,transcrib]'s ,note3 ,boldface text is indicat$ by b>s & ,italic text by und]scores4 ,subscripts are %[n z normal numb]s3 ,h#b,o4 ,a ,,hi/ory ,,( ,,! ,,sci5ces ,a/ronomy1 by ,pr(4 ,,george ,,=bes1 ,f4,r4,s4 ,*emi/ry1 #b volumes1 by ,sir ,,edw>d ,,?orpe1 ,c4,b41 ,d ,sc41 ,f4,r4,s41 etc4 7,director ( ,gov]nm5t ,laboratories7 ,old ,te/am5t ,criticism1 by ,pr(4 ,,ar*ibald ,,duff 7,pr(4 ( ,hebrew & ,old ,te/am5t ,!ology 9 ! ,unit$ ,college1 ,brad=d7 ,9 ,active ,prep>ation-- ,new ,te/am5t ,criticism1 by ,f4 ,c4 ,,conybe>e1 ,m4,a4 7,late ,fell[ & ,prlector ( ,univ4 ,coll41 ,ox=d7 ,geology1 by ,h4 ,b4 ,,woodw>d1 ,f4,r4,s41 ,f4,g4,s4 7,assi/ant ,director ( ,geological ,survey7 ,geography1 by ,dr4 ,,scott ,,keltie1 ,f4,r4,g4,s41 ,f4,s4,a4 ,g4 ,p4 ,,putnam',s ,,sons ,new ,york ,london ,illu/ration3 ,,ju/us ,,von ,,liebig ,a ,,hi/ory ,,( ,,! ,,sci5ces ,,hi/ory ,,( ,,*emi/ry ,,by ,,sir ,,edw>d ,,?orpe ,c4,b41 ,,ll4,d41 ,f4,r4,s4 ,,au?or ,,( 8,,essays ,,9 ,,hi/orical ,,*emi/ry10 8,,humphry ,,davy3 ,,poet ,,& ,,philosoph]10 8,,joseph ,,prie/ley10 ,,etc41 ,,etc4 ,,two ,,volumes ,,ii4 ,f #ahej to #aiaj ,,) ,,illu/rations ,g4 ,p4 ,,putnam',s ,,sons ,,new ,,york ,,& ,,london ,! ,knick]bock] ,press #aiaj ,,copyright1 #aiaj ,,by ,g4 ,p4 ,,putnam',s ,,sons ,?is s]ies is publi%$ 9 ,london by ,,! ,,rationali/ ,,press ,,association1 ,,limit$ ,! ,knick]bock] ,press1 ,new ,york ,,publi%]s' ,,note ,a ,hi/ory ( ! ,sci5ces has be5 plann$ to pres5t = ! in=mation ( ! g5]al public a hi/oric record ( ! great divisions ( sci5ce4 ,ea* volume is ! "w ( a writ] :o is accept$ z an au?ority on 8 own subject-matt]4 ,! books are n to be consid]$ z prim]s1 b pres5t ?or\ghly dige/$ in=mation on ! relations borne by ea* great division ( sci5ce to ! *anges 9 human ideas & to ! intellectual developm5t ( mank9d4 ,! monographs expla9 h[ ! pr9cipal sci5tific discov]ies h be5 arriv$ at & ! names ( ! work]s to :om su* discov]ies are due4 ,! books w comprise ea* ab\t #bjj pages4 ,ea* volume w conta9 f #ab to #af illu/rations1 includ+ portraits ( ! discov]]s & explanatory views & diagrams4 ,ea* volume conta9s also a concise b compreh5sive bibliography ( ! subject-matt]4 ,! foll[+ volumes w be issu$ dur+ ! c\rse ( ! autumn ( #aiji4 ,! ,hi/ory ( ,a/ronomy4 ,by ,,george ,,=bes1 ,m4,a41 ,f4,r4,s41 ,m4 ,in/4 ,c4,e42 au?or ( ,! ,transit ( ,v5us1 etc4 ,! ,hi/ory ( ,*emi/ry3 ,vol4 ,i4 circa #bjjj ,b4,c4 to #ahej ,a4,d4 ,vol4 ,,ii4 #ahej ,a4,d4 to date4 ,by ,,sir ,,edw>d ,,?orpe1 ,c4,b41 ,,ll4,d41 ,f4,r4,s41 ,director ( ! ,gov]nm5t ,laboratories1 ,london2 ,pr(essor-elect & ,director ( ! ,*emical ,laboratories ( ! ,imp]ial ,college ( ,sci5ce & ,te*nology2 au?or ( ,a ,diction>y ( ,appli$ ,*emi/ry4 ,to be foll[$ by3 ,! ,hi/ory ( ,geography4 ,by ,dr4 ,,john ,,scott ,,keltie1 ,f4,r4,g4,s41 ,f4,s4,s41 ,f4,s4,a41 ,hon4 ,mem4 ,geographical ,societies ( ,p>is1 ,b]l91 ,rome1 ,brussels1 ,am/]dam1 ,g5eva1 etc42 au?or ( ,report on ,geographical ,education1 ,appli$ ,geography4 ,! ,hi/ory ( ,geology4 ,by ,,horace ,b4 ,,woodw>d1 ,f4,r4,s41 ,f4,g4,s41 ,assi/ant ,director ( ,geological ,survey ( ,engl& & ,wales2 au?or ( ,! ,geology ( ,engl& & ,wales1 etc4 ,! ,hi/ory ( ,an?ropology4 ,by ,a4 ,c4 ,,haddon1 ,m4,a41 ,sc4,d41 ,f4,r4,s41 ,lectur] 9 ,e?nology1 ,cambridge & ,london2 au?or ( ,/udy ( ,man1 ,magic & ,feti%ism1 etc4 ,! ,hi/ory ( ,old ,te/am5t ,criticism4 ,by ,,ar*ibald ,,duff1 ,pr(essor ( ,hebrew & ,old ,te/am5t ,!ology 9 ! ,unit$ ,college1 ,brad=d2 au?or ( ,!ology & ,e?ics ( ! ,hebrews1 ,mod]n ,old ,te/am5t ,!ology1 etc4 ,! ,hi/ory ( ,new ,te/am5t ,criticism4 ,by ,f4 ,c4 ,,conybe>e1 ,m4,a41 late ,fell[ & ,praelector ( ,univ4 ,coll41 ,ox=d2 ,fell[ ( ! ,briti% ,academy2 ,doctor ( ,!ology1 honoris causa1 ( ,giess52 ,(fic] d',academie2 au?or ( ,old ,arm5ian ,texts ( ,revelation1 etc4 ,fur!r volumes are 9 plan on ! foll[+ subjects3 ,ma!matics & ,me*anics4 ,molecul> ,physics1 ,heat1 ,life1 & ,electricity4 ,human ,physiology1 ,embryology1 & ,h]$ity4 ,ac\/ics1 ,h>monics1 & ! ,physiology ( ,he>+1 toge!r ) ,optics ,*romatics1 & ,physiology ( ,see+4 ,psy*ology1 ,analytic1 ,comp>ative1 & ,exp]im5tal4 ,sociology & ,economics4 ,e?ics4 ,comp>ative ,philology4 ,criticism1 ,hi/orical ,rese>*1 & ,leg5ds4 ,comp>ative ,my?ology & ! ,sci5ce ( ,religions4 ,! ,criticism ( ,ecclesia/ical ,in/itutions4 ,culture1 ,moral & ,intellectual1 z ,reflect$ 9 ,imag9ative ,lit]ature & 9 ! ,f9e ,arts4 ,logic4 ,philosophy4 ,education4 ,,cont5ts ,,*apt] ,i ,,page ,,/ate ,,( ,,*emi/ry ,,9 ,,! ,,middle ,,( ,,! ,,n9ete5? ,,c5tury #a ,introductory4 ,"s ,f\nd]s ( ,mod]n ,*emi/ry3 ,liebig1 ,whl]1 ,dumas4 ,rapid ,ext5sion ( ,organic ,*emi/ry aft] #ahej3 ,laur5t & ,g]h>dt1 ,h(mann4 ,developm5t ( !ory 9 ,organic ,*emi/ry4 ,o!r repres5tative m5 ( ! middle p]iod ( ! ,n9ete5? ,c5tury3 ,graham1 ,williamson1 ,buns54 ,mod]n ,*emi/ry 9 relation to ! ,atomic ,!ory4 ,,*apt] ,,ii ,,! ,,*emical ,,elem5ts ,,discov]$ ,,s9ce #ahej #bf ,nom5clature & ,classification ( ,elem5ts4 ,num]ical relation%ips4 ,modes ( discov]y4 ,! ,spectroscope4 ,csium1 rubidium1 ?allium1 indium1 gallium1 sc&ium1 g]manium4 ,! r>e e>? elem5ts4 ,indu/rial applications ( r>e elem5ts4 ,,*apt] ,,iii ,,! ,,inactive ,,elem5ts3 ,,radium ,,& ,,radio-,,activity #dc ,argon1 helium1 krypton1 neon1 & x5on4 ,radium4 ,dis9tegration !ory ( ,ru!r=d & ,soddy4 ,act9ium & polonium4 ,! emanations4 ,,*apt] ,,iv ,,atoms ,,& ,,molecules3 ,,atomic ,,weights ,,& ,,equival5ts #fa ,hypo!sis ( ,avogadro4 ,/anislao ,cannizz>o4 ,det]m9ation ( molecul> weights4 ,applicability ( law ( ,dulong & ,petit4 ,relations ( molecul> weight to osmotic pressures4 ,det]m9ation ( atomic weights4 ,hypo!sis ( ,pr\t1 ,dumas1 ,/as1 ,"l ,rayleigh1 ,l$uc1 ,morley1 ,guye1 ,!odore ,ri*>ds4 ,validity ( law ( cons]vation ( mass3 ,l&olt4 ,,*apt] ,v ,,! ,,molecul> ,,!ory ,,( ,,gases #gi ,int]dep5d5ce ( ! gase\s laws4 ,k9etic !ory ( gases3 ,b]n\lli1 ,wat]/on1 ,clausius1 ,maxwell1 ,boltzmann1 ,s*midt1 ,graham4 ,gase\s diffusion4 ,van d] ,waals's equation4 ,ratio ( specific heats3 ,kundt & ,w>burg4 ,liquefaction ( gases4 ,critical temp]atures & pressures3 ,&rews1 ,pictet & ,cailletet1 ,wroblewski1 ,olszewki1 ,dew>1 ,kamm]l+h ,onnes4 ,liquefaction ( air on ! l>ge scale4 ,rese>* at l[ temp]atures4 ,,*apt] ,,vi ,,! ,,p]iodic ,,law #aja ,pr\t1 ,?omson1 ,db]e9]1 ,newl&s1 ,de ,*anc\rtois4 ,/atem5t ( ! ,p]iodic ,law by ,m5deleff & ,lo?> ,mey]4 ,its importance z a sy/em ( classification4 ,,*apt] ,,vii ,,val5cy #aab ,orig9 ( conception ( ,val5cy3 ,williamson1 ,g]h>dt1 ,frankl&1 ,c\p]1 ,kekul4 ,tetraval5cy ( c>bon & l9kage ( atoms4 ,rational & con/itutional =mul4 ,dynamical !ories ( val5cy4 ,,*apt] ,,viii ,,! ,,*emi/ry ,,( ,,aromatic ,,comp\nds #aai ,peculi>ities ( aromatic comp\nds4 ,kekul's b5z5e !ory4 ,its applications4 ,! ess5tial oils4 ,t]p5es4 ,camphor4 ,syn!sis ( p]fumes4 ,alkaloids4 ,,*apt] ,,ix ,,/]eo-,,isom]ism3 ,,/]eo-,,*emi/ry #ach ,opticity3 ,biot1 ,mits*]li*1 ,pa/eur1 ,wislic5us1 ,van 't ,h(f1 ,le ,bel4 ,asymmetry4 ,racemisation4 ,multirotation4 ,geometrical isom]ism4 ,geometrical inv]sion4 ,/]eo-isom]ism among nitrog51 sulphur1 sel5ium1 t91 & silicon comp\nds4 ,tautom]ism4 ,/]ic h9drance4 ,,*apt] ,x ,,organic ,,syn!sis3 ,,cond5sation3 ,,syn!sis ,,( ,,vital ,,products #aeb ,use ( specific cond5s+ reag5ts4 ,c>bon suboxide4 ,artificial prep>ation ( naturally occurr+ sub/ances4 ,syn!tic m$ic9es4 ,! ptoma9es4 ,artificial aliz>94 ,indigo4 ,! sug>s & prote9s3 ,emil ,fis*]4 ,! doctr9e ( 8vital =ce40 ,,*apt] ,,xi ,,on ,,! ,,developm5t ,,( ,,physical ,,*emi/ry ,,s9ce #ahej #aga ,molecul> volumes ( liquids4 ,nature ( solution4 ,van 't ,h(f's application ( ! gas laws to ph5om5a ( solution4 ,osmosis & osmotic pressure4 ,traube4 ,pfeff]4 ,semi-p]meable membranes4 ,measurem5t ( osmotic pressure4 ,arrh5ius4 ,doctr9e ( ionisation4 ,its applicability to ! explanation ( *emical ph5om5a4 ,!rmo-*emi/ry4 ,mass action4 ,nature ( rev]sible reactions4 ,!rmal & ,electrolytic dissociation4 ,relation betwe5 *emical nature & opticity1 magnetic rotation & viscosity4 ,!ory ( phases4 ,catalysis4 ,enzyme action4 ,relations betwe5 val5cy & volume4 ,photo*emi/ry4 ,,bibliography #ahg ,,index #aia ,,illu/rations ,,page ,,ju/us ,,von ,,liebig ,frontispiece ,,jean ,,bapti/e ,,&r ,,dumas #i ,,?omas ,,graham #ac ,f a pa9t+ by ,g4 ,f4 ,watts1 ,r4,a41 9 ! possession ( ! ,royal ,society ,,alex&] ,,william ,,williamson #ae ,,buns51 ,,kir*h(f1 ,,& ,,roscoe #ai ,,sir ,,william ,,ramsay #dh ,,m>ie ,,curie 7ne ,,sklod[ska7 #ef ,,/anislao ,,cannizz>o #fe ,,sir ,,james ,,dew> #ih ,,dmitri ,,ivan[its* ,,m5del,,eff #aaj ,,augu/ ,,kekul ,,von ,,/radonitz #abf ,,jacobus ,,h5ricus ,,van ',t ,,h(f #adb ,,emil ,,fis*] #aff ,,svante ,,augu/ ,,arrh5ius #ahj ,,hi/ory ,,( ,,*emi/ry ,,*apt] ,i ,,/ate ,,( ,,*emi/ry ,,9 ,,! ,,middle ,,( ,,! ,,n9ete5? ,,c5tury ,9 ! prec$+ volume an attempt 0 made to outl9e ! significant features 9 ! developm5t ( *emi/ry1 z an art & z a sci5ce1 f ! e>lie/ times d[n to ab\t ! middle ( ! la/ c5tury4 ,s9ce t "t *emi/ry has progress$ at a rate & to an ext5t unp>allel$ at any p]iod ( its hi/ory4 ,n only h ! numb] & v>iety ( *emical products--inorganic & organic--be5 enorm\sly increas$1 b ! /udy ( _! modes ( orig91 prop]ties1 & relations has greatly ext5d$ our means ( ga9+ an insight into ! int]nal /ructure & con/itution ( bodies4 ,?is extraord9>y developm5t has c>ri$ ! sci5ce beyond ! limits ( its own special field ( inquiry1 & has influ5c$ e dep>tm5t ( natural k4 ,concurr5tly !re has be5 a no less /rik+ ext5sion ( its applications to ! prosp]ity & mat]ial welf>e ( mank9d4 ,) ! dea? ( ,davy ! era ( brilliant discov]y 9 *emi/ry1 wrote ,edw>d ,turn]1 appe>$ = ! mom5t to h t]m9at$4 ,al?\gh ! numb] ( work]s 9 ! sci5ce /eadily increas$1 ! output ( *emical lit]ature 9 ,engl& actually dim9i%$ = "s ye>s2 &1 z reg>ds inorganic *emi/ry1 few fir/-rate discov]ies 7 made dur+ ! two decades prior to #ahej4 ,*emi/s seem$ to be ( ,turn]'s op9ion t ! "t _h arriv$ = review+ _! /ock ( in=mation1 & = submitt+ ! pr9cipal facts & fundam5tal doctr9es to ! sev]e/ scrut9y4 ,_! activity 0 employ$ n s mu* 9 se>*+ = new comp\nds or new elem5ts z 9 exam9+ ^? already discov]$4 ,! f\ndations ( ! atomic !ory 7 be+ securely laid4 ,! ratios 9 :i* ! elem5ts ( kn[n comp\nds are unit$ 7 be+ m exactly asc]ta9$4 ,! ef=ts ( work]s1 ,graham except$1 seem$ to be sp5t m on po9ts ( detail1 on ! fill+-9 ( little gaps 9 ! *emical /ructure1 z x !n exi/$1 ?an 9 attempts at new developm5ts4 ,= a "t--dur+ ! e>ly '?irties--*emi/s /ruggl$ ) ! claims ( rival me?ods ( notation1 & x 0 only gradually t ! sy/em ( ,b]zelius ga9$ g5]al acceptance4 ,at none ( ! ,briti% univ]sities 0 !re any?+ 9 ! nature ( practical tuition 9 *emi/ry4 ,?omson1 at ,glasg[1 occasionally p]mitt$ a /ud5t to "w "u him1 b no sy/ematic in/ruction 0 ev] attempt$4 ,! fir/ impulses came f ,graham 9 #ahcg1 :5 he took *>ge ( ! *emical tea*+ at ! ,univ]sity ( ,london1 & :51 9 #ahda1 he assi/$ to create ! ,*emical ,society ( ,london4 ,f\r ye>s lat] ! ,royal ,college ( ,*emi/ry 9 ,london 0 f\nd$ & plac$ "u ! direction ( ,augu/ ,wilhelm ,h(mann--"o ( ! mo/ di/+ui%$ pupils ( ,liebig4 ,"u 8 inspiration ! /udy ( practical *emi/ry made extraord9>y progress1 & discov]y succe$$ discov]y 9 rapid succession4 ,9 br++ ,h(mann to ,engl& we _h1 9 fact1 import$ some?+ ( ! _s & p[] ( 8 ma/]1 ,liebig4 ,among ! pupils & co-work]s ( ,h(mann 7 ,w>r5 de la ,rue1 ,abel1 ,ni*olson1 ,mansfield1 ,m$lock1 ,crookes1 ,*ur*1 ,griess1 ,m>tius1 ,sell1 ,div]s1 & ,p]k94 ,:il/ at ,giess5 he _h begun ! /udy ( ! organic bases 9 coal-t> ) a view m especially ( e/abli%+ ! id5tity ( ,fritzs*e's anil9 ) ! b5zidam ( ,z99 & ! kry/all9 ( ,unv]dorb54 ,h(mann cont9u$ to cultivate ) unremitt+ zeal ! field ?us ent]$4 ,) ,muspratt he discov]$ p>atoluid9e & nitranil9e2 ) ,cah\rs allyl alcohol4 ,8 pupil ,mansfield work$ out1 at ! co/ ( 8 life1 ! me?ods = ! te*nical extraction ( b5z5e & tolu5e f coal-t>1 & !reby made ! coal-t> col\r-indu/ry possible4 ,x 0 9 attempt+ to syn!sise qu99e by ! oxidation ( anil9e t ,p]k91 !n an assi/ant at ! college1 obta9$1 9 #ahef1 anil9e purple1 or mauve1 z x came to be call$ by ! ,fr5*1 ! fir/ ( ! s-call$ coal-t> col\r+ matt]s4 ,9 #ahei ?is 0 foll[$ by ! discov]y ( mag5ta1 or fu*s9e1 by ,v]qu94 ,= its manufacture ,m$lock1 "o ( ,h(mann's pupils1 9 #ahfj devis$ a process by :i* = a "t x 0 almo/ exclusively made4 ,h(mann /udi$ ! products ?us obta9$1 & %[$ t !y 7 d]ivatives ( a base he call$ rosanil9e2 & he demon/rat$ t ! col\r+ matt]s 7 only produc$ ?r\gh ! concurr5t pres5ce ( anil9e & toluid9e4 ,he also prov$ t ! base ( ! dye1 kn[n z anil9e blue1 0 triph5ylrosanil9e4 ,z ! result ( ^! inquiries he obta9$ ! violet or purple col\r+ matt]s kn[n by 8 "n4 ,la/ly1 all 8 classical "w on ! am9es1 ammonium comp\nds1 & ! analog\s phosphorus d]ivatives 0 done at ! ,royal ,college ( ,*emi/ry4 ,prior to ! e/abli%m5t by ,liebig1 9 #ahbf1 ( ! ,giess5 laboratory1 ! /ate ( *emi/ry 9 ,g]many 0 n mu*1 if at all1 bett] ?an ) u4 ,! creation ( ! ,giess5 s*ool initiat$ a movem5t :i* has culm9at$ 9 ! pre-em95t position :i* ,g]many n[ occupies 9 ! *emical _w4 ,/ud5ts f e civilis$ c\ntry came to /udy & to "w "u its lead]1 & to c>ry away ) !m ! influ5ce ( 8 example1 ! inspiration ( 8 g5ius1 & ! /imulat+ p[] ( 8 en?usiasm4 ,ju/us von ,liebig1 0 born at ,d>m/adt on ,may #ab1 #ahjc1 & aft] graduat+ at ,erlang51 :]e he work$ on ! fulm9ates1 he repair$ to ,p>is & ent]$ ! laboratory ( ,gay ,lussac1 ) :om he cont9u$ 8 inquiries4 ,return+ to ,g]many1 he 0 appo9t$ ,pr(essor ( ,*emi/ry at ,giess5 9 #ahbf1 & began ^? rem>kable s]ies ( sci5tific contributions ^u :i* ! sup]/ructure ( organic *emi/ry l>gely re/s4 ,he inve/igat$ ! cyanates1 cyanides1 f]rocyanides1 ?iocyanates1 & _! d]ivatives4 ,9 conjunction ) ,whl] he discov]$ ! gr\p ( ! b5zoic comp\nds & creat$ ! radical !ory4 ,) ,whl] also he inve/igat$ uric acid & its d]ivatives4 ,he discov]$ hippuric acid1 fulm9uric acid1 *loral1 *lor(orm1 aldehyde1 ?iald9e1 b5zil1 & elucidat$ ! con/itution ( ! organic acids & ! amides4 ,he greatly improv$ ! me?ods ( organic analysis1 & 0 !reby enabl$ to det]m9e ! empirical =mul ( a numb] ( c>bon comp\nds ( :i* ! composition 0 imp]fectly kn[n4 ,he practically laid ! f\ndations ( mod]n agricultural *emi/ry1 & to 8 tea*+ is due ! e/abli%m5t ( an important bran* ( te*nology--! manufacture ( *emical f]tilis]s4 ,he work$ on physiological *emi/ry1 especially on ! elaboration ( fat1 on ! nature ( blood1 bile1 & on ! juice ( fle%4 ,he /udi$ ! processes ( f]m5tation1 & ( ! decay ( organis$ matt]4 ,he 0 a mo/ prolific writ]4 ,! ,royal ,society's ,catalogue ( ,sci5tific ,pap]s enum]ates no few] ?an #cag contributions f 8 p54 ,he 0 ! f\nd] ( ! ,annal5 d] ,*emie1 :i* is n[ associat$ ) 8 "n1 & ( ! ,jahresb]i*t2 he publi%$ an ,encyclopdia ( ,pure & ,appli$ ,*emi/ry & a ,h&book ( ,organic ,*emi/ry4 ,8 ,famili> ,lett]s on ,*emi/ry 0 translat$ into e mod]n language1 & ex]cis$ a p[]ful influ5ce 9 develop+ popul> appreciation ( ! value & utility ( sci5ce4 ,liebig left ,giess5 9 #aheb to become ,pr(essor ( ,*emi/ry at ! ,univ]sity ( ,muni* & ,presid5t ( ! ,academy ( ,sci5ces4 ,he di$ at ,muni* on ,april #ah1 #ahgd4 ,) ! "n ( ,liebig t ( ,whl] is indissolubly connect$4 ,al?\gh ! great] "p ( _! "w 0 n publi%$ 9 conjunction1 :at !y did toge!r ex]cis$ a pr(\nd influ5ce on ! developm5t ( *emical !ory4 ,fri$ri* ,whl] 0 born at ,es*]%eim1 ne> ,frank=t1 on ,july #ca1 #ahjj4 ,aft] /udy+ at ,m>burg1 :]e he discov]$1 indep5d5tly ( ,davy1 cyanog5 iodide1 & work$ on m]curic ?iocyanate1 he w5t to ,heidelb]g & inve/igat$ cyanic acid & its comp\nds1 "u ! direction ( ,gmel94 ,9 #ahbc he work$ ) ,b]zelius at ,/ockholm1 :]e he prep>$ "s new tung/5 comp\nds & practis$ m9]al analysis4 ,9 #ahbe he became a tea*] ( *emi/ry 9 ! ,b]l9 ,trade ,s*ool4 ,"h he succe$$ = ! fir/ "t 9 prep>+ ! metal alum9ium & 9 effect+ ! syn!sis ( urea--"o ( ! fir/ organic comp\nds to be prep>$ f inorganic mat]ials4 ,jo9tly ) ,liebig he work$ ^u mellitic & cyanic & cyanuric acids4 ,9 #ahcb ,whl]1 n[ appo9t$ to ! ,polyte*nic at ,cassel1 began ) ,liebig _! memorable inve/igation on bitt]-almond oil4 ,9 #ahcf he 0 call$ to ! ,*air ( ,*emi/ry 9 ! ,univ]sity ( ,gtt+51 & ) ,liebig attack$ ! con/itution ( uric acid & its d]ivatives--! la/ great inve/igation ! fri5ds did 9 common4 ,whl] subsequ5tly devot$ himself ma9ly to inorganic *emi/ry4 ,he isolat$ cry/all9e boron1 & prep>$ its nitrides1 discov]$ ! spontane\sly inflammable silicon hydride1 titanium nitride1 & analys$ great numb]s ( m9]als & meteorites & comp\nds ( ! r>] metals4 ,he made ,gtt+5 fam\s z a s*ool ( *emi/ry4 ,at ! "t ( ! "o & tw5tie? ye> ( 8 connection ) ! ,univ]sity x 0 f\nd t upw>ds ( #hjjj /ud5ts _h li/5$ to 8 lectures or work$ 9 8 laboratory4 ,he di$ on ,septemb] #bc1 #ahhb4 ,9 ,france1 ,dumas ex]cis$ a no less p[]ful influ5ce4 ,if ,liebig c\ld reckon among 8 pupils ,r$t5ba*]1 ,bromeis1 ,v>r5trapp1 ,gregory1 ,playfair1 ,williamson1 ,gilb]t1 ,brodie1 ,&]son1 ,glad/one1 ,h(mann1 ,w1 & ,fres5ius2 ,dumas c\ld po9t to ,b\llay1 ,piria1 ,/as1 ,mels5s1 ,wurtz1 & ,leblanc--all ( :om did yeoman s]vice 9 develop+ ! rapidly exp&+ bran* ( organic *emi/ry4 ,illu/ration3 ,,jean ,,bapti/e ,,&r ,,dumas ,jean ,bapti/e ,&r ,dumas 0 born on ,july #ad1 #ahjj1 at ,alais1 :]e he 0 appr5tic$ to an apo!c>y4 ,9 8 sixte5? ye> he w5t to ,g5eva & ent]$ ! ph>maceutical laboratory ( ,le ,roy]4 ,)\t1 app>5tly1 hav+ receiv$ any sy/ematic in/ruction 9 *emi/ry1 he comm5c$ ! "w ( inve/igation4 ,) ,co9det he e/abli%$ ! !rapeutic value ( iod9e 9 ! treatm5t ( gtre2 ) ,prevo/ he attempt$ to isolate ! active pr9ciple ( digitalis1 & /udi$ ! *emical *anges 9 ! developm5t ( ! *ick 9 ! egg4 ,9 8 tw5ty-f\r? ye> ,dumas w5t to ,p>is & became ,rptiteur de ,*imie at ! cole ,polyte*nique4 ,he jo9$ ,aud\9 & ,brongni>t 9 f\nd+ ! ,annales des ,sci5ces ,naturelles1 & began 8 great "w on ,*emi/ry ,appli$ to ! ,arts1 ( :i* ! fir/ volume appe>$ 9 #ahbh4 ,at ab\t ?is "t he devis$ 8 me?od ( det]m9+ vap\r d5sities1 & publi%$ ! results ( a numb] ( e/imations made by means ( x4 ,) ,b\llay he began an inquiry on ! comp\nd e!rs1 out ( :i* grew ! e!r9 !ory1 :i* s]v$ z a /epp+-/one to ! !ory ( comp\nd radicals--subsequ5tly elaborat$ by ,liebig & ,whl]4 ,dumas discov]$ ! nature ( oxamide & ( e?yl oxamate1 isolat$ me?yl alcohol1 & e/abli%$ ! g5]ic connection ( gr\ps ( simil>ly con/itut$ organic sub/ances1 or1 9 a ^w1 ! doctr9e ( homology4 ,8 "w on ! metaleptic action ( *lor9e ^u organic sub/ances ev5tually effect$ ! ov]?r[ ( ! electro-*emical !ory ( ,b]zelius & l$ to ! !ory ( types1 :i*1 9 ! h&s ( ,williamson1 ,laur5t1 ,g]h>dt1 & ,odl+1 0 ( great s]vice 9 expla9+ ! analogies & relation%ips ( :ole gr\ps ( organic comp\nds4 ,he work$ 9 e field ( *emi/ry4 ,he inv5t$ _m analytical processes1 e/abli%$ ! gravimetric composition ( wat] & ( air1 & revis$ ! atomic weights ( ! great] numb] ( ! elem5ts !n kn[n4 ,dumas ex]cis$ great influ5ce 9 sci5tific & academic circles 9 ,france4 ,he 0 an admirable speak]1 & _h r>e lit]>y gifts4 ,on ! creation ( ! ,empire he 0 made a ,s5ator1 & 0 elect$ a memb] ( ! ,municipal ,c\ncil ( ,p>is1 ( :i* he became presid5t 9 #ahei4 ,he di$ on ,april #aa1 #ahhd4 ,x 0 l>gely ?r\gh ! influ5ce ( ^! ma/]-m9ds t *emi/ry took a new dep>ture4 ,prior to _! "t organic *emi/ry h>dly exi/$ z a bran* ( sci5ce3 organic products1 z a rule1 7 int]e/+ only to ! ph>maci/ ma9ly by reason ( _! te*nical or m$ic9al importance4 ,b by ! middle ( ! n9ete5? c5tury ! ri*ness ( ?is hi!rto untill$ field became manife/1 & scores ( work]s ha/5$ to s[ & to reap 9 x4 ,! mo/ /rik+ feature1 inde$1 ( ! hi/ory ( *emi/ry dur+ ! pa/ sixty ye>s has be5 ! extraord9>y expansion ( ! organic section ( ! sci5ce4 ,! *emical lit]ature relat+ to ! comp\nds ( c>bon n[ exce$s 9 volume t devot$ to all ! re/ ( ! elem5ts4 ,9 ! middle ( ! n9ete5? c5tury *emi/s began to conc]n !mselves ) ! sy/ematisation ( ! results ( ! /udy ( organic comp\nds1 & some?