to3 ,illustration3 ,,john ,,dalton3 ,born at ,eaglesfield4 7,england47 ,sept4 #eth1 #agff2 died ,july #bgth1 #ahdd4 ,composition of the ,two ,compounds of ,carbon and ,oxygen4 ---------------------------------------- -------------- ,,expressed ,,in ,,per ,,cents4 ---------------------------------------- -------------- ,carbon ,monoxide 7,,co74 ,carbon ,dioxide 7,,co74 ,carbon1 #dc - per cent4 #bg per cent4 ,oxygen1 #eg per cent4 #gc - per cent4 -------- -------- #ajj #ajj ---------------------------------------- -------------- ---------------------------------------- -------------- ,,expressed ,,in ,,dalton',s ,,form4 ---------------------------------------- -------------- ,carbon ,monoxide 7,,co74 ,carbon ,dioxide 7,,co74 ,carbon1 #ab parts by weight1 #ab parts by weight4 ,oxygen1 #af parts by weight4 #cb parts by weight4 ------ ------ #bh #dd ---------------------------------------- -------------- ,in ,dalton's expression it is at once evident that1 as compared with the weight of carbon1 the amount of oxygen in carbon dioxide is exactly twice what it is in carbon monoxide3 but to the ordinary unmathematical mind this fact is buried in the percentage statement4 ,dalton's experiments with still other compounds gave him results showing a simplicity of relationships similar to that obtained from the carbon compounds just referred to4 ,to his mind these facts suggested immediately the idea that an elementary substance is made up of atoms each of a determinate weight1 and that these atoms combine by wholes and not by fractional parts1 and that although it is impossible to weigh any atom separately1 yet the weight ratios of a multitude of them that combine as wholes express at once the weight ratios of the atoms themselves4 ,he thus got the idea of atomic weights and constructed the first table of them4 ,since ,dalton's first declaration of his atomic theory1 the combining numbers of the different atoms have been studied by chemists with the most thoughtful care and the most painstaking methods known to modern science2 and tables have been constructed showing the combining numbers which are believed also to be the true atomic weights for all the various elements thus far recognized4 ,,reading ,,references4 ,atomic ,constitution of ,bodies4 ,saint-,venant4--,jour4 of ,chem4 ,soc4 of ,london4 xxx1 pt4 ,,ii1 #dgb4 ,atomic ,philosophy4 -------- ,amer4 ,chemist1 iii1 #cbf4 ,atomic ,theory4 ,williamson1 ,a4 ,w4 7and others47--,jour4 of ,chem4 ,soc4 of ,london4 xxii1 #cbh1 #dcc4 ,wurtz1 ,ad4--,the ,atomic ,theory4 ,new ,york4 #ahha4 ,atomic ,volumes1 ,etc4 ,avogadro4--,annales de ,chimie et de ,physique4 #c ,sr4 xiv1 #ccj2 xxix1 #bdh4 ,atoms1 ,vortex ,theory of ,thomson1 ,sir ,wm4--,phil4 ,mag4 #ahfg4 ,thompson1 ,j4 ,j4--,science4 iii1 #bhi4 ,tait1 ,p4 ,g4--,recent ,advances in ,physical ,science4 ,london4 #ahgf4 p4 #bhc4 ,atomic ,weights1 ,dalton's ,first ,table of ,roscoe1 ,h4 ,e4--,chem4 ,news4 xxx1 #bff4 ,chemical ,operations1 ,calculus of ,brodie1 ,b4 ,c4--,jour4 of ,chem4 ,soc4 of ,london4 xxi1 #cfg4 ,dalton1 ,john ,henry1 ,w4 ,c4--,life of ,dalton4 ,london4 #ahed4 ,definite ,proportions1 ,variability in ,law of ,boutlerow4--,silliman's ,journal4 #c;d ,ser4 xxvi1 #fc4 ,cooke1 ,j4 ,p4--loc4 cit4 #caj4 ,equivalents of the ,elements4 ,dumas1 ,j4--,annales de ,chimie et de ,physique4 #c ,sr4 lv1 #abi4 ,energy4 ,stewart1 ,balfour4--,the ,conservation of ,energy4 ,new ,york4 #ahgd4 ,tait1 ,p4 ,g4--,recent ,advances in ,physical ,science4 ,london4 #ahgf4 ,encyclopdia ,britannica4 vol4 viii4 ,gaseous and ,liquid ,states of ,matter4 ,andrews1 ,t4--,jour4 of ,chem4 ,soc4 of ,london4 xxiii1 #gd2 xxx1 pt4 ,,ii1 #aei4 ,ramsey1 ,w4--,jour4 of ,chem4 ,soc4 of ,london4 xlii1 #acf4 ,matter1 ,constitution of ,ditte1 ,a4--,annales de ,chimie et de ,physique4 #e ,sr4 x1 #ade4 ,nomenclature of ,salts4 ,madan1 ,h4 ,g4--,jour4 of ,chem4 ,soc4 of ,london4 xxiii1 #bb4 ,,chapter ,,viii4 ,,hydrogen4 ,this substance is one of the most interesting with which the chemist has to deal4 ,on account of its chemical and physical properties1 by reason of the many important compound substances into which it enters1 by reason of the part it has played in the history of chemical progress1 it is entitled to a large share of the student's attention4 ,meaning of the ,word ,hydrogen4 ,the name hydrogen was applied to it some time later than the first recognition of the substance4 ,the word is derived from two ,greek words 71 hydor1 water1 and 1 gennao1 ,i form or produce71 the word as a whole meaning water former4 ,in fact hydrogen is in all water wherever that substance exists4 ,that this is a very comprehensive expression appears when it is remembered that the atmosphere always contains water diffused through it in the form of invisible vapor even before that vapor is precipitated as the gentle dew1 or the crystalline snow1 or the streaming rain4 ,again1 water in seas and oceans1 lakes and rivers1 is the mantle of nearly three-fourths of the earth's surface4 ,every living being on the dry land1 whether animal or vegetable1 contains large quantities of water in its structure3 the blood of the higher animals is nearly nine-tenths water4 ,while water is the principal substance containing hydrogen1 this gas exists also as a constituent part of a great many other solid and liquid matters found in the earth4 ,why ,free ,hydrogen is not ,found in the ,earth4 ,hydrogen scarcely ever exists on our globe alone1 that is in the free or uncombined condition4 ,indeed there are certain definite reasons why it should not4 ,these are based mainly upon the very strong chemical affinity that hydrogen has for oxygen4 ,now1 as has been declared already1 the latter substance is the most abundant element in nature1 and it exists in very large quantities in our atmosphere4 ,spread all over the surface of the earth then1 the free oxygen of the air stands prepared to combine with hydrogen wherever the latter may be liberated4 ,such combination might not occur1 it is true1 unless initiated by influence of heat or some flame of fire2 but owing to the constant agitation of the air by reason of uniform currents like trade winds1 as well as those produced when the atmosphere is agitated by violent storms1 any mixture of hydrogen and oxygen would be likely soon to come into contact with some flame or fire1 and so these components would enter into combination4 ,thus hydrogen would not be likely to remain long uncombined even were it produced in considerable quantity by natural terrestrial operations4 ,the ,discoverer of ,hydrogen4 ,hydrogen was first distinctly described and its properties as a special kind of gaseous matter clearly pointed out in the year #agff1 by an ,english chemist1 the ,honorable ,henry ,cavendish4 ,this philosopher1 the son of ,lord ,charles ,cavendish1 and the grandson at once of the ,duke of ,devonshire and the ,duke of ,kent1 is one of the most curious characters in the history of the natural sciences4 ,he was of an exceptionally careful1 thorough and painstaking temper1 which well fitted him for the scientific pursuits which were the prime objects of his thoughts4 ,sir ,humphry ,davy said of him3 8,the accuracy and beauty of his earlier labors have remained unimpaired amidst the progress of discovery1 and their merits have been illustrated by discussion and exalted by time40 ,in addition to his possession of many special aptitudes for the exact studies to which he devoted his entire existence1 it should be recognized that he lived at a period that was remarkably favorable to the pursuit of the natural sciences4 ,the times1 the state of knowledge1 the condition of society all over ,europe seemed to be ripe for this kind of progress1 for in ,scotland1 in ,england1 in ,france1 in ,germany1 in ,sweden there appeared experimenters of unsurpassed skill1 and chemistry as a science had then its birth under most fortunate auspices4 ,cavendish was very peculiar in his manners and habits1 living in great seclusion and retirement and in the most simple and methodical manner2 indeed his oddities attained for him the unenviable distinction of a place in a book devoted to the lives of ,english eccentrics4 ,in that work1 as well as in ,dr4 ,wilson's life of him1 are many amusing anecdotes of his way of life4 ,one most remarkable episode was his inheritance of wealth4 ,though poor in his youth he was suddenly made rich in middle life by a bequest whose origin is scarcely known4 ,m4 ,biot neatly described him as 8le plus riche de tous les savants1 et probablement aussi1 le plus savant de tous les riches40 ,he lived on however in as great seclusion as before1 his chosen associates being his flasks and his thermometers4 ,his millions made no observable impression upon his habits1 notwithstanding at his death they made him the largest holder of the stock of the ,bank of ,england4 ,lord ,brougham says that ,cavendish probably uttered fewer words in the course of his life than any other man who ever lived to fourscore years1 not at all excepting the monks of ,la ,trappe--who were bound to perpetual silence except in cases of absolute necessity4 ,illustration3 ,,joseph ,,black1 ,m4 ,d4 ,born in ,bordeaux1 in #agbh2 died in ,edinburgh1 ,nov4 #bf1 #agii4 ,why ,hydrogen was not ,discovered ,earlier4 ,doubtless those prehistoric men who in earliest days looked about upon the face of the earth1 curiously examining their heritage from the ,creator1 were familiar with water in its various forms4 ,they must have prized its bland and refreshing powers and have learned many of its most important uses4 ,but the idea that it is made up of more than one kind of substance or matter was not suspected until very recent times1 and not proved until the masterly investigations of ,cavendish clearly set forth the facts4 ,indeed the very idea of a chemical compound1 that is of a substance as made up of inconceivably small portions of matter in a union of almost inconceivable intimacy1 an idea very familiar to students of the present day1 probably did not enter the minds even of those profound thinkers who suggested the earlier atomic philosophies4 ,in fact the notion of chemical union is scarcely more than a century old4 ,moreover1 hydrogen is a gas1 and the notion of gas is itself decidedly a modern one4 ,it was first stated in well-defined form in the year #ageb1 by ,dr4 ,joseph ,black1 professor in ,glasgow and ,edinburgh4 ,black clearly and conclusively demonstrated the existence of airs of a different kind from that familiar to us in our atmosphere4 ,it is true ,van ,helmont and even others1 fully one hundred years before ,black's time1 had known and stated more or less distinctly the existence of a gas or air different from that we breathe1 but owing to a variety of circumstances these wonderful discoveries were allowed to relapse into forgetfulness4 ,thus the human race lost for a century much advantageous knowledge2 but probably the general social advancement of those times had not then prepared mankind for the benefits which the development of modern chemistry has conferred upon the present citizens of the world4 ,again1 experimenting with gases was not well understood until about the year #aggj1 when ,joseph ,priestley invented that contrivance for manipulating them known as the pneumatic trough1 for which no better substitute has yet been devised4 ,further1 in water--which has already been referred to as the most abundant and widely diffused compound of hydrogen--the partner elements are bound together by a chemical affinity that cannot be readily overcome4 ,this intensity of attractive force between the constituent elements is therefore another reason why the true composition of water was so long an unsolved riddle and why hydrogen was not earlier recognized as a thing or kind of matter by itself1 although in its principal compound--one of the most admirable gifts of the ,creator to man--it was well-known from the first days of the human race4 ,how ,hydrogen is ,prepared4 ,hydrogen may be obtained by the chemist in several ways3 ,first4--,there is a method of directly tearing the elements composing water apart from each other4 ,considered theoretically this process is a most direct and simple one4 ,in order to realize its results1 however1 advantage must be taken of the galvanic current4 ,this force may be obtained readily it is true3 thus in most cases where two metals1 dipped in a liquid1 are connected by a wire it is generated4 ,but no one knows fully what the current is4 ,the words galvanic current and voltaic current suggest the two investigators1 ,galvani and ,volta1 who were the pioneers in this field1 but they give nothing that can be called an explanation of the wondrous1 invisible1 imponderable form of energy referred to4 ,it is a force of an exceedingly interesting character and about which a certain considerable body of knowledge has been collected4 ,among the variety of facts known about it is that one which relates to water2 namely1 when the poles or electrodes of a suitable galvanic battery are dipped into a vessel of water1 bubbles of gas may be seen to flow freely from each of them4 ,the gases may be collected in a vessel placed over the electrodes1 but the experimenter may well beware of incautiously treating what has now been produced2 he has obtained a mixture of oxygen and hydrogen from the original water1 and these elements which he has rended apart from their more intimate union1 are ready upon the approach of the smallest flame to rush into union again1 with extraordinary violence1 and in such a way as to produce a tremendous explosion4 ,in the act of this explosion1 therefore1 water is again produced1 first as expansive vapor1 then condensible back to the liquid drops whence it came4 ,illustration3 ,,fig4 #f4--;,apparatus for decomposition of water1 7by action of two cells of the ,bunsen galvanic battery17 and for collection of hydrogen and oxygen gases in separate receivers over the two electrodes of the battery4 ,if however the product from each electrode is collected by itself in a separate tube1 the one gas is found to be very different from the other4 ,the one is found to be hydrogen1 the other oxygen4 ,in accordance with the formula ,h,o--which it has before been stated represents the composition of water--the hydrogen is found to be given off in a bulk or volume that is twice as great as that of the oxygen obtained at the same time from the same amount of water4 ,second4--,hydrogen may be obtained by bringing into contact with water under proper conditions certain substances that have a very strong affinity for its oxygen and at the same time but little affinity for its hydrogen4 ,now every one is familiar with the fact that iron rusts readily in the air4 ,the chemist can demonstrate that this rust is a compound of iron and oxygen4 ,the union of these elements under ordinary conditions suggests at once that that union arises from an affinity between the iron and the oxygen4 ,this affinity is much greater at high temperatures1 for it is well known that iron rusts more violently when subjected to heat4 ,these facts then are made use of for the purpose of withdrawing oxygen from water and thus forcing the hydrogen out in the free or uncombined condition so that it may be obtained and experimented upon4 ,illustration3 ,,fig4 #g4--;,apparatus for preparation of hydrogen gas4 ,steam1 generated in the small retort1 is conveyed through the tube placed in the gas furnace2 iron turnings within the tube being highly heated1 decompose the water-vapor1 which thereby evolves hydrogen4 ,the liberated gas is collected in the little bell-glass4 ,to produce hydrogen by this method1 there must be provided a long iron pipe which passes through a hot furnace2 the pipe should contain fragments of iron such as iron turnings1 or iron filings1 or pieces of iron wire4 ,then a current of steam must be passed through the pipe4 ,the iron becomes red hot1 and under these circumstances manifests more affinity for the oxygen of the steam than the hydrogen does4 ,the iron then grasps the oxygen and holds it fast4 ,as a result a peculiar kind of oxide of iron of a black color is produced4 ,its chemical formula is ,fe,o and it is called by chemists ferroso-ferric oxide4 ,the iron has now taken the place as a partner of the oxygen that the hydrogen formerly had4 ,the hydrogen is thus cast out from its combination and is set free as an uncombined gas1 in which liberated condition it is expelled at the end of the tube4 ,the chemical action between the iron and the steam may be represented by the following equation3 ,fe #d;,h,o ,three atoms of ,four molecules of ,iron1 ,water1 #afh #gb parts by weight4 parts by weight4 _/ #bdj ,fe,o #d;,h ,one molecule of ,four molecules of ,ferroso-ferric oxide1 ,hydrogen1 #bcb #h parts by weight4 parts by weight4 _/ #bdj ,the gas produced as just described may be collected by adjusting a suitable tube in connection with the pipe containing the iron4 ,when the gas is examined it is found to be in fact hydrogen4 ,it will burn with a blue flame and perform all the various actions that acknowledged hydrogen will4 ,third4--,there are other metals1 not known to the common every-day uses of life but still familiar to the chemist1 which have far greater affinity for oxygen than iron has4 ,one such metal is that called sodium4 ,its affinity for oxygen is so great that it cannot be long preserved if exposed to the air3 a block or lump of it would1 in a day or two in the open air1 turn entirely to a mass of rust of sodium1 that is oxide of sodium4 ,this metal therefore is preserved by the chemist in bottles containing petroleum oil4 ,the oil keeps the air away from the metal2 moreover the oil contains no oxygen in its composition as many other liquids do4 ,this metal sodium though heavier than the oil is lighter than water4 ,if thrown upon water it floats4 ,but by virtue of its intense affinity for oxygen1 it at the same time decomposes the water4 ,it draws the oxygen to itself and it liberates the hydrogen4 ,some chemical skill is requisite in the performance of this apparently simple experiment1 for occasionally the violent affinities involved set the sodium and the hydrogen on fire and give rise to dangerous explosions4 ,when properly conducted1 however1 the hydrogen from this process may be collected in a vessel and its various characteristics displayed4#b #b ,appleton's 8,young ,chemist10 ,philadelphia1 ,cowperthwait ,co4 pp4 #bf1 #bg1 #bh4 ,fourth4--,the most common way of producing hydrogen is by bringing together sulphuric acid and zinc4 ,the formula for sulphuric acid is ,h,,so4 ,now the zinc has affinity for the compound radicle ,,so1 known as the sulphuric acid radicle4 ,the chemical change is represented by the following equation3 ,zn ,h,,so ,one atom of ,one molecule of ,zinc1 ,sulphuric acid1 #fe #ih parts by weight parts by weight _/ #afc ,zn,s,o ,h ,one molecule of ,one molecule of ,zinc sulphate1 ,hydrogen1 #afa #b parts by weight parts by weight _/ #afc ,here it is plain that by reason of its affinities the zinc has taken the place of the hydrogen--or the place which the hydrogen formerly held as related to the sulphuric acid radicle1 ,,so--and that the hydrogen thereby left without anything to combine with1 appears as a free and uncombined substance4 ,the hydrogen produced by this method can be readily collected and examined4 ,illustration3 ,,fig4 #h4--;,apparatus for production of hydrogen1 by action of sulphuric acid on zinc1 and for collection of the gas in a receiver4 ,perhaps it ought to be stated that neither of the processes thus far explained is likely to yield hydrogen in an absolutely pure condition4 ,the various substances used are likely themselves to contain associated with them small amounts of other substances which give some impurity to the gas evolved4 ,the ,powers and ,properties ,manifested by ,hydrogen4 ,hydrogen has been seen1 from the explanation already given1 to be a gas4 ,down to within a few years it resisted all attempts to liquify it4 ,chemists submitted it to intense cold and enormous pressure and to both these influences at the same time but without avail4 ,within a few years1 however1 by use of ampler resources and contrivances for the application of these condensing agencies1 it has been brought down to the liquid and perhaps even to the solid state4 ,as a gas it is colorless1 odorless1 tasteless4 ,bulk for bulk it is the lightest substance known in nature4 ,thus a quart of atmospheric air1 light as it is1 weighs over fourteen times as much as a quart of hydrogen4 ,a cubic inch of gold weighs more than two hundred thousand times as much as a cubic inch of hydrogen4 ,this lightness is properly illustrated by inflating a soap bubble with hydrogen rather than with air4 ,when soap bubbles are filled with air they fall1 unless indeed carried upward by a temporary current2 but when filled with hydrogen they invariably rise with great rapidity4 ,by reason of this great lightness hydrogen was formerly used for the inflating of balloons1 but at the present day illuminating gas is so much cheaper1 that the latter is generally used1 although it is much heavier than hydrogen4 ,diffusive ,power of ,hydrogen ,gas4 ,it is not inappropriate to call attention here to certain interesting relations that hydrogen manifests towards gases and solids4 ,thus hydrogen possesses to a marked degree that curious facility of passing into and permeating other gases which is spoken of as its diffusive power4 ,true1 this power is possessed by all gases to a certain extent2 but in rapidity of action none approach hydrogen4 ,as early as #ahbe a ,german chemist named ,dbereiner announced his observations of this power4 ,he noticed that upon collecting some hydrogen in a cracked jar1 placed in a pneumatic trough1 the hydrogen leaked out into the air more rapidly than the air went in4 ,so that in fact the water of the trough rose on the inside of the jar4 ,it has been since discovered that when almost any two gases whatsoever1 if only of different densities1 are separated by a partition having fine cracks or holes in it1 the lighter gas always moves out into the heavier one more rapidly than the heavier gas moves in4 ,as hydrogen is the lightest of all1 of course it diffuses into other gases with the greatest rapidity4 ,in liquids1 hydrogen does not ordinarily dissolve in any considerable quantity4 ,with solids however it displays some properties that are well nigh incredible4 ,thus it has a very curious aptitude for passing into the very interior of certain solid metals4 ,the white1 compact1 solid metal palladium1 although it has no visible pores1 has the power of swallowing up into itself in some mysterious way nearly a thousand times its bulk of this gas2 and again a thin sheet of this same solid metal1 air-tight to all appearances1 allows hydrogen to pass through it as easily as a sieve does water4 ,the ,most ,interesting ,chemical ,property of ,hydrogen4 ,by all means the most interesting chemical property of hydrogen is its power to unite with oxygen4 ,when it does so unite all the phenomena of combustion appear4 ,these phenomena are generally the production of heat1 light1 flame1 and the formation of some new chemical compound4 ,so then when hydrogen unites with oxygen1 it burns1 it gives out light 7although that light is of but feeble intensity71 it gives out an enormous quantity of heat1 it forms an oxidized product4 ,this product is water1 but water that--owing to the great heat of the combustion--is raised to the form of invisible vapor4 ,when however a jet of hydrogen gas is burned under a bright but cool bell-glass1 the deposit of mist quickly formed on the inside of the glass shows that the vapor produced by combustion has now condensed on the bell to minute liquid drops4 ,illustration3 ,,fig4 #i4--;,a glass tube held over a hydrogen flame1 for the purpose of developing a musical note4 ,in the matter of the heat involved1 hydrogen has the distinction of being above every other substance4 ,one pound of hydrogen when burned under favorable conditions evolves heat enough to raise over thirty-four thousand pounds of water from zero centigrade to one degree centigrade1 or nearly the same as from #cb degrees ,fahrenheit to #cd degrees ,fahrenheit4 ,this expression of the calorific power of hydrogen has the same meaning as the following more technical one1 namely3 burning hydrogen affords over thirty-four thousand thermal units4 ,now carbon1 a fuel which nature has provided1 and which is certainly admirably fitted to be man's chief combustible1 yields but eight thousand thermal units of the kind just referred to1 and for purposes of comparison it maybe added that sulphur yields but two thousand thermal units4 ,hydrogen ,cannot ,supply the ,uses of ,atmospheric ,air4 ,notwithstanding the remarkable evidences of chemical affinity suggested by what has just been said1 hydrogen can in no sense act as a substitute for the atmospheric air4 ,thus it does not support animal life nor will it sustain the combustion of a candle4 ,a living animal immersed in a room full of hydrogen would be drowned in it2 a burning candle carried into such a chamber would be extinguished as if dipped in water4 ,in fact the comparison with drowning is very proper1 for in drowning a living animal the water does not chemically injure the organism2 the hydrogen and the water1 in the cases supposed1 have similar action in depriving both the animal and the taper of their requisite oxygen4 ,the ,uses to ,which ,hydrogen ,may be ,put4 ,illustration3 ,,fig4 #aj4--;,disposition of apparatus for the production of water1 by combustion of dry hydrogen in air4 ,hydrogen as the elementary gas finds but few applications in the arts4 ,it is true that from what has been said1 it appears as if its wonderful calorific power might be utilized in some of the arts where high temperatures are requisite4 ,but the cost and difficulties attending its preparation1 the liability to loss during its storage1 and the danger from explosion while in actual use1 these and other circumstances have led even the skilled artisan to content himself in most cases with other though inferior materials4 ,but if the reader has attentively followed the introductory chapters of this work he must have perceived that hydrogen is made of great service in many of the measurements employed by the chemist4 ,it has been noted that it is used as the standard of equivalence or atom-fixing power4 ,it has been spoken of as the standard of atomic weight1 and from what has appeared in the remarks upon its lightness it will seem that it has been properly adopted as the standard of density for gases4 ,,reading ,,references4 ,cavendish1 ,henry ,brougham1 ,h4--,lives of ,men of ,letters and ,science1 etc4 p4 #dbi4 ,timbs1 ,j4--,english ,eccentrics1 etc4 p4 #acb4 ,wilson1 ,george4--,life of ,cavendish4 ,london4 #ahea4 ,black1 ,joseph ,brougham1 ,h4--,lives of ,men of ,letters and ,science1 etc4 ,london4 #ahde p4 #cbd4 ,diffusion of ,gases4 ,graham1 ,t4--,elements of ,chemistry4 #b v4 ,london4 #ahej4 i1 #hd4 -------- ,jour4 of ,chem4 ,soc4 of ,london4 xvii1 #ccd4 ,occlusion of ,hydrogen by ,palladium4 ,graham1 ,t4--,jour4 of ,chem4 ,soc4 of ,london4 xxii1 #dai4 ,,chapter ,,ix4 ,,balloons4 ,the remarkable lightness of hydrogen early suggested the fitness of that gas for the inflation of balloons4 ,from the earliest ages men have desired to navigate the air4 ,the drudgery of land travelling over hills and mountains1 over marshes and streams1 through jungles and forests1 has led men to prefer voyaging even by sea4 ,thus the people of the ,united ,states crossed the stormy ,atlantic in large numbers long before they traversed the wilds of the ,american continent to the ,pacific coast2 and the early voyagers from ,new ,york to the ,golden ,gate of ,san ,francisco preferred the water way1 though it led them through an enormous distance and around the perilous ,cape ,horn1 rather than undertake the shorter course over the ,rocky ,mountains4 ,even at a later date1 the sea voyage to ,panama1 and across the ,isthmus1 and again by water way to ,san ,francisco was the ordinary course until ,pacific railroads created a land pathway from one side of the continent to the other4 ,so men1 envying the bird in its flight through the mobile air1 have desired yet more to conquer its smooth courses1 just as their keels have found a sliding pathway in the watery main4 ,but no truly successful air-voyaging was possible until about one hundred years ago4 ,illustration3 ,,fig4 #aa4--,one of the balloons of the ,montgolfier brothers4 ,invention of the ,balloon4 ,in the year #aghc two brothers named ,stephen ,montgolfier and ,joseph ,montgolfier1 succeeded in sending up into the atmosphere the first air-ship worthy of the name4 ,they lived in ,france at a little town named ,annonay1 situated about forty miles south of ,lyons1 and at the junction of two small streams whose clear waters flow into the river ,rhone4 ,here the brothers carried on with increasing skill and success the manufacture of paper1 a business which their father had conducted there before them1 and which in fact is carried on by their descendants of the same name even at the present day4 ,the brothers1 ,stephen and ,joseph1 were skillful mechanics1 and one of them1 it is said1 had studied ,dr4 ,priestley's work on 8,different ,kinds of ,air40 ,this seems to have led him to the idea of aerial navigation4 ,however that may be1 it is a matter of history that on the #eth of ,june1 #aghc1 the two brothers sent up from ,annonay a balloon about thirty-five feet in diameter4 ,naturally it was made of paper1 though lined with linen4 ,the ascensional power of this balloon was due to a proportional lightening of the air within it by the influence of heat4 ,the heat was produced by the combustion of a large quantity of chopped straw1 and also from burning wool previously saturated with a little alcohol4 ,probably the ,montgolfier brothers did not then fully know why their balloon ascended3 they appear to have thought that it arose because of the volumes of smoke that filled it4 ,it is hardly probable that either ,stephen or ,joseph ,montgolfier thought at that time of using hydrogen for their air-ship1 notwithstanding its extraordinary lightness had been a matter of public scientific knowledge for six or seven years4 ,this may seem the more strange in view of the admitted fact that as early as #agfg ,dr4 ,black1 of ,edinburgh1 had publicly demonstrated that a suitable vessel filled with hydrogen would ascend in the atmosphere as cork does in water4 ,of course they did not think of employing illuminating gas1 because that substance was not then in public use4 ,the ,first ,balloon ,ascension in ,paris4 ,the news of the wonderful and successful experiment at ,annonay was quickly sent to ,paris1 where it produced a profound sensation4 ,the interest extended from scientific men to the royal family and the court1 and indeed to the entire population of the capital4 ,for the ,french people--perhaps even more than other nations of ,europe--seem to have been particularly interested at this time in the study of chemical and physical science4 ,the king instantly issued a summons for the ,montgolfiers to come to ,paris4 ,but the ,parisians could not even await their arrival4 ,the scientists of the capital1 though but partially informed as to the character of the experiments performed at ,annonay1 at once set to work4 ,they decided upon hydrogen gas as probably the best fitted for their purposes4 ,whereupon they filled a globular balloon with this gas1 and prepared to try it in public upon the ,champ-de-,mars4 ,it is said that three hundred thousand people--that is1 nearly half the population of ,paris--gathered together1 crowding every adjacent avenue1 to witness the unparalleled undertaking4 ,the liberation of the aerial messenger was announced to the public by a salvo of artillery4 ,the balloon immediately shot upward and1 piercing the clouds1 was soon lost to view4 ,when afterward it slowly descended it reached the ground some fifteen miles from ,paris4 ,here a troop of peasants who detected the strange apparition1 were at first struck with alarm but quickly rallied1 attacked the strange monster and of course soon reduced it to shreds4 ,the whole chain of circumstances created so much excitement that the ,government thought proper to issue a proclamation upon the subject4 ,a copy of this interesting document is here presented in its original form4 ,perhaps some readers will find the accompanying translation acceptable3 ,french ,proclamation ,respecting ,balloons4 ,avertissement au peuple sur l'enlvement des ballons ou globes en l'air4 ,on a fait une dcouverte dont le gouvernement a jug convenable de donner connaissance1 afin de prvenir les terreurs qu'elle pourrait occasioner parmi le peuple4 ,en calculant la diffrence de pesanteur entre l'air appel inflammable et l'air de notre atmosphre1 on a trouv qu'un ballon rempli de cet air inflammable devait s'lever de lui-mme dans le ciel jusqu' au moment o les deux airs seraient en quilibre1 ce qui ne peut tre qu' une trs grande hauteur4 ,la premire exprience a t faite ,annonay1 en ,vivarais1 par les sieurs ,montgolfier1 inventeurs4 ,une globe de toile et de papier de cent cinq pieds de circonfrence1 rempli d'air inflammable1 s'leva lui-mme une hauteur qu'on n'a pu calculer4 ,la mme exprience vient d'tre renouvele ,paris1 le #bg aot cinq heures du soir1 en prsence d'un nombre infini de personnes4 ,un globe de taffetas enduit de gomme lastique1 de trente-six pieds de tour1 s'est lev du ,champ-de-,mars jusque dans les nues1 o on l'a perdu de vue4 ,on se propose de rpter cette exprience avec des globes beaucoup plus gros4 ,chacun de ceux qui dcouvriront dans le ciel de pareils globes1 qui prsentent l'aspect de la lune obscurcie1 doit donc tre prvenir que1 loin d'tre un phnomne effrayant1 ce n'est qu'une machine toujours compose de taffetas ou de toile lgre recouverte de papier1 qui ne peut causer aucun mal1 et dont il est prsumer qu'on fera quelque jour des applications utiles aux besoins de la socit4 ,lu et approv1 ce #c septembre1 #aghc4 ,,de ,,sauvigny4 ,notice to the public relative to the ascension of balloons or globes into the air4 ,a discovery has been made to which the government considers it advisable to call public attention1 with a view of preventing alarms which it otherwise might occasion among the people4 ,upon calculating the difference of weight between the gas called inflammable air and the air of our atmosphere1 it