+ l a !ory ( organic *emi/ry gradually took %ape4 ,f ?is p]iod we may date ! attempts at express+ ! int]nal nature1 con/itution1 & relations ( sub/ances :i*1 /ep by /ep1 h culm9at$ 9 our pres5t repres5tations ( ! /ructure & spatial arrangem5t ( molecules4 ,9 #ahej ! duali/ic conceptions ( ,b]zelius ceas$ to influ5ce ! doctr9es ( organic *emi/ry4 ,! enunciation by ,dumas ( ! pr9ciple ( sub/itution1 & its logical outcome 9 ! nucleus !ory & 9 ! !ory ( types1 _h n only effect$ ! ov]?r[ ( dualism1 b 0 und]m9+ ! position ( ! radical !ory ( ,liebig & ,whl]4 ,! tea*+ ( ,g]h>dt & ,laur5t _h spread ov] ,europe1 & 0 influ5c+ ^? y\ng] *emi/s :o1 :ile r5\nc+ dualism1 7 n :olly satisfi$ ) a belief 9 comp\nd radicals4 ,williamson's discov]y1 9 #ahej1 ( ! true nature ( e!r & ( its relation to alcohol1 & 8 subsequ5t prep>ation ( mix$ e!rs1 s]v$ n only to reconcile conflict+ int]pretations ( ! process ( e!rification1 b also to reconcile ! !ory ( types ) t ( radicals4 ,la/ly1 8 me?od ( repres5t+ ! con/itution ( ! e!rs & _! mode ( orig9 gave a p[]ful /imulus to ! use ( type-=mul 9 express+ ! nature & relations ( organic comp\nds4 ,illu/ration3 ,,?omas ,,graham4 ,f a pa9t+ by ,g4 ,f4 ,watts1 ,r4,a41 9 ! possession ( ! ,royal ,society4 ,o!r repres5tative m5 ( ! middle p]iod ( ! n9ete5? c5tury1 9 addition to ,williamson1 7 ,graham & ,buns54 ,! ?ree m5 7 inve/igators ( v diff]5t type1 & _! "w _h little 9 common4 ,b ea* 0 id5tifi$ ) discov]ies ( a fundam5tal "*1 con/itut+ turn+-po9ts 9 ! hi/ory ( *emical progress1 valuable ei!r z reg>ds _! be>+ on *emical doctr9e or z reg>ds _! influ5ce on op]ative *emi/ry4 ,?omas ,graham 0 born 9 ,glasg[ on ,decemb] #ba1 #ahje1 &1 aft] /udy+ "u ,?omas ,?omson at ! ,univ]sity ( t city1 att5d$ ! lectures ( ,hope & ,leslie 9 ,ed9burgh4 ,9 #ahcj he succe$$ ,ure z tea*] ( *emi/ry at ,&]son's ,college 9 ,glasg[1 & 9 #ahcg 0 call$ to ! ,*air ( ,*emi/ry 9 ! newly-f\nd$ ,univ]sity ( ,london1 9 succession to ,edw>d ,turn]4 ,9 #ahed he 0 made ,ma/] ( ! ,m9t4 ,he di$ 9 ,london on ,septemb] #af1 #ahfi4 ,graham's "w 0 ma9ly devot$ to t section ( ! sci5ce n[ kn[n z physical *emi/ry4 ,8 contributions to pure *emi/ry are few 9 numb]4 ,by f> ! mo/ important is 8 discov]y ( metaphosphoric acid & its relations to ! o!r modifications ( phosphoric acid4 ,or?o- or ord9>y phosphoric acid 0 kn[n to ,boyle2 pyrophosphoric acid 0 discov]$ by ,cl>k4 ,graham's "w is notewor?y z fir/ def9itely indicat+ ! inh]5t prop]ty ( ! acids to comb9e ) v>iable b def9ite am\nts ( basic sub/ances by successive replacem5t ( hydroxyl gr\ps--! prop]ty we n[ t]m basicity1 & 0 ( fundam5tal importance 9 reg>d to its be>+ on ! con/itution ( acids & salts4 ,graham's fame *iefly re/s ^u 8 discov]y ( ! law ( gase\s diffusion 7#ahbi-ahca71 ^u 8 "w on ! diffusion ( liquids1 & ^u 8 recognition ( ! cond5s$ =m ( hydrog5 he t]m$ hydrog5ium4 ,que/ions involv+ ! conception ( molecul> mobility1 inde$1 con/itut$ ! ma9 feature ( 8 inquiries4 ,we owe to him1 among o!rs1 ! t]ms cry/alloid1 colloid1 dialysis1 atmolysis1 occlusion--all ( :i* h tak5 a p]man5t place 9 ! t]m9ology ( sci5ce4 ,illu/ration3 ,,alex&] ,,william ,,williamson4 ,alex&] ,william ,williamson 0 born at ,w&swor?1 ,london1 on ,may #a1 #ahbd4 ,8 fa!r1 a ,scot*man & a fell[-cl]k ( ,james ,mill 7! fa!r ( ,john ,/u>t ,mill7 9 ! ,ea/ ,india ,h\se1 took an active %>e 9 ! f\ndation1 9 #ahbf1 ( ! ,univ]sity ( ,london1 subsequ5tly kn[n z ,univ]sity ,college4 ,9 #ahdj ! y\ng] ,williamson ent]$ ! ,univ]sity ( ,heidelb]g ) ! int5tion ( /udy+ m$ic9e2 b1 "u ! influ5ce ( ,leopold ,gmel91 he turn$ to *emi/ry4 ,9 #ahdd he w5t to ,giess51 to "w "u ,liebig1 & !re made 8 fir/ contributions to *emical sci5ce--viz41 on ! decomposition ( oxides & salts by *lor9e2 on ozone2 & on ! blue comp\nds ( cyanog5 & iron4 ,aft] graduat+ at ,giess5 he w5t1 9 #ahdf1 to ,p>is1 :]e he came "u ! influ5ce ( ,comte1 ) :om he /udi$ ma!matics4 ,9 #ahej1 at ,graham's solicitation1 he 0 appo9t$ to ! ,*air ( ,practical ,*emi/ry at ,univ]sity ,college1 vacant by ! dea? ( ,f[nes4 ,he at once emb>k$ ^u ^? rese>*es :i* con/itute 8 ma9 contribution to sci5ce4 ,9 ! attempt to build up ! homolog\s s]ies ( ! aliphatic alcohols f ord9>y alcohol he succe$$ 9 demon/rat+ ! real nature ( e!r & its g5etic relation to alcohol1 & 9 expla9+ ! process ( e!rification4 ,! memoirs 7#ahej-eb7 9 :i* he embodi$ ! facts _h an imm$iate influ5ce on ! developm5t ( *emical !ory4 ,8 explanation ( ! process ( e!rification famili>is$ *emi/s ) ! idea ( ! ess5tially dynamical nature ( *emical *ange4 ,he import$ ! conception ( molecul> mobility n only into ! explanation ( su* meta!tical reactions z ! =mation ( ! e!rs1 b into ! int]pretation ( ! ph5om5a ( *emical *ange 9 g5]al4 ,9 ^! pap]s1 z also 9 "o on ! con/itution ( salts1 publi%$ 9 #ahea1 he attempt$ to sy/ematise ! repres5tation ( ! con/itution & relations ( oxidis$ sub/ances--organic & inorganic--by %[+ h[ !y may be reg>d$ z built up ^u ! type ( wat] consid]$ z ,h ,o1 ,h 9 :i* ! hydrog5 atoms are replac$1 :olly or 9 "p1 by o!r *emically equival5t atoms4 ,?is idea 0 imm$iately adopt$ by ,g]h>dt1 0 fur!r elaborat$ by ,odl+ & ,kekul1 & 0 ev5tually develop$ into a !ory ( *emi/ry4 ,williamson cont9u$ to direct ! laboratory ( ,univ]sity ,college until #ahhg1 :5 he retir$ to ! c\ntry4 ,he di$ at ,h9dhead on ,may #f1 #aijd4 ,rob]t ,wilhelm ,buns5 0 born at ,gtt+5 on ,m>* #ca1 #ahaa1 & aft] /udy+ *emi/ry "u ,/romey]1 ! discov]] ( cadmium1 w5t to ,p>is & work$ ) ,gay ,lussac4 ,9 #ahcf he succe$$ ,whl] z tea*] ( *emi/ry 9 ! ,polyte*nic ,s*ool ( ,cassel1 & 9 #ahdb became ,pr(essor ( ,*emi/ry 9 ! ,univ]sity ( ,m>burg4 ,9 #aheb he 0 call$ to ,heidelb]g1 & occupi$ ! ,*air ( ,*emi/ry !re until 8 retirem5t 9 #ahhi4 ,he di$ at ,heidelb]g on ,augu/ #af1 #ahii4 ,illu/ration3 ,,buns51 ,,kir*h(f1 ,,& ,,roscoe4 ,buns5 fir/ di/+ui%$ himself by 8 classical "w on ! cacodyl comp\nds1 obta9$ z ! result ( an inquiry into ! nature ( ! s-call$ 8fum+ liquor ( ,cadet10 an evil-smell+1 highly poison\s1 inflammable liquid =m$ by heat+ ars5i\s oxide ) an alkal9e acetate4 ,! inve/igation 7#ahcg-ahde7 is notewor?y1 n only = ! skill x exhibits 9 deal+ ) a difficult & highly dang]\s manipulative problem1 b also = ! rem>kable nature ( its results & on acc\nt ( _! influ5ce on contempor>y *emical !ory4 ,! rese>*1 9 ! words ( ,b]zelius1 0 ! f\ndation-/one ( ! !ory ( comp\nd radicals4 ,! "n cacodyl or kakodyl 0 sugge/$ by ,b]zelius 9 allusion to ! nause\s smell ( ! comp\nds ( ! new radical ars9$ime?yl1 ,z 7,,*#c7b1 z x 0 subsequ5tly t]m$ by ,kolbe4 ,buns5 greatly improv$ ! me?ods ( gasometric analysis2 ^! he appli$1 9 conjunction ) ,playfair1 to an exam9ation ( ! gase\s products ( ! bla/ furnace 9 ! manufacture ( iron1 & !reby demon/rat$ ! enorm\s wa/e ( en]gy occasion$ by all[+ ! gases to escape unus$ into ! air1 z 0 !n ! univ]sal practice4 ,?is inquiry effect$ a revolution 9 ! manufacture ( iron z important1 inde$1 z t due to ! introduction ( ! hot bla/4 ,buns5 devis$ me?ods = det]m9+ ! solubility ( gases 9 liquids1 = asc]ta9+ ! specific gravity ( gases1 _! rates ( diffusion1 & ( comb9ation or inflammation4 ,9 #ahda he inv5t$ ! c>bon-z9c batt]y1 & appli$ x to ! electrolytic production ( metals1 notably ( magnesium1 ! prop]ties ( :i* he fir/ accurately describ$4 ,9 #ahdd he contriv$ ! grease-spot photo-met]1 :i* 0 long 9 g5]al use = asc]ta9+ ! photometric value ( illum9at+ gas4 ,8 me?ods ( asc]ta9+ ! specific heats ( solids & liquids 7 simple1 +5i\s1 & accurate4 ,9 #ahee-ahfc he c>ri$ out1 9 conjunction ) ,roscoe1 a long s]ies ( inve/igations on ! *emical action ( light4 ,9 #ahei1 9 association ) ,kir*h(f1 he devis$ ! fir/ me?ods ( spectrum analysis1 & expla9$ ! orig9 & significance ( ! ,fraunh(] l9es 9 ! sol> spectrum1 ?us lay+ ! f\ndations ( sol> & /ell> *emi/ry4 ,! application ( ! spectroscope to analytical *emi/ry almo/ imm$iately result$ 9 8 discov]y ( csium & rubidium4 ,buns5 work$ on problems ( *emical geology1 & made a long s]ies ( analyses ( volcanic products4 ,) ,s*is*k(f1 he exam9$1 9 #aheg1 ! products ( fir$ gunp[d]4 ,he effect$ _m improvem5ts 9 analytical *emi/ry2 devis$ ! iodiometric me?od ( volumetric analysis1 & sy/ematis$ ! processes ( wat] analysis4 ,la/ly1 he inv5t$ ! gas-burn]--a piece ( app>atus ) :i* 8 "n is insep>ably associat$1 & :i* has be5 ( ine/imable s]vice to op]ative *emi/ry & 9 ! arts4 ,buns5 0 no !ori/1 & purely speculative que/ions _h little or no int]e/ = him4 ,at ! same "t he 0 a great tea*]1 & made ! *emical s*ool ( ,heidelb]g no less fam\s ?an ! s*ools ( ,giess5 & ,gtt+54 99 99 99 99 99 ,! mass ( mat]ial relat+ to ! developm5t ( *emi/ry :i* has be5 accumulat$ dur+ ! pa/ sixty ye>s is s va/ t x w\ld be hopeless to attempt to survey x 9 detail )9 ! limits ( su* a "w z ?is4 ,nor1 inde$1 is ?is requir$ 9 a hi/ory ( ?is "*4 ,^? :o desire in=mation conc]n+ ! orig9 & sequ5ce ( ! facts :i* collectively make up ! sup]/ructure ( mod]n *emi/ry mu/ be ref]r$ to ! encyclopdias or l>g] treatises--or1 pref]ably1 to ! num]\s monographs1 deal+ ) special sections1 :i* ! volume & complexity ( ! matt] to be dealt ) seem to r5d] increas+ly necess>y4 ,all we c d "h is to attempt to %[ :at has be5 ! ma9 outcome ( ?is sixty ye>s ( incessant ef=t to elucidate ! my/]ies ( *emical ph5om5a & to asc]ta9 ! nature ( ! conditions :i* control1 modify1 or det]m9e !m4 ,all ?is ef=t is ultimately direct$ to ! solution ( ! fundam5tal problem ( ! con/itution ( matt]4 ,! mo/ significant result ( ?is endeav\r has be5 ! elaboration & consolidation ( ! doctr9e ( *emical atoms1 n necess>ily ( atoms 9 ! limit$ ,daltonian s5se1 b ( atoms consid]$ z associations ( p>ticles1 or corpuscles--t is1 ( entities :i* may be divisible1 b :i*1 9 ! ma91 are n divid$ 9 ! va/ numb] ( ! trans=mations 9 :i* !y are conc]n$4 ,?is modification ( ! orig9al conception ( ,dalton has be5 ?\ght by "s to de/roy ! basis ^u :i* 8 !ory really re/s4 ,!re is no necessity = su* an assumption4 ,s pron\nc$ an atomi/ z ,graham1 z f> back z #ahfc1 9 a sugge/ive pap] entitl$ ,speculative ,ideas on ! ,con/itution ( ,matt]1 enl>g$ ! conception ( ! ,daltonian atom 9 precisely ! s5se :i* rec5t exp]im5tal "w appe>s to require4 ,! pres5t position1 too1 z x affects *emi/s1 0 equally well /at$ by ,kekul1 9 #ahfg1 9 ! foll[+ t]ms3 ,! "q :e!r atoms exi/ or n has b little significance f a *emical po9t2 its discussion belongs r to metaphysics4 ,9 *emi/ry we h only to decide :e!r ! assumption ( atoms is an hypo!sis adapt$ to ! explanation ( *emical ph5om5a4 ,m especially h we to consid] ! "q :e!r a fur!r developm5t ( ! atomic hypo!sis promises to advance our k ( ! me*anism ( *emical ph5om5a4 ,i h no hesitation 9 say+ t1 f a philosophical po9t ( view1 ,i d n believe 9 ! actual exi/5ce ( atoms1 tak+ ! ^w 9 its lit]al signification ( indivisible p>ticles ( matt]2 ,i r expect t we %all "s day f9d = :at we n[ call atoms a ma!matico-me*anical explanation :i* w r5d] an acc\nt ( atomic weight1 ( atomicity1 & ( num]\s o!r prop]ties ( ! s-call$ atoms4 ,z a *emi/1 h[ev]1 ,i reg>d ! assumption ( atoms n only z advisable1 b z absolutely necess>y1 9 *emi/ry4 ,i w ev5 g fur!r1 & decl>e my belief t *emical atoms exi/1 provid$ ! t]m be und]/ood to d5ote ^? p>ticles ( matt] :i* und]go no fur!r division 9 *emical metamorphoses4 ,%\ld ! progress ( sci5ce lead to a !ory ( ! con/itution ( *emical atoms--important z su* a k might be = ! g5]al philosophy ( matt]--x w\ld make b little alt]ation 9 *emi/ry itself4 ,! *emical atoms w always rema9 ! *emical unit2 & = ! specially *emical consid]ations we may always />t f ! con/itution ( atoms1 & avail ourselves ( ! simplifi$ expression ?us obta9$--t is to say1 ( ! atomic hypo!sis4 ,we may1 9 fact1 adopt ! view ( ,dumas & ( ,f>aday--t1 :e!r matt] be atomic or n1 ?us mu* is c]ta93 t1 grant+ x to be atomic1 x w\ld appe> z x n[ does4#a #a ,! ,/udy ( ,*emical ,composition1 by ,ida ,freund 7,cambridge ,univ]sity ,press71 #aijd4 ,! great] "p ( t :i* foll[s w be devot$1 !re=e1 to an exposition ( c]ta9 ( ! great advances 9 k--_m ( !m ( prim>y importance--:i* h be5 made dur+ ! la/ fifty or sixty ye>s & :i* h s]v$ to /r5g!n ?is ext5d$ conception ( ! atomic !ory1 & to e/abli% its position z an article ( ! sci5tific fai? ( ! tw5tie? c5tury4 ,,*apt] ,,ii ,,! ,,*emical ,,elem5ts ,,discov]$ ,,s9ce #ahej ,9 #ahej ! numb] ( sub/ances g5]ally recognis$ z *emical elem5ts1 9 ! s5se 9 :i* t t]m 0 fir/ employ$ by ,boyle1 0 sixty-two4 ,two memb]s--viz41 ! pelopium ( ,rose & ! ilm5ium ( ,h]mann--71 h[ev]1 subsequ5tly %[n to be id5tical ) metals already kn[n4 ,at ! pres5t "t 7#aiaj7 ! numb] ( ! *emical elem5ts def9itely recognis$ z su* is eighty-two4 ,9 #ahej1 z n[1 !y 7 broadly classifi$ z metals & non-metals1 al?\gh x 0 felt !n1 no less /rongly ?an n[1 t no v cle> l9e ( dem>cation 0 traceable betwe5 ! two gr\ps4 ,sixty ye>s ago ! elem5ts usually /yl$ non-metals 7 ?irte5 9 numb]2 to-day ! numb] is n9ete5--! increase be+ due to ! inclusion ( ars5ic & ! discov]y ( ! s-call$ inactive elem5ts1 helium1 argon1 krypton1 neon1 & x5on4 ,9 #ahej !re 7 =ty-sev5 elem5ts def9itely class$ z metals2 9 #aiaj ! numb] is sixty-?ree4 ,at all p]iods 9 ! hi/ory ( *emi/ry z a sci5ce ! g5]al t5d5cy has be5 to "n sub/ances1 :5ev] possible1 9 accordance ) ! !oretical conceptions ( ! "t1 & h5ce x has happ5$ t ! same body at successive p]iods has _h v dissimil> names4 ,b 9 nam+ ! sub/ances we t]m elem5ts1 !oretical conceptions are n usually applicable4 ,oxyg51 x is true1 d]ives its "n f su* a conception2 &1 etymologically1 ! "n connotes an error4 ,hydrog51 too1 has no m "r to be call$ ! wat] =m] ?an oxyg54 ,davy1 :o inv5t$ ! t]m *lor9e1 advocat$ t ! *emical elem5ts %\ld be nam$ f "s di/+ui%+ peculi>ity1 ei!r ( orig9 or ( physical prop]ty4 ,9 ! ma9 ?is pr9ciple has be5 adopt$ especially 9 lat] ye>s al?\gh !re are num]\s in/ances ( names d]iv$ f pure arbitr>y s\rces4 ,x is l>gely = ! reason t ! names ( ! elem5ts are1 ) r>e exceptions1 unconnect$ ) !ories t !y h rema9$ un*ang$1 :]eas names ( comp\nds1 :i* are f> m frequ5tly dep5d5t ^u speculative ideas1 h con/antly be5 alt]$ 9 ord] to comply ) ! prevail+ hypo!ses ( ! p]iod4 ,at ! same "t x is n always cle> t ! etymology ( c]ta9 ( ! elem5ts is well asc]ta9$4 ,x has be5 rec5tly %[n1 = example t ! commonly accept$ orig9 ( ! ^w 8antimony0 f antimo9e1 bas$ on ! alleg$ exp]i5ces ( m$ival ecclesia/ics has no valid f\ndation4 ,! ^w is1 9 reality1 d]iv$ f ! ,arabic alhm\d3 ?is became lat9is$ to al?imodium & ev5tually to antimonium4 ,by ! middle ( ! n9ete5? c5tury ! sy/em ( symbolical notation sugge/$ by ,b]zelius 0 ev]y:]e curr5t2 &1 /ripp$ l>gely ( its duali/ic associations1 ?is sy/em /ill rema9s ! mo/ g5]ally conv5i5t me?od ( express+ ! composition1 analogies1 & num]ical relations ( sub/ances4 ,dur+ ! middle ( ! la/ c5tury philosophic *emi/s1 al?\gh subscrib+1 ) h>dly an exception1 to ! doctr9e ( def9ite comb9+ proportions1 7 by no means agre$ z to ! suffici5cy ( ,dalton's explanation ( ! exp]im5tal laws ( *emical comb9ation2 & ! hypo!sis ( atoms 9 ! ,daltonian s5se 0 n univ]sally accept$4 ,to "s ! atomic !ory ( ,dalton1 :i* assum$ t ! comb9+ proportion 0 id5tical ) ! relative weight ( ! atom1 0 unnecess>y z an explanation ( ! laws ( comb9ation4 ,or at mo/ x 0 only "o out ( a v>iety ( molecul> conditions 9 :i* matt] might exi/4 ,consequ5tly "s *emi/s 7 9 ! habit ( draw+ a di/9ction betwe5 *emical atoms & physical atoms4 ,! *emical atom 0 id5tical ) ! ,daltonian atom b ?is 0 by no means ! same z ! physical atom ( ,democritus or ,leucippus4 ,! view 9 #ahej1 9 fact1 0 n v dissimil> f t to :i* rec5t exp]im5tal inquiry has l$4 ,b x c h>dly be said t ! d\bts 7 dep5d5t ^u valid exp]im5tal evid5ce2 !y arose r f ! errone\s int]pretation ( imp]fectly asc]ta9$ facts--^u ! suppos$ inconsi/5cies ( ! law ( ,gay ,lussac ) ! hypo!ses ( ,avogadro & ,ampre4 ,z soon z ! facts 7 cle>ly p]ceiv$ & ! inconsi/5cies reconcil$ we he>d less ( ! suppos$ di/9ction betwe5 ! *emical & ! physical atom4 ,x is only )9 q rec5t "t1 & z ! result ( entirely new l9es ( inquiry1 t ! di/9ction has be5 reviv$4 ,9 ! e>ly "p ( ! la/ c5tury attempts 7 made by ,b]zelius to classify ! *emical elem5ts accord+ to _! electro-*emical relations1 & by ,?omson accord+ z !y 7 8support]s0 or 8non-support]s ( combu/ion40 ,x 0 soon p]ceiv$ t ,?omson's sy/em _h no philosophical basis1 & x quickly fell into disuse4 ,aft] ! discov]y ( isomorphism1 an endeav\r 0 made by ,graham to arrange ! simple bodies 9 accordance ) _! natural relations1 & ev5 be=e #ahej ! v>i\s elem5ts 7 gr\p$ by him v mu* z n[4 ,?is s*eme ( classification1 some:at modifi$ by consid]ations ( val5cy1 & occasionally correct$ by m accurate in=mation conc]n+ true analogies 7z :5 vanadium 0 transf]r$ by ,roscoe to ! nitrog5 gr\p71 0 9 g5]al use = practically a qu>t] ( a c5tury--9 fact1 until x 0 sup]s$$ by ! gradual adoption ( ,m5deleff's arrangem5t bas$ on p]iodicity4 ,!re c1 h[ev]1 be little d\bt t ?is attempt by ,graham at a natural classification pav$ ! way along :i* ,newl&s & ev5tually ,m5deleff 7 l$ to devise our pres5t rational sy/em ( gr\p+ ! *emical elem5ts4 ,! num]ical relation%ips exi/+ among ! equival5ts & atomic weights ( ! elem5ts ( c]ta9 ( ^! gr\ps1 po9t$ out by ,dumas1 ,pett5k(]1 ,odl+1 ,glad/one1 & o!rs1 gave rise to mu* speculation4 ,! values ( ! gradational diff]5ces1 ( c\rse1 dep5d$ ^u :e!r equival5ts or atomic weights 7 employ$2 b ! imm$iate po9t is t1 :i*ev] basis 0 adopt$1 def9ite num]ical relations 7 to be p]ceiv$4 ,?us1 9 ! case ( ! gr\p ( ! halog5s1 x 0 po9t$ out t ! individual memb]s are connect$ toge!r z foll[s3 ,fluor9e4 ,*lor9e4 ,brom9e4 ,iod9e4 #ai #ce4e #hj #abg a a d a #b;d d #b;a #b;d #b;d :]e a #ai2 d #af4e2 d #bh4 ,?us1 too1 9 ! case ( ! nitrog5 gr\p3 ,nitrog54 ,phosphorus4 ,ars5ic4 ,antimony4 ,bismu?4 #ad #ca #ge #aai #bjg a a d a d d a d #b;d a d #d;d :]e a #ad2 d #ag2 d #dd4 99 99 99 99 99 ,on ! basis ( ^! & simil> num]ical relation%ips x 0 surmis$ t1 j z ! successive memb]s ( a gr\p ( homolog\s organic radicals are =m$ by increm5ts ( ,,*#b1 s ! sub/ances 9 ! sev]al gr\ps ( ! elem5ts may be produc$ by successive additions ( "s =m ( matt] common to !m all4 ,?is has its c\nt]p>t1 some:at modifi$1 9 ! mod]n hypo!sis ( ! dis9tegration ( ! elem5ts4 ,dumas conceiv$ ! elem5ts 9 any p>ticul> gr\p to be built up by successive accretions ( p>ticul> =ms ( matt]2 ,ru!r=d & ,soddy suppose !m to be d]iv$ by ! successive elim9ation ( matt] f "s un/able p>5t sub/ance4 ,s9ce #ahej ! exi/5ce ( at lea/ tw5ty-two new elem5ts may be said to h be5 e/abli%$4 ,( c\rse1 _m m ?an ?is numb] h be5 ann\nc$1 m or less t5tatively2 b subsequ5t inve/igation has ei!r n confirm$ _! exi/5ce1 or has def9itely disprov$ x4 ,! names1 symbols1 & atomic weights ( ! tw5ty-two1 arrang$ 9 alphabetical ord]1 are z foll[s3 ,argon ,a #ci4i ,csium ,cs #acb4h ,dysprosium ,dy #afb4e ,europium ,eu #aeb4j ,gadol9ium ,gd #aeg4c ,gallium ,ga #fi4i ,g]manium ,ge #gb4e ,helium ,he #d4j ,indium ,9 #aad4h ,krypton ,kr #hc4j ,lutecium ,lu #agd4j ,neodymium ,nd #add4c ,neon ,ne #bj4j ,praseodymium ,pr #adj4f ,radium ,ra #bbf4d ,rubidium ,rb #he4d ,sam>ium ,sa #aej4d ,sc&ium ,sc #dd4a ,?allium ,tl #bjd4j ,?ulium ,tm #afh4e ,x5on ,xe #acj4g ,ytt]bium ,yb #agb4j 7,neoytt]bium7 ,! additions h be5 due1 to "s ext5t1 to ! ref9em5t ( processes ( analysis already 9 use1 b m especially to ! employm5t ( new analytical me?ods2 or1 la/ly1 to ! application ( a g5]alisation conc]n+ ! mutual relations ( ! elem5ts :i* has s]v$ to indicate n only ! exi/5ce ( new & specific memb]s ( families ( elem5ts already kn[n1 b to po9t out ! probable mode ( _! occurr5ce4#b #b ,! sub/ances :i* appe> to be =m$ by ! dis9tegration ( uranium1 radium1 ?orium--! s-call$ radio-active elem5ts--su* z ionium1 act9ium1 polonium1 & ! v>i\s emanations to :i* !y give rise1 are n "h enum]at$4 ,!y are dealt ) 9 ,*apt] ,,iii4 ,al?\gh ! exi/5ce ( ! elem5t fluor9e 0 surmis$ z f> back z #agga1 :5 ,s*eele fir/ recognis$ t ! product ( ! action ( oil ( vitriol ^u fluor-sp> conta9$ a hi!rto unkn[n sub/ance1 x 0 n until #ahhf t ?is sub/ance 0 def9itely isolat$ by ,moissan by ! electrolysis ( ! acid potassium fluoride 9 solution 9 hydrog5 fluoride4 ,c]ium tetrafluoride1 ,ce,f#d1 & lead tetrafluoride1 ,pb,f#d1 :5 heat$1 7 obs]v$ by ,braun] to evolve a gas hav+ a smell resembl+ t ( hypo*lor\s acid1 :i* 0 probably free fluor9e4 ,c]ta9 violet-col\r$ v>ieties ( fluor-sp>1 :5 p[d]$1 emit a peculi> smell1 :i* has be5 attribut$ to free fluor9e4 ,gore obs]v$ t anhydr\s hydrog5 fluoride w\ld n conduct electricity--a fact confirm$ by ,moissan4 ,moissan f\nd1 h[ev]1 t on add+ potassium fluoride to ! liquid x readily suff]$ electrolysis ) ! lib]ation ( free fluor9e z a light gre5i% yell[ gas ) a pung5t1 irritat+ smell resembl+ t ( hypo*lor\s acid4 ,x has a vap\r d5sity correspond+ ) an atomic weight #ai4 ,by ! application ( cold & pressure x may be liquefi$4 ,at /ill l[] temp]atures x may be froz5 to a :ite solid4 ,fluor9e is *>act]is$ by an extraord9>y *emical activity1 & comb9es1 ev5 at ord9>y temp]atures1 ) a l>ge numb] ( sub/ances4 ,sulphur1 phosphorus1 ars5ic1 antimony1 boron1 iod9e1 & silicon inflame or become inc&esc5t 9 contact ) x4 ,x comb9es ) hydrog5 ) explosive viol5ce1 ev5 9 ! d>k & at ! l[e/ temp]ature4 ,x unites also ) ! metals1 occasionally ) inc&esc5ce1 & decomposes wat] ) lib]ation ( oxyg54 ,! application1 by ,buns51 ( ! spectroscope to *emical analysis almo/ imm$iately result$ 9 8 discov]y1 9 #ahfj1 ( csium1 &1 9 #ahfa1 ( rubidium4 ,csium 0 fir/ detect$ 9 ! m9]al wat] ( ,drkheim 9 ! ,palat9ate & 9 ! m9]al petalite1 by ! two blue l9es x =ms 9 ! spectrum1 :5ce its "n f ! ,lat9 csius1 us$ to designate ! blue ( ! cle> sky4 ,rubidium 0 f\nd 9 a lepidolite by means ( a numb] ( l9es 9 diff]5t p>ts ( ! spectrum n previ\sly obs]v$1 two be+ especially rem>kable 9 ! out]mo/ region ( ! visible r$ portion--:5ce ! "n ( ! elem5t f ! ,lat9 rubidus1 us$ to designate ! d>ke/ r$ col\r4 ,! new metals 7 f\nd to h ! close/ analogies to potassium1 ) :i* !y usually occur associat$ 9 nature4 ,rubidium is f\nd 9 a numb] ( lepidolites1 leucite1 spodum5e1 triphylite1 mica1 & or?oclase1 & 9 ! ,/assfurt c>nallite2 9 sea-wat] & 9 _m m9]al wat]s4 ,x occurs also 9 ! a%es ( _m plants su* z ^? ( beetroot1 tobacco1 tea1 c(fee1 etc4 ,x is d\btful if x is a normal con/itu5t ( plant food1 attempts to introduce x 9 place ( pota% hav+ fail$4 ,x is n improbable t ^! elem5ts w\ld h rema9$ unkn[n except = spectrum analysis4 ,at all ev5ts1 "o ( !m--csium--0 miss$ 9 #ahdf by ,plattn]1 9 ! c\rse ( ! analysis ( ! m9]al pollucite1 9 :i* x occurs to ! ext5t ( "o ?ird ( its weight4 ,aft] ! discov]y ( csium by ,buns51 ?is m9]al 0 aga9 analys$ by ,pisani1 :5 x 0 f\nd t ! alkali :i* ,plattn] _h mi/ak5 = potassium 0 9 reality csium4 ,csium is f\nd to a v small ext5t 9 _m m9]al wat]s1 9 a v>iety ( m9]als1 & 9 ! a%es ( plants4 ,9 #ahfa ,sir ,william ,crookes made kn[n ! exi/5ce ( a new elem5t :i* he call$ ?allium4 ,he f\nd x 9 a sel5if]\s deposit obta9$ f an oil ( vitriol factory 9 ! ,h>z4 ,x 0 *>act]is$ by giv+ a bright gre5 l9e 9 ! spectroscope--:5ce its "n f 1 a gre5 or budd+ twig4 ,! discov]y 0 confirm$ 9 ! foll[+ ye> by ,lamy4 ,?allium1 9 its g5]al *emical relations1 has _m analogies to ! metals ( ! alkalis al?\gh 9 ! metallic /ate x has ! close/ resemblance to lead4 ,x occurs 9 _m v>ieties ( pyrites1 9 a few m9]als1 su* z crookesite1 lor&ite1 z9c-bl5de & copp] pyrites1 etc41 & 9 c]ta9 m9]al wat]s4 ,9 #ahfc ,rei* & ,ri*t]1 by means ( ! spectroscope1 detect$ ! pres5ce ( a new elem5t 9 ! z9c-bl5de ( ,freib]g4 ,! obs]vation t x af=d$ two indigo-blue l9es 9 ! sp>k-spectrum l$ !m to give x ! "n indium4 ,x has s9ce be5 f\nd 9 num]\s bl5des1 9 v>i\s z9c & tung/5 ores1 & 9 _m iron ores4 ,x is a silv]-:ite1 ductile1 & malleable metal1 melt+ at #agd1 & burn+ :5 heat$ ) a violet flame4 ,x is relat$ 9 *emical *>act]s to alum9ium & z9c4 ,its true place 9 ! natural s*eme ( classification ( ! elem5ts 0 indicat$ by ,m5deleff4 ,9 #ahge ,lecoq de ,boisbaudran discov]$ a new elem5t 9 ! z9c-bl5de ( ,pi]refitte 9 ! ,pyr5ees1 also by means ( spectrum analysis4 ,! sp>k-spectrum ( its salts af=ds two *>act]i/ic violet l9es q diff]5t 9 position f ^? giv5 by indium4 ,to ! new elem5t its discov]] gave ! "n ( gallium4 ,x has be5 f\nd 9 v small am\nts 9 o!r bl5des1 b is /ill "o ( ! r>e/ ( ! *emical elem5ts4 ,x is a blui%-:ite1 h>d1 & slightly malleable metal fus+ at a temp]ature n mu* high] ?an t ( a hot summ] day4 ,its exi/5ce & ma9 prop]ties1 z well z its m significant *emical relation%ips1 7 pr$ict$ by ,m5deleff 9 #ahfi f consid]ations bas$ ^u 8 p]iodic law4 7,see ante47 ,9 ! same ye> ,m5deleff also pr$ict$ ! exi/5ce ( a new elem5t belong+ to ! gr\p ( :i* boron is ! fir/ memb]1 :i* he provisionally t]m$ eka-boron1 & describ$ its ma9 prop]ties4 ,m5deleff's pr$iction 0 v]ifi$ 9 #ahgi by ,nilson's discov]y ( ! elem5t sc&ium4 ,sc&ium occurs associat$ ) yttrium1 ytt]bium1 etc41 9 _m ,sw$i% m9]als1 su* z eux5ite1 gadol9ite1 yttrotitanite1 etc4 ,! metal itself has n be5 isolat$1 b ! prop]ties ( its comp\nds correspond closely ) ^? ( ! correspond+ ekaboron comp\nds1 z pr$ict$ by ,m5deleff4 ,a fur!r illu/ration ( ! value ( ! pr9ciple ( p]iodicity1 z develop$ by ,m5deleff1 9 indicat+ ! exi/5ce ( new elem5ts1 is se5 9 ! discov]y ( g]manium4 ,9 #ahhe ,weisba* discov]$ a new ,freib]g silv] m9]al1 to :i* he gave ! "n argyrodite4 ,?is on analysis by ,w9kl] 0 f\nd to conta9 a new elem5t to ! ext5t ( ab\t sev5 p] c5t4 ) prop]ties id5tical ) ^? pr$ict$ by ,m5deleff = a miss+ elem5t 9 ! f\r? gr\p ( ! p]iodic s]ies1 consi/+ ( silicon1 t91 & lead1 & :i* he _h provisionally t]m$ eka-silicon4 ,argyrodite1 9 fact1 is a d\ble sulphide ( silv] & g]manium1 #b;,ag#b,s4,ge,s#b4 ,g]manium is a greyi%-:ite1 lu/r\s metal ( sp4gr4 #e4e41 melt+ at ab\t #ijj1 & resembl+ silicon & t9 9 its g5]al *emical relations4 ,dysprosium1 europium1 gadol9ium1 lutecium1 neodymium1 praseodymium1 sam>ium1 ?ulium1 & ytt]bium 7neoytt]bium7 belong1 l sc&ium1 to ! gr\p ( ! s-call$ r>e e>? metals4 ,^! sub/ances h be5 detect$ 9 a great v>iety ( m9]als1 _m ( :i* are extremely r>e4 ,! elem5ts mo/ frequ5tly occur 9 nature associat$ ) yttrium1 c]ium1 ?orium1 & zirconium4 ,dysprosium 0 fir/ detect$1 9 #ahhf1 by ,lecoq de ,boisbaudran 9 ! s-call$ erbium e>? ( ,mos&]1 9 :i* ,cleve _h previ\sly 7#ahhj7 ann\nc$ ! exi/5ce ( two o!r elem5ts1 holmium & ?ulium4 ,!re is "s reason to believe t ! holmium ( ,cleve is id5tical ) dysprosium4 ,ytt]bium 0 discov]$ by ,m>ignac1 9 #ahgh1 9 ! m9]al gadol9ite4 ,9 #aijf ,au] von ,welsba* ann\nc$ t ,m>ignac's ytt]bia 0 a mixture1 :i* 0 confirm$ 9 ! foll[+ ye> by ,urba91 :o sep>at$ x into two elem5ts1 :i* he nam$ neoytt]bium & lutecium4 ,europium 0 discov]$ by ,dem>ay 9 #aija4 ,all ^! e>?s are met ) 9 small quantities associat$ ) yttria 9 gadol9ite1 eux5ite1 sam>skite1 x5otime1 c]ite1 or?ite1 & o!r simil> m9]als4 ,_! comp\nds1 or su* ( !m z h be5 describ$1 resemble ! correspond+ comp\nds ( yttria4 ,!y are recognis$ by diff]5ces 9 _! spectroscopic behavi\r4 ,gadol9ium 0 detect$1 indep5d5tly1 9 #ahhf1 by ,m>ignac & ,lecoq de ,boisbaudran 9 ! t]bium e>? ( ,mos&]4 ,:at 0 long kn[n z didymium 7 a tw97 0 discov]$ by ,mos&] 9 #ahda4 ,x owes its "n to its close *emical relation%ip to1 & almo/ con/ant association )1 lan?anum--bo? elem5ts occurr+ 9 _m m9]als1 m p>ticul>ly 9 c]ite1 allanite1 & monazite4 ,9 #ahhe ,au] von ,welsba* ann\nc$ t ! didymium ( ,mos&] 01 9 reality1 a mixture ( two elem5ts :i* c\ld be sep>at$ by ! sy/ematic fractional cry/allisation ( ! d\ble ammonium nitrates2 to ^! elem5ts he gave ! names praseodymium 71 leek-gre57 & neodymium 71 new74 ,neodymium salts are rose-col\r$1 :]eas ^? ( praseodymium are gre51 & ! elem5ts are fur!r *>act]is$ by diff]5ces 9 _! absorption & sp>k-spectra4 ,:5 mix$1 ! sub/ances give ! spectrum orig9ally consid]$ to be *>act]i/ic ( didymium4 ,sam>ium 0 discov]$ 9 #ahgi by ,lecoq de ,boisbaudran 9 sam>skite4 ,its salts are yell[1 & af=d 9 solution *>act]i/ic absorption b&s4 ,x is n improbable t _m ( ! m9]als f :i* ! s-call$ r>e e>?s are obta9$ conta9 elem5ts hi!rto unrecognis$1 & x is possible t c]ta9 ( ! sub/ances n[ assum$ to be elem5ts may1 l didymium1 turn out to be mixtures4 ,9 fact1 additional elem5ts h f "t to "t be5 ann\nc$1 z = example1 ! decipium ( ,delafonta9e 7#ahgh7 & ! monium or victorium ( ,crookes 7#ahii71 pron\nc$ by ,urba9 to be id5tical ) gadol9ium3 _! individuality _c z yet be said to be e/abli%$4 ,didymium itself 0 /at$ by ,krss & ,nilson 7#ahhh7 to be ev5 m complicat$ ?an ! "w ( ,au] von ,welsba* w\ld seem to indicate1 & to conta9 no few] ?an eight elem5t>y sub/ances4 ,z yet1 h[ev]1 no confirmation ( ?is surmise has be5 obta9$4 ,! *emi/ry ( ! r>e e>?s has ( late ye>s be5 greatly ext5d$ ow+ to ! employm5t ( c]ta9 ( ! memb]s ( ! gr\p 9 ! manufacture ( ! 8mantles0 us$ 9 gas-light+1 & :i* consi/ sub/antially ( ?oria1 mix$ ) ab\t "o p] c5t4 ( c]ia4 ,l>ge quantities ( monazite1 ?orianite1 ?orite1 c]ite1 & o!r m9]als1 are n[ work$ up = ! sake ( ! ?oria & c]ia !y conta91 & consid]able am\nts ( residual products1 consi/+ l>gely ( o!r memb]s ( ! family1 are n[ available = inve/igation4 ,x is reasonably c]ta91 !re=e1 t our k ( ?is section ( inorganic *emi/ry w be l>gely augm5t$ 9 ! imm$iate future4 ,inde$1 ! application ( ?oria to ! con/ruction ( gas-mantles may be said to h remov$ t sub/ance f ! category ( ! r>e elem5ts4 ,no soon] 0 x discov]$ t x 0 capable ( useful application ?an unexpect$ s\rces ( supply 7 f\nd4 ,! same result has foll[$ 9 o!r cases4 ,"o ( ! mo/ significant developm5ts ( mod]n *emi/ry is se5 9 ! ef=ts :i* are con/antly be+ made to turn ! s-call$ r>e elem5ts to useful acc\nt2 & :5 !y are f\nd to be te*nically valuable x is g5]ally obs]v$ t hi!rto unkn[n s\rces ( supply are soon available4 ,c]ium salts h be5 f\nd to be useful 9 ! col\r+ ( glass & porcela91 z mordants 9 dye+1 9 photography1 & 9 m$ic9e4 ,zirconium has be5 us$ 9 inc&esc5t electric light+1 & ?allium has be5 employ$ 9 ! manufacture ( highly refractive optical glass4 ,titanium1 molybd5um1 & vanadium are us$ 9 ! manufacture ( /eel ( high t5sile /r5g?4 ,tantalum & tung/5 are employ$ 9 ! con/ruction ( filam5ts 9 inc&esc5t electric light+4 ,tantalum1 inde$1 has be5 f\nd to occur 9 consid]able quantities1 & to be m l>gely di/ribut$ ?an 0 hi!rto suppos$4 ,alloys ( tung/5 & alum9ium are us$ 9 automobile con/ruction1 & alloys ( tung/51 alum9ium1 & copp] 9 ! manufacture ( propell] blades4 ,tung/5 /eel is us$ 9 arm\r plates1 & to /iff5 ! spr+s ( c>s2 9 ! manufacture ( piano-wire1 & to increase ! p]man5cy ( magnets4 ,ev5 ! r>] metals ( ! plat9um gr\p are f9d+ _m important applications4 ,osmium-iridium is us$ = ! be>+s ( compasses1 = ! tips ( gold p5s1 & 9 ! con/ruction ( /&>d weights4 ,osmium & ru!nium ent] into ! composition ( filam5ts = electric light+4 ,! extraord9>y influ5ce ( light on ! electric conductivity ( sel5ium has be5 made use ( 9 ! transmission ( photographs by telegraph & telephone wires1 & = measur+ ! light int5sity ( ! ,rntg5 rays 9 cl9ical "w4 ,,*apt] ,,iii ,,! ,,inactive ,,elem5ts3 ,,radium ,,& ,,radio-,,activity ,argon1 helium1 krypton1 neon1 & x5on belong to ! gr\p ( ! s-call$ inactive elem5ts1 & con/itute :at are kn[n z ! r>e gases ( ! atmosph]e4 ,! exi/5ce ( ^! bodies is ( great !oretical value & few discov]ies ( rec5t times h exact$ m int]e/ & curiosity4 ,tw5ty ye>s ago x 0 g5]ally assum$ t practically all t 0 to be kn[n conc]n+ ! composition ( atmosph]ic air _h be5 asc]ta9$4 ,prie/ley & ,cav5di% _h recognis$ t x 0 ma9ly compos$ ( oxyg5 & nitrog51 & ,cav5di% _h def9itely /at$ t ^! gases are pres5t 9 practically con/ant proportion1 indep5d5t ( season1 climate1 or locality4 ,?n>d1 ,saussure1 & o!rs1 _h det]m9$ ! limits ( v>iation 9 ! am\nt ( c>bon dioxide4 ,buns5 & ,regnault _h e/abli%$ t ! quantities ( oxyg5 & nitrog5 are subject to slight alt]ation1 ! ext5t ( :i* c\ld be readily det]m9$ by ! exact eudiometric processes !y _h devis$4 ,la/ly1 x 0 prov$ beyond a d\bt t ! gases ( ! atmosph]e are simply me*anically mix$1 & c be sep>at$ by a v>iety ( physical me?ods4 ,9 fact1 ( no s+le subject c\ld x be m confid5tly assum$ t f9ality ( k _h app>5tly be5 rea*$4 ,9 #ahib1 9 ! c\rse ( a s]ies ( det]m9ations ( ! d5sities ( ! common gases1 ,"l ,rayleigh f\nd t ! d5sity ( nitrog5 obta9$ f ! air 0 slightly great] ?an ! d5sity ( t gas prep>$ by ! decomposition ( ammonia & ( nitric acid1 ! diff]5ce 9 weight be+ ab\t #a "p 9 #bjj--;an am\nt f> great] ?an c\ld be acc\nt$ = by errors ( weigh+4 ,v>i\s suppositions 7 made 9 explanation ( ! discrepancy2 b ^!1 :5 te/$1 7 f\nd n to acc\nt = ! facts4 ,by heat+ ! atmosph]ic nitrog5 ) metallic magnesium1 :]eby ! great] portion ( ! gas is absorb$ to =m ! nitride1 ,sir ,william ,ramsay f\nd t ! d5sity ( ! residual gas 0 /ill fur!r increas$1 :i* r5d]$ x probable t ! relatively high d5sity ( atmosph]ic nitrog5 z comp>$ ) t d]iv$ f ammonia1 &1 z ,"l ,rayleigh f\nd1 f o!r s\rces also1 0 due to ! pres5ce ( a gase\s sub/ance 9 ! air ( consid]ably great] d5sity ?an nitrog5 or oxyg54 ,"l ,rayleigh also subject$ atmosph]ic nitrog5 mix$ ) oxyg5 to ! electric dis*>ge ov] a solution ( cau/ic soda1 9 a mann] simil> to t already employ$ by ,cav5di%1 & f\nd also t ! residual gas 0 consid]ably increas$ 9 d5sity4 ,at ! ,ox=d meet+ ( ! ,briti% ,association 9 ,augu/1 #ahid1 ! two inve/igators 7 9 a position to ann\nce t ! discrepancy 0 actually due to ! pres5ce ( a hi!rto unkn[n gase\s con/itu5t ( atmosph]ic air1 consid]ably m soluble 9 wat] ?an nitrog51 & to :i*1 on acc\nt ( its *emical in]tness1 ! "n ( argon 71 idle7 0 giv54 ,by a special app>atus devis$ by ,"l ,rayleigh1 9 :i* a mixture ( air & oxyg5 is submitt$ to an electric flame produc$ by a p[]ful1 rapidly alt]nat+ curr5t1 consid]able quantities ( argon 7 sep>at$ f ! air4 ,x has also be5 f\nd t by ! use ( metallic calcium or a mixture ( magnesium & lime1 ! atmosph]ic nitrog5 is absorb$ at a l[] temp]ature1 & m rapidly ?an by magnesium alone4 ,argon has be5 f\nd to exi/ 9 ! gases f spr+s & m9]al wat]s1 notably 9 ^? ( ,ba?1 ,caut]ets1 ,wildbad1 & ,h>rogate4 ,x has also be5 f\nd 9 a meteorite1 9 ! gas occlud$ 9 rock-salt1 & 9 ! m9]als malacone1 uran9ite1 brgg]ite1 etc4 ,no animal or vegetable sub/ance appe>s to conta9 x4 ,x is pres5t 9 atmosph]ic air to ! ext5t ( ab\t "o p] c5t4 by volume4 ,x is a col\rless gas ( an atomic weight ( #ci4i3 "o litre ( x at ! /&>d temp]ature & pressure weighs #a4ghae grams4 ,exp]im5ts made by ! me?od ( ,kundt & ,w>burg--i4e41 by det]m9+ ! ratio ( ! specific heats at con/ant pressure & con/ant volume by ! velocity ( s\nd 9 ! gas--prove t argon1 l m]cury gas1 is monatomic4 ,?is ( itself indicates t argon is an elem5t1 s9ce a monatomic comp\nd is a contradiction 9 t]ms4 ,! calculations f ! exp]im5tal data presuppose t argon obeys ! laws ( ,boyle & ,dalton1 :i* 0 f\nd on trial to be ! case4 ,by ! application ( cold & pressure argon c be liquefi$4 ,! liquid boils at -#ahf4a & freezes at -#ahg4i4 ,! spectrum ( ! gas is exce$+ly complicat$1 consi/+ ( a great numb] ( l9es ext5d+ ?r\gh\t ! visible portion & f> into ! extreme r$ & ultra-violet4 ,! col\r ( ! light emitt$ on sp>k+ ! gas *anges ) increase ( temp]ature f a brilliant r$ to a bright blue--dep5d+ on ! int5sity ( ! dis*>ge4 ,all attempts to induce argon to ent] into comb9ation ) o!r sub/ances h fail$4 ,! me?ods ( its prep>ation %[ t x does n comb9e ) oxyg51 al?