has been discovered that a balloon filled with this inflammable air ought to rise of itself to a height in the sky such that the air within and that without will be in equilibrium1 a condition which will not be reached except at a very great elevation4 ,the first experiment of this sort has been made at ,annonay1 in ,vivarais1 by the ,messrs4 ,montgolfier1 the inventors4 ,a globe of cloth and paper one hundred and five feet in circumference and filled with inflammable air rose of itself to a height which the observer could not calculate4 ,the same experiment has just been repeated at ,paris on the #bgth of ,august at #e o'clock in the afternoon1 in presence of a vast number of persons4 ,a sphere of taffeta coated with gum elastic1 thirty-six feet in circumference1 ascended from the ,champ-de-,mars even to the clouds1 in which it became lost to sight4 ,it is contemplated repeating this experiment with very much larger globes4 ,anyone who discovers in the sky globes of this sort which present the appearance of the moon when slightly obscured1 may therefore be warned that1 far from being an alarming phenomenon1 this is nothing but a machine always constructed of taffeta or of light cloth covered with paper1 which cannot do any injury1 and which it is thought will assume at some future time a form that will prove useful to the public4 ,read and approved1 ,september #c1 #aghc4 ,,de ,,sauvigny4 ,the enthusiasm created by the original experiment of the ,montgolfier brothers led soon after to the election of both of them to the ,academy of ,sciences4 ,moreover their invention was not allowed to rest long in its original form4 ,as early as ,november of the same year1 #aghc1 two ,french gentlemen had the courage to risk their lives in an ascension from ,paris in a balloon of the ,montgolfier construction4 ,they floated freely away and made their landing in safety4 ,one of them1 however1 ,de ,rozier by name1 on a later occasion attempted to cross the ,channel in a double balloon1 one part containing hydrogen1 the other heated air in the ,montgolfier style4 ,but at a great altitude the hydrogen balloon took fire from the other1 and ,de ,rozier and his companion were dashed to pieces on the rocks of the ,french coast4 ,since that early rash attempt thousands of interesting and safe balloon ascensions have been made1 and increased knowledge of the scientific principles has largely contributed to the pleasure and comfort of the aeronaut4 ,yet the contrivance has been in most cases little more than a scientific toy4 ,illustration3 ,,fig4 #ab4--;,gay-,lussac and ,biot making their balloon ascension for scientific observations in #ahjd4 ,the atmospheric air has thus far baffled the inventive power of man to such an extent that the balloon as a mechanical contrivance has been subjected to but few decided improvements since the ,montgolfiers' first experiments1 and ascensions have afforded comparatively meagre scientific or other results4 ,indeed the most of them have been conducted for personal gratification or popular entertainment4 ,of course there are marked exceptions4 ,thus on the #bdth of ,august1 #ahjd1 two of the youngest but most distinguished of ,french physicists1 ,messrs4 ,gay-,lussac and ,biot1 made an important ascension4 ,their voyage was upon the suggestion of the ,french ,academy of ,sciences1 and they were well equipped with apparatus for making observations4 ,their results1 particularly in magnetism1 showed the same laws prevailing in the higher air as upon the earth4 ,but as there were afterwards expressed some doubts as to the accuracy of these observations1 ,gay-,lussac made a later and higher ascent alone4 ,on the #afth of ,september he attained an altitude of twenty-three thousand feet1 the greatest reached up to that date4 ,his experiments on this occasion verified those made before4 ,of particular interest was his test of the composition of the atmosphere4 ,the bottle of air collected at this great height was found upon analysis to possess the same proportional amounts of oxygen and nitrogen as that collected at the surface of the earth4#c #c ,of ,gay-,lussac and this ascension there is told a pretty tale1 which ,i will not mar by making a translation3 8,parvenu la hauteur de #gjjj mtres1 il voulut1 dit-il1 essayer de monter plus haut1 et se dbarrassa de tous les objets dont il pouvait rigoureusement se passer4 ,au nombre de ces objets figurait une chaise en bois blanc1 que le hasard fit tomber sur un buisson1 tout prs d'une jeune fille qui gardait les moutons4 ,quel ne fut pas l'tonnement de la bergre6--,comme et dit ,florian4--,le ciel tait pur1 le ballon invisible4--,que penser de la chaise1 si ce n'est qu'elle provenait du paradis8--,on ne pouvait objecter cette conjecture que la grossiret du travail3 les ouvriers1 disaient les incrdules1 ne pouvaient l-haut tre si inhabiles4 ,la dispute en tait l1 lorsque les journaux1 en publiant toutes les particuliarits du voyage de ,gay-,lussac1 y mirent fin1 en rangeant parmi les effets naturels ce qui jusqu' alors avait parut un miracle40--,arago3 ,eloge de ,gay-,lussac4 ,illustration3 ,,fig4 #ag4--,microscopic despatches1 received in ,paris by carrier pigeons1 enlarged by the magic lantern4 ,the height of this ascent has since been surpassed by ,messrs4 ,glaisher and ,coxwell1 of ,england1 who on ,sept4 #e1 #ahfb attained an altitude of about thirty-seven thousand feet4 ,recent ,use of ,balloons4 ,hydrogen is the lightest substance known1 and this consideration tends to make it a particularly favorable one for the inflation of balloons4 ,but we have seen that it was not until after the ,montgolfier experiments that hydrogen came into considerable use for this purpose4 ,hydrogen is still occasionally prepared for purposes of this sort4 ,it is then produced by the action of sulphuric acid upon zinc4 ,the equation already given explaining this action is as follows3 ,zn ,h,,so ,one atom of ,one molecule of ,zinc1 ,sulphuric acid1 #fe #ih parts by weight4 parts by weight4 _/ #afc ,zn,s,o ,h ,one molecule of ,one molecule of ,zinc sulphate1 ,hydrogen1 #afa #b parts by weight4 parts by weight4 _/ #afc ,in case zinc is not at hand1 iron turnings have been made to answer the same purpose2 and the chemical change in this event is represented by an equation of very similar form3 ,fe ,h,,so ,one atom of ,one molecule of ,iron1 ,sulphuric acid1 #ef #ih parts by weight4 parts by weight4 _/ #aed ,fe,s,o ,h ,one molecule of ,one molecule of ,ferrous sulphate1 ,hydrogen1 #aeb #b parts by weight4 parts by weight4 _/ #aed ,both of these methods of producing hydrogen are still somewhat used where balloons have to be inflated at points distant from a city gas supply4 ,but the manufacture of illuminating gas is now so general1 even in small towns1 that this substance is oftener used at the present day4 ,the superior convenience with which it may be obtained makes it preferred to hydrogen1 notwithstanding the greater ascensional power of the latter substance4 ,illustration3 ,,fig4 #ac4--;,carrier pigeon having attached to his tail a quill containing microscopic photographs of despatches to be sent into ,paris during the siege4 ,illustration3 ,,fig4 #ad4--,the tube of quill containing messages as attached to the tail-feathers of a carrier pigeon4 ,balloons have been used somewhat in recent wars4 ,thus they were found of considerable service during the siege of ,paris1 particularly from ,september #bc1 #ahgj1 to ,january #bh1 #ahga4 ,during these last four months of that siege sixty-two balloons left the city1 and they carried out above two million letters and a great many homing pigeons4 ,some of the birds returned1 escaping the ,prussian sharp-shooters1 and brought with them letters and despatches1 printed upon the thinnest of paper1 in the form of microscopic photographs4 ,the balloons also took out of ,paris during the siege two especially notable passengers1 the one1 ,leon ,gambetta1 head of the provisional government1 who left the city for the purpose of conducting the public business in the provinces2 the other1 ,prof4 ,janssen1 who had the courage to venture out in the darkness of early morning so as to escape the rifles of the beleaguring forces4 ,his voyage was for the purpose of reaching the station in ,algeria from which he was to observe the total eclipse of the sun1 to occur a few weeks later1 ,december #bb1 #ahgj4 ,readers who are interested in the use of balloons during this memorable siege will find a most interesting account in ,mr4 ,glaisher's book1 ,travels in the ,air4 ,it contains a description of the manufacture of air-ships in ,paris1 together with a list of the passengers and an account of the freight of those leaving the city when other means of communication with the outside world were cut off4 ,illustration3 ,,fig4 #ae4--,owner's name on the wing of a pigeon4 ,illustration3 ,,fig4 #af4--;,fac-simile of a microscopic despatch as sent by carrier pigeon4 ,letters and messages1 public or private1 to the number of about #ejjj1 were printed on a large sheet of paper4 ,afterwards this sheet was reduced by photography to the size and appearance shown above4 ,the ,centenary of ,ballooning4 ,it is worthy of note that in ,august1 #ahhc1 the centenary of the experiment of the ,montgolfier brothers was celebrated by their descendants and others at ,annonay by a modern balloon ascension and other ftes4 ,these included the dedication of a monument to the two inventors4 ,this monument is soon to be surmounted by a group in bronze representing the two brothers inflating their first balloon4 ,,reading ,,references4 ,balloons1 ,their ,early ,history4 ,figuier1 ,l4--,les ,arostats et les ,aronautes4 ,revue des ,deux ,mondes4 ,oct4 #a1 #ahej4 p4 #aic4 ,this interesting article will well repay the reader4 ,blerzy1 ,h4--,la ,navigation ,arienne4 ,revue des ,deux ,mondes4 ,nov4 #ahfc4 p4 #bgi4 ,claim is here made1 in a general way1 that the original invention of the balloon was made at the close of the #agth century by a ,portuguese named ,gusmao4 ,balloons1 ,their ,recent ,uses4 ,glaisher1 ,james1 and others4--,travels in the ,air4 ,london4 #ahga4 ,hofmann1 ,a4 ,w4--,chem4 ,news4 xxxii1 #bca1 #bda1 #bee1 #bfe4 ,balloons1 ,centenary of ,their ,invention4 ,london ,graphic4 ,aug #be1 #ahhc4 ,balloons1 ,popular ,account of4 ,harper's ,magazine4 ii1 #afh1 #cbc2 xxxix1 #ade4 ,scribner's ,monthly4 i1 #che4 ,gay-,lussac4 ,arago1 ,d4 ,f4 ,j4--,oeuvres ,completes4 ,paris4 #ahed-ei4 iii4 ,the ,boston ,athenum library has this work4 ,,chapter ,x4 ,,chlorine4 ,chlorine is a substance of very great commercial importance on account of its extensive use as a bleaching agent4 ,again it is a constituent of common salt1 and in this form of combination it is both of great value as an article of food1 and it is recognized as widely distributed4 ,thus it exists in salt1 whether that substance is in the brine of the ocean or of mineral springs1 or whether it occurs as a solid rock--as indeed it does in some parts of the world4 ,at ,wieliczka1 in ,austria1 mines of solid salt have been worked for hundreds of years4 ,so also at ,cardona1 in ,spain1 are what may be called quarries of this valuable mineral2 while ,cheshire1 in ,england1 furnishes immense solid deposits from which salt is obtained to supply the enormous industrial establishments using this substance for the production of chlorine and of compounds of sodium4 ,chlorine was first recognized as a distinct substance1 by a ,european chemist1 ,carl ,wilhelm ,scheele1 known only to his neighbors as a humble apothecary4 ,scheele was born at ,stralsund1 a seaport town of ,pomerania1 situated on the little strait which leaves the island of ,rgen in the ,baltic ,sea4 ,he spent the principal portion of his life in ,sweden1 and on this account is often referred to as a ,swedish chemist4 ,though living in great obscurity1 he yet made many discoveries in chemistry which have rendered his name1 otherwise almost unknown1 one of the most brilliant in the annals of this science4 ,it is related of ,scheele that the ,king of ,sweden1 ,gustavus ,,iii41 while on a journey outside of his own dominions1 heard so much of the fame of this chemist1 unknown to him before1 that he regretted having previously done nothing for him4 ,he therefore commanded that ,scheele receive the honor of being created chevalier4 8,scheele80 8,scheele88 said the minister charged with this duty4 8,this is very singular2 what in the world has ,scheele done80 ,the order was peremptory however1 and ,scheele was knighted4 ,but1 as the reader may perhaps divine1 the honor designed for the acute discoverer fell upon another ,scheele--not upon that ,scheele unknown at court but illustrious among the scientists of ,europe4 ,it was this obscure apothecary then1 who added to the list of his other investigations a study of the properties of what was ordinarily considered a dull and uninteresting earthy substance called black magnesia4 ,this study was repaid by the revelation of no less than four hitherto unknown substances3 oxygen1 barium1 manganese1 and finally chlorine4 ,scheele obtained the chlorine in the year #aggd exactly as it is done at the present day1 namely1 by bringing together the two substances1 now called chlorohydric acid and black oxide of manganese1 but then known as muriatic acid and black magnesia4 ,scheele believed1 and other celebrated chemists concurred in the opinion1 that the greenish gas that he discovered was a compound substance4 ,it was not until thirty-six years later1 that is #ahaj1 that the distinguished ,english chemist1 ,sir ,humphry ,davy1 demonstrated that this gas is not a compound1 but is in fact a simple or elementary substance2 and it was he who gave to it the name chlorine1 a name derived from a ,greek word 71 chloros1 meaning light green71 conveying an obvious and convenient reminder of one striking property of the thing referred to4 ,illustration3 ,,sir ,,humphry ,,davy1 ,bart43 ,born in ,penzance1 ,england1 ,dec4 #ag1 #aggh2 died in ,geneva1 ,switzerland1 ,may #bith1 #ahbi4 8,davy1 when not yet thirty-two years old1 occupied1 in the opinion of all those who could judge of such labors1 the first rank among the chemists of this or any other age40 ,how ,chlorine is ,obtained4 ,the preparation of chlorine is a very simple matter4 ,it may be accomplished by placing some powdered black oxide of manganese1 an abundant mineral substance1 in any deep glass vessel1 and then adding to it four or five times its weight of chlorohydric acid4 ,anyone who performs the experiment will soon perceive the greenish gas rising higher and higher in the vessel1 and will soon discover its choking and corrosive odor4 ,moreover the chlorine gas1 which is two and a half times as heavy as air1 accumulates within the flask and stays there some time4 ,this is the process which has already been referred to as that which first revealed the gas to ,scheele1 and this process1 with but slight modification1 is that which to-day furnishes the enormous quantities of chlorine demanded by modern industries4 ,the ,characteristics of ,chlorine4 ,the three most striking properties of chlorine are its noticeable weight--greater than that of the air--its greenish color1 and its exceedingly irritating odor4 ,its influence on the animal organism is very violent3 more than one example can be produced of fatal results following the inhalation of too large quantities of the gas4 ,thus ,pelletier1 a ,french chemist1 died at ,bayonne from the effects of inhaling a considerable quantity of chlorine1 and ,roe1 a young ,irish chemist of ,dublin1 lost his life from the same cause1 while studying the properties of this gas4 ,chlorine1 as a chemical agent1 manifests its activities in connection with two principal properties1 namely3 its affinity for hydrogen and its affinity for the metals4 ,by this statement it is meant that chlorine manifests a strong tendency to combine with hydrogen1 and to combine with metals1 whenever these substances are accessible to it4 ,when it combines with hydrogen it forms the important compound designated by the formula ,h ,cl and called by the chemist chlorohydric acid1 but known in commerce as muriatic acid4 ,when chlorine combines with the metals it forms chlorides of them4 ,thus with the metal sodium it forms the compound designated by the formula ,na,cl and called by the chemist indifferently sodic chloride or chloride of sodium2 these will be recognized as the chemical names for the important and well-known substance1 common salt4 ,chlorine and ,hydrogen ,combine4 ,chlorine and hydrogen have a very strong tendency to combine with each other4 ,they manifest this tendency in a variety of ways4 ,thus1 if the two gases are prepared in a dark room1 they may be there safely mixed together in a glass vessel2 but if the sunlight is allowed to enter and fall upon the vessel1 there is danger of its being shattered by the explosive violence with which the hydrogen and chlorine immediately unite4 ,as a result of this combination1 chlorohydric acid is produced4 ,the chemical change is represented by the following equation3 ,h ,cl #b;,h,cl ,one molecule of ,one molecule of ,two molecules of ,hydrogen1 ,chlorine1 ,chlorohydric acid1 #b #ga #gc parts by weight4 parts by weight4 parts by weight4 _/ _/ #gc #gc ,again1 when chlorine is brought in contact with vegetable or animal substances1 containing hydrogen1 it proceeds to withdraw that hydrogen for its own benefit1 even though these vegetable and animal compounds are thereby destroyed4 ,although this operation1 as well as the foregoing one1 produces chlorohydric acid1 yet neither method is suitable for a determinate preparation of that substance4 ,it is usually better to prepare chlorohydric acid in another way4 ,thus it is easily produced by the action of sulphuric acid upon common salt4 ,experimental ,preparation of ,chlorohydric ,acid4 ,any one who will take a little trouble may prepare chlorohydric acid in the way indicated4 ,the experiment should be conducted as follows3 ,place a small amount of common salt 7,na,cl7 in a small retort2 to it add enough concentrated sulphuric acid to make a thin paste2 connect the neck of the retort with a clean test-tube containing a few drops of water4 ,now gently heat the retort2 chlorohydric acid will be formed and will distil from the retort and condense in the receiver4 ,the chemical change is represented by the following equation3 ,na,cl ,h,,so ,one molecule of ,one molecule of ,sodic chloride1 ,sulphuric acid1 #eh #ih parts by weight4 parts by weight4 _/ #aef ,h,cl ,h,na,s,o ,one molecule of ,one molecule of ,chlorohydric acid ,hydro-,sodic sulphate #cf #abj parts by weight4 parts by weight4 _/ #aef ,the product of the foregoing experiment may be tested in three ways and so shown to be in fact chlorohydric acid4 ,first3 ,take a minute drop on a glass rod and apply it to the tongue and observe the sour or acid taste4 ,second3 ,take a drop on a glass rod and touch it upon blue litmus-paper4 ,it should turn the paper red4 ,third3 ,pour a few drops of the liquid into a solution of argentic nitrate 7that is1 nitrate of silver7 in a test-tube or other convenient vessel3 a white precipitate of argentic chloride will be formed4 ,illustration3 ,,fig4 #ai4--,section of furnace used for manufacture of chlorohydric acid4 ,common salt and sulphuric acid are placed in the large retort ,a2 upon heating1 chlorohydric acid passes into the receivers ,c1 ,c1 ,c4 ,the method of producing chlorohydric acid just described and illustrated1 is followed in the manufacture of the substance for general chemical purposes4 ,it is also employed for the production of the enormous quantities of it incidentally used in the manufacture of bleaching-powder4 ,experiments with ,common ,salt4 ,chlorine has already been shown to combine with the metal silver producing the compound designated by the formula ,ag,cl1 and called argentic chloride and also chloride of silver4 ,this substance may also be prepared very easily somewhat as follows3 ,make a solution of nitrate of silver4 ,prepare it either by dissolving in water the crystals sold by apothecaries1 or by dissolving a small piece of silver in nitric acid4 ,then make a second clear solution1 by dissolving common salt in ordinary water4 ,add the salt solution cautiously1 drop by drop to the silver solution4 ,there immediately appear thick masses of white flakes which sooner or later fall to the bottom of the vessel4 ,these flakes consist of the argentic chloride 7,ag,cl71 also called chloride of silver1 already referred to4 ,the chemical change is represented by the following equation3 ,ag,n,o ,na,cl ,one molecule of ,one molecule of ,argentic nitrate1 ,sodic chloride1 #afi #eh parts by weight4 parts by weight4 _/ #bbh ,ag,cl ,na,n,o ,one molecule of ,one molecule of ,argentic chloride1 ,sodic nitrate1 #adc #he parts by weight4 parts by weight4 _/ #bbh ,this white precipitate produced in this experiment possesses some special interest from its use in photography4 ,in fact chloride of silver1 as a thin film upon the surface of the photographic paper1 is the principal substance which1 by its sensitiveness to light1 produces the photographic picture4 ,in fact any one1 who tries the experiment last described1 will soon observe1 upon preserving the chloride of silver so produced1 that it rapidly grows dark upon exposure to sunlight4 ,bleaching-,powder4 ,the substance known as bleaching-powder may be spoken of in a general way as consisting of lime saturated with chlorine4 ,this description points very justly to the method of producing the substance1 but gives no idea of the chemical arrangement of the constituents4 ,scheele early noticed that chlorine gas possessed decided bleaching power1 and the ,french chemist1 ,berthollet1 soon called attention to the possible applications of the substance in the bleaching industries4 ,but its annoying odor made it impracticable to use chlorine on any large scale in the state of gas1 and forbade the use of it even when dissolved in water4 ,at length1 twenty years after the discovery of the gas--that is in #agih--the plan of absorbing chlorine in lime was hit upon1 and here may be discovered the beginnings of the bleaching-powder industry1 now one branch of the alkali trade1 the greatest chemical industry conducted by man4 ,this bleaching-powder1 at first a mere chemical curiosity1 is now manufactured by the thousands of tons1 and is used in the bleaching of cotton and linen goods1 both in the form of cloth and in the form of the various kinds of paper4 ,in another place reference is made to the vast proportions attained by the alkali industry1 meaning the manufacture of certain compounds of sodium1 the one produced in largest quantities being doubtless sodic carbonate 7,na,,co71 commonly called soda-ash4 ,in trade this substance is called an alkali because of certain alkaline properties it possesses1 but more strictly speaking it is called a salt--sometimes an alkaline salt4 ,in chemistry the single term alkali is reserved for certain compounds called hydrates1 of which indeed sodic hydrate--having the formula ,na,o,h1 and often called caustic soda--is an appropriate example4 ,this latter compound is at present manufactured on a large scale in connection with soda-ash4 ,now although the ,leblanc process--which has long been used for manufacturing soda-ash--is at present meeting with a powerful and successful rival1 yet the older process has still a strong hold upon life in the fact that it gives rise1 as a convenient incidental product1 to vast quantities of chlorohydric acid4 ,the meaning will be better understood when it is explained that the first step of the ,leblanc process is to add sulphuric acid to common salt4 ,two substances are here produced3 the one is sodic sulphate1 to be carried forward until it is turned into sodic carbonate2 the other substance is chlorohydric acid1 a compound largely used in the arts1 and especially in the manufacture of bleaching-powder4 ,illustration3 ,,fig4 #ba4--;,bleaching of pulp for manufacture of paper4 ,illustration3 ,,fig4 #bb4--;,apparatus for producing bleaching-powder 7by passing chlorine gas1 generated in ,a1 upon quicklime spread upon the shelves74 ,in the production of bleaching-powder1 the first step is to mingle this chlorohydric acid and manganese dioxide4 ,chlorine gas is thus generated1 much as it is when the experiment is conducted on a small scale as already described4 ,the chlorine so generated is passed into a chamber provided with shelves and containing slaked lime4 ,hereupon the lime absorbs the chlorine1 giving rise to a new substance called bleaching-powder--also known as chloride of lime4 ,from what has been said it is evident that chemists know perfectly well what elementary substances enter into this compound4 ,but there are decided differences of opinion as to the exact way in which the atoms are arranged4 ,bleaching-powder is generally considered to be a chemical union of calcic hypochlorite and calcic chloride with the addition of calcic hydrate4 ,the following representation may serve as a formula for the compound3 ,ca,cl,o ,ca,cl ,ca,o,h 7,calcic hypochlorite47 7,calcic chloride47 7,calcic hydrate47 ,illustration3 ,,fig #bj4--,representation of the old method of bleaching cotton and linen goods on lawns4 ,illustration3 ,,fig4 #bc4--;,apparatus for 8souring0 cotton cloth by passing it into dilute acid1 before submitting it to the action of bleaching-powder4 ,the use of bleaching-powder offers certain advantages4 ,the following are some of them3 --,the compound is itself white4 --,it is a powder which can be easily handled1 packed and transported4 --,with reasonable precautions1 the active bleaching agent chlorine is retained by the powder in available form for a considerable length of time4 --,in actual use in the process of bleaching1 the entire amount of chlorine originally stored up in the powder may be liberated in contact with the goods to be bleached4 --,the liberation of this chlorine is easily affected4 ,the addition of almost any acid will accomplish it3 even the carbon dioxide of the atmosphere will suffice4 ,in the bleaching of cotton goods chlorine is not the only agent relied upon1 though it seems to be an essential one4 ,at least three other substances are employed to contribute to the bleaching4 ,each of them either removes some colors or stains from the goods1 or so modifies them that the solution of bleaching-powder--one of the last agents to be employed--can the easier finish its work4 ,the three substances referred to are milk of lime1 diluted sulphuric acid1 and sodic carbonate1 also called soda-ash4 ,the pieces of cloth1 being sewed together into continuous strips many miles in length1 pass from one liquor to another1 with washings in water at proper times1 until finally1 after being fully whitened by the chlorine preparation and then receiving the final washing in water1 they emerge from the works1 completely bleached4 ,,reading ,,references4 ,alkali ,trade1 in its ,various ,branches4 ,claus1 ,c4--,chem4 ,news4 xxxviii1 #bfc4 7,ammonia soda47 ,davis1 ,g4 ,e4--,chem4 ,news4 xxxii1 #afd1 #agd1 #ahg1 #aih1 #baj1 #bch4 ,hargreaves1 ,j4--,chem4 ,news4 xlii1 #cbb4 ,kingzett1 ,charles ,t4--,the ,alkali ,trade4 ,london1 #ahgg4 ,lunge1 ,g4--,jour4 of ,chem4 ,soc4 of ,london1 xliv1 #ebd1 #ebh4 ,mactear1 ,j4--,chem4 ,news4 xxxv1 #d1 #ad1 #ag1 #bc1 #ce2 xxxvii1 #af4 ,schmidt1 ,t4--,chem ,news4 xxxviii1 #bjc4 7,ammonia soda47 ,weldon1 ,w4--,chem4 ,news4 xlvii1 #fg1 #gi1 #hg4 7,present condition of soda industry47 ,bleaching ,powder4 ,jurisch1 ,k4--,jour4 of ,chem4 ,soc4 of ,london4 xxxi1 #cej4 ,kingzett1 ,c4 ,t4--loc4 cit4 xxviii1 #djd4 ,kopfer1 ,f4--loc4 cit4 xxviii1 #gac4 ,lunge1 ,g4--,chem4 ,news4 xliii1 #a4 ,stahlschmidt1 ,c4--,jour4 of ,chem4 ,soc4 of ,london4 xxxi1 #bgi4 ,wolters1 ,w4--loc4 cit4 xxviii1 #djd4 ,chlorine ,industry1 ,future of ,hurter1 ,f4--,jour4 of ,chem4 ,soc4 of ,london4 xlvi1 #bbe4 ,chlorine1 ,preparation of ,berthelot4--,annales de ,chimie et de ,physique4 #e ,sr4 xxii1 #dfd4 ,davy1 ,sir ,humphry4 ,davy1 ,john4--,collected ,works and ,memoirs of ,sir ,h4 ,davy4 ,london1 #ahci4 ,paris1 ,john ,a4--,life of ,sir ,humphrey ,davy4 ,london1 #ahca4 ,brougham1 ,h4--,lives of ,men of ,letters1 etc4 ,london1 #ahde4 p4 #ddh4 ,cooke1 ,j4 ,p4--,scientific ,culture4 ,boston1 #ahha4 p4 #aa4 ,salt ,mines of ,europe4 ,harper's ,magazine1 i1 #gei4 ,scheele1 ,c4 ,w4 ,hoefer1 ,f4--,histoire de la ,physique et de la ,chimie4 ,paris1 #ahgb4 p4 #dig4 ,,chapter ,,xi4 ,,bromine4 ,bromine is an elementary substance1 which was first recognized as such in the year #ahbf4 ,it was detected by ,antoine ,jerome ,balard1 a ,french chemist1 who1 at the age of twenty-four1 was so fortunate and skillful as to discover this interesting substance4 ,he lived at ,montpellier1 not far from ,marseilles and but a few miles from the ,mediterranean4 ,the waters of this great inland sea contain about one-tenth more mineral salts than those of the larger oceans1 and so it has long been the custom along the southern coasts of ,france to evaporate these waters for the production of common salt4 ,after this principal constituent is removed1 there remains a strong brine called bittern4 ,while experimenting upon this bittern1 ,balard was struck by a peculiar orange-red coloration of great intensity which appeared at certain stages of his work4 ,upon further study1 he was able to demonstrate that this color was due to an elementary substance hitherto unrecognized4 ,thus he had the felicity of securing for his name permanent renown as one of the few philosophers who have been able to detect a new member of that family of prime and fundamental materials from which is built the structure of the universe4 ,it has already been stated that the elements at present acknowledged are less than seventy in number1 and some of these were known to the ancients4 ,in some cases1 a single individual has been able to recognize several new ones3 thus ,scheele has already been mentioned as the discoverer of manganese1 barium1 and chlorine4 ,so it appears that of all the eminent men1 whose conscientious labors contribute to the building of the science of chemistry as a noble and harmonious edifice1 necessarily but few can possibly hope to attain the specially conspicuous honor of having their names forever associated with the first discovery of any of the primary elements4 ,an interesting story is told of the eminent ,german chemist1 ,justus von ,liebig1 in connection with this particular subject4 ,some years before ,balard's discovery there was sent to ,liebig1 from a ,german establishment where salt brines were employed1 a flask--whose contents were afterwards found to contain bromine1 or at least to be very rich in bromine--with the request that he examine the contents4 ,the general appearance of the substance seemed to be that of chloride of iodine1 and this circumstance led ,liebig to neglect making a more searching investigation4 ,after ,balard had published his discovery1 ,liebig perceived his own unfortunate oversight1 and occasionally1 of course not without some bitter regret1 he displayed to his friends this interesting flask1 to show them how one might fail to make a discovery of the first importance by reason of some trifling oversight4#d #d ,,schutzenberger1 ,,paul3 ,trait de ,chimie ,gnrale4 ,paris1 #ahhj4 i1 #cge4 ,distribution of ,bromine4 ,the name bromine is derived from a ,greek word 71 bromos1 a bad smell7 which suggests the very pungent odor of its vapor4 ,the substance occurs in the brine of the ocean and in that of mineral springs4 ,but of course it does not exist there in the uncombined form2 instead it is united with certain metals in the form of bromides4 ,in sea-water the principal bromide is bromide of magnesium 7,mg,br74 ,experimental ,preparation of ,bromine4 ,bromine may be prepared by anyone who is willing to take a little trouble4 ,place in any suitable glass vessel a small amount of manganese dioxide1 some potassic bromide 7commonly known as bromide of potassium71 then some water1 and finally a small quantity of chlorohydric acid4 ,bromine is almost instantly liberated1 and shows its presence by imparting to the liquid an orange hue4 ,if the vessel is covered lightly1 and then gentle heat is applied to it1 the bromine will be expelled from the liquid and will appear above it as a heavy vapor of a rich reddish-brown color4 ,some care must be exercised however in conducting this experiment1 since the vapor is very irritating to the eyes and also to the throat1 and it has a general corrosive effect upon most substances with which it comes in contact4 ,chemical ,properties of ,bromine4 ,in its chemical relations bromine shows very decided resemblances to chlorine1 having affinities for the same substances1 only less in intensity4 ,since its discovery it has found a considerable number of uses4 ,thus it is an important substance in the processes of photography2 and the enormous expansion and growth of this art within a very few years has required in the aggregate large quantities of bromine4 ,the considerable demand for bromine1 which at first increased its price1 has produced1 as might have been anticipated1 a stimulating influence upon the manufacture of it4 ,this has led to greatly increased production of the substance1 not only in ,europe but also in the ,united ,states4 ,in ,pennsylvania1 ,ohio1 and ,west ,virginia it has become an important article of manufacture2 in fact1 the ,united ,states now furnishes the largest proportion of the entire amount of the material produced in the world4 ,one of the most important compounds of bromine is that produced by its union with silver4 ,we refer to argentic bromide 7commonly called bromide of silver1 ,ag,br74 ,this substance may be easily produced by the following simple experiment4 ,illustration3 ,,fig4 #bd4--,louis ,jacques ,mand ,daguerre1 from whom the daguerreotype was named3 born at ,cormeilles1 7,france17 #aghi2 died1 #ahea4 ,to a solution of potassic bromide in water add a water solution of argentic nitrate2 a white1 or yellowish-white precipitate immediately appears4 ,the chemical change is represented by the following equation3 ,k,br ,ag,n,o ,one molecule of ,one molecule of ,potassic bromide1 ,argentic nitrate1 #aai #afi parts by weight4 parts by weight4 _/ #bhh ,ag,br ,,kno ,one molecule of ,one molecule of ,argentic bromide1 ,potassic nitrate1 #ahg #aja parts by weight4 parts by weight4 _/ #bhh ,this argentic bromide produced1 at first nearly white in color1 has the power of