\gh ,troo/ & ,ouvr>d /ate t x unites ) magnesium vap\r4 ,x =ms no comp\nds ) hydrog51 *lor9e1 phosphorus1 sulphur1 sodium1 tellurium1 etc4 ,ev5 fluor9e1 probably ! mo/ g5]ally active ( ! *emical elem5ts1 %[s no t5d5cy to unite ) x4 ,9 #ahhh ,dr4 ,hillebr&1 ( ! ,u4,s4 ,geological ,survey1 9 exam9+ a =m ( uran9ite kn[n z cleveite1 s nam$ f ! late ,pr(essor ,cleve1 f\nd t on treatm5t ) dilute sulphuric acid x gave (f consid]able quantities ( a gas :i* 0 assum$ to consi/ only ( nitrog51 z x gave ! spectroscopic reactions ( t elem5t4 ,to te/ :e!r ?is gas conta9$ argon1 ,ramsay1 9 #ahie1 fur!r exam9$ x spectroscopically4 ,aft] sp>k+ x ) oxyg5 9 ! pres5ce ( cau/ic soda solution1 9 ! way already describ$1 x gave no indications ( argon4 ,! ma9 *>act]i/ic ( its spectrum 0 a bright yell[ l9e1 kn[n z ,d#c1 n co9cid5t ) t af=d$ by sodium1 b id5tical 9 position ) a l9e detect$ 9 ! *romosph]e dur+ ! sol> eclipse ( #ahfh1 :i* l9e1 on exam9ation by ,frankl& & ,locky]1 c\ld n be ascrib$ to any kn[n elem5t4 ,= ?is suppos$ new elem5t ! "n helium1 f 1 ! sun1 _h be5 sugge/$4 ,?is 0 ! fir/ occasion on :i* an elem5t obs]v$ orig9ally only 9 ! sun 0 f\nd to occur also on ! e>?4 ,! pres5ce ( ! new elem5t 9 ! gas f cleveite 0 subsequ5tly confirm$ by ,langlet work+ 9 ,cleve's laboratory4 ,illu/ration3 ,,sir ,,william ,,ramsay4 ,helium is a monatomic gas hav+ ! atomic weight #d4 ,x is less soluble 9 wat] ?an argon4 ,l argon1 x %[s no t5d5cy to ent] into *emical union ) any o!r sub/ance4 ,x has be5 f\nd 9 _m m9]als1 p>ticul>ly 9 ^? conta9+ uranium & ! s-call$ r>e e>? metals4 ,x also occurs among ! gases issu+ f c]ta9 m9]al spr+s1 su* z ^? ( ,ba? & at ,caut]ets 9 ! ,pyr5ees1 & also at ,adano ne> ,padua4 ,! spectrum ( helium conta9s1 9 addition to ! *>act]i/ic yell[ l9e--by :i* its pres5ce _h be5 recognis$ n only 9 ! sol> *romosph]e1 b also 9 c]ta9 ( ! fix$ />s--two l9es 9 ! r$1 & l9es 9 ! gre51 blue1 & violet4 ,! "* ( ! light emitt$ by ! sp>k-dis*>ge is modifi$ by ! int5sity ( ! dis*>ge 9 a mann] simil> to t ( argon4 ,x has be5 %[n by ,collie t its spectrum is alt]$ by ! pres5ce ( m]cury vap\r4 ,x is ! lea/ refractive ( all ! gases4 ,helium 0 liquefi$ by ,kamm]l+h ,onnes 9 #aijh4 ,x =ms a col\rless liquid ( sp4 gr4 #j4aed1 boil+ at -#bfh4e2 t is1 #d4e above ! absolute z]o ( temp]ature4 ,its critical temp]ature is ab\t #e absolute1 & its critical pressure above #b atmosph]es4 ,! me?ods n[ 9 use = obta9+ liquid air1 ref]r$ to 9 a subsequ5t *apt]1 enable l>ge quantities ( t mat]ial to be obta9$ readily2 & x 0 9 inve/igat+ spectroscopically ! residues left aft] volatilis+ a quantity ( liquid air t ,ramsay & ,trav]s1 9 #ahih1 detect$ ! exi/5ce ( two new monatomic gase\s con/itu5ts ( ! air :i* !y nam$ respectively krypton 71 hidd57 & neon 71 new71 ! =m] heavi] & ! latt] light] ?an argon4 ,by fractional di/illation ( ! argon1 simultane\sly procur$1 a gas 0 obta9$ :i* 9 ! spectroscope %[$ ! *>act]i/ic l9es ( helium--previ\sly recognis$ 9 atmosph]ic argon by ,kays] & ,fri$lnd]--toge!r ) a complicat$ spectrum consi/+ ( a numb] ( l9es 9 ! r$1 orange1 & yell[ due to ! new elem5t neon4 ,on cool+ ?is mixture to -#beb by means ( liquid hydrog51 ! neon solidifi$1 :ile ! helium rema9$ gase\s & c\ld ?us be sep>at$4 ,krypton 0 obta9$ f ! residues left on ! evaporation ( a l>ge quantity ( liquid air4 ,mix$ ) ! krypton 0 a ?ird gase\s con/itu5t ( air1 to :i* ! "n x5on 71 ! /rang]7 0 giv54 ,! boil+-po9t ( krypton at atmosph]ic pressure 0 f\nd to be -#aeb1 & its melt+-po9t -#afi2 ! boil+-po9t ( x5on 0 -#aji & its melt+-po9t -#adj4 ,_! critical temp]atures 7 respectively -#fb4e & #ad4g4 ,h5ce x5on c\ld be liquefi$ by pressure a v little bel[ ! mean temp]ature ( ! air4 ,neon boils at -#bdc & freezes at -#bec4 ,!y =m col\rless liquids freez+ to ice-l solids4 ,all ( !m1 ) ! exception ( argon1 :i* is pres5t to ! ext5t ( ab\t #a "p 9 #ajg p>ts ( air1 are conta9$ 9 extremely small am\nts 9 ! atmosph]e1 approximately 9 ! foll[+ proportions3 ,helium #a "p 9 #bde1cjj p>ts by volume4 ,neon #a 0 0 #hj1hjj 0 0 ,krypton #a 0 0 #bj millions 0 0 ,x5on #a 0 0 #agj 0 0 0 ,_m tons ( liquefi$ air h s9ce be5 sy/ematically fractionat$1 b no o!r gas ?an ^? above nam$ has be5 obta9$4 ,julius ,?oms51 ( ,cop5hag51 9 a pap] publi%$ 9 #ahie1 entitl$ ,on ! ,probability ( ! ,exi/5ce ( a ,gr\p ( ,inactive ,elem5ts1 po9t$ out1 9 relation to ,m5deleff's ,law ( ,p]iodicity 7see ante71 t 9 p]iodic functions ! *ange f negative to positive value1 or ! rev]se1 c take place only by a passage ?r\gh z]o or ?r\gh inf9ity2 9 ! fir/ case ! *ange is gradual1 & 9 ! second case x is sudd54 ,! fir/ case corresponds ) ! gradual *ange 9 electrical "* ) ris+ atomic weight 9 ! sep>ate s]ies ( ! p]iodic sy/em1 & ! second case corresponds ) a passage f "o s]ies to ! next4 ,x !re=e appe>s t ! passage f "o s]ies to ! next 9 ! p]iodic sy/em %\ld take place ?r\gh an elem5t :i* is electrically indiff]5t4 ,! val5cy ( su* an elem5t w\ld be z]o1 & !re=e 9 ?is respect also x w\ld repres5t a transitional /age 9 ! passage f ! unival5t electronegative elem5ts ( ! sev5? to ! unival5t electropositive elem5ts ( ! fir/ gr\p4 ,?is indicates ! possible exi/5ce ( a gr\p ( inactive elem5ts ) ! atomic weights #d1 #bj1 #cf1 #hd1 #acb--numb]s correspond+ fairly closely ) ! atomic weights respectively ( helium1 neon1 argon1 krypton1 & x5on4 99 99 99 99 99 ,no discov]y ( rec5t ye>s has creat$ m widespread int]e/ ?an t ( ! radio-active elem5ts4 ,9 #ahif ,h5ri ,becqu]el f\nd t uranium salts emitt$ an invisible radiation :i* _h ! p[] ( affect+ a photographic plate1 ev5 ?\gh n directly expos$ to x1 exactly 9 ! same way z ! ,rntg5 or ,x-rays4 ,s9ce t "t a numb] ( sub/ances h be5 %[n to possess a simil> prop]ty4 ,su* sub/ances are said to be radio-active4 ,! radiation emitt$ by !m is n uni=m 9 "*4 ,x has be5 f\nd to be ( ?ree di/9ct types1 kn[n respectively z ! 1 1 & radiations4 ,! rays consi/ ( positively electrifi$ p>ticles mov+ ) a velocity equal to ab\t a fifte5? ( t ( light4 ,^! rays h little p5etrative p[]1 & are capable ( be+ deflect$ by a magnet4 ,! rays consi/ ( negatively electrifi$ p>ticles ( a mass n great] ?an "o ?\s&? ( t ( ! hydrog5 atom1 & !y move ) a velocity approximat+ to t ( light4 ,! rays h a great] p5etrative p[] ?an ! rays1 & are ev5 m readily deflect$ by a magnet4 ,! rays are analog\s to1 if n id5tical )1 ! ,x or ,rntg5 rays2 !y move ) ! velocity ( light1 h a high p5etrative p[]1 b are n affect$ by ! magnet4 ,all ?ree =ms ( radiation r5d] gases electrically conductive1 excite lum9esc5ce or fluoresc5ce 9 c]ta9 sub/ances1 *ange ! col\r ( glass1 conv]t oxyg5 into ozone & yell[ phosphorus into r$ phosphorus1 & act ^u photographic plates4 ,accord+ to ! dis9tegration !ory ( ,ru!r=d & ,soddy1 ! radio-active elem5ts are =ms ( matt] und]go+ *anges result+ 9 ! =mation ( new =ms possess+ *emical & physical prop]ties diff]+ f ^? ( ! p>5t sub/ance1 ^! *anges be+ accompani$ by ! production ( s5sible heat1 or "s o!r manife/ation ( en]gy1 due to ! process ( trans=mation ( ! *ang+ atoms4 ,! rate ( *ange is f\nd to be diff]5t = ea* radio-active elem5t1 b to be con/ant = ! same elem5t irrespective ( its p>ticul> =m ( comb9ation4 ,! relative radio-activity ( ! v>i\s *emical comb9ations ( a giv5 radio-active elem5t is directly proportional to ! quantity ( ! elem5t conta9$ 9 !m4 ,! process ( dis9tegration may be c>ri$ ?r\gh a numb] ( int]m$iate products until a /able =m is produc$4 ,uranium1 9 :i* ! ph5om5on ( radio-activity 0 fir/ p]ceiv$1 is suppos$ to give rise to no few] ?an sev5te5 diff]5t =ms ( matt]1 includ+ radium1 act9ium1 & polonium4 ,?orium1 ano!r radio-active elem5t1 is suppos$ to dis9tegrate into eight diff]5t =ms ( matt]4 ,uranium dis9tegrates ) extreme sl[ness2 x is calculat$ t 9 a ye> n m ?an "o t5-billion? "p ( ! uranium is trans=m$4 ,! fir/ dis9tegration product is t]m$ uranium x4 ,if a quantity ( dehydrat$ uranium nitrate be treat$ ) ord9>y e!r1 a slight residue is obta9$ :i* is f\nd to conta9 uranium x4 ,x emits & rays1 & is relatively rapidly trans=m$ into o!r sub/ances4 ,ord9>y uranium1 fre$ f uranium x1 only emits rays4 ,uranium salts c be fre$ f uranium x by repeat$ cry/allisation1 uranium x rema9+ 9 ! "m liquors4 ,illu/ration3 ,,m>ie ,,curie 7ne ,,sklod[ska74 ,! exi/5ce ( radium 0 fir/ made kn[n by ,mme4 ,curie 9 #ahih4 ,9 exam9+ c]ta9 uranium m9]als & uranium products1 ,mme4 ,curie obs]v$ t _! radio-activity 0 app>5tly great] ?an t correspond+ ) ! am\nt ( uranium conta9$ 9 !m1 & %e 0 l$ to surmise t ?is might be due to ! pres5ce ( "s con/itu5t m /rongly radio-active ?an uranium4 ,?is supposition prov$ to be well f\nd$1 & %e ev5tually succe$$ 9 isolat+ a new elem5t t]m$ radium1 =m+ comp\nds ) *>act]s & relation%ips ak9 to ^? ( b>ium4 ,! ri*e/ s\rce ( radium at pres5t kn[n consi/s ( c]ta9 residues occurr+ at ,joa*im/hal1 9 ,bohemia1 left aft] ! extraction ( uranium f pit*-bl5de1 9 :i* radium occurs to ! ext5t ( #j4b gram p] ton4 ,^! residues are ma9ly sulphates ( lead & calcium1 mix$ ) a great v>iety ( o!r metallic comp\nds4 ,to obta9 ! radium ! mixture is heat$ ) conc5trat$ cau/ic soda solution1 ! residue wa%$ ) wat] & treat$ ) hydro*loric acid :i* dissolves ! great] portion ( ! mat]ial4 ,ne>ly ! :ole ( ! radium is left 9 ! insoluble portion4 ,?is1 aft] wa%+ ) wat]1 is boil$ ) a solution ( sodium c>bonate s z to trans=m ! alkali-e>?s into c>bonates4 ,^! are conv]t$ into *lorides or bromides f :i*1 by repeat$ cry/allisation1 b>ium *loride or bromide is obta9$1 conta9+ ! great] portion ( ! radium z a halide salt4 ,! radium & b>ium salts are !n sep>at$ by fractional cry/allisation1 ! radium salts be+ slightly less soluble 9 wat] & alcohol1 & 9 solutions conta9+ ! halog5 acid1 ?an ! b>ium salt4 ,pure radium *loride 7,ra,cl#b7 is a :ite cry/all9e salt1 resembl+ b>ium *loride1 ) :i* x appe>s to be isomorph\s4 ,radium1 l b>ium1 =ms an insoluble c>bonate & sulphate1 b a soluble nitrate & bromide4 ,! bromide is mu* less /able ?an ! *loride2 on /&+ x evolves brom9e & becomes basic4 ,radium has z yet be5 obta9$ 9 su* small quantities t v few ( its comp\nds h be5 prep>$4 ,! rays f radium salts burn ! sk91 & are f\nd to be useful 9 ! de/ruction ( rod5t ulc]s2 !y appe> to act ^u proteids1 de/roy bact]ia1 blea* *lorophyll1 & affect ! g]m9ative p[] ( se$s4 ,a pure & fre%ly-prep>$ salt ( radium seems to emit only rays1 b x soon =ms dis9tegration products1 & !n gives out1 9 addition1 ! & rays4 ,9 ! process ( dis9tegration ! salts emit heat correspond+ to ab\t #ge gram calories p] h\r = ea* gram ( radium pres5t2 _! temp]ature is ?us uni=mly high] ?an t ( _! environm5t4 ,"o product ( ! *ange probably connect$ ) ! emission ( ! rays1 is ! gas helium4 ,radium has an atomic weight ( #bbf4e4 ,x is reg>d$ z a product ( ! dis9tegration ( uranium1 ! atomic weight ( :i* is #bch4e4 ,x is believ$ to h be5 =m$ ?r\gh an int]m$iate product kn[n z ionium1 a radio-active elem5t discov]$ by ,boltwood 9 ! m9]al c>nolite4 ,! atomic weight ( ionium is surmis$ to be ab\t #bcj4 ,radium itself is suppos$ to =m at lea/ eight dis9tegration products1 ! fir/ ( :i* is ! s-call$ emanation1 discov]$ by ,dorn 9 #aijj1 an inactive gas ) an atomic weight ( ab\t #ahj1 giv+ a bright l9e spectrum1 decompos+ into helium1 lib]at+ oxyg5 & hydrog5 f wat]1 & capable ( be+ cond5s$ to a liquid & solidifi$ at a l[ temp]ature4 ,ramsay & ,gray h det]m9$ its physical con/ants4 ,! liquid is phosphoresc5t & %9es ) a col\r dep5d+ on ! nature ( ! glass ( ! vessel :i* conta9s x4 ,! solid is also phosphoresc5t1 ! col\r v>y+ ) ! temp]ature4 ,x gives out only rays & 9 its dis9tegration1 l radium1 evolves heat4 ,its position 9 ! ,p]iodic ,table is probably above t ( x5on4 ,o!r products are kn[n z radio-lead & polonium4 ,! latt] sub/ance 0 id5tifi$ by ,m4 & ,mme4 ,curie 9 #ahih1 & 0 ! fir/ ( ! /rongly radio-active sub/ances to be recognis$4 ,9 ! p]iodic sy/em x seems to foll[ bismu? & to be a memb] ( ,gr\p ,,vi41 ) a possible atomic weight ( #baj4 ,its spectroscopic *>act]s h rec5tly be5 exam9$ by ,mme4 ,curie & ,debi]ne1 :o h %[n t 9 its decay x evolves helium4 ,! rate ( dis9tegration ( radium is relatively sl[2 x has be5 calculat$ t ! "t requir$ = half ( any giv5 quantity ( radium to *ange completely into o!r products is ab\t #bjjj ye>s4 ,ru!r=d has calculat$ t 9 #bf1jjj ye>s a kilogram ( radium w\ld be r$uc$ to "o milligram ( active sub/ance1 ! rema9d] hav+ pass$ into degradation products4 ,9 #ahii ,debi]ne ann\nc$ ! exi/5ce ( ano!r radio-active elem5t conta9$ 9 uranium m9]als1 :i* he t]m$ act9ium4 ,?is is probably a dis9tegration product ( uranium & id5tical ) ! emanium ( ,giesel4 ,x occurs associat$ ) ! r>e e>?s :i* c be sep>at$ f ! pit*-bl5de residues1 & is ev5tually f\nd 9 ! lan?anum salts4 ,no?+ is kn[n z to its atomic weight or its *emical relation%ips4 ,x und]goes *ange1 & =ms1 app>5tly1 a gase\s emanation :i* rapidly dis9tegrates & c be cond5s$ to a liquid at a l[ temp]ature4 ,f\r o!r successive products h be5 id5tifi$ by ! "* ( ! radiation !y emit1 _! degradation con/ants1 & ! "t requir$ = "o half ( any giv5 quantity to dis9tegrate into o!r =ms ( matt]4 ,?orium 0 %[n to conta9 a radio-active elem5t by ,mme4 ,curie & ,s*midt1 indep5d5tly1 9 #ahih4 ,:e!r ?orium is itself active is d\btful4 ,! rate ( dis9tegration ( radio-?orium is probably great] ?an t ( uranium4 ,x1 too1 seems to =m a gase\s emanation :i* c be cond5s$ at ! temp]ature ( liquid air & appe>s to be an in]t gas ( high molecul> weight ) ! *>act]i/ics ( ! argon family4 ,! type ( radiation emitt$ by ! sev]al products has be5 obs]v$1 & _! con/ants ( *ange & half-value p]iods calculat$2 b little or no?+ is kn[n at pres5t conc]n+ _! atomic weights1 spectroscopic or *emical *>act]s4 ,,*apt] ,,iv ,,atoms ,,& ,,molecules3 ,,atomic ,,weights ,,& ,,equival5ts ,x has already be5 po9t$ out t ! discov]y by ,gay ,lussac1 & indep5d5tly by ,dalton1 t gases comb9e 9 simple proportions by volume1 & t ! volume ( ! gase\s product1 measur$ "u comp>able conditions ( temp]ature & pressure1 /& 9 simple relation to ! volumes ( ! con/itu5ts1 seem$ to mo/ ( ,dalton's contempor>ies1 b n to ,dalton himself1 to af=d /rong evid5ce ( ! validity ( 8 explanation ( ! ess5tial nature ( *emical comb9ation4 ,x appe>$ obvi\s f ! facts t !re mu/ exi/ "s simple relation betwe5 ! d5sities1 or specific gravities1 ( ! elem5t>y gases & _! atomic weights4 ,:51 h[ev]1 ! pr9ciple und]ly+ ,gay ,lussac's law 0 ext5d$ s z to include gases 9 g5]al--bo? simple & comp\nd--difficulties 7 met ) :i* 7 only satisfactorily cle>$ away dur+ ! latt] half ( ! n9ete5? c5tury4 ,! fir/ rational attempt to expla9 ! facts obs]v$ by ,dalton & ,gay ,lussac1 conc]n+ ! volumetric relations ( gases1 0 made 9 #ahac by ,am$eo ,avogadro by ! assumption t a giv5 volume ( all gases--simple or comp\nd--conta9s ! same numb] ( integral molecules2 h5ce ! relative weights ( ^! volumes repres5t ! relative weights ( ! molecules4 ,accord+ to ,avogadro1 9 ! case ( ! simple gases ! integral molecules are compos$ ( a c]ta9 numb] ( elem5t>y molecules ( ! same k9d1 :]eas ! integral molecules ( comp\nd gases & vap\rs are made up ( elem5t>y molecules ( diff]5t k9ds4 ,! elem5t>y molecule ( ,avogadro is n[ t]m$ ! atom2 8 integral molecule we call simply a molecule4 ,simil> conceptions 7 publi%$ indep5d5tly by ,ampre 9 #ahad4 ,x foll[s f ! doctr9e ( ,avogadro & ,ampre t1 z ! numb] ( integral molecules is ! same 9 equal volumes ( all gases1 ^! molecules mu/ be equidi/ant f ea* o!r1 _! mutual di/ances dep5d+ ^u pressure & temp]ature4 ,?is at once s]ves to expla9 ! laws ( ,boyle & ,dalton t gases1 no matt] :at _! *emical nature1 behave id5tically1 z reg>ds *ange ( volume1 :5 compress$ by pressure or exp&$ by heat4 ,! true significance ( ! hypo!ses ( ,avogadro & ,ampre 0 long obscur$1 fir/ on acc\nt ( _! imp]fect appreciation by ! great lead]s ( *emical ?