becoming black upon exposure to light1 and it is this important property which makes the substance suitable for use in the processes of photography4 ,again in the form of potassic bromide1 bromine has had a very wide and beneficent use as a remedial agent2 it is still largely used in the manufacture of the salt mentioned4 ,,reading ,,reference4 ,liebig1 ,his ,life-,work in ,chemistry4 ,hofman1 ,a4 ,w4--,jour4 of ,chem4 ,soc4 of ,london4 xxviii1 #ajfe4 ,illustration3 ,,fig4 #be4--,photographer at work in a room lighted through a window of red glass4 7,red glass cuts off the chief actinic1 or chemical1 rays of sunlight47 ,,chapter ,,xii4 ,,iodine4 ,iodine belongs to what may be called a chemical family1 the other members being chlorine and bromine4 ,all three of these elements are found in sea-water1 but in very different quantities4 ,thus chlorine is extremely abundant2 bromine is in the water in minute quantities1 while iodine exists there in amounts that are exceedingly small4 ,they all exist as salts1 of which of course chloride of sodium is by far the most abundant4 ,it has already been shown that bromine is obtained from sea-water1 after enormous amounts of the water have been concentrated by evaporation4 ,but iodine1 the third element of this group1 exists in sea-water in quantities so very minute that it cannot be extracted from it at any practicable cost4 ,even the concentration method1 just alluded to1 is not applicable in the case of iodine4 ,it happens however that sea-weeds have the power of extracting from sea-water even the exceedingly minute amount of iodine1 or of iodides1 that the water contains2 and moreover when sea-weeds are burned1 iodides are found in their ashes4 ,the ,discovery of ,iodine4 ,the discovery of iodine is associated with the history of certain of the most important and interesting products of the chemical arts4 ,it also has a striking connection with some of the political and military affairs in ,france1 and indeed in ,europe1 in the early years of the present century4 ,finally1 its great usefulness to mankind is in marked contrast with the misfortunes that overtook its discoverer4 ,illustration3 ,,fig4 #bf4--;,gathering the harvest of sea-weed for the manufacture of soda-ash4 ,the discovery of iodine is directly referable to the old soda industry4 ,the term soda is a general one1 and it was formerly used to include several different chemical compounds manufactured from the ashes of sea-weed4 ,decidedly the most important of these is sodic carbonate4 ,this substance has a well marked alkaline reaction1 and although not an alkali in the strictest chemical sense1 it is yet the principal product of that greatest of all the chemical industries known as the alkali trade4 7,see pp4 #id and #ii47 ,during the last sixty years1 and after many early trials and failures1 the production of the various alkaline compounds of sodium has risen to enormous proportions1 such that in ,england alone the daily product of sodic carbonate1 the principal one1 is probably more than two thousand tons4 ,this vast amount of alkali is consumed by civilized peoples in some of their most extensive industries such as the manufacture of soap and of glass1 and in many processes of bleaching4 ,the extension of these branches of business has of course gone hand in hand with the increased production of alkali4 ,indeed1 on the one side there has been a steady diminution in price1 and on the other a steady increase in consumption2 probably each circumstance may be considered as both cause and effect of the other4 ,prior to #agic however1 the demands for alkali--vastly smaller than to-day--were all satisfied by the material obtained from the ashes of marine plants4 ,thus along the coasts of ,great ,britain1 ,france1 and especially of ,spain1 sea-weed of various kinds was gathered as a very important harvest4 ,some of the weed was used as a fertilizer of the soil2 more was dried and burned for the sake of the ashes4 ,on the ,british coast the ash was known as kelp2 that produced on the coasts of ,normandy was called varech2 and that produced on the ,spanish coast went by the name of barilla4 ,illustration3 ,,fig4 #bg4--,varieties of sea-weed used to produce varech4 ,now one of the important indirect effects of the ,french ,revolution was that felt by the consumers of the old-fashioned alkali4 ,in #agic an embargo was put upon the supply of alkaline ashes1 such as kelp and barilla1 into ,france4 ,but the ,french demand for alkali1 not only for ordinary purposes1 but also for the production of the great amounts of saltpetre required for the manufacture of gunpowder1 was imperious4 ,the immediate effect1 therefore1 was to create the sudden development of a process called the ,leblanc method1 by which alkaline compounds of sodium are made from common salt4 ,notwithstanding the stimulus of the prohibitory embargo and the fostering help of the government of ,napoleon ,bonaparte1 the complexity of the ,leblanc process was such that it was slow in gaining a foothold as a practical industrial method4 ,but after its first successful establishment as a regular business and up to almost the present day the application of this process has continually widened1 and the method has held undivided sway in its important field4 ,in the year #ahaa ,bernard ,courtois1 a ,french chemist1 was engaged1 just as other manufacturers were1 in the production of nitrate of potash1 or saltpetre1 for use in gunpowder4 ,in the course of this work he employed soda obtained from varech4 ,in order to separate the alkali from the varech in a more refined condition the raw varech was subjected to a very careful purification4 ,at certain stages of his experiments ,courtois discovered that the addition of sulphuric acid gave rise to the production of a magnificent violet vapor4 ,he did not make the matter public however until late in the year #ahac1 when he brought the subject to the attention of ,sir ,humphry ,davy1 the distinguished ,english chemist1 who was then visiting ,paris4 ,the next year1 #ahad1 the substance was carefully investigated by ,gay-,lussac1 who gave to the world a very full description of its properties1 and who called it iodine from a ,greek word 71 ioeides1 violet colored71 suggesting the striking and characteristic color of its vapor4 ,the political events of #ahae ruined the business of ,courtois1 and he sunk into poverty from which he was not able to recover1 until finally he died in #ahch1 poor and almost forgotten1 leaving a widow who was forced to win her bread by the labor of her hands4 ,present ,sources of ,iodine4 ,although kelp1 varech and barilla are no longer used for the direct purpose of affording alkali1 they are still produced with a view to their yielding iodine4 ,on the rough and stormy coasts of ,scotland1 ,ireland1 ,france and ,spain1 large quantities of sea-weeds are cast ashore4 ,they are collected1 they are dried in the sun1 they are then burned1 and their ashes are employed--but principally in the manufacture of iodine4 ,thus on the coasts of ,brittany and ,normandy the occupation of collecting weeds occupies three or four thousand families for the larger part of the year4 ,experimental ,method of ,preparing ,iodine4 ,iodine may be prepared in a manner closely resembling the process already described for bromine2 that is1 by placing in a suitable glass vessel a small amount of manganese dioxide1 some potassic iodide 7commonly known as iodide of potassium71 then some water1 and finally a small quantity of chlorohydric acid4 ,iodine is almost instantly liberated1 and shows its presence by imparting to the liquid a brownish color4 ,if the vessel is covered lightly and then gentle heat is applied to it the iodine will be expelled and appear in the vessel above the liquid as a heavy vapor of a rich violet color4 ,this vapor readily condenses on the upper and colder portions of the vessel in the form of minute crystals of a color almost black4 ,this is almost precisely the method employed on the large scale for the production of iodine from kelp4 ,illustration3 ,,fig4 #bh4--;,changing iodine to a violet vapor by means of heat4 ,chemical ,properties of ,iodine4 ,the chemical characteristics of iodine are throughout closely allied to those of chlorine and of bromine1 only in general iodine may be said to have weaker chemical affinities than either of the other two4 ,illustration3 ,,fig4 #bi4--;,apparatus used in the manufacturing process for obtaining iodine4 ,the retorts ,c1 ,c1 are surrounded by sand 7sand-bath72 the heat drives iodine1 in form of vapor1 into the receivers1 ,a1 ,a1 where it solidifies4 ,iodine produces compounds of the same general type as the others1 and of this an example is found in argentic iodide4 ,the following method of producing it can be followed by almost any one4 ,prepare a solution of nitrate of silver in water1 and then add a water solution of potassic iodide2 a chemical change takes place1 with the production of a yellowish-white precipitate4 ,this precipitate is argentic iodide4 ,upon exposure to sunlight it readily changes in color1 becoming almost black4 ,this is an important characteristic and is made use of1 as is the same property possessed by argentic bromide and also by argentic chloride1 in the production of the photograph4 ,and while it is a fact1 and one well known1 that many of the salts of silver blacken more or less upon exposure to sunlight1 it is found that the chloride1 the bromide1 and the iodide1 have properties particularly fitting them for the purposes of photography4 ,in discussing bromine1 reference was made to the influence of the great expansion of the photographic business2 and this circumstance has stimulated the demand for iodine just as for bromine4 ,it was also pointed out1 that potassic bromide is an important remedial agent2 potassic iodide is likewise of great medicinal value4 ,starch as a ,test for ,iodine4 ,iodine1 when in the free or uncombined condition1 has a remarkable and very peculiar way of attaching itself to granules of starch4 ,this property may be demonstrated by a simple and attractive experiment4 ,thus if starch is boiled with water and then the hot mass is poured into cold water1 minute particles of starch distribute themselves through the liquid4 ,if to this liquid a very small amount of free iodine1 in the form of a solution1 is added1 the starch instantly takes on a deep blue color4 ,if to another portion of the same or similar starch suspended in water1 iodine is added in a combined form--that is as potassic iodide for example--absolutely no change of color is detected4 ,these two experiments show that the iodine only attacks starch when the iodine is free and uncombined4 ,,reading ,,references4 ,chlorine1 ,bromine1 ,iodine1 and ,fluorine4 ,mylius1 ,e4--,chem4 ,news4 xxxiii1 #bdd1 #bec2 xxxiv1 #e1 #ac1 #be1 #cc1 #de1 #ee1 #ff1 #gh1 #hf1 #aah1 #aci1 #adi1 #aff1 #ahj1 #ahh1 #aig1 #bae1 #bcc4 ,iodine1 ,manufacture of ,schmidt1 ,t4--,chem4 ,news4 xxxvii1 #ef4 ,stanford1 ,e4 ,c4 ,c4--,loc4 cit4 xxxv1 #agb4 ,,chapter ,,xiii4 ,,fluorine4 ,of ,fluorine it is necessary to made the remarkable statement that it has never been known to be produced isolated1 that is in a separate or uncombined form4 ,many experiments have been performed for the purpose of reaching this result1 and though none of these have resulted in the production of the element sought1 they lead us to believe that the element is a gas4 ,for1 if it were a solid or a liquid at ordinary temperatures1 it may be safely supposed that some processes that have been devised would be capable of producing at least a small quantity of the elementary substance1 and that from this the observer would be enabled to recognize and discover at least some of the properties of the fluorine itself4 ,properties of ,fluorine4 ,there are a number of compounds known whose various properties1 powers of chemical interchange1 and special molecular weights1 clearly point out the existence in them all of a certain peculiar element analogous in many respects to chlorine1 bromine1 and iodine4 ,to this element the name fluorine has been given4 ,although1 as before intimated1 it has not been known to have been obtained liberated1 its properties in these combined forms have been carefully studied and well made out4 ,thus1 like chlorine and its family associates it combines with hydrogen to form an acid1 fluohydric acid 7,h,fl71 properly comparable with the acids formed by the three elements last discussed3 ,chlorohydric acid1 ,h,cl4 ,bromohydric acid1 ,h,br4 ,iodohydric acid1 ,,hi4 ,it also combines with the metals to form fluorides4 ,the best example of these fluorides is that compound in which fluorine most commonly occurs in nature3 that is fluor-spar1 the mineral substance whose chemical name is calcic fluoride1 and whose composition is expressed by the formula ,ca,fl4 ,the property above all others that is characteristic of fluorine is1 however1 its striking affinity for silicon4 ,with this element it readily combines under almost any circumstances4 ,more wonderful still1 the compound produced with it is a gas4 ,now in general the compounds of silicon are solids4 ,these solids are many of them familiarly known in those materials which constitute the principal portions of the stable earth on which we tread1 of the rock beneath it and of the enduring mountain masses that here and there pierce through the soil and raise their crests above the general level4 ,the majority of these earthy and rocky substances are silicates4 ,it is apparent then that the compounds of silicon are types of solidity and stability4 ,they cannot be melted except in the most powerful heating appliances1 and the chemist can hardly imagine conditions such as would change them into vapor4 ,so then it seems strange and almost contradictory that fluorine should have the power of attacking compounds that seem to be the embodiments of permanency itself2--yet it readily does so4 ,thus if fluohydric acid comes in contact with silicon1 whether that substance is in combination as sand or as hard rocky minerals1 the fluorine atoms pluck out the silicon and then they fly away together in the form of gas or vapor4 ,again1 fluohydric acid may be spoken of as the unique agent that readily attacks glass and dissolves1 and even destroys1 this ordinarily unchangeable substance4 ,finally1 there may be added what can be said of no other element1 namely3 that fluorine is never known to form any compound with oxygen4 ,discovery of ,fluohydric ,acid4 ,it is not easy to refer the first knowledge of fluorine to any particular discoverer4 ,perhaps however renewed mention of the ingenious ,scheele is not out of place here2 for it seems to have been he who for the first time1 and as early as #agga1 recognized fluohydric acid as a special acid4 ,he called it fluoric acid1 but he did not obtain a correct idea of its composition4 ,scheele prepared the acid from a well-known mineral1 fluor-spar1 and by the addition of sulphuric acid4 ,this operation cannot be performed to advantage in a glass or porcelain vessel for they contain silicon1 and as has been suggested already1 silicious matters are freely attacked by the acid produced4 ,the decomposition therefore is commonly conducted in a retort of lead1 or in one of platinum1 and the acid produced is collected in a receiver1 also constructed of one of these metals4 ,illustration3 ,,fig4 #cj4--,platinum retort and receiver shown with its several parts separated4 ,the chemical change is represented by the following equation3 ,ca,fl ,h,,so ,one molecule of ,one molecule of ,calcic fluoride1 ,sulphuric acid1 #gh #ih parts by weight4 parts by weight4 _/ #agf #b;,h,fl ,ca,s,o ,two molecules of ,one molecule of ,fluohydric acid ,calcic sulphate #dj #acf parts by weight4 parts by weight4 _/ #agf ,ordinarily the product is a liquid1 and consists of water holding in solution the fluohydric acid 7,h,fl74 ,it is possible however to prepare the acid free from water1 and still in a liquid form4 ,but in this condition it is one of the most dangerous1 poisonous1 and corrosive substances known4 ,it produces painful burns if it falls upon the flesh1 and fatal results have been known to follow injuries received from it4 ,thus in #ahfi1 ,professor ,nickls1 an eminent ,french chemist1 died from injuries sustained by the accidental inhalation of fluohydric acid vapor1 while studying the properties of the substance4 ,etching ,glass by ,fluohydric ,acid4 ,the effect of fluohydric acid upon glass may be shown in attractive form1 and without much difficulty or danger1 by the help of a small dish of lead and a plate of glass to cover it4 ,these being provided1 the experiment may be conducted somewhat as follows3 ,melt a little beeswax upon the glass so that the wax may form a thin film upon one side of it4 ,then allow the wax to cool and harden4 ,next1 by use of any convenient pointed instrument1 draw some sketch or design deep in the wax--in fact1 to the surface of the glass4 ,next place some powdered fluor-spar in the leaden dish1 and add to it some concentrated sulphuric acid4 ,now cover the dish1 with the glass already prepared1 in such a way that the sketch or design is turned downward so as to receive the fumes of fluohydric acid as they rise from the mixture in the dish4 ,it is easily understood from what has been said already that the fluohydric acid will attack the glass1 carrying away some of its silicon in the form of gas or vapor4 ,as a result of this action1 minute channels are formed in the glass4 ,when the experiment is thought to be sufficiently advanced1 the wax may be removed from the plate by melting it off or otherwise2 thereupon it will be discovered that the glass has actually become etched or engraved by the fluohydric acid gas4 ,illustration3 ,,fig4 #ca4--,platinum retort and receiver shown as arranged for production of fluohydric acid 7,h,fl74 ,in #aghh ,puymaurin presented to the ,french ,academy of ,sciences such a glass plate1 upon which there was a beautiful fluoric etching representing ,chemistry and ,genius weeping at the tomb of ,scheele1 who had contributed so much to the history of fluohydric acid4 8,this work10 says ,hay1 8was of interest to the ,academy on account of the fitness of the subject as well as the elegance of its execution40 ,practical ,application of ,fluohydric ,acid4 ,fluohydric acid1 formerly a mere chemical curiosity1 has now become a familiar article upon the shelves of the druggists4 ,it is sold in gutta-percha bottles with rubber stoppers4 ,it is often used by jewelers to correct errors in the application of silicious enamels upon their work4 ,thus if the enamel has been incorrectly placed1 it may be removed by fluohydric acid and afterward a new portion may be introduced in the proper position4 ,again1 it is largely used in the decoration of artistic glass objects1 such as globes for gas chandeliers1 and the multitude of articles of table glass ware4 ,in engraving such objects1 they are first covered with a suitable varnish that will resist the fluohydric acid1 then the design is drawn through the varnish with a sharp needle2 afterward the article is exposed to the gas and etched in a manner similar to that already described4 ,illustration3 ,,fig4 #cb4--,leaden tray and glass plate4 ,the tray is intended to receive the materials for production of fluohydric acid2 the plate is represented as covered with a varnish1 through which a sketch has been drawn1 preparatory to etching4 ,,reading ,,references4 ,fluohydric ,acid4 ,gore1 ,g4--,jour4 of ,chem4 ,soc4 of ,london4 xxii1 #cfh4 ,fluorides4 ,fremy1 ,e4--,annales de ,chimie et de ,physique4 #c ,sr4 xlvii1 #e4 ,,chapter ,,xiv4 ,,oxygen4 ,oxygen may justly claim a high degree of importance as a subject for the study alike of the professional chemist and the casual reader4 ,this importance depends upon a variety of considerations4 ,among them are the surpassing abundance of the substance itself1 the great number of compounds into which it enters1 the activity of its chemical powers1 and finally1 the interesting circumstances under which its distinct recognition1 or1 as perhaps we may say1 its discovery1 was attained4 ,its great abundance has been pointed out already in the declaration that oxygen makes up1 by weight1 fully one-half of our terrestrial globe--including earth1 ocean and air4 ,the air is about one-fifth oxygen by weight2 all water1 wherever existing1 is sixteen-eighteenths oxygen by weight1 while quartz1 sand1 and other similar widespread and most commonly occurring mineral matters1 are a little more than one-half oxygen4 ,other solid matters than the rocks1 such as most parts of the material structures of animal and vegetable beings1 contain oxygen as an important constituent element4 ,while thus we have scanned the great multitude of substances spread immediately about us by the hand of nature1 and found oxygen in them all1 it is none the less true that oxygen is an important factor in artificial products--that is1 those resulting from man's manufacturing operations4 ,chemical ,activity of ,oxygen4 ,again1 oxygen plays a part of exceeding activity in some of the grandest chemical processes of nature and of the arts4 ,for example1 it is essential to the vital processes of all animals4 ,wherever a living being inhales the breath of life1 whether from the fresh air of the mountain tops1 or from the populous streets of the swarming metropolis1 or from the solitary deck of the bark that creeps with the ocean's currents2 or wherever the humbler servants of man's table find their way through unexplored depths of the ocean and pluck from its waves the modicum of life-giving gas dissolved within them2 there is this wonderful agent1 which has no substitute1 sustaining by active processes truly chemical1 that vitality of man or of beast which gives to nature its forms of highest beauty and most admirable intelligence4 ,again1 oxygen is the necessary agent in all ordinary combustions4 ,so wherever a faggot1 glowing beneficently in a sparsely peopled forest1 helps to sustain man's vital spark2 or1 where in a highly civilized community1 the fires on the altars of modern industry draw from the flinty rocks the metals that serve to give employment to millions of children of toil2--there oxygen is ever active1 the true supporter of the combustion of all those flames which in the past have served as signs of life and civilized activity1 and which are still the best symbols of vitality and intelligence4 ,the ,discovery of ,oxygen4 ,the first discovery of oxygen is usually attributed to ,dr4 ,joseph ,priestley1 an ,english clergyman and student of natural science4 ,he lived in a time when men's minds all over ,europe were strongly drawn toward the pursuit of chemical knowledge4 ,in fact1 at almost the same moment that ,priestley was enthusiastically conducting his experiments1 ,scheele was also producing oxygen in his apothecary's chamber in ,sweden4 ,and the brilliant ,lavoisier1 prominent among the men of distinction who thronged the gay capital of ,france1 was also working in the same direction2 it was he1 who said about oxygen in one of his own chemical works3 8,cet air que nous avons decouvert presque en mme temps1 ,dr4 ,priestley1 ,m4 ,scheele et moi10 so that he is sometimes declared by his enthusiastic countrymen to be entitled to the merit of the earliest discovery of this most magnificent of elements4 ,illustration3 ,,joseph ,priestley1 ,born near ,leeds1 ,england1 ,march #ac1 #agcc2 died in ,northumberland1 ,pa41 ,february #f1 #ahjd4 ,priestley's life included ample materials for a romance4 ,on the one hand1 the ingenious discoverer in physics and chemistry and the friend of that ,benjamin ,franklin--who was then minister at the brilliant court of ,france from a handful of colonies that appeared capable of being plucked up by the roots1 but were instead destined to grow to an unrivalled empire--himself a figure in a romance2 and1 on the other side1 a preacher to a dissenting congregation2 a victim of public odium for his liberal opinions on religious and political subjects2 his house set on fire by a mob1 his apparatus wrecked1 his library cast to the winds2 finally1 an emigrant with his wife and children to an almost unknown village in ,pennsylvania1 whose little burial-ground still gives his bones repose2--these are but brief suggestions of the trials of this perturbed spirit1 in his life 8sadly driven about and tossed10 now cherished as one of those who in the realm of thought has made no mean contribution to the glory of the ,english name4 ,dr4 ,priestley prepared oxygen from red precipitate of mercury1 a substance now designated by the name mercuric oxide and by the formula ,hg,o4 ,heating this substance in a receiver and by means of a burning glass or lens1 he observed that a peculiar kind of air was evolved4 ,he further discovered that this air had an unusually stimulating influence upon burning bodies1 and was well suited for the respiration of living animals4 ,priestley's prime experiment was performed on the first day of ,august1 #aggd1 a date which may be accepted as almost the birthday of modern chemistry4 ,like many other great discoverers1 ,priestley was1 to a certain degree1 anticipated4 ,thus a certain ,john ,mayow1 an ,english physician1 fully a hundred years before the time of ,priestley's experiment1 enunciated the doctrine that the atmosphere contains an air1 in a certain sense the essential food of animal life and of flame4 ,but these wonderful views of ,mayow1 brought forward too early for the state of thought at his time1 lay dormant and unproductive for an entire century4 ,first ,method of ,preparing ,oxygen4 ,oxygen may be prepared in many ways1 but only two need receive attention here4 ,the first method is ,priestley's4 ,if the red oxide of mercury is heated over a powerful gas flame and in a tube of not easily fusible glass1 the oxygen passes from the metal and may be carried by any small conducting tube into a convenient receiver filled with water and standing in the pneumatic trough4 ,if the gas so collected is tested by means of a candle1 having only a spark on its wick1 the oxygen is readily recognized by the fact that the taper promptly bursts into a full and brilliant flame4 ,this method is of historical interest chiefly1 though it may well attract some attention from the simplicity of the chemical change involved4 ,thus this change is represented by the following equation3 #b;,hg,o heated ,o #b;,hg ,two molecules of ,one molecule of ,two atoms of ,mercuric oxide1 ,oxygen1 ,mercury1 #dcb #cb #djj parts by weight4 parts by weight4 parts by weight4 _/ _/ #dcb #dcb ,a word about the pneumatic trough is not out of place here1 because this useful contrivance was the invention of ,priestley4 ,the name may be appropriately applied to almost any vessel of water in which may stand the open mouth of a bell-glass suitable for containing gas4 ,the water serves at once to seal the mouth of the jar1 and also to afford a material through which the exit tube of an appliance may be dipped1 and through which also the gas from the tube may freely and conveniently flow into the bell-glass4 ,before ,priestley's time gases had been collected in bladders or varnished bags1 but the new contrivance furnished a much superior means of detecting small quantities of gas and working with them4 ,second ,method of ,preparing ,oxygen4 ,the second method1 and that oftenest pursued1 employs a salt not known in ,priestley's time4 ,this salt is called potassic chlorate and is represented by the formula ,k,cl,o4 ,this substance1 when heated1 evolves a large amount of oxygen1 but it does so with almost explosive violence4 ,the chemical change is represented by the following equation3 #b,k,cl,o heated #b,k,cl #c,o ,two molecules of ,two molecules of ,three molecules of ,potassic chlorate1 ,potassic chloride1 ,oxygen1 #bde #adi #if parts by weight4 parts by weight4 parts by weight4 _/ _/ #bde #bde ,on the other hand1 if the potassic chlorate is mixed with about one-third of its weight of the earthy mineral known as black oxide of manganese1 7but called by the chemist1 manganese dioxide17 the mixture when heated evolves oxygen more slowly and continuously than the chlorate alone--and it does it at a lower temperature4 ,strangely enough however1 the manganese dioxide appears to take either no chemical part in the operation or else only a very obscure one4 ,indeed1 some other oxides will serve the same purpose1 while they likewise appear to undergo no chemical change4 ,in this method1 as in the other1 the oxygen gas produced may be collected in a bell-glass over the pneumatic trough1 and afterwards its nature may be demonstrated as before by means of the taper having a spark upon it4 ,the ,properties of ,oxygen4 ,it has been the custom of chemists to say of oxygen that it is a permanent gas4 ,the force of this expression is found in the fact that until recently all attempts to liquefy it were futile4 ,but recent experiments1 with apparatus capable of subjecting it at once to more intense cold and to greater pressure than were ever before employed1 seem to demonstrate that it will turn to a liquid when these conditions are carried to a sufficient extreme4 ,that oxygen is colorless and odorless appears plain from the properties of the atmospheric air throughout which this gas is thoroughly diffused and intimately intermingled1 although it constitutes but one-fifth of it4 ,chemical ,properties of ,oxygen4 ,illustration3 ,,fig4 #cd4--,the rays of sunlight concentrated1 by a lens1 upon a diamond placed in oxygen gas1 with a view of proving the combustibility of the gem4 ,of the chemical powers of oxygen the most striking and important seems to be its marked tendency to combine with other elementary substances4 ,in many cases this combination does not commence except when the substances are heated4 ,thus the noble buildings of a city are every day and every night continuously and harmlessly bathed within and without by that same oxygen1 that1 in time of conflagration1 is ready chemically to combine with their elements and as a result to reduce the metropolis to ashes4 ,but such combination1 once inaugurated1 often itself affords sufficient heat not only to make the process continue1 but also to generate that flame or fire which is the token of what is ordinarily called combustion4 ,in this view1 oxygen is often spoken of as a supporter of combustion4 ,that this property1 known to be associated with the atmospheric air1 does in fact reside in the oxygen of it1 is to some extent proved by the more rapid and brilliant combustion of the candle in pure oxygen4 ,another interesting experiment is performed when a piece of charcoal1 which may be supported on a wire1 is burned a little so as to acquire a spark1 and then is dipped in oxygen gas4 ,the single coal would soon cease to burn in atmospheric air1 but it burns readily and brilliantly in pure oxygen4 ,even the diamond1 the most compact and imperishable form of carbon known1 may burn in pure oxygen gas just as the most humble piece of coal does1 and the relationship of the gem to the commonplace fuel is proved by this experiment4 ,illustration3 ,,fig4 #ce4--,the burning of a spiral of iron wire in a jar of oxygen gas4 ,still another experiment in the same direction may be conducted with sulphur4 ,for this purpose a fragment of sulphur set on fire may be dipped in a jar of pure oxygen4 ,the sulphur burns with vastly increased rapidity and with a violet flame much more brilliant than that of sulphur burning in air4 ,again1 some substances not ordinarily considered combustible will burn in oxygen gas4 ,thus a bundle of iron wire1 to which a little lighted chip is attached1 itself takes fire and burns brilliantly when dipped into oxygen gas4 ,the ,products of ,combustions in ,oxygen4 ,as a necessary result of the combustion of substances in oxygen there are produced a multitude of compounds called oxides4 ,this is true of the candle1 which consists mainly of carbon and hydrogen4 ,when the candle burns1 these two substances change into oxides4 ,the carbon produces carbon dioxide1 whose formula is ,,co1 and which is familiarly known as carbonic acid gas4 ,this oxide1 it is true1 is not easily recognized by the ordinary observer because it is an invisible gas1 but the chemist can prove that it is in fact the product of this combustion4 ,at the same time the hydrogen produces an oxide whose formula is ,h,o and which will be recognized as the chemical expression for water4 ,and so water is in fact produced1 though in the form of vapor1 by the burning candle4 ,charcoal is composed almost entirely of what the chemist calls carbon1 and when it burns it produces the oxide called carbon dioxide 7,,co74 ,this is the same invisible gas that has already been declared to be produced when the carbon of the candle is burned1 and in this case as in the other it is easy for the chemist to prove its presence4 ,in case of carbon1 the chemical change is represented by the following equation3 ,c ,o ,,co ,one atom of ,one molecule of ,one molecule of ,carbon1 ,oxygen1 ,carbon dioxide1 #ab #cb #dd ,parts by weight4 ,parts by weight4 ,parts by weight4 _/ _/ #dd #dd ,and likewise when iron is burned1 there is formed an oxide whose composition is expressed by the formula1 ,fe,o2 7to this substance the chemical name ferroso-ferric oxide is applied74 ,so when sulphur is burned1 sulphur dioxide is formed 7,,so74 ,in this case the chemical change is represented by the following equation3 ,s ,o ,,so ,one atom of ,one molecule of ,one molecule of ,sulphur1 ,oxygen1 ,sulphur dioxide1 #cb #cb #fd ,parts by weight4 ,parts by weight4 ,parts by weight4 _/ _/ #fd #fd ,compound of ,oxygen with ,hydrogen4 ,illustration3 ,,fig4 #cf4--;,hydrogen gas1 generated by use of zinc and sulphuric acid1 is then passed through a drying tube containing calcic chloride 7,ca,cl74 ,by the act of combustion the union of the dried gas with oxygen of the air produces drops of water4 ,it has already been shown that the hydrogen escaping from a suitable tube may be lighted in the air4 ,if the burning jet is introduced into oxygen gas the same combustion proceeds1 only with greater energy4 ,in either case there is produced a compound of hydrogen and oxygen4 ,this compound is represented by the formula ,h,o1 a formula representing no other than the familiar substance water4 ,at the moment of combustion of hydrogen very great heat is generated4 ,in fact1 a pound of hydrogen1 upon burning in pure oxygen1 yields about four times as much heat as a pound of pure carbon does in burning under the same favorable conditions4 ,indeed1 the pound of hydrogen1 when in combustion1 yields more heat than a pound of any other substance known4 ,on account of this heat the water resulting from the burning hydrogen at first floats off in the air in the form of vapor2 but if the hydrogen flame is brought in contact with some cooling surface1 the water formed condenses in drops upon it and thus it may be readily recognized as in its ordinary form4 ,a great multitude of experiments show that the composition of water is as follows3 ---------------------------------------- ----------------------- ,,water ,,is ,,made ,,up ,,by ,,the ,,union ,,of1 ---------------------------------------- -------------------- ,,parts ,,by ,,weight1 ,,parts ,,by ,,bulk1 ,,atoms4 ---------------------------------------- -------------------- ,,hydrogen1 #b #b #b ,,oxygen1 #af #a #a ---------------------------------------- -------------------- ,the composition of water1 as displayed in the foregoing table1 has been demonstrated by analysis1 this word meaning 8the process of taking apart40 ,thus by chemical influences a portion of water may be subdivided into its constituents and their amounts determined4 ,on the other hand the composition of water has also been made out by synthesis1 this word meaning 8the process of putting things together40 ,in this latter case1 by putting together what are believed to be the proper proportional amounts of hydrogen and oxygen to form water1 and then upon using some suitable means for bringing these things into a state of true chemical combination1 it has been found that they do combine in fact to form water and in the proportions already given in the table4 ,the ,compound ,blowpipe4 ,the fact of the enormous heat developed when hydrogen burns1 was known long ago1 and it gave rise to the invention of a contrivance for utilizing it4 ,this has taken the form of the apparatus called the compound blowpipe1 also the oxy-hydrogen blowpipe4 ,illustration3 ,,fig4 #cg4--;,apparatus for analysis of water by use of the galvanic battery4 ,illustration3 ,,fig4 #ch4--;,apparatus devised by ,dumas for determining the composition of water4 ,this blowpipe1 as usually constructed1 has a single jet or tip--to which there is conveyed by separate tubes1 on the one hand oxygen1 on the other hand hydrogen4 ,the gases1 when lighted1 give rise to a flame of but little luminous power but of intense heating power4 ,many difficultly fusible metals1 such as iron for instance1 melt like wax before it1 while others1 like lead and zinc1 boil and vaporize beneath its fervent breath4 ,it must not be looked upon however as a mere chemical toy2 it has some uses in the arts4 ,of these one of the most prominent is its application to the melting and refining of the ores and alloys of platinum1 substances which no ordinary furnace can liquefy4 ,for purposes of this sort1 a special furnace or crucible must be provided1 and it must be constructed of some substance that is itself practically infusible4 ,such a material is found in quicklime 7calcic oxide1 ,ca,o71 for this substance does not melt under the influence of any known contrivance for producing heat4 ,moreover it does not conduct heat rapidly1 and thus any heat applied to the metal within1 is not subject to serious loss by being conducted away through the walls of the vessel4 ,for melting platinum then a crucible constructed of quicklime1 and having a cover of the same material1 is employed4 ,a stream of burning gases from a compound blowpipe is forced through an aperture in the crucible cover in such a way as to fall on the metal to be melted4 ,illustration3 ,,fig4 #ci4--;,flame of the oxy-hydrogen blowpipe directed upon a crucible in a furnace of lime4 ,the ,calcium ,light4 ,another interesting application of this blowpipe is found in the lime light1 an appliance also known as the calcium light and sometimes as the ,drummond light4 ,in this apparatus1 whatever may be its particular form1 the stream of burning gases is directed upon a small block or cylinder of lime4 ,of course the block becomes highly heated1--in fact it assumes a white heat1 without melting2 and while at this temperature it gives out a dazzling light4 ,this light has been utilized by architects and engineers for carrying on important constructions during the darkness of night4 ,it is also often used in some of the finer forms of the magic lantern1 as for example in the various stereopticons used in illustrated lectures4 ,so numerous are the uses of the calcium light in large cities that it has become a regular industry there to furnish the oxygen and hydrogen gases in separate iron cylinders or cans1 into which they are pumped under great pressure4#e 7,it is true that illuminating gas is sometimes substituted for hydrogen with decided economy in cost1 and yet without serious loss of illuminating power47 ,when the cylinders are in use the stop-cocks are slightly opened1 and the gases are under sufficient pressure to flow to the top of the blowpipe as freely as can be desired4 ,illustration3 ,,fig4 #dj4--;,drummond light1 or calcium light4 ,the flame of the oxy-hydrogen blowpipe directed against a block of lime renders the latter intensely luminous4 #e ,,dangerous ,,explosibility ,,of ,,mixtures ,,of ,,oxygen ,,and ,,hydrogen4--,at this point a warning should not be omitted1 for mixtures of oxygen and hydrogen gas1 whether produced purposely or by accident1 are capable of very dangerous explosions4 ,even a soap bubble1 inflated with the mixed gases1 and then lighted with a torch1 explodes with tremendous violence and a loud report4 ,this result is all the more wonderful when the extreme thinness and weakness of the filmy confining envelope is considered4 ,such explosions are in entire harmony with the various statements already made4 ,for when the two gases combine1 the intense heat then generated gives rise to a momentary but enormous expansion of the vapor of water produced by the combustion4 ,the greatly expanded vapor immediately strikes the air a sharp and violent blow4 ,in another instant however the vapor suddenly cools and condenses to an exceedingly minute drop of liquid water4 ,immediately upon this effect1 the air that was previously forced outward immediately falls into the vacancy left1 and now a second blow results4 ,it is these two violent shocks the one following the other in almost instantaneous succession1 that produce the report2 and to the same causes must be referred the terribly destructive results of the accidental explosion of considerable quantities of the mixed gases4 ,it is plain therefore that all contrivances1 destined to employ these gases in close proximity1 must be handled with great caution when ready for use4 ,oxygen as ,related to ,combustions in ,general4 ,but oxygen is prominent in many other combustions besides that of hydrogen4 ,of course the best known and most common are those in which the ordinary forms of fuel are the things burned4 ,here generally the principal constituent of the combustible material is carbon4 ,oxygen as ,related to ,animal ,respiration4 ,oxygen performs also one of its most important offices in connection with the process of animal respiration4 ,in the fulfillment of this mission no element is known that can in any way act as a substitute4 ,the gas1 which is to serve as the breath of life for the humblest as well as the most exalted individuals of the animal creation1 must possess a combination of qualities truly marvellous when residing in a single substance4 ,even a brief description of the ways in which it discharges this delicate and manifold duty ought to substantiate the general proposition4 ,oxygen is qualified to sustain respiration by virtue of the exceeding abundance of the atmospheric air1 an abundance such that it extends above our heads a distance of forty thousand times the height of a man4 ,nor are the denizens of the sea forgotten1 for oxygen possesses such capacity for dissolving in water that there exists1 absorbed in the liquid of the rivers and oceans1 enough of this vital gas to furnish breath for all the finny tribes4 ,again1 the oxygen1 so violent in its combinations1 is yet bland enough to pass through all the delicate passages leading into the lungs without exciting the throat to the slightest cough2 to filter through the fine membranes of the lungs without doing an injury2 to saturate the blood1 and to flow to every tissue and cell of the body1 and not only do no harm but everywhere accomplish a reviving work4 ,it performs throughout the animal frame a well regulated but no inconsiderable combustion4 ,indeed the body of a living creature may be properly looked upon as a kind of furnace1 taking in air whose oxygen shall sustain the combustion of worn-out parts4 ,nay more1 these as they burn do in their very death make as a final contribution the gift of that warmth and glow which maintains the animal temperature at the vital point4 ,while carrying out the important functions just referred to1 oxygen produces several gaseous substances1 each of which1 as if under the constant direction of an ever watchful barometer1 maintains its proper bulk and pressure1 so as to do no injury to the most delicate capillary of a vein or to the tender walls of the smallest chambered cell of the lungs4 ,with each breath exhaled from the system1 the blood1 and thence the lungs1 discharge the gaseous products of the combustion already described2 plainly they do it somewhat in the same manner as a chimney does in its proper action1 only the lungs do their work in a far more perfect way4 ,the parallelism is not strained here1 for the burning of the animal tissue in the body gives rise principally to the production of the gas called carbon dioxide and the vapor of water1 just as when a faggot burns in the chimney-place1 the carbon and the hydrogen of the wood oxidize into the self-same products1 both of which are wafted up the flue and out into the great ocean of atmosphere beyond4 ,,reading ,,references4 ,gases1 ,liquefaction of ,cailletet1 ,m4--,annales de ,chimie et de ,physique4 #e ,sr4 xv1 #acb4 -------- ,chem4 ,news4 xxxvii1 #aa4 ,coleman1 ,j4 ,j4--,chem4 ,news4 xxxix1 #hg4 ,pictet1 ,r4--,annales de ,chimie et de ,physique4 #e ,sr4 xiii1 #ade4 -------- ,chem4 ,news4 xxxvii1 #a1 #bc1 #hc4 ,roscoe and ,schorlemmer4--,chemistry4 ,new ,york4 #ahgh4 ii1 pt4 ,,ii1 #eaf4 ,schutzenberger1 ,p4--,trait de ,chimie ,gnrale4 i1 #be4 ,priestley1 ,joseph ,brougham1 ,h4--,lives of ,men of ,letters1 etc4 p4 #djb4 -------- ,amer4 ,chemist4 iv1 #cfb-dda2 v1 #aa-ce1 #dc1 #baj4 ,,chapter ,,xv4 ,,water4 ,as the most prominent compound of oxygen1 water may properly receive the reader's attention at this time4 ,he who stands upon a high cliff and looks out upon the ocean1 experiences as one of his strongest impressions that of the boundlessness of the expanse4 ,and it is true that the area of terrestrial waters is very wide1 for in the aggregate their waves cover more than three-fourths of the earth's surface4 ,but while their superficial extent is so great1 their depths are relatively but small4 ,when compared to the diameter of the earth the deepest ocean seems shallow indeed4 ,if the waters of the oceans were dried up or otherwise wiped away1 the roughness of the dry globe would be less relatively than the roughness of an orange4 ,in fact the total amount of water actually existing upon the earth's surface is less--relatively to the entire mass of the globe--than the amount that would remain on an orange after dipping it into a basin of water and then withdrawing it4 ,notwithstanding these facts1 the amount of water is so vast in proportion to the littleness of human beings1 and it has taken so prominent a part in the phenomena observable by man1 and it has been such a powerful agent in the geological eras of the past1 that it is not surprising that its properties and history have excited the interest of students and thinkers of all times4 ,in the light of modern chemical knowledge too1 its various offices create an admiration that is heightened1 the more they are considered4 ,the chemical history1 the characteristics1 the properties1 and the uses of water1 all these are important chemical topics2 when one considers further1 the varied forms and uses in which this familiar substance is employed in nature and in the arts1 a subject is suggested that might well furnish material for a volume4 ,plainly then only a few of its more striking adaptations can be discussed here4 ,illustration3 ,,fig4 #da4--;,egyptian ,water-carrier4 ,importance of ,water to ,living ,beings4 ,to living animals and plants water appears to be absolutely indispensable4 ,the reason for this is found not only in the fact that water forms a necessary constituent part of most living beings1 but also because it serves as a sort of vehicle by virtue of whose properties the vital processes are conducted and through which the vital currents flow4 ,it is easy to understand that if the atmospheric air1 which lies wrapped about our globe like a thin veil1 were suddenly wafted away1 animal life would be instantly extinguished4 ,now1 water is not less essential than air4 ,banish water from the earth1 and the life of all animal and vegetable beings would instantly take its flight4 ,for the blood1 that living tide which courses through the natural gates and alleys of the body1 contains water to the extent of nearly seven-eighths of its weight4 ,again pure1 unadulterated milk1 rich as it is in solid food materials dissolved or suspended within it1 contains not far short of #ij per cent of water4 ,and further1 an examination of vegetable products reveals in them a preponderance of water such as would not at first be suspected4 ,thus the following brief table represents facts so surprising that it is at first difficult to accept them3 ,apples contain about #hj per cent of water4 ,turnips 0 0 #ij 0 0 0 0 ,cucumbers 0 0 #ig 0 0 0 0 ,finally as an extreme example among the kingdoms of life it may be mentioned that some forms of jelly-fish1 as taken from their appropriate home in the ocean1 have been found to contain not less than #ii _/ per cent4 of water4#f #f ,,cooke1 ,,josiah ,p43 ,religion and ,chemistry4 ,new ,york1 #ahfd4 p4 #adh4 ,the extraordinary and incredible proportion of water in living beings is associated with the numerous1 varied1 and even apparently contradictory offices to be performed by it1 and the fitness of water to fulfil these requirements is referable further to the curious and interesting properties with which it is endowed4 ,but it is so familiar to every one and so bland in its action in its relation to most well-known substances1 that the ordinary observer fails to recognize these properties and their marvellous adaptations4 ,one of the properties most appropriate for presentation in this connection is the power water possesses of dissolving gases4 ,it is capable of storing up within itself1 concealed from human view1 almost every gas with which it comes in contact4 ,it displays this power upon the atmospheric air1 not only in its better known relations to man and the higher animals1 but also as respects the humbler population of the globe4 ,it will be seen by-and-by that the air consists in the main of a mixture of two gases very different in their properties4 ,one is oxygen1 the sustainer of animal respiration2 the other1 nitrogen1 the inactive substance existing in the air as a mere diluent of the active oxygen4 ,now water possesses a very curious relation to these gases2 it naturally dissolves a larger proportion of oxygen than of nitrogen4 ,by reason of this property it acts upon the atmospheric air with a selective effect highly suggestive of intelligent plan4 ,for the gas it selects to dissolve in larger proportional quantity is oxygen1--the one absolutely needed to take the principal part in supporting the respiration of the countless millions of fishes that make their natural homes in all great bodies of water4 ,illustration3 ,,fig4 #dc4--;,arctic explorers employing dynamite to open a channel through the ice4 ,terrestrial ,circulation of ,water4 ,water is the chief liquid of the great globe itself4 ,and it carries on here a continued and beneficent circulation which may be properly likened to that of the living animal and plant1 except that it proceeds on the cosmical scale4 ,this circulation may be described as starting in the depths of the ocean1 where permanent currents are constantly flowing in certain directions4 ,these contribute to make the seas the highways of navies even more completely than they would be if the waters were always at rest4 ,a yet more striking circulatory movement is that initiated by the volumes of moisture which rise by constant evaporation from the temperate as well as the tropical seas4 ,this water1 ascending into the higher atmosphere1 is carried by currents of the air hither and thither and over the land1 where by mountain ranges or other natural means adequate to this purpose1 it becomes precipitated into a solid or liquid form4 ,in this condensed form it is recognized as beneficent when it is in cloud masses which delight mankind with the purity of their fleecy whiteness1 or the beauty of their gorgeous coloring as well as when it is in the form of showers which refresh the thirsty earth1 or as the snow which protects it4 ,the rain and snow supply the numberless rivulets that contribute to make up rivers1 and these flow joyfully to the ocean and1 mingling in its waters1 return to the source from which they came4 ,thus has been pictured in brief an outline of the circulation previously suggested4 ,water in the ,solid ,form4 ,again1 certain properties of water in the solid form are worthy of presentation4 ,perhaps it is not inconsistent with the truth to say that they are even more plainly beneficial4 ,thus in the form of snow1 water appears at first sight to be an emblem of cold4 ,but when it falls upon the earth it becomes a mantle or coverlet1 which protects the soil from the chilling effects of the wintry season and from that rapid loss of heat by radiation off into space which the fields would suffer without this protective coating4 ,and so ice1 as it forms on the surface of lakes and ponds1 manifests several remarkable properties4 ,of these only two will be discussed here4 ,they are both due to its power of expanding at the moment of solidification4 ,most persons make acquaintance with this characteristic of water by the inconvenient bursting of pitchers and pipes1 recognized as a disagreeable attendant upon the winter's cold4 ,when looked upon with more fully instructed eyes1 however1 it is discovered to be one feature of a remarkable system which results in great benefit to the inhabitants of the earth4 ,for it is plain that as water in freezing expands1 it thereby becomes relatively lighter4 ,on this account ice floats in water1 whereas solid substances generally sink in liquid matters of their own kind4 ,now the ice formed upon lakes in the winter1 stays at the top and thus protects the water below from the chill of the colder air2 so it prevents the lakes from becoming uninhabitable to the fish4 ,the same property prevents a lake from becoming a mass of solid from the bottom upwards1 as would be the case if the ice upon freezing went to the bottom4 ,the summer's sun would hardly be capable of thawing the solid masses so formed4 ,this same curious fact of the expansion of ice at the moment of its formation contributes to the fertility of the soil4 ,thus the water that penetrates the crevices of rocks1 expands upon freezing1 chipping off those rocks1 in fact pulverizing them little by little1 and so conveying fresh and valuable materials to the earth's soils4 ,illustration3 ,,fig4 #db4--,water in the form of cumulus clouds4 ,water as ,affecting ,climate4 ,further1 the relations of water to heat are very interesting4 8,the general aqueous circulation of the earth is a great steam-heating apparatus1 with its boiler in the tropics and its condensers all over the globe4 ,the sun's rays make the steam4 ,and wherever dew1 rain or snow fall1 there heat1 which came originally from the sun1 and which has been brought from the tropics concealed in the folds of the vapor1 is set free to warm the less favored regions of the earth4 ,this apparatus in nature1 although so much simpler and working without pipes1 iron boiler or radiators1 is exactly the same in principle as the steam heater which may be seen at work in almost every large factory40#g ,in other words1 when water is changed into vapor in the tropics1 heat is not only requisite to the operation1 but a definite quantity of heat is actually stored up within the vapor so produced4 ,on the other hand1 whenever in some cooler parts of the globe this same portion of vapor condenses into the form of liquid1 that heat that was stored within it at the tropics is immediately evolved and contributes something to the warmth of the region where condensation takes place4 ,nay more1 if the water1 instead of falling as rain1 falls as snow a still larger amount of heat is by this means given out into the atmosphere4 ,this last statement is insensibly substantiated by the expression often heard in winter1 8the weather is too cold for snow40 ,this common expression1 translated into scientific language1 means 8the air does not possess that amount of warmth that it would manifest if snow were now condensing in the upper air and were ready to fall40 #g ,,cooke1 ,,josiah ,p43 ,religion and ,chemistry4 ,new ,york1 #ahhd4 p4 #ace4 ,it is not only with respect to those changes taking place when the vapor of water changes to the liquid or the solid form that its heat relations are beneficial to mankind4 ,no lake can change one degree in temperature--that is1 grow warmer or cooler--without at the same time exercising a contrarywise influence upon the air about it1 and thus a regulating one4 ,in explanation of this declaration the following statements may be made3 ,when1 in the intensely hot days of summer1 a lake or any mass of water become influenced by the high temperature1 of course its waters become warmer4 ,but it is a curious fact that it takes more heat to raise the temperature of water one degree than it does to raise the temperature of the adjoining land one degree--or in fact to raise any other substance known1 one degree4 ,thus it appears that a given amount of heat applied in a summer day to a lake will be absorbed within the waters of that lake without raising the temperature of those waters to the extent that might be expected4 ,so then in hot weather the lake becomes an equalizer of temperature with a tendency in the opposite direction1 that is to cool the air about it4 ,now in cold weather it becomes equally beneficial1 only1 as might be expected1 in the opposite direction4 ,thus the store of heat retained by the liquid water is given out as the lake cools4 ,for just as the water in order to rise one degree in temperature requires1 and indeed absorbs1 more heat than any other substance known1 so naturally the same water1 in cooling one degree in temperature1 freely gives out the amount of heat it had previously stored within itself1 which1 as has been said is greater than that stored up by any other substance known4 ,water as a ,working ,contrivance4 ,when the moisture of the tropical oceans is taken up into the air by evaporation1 the sun has thereby done a truly stupendous amount of work4 ,for has it not lifted up high into the atmosphere an enormous weight of this liquid material8 ,now as the vapor is wafted over the land preparatory to falling as rain1 it has acquired a position in which it may do a great amount of work for human uses2 for every rain-drop1 falling from its lofty position in the air1 acquires thereby a momentum which represents a quantity of force1 minute in each individual case but truly vast in the aggregate4 ,of this sum total but a small portion is employed for man's industrial uses2 only a minute fractional part is harnessed to the wheels that grind his food or weave his clothing or transform the trees of the forest into his habitations2 yet the amount he does so employ--compelling it to do his work for him--represents an enormous total quantity4 ,all this work done1 as well as all that might be done1 by the vast quantities of water allowed to escape and violently run to waste1 is referable back again to the sun of the tropics1 which has been enabled1 by reason of the wonderful properties of water1 to store up all this power within it4 ,in view of what has been said1 the sun and the water of the tropics may be compared not inappropriately to the chief artificial contrivances used in modern times for generating and applying mechanical power--boiler and engine4 ,as an ordinary steam-boiler imparts to water the expansive and working power of steam1 and again the ordinary steam-engine utilizes this steam power so that it may be directly applied to the labor of man's workshops1 so the sun of the tropics lifts the water of the ocean high up into the air1 and thus may be likened to the boiler2 while the rapidly running brooks may fitly represent an engine in motion1 ready to actuate any machine to which by proper appliances it may be attached4 ,,chapter ,,xvi4 ,,sulphur4 ,sulphur1 in its aggregate in the earth is by no means an abundant element4 ,thus its quantity is far inferior to that of oxygen1 as is strikingly illustrated by the diagram already presented4 7,see page #af47 ,yet sulphur was recognized by human beings thousands of years before oxygen1 which it has already been stated was discovered in #aggd4 ,the comparative lateness of the discovery of this latter element1 now known to be that one which predominates largely over all others in the earth1 is due partly to the fact that free oxygen almost invariably exists in gaseous form and that the idea or notion of gas is one of recent growth4 ,the fact that sulphur was recognized so much earlier is due to many circumstances4 ,first3 ,it is found in the earth in the solid condition--a form at once tangible and easy of recognition4 ,second3 ,its yellow color helps to render it noticeable4 ,third3 ,it exists in the earth in countries which have long been the abode of civilized beings4 ,thus it was early recognized in ,italy4 ,fourth3 ,it occurs in deposits of such a character that it can be readily obtained in a comparatively pure form from them4 ,fifth3 ,it possesses certain remarkable properties some of which would be easily detected even by savage peoples1 while others have for centuries excited great interest in the minds of students of alchemy and chemistry4 ,one of these properties is the ease with which it assumes a liquid form--that is1 melts--when slightly heated4 ,another is the readiness with which it takes fire and burns in the air4 ,a third1 closely connected with the foregoing1 is the striking blue flame produced when it burns4 ,still another1 and not less noticeable1 is the choking and disagreeable odor attendant upon this combustion4 ,finally may be mentioned a circumstance which for a long time contributed to make it peculiarly interesting to the alchemist1 if not to ordinary men3 this is the fact that when sulphur is in the pure form it may be burned away without leaving any ashes4 ,in this respect it differs from most other combustible materials4 ,and this property created the impression that sulphur is a sort of principle of fire1 and that it somehow exists in all combustible bodies4 ,indeed it is only for about a hundred years that sulphur has been classified as a distinct elementary form of matter4 ,it is not intended to indicate here that the strong interest of the alchemists in sulphur was mainly referable to the circumstances of its combustibility4 ,its power of combination with the metals was well known to them1 and was recognized as a subject of practical importance and one worthy of careful study and thought4 ,natural ,sources of ,sulphur4 ,the principal supply of sulphur for commerce is obtained from the volcanic districts of the island of ,sicily4 ,here in fact there are more than two hundred distinct establishments for production of the substance1 and they are capable of yielding about two hundred million pounds of it per year4 ,the fact that sulphur is easily and widely recognized in the earth has already been dwelt upon4 ,but it occurs in nature in a great variety of forms4 ,the first and most striking form is that of free and uncombined sulphur4 ,in this condition it occurs either as masses or as fine powder4 ,sometimes these materials possess the well-known and easily recognized yellow color of sulphur2 sometimes however the color is white or otherwise disguised by reason of some peculiarity of the sulphur itself or else because of the admixture of foreign substances4 ,deposits of sulphur occur in the most considerable quantities in the neighborhood of either active or extinct volcanoes4 ,thus sulphur earth occurs near ,vesuvius and tna1 also in the vicinity of the volcanoes of ,iceland1 in ,central ,america and in the ,sandwich ,islands4 ,in the region of some extinct volcanoes the soil is impregnated with sulphur to the depth of twenty or thirty feet and such soil is therefore a convenient source of the element4 ,purification of ,natural ,sulphur ,ores4 ,in obtaining sulphur from the earth for commercial purposes1 two simple processes are resorted to4 ,by the first method masses of the sulphur earth are heaped up into a pile1 in connection with a small amount of fuel and over a shallow depression in the earth4 ,upon setting the mass on fire1 considerable quantities of sulphur escape combustion1 and so melt and run down to the ground below the heap4 ,when the fire is extinguished1 the sulphur that collected beneath may be secured in a form now only slightly impure4 ,illustration3 ,,fig4 #dd4 ,calcarone or heap of burning mineral from which sulphur is obtained4 ,illustration3 ,,fig4 #de4--,sketch illustrating the process of refining sulphur4 ,the second method of purification of the earth is still conducted in ,sicily in the following crude manner1 though this is quite an improvement upon that just described4 ,a slightly inclined plane of masonry is built upon the ground4 ,around the edges of this plane a low wall is erected4 ,at the lower side of the plane the wall is perforated4 ,upon the surface of the plane large masses of sulphur earth are carefully piled up so as to form a well-built heap4 ,when it reaches the proper height its outside is covered all over1 first1 with small fragments of the same kind of earth1 and then with its fine dust4 ,some sulphur at the lower portion of the heap is then set on fire at several points4 ,the heat from the sulphur that burns melts other portions of it1 which then trickle down the spaces between the masses of rock4 ,this melted material1 finding the bottom of the pile1 runs freely to the lowest portion of the platform1 then through the perforations and out into wooden boxes placed to receive it4 ,the heap burns for two or three weeks1 at the end of which time the operation is finished4 ,when the mass is cool it is torn down1 and a similar pile is erected from fresh portions of the sulphur earth4 ,the objectionable features of this process are at least four4 ,first1 the consumption of sulphur as fuel is a wasteful one4 ,but in reply it may be said that no cheaper fuel is accessible where this manufacture is carried on4 ,again1 the great volumes of sulphur dioxide given out by the burning calcaroni--as the heaps are called--are injurious to the health of the workmen4 ,further1 these same products exercise a very destructive effect upon all vegetation in their vicinity4 ,in fact on this account the ,italian government has provided by law that this work shall not be carried on at all between ,july #ast and ,december #cast4 ,finally the method is not as successful with the richer ores1 for they break down into powder which it is difficult to utilize in the calcaroni4 ,a new and greatly improved method1 and one which overcomes all the objections above cited has recently been introduced4 ,in this1 the ore is placed in perforated metal baskets and then immersed in tanks containing hot solutions of calcic chloride4 ,under these conditions the sulphur melts out from its ore and falls to the bottom of the tanks1 whence it is drawn out by stop-cocks in a comparatively pure form4 ,sulphur is generally subjected to a still further purification4 ,this is conducted somewhat as follows4 ,the crude sulphur1 being melted in a suitable retort and over a coal fire1 changes into vapor and passes into an apartment constructed of stone or brick1 and prepared for the purpose4 ,in this apartment1 the sulphur at first condenses on the walls as minute yellow crystals or powder called flowers of sulphur4 ,when the first charge of sulphur in the retort has been completely vaporized a new supply is allowed to run in1 this time in the liquid form from a small heater placed above the retort4 ,the waste heat from the furnace melts the sulphur in the heater1 from which it flows into the retort 7by means of the tube shown in the diagram74 ,when a sufficient amount of flowers of sulphur has collected in the chamber1 the fire is extinguished4 ,the purer product is then removed4 ,afterward the whole operation is repeated4 ,the refining may be conducted so that the temperature of the condensing apartment may rise considerably2 in this case the vapor in it changes to the liquid form4 ,this liquid may be drawn off at the base of the chamber into a small receiver1 from which it is ladled into moulds1 which give it the form of cylinders known in trade as roll brimstone4 ,natural ,compounds of ,sulphur4 ,sulphur is also found in the earth in the form of certain chemical compounds4 ,some of these are very widely distributed4 ,they may be divided into two classes4 ,the first class--whose representatives are by far the more abundant--includes the metallic sulphides1 that is1 compounds formed by the direct union of sulphur with some metallic substance4 ,as examples of compounds of this class we mention3 ,sulphide of iron 7commonly called iron pyrites and having the formula ,fe,s74 ,sulphide of lead 7commonly called galena1 and having the formula ,pb,s74 ,sulphide of zinc 7commonly called blende1 and having the formula ,zn,s74 ,sulphide of mercury 7commonly called cinnabar and having the formula ,hg,s74 ,many other examples of similar import might be given1 for it is a well-known fact that most of