\ght dur+ ! fir/ half ( ! n9ete5? c5tury--,b]zelius1 ,gay ,lussac1 ,wolla/on1 & ,gmel9--&1 secondly1 on acc\nt ( ! almo/ univ]sal practice ( d$uc+ atomic weights f purely *emical consid]ations ( equival5ce4 ,at ! same "t1 x mu/ be admitt$ t ! recognition ( ! value ( ^! hypo!ses 0 /ill fur!r ret>d$ by ! seem+ anomalies :i* result$ f a m ext5d$ k ( ! vap\r d5sities ( elem5ts & comp\nds4 ,?us ! vap\r d5sities ( m]cury1 sulphur1 phosphorus1 & ars5ic1 z asc]ta9$ by ,dumas & ,mits*]li*1 7 pla9ly inconsi/5t ) *emical analogies & ! law ( ,dulong & ,petit4 ,s1 too1 :at appe>$ to be ! vap\r d5sities ( sal-ammoniac1 phosphorus p5ta*loride1 sulphuric acid1 calomel1 & ( o!r sub/ances t might be m5tion$1 7 n 9 accordance ) ! values dem&$ by o!r well-asc]ta9$ facts4 ,by ! middle ( ! n9ete5? c5tury ! hypo!sis ( ,avogadro 0 practically =gott5 & ! law ( volumes ignor$4 ,! atomic weights ( ! elem5ts1 & ! sy/em ( notation univ]sally employ$ 9 ,engl& & ,g]many1 7 bas$ :olly ^u equival5ts4 ,! anomalies ?us creat$ 7 cle>ly po9t$ out by ,g]h>dt1 & subsequ5tly by ,laur5t :o %[$ h[ a consi/5t & h>moni\s explanation ( ! facts c\ld be rea*$ by reg>d+ z true equival5ts equal volumes--= example1 ( /eam1 ammonia1 hydrog5 *loride1 c>bon dioxide1 m>% gas1 etc42 by assum+1 9 o!r words1 t equal numb]s ( ! molecules ( ^! v>i\s sub/ances are conta9$ 9 equal volumes ( ! gases1 z cont5d$ by ,avogadro & ,ampre4 ,! simplicity & consi/5cy ( ! new notation gradually won = x ! adhesion ( *emi/s4 ,?is adhesion 0 facilitat$ by ! memorable rese>*es ( ,williamson on e!rification1 ( ,g]h>dt on ! anhydrides1 & by ! "w ( ,frankl& on ! radicals2 & x rea*$ its logical conclusion :5 ,cannizz>o--on ! basis ( ,avogadro's hypo!sis--discuss$1 9 #aheh1 ! true atomic weights ( ! metallic elem5ts z di/+ui%$ f _! equival5t values4 ,9 c]ta9 ( its aspects ! new table ( atomic weights drawn up by ,cannizz>o resembl$ t orig9ally propos$ by ,b]zelius2 b ! numb]s adopt$ by ! ,sw$i% *emi/ 7 f\nd$ on no uni=m or rational basis1 & 7 frequ5tly inconsi/5t4 ,illu/ration3 ,,/anislao ,,cannizz>o4 ,our pres5t tables ( atomic weight br+1 !re=e1 ! values = ! sev]al elem5ts into h>mony ) ! doctr9e ( ,avogadro & ,ampre1 ) ! law ( ,dulong & ,petit1 & ) ! facts ( isomorphism4 ,! values are1 9 fact1 9 unison ) all ! crit]ia :i* s]ve to indicate ! atomic weights ( ! elem5ts4 ,z a result1 our pres5t sy/em ( notation1 :i* is1 ( c\rse1 bas$ ^u ^! atomic weights1 assigns =mul to comp\nds :i* indicate _! true relative molecul> weights & simplify ! accurate expression ( _! relation%ips & *emical trans=mations4 ,"o by "o ! in/ances ( anomal\s vap\r d5sity1 :i* 7 s _m /umbl+ blocks to ! univ]sal acceptance ( a sy/em bas$ ^u ! law ( gase\s volumes1 h be5 %[n to be n only n inconsi/5t ) x1 b actually s _m corroborative pro(s4 ,?us1 9 ! case ( ammonium *loride1 ! obs]v$ vap\r d5sity ( :i* 0 f\nd to be practically half its calculat$ value1 x has be5 prov$ t ! vap\r ( ?is salt1 :5 heat$ to ! temp]ature at :i* ! obs]vations 7 made1 is ma9ly resolv$ into molecules ( ammonia & hydrog5 *loride1 :i* toge!r occupy d\ble ! space ( ! ammonium *loride molecule4 ,phosphorus p5ta*loride vap\r1 on be+ suffici5tly heat$1 is simil>ly m or less resolv$ into phosphorus tri*loride & *lor9e4 ,moreov]1 x has be5 f\nd1 by a m accurate /udy ( ! action ( heat ^u ! vap\r ( ammonium *loride & ( phosphorus p5ta*loride1 t )9 c]ta9 n>r[ limits ( temp]ature ^! sub/ances c actually exi/ z su* 9 ! gase\s /ate1 & t ! d5sity ( _! vap\rs does actually con=m to t dem&$ by !ory4 ,moreov]1 phosphorus p5tafluoride1 ! analogue ( ! p5ta*loride1 is gase\s at ord9>y temp]atures1 & has a normal d5sity4 ,x may be heat$ to a high temp]ature )\t %[+ any sign ( decomposition4 ,limitations ( space w n all[ ( a full] explanation ( ! app>5t anomalies already allud$ to4 ,!y h ea* 9 turn be5 exp]im5tally attack$ & satisfactorily expla9$4 ,no valid exception is n[ kn[n to ! univ]sal applicability ( ! pr9ciple4 ,to-day ! *emical hi/ory ( a sub/ance1 :e!r elem5t>y or comp\nd1 if vaporisable1 is n complete until its vap\r d5sity is kn[n1 s9ce a k ( ?is con/ant af=ds ! mo/ c]ta9 means ( e/abli%+ ! relative weight ( its molecule4 ,accord+ly _m *emi/s h endeav\r$ to simplify & r5d] m conv5i5t ! modes ( det]m9+ vap\r d5sities4 ,?anks to ! ef=ts ( ,h(mann & ,victor ,mey]1 ! processes associat$ ) ! names ( ,dumas1 ,gay ,lussac1 ,deville1 & ,troo/1 :i* h furni%$ u ) valuable in=mation 9 ! pa/1 h n[ giv5 way to comp>atively simple & rapid me?ods1 :i*1 al?\gh n necess>ily m accurate1 furni% ! requir$ in=mation ) less exp5diture ( "t & tr\ble2 t is to say1 !y s]ve to indicate :i* ( two1 or m1 presum$ molecul> weights is correct1 & s enable u to e/abli% ! molecul> =mula ( ! sub/ance4 ,! *emical =mula ( a sub/ance is a cond5s$ expression ( a numb] ( facts connect$ ) its hi/ory4 ,?us ! expression ,h#b,o--! *emical =mula = wat]--indicates t ! sub/ance is compos$ ( hydrog5 & oxyg51 9 ! proportion1 us+ r\nd numb]s1 ( #b p>ts by weight ( hydrog5 & #af p>ts by weight ( oxyg52 or1 9 o!r words1 ( #b atoms ( hydrog51 ea* weigh+ #a1 & #a atom ( oxyg5 weigh+ #af4 ,! =mula1 moreov]1 connotes ! fact t :5 ! gases comb9e #b volumes ( hydrog5 unite ) #a volume ( oxyg5 to =m #b volumes ( wat]-vap\r 7/eam74 ,s1 too1 ! =mula ,h,cl--:i* repres5ts hydrog5 *loride--means t ! sub/ance is a comp\nd ( #a atom ( hydrog5 weigh+ #a unit$ ) #a atom ( *lor9e weigh+ #ce4e2 x also d5otes ! fact t 9 ! act ( union #a volume ( hydrog5 comb9es ) #a volume ( *lor9e to =m #b volumes ( hydrog5 *loride4 ,la/ly1 ! =mula ,,nh#c signifies t ! molecule ( ammonia is compos$ ( #a atom ( nitrog5 weigh+ #ad1 & #c atoms ( hydrog51 ea* weigh+ #a2 x fur!r indicates t :5 ammonia gas is resolv$ into its con/itu5ts1 z x c be :5 suffici5tly heat$1 #b volumes ( ammonia gas are increas$ to #d volumes ( a mixture made up ( #a volume ( nitrog5 & #c volumes ( hydrog54 ,9 %ort1 all ! =mul are :at are call$ two-volume =mul2 t is1 ! relative molecul> weights ( ! sub/ances occupy ! same volume z two relative p>ts by weight ( hydrog54 ,h5ce _! vap\r d5sities--ref]r$ to hydrog5 z unity--are ! halves respectively ( _! molecul> weights4 ,/eam is #i times1 hydrog5 *loride #ah4be times1 & ammonia #h4e times heavi] ?an hydrog51 :5 measur$ "u id5tical conditions ( temp]ature & pressure4 ,! quantities express$ by ! =mul ,h#b1 ,h#b,o1 ,h,cl1 ,,nh#c1 occupy ! same volume4 ,?is is equally true ( ! quantities express$ by ,o#b1 ,n#b1 ,cl#b1 etc4 ,^! expressions signify t ! molecules ( ! elem5ts ( hydrog51 oxyg51 nitrog51 & *lor9e consi/ ea* ( #b atoms ( ! respective sub/ances3 ! molecule ( wat] consi/s ( #c atoms--#b ( hydrog5 & #a ( oxyg52 ! molecule ( hydrog5 *loride ( #b atoms--#a ( hydrog5 & #a ( *lor9e2 :]eas ! molecule ( ammonia conta9s #d atoms--#a atom ( nitrog5 & #c atoms ( hydrog54 ,c]ta9 ( ! elem5t>y bodies are1 z already /at$1 capable ( exi/+ 9 diff]5t allotropic /ates4 ,?us !re is a modification ( oxyg5 kn[n z ozone4 ,?is sub/ance has long be5 recognis$ z be+ =m$ f air "u ! influ5ce ( ! electric dis*>ge4 ,x 0 ! subject ( /udy by ,s*nbe9 z f> back z #ahci2 b t x 0 a cond5s$ =m ( oxyg5 & n a p]oxide ( hydrog5--z 0 at "o "t surmis$--0 fir/ e/abli%$ by ,&rews & ,tait4 ,! degree ( its cond5sation 0 def9itely asc]ta9$ by ,soret by obs]v+ its rate ( diffusion1 f :i*1 on ! basis ( ,graham's law1 its d5sity c\ld be inf]r$4 ,x 0 f\nd to be #a times t ( ord9>y oxyg54 ,h5ce1 if ! molecule ( oxyg5 consi/s ( #b atoms1 t ( ozone consi/s ( #c atoms4 ,! *emical symbol ( ozone is1 !re=e1 ,o#c4 ,x has be5 f\nd also t ! molecule ( sulphur1 9 ! /ate ( solution1 conta9s eight atoms4 ,?is complex molecule 9 ! gase\s /ate gradually breaks d[n z ! temp]ature is increas$1 & at temp]atures above #hej conta9s1 l its analogue oxyg51 only two atoms4 ,! molecules ( phosphorus & ars5ic1 9 ! gase\s /ate1 are ea* f\nd to consi/ ( f\r atoms4 ,on ! o!r h&1 ! molecules ( m]cury1 z9c1 & cadmium ea* consi/ ( only "o atom4 ,z w be %[n lat]1 ,kundt & ,w>burg e/abli%$1 9 #ahge1 ! fact t m]cury vap\r is a monatomic gas1 by det]m9+ ! rate at :i* s\nd is propagat$ ?r\gh x4 ,9 ! same way x 0 %[n t helium1 argon1 & its cong5]s are also1 z already /at$1 monatomic gases4 ,! applicability ( ! law ( ,dulong & ,petit to ! det]m9ation ( atomic weights has be5 frequ5tly exemplifi$ dur+ ! la/ sixty ye>s2 & a numb] ( ^! con/ants h be5 rectifi$ by its means--e4g41 ( ?allium1 uranium1 gluc9um1 indium1 etc4 ,! anomalies pres5t$ by ! cases ( elem5ts ( l[ atomic weight--e4g41 c>bon1 boron1 silicon--h be5 fur!r inquir$ into2 & x has be5 %[n by ,web]1 & indep5d5tly by ,dew>1 t 9 ! case ( ^! sub/ances ! specific heat rapidly increases ) ! temp]ature1 & approximates at high temp]atures to a value requir$ by ! law ( ,dulong & ,petit4 ,)9 rec5t ye>s o!r me?ods ( asc]ta9+ molecul> weights h be5 put at ! disposal ( *emi/s4 ,^! me?ods are especially valuable 9 ! case ( bodies :i* _c be volatilis$4 ,!y dep5d ^u ! influ5ce ( ! sub/ance 7#a7 ^u ! freez+-po9t & 7#b7 ^u ! boil+-po9t ( a solv5t4 ,x has long be5 kn[n t a sub/ance 9 solution affects ! freez+-po9t ( ! solv5t1 & 9 ! great majority ( cases depresses x4 ,sir ,*>les ,blagd51 z f> back z #aghh1 %[$ t 9 aque\s solutions ( inorganic salts ! depression 0 proportional to ! am\nt dissolv$4 ,x 0 subsequ5tly f\nd by ,coppet t1 9 a numb] ( solutions ( simil> salts :]e ^! 7 pres5t 9 ! ratio ( _! molecul> weights1 ! solutions froze at practically ! same temp]ature3 ! molecul> depressions ( ! freez+-po9ts diff] f gr\p to gr\p b are ne>ly equal 9 gr\ps ( simil> comp\nds4 ,ra\lt fur!r obs]v$ t1 :5 c]ta9 quantities ( ! same sub/ance are successively dissolv$ 9 a solv5t on :i* x ex]ts no *emical action1 !re is a progressive l[]+ ( ! po9t ( solidification ( ! solution1 & ?is depression is proportional to ! weight ( ! sub/ance dissolv$ 9 a con/ant weight ( ! solv5t4 ,9 ! case ( a l>ge numb] ( solv5ts ! depressions ( ! freez+-po9t1 calculat$ = am\nts proportional to ! molecul> weights ( ! dissolv$ sub/ance1 7 ne>ly con/ant4 ,ra\lt po9t$ out t ^! relations betwe5 ! molecul> weights & ! l[]+ 9 ! freez+-po9t may be employ$ to det]m9e ! molecul> weight ( a soluble sub/ance4 ,! molecul> weight m is f\nd f ! expression m ,k_/,a1 :]e ,a is ! quoti5t obta9$ by divid+ ! obs]v$ depression 9 ! freez+-po9t ( ! solv5t by ! p]c5tage cont5t ( ! solution1 & ,k 7! molecul> depression7 is a con/ant dep5d5t on ! solv5t4 ,?us 9 ! case ( phosphor\s oxide x 0 f\nd t #j4fgfj gram add$ to #bj4fih grams ( b5z5e--9 :i* ! oxide is soluble )\t *ange--l[]$ ! freez+-po9t ( ! #c4af p] c5t4 b5z5e solution by #j4fh4 ,s9ce ! value ( ,k = b5z5e is #di1 we h 7#c4af #di7_/j4fh #bbg1 :i* s]ves to indicate t ,p#d,o#f is ! true molecul> =mula = phosphor\s oxide4 ,?is result is confirm$ by vap\r-d5sity obs]vations4 ,! effect ( add+ a sub/ance to a solv5t is to dim9i% ! vap\r pressure ( ! liquid4 ,h5ce1 s9ce ! boil+-po9t ( a liquid is t temp]ature at :i* ! vap\r pressure is equal to ! atmosph]ic pressure1 ! effect ( add+ ! soluble sub/ance is to raise ! boil+-po9t1 s9ce a high] temp]ature is requir$ 9 ord] t ! pressure ( ! vap\r %all equal t ( ! atmosph]e4 ,x has be5 prov$ t equal volumes ( solutions 9 ! same solv5t :i* h ! same boil+-po9t conta9 an equal numb] ( molecules ( ! dissolv$ sub/ance4 ,! equation = ! molecul> increm5t ( ! boil+-po9t = a solv5t is d #j4jb,t_/w1 9 :i* d is ! increm5t ( ! boil+-po9t caus$ by ! solution ( "o gram-molecule ( a sub/ance 9 #ajj grams ( ! solv5t1 ,t ! absolute boil+-po9t ( ! solv5t1 & w ! heat ( vaporisation ( ! solv5t = "o gram4 ,! molecul> rise ( ! boil+-po9t is !re=e indep5d5t ( ! nature ( ! dissolv$ sub/ance4 ,! molecul> weight ( ! sub/ance m is obta9$ f ! =mula m pd_/1 9 :i* p ! p]c5tage weight ( ! dissolv$ sub/ance1 d ! molecul> increm5t 9 boil+-po9t 7#j4jb,t_/w71 ! obs]v$ rise 9 boil+-po9t4 ,if ! lat5t heat ( vaporisation ( ! liquid is unkn[n1 ! value ( d may be obta9$ by prelim9>y exp]im5ts ) a sub/ance ( kn[n molecul> weight2 9 ?is case d m_/p4 ,! calculation ( ! molecul> weight m may also be made by ! =mula m ,k7s_/,l7 #ajj1 9 :i* is ! rise 9 boil+-po9t1 s ! weight ( dissolv$ sub/ance1 ,l ! weight ( solv5t1 & ,k ! molecul> boil+-po9t increm5t4 ,conv5i5t =ms ( app>atus = us+ ^! me?ods h be5 devis$ by ,beckmann1 & are n[ 9 g5]al use4 99 99 99 99 99 ,f ! "t ( ,b]zelius1 ea* successive g5]ation ( *emi/s has /riv5 to bett] ! example ( t ma/] ( det]m9ative *emi/ry 9 ! ef=t to obta9 accurate values = ! atomic weights ( ! elem5ts4 ,among ! imm$iate successors ( ,b]zelius 9 ?is "w %\ld be m5tion$ ,turn]1 ,p5ny1 ,dumas1 & ,m>ignac4 ,dumas 9 #ahei publi%$ ! results ( an ext5sive revision ( ! atomic weights ( ! elem5ts4 ,on ?is he bas$ ! f>-rea*+ g5]alisation t1 9 ! language ( ,pr\t1 8! comb9+ or atomic weights ( bodies be> c]ta9 simple relations to "o ano!r1 frequ5tly by multiple1 & consequ5tly t _m ( !m mu/ necess>ily be multiples ( "s "o unit40 ,dumas fur!r agre$ ) ,pr\t t 8!re seems to be no reason :y bodies /ill l[] 9 ! scale ?an hydrog5 7simil>ly1 h[ev]1 relat$ to "o ano!r1 z well z to ^? above hydrog57 may n exi/1 ( :i* o!r bodies may be multiples1 )\t be+ actually multiples ( ! int]m$iate hydrog540 ,! ,belgian *emi/1 ,/as1 :o _h be5 associat$ ) ,dumas 9 a classical det]m9ation ( ! atomic weight ( c>bon1 set himself to det]m9e1 ) ! highe/ degree ( precision !n possible1 ! atomic weights ( ab\t a doz5 ( ! elem5ts1 ) a view ( asc]ta9+ 7#a7 :e!r an atomic weight is a def9ite & con/ant quantity1 or :e!r1 z sugge/$ by ,m>ignac1 & subsequ5tly by ,crookes1 an atomic weight repres5ts 8a mean value ar\nd :i* ! actual weights ( ! atoms v>y )9 c]ta9 n>r[ limits02 7#b7 :e!r1 if ! atomic weights ( ! elem5ts are respectively def9ite & inv>iable1 ! numb]s are comm5surable z alleg$ by ,pr\t & ,dumas2 & 7#c7 if x %\ld turn out t ! numb]s are sev]ally fix$ & comm5surable1 :e!r ?is necess>ily indicates t ! elem5ts are built up ( a primordial matt]1 ! ( ! anci5ts1 ref]r$ to by ,pr\t 9 #ahaf4 ,/as devot$ _m ye>s to ! solution ( ^! que/ions1 work+ on a scale & ) an accuracy & manipulative skill previ\sly unapproa*$4 ,! ma9 results ( 8 lab\r appe>$ 9 #ahfe4 ,he conclud$ 7#a7 t ! atomic weights ( ! elem5ts are absolutely con/ant values1 & are n affect$ by ! nature ( ! comp\nds 9 :i* !y occur1 or ! physical conditions ( _! exi/5ce2 7#b7 t ! numb]s s obta9$ are n comm5surable3 to quote 8 own words3 8,on doit considr] la loi de ,pr\t comme une pure illusion40 ,h5ce ! elem5ts mu/1 on ! basis ( ,/as's exp]im5tal evid5ce1 be reg>d$ z 8individualits "p10 z he express$ x--ea* a primordial & unalt]able sub/ance4 ,! appe>ance ( ?is monum5tal "w1 :i* w ev] rema9 "o ( ! classics ( *emi/ry1 creat$ a great impression4 ,its effect p]si/s to ?is day4 ,x con/itut$ a model & furni%$ a /&>d :i* ea* successive work] has /riv5 to emulate1 ) ! result t atomic weights to-day are among ! be/ asc]ta9$ ( physical con/ants4 ,space w n p]mit ( any detail$ acc\nt ( ! "w done 9 connection ) atomic weights dur+ ! =ty-five ye>s :i* h elaps$ s9ce ! publication ( ,/as's memoirs2 & ! read] :o desires full] in=mation mu/ be ref]r$ to ! special treatises on ! subject1 su* z ! ,con/ants ( ,nature ( ,f4 ,w4 ,cl>ke1 or ! monographs ( ,mey] & ,seub]t1 ,beck]1 ,sebeli51 & ,van d] ,plaats4 ,ref]5ce1 h[ev]1 mu/ be made to ! det]m9ations by ,"l ,rayleigh1 ,l$uc1 ,morley1 ,noyes1 ,guye1 ,dixon1 & ,edg> ( values :i*1 l ^? ( oxyg51 hydrog51 nitrog51 silv]1 & ! halog5s1 are l>gely made use ( z fiduci>y values 9 atomic-weight "w4 ,la/ly1 x %\ld be m5tion$1 ! re-det]m9ation ( ! atomic weights ( ! elem5ts ) ! highe/ atta9able precision & by ! mo/ ref9$ & mo/ mod]n me?ods has = "s ye>s pa/ be5 a special feature ( ! "w ( ! ,h>v>d ,laboratory1 "u ! direction ( ,!odore ,ri*>ds2 & "s ( ! mo/ tru/wor?y & be/ e/abli%$ values we possess h be5 asc]ta9$ by him & 8 pupils4 ,atomic weights are ( su* fundam5tal importance t ! v>i\s nations int]e/$ 9 ! pursuit ( *emi/ry h cons5t$ to ! e/abli%m5t ( an ,int]national ,committee1 :i* w take cognisance ( ! "w done f "t to "t 9 ?is dep>tm5t ( op]ative *emi/ry1 exam9e & assess its value1 & draw up an annual report on ! subject4 ,despite ! accumulat$ te/imony ( ?is "w 9 relation to ! validity ( ! law ( ! cons]vation ( mass1 ! suffici5cy ( ! evid5ce has n[ & aga9 be5 impugn$4 ,?is aspect ( ! matt] has )9 rec5t ye>s be5 directly inve/igat$ by ,l&olt2 & z ! result ( a pa9/ak+ s]ies ( exp]im5ts1 9 :i* e recognis$ s\rce ( error 0 remov$ or all[$ =1 x w\ld appe> t !re is absolutely no gr\nd = ! belief t !re is any dissipation ( mass 9 ! c\rse (1 or z ! result (1 a *emical *ange4 ,,*apt] ,v ,,! ,,molecul> ,,!ory ,,( ,,gases ,! m obvi\s physical ph5om5a ( gases 71 ( c\rse1 well kn[n by ! middle ( ! n9ete5? c5tury2 & ! s-call$ gase\s laws--! laws ( ,boyle1 ,dalton1 & ,gay ,lussac--7 univ]sally accept$ by *emi/s & physici/s at t "t z fundam5tal4 ,t ! fir/ two laws 7 only approximations to tru? 9 a ma!matical s5se 0 also well kn[n2 & ! exp]im5tal lab\rs ( ,regnault & ,magnus _h n only e/abli%$ limits )9 :i* !y 7 inexact1 b _h1 to "s ext5t1 indicat$ ! cause ( _! dep>ture f ! ideal condition4 ,! hypo!sis ( ,avogadro1 z already /at$1 0 practically ignor$ at ?is p]iod1 or at lea/ its value 0 unappreciat$ until ! "t ( ,g]h>dt & ,laur5t1 & m p>ticul>ly ,cannizz>o1 :o 9 #aheh po9t$ out its real