the heavy metals occur in the earth in combination with sulphur4 ,the other class of compounds also containing sulphur combined with the metals has usually oxygen in addition4 ,two examples of this class may be given here--calcic sulphate 7commonly called anhydrite1 and having the formula ,ca,s,o72 also baric sulphate 7commonly called heavy spar1 and having the formula ,ba,s,o74 ,sulphur is very widely distributed in animal and vegetable matters4 ,in these it exists1 not as an uncombined element1 but in union with others4 ,indeed such compounds have many other elements besides the sulphur1 and they are characterized by decided complexity of structure4 ,but sulphur is oftener a component of animal matters than of vegetable4 ,the presence of sulphur in an egg is proved by an experiment of every-day occurrence4 ,that is to say1 the silver spoon with which the egg is eaten becomes blackened4 ,this blackening is due to the production of a new compound formed by a true union of sulphur from the egg1 with a part of the metal of the spoon4 ,in fact the black material is sulphide of silver1 and it may be represented by the formula ,ag,s4 ,a ,french chemist has estimated that in the body of a human being of ordinary size there exists1 in the aggregate1 not far from one quarter of a pound of sulphur4 ,to this1 he adds the curious estimate that the entire human population of ,france may be represented as containing not far from nine millions of pounds of sulphur4 ,chemical ,properties of ,sulphur4 ,the chemical properties of sulphur may be said to be its most important and interesting ones4 ,that it has a wide range of chemical aptitudes is shown by the fact that it combines in simple forms of union with a majority of the elements known4 ,thus it has strong affinities for most of the metals4 ,on the other hand it combines with various degrees of attractive force with nearly all the non-metals as well4 ,evidently then1 sulphur forms a very large number of chemical compounds4 ,while the limits of this work are such as to make it impossible to describe many of them1 there are three that may with propriety be briefly discussed in this place1 and these are3 ,sulphuretted hydrogen 7,h,s71 ,sulphur dioxide 7,,so71 ,sulphur trioxide 7,,so74 ,sulphuretted ,hydrogen4 ,this substance is a colorless gas4 ,it has an extremely offensive odor2 in fact it is a prominent component of that numerous group of gaseous products of decomposition of animal matters that produce the disagreeable smell attendant upon the decay of the latter4 ,again1 it is found in the waters of certain natural sulphur springs1 and it is a remedial agent of considerable value when properly applied externally or when taken into the stomach4 ,when received into the lungs1 however1 it is decidedly poisonous4 ,a considerable number of simple experiments may be tried with it4 ,in these the gas used is generated by adding diluted sulphuric acid to artificial ferrous sulphide4 ,the ferrous sulphide is usually manufactured by heating a mixture of roll brimstone and iron filings in a sand crucible4 ,in producing the gas1 the chemical change is represented by the following equation3 ,fe,s ,h,,so ,one molecule of ,one molecule of ,ferrous sulphide1 ,sulphuric acid1 #hh #ih parts by weight4 parts by weight4 _/ #ahf ,h,s ,fe,s,o ,one molecule of ,one molecule of ,sulphuretted hydrogen1 ,ferrous sulphate1 #cd #aeb parts by weight4 parts by weight4 _/ #ahf ,for the purpose of the experiments here mentioned1 a flask or bottle may be used to prepare the gas and convey it into another bottle containing water4 ,in the water1 the sulphuretted hydrogen gas dissolves in such quantity that the solution so afforded may be conveniently employed for showing the properties of the gas itself4 ,the following interesting experiments may be performed by use of this solution3 #a4 ,dissolve in water a small quantity of plumbic acetate1 also called sugar of lead4 ,filter this solution if convenient4 ,to the clear liquid1 add some sulphuretted hydrogen water4 ,a black precipitate of plumbic sulphide 7,pb,s7 should immediately appear4 #b4 ,dissolve in chlorohydric acid a fragment of white-arsenic not bigger than a pin's head4 ,to the solution1 freely add sulphuretted hydrogen water4 ,a beautiful lemon-yellow precipitate1 consisting of arsenious sulphide 7,as,s71 should result4 #c4 ,dissolve in chlorohydric acid a minute quantity of tartar-emetic4 ,to the solution1 freely add sulphuretted hydrogen water4 ,a beautiful orange red and flaky precipitate of antimonious sulphide 7,sb,s7 should appear4 #d4 ,dissolve in water a minute fragment of cupric sulphate1 commonly called sulphate of copper or blue vitriol4 ,to the solution1 add some of the sulphuretted hydrogen water4 ,this should instantly give rise to a black precipitate of cupric sulphide 7,cu,s74 #e4 ,dissolve in water a small quantity of zinc sulphate4 ,to the solution1 freely add sulphuretted hydrogen water4 ,there should appear in this case a white precipitate consisting of zinc sulphide 7,zn,s74 ,these few experiments show that sulphuretted hydrogen is a convenient substance for bringing sulphur into union with the metals1 and1 moreover1 they sustain the statements already presented1 that many metals show strong affinity for sulphur and marked tendencies to combine with it4 ,for these reasons sulphuretted hydrogen is much used in chemical laboratories for distinguishing one metal from another4#h #h ,see ,appleton's ,qualitative ,analysis1 published by ,cowperthwait ,co41 ,philadelphia2 p4 #ad4 ,sulphur ,dioxide4 ,when sulphur burns in oxygen gas or in atmospheric air1 it gives rise to a new gas of choking and offensive odor4 ,this is the same substance as that produced in the first stages of the burning of a sulphur match4 ,it is a substance of considerable importance in the arts1 first1 because it is always produced in one stage of the process used in the manufacture of sulphuric acid4 ,now sulphuric acid 7commonly called oil of vitriol7 is a commercial product of enormous consumption4 7,see page #aeb47 ,again1 sulphur dioxide is used1 as such1 to a considerable extent in the arts1 the principal uses being in the bleaching of straw and woolen goods4 ,chlorine as a bleaching agent has already been discussed1 but it is used mainly for the bleaching of cotton and linen goods2 it has an unfavorable and injurious action upon straw and woolen goods4 ,the way in which these latter are bleached by the use of sulphur may be illustrated by a very simple experiment4 ,place a few fragments of roll brimstone in a small crucible4 ,heat the crucible carefully until the sulphur takes fire4 ,then cover the burning sulphur with a glass lamp-chimney1 or any other suitable contrivance4 ,in the top of the chimney hang a moistened carnation pink or other red flower4 ,a few minutes exposure to the gas1 results in a partial bleaching of the flower4 ,on a commercial scale1 the sulphur bleaching process is conducted in practically the same manner4 ,for bleaching woolen goods there is provided a small wooden house having a brick floor1 with a small pit in the centre4 ,the goods are hung up in this house4 ,the pit is filled with sulphur which1 when all is ready1 is set on fire by throwing a piece of red-hot iron upon it4 ,now the doors and windows of the house are closed4 ,of course the sulphur burns into sulphur dioxide4 ,the operation is allowed to proceed without any further attention during one night4 ,the gas distributes itself throughout the goods and bleaches them4 ,the next morning the doors and windows are opened1 and1 when the fresh air has driven the sulphur dioxide from the chamber1 the goods are found bleached4 ,everyone knows1 however1 that this bleaching has not the permanence that chlorine bleaching has4 ,thus white flannels very soon return to their original yellowish shade4 ,sulphur dioxide is placed by the chemist in the class of acid anhydrides4 ,this term is intended to carry the meaning that substances belonging to this class combine with water to form acids4 ,in accordance with this form of expression1 sulphur dioxide is also called sulphurous anhydride4 ,plainly this means that sulphur dioxide with water will form an acid4 ,such seems to be indeed the case1 for water has the power of dissolving large quantities of sulphur dioxide1 and when it does so the water acquires the characteristics of an acid4 ,in fact it is then called sulphurous acid4 ,the chemical change is represented by the following equation3 ,,so ,h,o ,h,,so ,one molecule of ,one molecule of ,one molecule of ,sulphur dioxide1 ,water1 ,sulphurous acid1 #fd #ah #hb parts by weight4 parts by weight4 parts by weight4 _/ _/ #hb #hb ,one special characteristic which justifies the name sulphurous acid1 is the fact that the solution so produced has the power of producing a series of salts as the other acids do4 ,in this case1 the salts have the general name sulphites4 ,,chapter ,,xvii4 ,,sulphur ,,trioxide4 ,sulphur trioxide does not exist by itself in nature4 ,moreover it is but little known even as an artificial product4 ,it is not an article of ordinary sale1 though it is occasionally made by the chemist4 ,yet it is a constituent part of one of the most important compounds known to modern industry4 ,that compound is sulphuric acid4 ,sulphur trioxide is a white solid1 but it cannot easily be kept so4 ,this is because it has very strong affinity for moisture4 ,it fact it readily absorbs that water-vapor which is distributed through the atmosphere1 even in dry weather and when the ordinary observer would suppose that the air contained no moisture at all4 ,when it absorbs moisture it chemically combines with it1 forming sulphuric acid4 ,the chemical change is represented by the following equation3 ,,so ,h,o ,h,,so ,one molecule of ,one molecule of ,one molecule of ,sulphur trioxide1 ,water1 ,sulphuric acid1 #hj #ah #ih parts by weight4 parts by weight4 parts by weight4 _/ _/ #ih #ih ,on account of this reaction1 sulphur trioxide is often spoken of as sulphuric anhydride1 the term anhydride being intended to suggest that the substance so named is derived from an acid by the removal of water from the latter4 ,thus sulphuric acid minus water produces sulphuric anhydride4 ,and this harmonizes with what has before been declared1 namely1 that sulphuric anhydride--or sulphur trioxide--plus water produces sulphuric acid4 ,sulphuric ,acid4 ,this substance is known to commerce chiefly under the name of oil of vitriol4 ,it is an oily liquid nearly twice as heavy as water4 ,it has very powerful chemical action upon most substances with which it comes in contact4 ,moreover1 its market price is very low1 that is1 between one and two cents a pound at wholesale4 ,to these two facts last mentioned--that is1 the marked chemical power and the low price is referable the enormous demand for the substance4 ,to be sure1 increase of demand and fall in price have a reciprocal action2 for even a slight cheapening of a substance widens considerably the range of its possible uses and increases the amount consumed4 ,again1 increase of demand and consumption1 lead manufacturers to increase their production1 a circumstance which is generally followed by lower price4 ,the manufacture of sulphuric acid exemplifies these well-known principles of political economy4 ,the manufacture of this substance has risen within the last hundred years from almost nothing to a present annual production of about nine hundred thousand tons in ,great ,britain alone4 ,the price meanwhile has fallen to about one-thirtieth of what it was in the middle of the last century4 ,at the present time the price of oil of vitriol seems to be steadily decreasing1 while the amount produced is steadily increasing in ,england1 ,france1 ,germany and the ,united ,states--indeed in all countries pervaded by active industrial enterprises4 ,it will be generally admitted1 as ,m4 ,dumas has said1 that the amount of sulphuric acid consumed affords a very precise measure of the advancement in industrial arts of a given country or of a historical epoch4 ,illustration3 ,,fig4 #dh4--,section of chambers for manufacture of sulphuric acid4 ,uses of ,oil of ,vitriol4 ,it would be difficult to enumerate the many industries that demand the use of sulphuric acid4 ,it must likewise be admitted that there are but few manufacturing operations which do not directly or indirectly involve its employment4 ,the industries that stand in the front rank as direct consumers of this acid are those that involve the following processes1 namely3 the bleaching of cotton goods2 the removal of scale from iron in its various forms1 such as castings1 wire1 etc42 the changing of corn starch into the variety of sugar commonly called glucose2 the refining of bullion of gold and silver2 the refining of petroleum oil2 last1 but not least1 the manufacture of chemical fertilizers for agricultural use4 ,less directly1 but still in enormous quantities1 it is used in the manufacture of soda-ash1 and bleaching powder already referred to as having reached an incredible consumption2 in the manufacture of alum2 in the manufacture of both of the great acids of commerce1 chlorohydric acid and nitric acid1 which must be said to come next to sulphuric acid in usefulness2 and finally1 in almost all the distinctly chemical industries4 ,manufacture of ,sulphuric ,acid4 ,notwithstanding the extremely low price of oil of vitriol and the immense quantity of it manufactured1 its production implies a series of processes far more complicated than those involved in the preparation of any other well-known acid4 ,moreover1 although the various intricate details of its preparation are matters of thorough experimental knowledge to the producer1 there are several steps which are not yet clearly comprehended even by the most eminent chemists of the age4 ,the process of manufacture1 as at present conducted1 is properly described as a continuous one4 ,by this it is meant that the raw materials are steadily introduced at one end of the apparatus used1 and the finished product is steadily drawn out at the other1 the process meanwhile going on without interruption1 night and day1 for years4 ,in order to a better comprehension of the process it is here described in four stages4 ,in the first stage1 sulphur is burned in a current of air4 ,the material employed is either partly refined ,sicily sulphur1 or what is largely used at the present day1 some mineral compound of sulphur1 like the iron and copper pyrites4 ,in either case1 sulphur dioxide 7,,so7 is formed4 ,this is the well-known choking gas given out by a burning sulphur match4 ,as produced on a large scale the gas passes into a series of enormous leaden chambers4 ,these are1 in fact1 rectangular rooms1 often as large as one hundred and fifty feet long1 twenty feet wide and fifteen feet high4 ,generally at least three chambers are in a series1 connected by leaden pipes4 ,sulphur dioxide gas flows in a steady stream into the series of chambers and toward the high chimney of the works1 whose draft produces the advance of gases through the whole apparatus4 ,illustration3 ,,fig4 #df4--,section of building fitted for manufacture of ,sulphuric acid2 f1 furnace where sulphur is burned and oxides of nitrogen are liberated2 k1 boiler from which steam is supplied to the leaden chamber1 ,a4 ,the second stage is the most complicated one4 ,it is the oxidizing of the sulphur dioxide 7,,so7 into sulphur trioxide 7,,so74 ,this is indeed accomplished by means of the oxygen of the air4 ,but this oxygen is not capable of directly changing ,,so into ,,so4 ,certain gaseous oxides of nitrogen are forced into the chamber at this stage2 and these have the remarkable power on the one hand of taking oxygen to themselves from the air1 and on the other of imparting this oxygen to the compound ,,so in such a way as to change it into the compound ,,so4 ,of course the air is impoverished by the operation1 a fact which necessitates a fresh supply of it through the entire series of chambers4 ,the third stage is one whose principle has already been explained4 ,at various parts of the chamber1 jets of steam are blown in4 ,while these aid mechanically in the progress of the gases through the entire series1 their main purpose is to furnish water which shall combine with sulphuric anhydride to produce sulphuric acid4 ,although this chemical change1 represented by the following equation1 has been given before1 it may not be improper to repeat it here3 ,,so ,h,o ,h,,so ,one molecule of ,one molecule of ,one molecule of ,sulphur trioxide1 ,water1 ,sulphuric acid4 #hj #ah #ih parts by weight4 parts by weight4 parts by weight4 _/ _/ #ih #ih ,the effect of the steam is to give rise to a steady rain of oil of vitriol in the chambers4 ,of course this liquid collects at the bottom4 ,thence it is drawn off1 for treatment in a fourth stage4 ,it is plain that up to this point the series of chemical reactions takes place in what we may characterize as a vast but irregular tube1 open at both ends4 ,this tube is enlarged here and there into great pockets which constitute the chambers4 ,it is bent into a form appropriate to the conditions of the business4 ,it is entered here and there by pipes for introducing the agents whose proper interaction gives rise to the product sought4 ,it is also tapped for the purpose of drawing off the acid generated4 ,this open tube has its final exit into the atmosphere through the tall chimney with which it is connected4 ,it has its first connection with the atmosphere at the open throat1 which swallows at once the vast volumes of sulphurous gas from the sulphur burned1 and at the same time levies upon the air to contribute its oxygen to produce the substance which is the final purpose of the whole industry4 ,the fourth stage is the only one that may be properly said to be disconnected from the others4 ,the continuous process already described cannot properly be made to produce acid of the strength demanded by commerce4 ,in the fourth stage then1 the acid from the chambers is boiled with a view of expelling some of the water in it1 and thus of producing a more concentrated product4 ,this evaporation is itself no inconsiderable portion of the business4 ,it is conducted first in shallow tanks of lead1 and finally in costly stills of platinum4 ,when at length the acid in the platinum stills has attained the proper degree of concentration1 it is drawn out by means of a siphon tube1 and through a cooling tank of cold water1 into the glass flasks called carboys1 in which it makes its appearance in commerce4 ,illustration3 ,,fig4 #dg4--,section of apparatus used for concentrating sulphuric acid4 ,a1 ,a1 leaden pans in which the first evaporation is conducted2 ,b1 platinum retort in which the concentrating is finished4 ,of course the account thus given is but a general sketch of this great industry4 ,associated with the apparatus and the processes here briefly described there are employed in actual working a multitude of other devices and operations4 ,indeed it might be anticipated that the successful conduct of a business of such magnitude and complexity would draw upon the inventive resources of some of the best minds that have been brought to bear upon chemical industries4 ,,reading ,,references4 ,sulphur ,industry in ,sicily4 ,barbaglia1 ,a4--,chem4 ,news4 xxxiv1 #bde2 xxxv1 #c1 #bh4 ,vincent1 ,c4--,am4 ,chem4 ,journal4 vi1 #fc4 ,sulphur1 ,extraction of4 ,sestini1 ,f4--,jour4 of ,chem4 ,soc4 of ,london4 xxviii1 #cce4 ,sulphuric ,acid4 ,affleck1 ,j4--,chem4 ,news4 xxxvii1 #afg1 #aib1 #bjg4 ,hasenclever1 ,r4--,chem4 ,news4 xxxv1 #dh1 #fg1 #hh1 #aah1 #ahc1 #ahi1 #bad1 #bbg4 ,,chapter ,,xviii4 ,,boron4 ,the white substance called borax has long been known to exist as a solid deposit in the earth of many parts of the ancient ,east4 ,but its uses have increased a thousand fold as the result of the modern discovery of new and far more abundant sources of it4 ,thus in the manufacture of porcelain and in other of the industrial arts1 and as a remedial agency in medicine1 borax has now come to be an important and truly useful substance to mankind4 ,the knowledge of its composition is referable to a very recent date2 only in the present century its character as a true chemical salt was fully made out4 ,borax is now recognized as sodic borate1 which usually exists in a form holding ten molecules of water of crystallization2 accordingly the chemical formula is ,na,b,o #aj ,h,o4 ,from this it appears that1 in addition to the well-known substances sodium and oxygen1 borax contains a special and peculiar element called boron--a name evidently derived from borax4 ,again1 being a salt1 the substance must be viewed as containing an acid--or more properly speaking1 the representative of an acid4 ,that this is indeed the fact may be readily proved4 ,if borax is dissolved in water in such a way as to form a concentrated solution1 then1 upon addition of chlorohydric acid1 a solid substance separates out in pearly flakes2 this upon subsequent examination is found to be an acid4 ,this solid acid has received the name boric acid1 and it may be represented by the formula ,h,,bo4 ,illustration3 ,,fig4 #di4--,view among the ,tuscan lagoni before the introduction of the borax industry4 ,illustration3 ,,fig4 #ej4--,view in ,tuscany after the establishment of the borax industry4 ,sources of ,borax in ,nature4 ,for a long time the only known source of borax was the natural crusts of this substance found principally in the ground in certain parts of ,asia4 ,at the present day1 however1 borax is obtained from ,borax ,lake1 in ,california1 in very large quantities4 ,in fact the commercial needs of the ,united ,states for this substance1 are readily supplied from borax found within its own borders4 ,the most interesting and important step in connection with the preparation of borax dates back to about the year #aggf1 when the fact was made public that certain lagoons in ,tuscany contained boric acid in their water4 ,it was not until about the year #ahbh1 however1 that the manufacture of boric acid from this source was successful upon a large scale4 ,in some of the ,tuscan valleys there are volcanic crevices in the earth1 called suffioni4 ,from them steam escapes charged with certain compounds of boron4 ,when this steam is brought in contact with water1 boric acid is liberated in the water4 ,the method of securing the acid is as follows3 ,a ring of masonry is built in a suitable place and so as to include several suffioni4 ,sometimes new suffioni are artificially bored within this ring4 ,into the basin so produced1 water from some convenient spring is conducted4 ,the steam from the suffioni passing into the water1 produces boric acid there4 ,when the water is sufficiently charged1 it is made to flow as a gentle cascade over a long series of shallow pans4 ,the liquid readily evaporates from these pans for under them also1 steam from suffioni is turned4 ,it is indeed this last mentioned step in the manufacture1 that became the turning point which has lead to its successful prosecution4 ,the great cost of fuel for artificially evaporating the acid liquors1 rendered unprofitable the earlier attempts to utilize this source of boric acid4 ,a ,french gentleman1 ,m4 ,larderel1 suggested the use of steam from suffioni for the evaporation of the liquids produced1 and the process was so successful that he quickly derived a colossal fortune from its employment4 ,at the same time he enriched the territory that was previously not only desert and unproductive1 but also was looked upon by the inhabitants with superstitious dread and as little better than the gate of the infernal regions4 ,as a result of these inventions1 a barren and unfrequented territory has been changed to a seat of thriving and beneficial industry4 ,finally1 it is interesting to note that for his services in developing the boric acid industry ,m4 ,larderel was created ,count of ,monte-,cerboli by the ,grand ,duke of ,tuscany4 ,,reading ,,references4 ,boric ,acid1 ,manufacture of1 etc4 ,payen4--,annales de ,chimie et de ,physique4 #c ,sr4 i1 #bdg2 ii1 #cbb4 ,dieulafait1 ,l4--loc4 cit4 #e ,sr4 xii1 #cah2 xxv1 #ade4 ,borax ,lagoons of ,tuscany4 ,harper's ,magazine4 i1 #cig4 ,,chapter ,,xix4 ,,nitrogen4 ,nitrogen is an important constituent of our atmospheric air of which it makes up about eighty per cent4 ,the other twenty per cent41 as has already been stated1 is oxygen4 ,in the air the nitrogen is found in the free or uncombined state1 and we may reasonably suppose that it exists here to fulfil some important offices4 ,unquestionably one of these is that of diluting the oxygen1 the energetic constituent of air1 and lessening its activities--for nitrogen itself is extremely inert4 ,from the part it performs in the atmosphere1 nitrogen derives a considerable portion of the interest with which it is invested4 ,discovery of ,nitrogen4 ,perhaps the first clearly defined recognition of nitrogen as a constituent of the air is referable to the genius of a wonderful man1 who1 in obscurity and with the most imperfect appliances1 obtained an insight into the constitution of substances which has rarely been surpassed4 ,reference is here made to the ,swedish1 or rather ,prussian1 chemist ,scheele1 some of whose discoveries have been briefly adverted to in earlier chapters4 ,it has already been stated that the distinct notion of a gas dates but little more than a hundred years back2 and this statement is intended to call to mind that brilliant period in the history of chemistry when among others1 ,black in ,scotland1 ,cavendish and ,priestley in ,england1 ,lavoisier and his worthy associates in ,france1 and finally1 the sagacious ,scheele in ,sweden1 were engaged in a generous rivalry in chemical studies1 which made the close of the eighteenth century a period in the history of chemistry that will not be forgotten so long as the science itself shall endure4 ,at this time unstinted effort was devoted1 with ingenious but imperfect appliances1 to the study of gases4 ,of course the atmospheric air1 as the gas most vast in quantity1 most accessible for experiment1 most important in its relation to the economy of living nature1 received its full share of attention4 ,it was at this period that ,dr4 ,rutherford1 a professor in the ,university of ,edinburgh1 demonstrated that after living animals have breathed in a confined bulk or volume of air1 there remains an inert and peculiar gas behind4 ,and ,priestley showed that after the burning of charcoal in a confined volume of air there remains a gaseous material equal to about four-fifths of the amount of original air used4 ,but it was ,scheele who first clearly pointed out that the air contained a second distinct constituent that fails to support combustion and animal respiration4 ,and ,lavoisier first proved this constituent to be an elementary substance and he gave to it the name azote1 which it still retains in the ,french nomenclature of chemistry4 ,it is not forgotten that a critical examination of the history of human knowledge respecting the atmosphere reveals the fact that a wonderfully clear1 even though incomplete1 account of the functions of the active constituent of the air was printed as early as the year #affi1 by an ,english physician named ,john ,mayow4#i ,this affords another illustration of the fact1 recognized by all students of history1 that often in the progress of knowledge1 before the clear and full dawn there seems to be a twilight2 at such a time1 and before the darkness has been fully dispelled1 there have been found here and there men gifted with supernatural vision who have been able to read the laws of nature long before acknowledged philosophers even had found light sufficient4 ,and so the truths learned by ,mayow1 though clearly stated by him1 failed of recognition until they were rediscovered a hundred years later4 7,see p4 #aba47 #i ,,kopp1 ,,hermann3 ,geschichte der ,chemie4 ,dritter ,theil4 s4 #aic4 ,preparation of ,nitrogen4 ,nitrogen is usually prepared from the air by the withdrawal of oxygen from it4 ,this withdrawal is effected by some substance which has a strong affinity for oxygen4 ,thus one method frequently resorted to for the preparation of nitrogen1 is to burn phosphorus in air4 ,phosphorus is placed in a little crucible of porcelain and then floated upon a cork on the surface of water in a pneumatic trough4 ,a bell-glass of air is now inverted over the phosphorus1 after the latter has been set on fire4 ,the phosphorus burns at the expense of the oxygen in the bell-glass4 ,thus the oxygen is little by little withdrawn and as a result the nitrogen is left4 ,illustration3 ,,fig4 #ea4--,preparation of nitrogen from air1 by absorbing the oxygen by burning phosphorus4 ,another method for preparing nitrogen is based upon the same general principle4 ,it is the following3 ,pass a current of dry air through a tube containing copper turnings heated to dull redness in a furnace4 ,under these circumstances the copper absorbs oxygen from the air1 and leaves the nitrogen1 which passes on to a receiver prepared for it4 ,properties of ,nitrogen4 ,nitrogen prepared by these methods1 or by any others1 possesses the following characteristics3 ,it is a gas that is colorless1 odorless and tasteless4 ,it is not necessary to make any scientific demonstration of these facts1 because with every breath of air drawn into the lungs of a human being a large quantity of nitrogen is inhaled1 and it is easily perceived to be without odor or taste1 while a glance of the eye into the atmosphere shows that1 in moderate quantities at least1 it is free from color4 ,up to a period dating but a few years back1 nitrogen was spoken of as one of the permanent gases2 and this word permanent was intended to convey the idea that it is not condensable to the liquid form4 ,it is true that it was surmised that for every gas there must be a point of very low temperature and very great pressure at which the gas would assume the liquid form4 ,yet nitrogen1 and two or three others1 successfully resisted all such attempts to liquefy them until toward the close of the year #ahgh4 ,since that time1 successful effort has been made to bring to a higher degree of perfection the appliances used for subjecting gases at once to intense cold and enormous pressure4 ,with these1 it is believed that small amounts of nitrogen have been liquefied4 ,and it may even be said that there is now no permanent gas known1 but that all gaseous substances may in fact be liquefied4#aj #aj ,,scrutzenberger1 ,,paul3 ,trait de ,chimie ,gnrale1 ,paris1 #ahhj1 i1 #cj4 ,as a simple and uncombined substance1 nitrogen is characterized by extreme inactivity4 ,it does not burn2 it does not support combustion2 it cannot be made to enter into chemical union with other substances1 except by specially devised and circuitous processes4 ,while on the one hand inertness is the marked characteristic of the nitrogen1 on the other hand this element is a constituent of a very large number of compounds4 ,moreover1 these compounds are themselves often characterized by a high degree of activity4 ,of the last two declarations the first one seems to be inconsistent with the properties of nitrogen in its elemental form4 ,the second one seems inconsistent1 but less so when it is carefully considered4 ,thus the activity of the compounds of nitrogen is to a certain extent referable to their instability4 ,the meaning of instability1 as used here1 is that the compounds are easily decomposed2 and this is because the inert nitrogen readily lets go its hold upon the other elements4 ,whence it appears1 that the activity of the compounds1 in reality referable to the energetic action of the element or elements now loosed from the nitrogen1 rather than the nitrogen itself4 ,in nature1 nitrogen is found as a constituent in some very important compounds4 ,thus it seems to be an essential element of some of the principal animal matters1 such as muscular fibre and the material of the brain4 ,again1 it is a constituent of ammonia gas and also of a multitude of compounds derived from it4 ,now these compounds are members of a group of substances which serve as most valuable kinds of food for living plants4 ,so it may be said that both living animals and plants seem to be in a peculiar way dependent upon nitrogen or nitrogenous matters4 ,compound of ,nitrogen with ,hydrogen4 ,under favorable circumstances1 nitrogen and hydrogen combine to form the stable1 interesting and important compound called ammonia gas and having the formula ,,nh4 ,while this gas may be produced by the direct union of the constituents--that is when a mixture of nitrogen gas with hydrogen gas has an electric discharge slowly passed through it--this is not a common mode of procedure4 ,ammonia gas is oftener produced by a natural or artificial decomposition of certain substances that contain nitrogen and hydrogen among their constituents4 ,as it has already been stated that many animal matters contain nitrogen and hydrogen1 it follows that animal matters when decomposed1 afford ammonia gas2 and so they do1 in fact1 whether the decomposition is in the course of their natural decay1 or whether it is conducted artificially1 as for example when animal matters are heated in closed vessels to the point of decomposition4 ,indeed ammonia gas and its important commercial compounds were formerly produced in this last mentioned manner4 ,ammonia gas--or some compound of it--is also formed1 as may be readily imagined from what has already been said1 from decomposition of vegetable matters containing nitrogen4 ,it is a fact that at the present day the principal supplies of ammonia gas and its compounds for the uses of commerce and the arts come from such a source1 that is from the artificial decomposition of bituminous coal4 ,it is true that in the ordinary sense coal is not vegetable matter4 ,but careful examination of it1 shows that it is very directly derived from the vegetation of ancient forests4 ,the vegetable matter has been packed away in the earth and has been subjected to water1 heat and pressure under such conditions that these agencies have changed it to the form in which we find it4 ,now the coal-gas industry of the present day is so conducted as to decompose coal and collect many of the products of its decomposition4 ,one of these products is ammonia gas4 ,to the decomposition of coal1 therefore1 the business world at present looks for its supply of ammonia gas and the many compounds derived from it4 ,the name ammonia gas1 indicates that it ordinarily exists in the aeriform condition4 ,it has a very pungent odor1 well-known as that evolved from smelling-salts4 ,it dissolves in water with very great facility and in very large quantities4 ,it has a strong tendency to combine with acids4 ,this last fact may be easily illustrated by simple experiments within the reach of almost any one4 ,experiment with ,ammonia4 ,provide two wine-glasses or two shallow vessels of any sort4 ,into one of them pour the liquid known as spirits of hartshorn1 and called by the chemist ammonic hydrate4 ,into the other pour some concentrated chlorohydric acid4 ,abundant white clouds will quickly form above the vessels and between them4 ,these clouds are composed of minute particles of a solid1 called by the chemist ammonic chloride and expressed by the formula ,,nh,cl4 ,the reason for their formation is this3 from the spirits of hartshorn escapes ammonia gas 7,,nh72 from the acid there constantly escapes chlorohydric gas 7,h,cl72 the two gases meeting in the atmosphere combine with energy1 and form the smoky product referred to4 ,the chemical change is represented by the following equation3 ,,nh ,h,cl ,,nh,cl ,one molecule of ,one molecule of ,one molecule of ,ammonia gas1 ,chlorohydric acid1 ,ammonic chloride1 #ag #cf #ec parts by weight4 parts by weight4 parts by weight4 _/ _/ #ec #ec ,the ammonic chloride thus produced is an article of commerce1 well-known under the name sal ammoniac4 ,as has been said1 it is a solid and it belongs to the class of substances designated by chemists as salts4 ,in fact one of the most striking characteristics of ammonia gas is its power to produce salts by union with acids4 ,here is a list of three well-known salts of this sort3 ,with ,chlorohydric acid1 ,h,cl it produces ,ammonic chloride1 ,,nh,cl 0 ,nitric acid1 ,,hno it produces ,ammonic nitrate1 ,,nh,,no 0 ,sulphuric acid1 ,h,,so it produces ,ammonic sulphate1 7,,nh7,,so ,compounds of ,nitrogen and ,oxygen4 ,nitrogen and oxygen ordinarily manifest scarcely any affinity for each other4 ,there are conditions however under which they unite2 and moreover they unite in different proportions so as to form at least five different compounds4 ,these may be presented in the form of the following striking series3 ,nitrogen protoxide 7called laughing-gas17 ,n,o4 ,nitrogen dioxide1 ,n,o 7or ,,no74 ,nitrogen trioxide or nitrous anhydride1 ,n,o4 ,nitrogen tetroxide 7brown fumes17 ,n,o 7or ,,no74 ,nitrogen pentoxide or nitric anhydride1 ,n,o4 ,of these compounds1 unquestionably the most important is nitric anhydride--and this not on account of itself1 for it is very rarely produced either in the arts or in the investigator's laboratory4 ,its importance is referable to the fact that added to water1 it produces nitric acid4 ,this chemical change is represented by the following equation3 ,n,o ,h,o #b;,,hno ,one molecule of ,one molecule of ,two molecules of ,nitric anhydride1 ,water1 ,nitric acid1 #ajh #ah #abf parts by weight4 parts by weight4 parts by weight4 _/ _/ #abf #abf ,nitric ,acid4 ,this acid has been referred to in another place as one of three principal acids of commerce4 ,certain of its most striking properties may be displayed in an easy and interesting manner by any one4 ,for this purpose the following experiments are suggested3 ,first experiment4--,nitric acid turns quill yellow4 ,place a few fragments of white quill in a test-tube4 ,add a few drops of nitric acid and then some water4 ,now warm the mixture4 ,the quill will be found to acquire a yellow color4 ,fill the tube with cold water in order both to dilute the acid and to cool it4 ,pour away the liquid1 and wash the quill in water4 ,the yellow color will be found to be permanent4 ,many other animal matters are turned to a permanent yellow color by nitric acid4 ,second experiment4--,nitric acid attacks copper with violence4 ,there is liberated by the process a gas called nitrogen dioxide 7,n,o71 which is colorless but which becomes brown upon exposure to the atmospheric air4 ,the chemical change gives rise to a solution sometimes green and sometimes blue1 according to circumstances4 ,place in a test-tube a small piece of metallic copper in the form of either wire or foil4 ,add some nitric acid to the copper4 ,then warm it gently until the copper disappears4 ,the brown fumes will be recognized4 ,the colored solution of cupric nitrate1 ,cu7,,no7 should also be noticed4 ,third experiment4--,nitric acid attacks zinc with great violence4 ,try another experiment quite similar to that just described1 only employ zinc in place of copper4 ,brown fumes are evolved1 and a colorless solution is produced containing zinc nitrate1 ,zn7,,no74 ,fourth experiment4--,nitric acid attacks iron with violence4 ,try another experiment1 quite similar to the second and third1 only employ iron instead of the other metals mentioned4 ,the fine iron wire used by florists is suitable for this purpose4 ,the same brown fumes are evolved4 ,a metallic nitrate is also produced2 it is called ferric nitrate and its formula is ,fe7,,no74 ,the solution is yellow1 or but slightly colored4 ,fifth experiment4--,nitric acid dissolves a nickel coin4 ,an experiment similar to those already detailed may be tried upon a nickel coin2 but it is not necessary to entirely dissolve the coin4 ,after the acid has acted for a few moments1 water may be poured into the tube so as to dilute the acid1 and at the same time to cool it4 ,then the liquid may be poured away and the coin withdrawn4 ,in addition to the brown fumes evolved1 the feature most noticeable is the decided green color of the solution4 ,this is referable1 to a considerable degree at any rate1 to the nickel present4 ,nickel imparts a green color to most of its solutions4 ,these experiments suggest that nitric acid has a marked influence upon the metals4 ,this is in fact one of its prominent characteristics2 and it is largely used in the arts for the purpose of dissolving metals4 ,,chapter ,,xx4 ,,the ,,atmosphere4 ,the atmosphere or the air of our globe is the vast ocean of gaseous matter at the bottom of which human beings1 as well as other land animals1 dwell4 ,while it is so thin that a vessel full of it is spoken of in ordinary language as being empty1 it yet possesses a reality which it often displays in a very serious manner4 ,its presence is made gently evident to human beings by the moderate resistance it offers to them when they are in motion2 but when itself is in motion with the force of the hurricane or tornado1 no solid matters can stand in its path4 ,heavy railroad trains and massive buildings are hurled from their positions and turned into miserable masses of wreckage1 while even strongly rooted forests are swept out of place by its vigorous breath4 ,the terribly destructive power of air at one moment and its mild and subtle efficiency at another are very suggestive of the wonderful adjustment of the forces residing in it4 ,it is by the restrained action of these forces that the atmospheric air is so admirably fitted to perform its varied functions in connection with animal life4 ,at the same time it is so unobtrusive in its workings that its very existence is at first scarcely noted4 ,when at rest1 it peacefully wraps the earth about as in a gossamer veil1 but when in angry agitation it scourges country and city alike as with a whip of gigantic cables4 ,the height to which the atmospheric air extends above the earth is not exactly known4 ,but carefully devised experiments have shown that going upward1 its compactness or density diminishes very rapidly4 ,indeed calculations based upon exact experiment show that at a height of fprty miles1 or thereabouts1 from the surface of the earth1 the air is so highly rarified that practically it there comes to an end4 ,in other words1 at this height a given bulk of space contains no more air than exists in the so-called vacuum produced by a superior air-pump4 ,weight of ,air4 ,notwithstanding the extreme tenuity of the gaseous medium in which we live1 it is capable of buoying up on its wings a multitude of living beings of vast aggregate weight4 ,it is firm enough to support the millions of birds that sail in it1 and the myriad of millions of insects who yet more freely navigate it in search of food and warmth1 and in answer to the various needs of their existence4 ,one of the most striking evidences of the fact that air is indeed a material substance is very easily discovered by showing that it possesses weight4 ,thus suppose a properly constructed glass globe is almost entirely emptied of air by the action of an efficient air-pump4 ,suppose then that the globe is weighed4 ,next if it be connected with a bell-glass containing ordinary atmospheric air over a pneumatic trough1 it may be readily seen that the air leaves the bell-glass in order to pass into the globe4 ,if this globe is now weighed again1 it is found to manifest a decided increase of weight4 ,this increase is due to the air it has received4 ,by such means it may be easily shown that a cubic yard of air weighs not far from two pounds4 ,composition of ,air4 ,the principal constituents of air are the two gases oxygen and nitrogen2 and of these the oxygen makes up about one-fifth and the nitrogen about four-fifths of the whole4 ,in addition to these principal substances1 however1 certain others are always present1 of which may be specified vapor of water1 carbon dioxide and ammonia gas2 while more minute quantities of a vast multitude of other gaseous substances find a reservoir in the air4 ,it is an unquestioned fact that the atmosphere is likewise charged most of the time with still more minute quantities of solid dust materials of various kinds4 ,an example is found in the common salt1 blown up into the atmosphere from the ruffled surface of the oceans4 ,now the oceans are spread over fully three-fourths of the earth's surface1 and the winds1 blowing upon the crested waves1 not only diffuse the salt over the oceans themselves but also carry it far inland2 accordingly spectrum analysis reveals the presence of salt in almost all atmospheric air4 ,just as the rivers of water flow to the ocean and bear along to it debris of every kind--pulverized rock and earthy materials and other washings from the soil1 leaves of forests1 impure products of civilization thrown in from houses and manufacturing establishments--and all these materials make their relatively minute contributions to the impurities in the great ocean itself1 so it is with the atmospheric ocean4 ,thousands of millions of living animals pour out1 with every breath from the lungs1 materials exhaled from their bodies4 ,and so wherever fuel is burned1 or wherever manufacturing establishments liberate gases or vapors1 or even finely pulverized solids1 these are cast forth from the mouths of their reeking chimneys2 and they all flow into the great aerial sea4 ,so then it is no unexpected circumstance that the air should be a reservoir in which1 in minute quantity1 is likely to exist every gaseous substance produced4 ,offices of the ,several ,constituents of the ,air4 ,the oxygen of the air is its most active constituent4 ,this is the substance that has already been described as essential for all ordinary combustion and all animal respiration4 ,by a great variety of characteristics it is well fitted for these important offices4 ,the chief duty of the nitrogen appears to be to dilute the oxygen and moderate the excessive activities that would be manifested if the atmosphere consisted entirely of the active gas4 ,since iron and other metals burn in pure oxygen1 it is plain that in an atmosphere of oxygen--containing no moderating gas like nitrogen--a fire once kindled in a stove would not confine itself to its proper fuel1 but would soon spread to the metal of the stove itself1 and so initiate conflagrations that could hardly be restrained4 ,the moisture in the air adds a number of wonderful and serviceable characteristics to it4 ,thus it helps to retain the heat received from the sun and so materially contributes to the sustenance of animal and vegetable life4 ,the heat of the sun penetrates our atmospheric coverlet with great readiness and this heat is received by the surface of the earth and thence is imparted to the layer of air immediately upon it4 ,now the moisture contained in the atmosphere--and in principal quantity in the portions of air closest to the earth--is one of the chief agencies that prevent the immediate escape of that heat that the solid earth has secured from the sun's rays4 ,and it is in the warm layer of air so produced that animals and plants chiefly flourish4 ,ascend a mountain's side and a height is soon reached at which eternal snow and cold prevail1 where animal life cannot penetrate and even the lowest forms of vegetable life can hardly make their residence4 ,what has thus far been said points out a valuable office of watery vapor and one that is entirely in addition to that which this same material performs as it floats in the clouds1 ready to fall as beneficent showers and then to proceed to the other steps in the progress of that useful circulation which it performs as a liquid4 ,but it may not be out of place to mention here that the aqueous vapor in the atmosphere appears to serve in another way for man's pleasure1 even though in this particular no utility can be claimed4 ,thus the glories of sunrise and sunset1 which have delighted intelligent beings for so many ages1 are paintings upon the drapery of the firmament which the pencil of light has been enabled to produce through the medium of the refractive power of those gathering drops of water which float about in various forms and combinations in the morning or the evening sky4 ,it has already been more than once declared that carbon dioxide is poured out into the atmosphere by all the ordinary processes of combustion4 ,this is not only true of combustions such as those of coal and wood and similar highly carbonaceous materials2 it applies with equal force to the animal body itself1 which has been properly likened to a furnace4 ,the air taken into the lungs at each breath inspired1 supports during life a continual combustion1 by reason of which1 minute fragments of the animal tissue are burned in all parts of the system4 ,one of the products of this burning is carbon dioxide1 which is carried to the lungs1 thence to be exhaled as a waste product into the atmosphere4 ,it might at first be expected that this carbon dioxide would accumulate and form a constantly increasing proportion of the air4 ,but it is one of the proper foods of vegetable life2 for nature has wonderfully provided that plants should thrive by the absorption or inhalation of this particular gas4 ,and so all the leaves in the forest are continually cleansing the air of that carbon dioxide that living animals have cast aside as a useless thing4 ,and by a magnificent alchemy1 the result of a wonderful and beneficent plan1 they turn this waste matter of the animal frame into food for themselves1 and they cast out into the air as their refuse that oxygen gas which living animals demand4 ,so then the two forms of living beings exist in a harmonious partnership by reason of which each one is benefited4 ,an example similar to that just given with respect to carbon dioxide is found in ammonia gas4 ,this substance is one of the commonest products of the decay and decomposition of animal matters4 ,wherever animal waste is deposited upon the surface of the earth it quickly evolves ammonia gas4 ,this gas diffuses itself through the atmosphere under the influence of conditions whereby it may perform an important service2 for it is always extremely soluble in water4 ,and so as soon as rain is condensed1 whether in a gentle shower or in abundant torrents1 each drop in passing through the air gathers ammonia and carries it down to the earth4 ,again1 ammonia is one of the chief foods for plants4 ,and so the rain drops1 charged with such ammonia as they have been able to collect1 bear it to the rootlets in the soil1 as a valuable and important food1 and one which has been proved to have a most stimulating influence upon their growth4 ,there is not opportunity here for a discussion of the offices and the interplay of the other substances existing in atmospheric air2 for they are more local in their effects and more difficult to trace and to describe4 ,the ,air is not a ,chemical ,compound4 ,the importance of the atmosphere and its great abundance have naturally led to most thorough scientific scrutiny of it4 ,thus the amounts of its principal constituents have been studied with extreme care4 ,one result has been that the principal constituents--the oxygen and the nitrogen-- have been found to exist in air in proportions singularly constant in amount4 ,this fact indeed has suggested to some chemists the impression that air is a true chemical compound4 ,this latter suggestion appears not to be sustained by the most rigid examinations that have been made4 ,in fact they give ample support to the opinion already declared--that the air consists of a mass of merely mingled gases and that these gases are uniformly maintained in their proper proportional amounts by the beautiful interaction of the physical and chemical properties with which they are endowed4 ,fitness of ,atmospheric ,air for its ,uses4 ,the statements already presented must have suggested to the reader that the atmospheric air fulfils its offices in nature much as any contrivance carefully devised by an intelligent framer would accomplish the work for which it was planned4 ,beside those chemical adaptations which have been the principal grounds upon which this line of thought has been supported here1 there are others which may be briefly suggested4 ,by reason of the mobility of air1 as well as its tendencies to expansion by heat1 our atmosphere is necessarily in a state of most intricate ebbing and flowing4 ,one prominent effect of the motion thus set up is to cause a transfer of warm air1 and so a distribution of heat1 from more favored portions of the globe to the others4 ,this same result is also more completely attained by the influence of the specific heat of air4 ,atmospheric air has remarkable power1 in which it resembles to some extent water3 to take up a very large amount of heat with but a slight rise in temperature2 similarly a slight fall of temperature is associated with a large evolution of heat4 ,by reason of these properties1 air1 like water1 has an exceptional storage power for heat4 ,this contributes largely to the equalization of climates4 ,the elasticity of the atmosphere permits it to become a useful servant of man in the transmission of sound4 ,thus human beings--and with less distinctness most of the living creatures of the lower orders--communicate their thoughts by means of spoken words through that line of atmospheric air extending from them to their hearer or hearers4 ,again the characteristics of the atmosphere are such that it diffuses sunlight4 ,by this is meant that in air1 sunlight does not confine itself to those strictly straight lines which it follows in empty spaces4 ,so then this property of air mitigates the blackness of shadows and1 for example1 he who walks into a shady lane does not plunge into absolute darkness1 as he might if we were deprived of this beneficial diffusing influence of the atmospheric air4 ,the two considerations last adduced contribute much towards making the earth a cheerful home for human beings2 for they aid materially in the distribution of intelligible ideas4 ,moreover those properties of air by virtue of which its undulating waves makes music possible1 and further those which permit the flight of light1 and so allow of the existence of the graphic arts1 certainly make no mean contributions to the happiness of man2 and thus they help to furnish the earth as his place of residence4 ,illustration3 ,,fig4 #ec4--;,display of fireworks on the ,seine1 ,paris4 ,,chapter ,,xxi4 ,,explosives4 ,the principal explosives owe their activity1 to a very large degree1 to the presence of nitrogen in them2 thus they may properly be discussed in connection with that element4 ,the explosives of chief importance are four in number3 gunpowder1 the fulminates1 gun-cotton1 nitroglycerine4 ,while these substances suggest at once the war-like uses to which they are put1 it must not be forgotten that they have also important applications in the arts of peace4 ,thus enormous quantities of gunpowder and nitroglycerine are used in blasting operations for purposes like the removal of rock preparatory to laying foundations for large buildings1 as well as in excavations for railway cuttings and in the boring of tunnels2 also in the getting of building stone from quarries1 the tearing of ore out of mineral bearing veins in mining operations2 and for loosening coal in coal pits4 ,large quantities are likewise employed in pyrotechnics4 ,it must not be forgotten that fireworks are not only for purposes of night illuminations and for public gratification in times of popular rejoicings2 they are also employed to a considerable extent for such useful purposes as night signalling on vessels at sea4 ,gunpowder4 ,of the various explosives mentioned1 gunpowder is the oldest4 ,while the invention of this substance has often been referred to ,roger ,bacon1 the celebrated ,english friar who died about #abib1 it is now conceded that though ,bacon evidently knew the composition of it1 the original invention dates far earlier than his times4 ,there seems foundation for the belief that it is as old as a thousand years1 while its use by artillery at the battle of ,crcy shows its employment in warfare for over five hundred years4 ,bacon's power of independent thought1 placed him so far in advance of the century in which he lived that he became an object of persecution1 but he is at present ranked as one of the prominent figures of history4 ,in his works ,bacon refers to a substance that seems to correspond to gunpowder1 and in terms that suggest that he considered it as a material of not uncommon knowledge in his day4 ,illustration3 ,,fig4 #eb4--,roger ,bacon1 born near ,ilchester1 about #abad1 died probably at ,oxford1 in #abib4 ,the principal constituents of gunpowder are three3 potassic nitrate1 charcoal and sulphur4 ,the chemical action between potassic nitrate and charcoal in gunpowder may be better understood after a simple experiment1 which any one can try4 ,the experiment referred to is as follows3 take a large piece of charcoal2 heat it over a spirit lamp or gas lamp until certain portions of it take fire so as to burn with a slight glow2 next sprinkle very carefully a small amount of powdered potassic nitrate--also called both saltpetre and nitre--upon it4 ,a burning1 something like that of gunpowder1 only less violent1 results4 ,the potassic nitrate has the formula ,,kno4 ,when it falls upon the glowing coal a portion of the oxygen leaves the other constituents and accomplishes thereby a true combustion of the carbon4 ,one important factor in the operation is the element nitrogen2 owing to the general inertness of nitrogen it easily allows the escape of other elements combined with it4 ,so in case of the experiment just suggested1 the combustion of the charcoal is referable to oxygen liberated by reason of the feeble affinity of one of the other constituents of the potassic nitrate--that is1 the nitrogen4 ,thus far the only thing particularly suggested is the combustion that takes place2 another point of importance may be mentioned in this connection4 ,if finely powdered charcoal and potassic nitrate are thoroughly intermingled and then set on fire in a closed vessel1 a large amount of a gas1 that is1 carbon dioxide1 will be generated by the combustion2 and this gas may burst the vessel unless it is a very strong one4 ,if1 however1 the vessel has an opening supplied with a cork or plug1 this stopper will be violently driven out by reason of the explosive force of the carbon dioxide generated4 ,so in the preparation of gunpowder1 potassic nitrate1 charcoal and the third substance sulphur1 are finely pulverized and carefully intermingled4 ,thus they are brought to a state of thorough diffusion and intimate contact4 ,the offices of carbon and potassic nitrate have been already explained4 ,the office of the sulphur is principally to combine with the potassium of the potassic nitrate1 producing as a result a somewhat larger evolution of gas4 ,at all events1 when gunpowder is consumed1 two important results are afforded4 ,as already intimated1 the first is the sudden liberation of a very large amount of gas--carbon dioxide4 ,the second is that this gas is generated by a process of true combustion attended with great heat1 the latter contributing largely to the explosive force by reason of the great expansion of the gaseous products1 effected by the heating4 ,there are several different kinds of gunpowder1 but they all consist essentially of the constituents mentioned4 ,their differences are either in the proportions of the constituents used or in the size of the granules in which the powder is formed4 ,thus for some war purposes it is requisite that the powder should burn very rapidly1 while in others it is required to burn slowly4 ,for the purpose of regulating the rate of combustion1 the grains are made of various sizes4 ,the smaller sizes burn more quickly1 while those of larger dimensions as well as those more strongly compressed1 burn more slowly4 ,while the exact chemical changes which take place when gunpowder burns1 are too complicated to admit of discussion here1 they are in the main those just explained4 ,fireworks4 ,gunpowder affords the basis of the pyrotechnic art4 ,it is employed also with the distinct intention of utilizing both of those prime properties already referred to4 ,that is to say1 by reason of its explosive force1 gunpowder produces the various forms of motion requisite in fireworks4 ,by reason of the intense heat afforded by its combustion1 the various kinds of light are producible4 ,the truly marvellous effects obtained by the skilled pyrotechnist involve the use of a great multitude of substances and also an ingenious mechanical combination of them4 ,the effects he must produce require brilliant light in various qualities and also upon occasions loud reports1 as the bursting of bombs and the like4 ,so many forms and combinations of fireworks are possible that no enumeration can be made here2 moreover1 their infinite capabilities depend upon the inventive resources and skill of the maker4 ,in a brief description1 the rocket may be taken as the type of fireworks4 ,it is often of most ingenious construction4 ,thus it may be provided with many chambers1 one connecting with another by proper passages4 ,in these passages are placed fuses so that the fire shall run from one chamber to another in proper order4 ,of course the main barrel contains a quickly burning gunpowder4 ,this is for the purpose of producing the ascent4 ,it is well known that a pistol1 a rifle or a cannon1 always experiences a strong recoil when fired4 ,so does a rocket2 but the rocket is so constructed that the recoil is the chief factor in its first discharge4 ,that is1 if the rocket is compared to a cannon1 the discharge is downward and the recoil upward1 so that in fact the ascent of the rocket is due to what may be called an exceedingly powerful recoil4 ,when the rocket is high in air1 the fuse connected with its principal barrel lights its subordinate chambers1 and these then exploding distribute into the sky the brilliant masses of stars or other graceful pieces originally intended4 ,the loud reports that take place at such times are due to portions of violently explosive substances within certain chambers2 while the party-colored lights produced are referable to the burning of substances which have been carefully selected for the purpose4 ,thus the pyrotechnist has recourse to mixtures of gunpowder and various other chemical substances to produce colored fire4 ,finely powdered charcoal or lamp-black give rise to a red fire2 so also do most of the salts of strontium4 ,common salt or powdered rosin give rise to yellow fire4 ,copper filings and certain salts of copper produce greenish hues2 so do salts of barium4 ,zinc filings and chloride of copper1 and certain others1 produce blue shades4 ,saltpeter in considerable quantity affords a delicate pink2 while iron filings and steel filings produce scintillations of great brilliancy4 ,fulminates4 ,the fulminates are substances that are so extremely unstable in chemical character1 that they require but a very slight mechanical blow to decompose them4 ,two fulminates in particular may be mentioned3 fulminate of mercury and fulminate of silver4 ,they are both viewed as salts of a peculiar complex acid called fulminic acid4 ,this acid is a compound of carbon1 hydrogen1 oxygen and nitrogen4 ,when silver or mercury takes the place of the hydrogen in fulminic acid1 the dangerous salts just mentioned are obtained4 ,fulminating mercury is the one of chief use4 ,it is employed in percussion caps4 ,a drop of gum is put in the inside of the cap1 then the exact amount of fulminate in the form of a powder is allowed to fall into the gum2 finally the whole is allowed to harden4 ,when the cap is used1 a violent blow from the hammer of the gun or pistol gives rise to the explosion of the fulminate1 and this communicates to the gunpowder of the cartridge to be fired4 ,fulminating silver is too dangerous for use in percussion caps1 but it is employed in certain explosive toys like torpedoes4 ,gun-,cotton4 ,gun-cotton is a chemical modification of the ordinary cotton fibre4 ,this fibre when purified by chemical washings consists entirely of the substance called cellulose4 ,it is not different from certain other vegetable fibres4 ,it has the formula3 ,c,h,o,h which may also be represented as follows3 ,h ,h ,c,h,o ,h ,h ,h ,when clean cotton is acted upon by strong nitric acid it undergoes the wonderful chemical change to gun-cotton4 ,without material alteration in its physical appearance there has been a chemical substitution by reason of which a nitrogen compound has been introduced into the chemical molecule1 as a substitute in place of certain of the hydrogen atoms originally present4 ,thus the formula of gun-cotton may be represented as follows3 ,h ,h ,c,h,o ,,no ,,no ,,no ,a comparison of this formula with the one given for pure cotton shows that three atoms of hydrogen in the cotton have been replaced in the gun-cotton by three molecules of the compound radicle ,,no4 ,on this account gun-cotton is often spoken of as trinitrocellulose4 ,by reason of this chemical substitution the cotton changes as if by magic from the simple1 safe material ordinarily known1 to one of the most dangerous of explosives4 ,thus ,mr4 ,abel1 the chemist to the ,english ,war ,department1 who has made a series of most careful studies of gun-cotton with reference to its use for war purposes1 finds the explosive power of gun-cotton to be more than fifty times that of gunpowder of equal weight4 ,one of the greatest objections to the use of gun-cotton is found in the fact that upon keeping1 it undergoes of itself a steady decomposition resulting ultimately in dangerous explosions4 ,this fact appears to be likely to prevent the substance coming into general use4 ,illustration3 ,,fig4 #ed4--;,establishment for manufacture of dynamite1 near ,turin4 ,nitroglycerine4 ,glycerine--produced at present in enormous quantities from fats and oils--is well known as a sweetish1 oily and harmless substance4 ,glycerine is composed of carbon1 hydrogen and oxygen in proportions but slightly different from those in cotton4 ,thus its formula is ,c,h,o,h4 ,if this bland and simple material is subjected to the action of concentrated nitric acid1 it undergoes a change very similar to that recognized in the case of cotton and just described4 ,it then produces a compound called trinitroglycerine which1 while it ranks as one of the most powerful and useful explosives1 is also associated with a long list of horrible disasters produced by accidental1 or in some cases intentional1 explosion of it4 ,nitroglycerine is itself an oily material and was at first considerably used in that form4 ,the terrible accidents from transportation of the article have given rise to the adoption of two means for lessening the risks attending it4 ,the first is the manufacture of the substance in suitable localities--that is near to great public works in which it is to be employed4 ,and again the factories are so arranged that the operation of the manufacture shall be conducted in small buildings surrounded by earthworks sufficient to localize any explosion that might unhappily occur4 ,at the manufactory of explosives at ,ardeer on the ,scotch coast1 about fifty miles from ,glasgow1 a most ingenious additional precaution is taken4 ,here each laborer1 as he enters the works in the morning1 passes into a cottage to change his dress4 ,he dons a uniform of a special and distinctive color--it may be scarlet1 or bright blue or white or gray1 according to the department in which he is employed4 ,thus the policemen who are constantly on duty can detect at once any employ who strays into a department to which he does not belong and where his lack of acquaintance with the processes might lead to a terrible accident4 ,illustration3 ,,fig4 #eg4--,torpedo-boat attacking a large war vessel4 ,another special device is the invention of ,albert ,nobel1 who has been noted as the principal person by whose efforts nitroglycerine has been introduced into the important uses which it finds at the present day4 ,this is the absorption of the liquid nitroglycerine in some spongy material such as will serve as a safe and proper vehicle for the explosive4 ,the substance thus employed is a kind of fine siliceous earth called diatomaceous earth1 also infusorial earth4 ,this is a mineral material found in various parts of the world in somewhat abundant deposits4 ,upon examination by the microscope it is found to be composed of the mineral skeletons of microscopic organisms4 ,the minute cellular texture which this substance affords seems to be admirably fitted to imbibe the liquid nitroglycerine1 and assist in packing it in proper cartridges4 ,the explosive produced by the combination is the one commonly known as dynamite4 ,illustration3 ,,fig4 #ef4--;,dynamite exploder4 ,a peculiarity of nitroglycerine and dynamite is that they cannot be fired in the ordinary