mean+ & made x ! key/one 9 ! edifice ( mod]n *emi/ry4 ,"o ( ! mo/ significant a*ievem5ts ( ! la/ half-c5tury has be5 ! demon/ration t ^! gase\s laws are int]dep5d5t4 ,_! fur!r /udy1 & 9 p>ticul> ! /udy ( _! v>iation f exact ma!matical expression1 has l$ to a conception ( ! real nature ( a gas :i* n only compreh5ds & knits toge!r ^! laws1 b af=ds a rational explanation ( !m4 ,if ! laws ( ,boyle & ,dalton conc]n+ ! relations betwe5 pressure1 temp]ature1 & gase\s volume are1 & mu/ be f ! v nature ( ! case1 only approximations1 x foll[s t ! same is equally true ( ! laws ( ,gay ,lussac & ,avogadro1 s9ce ^! are dep5d5t on ! o!rs4 ,! def9ite exp]im5tal pro( t gases d n actually comb9e 9 ! precise ratios dem&$ by ! law ( ,gay ,lussac has be5 =?com+ only dur+ ! la/ tw5ty ye>s4 ,x has be5 f\nd t1 in/ead ( oxyg5 & hydrog5 comb9+ 9 ! exact ratio ( "o volume ( oxyg5 to two volumes ( hydrog5 to =m wat]1 z /at$ by ,gay ,lussac1 "o volume ( oxyg5 comb9es )1 accord+ to ,scott1 #b4jjbde vols42 accord+ to ,l$uc1 #b4jjbd vols42 accord+ to ,morley1 #b4jjbfh vols4 ( hydrog54 ,:at is true ( ! volume-ratios 9 :i* oxyg5 & hydrog5 are actually f\nd to comb9e1 "u ord9>y conditions1 is no d\bt equally true ( analog\s in/ances1 su* z ! union ( hydrog5 & *lor9e to =m hydrog5 *loride4 ,x foll[s also t ! ext5t ( ! v>iation f ! ma!matical expression ( ,gay ,lussac's law mu/ get small] & small] z ! comb9+ gases approa* ! condition ( ! ideal gas--z !y d1 = example1 "u v l[ pressures4 ,! precise degree ( dep>ture f ,gay ,lussac's law is !re=e 9 a s5se accid5tal1 & is dep5d5t ^u ! conditions "u :i* comb9ation takes place4 ,! m exact /udy ( ! physical ph5om5a ( gases1 & 9 p>ticul> ! cle>] recognition ( ! causes :i* det]m9e ! ext5t ( _! dep>ture f ! ideal gase\s laws1 h af=d$ valuable assi/ance 9 asc]ta9+ ! atomic weights ( c]ta9 elem5ts indep5d5tly ( *emical consid]ations4 ,! processes ( physical measurem5t h be5 s ref9$ )9 rec5t ye>s t physical me?ods ( arriv+ at molecul>--&1 inf]5tially1 at atomic--weights1 9 ! case ( all elem5ts & comp\nds :i* c be br\ght into a condition approa*+ t ( ! ideal gas1 are to be pref]r$ to ! gravimetric me?ods ( analysis or syn!sis z af=d+ ! mo/ probable values ( ! true atomic weights ( ! elem5ts4 ,! "w ( ,"l ,rayleigh1 ,l$uc1 & ( ,guye & 8 pupils on ! d5sities ( ! gases has furni%$ u ) a s]ies ( values = ! atomic weights ( a numb] ( ! elem5ts :i*1 9 po9t ( accuracy1 are z sup]ior to ! values ( ,/as z ! values ( ,/as 7 sup]ior to ^? ( 8 pr$ecessors4 ,daniel ,b]!lot po9t$ out 9 #ahih t ! true molecul> weight ( a gas c be d$uc$ f its d5sity & its obs]v$ v>iations f ,boyle's law "u atmosph]ic pressure & at v l[ pressures4 ,incid5tally1 ! /udy ( gase\s ph5om5a has s]v$ to place ! !ory ( atoms ^u a f> m /able f\ndation ?an x occupi$ half a c5tury ago4 ,h[ halt+ 0 ! adhesion :i* ev5 "s ( ! mo/ em95t *emi/s !n gave to ?is !ory 0 well exemplifi$ by ! rem>kable lecture giv5 be=e ! ,*emical ,society ( ,london 9 #ahfi1 9 :i* ,williamson--"o ( ! mo/ /urdy *ampions ( ,dalton's doctr9e--set =? its true value4 ,t a gas may be look$ ^u z an association ( p>ticles--h>d ela/ic sph]es--mov+ backw>ds & =w>ds 9 "r l9es ) great velocity1 & possess+ 9 ! aggregate a v small proportion ( ! space ?r\gh :i* !y travel1 0 fir/ conceiv$ by ,daniel ,b]n\lli 9 #agch4 ,by means ( ?is hypo!sis he expla9$ ! direct proportionality betwe5 ! d5sity & pressure ( a gas4 ,if ! gas consi/s ( mov+ p>ticles1 & ! pressure :i* x ex]ts on ! sides ( ! conta9+ vessel is due to ! impacts ( ^! p>ticles1 x is obvi\s t by halv+ ! orig9al volume ( ! conta9+ space we halve ! space ?r\gh :i* ! p>ticles travel1 & !re=e d\ble ! numb] ( _! impacts 9 a giv5 "t2 9 o!r words1 by compress+ ! gas to half its initial volume we d\ble ! pressure x ex]ts1 :i* is no?+ else ?an ! law ( ,boyle4 ,?is conception ( ! nature ( a gas is kn[n z ! k9etic !ory ( gases2 x 0 fur!r develop$ by ,wat]/on 9 #ahde1 /ill m fully by ,clausius 9 #aheg1 & 0 subsequ5tly plac$ 9 its pres5t position by ,maxwell & ,boltzmann4 ,t gases actually d move1 & at rates dep5d+ on _! specific nature1 0 r5d]$ probable--ap>t f ?is explanation ( ,boyle's law--by _m ph5om5a obs]v$ by *emi/s & physici/s 9 ! eighte5? & e>ly "p ( ! n9ete5? c5tury4 ,x 0 kn[n f ! obs]vations ( ,leslie 9 #ahjd t specifically light gases mov$ or diffus$ fa/] ?an heavy gases4 ,attempts to det]m9e ^! rates 7 made by ,s*midt 9 #ahbj1 & by ,graham 9 #ahdf1 bo? ( :om f\nd t ! rate ( movem5t ( a gas 0 indep5d5t ( its *emical nature1 & 0 det]m9$ solely by its mass3 gases move at rates inv]sely proportional to ! squ>e roots ( _! d5sities4 ,! foll[+ table giv5 by ,graham %[s ! exp]im5tally asc]ta9$ relative rates = a numb] ( gases comp>$ ) ! rates dem&$ by ! 8law ( gase\s diffusion40 ,column "o gives ! "n ( ! gas2 column two1 ! obs]v$ rate ( diffusion2 & column ?ree1 ! squ>e root ( ! d5sity ( ! gas 7air #a73 ,gas4 ,"t ( diffusion4 d5sity4 ,air #a #a ,hydrog5 #j4bgf #j4bfc ,m>% gas #j4gec #j4gde ,e?yl5e #j4ihg #j4ihe ,nitrog5 #j4ihf #j4ihf ,oxyg5 #a4jec #a4jea ,c>bon dioxide #a4bjc #a4bcg ,nitrog5 & e?yl5e are1 *emically1 totally dissimil> gases1 b !y h ! same d5sity & h5ce ! same rate ( movem5t4 ,z ,graham %[$1 x is possible to sep>ate m or less completely a mixture ( gases1 if ! con/itu5ts are ( diff]5t d5sities1 by tak+ advantage ( _! diff]5t rates ( movem5t4 ,su* an atmolytic me?od 0 employ$ by ,rayleigh & ,ramsay to prove t atmosph]ic nitrog5 conta9$ argon4 ,! fact t all gase\s sub/ances1 h[ev] diff]5t _! *emical nature1 con=m 9 ! ma9 to c]ta9 simple 8laws0 indicates ! probability t _! me*anical /ructure is simil> & comp>atively simple4 ,! s-call$ gase\s 8laws0--! laws ( ,boyle1 ,dalton1 ,gay ,lussac1 ,avogadro1 & ,graham--are to-day expla9$ on ! assumption t a gas consi/s ( an aggregation ( molecules1 mov+ incessantly 9 /raight l9es & ) great rapidity4 ,! rate ( movem5t ( ! p>ticles is v>iable by reason ( _! mutual enc\nt]s2 at ! same in/ant "s are mov+ rapidly1 o!rs m sl[ly4 ,z already expla9$1 to ?is ceaseless movem5t ( ! molecules is to be ascrib$ ! pressure !y ex]t2 ! pressure :i* a gas ex]ts on any conta9+ surface is ! aggregate effect ( ! impact ( its molecules4 ,! law ( ,boyle /ates t ! product ( ! volume ,v & pressure ,p ( a giv5 mass ( gas is inv>iable s long z ! temp]ature is un*ang$3 ,,pv con/ant4 ,x 0 f\nd by ,regnault1 ,magnus1 ,natt]]1 & ,amagat t all gases1 ) ! exception ( hydrog51 %[ a dep>ture f ,boyle's law 9 ! s5se t ,,pv is less ?an !ory dem&s4 ,9 ! case ( hydrog5 ,,pv is great] ?an !ory4 ,?is exception1 h[ev]1 is only app>5t4 ,e gas1 if ma9ta9$ above a c]ta9 temp]ature1 %[s1 aft] a c]ta9 pressure has be5 rea*$1 a deviation 9 ! same s5se z t exhibit$ by hydrog54 ,! deviations f ,boyle's law are probably due to two causes3 7#a7 to ! effect ( cohesion among ! molecules1 :]eby ! volume1 & h5ce ,,pv1 is less ?an !ory requires2 7#b7 ! molecules are n ma!matical po9ts--!y h a c]ta9 volume2 h5ce1 ) increas+ pressure1 ,,pv is great] ?an !ory dem&s4 ,! effect ( ! molecule hav+ a c]ta9 magnitude w be cle> f ! foll[+ figure3 ,let ,m be a molecule mov+ backw>ds & =w>ds )9 a c]ta9 space1 a b3 ,m a b ,assume1 n[1 we halve ! conta9+ space3 ,m a b ,x w be se5 t ,m1 s9ce its volume is un*ang$1 w h less ?an half ! orig9al di/ance to travel or1 9 o!r words1 x w /rike ! b\nd>ies ( ! conta9+ space m ?an twice z frequ5tly 9 ! same int]val ( "t z be=e2 h5ce ,p1 & !re=e ,,pv1 becomes great] ?an ,boyle's law dem&s4 ,x w be notic$1 !n1 t ! two causes t5d+ to br+ ab\t deviations f ,boyle's law act 9 contr>y directions4 ,9 ! great] numb] ( gases ! effect due to cohesion at ord9>y pressure is great] ?an ! effect due to ! actual space occupi$ by ! molecules4 ,9 ! case ( hydrog5 at ord9>y temp]ature ! contr>y is ! case2 if1 h[ev]1 hydrog5 is /rongly cool$1 x %[s v>iations simil> to ^? exhibit$ by o!r gases at ord9>y temp]atures4 ,by heat+ ^! gases ! effect due to cohesion--to ! mutual attraction ( ! molecules--becomes less & less2 9 su* circum/ances ^! gases %[ dep>tures f !ory 9 ! same s5se t hydrog5 does at ord9>y temp]atures4 ,! effect ( mutual attraction among ! molecules is to make ! volume ( ! gas less ?an ! !oretical value2 ! cohesive =ce may !re=e be reg>d$ z equal 9 effect to a c]ta9 additional pressure2 t is1 7,p ,a7 ,v con/ant1 9 :i* ,a is ! measure ( ! =ce ( cohesion4 ,a1 ( c\rse1 mu/ h relation to ! numb] ( molecules mutually attract$3 ,a is proportional to ! squ>e ( ! numb] ( ! molecules4 ,b ! numb] ( ! molecules 9 ! unit volume is proportional to ! d5sity ( ! gas1 & 9 a giv5 mass ( gas ! d5sity is inv]sely proportional to ! volume4 ,h5ce ,a is inv]sely proportional to ! squ>e ( ! volume--,a a_/,v#b1 h5ce 7,p a_/,v#b7 ,v con/ant4 ,n[ let u trace ! effect ( ! second cause ( v>iation f ! ma!matical exactitude ( ,boyle's law4 ,! fact t ! molecules are n ma!matical po9ts means t ,v 9 ! =ego+ expression is n id5tical ) ! space 9 :i* ! molecules move4 ,t space is ,v - b1 9 :i* b is ! measure ( ! aggregate volume ( ! molecules4 ,h5ce ! true expression becomes 7,p a_/,v#b7 7,v - b7 con/ant4 ,! law ( ,dalton 7,*>les7 also receives its simple/ explanation by ! k9etic !ory ( gases2 &1 moreov]1 ! dep>tures f ! ma!matical tru? ( ! /atem5t foll[ z a necess>y consequ5ce ( ! facts t ! molecules h s5sible magnitudes & are mutually attract$4 ,we c measure ! effect ( heat ^u a gas 9 two ways4 ,we c ei!r keep ! pressure ( ! gas con/ant1 & measure ! increase 9 volume2 or we c prev5t ! gas f exp&+1 & measure ! ela/ic =ce or pressure x ex]ts4 ,if ! law ( ,dalton 7 ma!matically true1 x w\ld foll[ t1 if ! volume ( ! gas 7 ma9ta9$ con/ant dur+ ! heat+1 its pressure w\ld increase 9 ! same proportion z ! volume w\ld h increas$ if ! gas _h be5 all[$ to exp&1 b ma9ta9$ at a con/ant pressure4 ,9 o!r words1 ! expansion-coeffici5t & ! pressure-coeffici5t %\ld be ! same4 ,exp]im5t %[s1 h[ev]1 t !y are n id5tical4 ,! foll[+ table gives ! results ( a numb] ( measurem5ts by ,regnault3 ,expansion ,pressure 7,pressure 7,volume ,con/ant74 ,con/ant74 ,hydrog5 4#jjcffa 4#jjcffg ,air 4#jjcfgj 4#jjcffe ,c>bon dioxide 4#jjcgaj 4#jjcfhh ,sulphur dioxide 4#jjcijc 4#jjchde ,v>iations 9 ! same s5se h s9ce be5 obs]v$ by ,jolly & ,*appuis4 ,) ! exception ( hydrog51 & probably also helium1 all ! gases %[ great] values = ! coeffici5t ( expansion ?an = ! coeffici5t ( pressure1 & ! diff]5ces are great] ! great] ! coeffici5t ( expansion ( ! gas4 ,s9ce1 z we h already /at$1 ! law ( ,boyle is directly relat$ to ! law ( ,dalton1 bo? be+ dep5d5t on molecul> movem5ts1 ! same c\rse ( reason+ us$ to acc\nt = ! v>iations 9 ! case ( ,boyle's law applies equally to ! case ( ,dalton's law4 ,! 8law0 ( ,avogadro foll[s also z a necess>y consequ5ce ( ?is explanation ( ! laws ( gase\s pressure & temp]ature4 ,if all gases %[ approximately ! same increase 9 pressure :5 heat$ "u con/ant volume1 & if ! increas$ pressure is due only to ! increas$ en]gy ) :i* ! molecules /rike ! sides ( ! conta9+ vessel1 x foll[s t all gases mu/ conta9 ! same numb] ( molecules 9 unit volume4 ,b z1 f ! v nature ( ! case1 ! laws ( ,boyle & ,dalton _c be ma!matically true1 x foll[s t ! laws ( ,avogadro & ,gay ,lussac mu/ be only approximations 9 ! same s5se4 ,! law ( ,graham1 connect+ ! rate ( diffusion ( a gas ) its d5sity1 foll[s also z a necess>y consequ5ce ( ?is explanation ( ! laws ( ,boyle1 ,dalton1 ,gay ,lussac1 & ,avogadro4 ,if ! numb] ( molecules 9 ! unit volume ( any gas1 :atev] be its nature & :atev] be _! mass1 is approximately ! same1 x foll[s t ! mean velocity ( ! molecules mu/ be v>iable2 _! mean velocities mu/ be 9 ! inv]se ratio ( ! squ>e roots ( _! d5sities4 ,! mean velocity ) :i* ! molecules ( a gas move c be calculat$ if we "k ! pressure x ex]ts1 ! weight ( a def9ite volume1 & ! value ( ! accel]ation due to gravity4 ,! squ>e ( ?is velocity 9 metres p] second ( "t at #j;,c4 is giv5 by ! expression ,u #cpg_/q 9 :i* p pressure p] squ>e metre #aj1ccc kilograms2 g ! gravitation con/ant #i4ha2 q weight ( a cubic metre ( ! gas at #j;,c4 & "o atmosph]e ( pressure4 ,= hydrog5 we h ,u #c #aj1ccc #i4ha_/j4jhii :5ce ,u #ahdb metres p] second2 = oxyg5 we h ,u #c #aj1ccc #i4ha_/a4dcj1 :5ce ,u #dfa4 ,^! numb]s accord ) ^? dem&$ by ,graham's law4 ,! d5sity ( ,h be+ tak5 z #a1 t ( oxyg5 is #af & #af #d2 ! numb]s #ahdb & #dfa are 9 ! ratio ( #d to #a4 ,! am\nt ( heat requir$ to raise ! temp]ature ( ! unit mass ( a gas ?r\gh a def9ite int]val dep5ds1 z ,laplace fir/ po9t$ out1 ^u :e!r ! gas is all[$ to exp& or n2 9 o!r words1 ! specific heat ( a gas v>ies z ! heat+ is at con/ant volume or at con/ant pressure4 ,if1 hav+ rais$ ! temp]ature ( ! unit mass1 & s exp&$ x1 we !n compress x until x occupies its initial volume1 a fur!r rise ( temp]ature takes place )\t any ext]nal heat hav+ be5 appli$4 ,?is rise ( temp]ature is1 9 fact1 due to ! lib]ation ( ! am\nt ( heat requir$ m]ely to exp& ! gas )\t increas+ its temp]ature4 ,! quantity ( heat ne$$ to raise ! temp]ature ( a gas ?r\gh a def9ite int]val is !re=e great] :5 x is all[$ to exp& ?an :5 its volume is kept con/ant2 9 o!r words1 ! specific heat at con/ant pressure is great] ?an ! specific heat at con/ant volume4 ,! ratio ( ! two specific heats c be calculat$3 on ! assumption t ! en]gy imp>t$ to ! molecules simply accel]ates _! mean rectil9e> velocity1 & t no en]gy is absorb$ 9 do+ int]nal "w among !m1 x is f\nd t1 :5 ! gas is p]mitt$ to exp&1 ! am\nt ( heat requir$ is #a4fg times great] ?an t ne$$ :5 its volume is kept con/ant4 ,?is ratio has be5 exp]im5tally det]m9$ = a numb] ( gases4 ,= oxyg5 "u normal conditions x is #a4djh1 = hydrog5 #a4dad1 = c>bon dioxide #a4bfd1 = me?ane #a4bfi--;all numb]s notably bel[ ! value #a4fg4 ,! direct exp]im5tal det]m9ation ( ?is ratio by !rmometric measurem5ts is a matt] ( "s difficulty4 ,x 01 h[ev]1 demon/rat$ by ,dulong t x c be asc]ta9$ ) comp>ative ease f obs]vations on ! velocity ( s\nd 9 ! gas--! velocity be+ probably a direct function ( ?is ratio4 ,z c>ri$ out exp]im5tally1 ! me?od consi/s 9 s5d+ a s\nd-wave ?r\gh ! gas conta9$ 9 a glass tube along ! horizontal l5g? ( :i* is /rewn a quantity ( a light p[d] su* z ! spores ( lycopodium or f9ely divid$ silica4 ,! glass tube is fitt$ at "o end ) a glass rod2 by rubb+ ?is a s]ies ( longitud9al vibrations is set up & communicat$ to ! gas :]eby ! light p[d] is ?r[n up into little heaps along ! tube1 ! di/ance betwe5 ! heaps be+ equal to half a wave l5g?4 ,by comp>ative measurem5ts ) air & ! gas "u exam9ation1 data are obta9$ f :i* ! ratio ( ! specific heats c be d$uc$4 ,by exp]im5ts conduct$ on ?is pr9ciple ,kundt & ,w>burg f\nd t m]cury vap\r gave numb]s agree+ ) ! !oretical ratio #a4fg4 ,n[1 its vap\r d5sity %[s t m]cury vap\r is a monatomic gas2 x actually fulfils ! conditions prescrib$ = a gas :i* !ory indicates %\ld give ! value #a4fg4 ,all ! en]gy imp>t$ to its molecules on heat+ simply accel]ates _! translational velocity4 ,on ! o!r h&1 all ! gases above nam$ z giv+ values bel[ #a4fg are diatomic gases2 9 _! case ! en]gy imp>t$ to !m is employ$ p>tly 9 augm5t+ ! translational velocity ( ! molecules1 & p>tly 9 br++ ab\t int]nal *anges )9 !m4 ,by exp]im5ts made 9 l mann] ,ramsay & ,trav]s succe$$ 9 %[+ t ! in]t gases ( ! atmosph]e are monatomic4 ,no attempt c be made "h to expla9 ! v>i\s me?ods by :i* x has be5 s\ght to obta9 an e/imate ( ! absolute size ( gase\s molecules or to det]m9e _! numb] 9 a def9ite volume4 ,by obs]vations on _! viscosity1 rates ( diffusion1 conductivity = heat1 v>iations f ! law ( ,boyle1 dielectric con/ants1 electric *>ges1 etc41 ,maxwell1 ,o4 ,e4 ,mey]1 ,los*midt1 ,lo?> ,mey]1 ,van d] ,waals1 ,mossotti1 ,planck1 ,sir ,j4 ,j4 ,?omson1 & o!rs1 h arriv$ at e/imates ( ! magnitude & numb] ( molecules 9 a gas4 ,^! e/imates necess>ily v>y ) ! hypo!ses made 9 d$uc+ !m4 ,x w\ld s]ve no useful purpose to give ! results1 s9ce ! figures convey no impression to ! m9d ( ! m9ut5ess ( molecules1 or ev5 z to ! extraord9>y numb] ( !m 91 say1 s small a volume z "o cubic c5timetre4 ,z an example1 x has be5 calculat$ t !re are ab\t #fdj trillions ( hydrog5 molecules 9 "o milligram ( ! gas4#c #c ,o4 ,e4 ,mey]1 ,! ,k9etic ,!ory ( ,gases1 #ahii4 99 99 99 99 99 ,9 ! prec$+ volume a %ort acc\nt has be5 giv5 ( ! hi/ory ( ! e>ly attempts to effect ! liquefaction ( ! gases4 ,^! result$ 9 _! division into ! two classes ( liquefiable & p]man5t gases4 ,"o ( ! mo/ notable a*ievem5ts ( ! latt] half ( ! la/ c5tury 0 to sweep away ?is arbitr>y di/9ction4 ,! fundam5tal condition ne$$ to effect ! liquefaction ( a gas1 al?