fashion4 ,that is1 if a lighted match is brought to them they may take fire and burn with perfect quietness4 ,for their explosion they demand some kind of violent blow4 ,for this reason their cartridges have to be provided with special exploders4 ,these are small cases of gunpowder or perhaps fulminating materials1 which may be set on fire by means of a powder fuse or an electric current2 their explosion within the nitroglycerine mass determines a violent shock to the latter4 ,it is the concussion thus produced that is the appropriate means of exploding the nitroglycerine or dynamite cartridges4 ,while the sad accidents with these materials have horrified the whole world by their sudden and disastrous results it is too often forgotten that their gigantic forces are day by day safely and quietly contributing to the execution of great public works all over the earth4 ,thus in the great rock tunnels of ,mont-,cenis and ,st4 ,gothard1 which pierce the ,alps1 nitroglycerine and dynamite have done the work of armies of men4 ,in the ,st4 ,gothard tunnel more than two million pounds of dynamite have been employed1 and it has proved wonderfully effective in advancing most arduous subterranean work4 ,unquestionably the principal use of this explosive1 as well as others1 is in the labors of peace4 ,still1 nitroglycerine and dynamite have come into great prominence by reason of their use in naval warfare4 ,torpedoes of a great variety of forms are now constructed so that a quick moving launch may steam up to a large ship of war1 place close to her side one of these dangerous contrivances and then quickly withdraw in time to avoid the effects of the explosion which involves the great vessel in devastating ruins4 ,torpedoes charged with nitroglycerine or dynamite1 are also used for the defence of harbors1 being sometimes placed in such a way that an enemy's ship1 in crossing the line formed by the torpedoes1 shall by that act explode one or more of them and produce her own destruction4 ,,reading ,,references4 ,explosive ,agents4 ,abel1 ,f4 ,a4--,jour4 of ,chem4 ,soc4 of ,london4 xxiii1 #da1 xxvii1 #ecf4 --,chem4 ,news4--xxxix1 #afe1 #ahg1 #aih1 #bjh4 ,explosives1 a ,new ,class of ,sprengel1 ,h4--,jour4 of ,chem4 ,soc4 of ,london4 xxvi1 #gif4 ,explosives1 ,force of ,berthelot4--,annales de ,chimie et de ,physique4 #d ,sr4 xxiii1 #bbc4 ,explosives1 in ,blasting4 ,scribner's ,monthly4 iii1 #cc4 ,greek ,fire1 7so called47 ,lalanne1 ,l4--,annales de ,chimie et de ,physique4 #c ,sr4 iv1 #dcc4 ,gun-cotton1 ,manufacture and ,composition of ,abel1 ,f4 ,a4--,journal of ,chem4 ,soc4 of ,london4 xx1 #caa1 #eje4 ,gunpowder1 ,chemical ,theory of ,debus1 ,h4--,chemical ,news4 xlv1 #ia4 ,,chapter ,,xxii4 ,,phosphorus4 ,phosphorus is a most interesting chemical element4 ,this is because of its exceptional chemical properties1 the very important part it plays in the chemistry of animal and vegetable life1 and its employment in the friction match1 one of the most convenient and useful articles of human invention4 ,phosphorus appears to have been first prepared in the year #affi by a ,hamburg merchant named ,brandt who became fascinated with the study of alchemy and pursued his experiments with the view of repairing his broken fortunes by the discovery of the philosopher's stone4 ,the happy discovery of phosphorus1 while it did not enrich him1 at least preserved his name in the annals of chemistry4 ,brandt produced it by a laborious process from certain animal matters4 ,notwithstanding the remarkable properties of the substance and the extraordinarily useful purposes to which modern scientific knowledge has applied it and its compounds1 phosphorus remained the merest toy for more than a hundred years4 ,in #agga ,scheele revealed to the world the fact that it may be prepared from bone-ashes1 that is from burnt bone1 and this has ever since been found to be its most convenient source4 ,the name phosphorus is derived from two ,greek words 7 phos1 light1 and1 phero1 ,i bear7 which suggest one of its marked properties1 namely its power of continually affording light even though not set on fire after the manner of ordinary illuminating materials4 ,it is true the light is feeble and chiefly noticeable in the dark4 ,it is the same1 in fact1 as that yielded in the dark by an ordinary friction match when it is gently rubbed1 but has not yet taken fire4 ,this light1 however1 is the product of a true combustion1 only of a very slow one2 and again this burning of phosphorus is initiated by heat1 7though only a very moderate amount is required for it74 ,of course for phosphorus much less heat is demanded than to set on fire our ordinary combustibles4 ,phosphorus1 though very widely distributed in nature1 is never found free or uncombined4 ,this fact is distinctly referable to the ease with which the substance combines with oxygen2 if it were found free at any point on the surface of the earth1 where it suffered exposure to atmospheric air1 it would of course quickly enter into combination with oxygen4 ,phosphorus exists occasionally in the earth in the state of combination in very hard rocky masses1 of which the mineral known as apatite--composed mainly of calcic phosphate--is a good example4 ,it is also present in small quantities in almost all soils2 and in minute quantities in most natural waters1 like river-water and sea-water4 ,one of the most familiar substances containing phosphorus is the bony skeleton of the higher animals4 ,here also it exists as calcic phosphate4 ,it exists also in the brain1 though in a form of chemical combination not easily stated4 ,further1 it is a constituent of various portions of the vegetable structure1 especially of seeds4 ,the statements in the last two paragraphs have been presented with the express purpose of calling attention to the important offices of phosphorus in connection with animal and vegetable life4 ,thus exact experiments have shown that plants cannot flourish in soils barren of phosphates1 and that the mere addition of almost any soluble phosphate to an arid soil promptly stimulates the plant living upon it1 into more luxuriant growth4 ,these facts have led to the introduction into commerce of artificial fertilizers containing soluble phosphates as their principal ingredients2 and the manufacture of such fertilizers has continually expanded1 until now it is conducted by the principal commercial nations on a truly gigantic scale4 ,for the purpose of this manufacture1 bones are particularly favorable because of their porosity4 ,in fact the surface of the world is ransacked to supply this raw material4 ,thus from the deserts of ,africa1 bones are conveyed as far as ,england to be manufactured into fertilizers2 and so from the great western plains of the ,united ,states1 bones are brought to the eastern centres for a like use4 ,the agricultural demand for phosphates of some sort has become so imperious that even apatite is now largely used1 notwithstanding the difficulties that its exceedingly hard and compact structure place in the way of the manufacturer4 ,from the plant1 phosphorus finds its way in the form of food into the animal system4 ,the living animal appreciates this essential ingredient1 carefully selects it out from the food1 and stores it up both in its brain and in its bony framework4 ,this framework is exceedingly important as giving the requisite rigidity to the whole structure1 and the proper support for the action of the various muscles4 ,phosphorus itself is prepared by a process too complicated for the ordinary amateur chemist to repeat2 indeed its preparation1 even on the large scale1 presents serious difficulties4 ,these are associated with the great combustibility of the substance1 which makes necessary extraordinary precautions against fire4 ,again1 laborers in phosphorus works are subject to a painful and incurable disease called phosphorus necrosis1 which has a peculiar and destructive effect upon the bones of the jaw4 ,finally1 the chemical changes involved give rise to such difficulties and complexities as force the manufacturer to unusual watchfulness4 ,in fact it has been recently stated that there are scarcely more than two factories for phosphorus manufacture in the world--one in ,england and one in ,france4 ,the element phosphorus1 as ordinarily seen1 has much the appearance of wax4 ,it has a white or amber color1 and is translucent2 it may be cut with a knife much as wax cuts4 ,it is ordinarily sold in the form of cylinders of about half-an-inch in diameter4 ,it is necessary to keep it in vessels of water1 for as already stated1 if exposed to the air it would oxidize4 ,this oxidation1 at first slow1 increases in vigor from the heat afforded by the earlier stages4 ,after a short exposure to air1 portions of phosphorus spontaneously burst into flame4 ,evidently then1 phosphorus should not be handled except under water4 ,cases are recorded of severe and even fatal burns--the result of handling phosphorus in the air4 ,we may with propriety call attention here to another peculiarity of phosphorus1 which constitutes one of the remarkable features of this interesting element4 ,about thirty years ago1 a ,vienna chemist discovered that when phosphorus is heated for a considerable length of time1 under conditions such that no gas is present which can act chemically upon it1 it undergoes a marked change in its properties4 ,thus its color turns to red1 and1 strange to say1 it loses altogether that ready combustibility which is the most striking characteristic of ordinary phosphorus4 ,it may seem incredible that any such change could in fact occur4 ,but this red phosphorus has become an article of considerable importance in commerce1 and it is a well-established fact that ordinary phosphorus may be turned into this modification without any gain or loss of weight1 and that1 on the other hand1 this red phosphorus may be turned back again1 by suitable processes1 to the ordinary form1 also without gain or loss of weight4 ,phosphorus is not the only elementary substance that is capable of this kind of change4 ,indeed the general term allotropism has been applied to the tendency of elementary substances to undergo internal changes1 by reason of which their chemical properties are temporarily modified without gain or loss of weight1 and therefore independently of chemical combination or decomposition4 ,illustration3 ,,fig4 #eh4--;,coignet's apparatus for production of red phosphorus4 ,ordinary phosphorus is placed in a cast-iron vessel c2 it is then heated ten or twelve days1 an even temperature being maintained by the two iron jackets1 one enclosing sand1 the other holding fusible alloy4 ,chemical ,properties of ,phosphorus4 ,the chemical properties of phosphorus are wide in their range2 that is1 it combines with many of the chemical elements4 ,thus it unites with hydrogen in more than one proportion1 and thereby forms several compounds4 ,as might be expected1 they are all exceedingly combustible2 one of them in particular1 called phosphuretted hydrogen1 takes fire at ordinary temperatures immediately upon coming in contact with the atmosphere4 ,its production affords opportunity for a beautiful experiment1 though a somewhat dangerous one4 ,when the gas is produced in a retort1 it may be made to bubble through water in the form of vapor in company with various gases generated at the same time4 ,then1 as it reaches the surface1 it instantly takes fire1 the phosphorus burning to a white1 smoke-like substance which usually floats away in forms similar to those of smoker's rings4 ,the smoke consists of minute particles of a solid1 called phosphorus pentoxide1 and expressed by the formula ,p,o4 ,this is evidently the product of the combustion of that phosphorus which is a part of the inflammable gas4 ,the shape of the rings is due to a mere mechanical circumstance and the same in effect as that afforded by the lips of the smoker while producing rings4 ,indeed if a paper box1 having a round hole on one side1 be filled with smoke of any kind1 sharp blows upon the opposite side will drive out portions of the smoke in such a way as to produce similar rings4 ,such rings are often seen on a still day puffed out of the smokestack of a locomotive1 and they are sometimes produced by the discharge of a cannon in still air4 ,the fact is that in all these cases the portion of smoke producing a ring advances through the opening with a sudden impulse1 the edge of the opening retarding those particles that pass nearest to it4 ,thus the delayed particles acquire a tendency backward and inward which starts them on the peculiar series of circular courses1 which in the grand aggregate give rise to the rings4 ,illustration3 ,,fig4 #ei4--,phosphuretted hydrogen gas1 of the spontaneously inflammable variety1 taking fire in air and forming smoke-rings4 ,as has more than once been stated1 phosphorus has a marked affinity for oxygen4 ,it burns in any vessel containing air1 combining with oxygen in such a way as to readily deprive the air of the entire amount of this element contained in it4 ,the chemical change is represented by the following equation3 ,p #e,o #b,p,o ,one molecule of ,five molecules of ,two molecules of ,phosphorus1 ,oxygen1 ,phosphorus pentoxide1 #abd #afj #bhd parts by weight4 parts by weight4 parts by weight4 _/ _/ #bhd #bhd ,when the operation is performed in a tall jar1 the oxide of phosphorus produced falls as abundant flakes having a snow-like consistency4 ,when these flakes are thrown upon water they chemically combine with the water1 affording much heat and producing a hissing sound which is the evidence of it4 ,the liquid now acquires a sour taste referable to the fact that phosphoric acid has been produced4 ,the chemical change is represented by the following equation3 ,p,o #c;,h,o #b;,h,,po ,one molecule of ,three molecules of ,two molecules of ,phosphorus pentoxide1 ,water1 ,phosphoric acid1 #adb #ed #aif parts by weight4 parts by weight4 parts by weight4 _/ _/ #aif #aif ,phosphoric acid is the starting point of an immense series of salts called phosphates4 ,one of these1 calcic phosphate1 we have already referred to as existing in bones and in apatite4 ,friction ,matches4 ,the earliest method of producing flame appears to have been by the friction of pieces of dry wood in contact with dry leaves or similarly combustible substances4 ,this method travelers have found to be still in use among tribes of a low stage of development4 ,the next method seems to have been by the use of flint and steel and tinder4 ,when the flint is sharply struck against the steel1 it tears off minute particles of the metal1 and these fragments are heated to the luminous point by the violence of the stroke2 if they are made to fall upon the tinder1 this easily combustible material takes fire2 from its burning1 a candle or lamp may be lighted4 ,but the flint and steel and tinder must be dry and in good order to produce the best results2 even then considerable skill is demanded4 ,so it is easy to see that mankind has often preferred to preserve a flame once lighted1 and then communicate this to another and another from time to time1 rather than to go to the trouble of exciting a new combustion when fire was needed4 ,and it is easy to appreciate the usefulness to its possessor of a flame once kindled--and the serious inconvenience resulting from its extinction4 ,thus we can readily comprehend how nations have adopted fire as a sacred agent1 to be preserved continuously unextinguished1 and to be guarded with religious care4 ,the flint and steel method has ample illustration as to its principle1 not only in familiar cases like sparks from the horse's hoof1 but also in many processes in factories and machine shops4 ,here it is well known that the grindstones used for finishing articles of iron and steel send off from their work an uninterrupted current of minute chips of the hot and luminous metal4 ,the flint and steel method of obtaining fire held its own until about sixty years ago4 ,in #ahbi a kind of chemical match was devised1 and soon after1 in #ahcb1 a true friction match containing phosphorus was brought into use4 ,the principles upon which the phosphorus match depend are but very slightly different from those involved in the use of the flint and steel4 ,thus in the friction match the rubbing upon the rough surface is a mechanical process which generates heat1 just as any blow or any friction does4 ,in the case in question the amount of heat is small1 but it is sufficient to set on fire the small amount of phosphorus on the tip of the match2 the phosphorus sets on fire the sulphur which coats over the end of the match2 the sulphur in burning sets on fire the wood of the match1 and here the combustion has reached a stage at which it is easily communicated to larger masses of material4 ,in the finer kinds of wooden matches1 in order to avoid the objectionable smell of the burning sulphur1 this latter substance is sometimes replaced by a thin coating of wax upon the end of the stick4 ,in this case1 other chemicals are added to the tip of the match1 in order to make the combustion more active4 ,friction matches of the ordinary kind are now so abundant and familiar everywhere that the exceeding usefulness1 convenience and importance of the match as a device or invention1 is apt to be overlooked4 ,it is not intended to dwell here upon this subject1 however1 for perhaps what has been said of the appliances for lighting used in the past1 renders unnecessary further presentation of the principles utilized in the little tapers of to-day4 ,as an article of manufacture1 the individual match is so small that it is not easy at first to appreciate the greatness of the commercial interest it represents4 ,thus it is estimated that in ,europe alone fifty thousand persons are constantly employed in the manufacture of the various kinds of matches4 ,again1 though the amount of phosphorus used in each match is very minute1 its sum total is no less than a thousand tons a year4 ,the value of the annual product of this industry is not far from fifty millions of dollars4 ,if there were introduced here an account describing at length the manufacture of the friction match--commencing at the beginning with the special kind of wood employed and the processes used for its subdivision into the requisite fragments1 continuing even so as to explain the various contrivances for packing the finished product--that description might be of interest2 but the special topic seems to be more properly the preparation and application of the material at the tip of the match4 ,the sticks having been prepared1 they are placed1 by machine1 in frames capable of containing large numbers of them4 ,they are first sulphured1 that is their ends are dipped in melted sulphur and it is allowed to harden upon them4 ,for the finer grade of matches however1 the sulphur must be dispensed with1 and instead the sticks are dipped into melted wax4 ,in any case1 they are next tipped with the highly inflammable material1 this process being called chemicking4 ,the inflammable paste is prepared in large quantities by mixing the proper ingredients in a kettle surrounded by boiling water4 ,first1 a solution of an appropriate gum or glue is made4 ,when it has attained a proper consistency1 the phosphorus is introduced little by little4 ,the whole mass is then slowly but thoroughly agitated with a wooden stirrer until thephosphorus is diffused through the mass4 ,finally1 other ingredients1 such as potassic nitrate or binoxide of lead or manganese dioxide1 which favor combustion1 are added2 and certain coloring matters1 such as ,prussian blue or vermilion1 are introduced4 ,here is a ,german recipe for making this paste3 ,gum1 #af parts4 ,phosphorus1 #i parts4 ,potassic nitrate1 #ad parts4 ,manganese dioxide1 #af parts4 ,as has already been intimated1 all of these substances1 except the phosphorus1 may be replaced by others1 according to the style of the article to be manufactured or the views of the maker4 ,the process of chemicking consists in dipping the sulphured ends into the inflammable paste1 which for this purpose is spread out on a stone slab4 ,finally1 the tips are coated over with a thin varnish to protect them from absorption of moisture4 ,illustration3 ,,fig4 #fj4--,pan or water-bath1 for melting and mixing the inflammable paste for match tips4 ,at present the manufacture of friction matches is carried on to a very large extent in ,sweden1 and that country1 it is now stated1 produces about seventy-five per cent of all the matches made in the world4 ,in ,sweden1 too1 are largely manufactured what are called safety matches4 ,the safety matches are tipped with a composition of potassic chlorate1 potassic dichromate1 red oxide of lead1 and sulphide of antimony4 ,under ordinary circumstances friction will not set these matches on fire4 ,in lighting1 they must be rubbed on a prepared surface which contains principally red phosphorus and sulphide of antimony4 ,when the match is rubbed upon this surface1 the potassic chlorate of the match and the red phosphorus of the friction-surface start a chemical combination which extends to the other materials on the tip of the match4 ,safety matches1 then1 involve an invention which in accomplishing its purpose1 affords a twofold advantage4 ,in the first place1 as the match lights only on the prepared surface1 the danger of conflagrations from accidental ignition of them is very largely reduced4 ,this costly feature of the ordinary phosphorus match would be largely1 if not entirely1 done away with by the general use of the safety match4 ,in the second place1 the use of red phosphorus has the advantage of saving human lives in other ways4 ,thus it spares the operatives1 employed in this business1 the liability to the phosphorus disease already mentioned4 ,again1 ordinary phosphorus is very poisonous2 in fact the tips of matches containing this substance have not only often produced the death of children who have tasted them1 but such matches have often been used in cases of intentional suicide4 ,of course as safety matches contain no phosphorus1 these forms of poisoning cannot arise from them4 ,a flame of fire1 as a visible and tangible thing1 has in all ages been accepted as a symbol which appropriately typifies enlightenment of the mind and soul4 ,this favorite and beautiful figure loses none of its fitness when narrowed in its application to the aspects of these subjects in their peculiarly modern forms4 ,for in the friction match1 whose cheapness brings it to the hand of every human being however low his degree1 we may discover the type of that opportunity for enlightenment offered to individuals whose circumstances seem most humble and even forbidding4 ,the one is the invention of modern science2 the other the gift of modern laws1 of modern theories of the rights of men1 of modern schools1 libraries1 and newspapers1 of the modern printing press1 telegraph1 and railroad4 ,,reading ,,reference4 ,friction ,matches4 ,schrtter1 ,a4 ,v4--,chem4 ,news4 xxxvi1 #bjg1 #bai1 #bei4 ,,chapter ,,xxiii4 ,,carbon4 ,carbon exists in nature in a multitude of forms4 ,it is rarely found in the pure and uncombined condition1 though certain well-known substances possess it in large quantity4 ,ordinary ,charcoal4 ,illustration3 ,,fig4 #fa4--;,charcoal pit4 ,probably the most familiar and representative form of carbon is that known as charcoal4 ,but charcoal is rarely free from other chemical elements1 and a distinction ought to be made between it and the absolutely pure form of the element under consideration4 ,charcoal is produced by the partial decomposition1 under the influence of heat1 of vegetable or animal substances4 ,thus charcoal is commonly prepared by piling wood into a conical heap1 then covering it with earth and sods1 and finally setting it on fire within4 ,certain portions of the wood are thus burned1 while others are only charred4 ,the wood is decomposed by the heat to which it is subjected2 volatile materials generated by this decomposition are expelled1 while there is left behind a solid matter consisting mainly of carbon1 and called charcoal4 ,illustration3 ,,fig4 #fb4--,tree trunks discovered in coal mines4 ,animal ,charcoal4 ,the same general treatment of certain animal matters1 such as waste leather1 gives rise to a finer kind of carbon called animal charcoal4 ,illustration3 ,,fig4 #fc4--;,charcoal burners at work4 ,again1 when bones are partly burned1 they produce what is called bone-coal4 ,the mineral matter of the bone undergoes no change by the heat2 but the gelatinous matters which permeate it are decomposed1 and they leave behind them the carbon deposited upon this mineral matter4 ,lamp-,black4 ,another material1 closely assimilated to those already spoken of1 is lamp-black4 ,this is a product of the imperfect combustion of substances like oil1 tar1 resin1 and the like1 which are very rich in carbon4 ,the tar or resin being set on fire is allowed to burn1 but in an imperfect way1 and so as to evolve a dense black smoke4 ,the smoke flows into a chamber prepared for it1 where the sooty material collects on the floor and walls4 ,it is afterwards scraped up and put into packages for commercial distribution4 ,in the ,english method of manufacture of lamp-black1 the smoke is made to pass through a series of heavy canvas bags4 ,from openings at the bottoms of the bags1 the soot is afterward drawn out for packing4 ,illustration3 ,,fig4 #fd4--,manufacture of lamp-black4 ,illustration3 ,,fig4 #fe4--;,bags in which lamp-black is collected in the ,english process of manufacture4 ,coal4 ,anthracite coal and bituminous coal are both well-known compounds of carbon4 ,anthracite seems to be derived from bituminous coal which has been subjected in the earth to heat and pressure under conditions favorable to the expulsion of some of the more volatile constituents of the original bituminous coal4 ,both of these combustibles1 when carefully studied1 show distinct evidences of their vegetable origin4 ,plainly they are accumulated masses of the remains of a rank vegetation which flourished in an earlier period in the geological history of our globe4 ,careful observations made in the mines have revealed in the coal the existence of trunks of trees1 branches1 leaves1 fruits1 in various conditions from the one extreme of comparatively perfect preservation1 to the other extreme in which the mineral preserves a mere impression of the original vegetable matter4 ,these remains have made it possible to construct a complete botany of this period of geological history2 and with but a moderate aid of the imagination1 artists have been able to produce ideal landscapes representing these early forms of vegetable life as they flourished in the ancient ages4 ,illustration3 ,,fig4 #ff4--;,imaginary landscape during the carboniferous era4 ,graphite4 ,closely allied to anthracite coal is that valuable material called graphite4 ,this a very compact and comparatively pure form of carbon4 ,it is familiarly known to every one in the black material used in lead pencils4 ,graphite is commonly called black lead1 though it is a well established fact that it contains no lead at all4 ,strangely enough graphite is remarkably incombustible under all ordinary circumstances4 ,it is also--like other forms of carbon--infusible at the highest temperatures known4 ,on account of these properties graphite finds use1 though it must be deemed a somewhat anomalous one1 in the manufacture of crucibles4 ,when the precious metals are fused in such a crucible1 at a high temperature in a glowing furnace1 an interesting paradox is furnished4 ,it is this3 the coal--freely burning in the fire1 and so furnishing the intense heat desired--is fundamentally of precisely the same chemical nature as the graphite of the crucible1 which resists the heat and the combustion1 and1 while allowing the metals to melt1 preserves them4 ,the ,diamond4 ,the diamond is nearly pure carbon1 crystallized4 ,perhaps it is not too much to say that it is the most striking and wonderful of all the forms of this interesting element4 ,the costliness of the diamond is referable largely to its great rarity2 for it is found in comparatively few portions of the earth4 ,the ancient ,greeks and ,romans highly prized the rare and precious crystal1 which they obtained from ,india1 and it was worn by them not only because of its costliness and beauty1 but also because they believed that it served as a potent charm against alarms and enchantments2 more important yet1 they ascribed to it the power of preserving the peace and harmony of the family circle4 ,upon this point a ,french writer has wittily said3 8,cette dernire vertu1 je crois qu'il la possde encore quand le mari est assez riche pour acheter le bijou que sa femme ambitionne de porter60 ,the ,east ,indies1 the ,cape of ,good ,hope and the ,brazils may be said to be the principal sources of this gem4 ,in ,brazil the search for diamonds is systematically conducted4 ,the diamond bearing soils are carefully pulverized in vessels of water1 under the direction of experienced inspectors4 ,the work is done by slaves who prosecute their search under the stimulus of the well understood rule that he who finds a diamond weighing seventeen and one-half carats or more1 publicly receives his freedom as a reward4 ,notwithstanding the systematic labor applied to the search for these gems and the fascination naturally attending undertakings of this sort1 the wealth of ,brazil is derived to a vastly greater extent from its agricultural products than from its mines4 ,thus it is stated that from #agdj to #ahbb1 a period of more than eighty years1 the diamond mines yielded but little more than #ag1jjj1jjj4 ,on the other hand the value of coffee exported in a single year has sometimes been double or even more than double this amount4 ,thus in the year #ahei the coffee exported was valued at above #bh1jjj1jjj2 and in #ahgc the quantity of this article exported was valued at above #fj1jjj1jjj4 ,illustration3 ,,fig4 #fh4--8,the ,sancy40 ,illustration3 ,,fig4 #fi4--8,the ,polar ,star40 ,illustration3 ,,fig4 #gj4--8,the ,empress ,eugenie0 or 8,pigott40 ,illustration3 ,,fig4 #ga4--8,the ,koh-i-noor40 ,illustration3 ,,fig4 #gb4--8,the ,star of the ,south40 ,illustration3 ,,fig4 #gc4--8,the ,regent0 or 8,pitt40 ,illustration3 ,,fig4 #gd4--8,the ,grand ,duke of ,tuscany40 ,illustration3 ,,fig4 #ge4--8,the ,orloff40 ,illustration3 ,,fig4 #gf4--8,the ,grand ,mogul40 ,the great diamonds of the world 7natural size74 ,illustration3 ,,fig4 #gg4--,transportation of diamonds under military protection4 ,illustration3 ,,fig4 #gi4--;,diamond cutter at work4 ,the larger gems are exceedingly rare4 ,on this account the money value of diamonds increases in a far more rapid ratio than the weight4 ,the ,cutting of ,diamonds4 ,illustration3 ,,fig4 #hj4--;,diamond known as 8,the ,star of the ,south02 before and after cutting4 ,the cutting of diamonds as an art has been known for but a few centuries1 and the perfection with which it is at present conducted is of much more recent date4 ,of course the process is an extremely delicate and important one because it involves splitting off portions of the gem so as to reduce it to the exact geometrical shape previously decided upon4 ,that form called the brilliant is the one commonest produced at the present day4 ,the business of cutting diamonds has been for a long time concentrated in the city of ,amsterdam in ,holland4 ,here1 among a ,jewish population of twenty-eight thousand persons1 ten thousand are employed exclusively in working on diamonds4 ,in many cases diamonds are subject to a very large relative loss of weight by the process of cutting4 ,thus the ,koh-i-noor1 when brought from ,india as a gift from the ,east ,india ,company to the ,english ,crown1 was in the rough state and weighed one hundred and eighty-six carats4 ,it was afterwards cut in ,amsterdam1 by which process it suffered a loss of weight variously stated as from eighty to one hundred carats4 ,after the first trimming1 the gem is carefully polished by rubbing it gently against a revolving plate upon which is a mixture of oil and diamond dust4 ,illustration3 ,,fig4 #ha4--;,diamond polisher at work4 ,illustration3 ,,fig4 #fg4--;,diamond washing in ,brazil4 ,up to the close of the last century the nature and composition of the diamond had been a subject of interesting discussion among students of natural science4 ,at the period mentioned however1 the question was settled by ,lavoisier and other scientific investigators1 who clearly proved that the diamond underwent complete combustion in oxygen and that as a result carbon dioxide gas was generated4 ,illustration3 ,,fig4 #hb4--,the ,koh-i-noor before cutting4 ,illustration3 ,,fig4 #hc4--,the ,koh-i-noor after cutting4 ,other ,natural ,forms of ,carbon4 ,in addition to the well-known forms of matter containing carbon1 and already described1 there are yet many others4 ,thus it is found in the atmosphere1 as has already been explained1 in the form of carbon dioxide4 ,this gas exists in the air in small relative proportion1 but in enormous aggregate amount4 ,as a natural carbonaceous substance petroleum1 too1 ought not to be forgotten4 ,this wonderful and useful substance stored up beneath the surface of the earth1 in incredibly large quantities1 owes its chief value to its wealth of carbon4 ,it is composed of carbon and hydrogen1 but the former is the constituent to which is referable the beautiful light it affords4 ,again1 the marble and the limestones of the globe contain enormous quantities of carbon4 ,these minerals consist principally of calcic carbonate 7,ca ,,co72 and the carbon makes up about one-eight of this substance4 ,since some whole mountain chains consist chiefly of limestone or marble1 it is plain that the total amount of carbon in these forms must be very large4 ,illustration3 ,,fig4 #hd4--,view in the vicinity of the ,pennsylvania oil wells4 ,with few exceptions1 all animal and vegetable matters contain carbon--a substance which appears to perform its most important offices in connection with the kingdoms of life4 ,indeed it has been called the characteristic element of animal and vegetable compounds4 ,so vast is the variety of these compounds already recognized that it is hardly conceivable that man can ever be able to acquire an acquaintance with all those as yet undetected4 ,illustration3 ,,fig4 #he4--;,automatic regulator whereby the carbon pencils of the electric light are maintained at the proper distance