\gh surmis$ by ,f>aday1 0 fir/ cle>ly indicat$ by ,&rews ab\t #ahfc4 ,he %[$ t1 9 ord] to liquefy a gas1 its temp]ature mu/ be l[]$ to a po9t peculi> to ea* gas1 :51 on ! application ( suffici5t pressure1 x w become a liquid4 ,?us1 9 ! case ( gase\s c>bon dioxide1 ,&rews f\nd t1 if its temp]ature 7 ma9ta9$ above #ca ,c41 no am\nt ( pressure w\ld cause x to liquefy2 if ! temp]ature 7 l[]$ j bel[ ?is po9t--t]m$ ! critical po9t--a pressure ( #ge atmosph]es w\ld effect its liquefaction4 ,on ! o!r h&1 if ! temp]ature ( ! liquid c>bon dioxide be sl[ly rais$ to ab\t #ca1 ! surface ( dem>cation betwe5 ! liquid & ! gas becomes gradually fa9t] & ev5tually disappe>s4 ,c>bon dioxide may ?us be made to pass f ! /ate ( liquid to t ( gas )\t any sudd5 alt]ation ( volume4 ,if a giv5 volume ( ! gas1 say at #ej1 be expos$ to gradually increas+ pressure1 say up to #aej atmosph]es1 ! volume is gradually dim9i%$ ) ! increm5t ( pressure1 b no sudd5 contraction indicat+ liquefaction occurs4 ,if ! gas "u ! high pressure be all[$ to cool d[n to ! ord9>y temp]ature1 no sudd5 contraction is obs]v$ to foll[4 ,! c>bon dioxide1 at ! outset a gas1 9 ! end becomes a liquid by a gradual & cont9u\s transition1 unaccompani$ by any abrupt *ange ( volume4 ,^! obs]vations %[ t :at we /yle ! liquid & gase\s /ates are simply sep>at$ manife/ations ( ! same condition ( matt]4 ,!re is a def9ite temp]ature = e gase\s sub/ance at :i* x ceases to be liquefiable "u pressure2 & ! reason t ,f>aday fail$ to liquefy c]ta9 gases 0 t he 0 unable1 ) ! means at 8 comm&1 to l[] _! temp]atures suffici5tly & s rea* _! critical po9ts2 h5ce ! enorm\s pressures :i* he & o!r inve/igators appli$ 7 unavail+4 ,^! facts 7 def9itely made kn[n by ,&rews 9 #ahfi1 7 !oretically develop$ by ,van d] ,waals 9 #ahgc1 & practically appli$ to ! liquefaction ( oxyg5 9 #ahgg1 indep5d5tly & almo/ simultane\sly1 by ,pictet1 ( ,g5eva1 & ,cailletet1 ( ,*tillon-sur-,se9e4 ,pictet expos$ oxyg51 "u great pressure1 to ! cold produc$ by ! rapid evaporation ( liquid c>bon dioxide2 ,cailletet br\ght ab\t ! same result by sudd5ly dim9i%+ ! t5sion ( ! /rongly compress$ oxyg51 ! rapid expansion ( ! gas effect+ ! r$uction ( its temp]ature bel[ ! critical po9t4 ,o!r work]s took up ! subject1 notably ,wroblewski & ,olszewki 9 ,pol&1 ,dew> 9 ,engl&1 & ,kamm]l+h ,onnes 9 ,holl&2 & ! liquefaction ( all ! gases has n[ be5 accompli%$4 ,! foll[+ table %[s ! absolute boil+-7,b4,p47 & melt+-po9ts 7,m4,p471 critical po9ts 7,c4,p471 & pressures 7,c4,press471 toge!r ) ! d5sity 7,d7 at _! boil+-po9ts ( a numb] ( liquefi$ gases3 ,c4 ,b4 ,p4 ,m4 ,p4 ,c4 ,p4 ,press4 ,d4 degrees degrees degrees m4 ,helium #d4e ---- ---- ---- #j4ae ,hydrog5 #bj #ae #ce #aa4f #j4jf ,oxyg5 #ij4e bel[ #ej #aed #dd #a4aca ,nitrog5 #gg4e #fj #abd #bj4i #j4gia ,me?ane #ajh4c ---- #aia #db4d #j4daf ,e?yl5e #afi4e #ajd #bhb #dd #j4ega ,fluor9e #ahf #dj ---- ---- #a4aa ,*lor9e #bci4f ---- ---- ---- #a4ejg ,ammonia #bcd4e #aig4e #djd #he4i ---- ,neon #cj4dj ---- bel[ #fe ---- ---- ,argon #hf4ij ---- #aee4f #dj4b #a4bab ,krypton #aba4cc ---- #baj4e #da4b #b4aee ,x5on #afc4i ---- #bhg4h #dc4e #c4eb ,! pr9ciple ( ! ,cailletet me?od ( effect+ ! liquefaction ( oxyg5 _h be5 !oretically & exp]im5tally /udi$ by ,j\le & ,"l ,kelv9 _m ye>s previ\sly4 ,x 0 ext5d$ by ,siem5s & has be5 appli$ by ,l9de & ,hampson to ! con/ruction ( ma*9]y = ! production ( liquid air on a l>ge scale1 )\t ! use ( any int]m$iate refrig]ant4 ,x is n[ readily possible to procure consid]able quantities ( liquid air1 & ev5 ( liquid hydrog54 ,by ! evaporation ( liquid hydrog5 temp]atures approa*+ ! absolute z]o--t is1 #bgc ,c4 bel[ ! melt+-po9t ( ice--c n[ be rea*$4 ,incid5tally !re has be5 develop$ a special field ( inquiry relat+ to ! behavi\r ( sub/ances at l[ temp]atures4 ,illu/ration3 ,,sir ,,james ,,dew>4 ,! pione]s 9 ?is field h be5 ,dew> 9 ,engl& & ,kamm]l+h ,onnes 9 ,holl&4 ,rese>* at l[ temp]atures1 inde$1 has be5 ! ma9 feature ( ! "w ( ! ,royal ,in/itution ( ,great ,brita9 dur+ ! la/ tw5ty ye>s4 ,x has includ$ obs]vations at temp]atures approa*+ ! absolute z]o1 on ! electrical resi/ivity ( metals & alloys1 on ! behavi\r ( s-call$ insulators1 on *anges 9 ! cohesive =ce ( metals1 on ! dielectric con/ants ( froz5 electrolytes1 on ! influ5ce ( cold on magnetisation & on magnetic p]meability1 & on ! optical behavi\r ( bodies1 on vital ph5om5a at l[ temp]atures1 & on ! influ5ce ( cold on *emical *ange4 ,dew> has succe$$ 9 liquefy+ & solidify+ l>ge quantities ( hydrog51 & has /udi$ its prop]ties at l[ temp]atures4 ,liquid hydrog5 is transp>5t & col\rless4 ,x is a non-conductor ( electricity1 & gives no absorption spectrum4 ,x freezes into an ice-l solid1 devoid ( metallic prop]ties4 ,dew> has made use ( ! prop]ty possess$ by *>coal ( occlud+ gases1 especially at l[ temp]atures1 9 ! production ( high vacua1 & 9 ! sep>ation ( gases2 & he has also det]m9$ ! molecul> heat ( absorption by *>coal ( v>i\s gases4 ,he has employ$ liquid air1 liquid nitrog51 & liquid hydrog5 z calorimetric ag5ts1 & has det]m9$ by means ( !m ! heat capacities ( a numb] ( sub/ances at v l[ temp]atures4 ,la/ly1 8 +5i\s contrivance ( silv]$ vacuum protect$ vessels1 n[ introduc$ into comm]ce "u ! "n ( 8,!rmos flasks10 has greatly facilitat$ ! manipulation ( liquefi$ gases = exp]im5tal purposes4 ,,*apt] ,,vi ,,! ,,p]iodic ,,law ,9 an anonym\s essay 8,on ! ,relation betwe5 ! ,specific ,gravities ( ,bodies 9 _! ,gase\s ,/ate & ! ,weights ( _! ,atoms10 publi%$ 9 ,?omson's ,annals ( ,philosophy 9 #ahae1 ! attempt 0 made to indicate c]ta9 consequ5ces :i* seem to foll[ f ,dalton's law ( gase\s volumes1 z g5]alis$ by ,gay ,lussac4 ,! au?or ( ?is essay 0 subsequ5tly discov]$ to be a m$ical /ud5t nam$ ,william ,pr\t1 notewor?y z hav+ be5 "o ( ! fir/ to po9t out ! sugge/iv5ess ( ! num]ical relation%ips :i* occur among ! atomic weights ( ! elem5ts4 ,?is pap] is usually assum$ to conta9 ! /atem5t t ! atomic weights ( ! elem5ts are multiples ( t ( hydrog54 ,z a fact1 h[ev]1 ?is hypo!sis is n[h]e explicitly /at$ 9 ! pap]4 ,! inf]5ce 0 practically due to ,?omson1 :o /rove to support x by exp]im5tal pro( ( s weak a "* z to draw =? ! rem>k ( ,b]zelius t mu* ( x appe>$ to h be5 made at ! writ+-desk4 ,nev]!less1 ! occurr5ce ( su* num]ical relation%ips cont9u$1 z already /at$1 to excite speculation4 ,db]e9]1 9 #ahbi1 po9t$ out t 9 c]ta9 gr\ps ( correlat$ elem5ts1 consi/+ ea* ( ?ree memb]s1 ! middle memb] _h an atomic weight practically id5tical ) ! ari?metic mean ( ! atomic weights ( ! o!rs2 & simil> obs]vations 7 made by ,gmel91 ,dumas1 ,glad/one1 & ,/reck]4 ,an approa* to ! recognition ( ! g5]al law und]ly+ ^! facts 0 made by ,newl&s 9 ,engl&1 & indep5d5tly by ,de ,*anc\rtois 9 ,france1 :o 7 ! fir/ to indicate t ! prop]ties ( ! elem5ts are relat$ to _! atomic weights4 ,?is conception 0 develop$ by ! ,russian *emi/1 ,m5deleff4 ,9 ,m5deleff's arrangem5t1 fir/ publi%$ 9 #ahfi1 ! elem5ts are s gr\p$ t _! prop]ties are p]iodic functions ( _! atomic weights4 ,! g5]al /atem5t ( :at is n[ kn[n z ! ,p]iodic ,law may be put 9 ?is =m3 ,if ! elem5ts are arrang$ 9 ord] ( increas+ atomic weight1 ! prop]ties ( ^! elem5ts v>y f memb] to memb] ( ! s]ies1 b return m or less ne>ly to ! same value at c]ta9 fix$ po9ts 9 ! s]ies4 ,?is is obs]v$ to occur 9 ! atomic value1 or val5cy1 ( ! sev]al memb]s2 also 9 _! specific volumes1 melt+-po9ts1 ductility1 h>dness1 volatility1 cry/all9e =m1 !rmal expansion1 refraction equival5ts1 & conductivities = heat & electricity1 9 _! magnetic prop]ties & electro-*emical behavi\r1 & 9 _! heats ( *emical comb9ation1 etc4 ,! fir/ *emi/ ( note to grasp ! significance ( ,m5deleff's g5]alisation 0 ,lo?> ,mey]1 :o1 deal+ at ! outset ) "o ( ! *>act]i/ic prop]ties ( ! elem5ts--viz41 _! specific or atomic volumes 7t is1 ! values obta9$ by divid+ _! specific gravities into _! respective atomic weights7--greatly develop$ ! pr9ciple ( p]iodicity1 repres5t+ x graphically 9 a mo/ /rik+ & sugge/ive mann]1 lead+ up to a classification almo/ id5tical ) t ( ,m5deleff4 ,s9ce ! date ( its promulgation ! s*eme ( classification ( ! elem5ts 9 accordance ) ! pr9ciple ( p]iodicity has exp]i5c$ c]ta9 m9or modifications necessitat$ by full] k2 b 9 its ess5tial features x rema9s v mu* 9 ! =m devis$ by ,m5deleff4 ,! discov]y ( ! s-call$ in]t & radio-active elem5ts requir$ t _! relations to ! p]iodic law %\ld be def9$4 ,_! inclusion raises no fundam5tal difficulty4 ,inde$1 ! g5]alisation seems to adapt itself to ! f>-rea*+ consid]ations :i* spr+ f mod]n views ( ! nature ( ! atom1 its electro-*emical relation%ips1 & ! ord]ly arrangem5t ( ! corpuscles ( :i* x may be compos$4 ,9 ! #aije edition ( ! ,engli% translation ( 8 fam\s ,pr9ciples ( ,*emi/ry1 ,m5deleff has giv5 a table :i* may be said to embody 8 f9al views conc]n+ ! sy/ematic classification ( ! elem5ts4 ,?is is reproduc$ on p4 #aje4 ,9 ?is table he po/ulates ! exi/5ce ( two hypo!tical elem5ts1 x & y1 ! =m] ( :i* he reg>ds z id5tical ) ! physical e!r2 :ile ! latt] is an analogue ( helium1 possibly id5tical ) ! 8coronium0 ( ! sol> coronal atmosph]e1 ) a molecul> weight ( ab\t #j4d4 ,! /rik+ feature ( ,m5deleff's g5]alisation is its univ]sality4 ,9 ?is respect x diff]s f all previ\s attempts at natural classifications ( ! elem5ts2 ^! 7 limit$ & p>tial1 & !re=e unsatisfactory4 ,nev]!less1 x is easy to trace 9 !m fundam5tal conceptions ^u :i* ,m5deleff built4 ,m5deleff1 9 fact1 gave a great ext5sion to ideas ) :i* ! *emical _w ( half a c5tury ago 0 m or less famili>2 & d\btless x 0 ?is circum/ance1 comb9$ ) ! rem>kable boldness & compreh5siv5ess ( ?is ext5sion1 foll[$ almo/ imm$iately by a mo/ /rik+ s]ies ( confirmations ( 8 own previsions1 z logical consequ5ces ( 8 g5]alisation1 t secur$ = x att5tion1 & ultimately univ]sal adoption4 ---------------------------------------- ---------------- ,s]ies4,z]o gr\p4 ,gr\p ,i4 ,gr\p ,,ii4 ,gr\p ,,iii4 ---------------------------------------- ---------------- #j x ---- ---- ---- #a y ,hydrog54 ,h #a4jjh ---- ---- #b ,helium4 ,li?ium4 ,b]yllium4 ,boron4 ,he #d4j ,li #g4jc ,be #i4a ,b #aa4j #c ,neon4 ,sodium4 ,magnesium4 ,alum9ium4 ,ne #ai4i ,na #bc4je ,mg #bd4a ,al #bg4j #d ,argon4 ,potassium4 ,calcium4 ,sc&ium4 ,ar #ch ,k #ci4a ,ca #dj4a ,sc #dd4a #e ---- ,copp]4 ,z9c4 ,gallium4 ,cu #fc4f ,zn #fe4d ,ga #gj4j #f ,krypton4 ,rubidium4 ,/rontium4 ,yttrium4 ,kr#ha4h ,rb #he4d ,sr #hg4f ,y #hi4j #g ---- ,silv]4 ,cadmium4 ,indium4 ,ag #ajg4i ,cd #aab4d ,9 #aad4j #h ,x5on4 ,csium4 ,b>ium4 ,lan?anum4 ,xe #abh ,cs #acb4b ,ba #acg4d ,la #aci #i ---- ---- ---- ---- #aj ---- ---- ---- ,ytt]bium4 ,yb #agc #aa ---- ,gold4 ,m]cury4 ,?allium4 ,au #aig4b ,hg #bjj4j ,tl #bjd4a #ab ---- ---- ,radium4 ---- ,rd #bbd ---------------------------------------- ---------------- ---------------------------------------- ---------------- ,s]ies4 ,gr\p ,,iv4 ,gr\p ,v4 ,gr\p ,,vi4 ,gr\p ,,vii4 ---------------------------------------- ---------------- #j ---- ---- ---- ---- #a ---- ---- ---- ---- #b ,c>bon4 ,nitrog54 ,oxyg54 ,fluor9e4 ,c #ab4j ,n #ad4jd ,o #af4j ,f #ai4j #c ,silicon4 ,phosphorus4 ,sulphur4 ,*lor9e4 ,si #bh4d ,p #ca4j ,s #cb4jf ,cl #ce4de #d ,titanium4 ,vanadium4 ,*romium4 ,manganese4 ,ti #dh4a ,v #ea4d ,cr #eb4a ,mn #ee4j #e ,g]manium4 ,ars5ic4 ,sel5ium4 ,brom9e4 ,ge #gb4c ,z #ge4j ,se #gi4j ,br #gi4ie #f ,zirconium4 ,niobium4 ,molybd5um4 ---- ,zr #ij4f ,nb #id4j ,mo #if4j #g ,t94 ,antimony4 ,tellurium4 ,iod9e4 ,sn #aai4j ,sb #abj4j ,te #abg ,i #abg #h ,c]ium4 ---- ---- ---- ,ce #adj #i ---- ---- ---- ---- #aj ---- ,tantalum4 ,tung/54 ---- ,ta #ahc4j ,w #ahd #aa ,lead4 ,bismu?4 ---- ---- ,pb #bjf4i ,bi #bjh #ab ,?orium4 ---- ,uranium4 ---- ,? #bcb ,u #bci ---------------------------------------- ---------------- ----------------------- ,s]ies4 ,gr\p ,,viii4 ----------------------- #j -- #a -- #b -- #c -- ,iron4 ,fe #ee4i #d ,cobalt4 ,co #ei ,nickel4 ,ni #ei7;,cu7 #e -- ,ru!nium4 ,ru #aja4g #f ,rhodium4 ,rh #ajc4j ,palladium4 ,pd #ajf4e7;,ag7 #g -- #h -- #i -- ,osmium4 ,os #aia #aj ,iridium4 ,ir #aic ,plat9um4 ,pt #aid4i7;,au7 #aa -- #ab -- ------------------------ ,! p]iodic law1 9 ! words ( its au?or1 is ! 8direct outcome ( ! /ock ( g5]alisations ( e/abli%$ facts :i* _h be5 accumulat$ by ! end ( ! decade #ahfj-ahgj40 ,x is f\nd$ :olly on exp]im5t1 & is z mu* ! embodim5t ( fact z are ! laws ( *emical comb9ation4 ,x 0 bas$ ^u ! adoption ( ! def9ite num]ical values ( ! atomic weights1 z indicat$ by ,cannizz>o1 z a consequ5ce ( ! hypo!sis ( ,avogadro1 & ^u ! assumption t ! relations betwe5 ! atomic weights ( analog\s elem5ts mu/ be gov]n$ by a g5]al law4 ,! application ( ! p]iodic law imm$iately l$ to ! re-det]m9ation ( c]ta9 atomic weights & to ! correction ( _! assum$ atomic values4 ,at ! "t ( its enunciation ! det]m9ation ( ! val5cy ( an elem5t 0 purely empirical1 ) no app>5t necess>y relation to t ( o!r elem5ts4 ,we f9d n[ t ! val5cy is a matt] ( a priori k1 j z mu* z any o!r prop]ty ( ! elem5t4 ,! am5d$ values = ! atomic weight & val5cy ( a numb] ( elem5ts ?us dem&$ by ! law h be5 confirm$ by all ! exp]im5tal crit]ia employ$ by *emi/s4 ,! g5]alisation fur!r indicat$ ! exi/5ce ( new elem5ts2 x po9t$ out _! probable s\rces1 & =etold _! prop]ties4 ,in/ances ( ?is p[] ( div9ation 9 ! law are to be se51 z already m5tion$1 9 ! discov]y ( gallium by ,lecoq de ,boisbaudran1 ( sc&ium by ,nilson1 & ( g]manium by ,w9kl]1 ! exi/5ce & ma9 prop]ties ( :i* 7 sev]ally =etold by ,m5deleff 9 #ahga4 ,! promulgation ( ! law 0 h]ald$ z a pro( ( ! validity ( ! conception ( a primordial matt]4 ,x 0 held t x c f9d a rational explanation only 9 ! idea ( unity 9 ! =mative mat]ial4 ,b its au?or w\ld n admit t 8 g5]alisation _h any relation to ! ,py?agorean hypo!sis3 ,! p]iodic law1 bas$ z x is on ! solid & :olesome gr\nd ( exp]im5tal rese>*1 has be5 evolv$ indep5d5tly ( any conception z to ! nature ( ! elem5ts4 ,x does n 9 ! lea/ orig9ate 9 ! idea ( an unique matt]1 & x has no hi/orical connection ) t relic ( ! torm5ts ( classical ?\ght2 & !re=e x af=ds no m indication ( ! unity ( matt] or ( ! comp\nd nature ( ! elem5ts ?an d ! laws ( ,avogadro1 & ,g]h>dt1 or ! law ( specific heats1 or ev5 ! conclusions ( spectrum analysis4 ,none ( ! advocates ( a unique matt] has ev] tri$ to expla9 ! law f ! /&po9t ( ideas tak5 f a remote antiquity1 :5 x 0 f\nd conv5i5t to admit ! exi/5ce ( _m gods--& ( a unique matt]4 ,! read] :o desires a full] exposition ( ! pr9ciples ( ! p]iodic law mu/ be ref]r$ to special treatises on ! subject1 or to ! l>g] manuals on g5]al *emi/ry4 ,x mu/1 h[ev]1 be /at$ t1 :ile _m facts discov]$ s9ce ! orig9al promulgation ( ! pr9ciple & s9ce its developm5t by ,lo?> ,mey]1 ,c>nelley1 ,?oms51 & o!rs1 are consi/5t ) ! law1 o!r facts1 "s ( :i* 7 kn[n be=e #ahgj1 are app>5tly out ( h>mony ) x1 or at all ev5ts await a full] int]pretation4 ,= example1 tellurium is n 9 its prop] place 9 ! s*eme if its atomic weight1 #abg4e1 has be5 correctly asc]ta9$4 ,cobalt 7#eh4ig7 & nickel 7#eh4fh7 h atomic weights s closely accordant t _! prop]ties & ^? ( _! correspond+ comp\nds %\ld be v simil>1 &1 9 fact1 almo/ id5tical2 b su* is n ! case4 ,inde$1 x has be5 said1 no prevision ( ! p]iodic law w\ld h l$ to ! discov]y ( nickel4 ,simil> consid]ations apply to manganese1 *romium1 & iron2 ! atomic weights ( ^! elem5ts are less widely diff]5t ?an ! diff]5ces 9 _! prop]ties & ! div]g5ce 9 _! *emical relation%ips w\ld seem to require4 ,! relative positions ( argon & potassium are also n consi/5t ) ! law4 ,!re are difficulties1 too1 connect$ ) :at we "k at pres5t conc]n+ ! atomic weights ( ! s-call$ r>e e>? metals4 ,9 spite1 h[ev]1 ( ^! seem+ anomalies1 x c h>dly be d\bt$ t ! p]iodic law is z mu* ! expression ( a natural law z is ! law ( gravitation2 al?\gh x is possible1 & inde$ probable1 t1 z we n[ def9e x1 x is only ! fir/ approximation to ! tru?1 & t1 z our k becomes m precise1 ,m5deleff's classification1 9 its pres5t =m1 w require modification & ext5sion1 j z ,m5deleff's own s*eme may be said to be a modification & ext5sion ( ! attempts at ! rational classification ( ! *emical elem5ts made by 8 pr$ecessors4 ,illu/ration3 ,,dmitri ,,ivan[its* ,,m5del,,eff4 ,dmitri ,ivan[its* ,m5deleff1 ) ^: "n ?is fruitful g5]alisation is indissolubly connect$1 0 born ,febru>y #g1 #ahcd 7,n4,s471 at ,tobolsk1 9 ,sib]ia1 & 0 ! f\rte5? & y\nge/ *ild ( ,ivan ,m5deleff1 ! ,director ( ! gymnasium at t place4 ,soon aft] ! bir? ( ,dmitri 8 fa!r became bl9d1 & ! family 7 practically dep5d5t ^u ! "m1 ,m>ia ,dmitrievna ,m5deleeva1 :o e/abli%$ a glass works ne> ,tobolsk1 on ! pr(its ( :i* %e br\ght up & educat$ h] l>ge family4 ,at ! age ( fifte5 ,m5deleff 0 tak5 by 8 "m to ,/4 ,pet]sburg1 & began ! /udy ( natural sci5ce at ! ,physico-,ma!matical ,faculty ( ! ,in/itute4 ,aft] s]v+ z a sci5ce ma/] at ,simf]opol 9 ! ,crimea & at ,odessa1 9 #ahef he became a privat-doc5t 9 ! ,univ]sity2 !n1 foll[+ a %ort p]iod ( /udy 9 ,france & ,g]many1 he return$ to ,/4 ,pet]sburg1 & 9 #ahff he 0 made ,pr(essor ( ,g5]al ,*emi/ry 9 ! ,univ]sity4 ,8 reputation ma9ly re/s ^u 8 contributions to *emical philosophy & physical *emi/ry1 notably on specific volumes1 on critical temp]atures1 on ! !rmal expansion ( liquids1 on ! nature ( solutions1 on ! ela/icity ( gases1 & ! orig9 & nature ( petroleum4 ,he di$ on ,janu>y #ca1 #aijg4 ,,*apt] ,,vii ,,val5cy ,*emical =mul1 f ! "t ( ,b]zelius onw>ds1 h be5 reg>d$ z rational expressions--t is1 !y s]ve to repres5t ! relations & analogies ( ! sub/ance !y are employ$ to designate1 & indicate 9 ! simple/ & at ! same "t ! mo/ compreh5sive mann] ! *emical *anges 9 :i* ! sub/ances take "p4 ,9 ! words ( ,g]h>dt1 ^? =mul are 8! be/ t make evid5t ! greate/ numb] ( su* relations & analogies10 & t s]ve to express ! greate/ numb] ( ! *emical *anges 9 :i* !y are conc]n$4 ,9 su* concrete expressions ( *emical *ange x 0 frequ5tly obs]v$ t a def9ite gr\p ( "s or all ( ! con/itu5t elem5ts ( ! sub/ance hung toge!r1 z x 71 & pass$1 app>5tly un*ang$1 into ! products ( its trans=mation4 ,^! gr\ps 7 n necess>ily radicals 9 ! s5se 9 :i* ,liebig & ,whl] us$ ! t]m2 to ,g]h>dt & to ,kekul !y 7 simply residues1 rema9+ unattack$ 9 a *emical metamorphosis1 & pass+ z su* into ! products ( ! *ange4 ,!y might or might n be capable ( isolation z def9ite entities4 ,?us1 = example1 we may repres5t ! composition ( ! foll[+ sulphur comp\nds s z to %[ t !y all conta9 ! gr\p ,,s#b1 or sulphuryl3 ,,s#b;,cl ,,s#b;,cl ,cl ,,oh ,sulphuryl *loride4 ,*lorosulphonic acid4 ,,s#b,,no#b ,,s#b,,no#b ,,s#b,,oh ,cl ,,oh ,,oh ,sulphuryl nitryl ,lead5 *amb] ,sulphuric *loride4 cry/als4 acid4 ,^! =mul s]ve to %[ h[ ! sev]al sub/ances are mutually relat$1 & t !y may be d]iv$ f "o ano!r by ! sub/itution ( atoms ( *lor9e = hydroxyl 7,,oh71 or nitryl 7,,no#b71 or vice v]sa4 ,x 0 po9t$ out 9 #ahea by ,williamson1 & subsequ5tly by ,g]h>dt1 t ^! gr\ps are *>act]is$ by diff]5ces 9 _! p[] ( comb9+ ) or replac+ atoms ( hydrog51 or ( gr\ps or elem5ts :i*1 l *lor9e1 are *emically equival5t to hydrog54 ,su* a radical or residue z e?yl 7,c#b;,h#e7 is *emically equival5t to "o atom ( hydrog51 z is %[n :5 we comp>e ! =mula = e!r1 z e/abli%$ by ,williamson1 ) t ( ord9>y alcohol3 ,c#b;,h#e,o ,c#b;,h#e,o ,h ,c#b;,h#e ,alcohol4 ,e!r4 ,sulphuryl1 ,,s#b1 is *emically equival5to two atoms ( hydrog52 phosphoryl1 ,,po1 z sugge/$ by ,odl+1 to ?ree atoms ( hydrog54 ,g]h>dt !re=e propos$ to designate ^! & simil> gr\ps z monatomic1 diatomic1 triatomic1 accord+ to _! respective hydrog5-replac+ p[]4 ,?is conception ( ! def9ite atom-fix+ or replac+ p[] ( gr\ps or comp\nd radicals 0 ext5d$ by ,frankl&1 9 #aheb1 s z to include ! simple radical--t is1 ! elem5ts4 ,9 ! memoir 9 :i* he ann\nc$ ! exi/5ce ( ! organometallic comp\nds he po9t$ out t ! elem5ts may be classifi$ accord+ to _! comb9+ p[]1 or1 z he express$ x1 accord+ z 8_! aff9ities are be/ satisfi$40 ,?is idea 0 indep5d5tly develop$ by ,c\p] & ,kekul 9 #aheh2 x is f t p]iod t ! def9ite introduction ( ! conception ( atomicity1 atomic-value1 or val5cy1 into *emical doctr9e may be said to date4 ,! memoir 9 ,liebig's ,annal5 d] ,*emie und ,ph>macie1 9 :i* ,kekul ann\nc$ 8 views1 deals p>ticul>ly ) ! tetraval5cy ( c>bon & ! doctr9e ( l9k+ ( atoms 9 t]ms ( _! val5cy4 ,z =mulat$ by ,kekul & z subsequ5tly develop$ 9 8 fam\s text-book1 ?is doctr9e ex]cis$ an imm$iate effect on ! progress ( ! *emi/ry ( c>bon comp\nds4 ,l e fruitful hypo!sis1 x /imulat$ inquiry1 & br\ght out analogies2 & ! m x 0 appli$ ! m app>5t became its sugge/iv5ess & utility4 ,! scope ( *emical =mul 0 greatly ext5d$4 ,rational =mul grew into dissect$ or con/itutional =mul2 & on ! sy/em ( con/itutional =mul h be5 graft$ successive attempts to elucidate ! mann] 9 :i* ! con/itu5ts ( a molecule are gr\p$ & held toge!r4 ,x is int]e/+ to note t ! proximate effect ( ! !ory ( *emical /ructure :i* grew out ( ,kekul's doctr9e 0 to assimilate :at 0 s\nd 9 ! seem+ly antagoni/ic !ories ( types & radicals4 ,z a mode ( exposition1 ,kekul us$ models to illu/rate ! mann] 9 :i* ! aff9ity-values ( comp\nds are satisfi$2 ^! 