apart4 ,infusibility of ,carbon4 ,carbon differs from most solid substances in the fact that it is infusible at the highest temperatures to which it has yet been subjected4 ,and since in the elementary form it has not been changed to the liquid state1 much less has it been brought to the gaseous condition4 ,indeed this stability and fixedness of carbon is one of its most valuable attributes4 ,thus this characteristic is a principal one that renders it specially appropriate for use in the pencils employed in electric lighting4 ,it is true these pencils slowly burn away4 ,but some combustion ought to be expected when it is remembered that the electric current1 flowing from one pencil to the other1 affords an intense heat as well as brilliant light4 ,but it is a general law that substances give out the most intensely brilliant white light when they neither liquefy nor volatilize1 and to this principle--exemplified in the carbon pencils--must be referred the brilliancy of the electric light4 ,decolorizing ,power of ,carbon4 ,carbon1 whether in the form of wood charcoal1 animal charcoal1 or bone-coal1 has a wonderful power of decolorizing liquids4 ,even more compact carbonaceous matter1 such as anthracite coal1 possesses this same property though1 as might be expected1 to a much inferior degree4 ,thus if a colored solution is strained through a considerable quantity of one of these forms of carbon1 the latter substance absorbs the coloring matter and the liquid passes through practically colorless4 ,on account of this wonderful power bone-coal is used in the arts in enormous quantity in many processes where liquids must be decolorized4 ,the sugar refining industry affords a prominent example upon this point4 ,here1 enormous quantities of bone-coal are used for the purpose of whitening the syrups before crystallizing the sugar4 ,illustration3 ,,fig4 #hf4--,magnified view of the carbon terminals used for the production of the electric light4 ,illustration3 ,,fig4 #hg4--;,excavations carried on at night by aid of the electric light4 ,charcoal has also a similar1 and yet more striking1 property of absorbing offensive gases4 ,thus1 tainted meat packed in freshly burned charcoal quickly loses its odor--which is absorbed by the coal--and the meat then becomes sweet and wholesome4 ,chemical ,properties of ,carbon4 ,the chemical properties of carbon are by no means less wonderful than the characteristics already referred to4 ,it is very inert at low temperatures2 but at high temperatures1 it manifests chemical activities of extraordinary vigor4 ,thus at high temperatures carbon withdraws oxygen from almost any other elements known1 in this way manifesting chemical force superior to that possessed by any of them4 ,illustration3 ,,fig4 #hh4--;,colored liquid filtered through charcoal1 and thereby decolorized4 ,the ,great ,number of ,compounds ,formed by ,carbon4 ,the vast number of the compounds of carbon seems to be referable to two fundamental properties with which it is endowed by nature4 ,one of these is the fact that the atom of carbon possesses four points of attraction4 ,this matter need not be explained here as it has already been discussed at sufficient length4 ,but the fact may be conveniently represented to the eye by a symbol like the following3 ----,c---- ,the other property referred to is this3 carbon--unlike most other elements--has a peculiar capacity by virtue of which atoms of it may join together in either short or long chains1 and afterwards may gather other elements to the various parts of the chain4 ,one among the many ways in which carbon takes part in forming such compounds may be represented by the simple diagram shown in the margin3 ----,c---- ----,c---- ----,c---- ----,c---- ----,c---- ,the number of compounds of this character already known to chemists is very large2 it suggests the probability that there is no distinct limit to the number of atoms that may be linked in a continuous chain in this way4 ,moreover a given chain may have attached upon its sides or ends one or more additional chains of elements or compounds and thus give rise to an all but infinite number of substances with almost infinitely varied properties4 ,,reading ,,references4 ,coal1 and the ,coal-mines of ,pennsylvania4 ,harper's ,magazine4 xv1 #dea4 ,diamonds4 ,scribner's ,monthly4 v1 #ebi4 ,harper's ,magazine4 xix1 #dff2 xxxii1 #cdc4 ,diamond ,fields of ,south ,africa4 ,harper's ,magazine4 xlvi1 #cba4 ,,chapter ,,xxiv4 ,,compounds ,,of ,,carbon ,,and ,,oxygen4 ,while compounds of carbon and hydrogen are very numerous1 those already known being numbered by hundreds1 the affinities of oxygen and carbon give rise to a strikingly different result4 ,when combined with oxygen alone1 carbon forms but two compounds4 ,these are expressed by the following names and formulas3 ,carbon monoxide1 ,,co4 ,carbon dioxide1 ,,co4 ,carbon ,monoxide 7,,co74 ,this gas is most familiarly known as that one which often plays upon the surface of a hard coal fire and burns there with a dark blue1 feebly luminous1 flame4 ,most of the phenomena of its production and final burning may be presented as follows3 ,when an ordinary coal fire1 burning in a stove1 is amply supplied with air at the bottom1 the oxygen of the air burns the lower portions of carbon into carbon dioxide4 ,next1 this carbon dioxide is carried up1 by the draft1 between any masses of fresh coal that may be upon the top of the fire4 ,this fresh coal has itself affinity for oxygen under the circumstances just described as prevailing4 ,as a result1 each molecule of carbon dioxide from the lower portion of the fire yields one of its atoms of oxygen to an atom of carbon in the upper part4 ,the chemical change is represented by the following equation3 ,,co ,c #b;,,co4 ,one molecule of ,one atom of ,two molecules of ,carbon dioxide1 ,carbon1 ,carbon monoxide1 #dd #ab #ef parts by weight4 parts by weight4 parts by weight4 _/ _/ #ef #ef ,as a result1 therefore1 carbon monoxide is formed and escapes as a colorless gas from the top of the fuel2 there1 if the upper door of the stove admits a sufficient amount of air1 the carbon monoxide combines with the oxygen of this air1 and burns with the blue flame already referred to1 and so produces carbon dioxide again4 ,this chemical change is represented by the following equation3 #b;,,co ,o #b;,,co ,two molecules of ,one molecule of ,two molecules of ,carbon monoxide1 ,oxygen1 ,carbon dioxide1 #ef #cb #hh parts by weight4 parts by weight4 parts by weight4 _/ _/ #hh #hh ,the carbon monoxide is a very poisonous gas1 far more injurious to health than carbon dioxide4 ,carbon ,dioxide 7,,co74 ,this substance and its manner of production have been referred to more than once in preceding chapters4 ,a more extended notice of it1 however1 is appropriate to this place4 ,it has already been stated that carbon dioxide exists ready-formed in nature--notably in the atmospheric air4 ,its principal natural source in the atmosphere is the combustion of fuel2 for almost all fuel is carbonaceous4 ,thus coal1 wood1 oil1 illuminating gases1 are all highly carbonaceous substances1 and one of the principal products of their combustion is the gas now under consideration4 ,illustration3 ,,fig4 #ij4--,machinery for filling bottles with artificial mineral waters4 ,as has already been described1 the respiration of animals is closely connected with a real combustion in the living being4 ,it is true that this sort of combustion is not attended by the evolution of light2 it is productive of heat1 nevertheless1 and the heat afforded by respiration is an important factor in the sustenance of animal existence4 ,for this heat not only enables the living being to endure the chilling effects of the winter's cold2 it also keeps the temperature of the internal organs up to that point which is necessary for the proper performance of certain animal functions--of which digestion is a most important example4 ,now by this combustion carbon dioxide is generated just as truly as would be the case if the flesh of the living animal were consumed in a glowing fire4 ,the product of respiratory combustion is the same carbon dioxide as that recognized in well-established burnings4 ,the quantities of carbon dioxide evolved by man and certain of the domestic animals1 in each hour of their existence1 have been calculated4 ,they are approximately stated in the following table3 ,a man exhales #d gallons carbon dioxide per hour4 ,a dog 0 #d 0 0 0 0 0 ,a horse 0 #ej 0 0 0 0 0 ,an ox 0 #gj 0 0 0 0 0 ,illustration3 ,,fig4 #hi4--,production of carbon dioxide by combustion of a diamond in oxygen gas4 ,and ,m4 ,boussingault has calculated that the approximate amount of carbon dioxide produced in the city of ,paris during a single twenty-four hours is as follows3 ,amount produced by living animals1 #ee1jjj1jjj cubic feet4 ,amount produced by burning of various kinds of fuel1 #bg1jjj1jjj cubic feet4 -------------------- ,total ,,co produced in twenty-four hours1 #hb1jjj1jjj cubic feet4 ,there are certain other natural sources of carbon dioxide that are worthy of passing mention4 ,thus in many parts of the world the gas is continually evolved not only from active volcanoes but also from extinct ones4 ,again1 another interesting source--though not in the aggregate a very important one--is found in natural mineral springs4 ,in these the water often comes to the surface highly charged with carbon dioxide1 and the gas1 escaping into the air1 imparts to the water its well-known bubbling appearance4 ,experiments with ,carbon ,dioxide4 ,for chemical purposes carbon dioxide is commonly produced by the action of an acid upon some one of the salts known as carbonates4 ,accordingly chlorohydric acid and calcic carbonate 7that is1 common marble7 when brought together produce carbon dioxide4 ,this fact may be readily shown by the performance of a simple but interesting experiment4 ,the operation may also serve for the display of some of the principal properties of the gas4 ,the experiment in question may be conducted advantageously somewhat as follows3 ,provide two convenient glass jars--such as candy jars or preserve jars2 also a short candle1 a piece of copper wire1 a bottle of chlorohydric acid and some fragments of white marble4 ,now attach the candle to the wire and after lighting the former let it down into the jars1 still burning4 ,the combustion continues because the jars are full of air and contain ample quantities of oxygen4 ,next withdraw the candle and extinguish it for a moment4 ,now place in the bottom of the larger jar some chlorohydric acid and into it gently drop some of the fragments of marble4 ,effervescence immediately commences4 ,a careful examination of effervescence shows that in this1 as in other cases1 the process consists in the evolution of a gas from a liquid4 ,in the case in question a colorless gas is plainly evolved1 and this gas is carbon dioxide4 ,the chemical change is represented by the following equation3 ,ca,c,o #b;,h,cl ,one molecule of ,two molecules of ,calcic carbonate1 ,chlorohydric acid1 #ajj #gc parts by weight4 parts by weight4 _/ #agc ,,co ,ca,cl ,h,o ,one molecule of ,one molecule of ,one molecule of ,carbon dioxide1 ,calcic chloride1 ,water1 #dd #aaa #ah parts by weight4 parts by weight4 parts by weight4 _/ #agc ,after allowing the effervescence to continue for five or ten minutes1 relight the candle and again lower it into the jar now containing carbon dioxide4 ,if a sufficient quantity of the gas is present1 the light will be promptly extinguished when the wick passes below the surface of the gas4 ,the experiment displays at this stage the additional fact that the carbon dioxide is heavy1 and in filling the jar it does so from the bottom upward4 ,now relight the candle and immerse it in the second jar2 this is proved to contain air by the fact that the candle continues to burn4 ,while it is still quietly burning there1 pour gently upon it the carbon dioxide accumulated in the other jar4 ,if the amount of this gas is large enough1 it will fill the jar containing the lighted candle and so will readily extinguish the latter4 ,these experiments demonstrate simply and clearly1 certain of the most important properties of carbon dioxide4 ,its action in extinguishing flame is to quench it1 very much as water would4 ,when the candle dips beneath the surface of the carbon dioxide1 the flame expires simply from lack of that oxygen of the air which ordinarily supports the combustion4 ,and this leads very naturally to the additional statement that1 in similar fashion1 living beings are drowned if immersed in carbon dioxide4 ,for just as water prevents the access of air to the lungs1 and then drowning ensues1 so when the animal is beneath the surface of carbon dioxide he dies from the similar deprivation of air4 ,effervescing ,beverages4 ,a large quantity of carbon dioxide taken into the lungs is promptly fatal to animal life1 and even a small increase of that gas1 in the atmospheric air breathed1 also produces a marked lowering of the vitality4 ,it is an interesting fact however that when this gas is taken into the stomach1 especially in its solution in water1 it has a wholesome and stimulating effect4 ,when carbon dioxide is dissolved in water it seems to produce a true acid1 though an unstable one4 ,in accordance with the present nomenclature1 this acid is called carbonic acid and is represented by the formula ,h,,co4 ,this substance is present as the main constituent1 or as a subordinate one1 in certain natural mineral waters1 and in many simple effervescent beverages4 ,thus plain soda-water is merely a solution of carbon dioxide in water4 ,such solutions are now manufactured on a large scale1 and by mechanical appliances are filled into siphonlike bottles in such a way that small quantities of the liquid may be withdrawn without loss of the principal stock of gas4 ,,chapter ,,xxv4 ,,illuminating ,,gas4 ,it has been stated more than once that the compounds of carbon are very numerous2 it might properly be added that their usefulness is no less striking than their number4 ,this portion of the subject is so vast1 however1 that it is often discussed as an entirely separate branch1 called the chemistry of the carbon compounds1 and often organic chemistry4 ,by organic chemistry is meant the chemistry of organic substances2 and by organic substances is meant materials derived from those existences that possess organs4 ,now animals and plants1 and they alone1 possess organs2 whence organic chemistry is described as the chemistry of animal and vegetable bodies4 ,on some accounts1 it is better defined as the chemistry of the carbon compounds2 for while it was formerly thought that animal and vegetable beings involved in their processes a chemistry peculiar to themselves1 this notion has long since been dispelled1 and it is now clearly perceived that animal and vegetable compounds are governed by the same chemical laws as others4 ,but not only is the number of these organic compounds very great2 the variety and importance of animal and vegetable matters give them a high degree of interest4 ,thus they include animal and vegetable juices1 extracts1 gums1 resins1 essences1 remedial agents1 bitter principles1 acids1 oils1 coloring matters2 and of the members of each one of these classes the name is legion4 ,moreover1 the more any portion of the subject is studied1 the more it seems to reveal a continually increasing complexity4 ,most of the substances of the classes referred to are either compounds of carbon and hydrogen1 or of carbon1 hydrogen and oxygen in varied proportions1 or they are compounds containing these elements and yet a few others combined with them4 ,it is manifest1 from what has been said1 that in a book like the present it is impossible to give any considerable discussion of the vast field offered by the organic compounds of carbon4 ,it seems better to choose for description some important manufacturing operation that involves these compounds and that is on other accounts specially instructive4 ,accordingly the manufacture of illuminating gas is selected for consideration here4 ,the ,manufacture of ,illuminating ,gas4 ,the material on which this industry is based is bituminous coal4 ,this substance is clearly a vegetable product1 though it is derived from a vegetation which lived1 flourished and decayed in a period of prehistoric antiquity4 ,the manufacture of illuminating gas1 although one of the most important of the chemical industries of to-day1 had its beginning but little before the opening of the present century4 ,a ,scotchman named ,william ,murdoch is generally credited with the first introduction1 into considerable use1 of burning gas made from coal4 ,in #agih he gained the opportunity to introduce his method of illumination into the engine works of ,boulton ,watt1 located at ,soho1 near ,birmingham4 ,from that date the manufacture and use of illuminating gas from soft coal has extended and expanded until it has reached its present enormous development4 ,general ,principles of the ,process4 ,the general principle of the manufacture is exceedingly simple4 ,but its commercial growth has been assisted by the invention and application of a multitude of delicate and ingenious appliances4 ,if any person will take a glass test-tube1 place in it a few fragments of starch1 and will then heat the starch strongly over a lamp flame1 he will readily detect three important effects4 ,the first is that a mass of smoky gas or vapor pours out of the mouth of the test-tube4 ,the second is that an oily or tarry liquid condenses1 on the inside of the tube1 and runs down in streams4 ,the third is that at the close of the operation a mass of carbon remains in the bottom of the tube where the starch was4 ,now the various substances1 that have been referred to as produced by the heating process1 are referable to the decomposition of the molecules of starch4 ,a ,similar ,operation on a ,large ,scale4 ,in the manufacture of illuminating gas on a large scale there are developed practically the same series of phenomena as those noted in the experiment with starch just referred to4 ,illustration3 ,,fig4 #ib4--,three views of a gas retort4 ,in the manufacture of illuminating gas1 instead of starch as just described1 soft coal or bituminous coal is used4 ,in place of a lamp1 a large row of furnaces is employed to supply the heat4 ,instead of glass tubes1 those of earthenware1 ten or twelve feet in length and between one and two feet in diameter1 are used4 ,these tubes1 called retorts1 are placed in a horizontal position and so that the flame of the fire in the furnace may sweep around them and raise them to a cherry-red heat4 ,at the front end of the retort is attached a door to prevent the escape of the gases generated1 and there is also a suitable pipe to carry these gases forward to those other portions of the works which serve to perform upon the crude gas certain necessary purifications2 these are3 ,first4 ,the condensation of condensable vapors4 ,second4 ,the removal of objectionable gases4 ,illustration3 ,,fig4 #ic4--,section showing five retorts in place4 ,the operations spoken of show that the gas must be carried from one portion of the establishment to another4 ,now illuminating gas is made up of material substances and although lighter than air yet they distinctly possess weight4 ,gas will not move of itself2 to carry it from place to place the application of force by means of mechanical appliances is requisite4 ,in fact it is discovered that what is called an exhauster is necessary for use in gas-works4 ,the exhauster is simply a kind of rotary pump which pulls the gas from the retorts in which it is first formed1 and pushes it along through the various purifiers1 to the gas holder in which it is stored4 ,if the exhauster were not used1 there would be a constant tendency to the creation of pressure in the retort1 by virtue of which the gas would penetrate the earthenware into the fire1 and so become a source of loss4 ,from what has been said it will be easily comprehended that the essential parts of a gas-works are the following3 ,first4 ,the furnace4 ,second4 ,the retorts1 in which the coal is heated4 ,third4 ,the hydraulic main3 a trough of water in which the gas is cooled1 and which also serves as a gate1 through which the gas can pass forward toward the purifiers but not backward toward the retort4 ,fourth4 ,the out-door condensers1 in which the gas is cooled and some of its vapors condense to tarry liquids4 ,fifth4 ,the scrubber1 in which the gas is cleansed by a spray of water4 ,illustration3 ,,fig4 #ia4--,view in gas-works2 drawing coke from the retorts4 ,illustration3 ,,fig4 #id4--,section to show the processes of the manufacture of illuminating gas4 ,sixth4 ,the purifiers1 where sulphuretted hydrogen1 and some other objectionable gases are removed4 ,seventh4 ,the gas holder1 in which the finished gas is collected and stored prior to delivery to consumers4 ,the processes by which these various appliances are used in the manufacture of illuminating gas may be briefly sketched as follows3 ,a suitable quantity of soft coal is placed in an even layer on the bottom of the retort4 ,gas at once forms and streams out of the open door4 ,the door of the retort being now quickly closed by the workmen1 the gas passes out through an exit pipe--called the dip-pipe because it dips into the water of the hydraulic main4 ,the gas bubbles up from the dip-pipe through the water4 ,once delivered in the hydraulic main1 the gas cannot go back to the retort4 ,next1 the gas passes through the condensers1 a series of connected up-and-down pipes4 ,as these condensers stand in the open air they cool the gas so that it deposits tarry liquids that1 until this stage1 have been suspended in it in the form of vapor4 ,next the gas flows to a large iron box1 called the scrubber4 ,in different works the scrubber varies considerably in outward shape and internal arrangements4 ,its essential office however is to wash the gas1 and it does so by the use of water which is applied to the gas either in sprays or thin films4 ,ammonia gas is the principal substance absorbed by the water in the scrubber4 ,indeed the liquor thus produced is the main commercial source1 at the present day1 of ammonia and its compounds4 ,the gas next goes to the purifiers4 ,these are large iron boxes supplied with a multitude of shelves upon which1 in most works1 dry quicklime is spread4 ,the quicklime absorbs sulphuretted hydrogen and some other acid gases4 ,from these purifiers the gas is carried on to the gas holder4 ,the ,distillation of ,coal1 ,chemically ,considered4 ,under the influence of the high temperature of the gas furnace1 the soft coal in the retorts undergoes decomposition4 ,as has before been intimated1 three distinct classes of substances are produced3 ,solids1 which are left in the retorts2 liquids1 which are condensed in the various coolers2 gases1 which pass on the gas holder4 ,first4 ,the solids4 ,these are principally two kinds of carbon4 ,one is coke1--the principal solid matter found in the retorts as a residue from the soft coal after the latter has ceased to evolve gas4 ,it is merely a form of carbon1 somewhat spongy in its structure4 ,it is sold for use as fuel4 ,beside this the retorts accumulate a sort of scale of a very different form of carbon called gas carbon4 ,it is extremely hard and almost non-combustible1 being even very difficult to remove from the retorts4 ,it is at present somewhat used in the manufacture of the carbon pencils employed in electric lights of the arc variety4 ,prior to this use it found scarcely any commercial outlet4 ,second4 ,the liquids4 ,the first condensation of liquids takes place in the hydraulic main where tarry and oily matters condense and accumulate1 and are drawn off from time to time into the tar well4 ,again in the condensers there is a still further deposition of liquids1 also tarry and oily in their nature4 ,these liquids consist of very complicated mixtures of carbon compounds1 but they are of the most interesting character4 ,in the earlier stages of the manufacture of coal-gas they were regarded as mere nuisances4 ,little by little however chemists have learned to separate the intermingled products1 and have thus been able to obtain a number of substances of striking interest and usefulness in the arts4 ,among the multitudes of substances that go to make up the liquid called coal-tar1 some are as yet hardly classified others are distinctly recognized and have uses of great commercial importance4 ,of these latter1 two will be mentioned here4 ,these are anthracene and benzole4 ,the substance called anthracene1 a compound of carbon and hydrogen 7,c,h71 has within the last ten years sprung into the highest commercial importance4 ,this is referable to the fact that it has been found to be a suitable material from which1 by chemical processes1 there may be manufactured a substance known as alizarine1 besides other equally valuable and interesting compounds4 ,alizarine was previously recognized as the coloring matter of chief value in madder root1 a substance that has been used as a dye-stuff for above a thousand years4 ,the alizarine1 whether of madder or from anthracene1 is a coloring matter of the highest value and usefulness4 ,it affords turkey-red and other colors that are very important because they are extremely brilliant and extremely fast4 ,its artificial manufacture1 from the anthracene of the filthy and offensive coal-tar1 is one of the greatest triumphs of this or any age4 ,another substance found in the coal-tar is benzole1 a compound of carbon and hydrogen having the formula ,c,h4 ,this is the principal material from which1 by a variety of well understood though complicated chemical processes1 the well-known aniline colors have been produced4 ,while these colors may well command the admiration of all1 on account of their unsurpassed beauty and brilliancy1 they are of especial interest to the scientist by reason of the chemical laws they illustrate4 ,the preparation of these colors1 as a group1 ranks second only as a chemical achievement to that of artificial alizarine4 ,third4 ,the ,gaseous ,products4 ,the gases generated in the process of the coal-gas manufacture are extremely numerous2 some of them are of high illuminating power1 of which that called ethylene 7,c,h7 is an excellent example4 ,again there are some that are combustible1 but yet are of slight illuminating power4 ,substances of this class are present in the finished product4 ,hydrogen and carbon monoxide 7,,co7 may serve as examples4 ,there are always present also gases that are either injurious to the illuminating power or are otherwise objectionable4 ,for example1 nitrogen is always present1 and it is not practicable to remove it from the gas4 ,it contributes nothing to the value of the product4 ,again certain sulphur compounds1 like sulphuretted hydrogen1 are usually present4 ,these indeed burn1 but they give rise to offensive and unwholesome oxides of sulphur4 ,the sketch thus given1 while it but imperfectly describes the wonderful industry in question1 with its various well contrived and delicate appliances1 serves however to give some idea of the importance of the operation1 from a chemical point of view1 and the mine of rich materials its carbon compounds offer to chemical students4 ,,closing ,,chapter4 ,,chapter ,,xxvi4 ,,silicon4 ,silicon may well be considered important on account of its quantity in the earth1 if on no other4 ,in an earlier chapter it has been shown that oxygen exists in our globe--including its atmosphere and its oceans--in an amount equal to about one-half of the weight of the whole4 ,now silicon exists in a quantity equal to about one-fourth of this entire weight4 ,in the earth however1 neither of these substances exists in the uncombined form4 ,these facts seem to involve as a necessary consequence that they exist in the earth1 to a large extent1 combined with each other2 indeed this is found to be the case4 ,the principal earthy matter of our planet is the compound of silicon and oxygen1 existing either alone in the form of sand1 quartz crystal and similar minerals1 or else in combination with other well-known abundant earth materials1 such as oxides of calcium1 magnesium and aluminum4 ,it has already been stated that carbon is the characteristic element of animal and vegetable matters2 so silicon is the characteristic element of mineral matters4 ,thus granite and similar archaic rocks contain approximately twenty-five per cent of silicon4 ,in nature1 silicon performs its important office as a constituent of rock material1 with a fitness that is referable largely to the high degree of stability possessed by most of its compounds4 ,the permanence of the materials of the earth's surface under the influence of heat1 and water1 and frost1 and similar agencies is an illustration of this principle4 ,silicic oxide 7,si,o71 occurs on our globe in many different forms of which diatomaceous earth and rock crystal may be mentioned4 ,diatomaceous earth is a powdery material found in abundant deposits in many parts of the world4 ,its characteristic structure1 when examined under the microscope1 reveals its nature2 then it is seen to be made up of the shells of minute vegetable organisms called diatoms4 ,these assume a great many beautiful forms1 and some of them are checkered all over with markings of such extreme fineness that they have been used as test objects for trying the resolving power of the objectives of microscopes4 ,this kind of earth is employed1 as has already been stated1 in the preparation of dynamite4 ,illustration3 ,,fig4 #ie4--;,diatomaceous earth as seen through the microscope4 ,quartz sometimes occurs in colorless transparent masses of great beauty and clearness called rock crystal4 ,the amethyst is the same substance slightly colored by compounds of the metal manganese1 while quartz exists of a variety of other shades1 in some of which it is prized as a gem4 ,quartz generally assumes forms of a hexagonal tendency3 they are often hexagonal prisms terminated by hexagonal pyramids4 ,illustration3 ,,fig4 #if4--,mass of natural quartz crystals4 ,quartz and the finer and purer varieties of sand are used largely in the manufacture of glass4 ,the silicic oxide here displays what may be expressed as its acid tendencies2 for in the manufacture of glass it is fused with sodic carbonate1 and then the silicic oxide displaces the carbon dioxide from the sodic carbonate2 as a result there is formed what must be regarded as a true salt1 or a mixture of salts1 that in the simplest kind of glass may be termed sodic silicate4 99 99 99 99 99 ,closing ,words4 ,the course laid out in the preface is now terminated with silicon1 as there planned4 ,from scientific considerations1 this is a natural ending2 it seems to be appropriate on another account also4 ,after the reader has been carried1 in thought1 among the various gaseous elements1 that make up atmosphere and oceans1 it seems suitable that we should say farewell to him upon the discussion of that element that may be called the characteristic material of our solid earth4 ,,index4 ,abel1 ,f4 ,a41 #ahb ,acid1 ,boric1 #aeg ------ ,nitric1 #ce1 #afh ------ ,sulphuric1 #ce1 #cg1 #aeb ------ ,chlorohydric1 #cc1 #aij ------ ,phosphoric1 #aib ,affinity1 ,chemical1 #dd1 #df-eb ,alizarine1 #bbf ,alkali ,trade1 #id1 #ajf ,allotropism1 #aij ,amethyst1 #bbi ,ammonia1 #aff1 #agd1 #bbe ,anhydride1 #aea ,anhydrite1 #adf ,anthracene1 #bbf ,antimony1 ,sulphide of1 #adh ,apatite1 #ahh1 #ahi ,arsenic1 ,sulphide of1 #adh ,atom1 #da1 #db ,atomic ,theory1 #eb ,atmosphere1 #agj ,bacon1 ,roger1 #agh ,balard1 #ajj ,balloons1 #gd ,barilla1 #ajg ,benzole1 #bbg ,berthollet1 #id ,berzelius1 #bd ,beverages1 effervescing1 #bai ,binary ,compounds1 #cb ,biot1 #hj ,black1 ,joseph1 #fa1 #fc1 #gf ,bleaching-,powder1 #ic ,blende1 #adf ,blowpipe1 ,compound1 #abi ,bone-,ash1 #ahg ,borax1 #aeg ,boron1 #aeg ,boussingault1 #bag ,brandt1 #ahg ,bromine1 #ajj ,carbon1 #aig ------ ,dioxide1 #agc1 #baf ------ ,monoxide1 #bae ,cavendish1 ,henry1 #fj ,charcoal1 #aig ,chemistry1 ,scope of1 #g1 #i ,chlorine1 #he ,cinnabar1 #adf ,coal1 #bja ,coal-tar1 #bbf ,coke1 #bbf ,compounds1 #cb ------ ,number of1 #h1 #i ------ ,organic1 #bba ,copper1 ,sulphate of1 #ea ,cotton1 #aha ,courtois1 #ajh ,current1 ,galvanic1 #fd ,daguerre1 #ajc ,dalton1 ,john1 #eb1 #ef ,davy1 ,humphry1 #fj1 #hf1 #ajh ,de ,rozier1 #gh ,diamond1 #bjc ,diatoms1 #ahe1 #bbh ,diffusion1 #fi ,dbereiner1 #gj ,dynamite1 #ahc1 #ahe ,earth's ,crust1 ,composition of1 #ae ,elements1 ,chemical1 #i1 #ab1 #ad1 #bh ------ ,names and ,symbols of1 #ai1 #bc ,equivalence1 #dh1 #gb ,ethylene1 #bbg ,explosives1 #agg ,fertilizers1 #ahh ,fluorine1 #aab ,fireworks1 #ahj ,fulminates1 #aha ,galena1 #adf ,gas1 #fc ---- ,illuminating1 #bba ,gas-,carbon1 #bbf ,gay-,lussac1 #hj ,glaisher and ,coxwell1 #ha ,glass1 #bbi ,glycerine1 #ahd ,granite1 #bbh ,graphite1 #bja ,gun-,cotton1 #aha ,gunpowder1 #agg ,hay1 #ae ,heat1 unit of1 #ga ,hydrogen1 #eh ,iodine1 #aje ,iron1 ,sulphide of1 #adf ,janssen1 #hc ,kelp1 #ajg ,lamp-,black1 #bjj ,larderel1 #afj ,lavoisier1 #ai1 #ba1 #aah ,lead1 #cd ------ ,sulphide of1 #adf1 #adh ,leblanc ,process1 #id ,liebig1 #aja ,light1 ,calcium1 #aca ------ ,electric1 #baa1 #bbf ,limestone1 #bji ,lithium1 #cj ,marble1 #bji ,mass1 #ci ,matches1 #aib ,mayow1 #aba1 #afc ,metals1 #bh1 #bi ------ ,names of1 #af1 #bj ,mercury1 #cj ------ ,sulphide of1 #adf ,moisture in the ,air1 #agc ,molecule1 #dj ,montgolfier1 #gd ,murdoch1 #bbb ,nobel1 #ahe ,nitrogen1 #afb ,nitroglycerine1 #ahd ,nomenclature1 ,chemical1 #ai1 #bj1 #cb1 #cc1 #cg ,non-metal1 #cj ,oxide1 ,ferroso-ferric1 #ff ,oxygen1 #aag ------ ,abundance of in the earth1 #ad1 #af ,palladium1 #gj ,pelletier1 #hi ,petroleum1 #bji ,photography1 #ic ,phosphorus1 #ahg ,phosphorus ,necrosis1 #ahi ,phosphuretted ,hydrogen1 #aia ,potassic ,chlorate1 #abc ,priestley1 ,joseph1 #fd1 #aah1 #afc ,puymaurin1 #aae ,pyrites1 #adf ,quartz1 #bbh ,roe1 #hi ,references1 ,reading1 #aj1 #ag1 #bd1 #bg1 #ca1 #ch1 #de1 #ef1 #gc1 #hd1 #ih1 #aaa1 #aaf1 #acc1 #aef1 #afa1 #ahf1 #aif1 #bad ,rutherford1 #afc ,scheele1 #he1 #aad1 #aah1 #afb1 #ahg ,silicon1 #bbh ------ ,abundance of1 #af ,sodium1 #fg ,sugar1 #da ,sulphur1 #adb ------ ,dioxide1 #cc1 #adi ------ ,trioxide1 #cc1 #aea ,sulphuretted ,hydrogen1 #adg ,ternary ,compounds1 #cd ,van ,helmont1 #fc ,varech1 #ajg ,vitriol1 ,oil of1 #aeb ,water1 #abg1 #acd ,weight1 ,atomic1 #ag ,zinc1 #fh ---- ,sulphide of1 #adf1 #adi