7 n int5d$ to repres5t ! actual spatial di/ribution ( ! atoms 9 a molecule1 b !y nev]!less famili>is$ ! m9d ) ! idea fir/ cle>ly recognis$ by ,wolla/on & ,b]zelius t ?is is ! ultimate aim ( *emi/ry4 ,x 0 probably _! use1 ei!r actually or by visualisation1 t l$ ,kekul 9 #ahfe to 8 !ory ( ! con/itution ( b5z5e1 z develop$ 9 8 pap] on ! con/itution ( ! aromatic comp\nds--a !ory no less fruitful 9 its consequ5ces ?an t ( ! tetraval5cy ( c>bon & ( ! l9kage ( atoms4 ,su* models1 too1 9 ! h&s ( ,van 't ,h(f1 subsequ5tly s]v$ to elucidate ! connection betwe5 optical *>act]s & cry/all9e =m1 & to expla9 ! isom]ism ( c]ta9 organic sub/ances4 ,kekul 0 ( op9ion t ! val5cy1 or aff9ity-value1 ( an elem5t 0 a def9ite & inv>iable quantity--a fundam5tal prop]ty ( ! atom z immutable z its atomic weight4 ,_m facts appe> to %[ t su* is n ! case4 ,?us phosphorus & nitrog5 are sometimes trival5t & at o!r times p5taval5t2 t91 9 c]ta9 ( its comp\nds1 is dival5t2 9 o!rs1 tetraval5t4 ,sulphur may be a dyad1 a tetrad1 or a hexad4 ,x w be se5 t ! val5cy ( ^! p>ticul> elem5ts v>ies by two units3 ?is 0 at "o "t held to be a natural law1 & ! v>i\s elem5ts 7 divid$ by ,frankl& into ! two ma9 gr\ps ( 7#a7 p]issads1 or elem5ts ( odd atomic value1 & 7#b7 artiads1 or elem5ts ( ev5 atomic value4 ,exp]i5ce has demon/rat$ t a rigid classification on ?is basis is n possible4 ,_m in/ances are kn[n ( elem5ts n only v>y+ 9 val5cy by two units1 b ev5 by "o unit4 ,?us nitrog51 :i* is usually a p]issad1 is app>5tly an artiad 9 nitric oxide & 9 gase\s nitrog5 p]oxide4 ,roscoe has %[n t uranium & tung/51 orig9ally reg>d$ z artiads1 =m p5ta*lorides4 ,to :at ! diff]5ce 9 ! aff9ity-value ( an elem5t is due1 & :y diff]5t elem5ts %\ld manife/ diff]5t values1 is at pres5t unkn[n4 ,val5cy1 l o!r prop]ties1 appe>s to be a p]iodic function ( atomic weight2 f ! behavi\r ( su* analog\s comp\nds z phosphorus p5tafluoride1 phosphorus p5ta*loride1 phosphorus p5tabromide1 x seems1 too1 to be relat$ to ! weights ( ! atoms 9 comb9ation4 ,fur!r1 x w\ld appe> t ! mutual aff9ities ( sub/ances v>y ) temp]ature--i4e41 ) ! en]gy imp>t$ to _! molecules2 num]\s in/ances appe> to indicate t ! atom-fix+ p[] ( an elem5t decreases :5 x is /rongly heat$--t is1 :5 ! int]nal en]gy imp>t$ to its comb9ations exce$s a c]ta9 limit+ value4 ,van 't ,h(f has attempt$ a me*anical explanation ( val5cy dep5d+ on ! %ape ( ! atoms1 z affect$ by v>iation 9 _! vibratory motions result+ f diff]5ces ( temp]ature4 ,helmholtz sugge/$ t ! diff]5t *>ges ( electricity associat$ ) ! atoms may det]m9e _! aff9ity-values--t1 = example1 a monad c>ries a s+le *>ge1 a dyad two1 a triad ?ree *>ges4 ,_m consid]ations g to %[ t ! aff9ity-value ( an elem5t is n capable ( def9ite num]ical expression 9 ! s5se :i* ! doctr9e ( val5cy z g5]ally und]/ood implies1 & t ! v>iations are n ( ! p] saltum "* assum$ by say+ t ! aff9ity-value is sometimes #a1 sometimes #b1 at o!r times #c1 & s on4 ,:5 we h app>5tly satisfi$ ! accept$ atomic value ( an elem5t by allocat+ to x :at we reg>d z ! necess>y complem5t ( atoms ( o!r bodies1 x is frequ5tly evid5t t ! capacity = comb9ation ( ! :ole molecule is n satisfi$4 ,_m app>5tly saturat$ molecules h ! p[] ( comb9+ ) o!r equally saturat$ molecules4 ,sulphur trioxide 7,,s#c7 & b>ium monoxide 7,ba,o7 w\ld appe> ea* to h _! aff9ity-values satisfi$2 nev]!less !y comb9e ) great read9ess to =m b>ium sulphate1 ,ba,s,o#d4 ,,*apt] ,,viii ,,! ,,*emi/ry ,,( ,,aromatic ,,comp\nds ,! sugge/ions ( ,c\p] & ,kekul t an explanation ( ! prop]ties ( *emical comp\nds %\ld be s\ght 9 ! nature & mutual aff9ities ( _! con/itu5t elem5ts r ?an ( _! radicals 7 n :olly accept$ at ! "t !y 7 fir/ made4 ,speculative ideas h to ju/ify !mselves by facts4 ,! value ( an hypo!sis dep5ds ^u its usefulness & exp$i5cy1 & on its p[] ( indicat+ ! l9es ( future inquiry4 ,h[ f> x is inductively s\nd & d$uctively useful is a matt] = individual judgm5t4 ,consequ5tly ! t5d5cy to pass f purely rational & con/itutional =mul to =mul :i* s\ght to symbolise ! inn] /ructure--! v skeleton1 z x 7--( a molecule1 0 resi/$ = a "t1 & by no "o m /rongly ?an by ,kolbe4 ,kolbe's attitude to ! new doctr9e may be said to h _h its ju/ification 9 8 own "w4 ,8 rem>kable pr$iction1 bas$ on consid]ations :i* _h no?+ 9 common ) ,kekul's doctr9e1 ( ! exi/5ce ( ! second>y & t]ti>y alcohols1 s soon to be confirm$ by ,fri$el's discov]y ( second>y propyl alcohol1 & by ,butl]['s isolation ( t]ti>y butyl alcohol1 s]v$ to ret>d ! g5]al adoption ( ,kekul's views by %[+ t app>5tly !y 7 no m fruitful 9 sugge/iv5ess ?an ^? !y 7 int5d$ to supplant4 ,b x 0 exactly 9 _! sugge/iv5ess ) reg>d to ! developm5t ( isom]ism t /ructural =mul bas$ ^u val5cy 7 gradually f\nd to be mo/ useful4 ,x 0 p]ceiv$ t x 0 n[ possible n only to =etell ! exi/5ce ( isom]s1 b to det]m9e _! numb]1 & to "s ext5t to =eca/ _! prop]ties & modes ( decomposition4 ,cayley1 = example1 calculat$ ! numb] ( possible isom]s ( ! hydroc>bons ( ! g5]ic =mula ,cn,h#bn#b up to ,c#f;,h#ad all ^? t !ory pr$ict$ h be5 discov]$4 ,9 no s+le case h m be5 obta9$ ?an ! numb] indicat$ by !ory4 ,! accumulat$ weight ( ?is & simil> te/imony ultimately e/abli%$ ! doctr9e ( *emical /ructure on a firm basis4 ,?is conception receiv$ a great ext5sion z ! result ( ,kekul's application ( 8 ideas to ! explanation ( ! *emical con/itution ( ! gr\p ( sub/ances ( vegetable orig9--consi/+ ( ess5tial oils1 balsams1 res9s1 & _! products1 :i*1 on acc\nt ( _! *>act]i/ic od\rs1 7 collectively kn[n to ! old] *emi/s z ! aromatic comp\nds4 ,"s ( ^!1 l oil ( bitt] almonds1 gum b5zo91 c\m>91 oil ( w9t]gre51 oil ( anise1 oil ( c9namon1 oil ( cum91 balsam ( tolu1 ph5ol1 & c]ta9 ( _! d]ivatives1 su* z b5z5e1 anil9e1 salicylic acid1 c9namic acid1 tolu5e1 cym5e1 _h already be5 inve/igat$ ) important !oretical results2 b z a class !y _h receiv$ f> less att5tion ?an ! d]ivatives ( ! great gr\p ( homolog\s radicals ( :i* me?yl is ! initial memb]4 ,( c\rse x 0 "p ( ! doctr9e ( ,liebig--! discov]] ( b5zoyl--t ! aromatic comp\nds also conta9$ specific radicals2 b ! relation ( ^! comp\nds to ^? we n[ call aliphatic 7fatty7 comp\nds 0 n und]/ood1 al?\gh c]ta9 analogies 7 recognis$4 ,9 #ahff ,kekul drew att5tion to ! foll[+ significant peculi>ities ( ! aromatic comp\nds3 7#a7 ,all aromatic comp\nds1 ev5 ! simple/1 are comp>atively ri*] 9 c>bon ?an ! correspond+ class ( fatty 7aliphatic7 comp\nds2 7#b7 among ! aromatic sub/ances1 z among fatty comp\nds1 num]\s homolog\s comp\nds exi/2 7#c7 ! simple/ aromatic sub/ances conta9 at lea/ six atoms ( c>bon2 7#d7 all decomposition products ( aromatic sub/ances %[ a c]ta9 family resemblance2 ! ma9 product ( ! decomposition conta9s at lea/ six atoms ( c>bon--e4g41 b5z5e ,c#f;,h#f1 ph5ol ,c#f;,h#f,o1 etc41 :i* w\ld seem to indicate t all aromatic sub/ances conta9 a nucleus or atomic gr\p+ conta9+ six c>bon atoms4 ,)9 ?is nucleus ! c>bon atoms are 9 clos] connection or d5s] comb9ation1 f :i* x foll[s t all aromatic comp\nds are comp>atively ri* 9 c>bon4 ,m c>bon atoms c !n be add$ to ?is nucleus accord+ to ! same laws t gov]n ! fatty comp\nds4 ,9 ?is way ! exi/5ce ( homolog\s comp\nds may be expla9$4 ,on ! assumption t c>bon is tetraval5t & t its val5cy is con/ant1 ,kekul %[$ h[1 by l9k+ toge!r six c>bon atoms by alt]nate s+le & d\ble bonds1 six aff9ity units may be left free4 ,if we assume t six c>bon atoms are atta*$ to "o ano!r accord+ to ?is law ( symmetry1 we obta9 a gr\p :i*1 reg>d$ z an op5 *a91 conta9s eight unsaturat$ units ( aff9ity3 ----,c,c----,c,c----,c,c---- ,by mak+ ! fur!r assumption t ! two c>bon atoms at ! ends ( ! *a9 are l9k$ toge!r by "o unit ( aff9ity ea*1 a clos$ *a9 7a symmetrical r+7 is obta9$ :i* n[ conta9s six unsaturat$ units ( aff9ity3 -------------- ,c,c----,c,c----,c,c ,f ?is clos$ *a9 all ! sub/ances usually designat$ z 8aromatic comp\nds0 are d]iv$4 ,9 ^! a common nucleus may be assum$3 x is ! clos$ *a9 ,c#f;,a#f1 :]e ,a d5otes an unsaturat$ aff9ity4 ,! six aff9ities ( ?is nucleus may be satisfi$ by six monoval5t elem5ts4 ,!y may also1 :olly or 9 "p1 be satisfi$ by "o aff9ity ( polyval5t elem5ts1 ! latt] necess>ily br++ ) !m o!r atoms into ! comp\nd1 ?us produc+ "o or m side *a9s1 :i* 9 _! turn may be l5g!n$ by ! addition ( o!r atoms4 ,if ea* ( ! free units is satisfi$ by an atom ( hydrog51 we obta9 b5z5e1 :i*1 z ,kekul demon/rat$1 becomes ! c5tre r\nd :i* ! great gr\p ( aromatic comp\nds might be said to revolve4 ,b5z5e 0 discov]$ by ,f>aday 9 #ahbe among ! volatile liquids cond5s$ f ! oil-gas made by ! ,portable ,gas ,company4 ,x _h already play$ a notable "p 9 ! developm5t ( *emical !ory 9 connection ) ! discov]y ( isom]ism4 ,x 0 n[ to play a f> m important rle3 to become1 9 fact1 ! prog5itor ( a great family ( sub/ances1 n only ( !oretical value1 b ( great economic importance4 ,! limits ( ?is "w preclude any attempt to trace 9 detail ! developm5t ( ! conception ) :i* ,kekul enri*$ sci5ce1 or to dilate ^u ! great ext5sion ( b5z5oid or cyclic *emi/ry :i* has result$ f x dur+ ! pa/ =ty ye>s4 ,x has be5 said t ,kekul's memoir on ! b5z5e !ory is ! mo/ brilliant piece ( sci5tific pr$iction to be f\nd 9 ! :ole range ( organic *emi/ry4 ,( c\rse1 on its promulgation x _h to run ! gauntlet ( criticism2 & an army ( eag]1 active work]s 0 soon engag$ 9 te/+ its suffici5cy & 9 develop+ ! ri* prov9ce :i* x fir/ made kn[n4 ,z ! facts multipli$1 o!r /atical =mul 7 sugge/$ by ,dew>1 ,lad5burg1 & ,claus1 b !y h n prov$ m adequate to expla9 ! facts z ^! h become bett] und]/ood4 ,obs]vations :i* seem$ to contradict ,kekul's !ory1 or :i* seem$ to be imp]fectly expla9$ by x1 h1 9 ! light ( full] k1 be5 %[n to be 9 h>mony ) x2 & su* additional pro(s ( agreem5t h !reby s]v$ to /r5g!n its position4 ,its capacity = developm5t is1 inde$1 z 9 ! case ( e o!r hypo!sis ( ! fir/ rank1 "o ( its c>d9al qualities4 ,x adequately expla9s ! con/itution ( great numb]s ( d]ivatives ^: analogies & relations1 ap>t f x1 w\ld h rema9$ obscure & 9 _m cases un9telligible4 ,! symmetrical di/ribution ( ! c>bon & hydrog5 atoms 9 ! b5z5e molecule1 assum$ by ,kekul on indirect gr\nds1 has be5 e/abli%$ by ! indep5d5t inve/igations ( ,lad5burg & o!rs1 & its r+ /ructure has be5 demon/rat$ by ,baey] & ,p]k94 ,purely physical evid5ce1 bas$ ^u its !rmo-*emical & optical *>act]s c be adduc$ 9 its support4 ,det]m9ations ( ! molecul> volume & magnetic rotation ( its comp\nds fur!r s]ve to sub/antiate x4 ,illu/ration3 ,,augu/ ,,kekul ,,von ,,/radonitz4 ,fri$ri* ,augu/ ,kekul 0 born at ,d>m/adt on ,septemb] #g1 #ahbi4 ,aft] pass+ ?r\gh ! gymnasium ( 8 native t[n1 he ent]$1 9 #ahdg1 ! ,univ]sity ( ,giess51 ) ! int5tion ( becom+ an ar*itect4 ,attract$ by ,liebig's tea*+1 he turn$ to *emi/ry1 & work$ ) ,w on amyl sulphuric acid & its salts4 ,9 #ahea he w5t to ,p>is1 he>d ,dumas's lectures1 & =m$ a fri5d%ip ) ,g]h>dt1 ^: ,trait de ,*imie ,organique l>gely m\ld$ 8 views4 ,he became an assi/ant to ,von ,planta1 occupy+ himself ) ! *emi/ry ( ! alkaloids4 ,subsequ5tly he came to ,london1 work$ "u ,/5h\se1 & made ! acqua9tance ( ,williamson1 !n 9 ! full vig\r ( 8 sci5tific activity4 ,"h he discov]$ ?ioacetic acid4 ,x 0 at ?is "t1 also1 t 8 ideas ) reg>d to /ructural *emi/ry began to take %ape4 ,return+ to ,g]many1 he atta*$ himself to ! ,univ]sity ( ,heidelb]g z a privat-doc5t1 & _h = a pupil ,baey]1 :o took up ! /udy ( ! organo-ars5ic comp\nds4 ,9 #aheh he publi%$ 8 memorable pap] 8,on ! ,con/itution & ,metamorphoses ( ,*emical ,comp\nds & on ! ,*emical ,nature ( ,c>bon10 9 :i* he develop$ 8 views on ! l9k+ ( atoms1 out ( :i* has gr[n our sy/em ( con/itutional =mul4 ,! imm$iate result ( ?is celebrat$ memoir 0 a call to ! *emical *air ( ! ,univ]sity ( ,gh5t1 :]e ,kekul _h among o!r /ud5ts ,baey]1 ,hbn]1 ,krn]1 ,lad5burg1 ,l9nemann1 & ,dew>4 ,"h he rema9$ n9e ye>s1 & "h he publi%$ 8 classical ,lehrbu* d] ,organis*5 ,*emie4 ,! ye>s he sp5t 9 ,gh5t 7 ! mo/ productive "t ( 8 c>e]1 & x 0 !re t he develop$ 8 b5z5e !ory--a conception z fruitful z t ( 8 doctr9e ( atom-l9k+4 ,9 #ahfg ,kekul 0 call$ to ,bonn to take *>ge ( ! newly erect$ laboratory :i* ,h(mann _h design$4 ,al?\gh he cont9u$ to "w1 mo/ly 9 collaboration ) 8 pupils1 among :om may be nam$ ,ans*tz1 ,b]n?s51 ,?orpe1 ,c>nelley1 ,clais51 ,dittm>1 ,fran*imont1 ,van 't ,h(f1 ,japp1 ,s*ultz1 ,walla*1 & ,z9cke1 8 heal? aft] #ahgf began to fail4 ,he di$ on ,july #ac1 #ahif4 99 99 99 99 99 ,( c\rse no /atical =mula c be ! ultimate repres5tation ( ! con/itution ( b5z5e4 ,h[ev] conv5i5t & sugge/ive su* a =mula may be1 x c be only a transitional phase 9 its complete *emical & physical hi/ory4 ,kekul 0 e>ly consci\s ( ?is fact1 & sugge/$ a dynamical hypo!sis bas$ ^u a me*anical conception ( val5cy4 ,?is he imag9$ might repres5t ! numb] ( contacts ) o!r atoms :i* a vibrat+ atom exp]i5c$ 9 ! unit ( "t4 ,two atoms ( tetraval5t c>bon1 ea* l9k$ by "o comb9+ unit1 w exp]i5ce f\r oscillations1 /rik+ ea* o!r & ?ree o!r atoms 9 ! unit ( "t1 :ile ! monoval5t hydrog5 atom makes only "o oscillation4 ,! d\bly l9k$ c>bon w collide ) its neighb\r+ atom twice1 & also ) two o!r atoms )9 ! same p]iod4 ,! assumption t ! c>bon atom has a m rapid motion ?an ! hydrog5 atom is1 h[ev]1 n w>rant$ by ! k9etic !ory4 ,o!r dynamic =mul h be5 propos$ by ,knorr & by ,collie4 ,collie & ,baly h fur!r sugge/$ t ! absorption b&s ( b5z5e obs]v$ 9 ! ultra violet ( its spectrum po9t to syn*ron\s oscillations ( its molecule1 due to dynamic *anges 9 ! mak+ & break+ ( ! l9ks betwe5 ! sev]al pairs ( ! c>bon atoms1 sett+ up vibrations 9 ! b5z5e r+ comp>able ) ^? ( an ela/ic r+ 9 ! act ( exp&+ & contract+4 99 99 99 99 99 ,! l>ge gr\p ( ! ess5tial oils1 conta9+ hydroc>bons simil> to oil ( turp5t9e1 & class$ "u ! g5]ic t]m ( t]p5es1 might1 f _! orig9 & mode ( occurr5ce1 be expect$ to be alli$ 9 con/itution to ! aromatic comp\nds2 & su* is f\nd to be ! case4 ,! t]p5es are isom]ic hydroc>bons ( ! =mula ,c#aj;,h#af4 ,!y are f\nd sometimes s+ly1 at o!r times mix$1 9 a great v>iety ( plants1 associat$ ) sesquit]p5es ,c#ae;,h#bd1 & oxyg5at$ sub/ances1 su* z camphor1 borneol1 m5?ol1 etc41 "s ( :i* h long be5 kn[n & valu$ = _! m$ic9al prop]ties & te*nical applications4 ,! elucidation ( _! con/itution has tax$ ! skill ( _m work]s dur+ ! pa/ ?irty ye>s2 b1 ?anks to ! lab\rs ( ,walla*1 ,baey]1 ,p]k91 ,tiemann1 ,br$t1 ,komppa1 & o!rs1 an insight has be5 ga9$ into _! nature & analogies4 ,!y are app>5tly all cyclic comp\nds ) c]ta9 attributes :i* connect !m ) hydroc>bons ( ! aliphatic s]ies4 ,p95e1 ! *>act]i/ic con/itu5t ( oil ( turp5t9e1 obta9$ by di/ill+ ! res9\s exudations ( _m species ( p9es1 exi/s 9 two modifications1 di/+ui%$ by diff]5ces 9 optical activity1 kn[n respectively z au/ral5e1 f\nd 9 ,am]ican1 ,russian1 & ,sw$i% turp5t9e1 & t]eb5!ne1 f\nd ma9ly 9 ,fr5* turp5t9e4 ,x w\ld seem f _! empirical =mul1 z well z f _! association 9 nature1 t ! t]p5es & camphor1 :i* ,dumas fir/ %[$ to h ! composition ,c#aj;,h#af,o1 %\ld be closely alli$ 9 con/itution1 & t x ought to be readily possible to effect _! mutual trans=mation4 ,! con/itution ( camphor 0 long "o ( ! /&+ problems ( organic *emi/ry1 & doz5s ( =mul h be5 sugge/$ at v>i\s times dur+ ! la/ tw5ty ye>s 9 explanation ( its /ructure4 ,t x conta9$ a b5z5e nucleus seem$ to be prov$ by ! ease ) :i* x yield$ tolu5e1 cym5e1 & o!r b5z5e homologues4 ,! fir/ real insight into its /ructure 0 ga9$ :5 ,br$t asc]ta9$ ! con/itution ( camphoronic acid1 ,c#f;,h#aa 7,,co#b;,h7#d--;a product1 toge!r ) camphoric acid1 ( ! oxidation ( camphor--:i* he f\nd broke up into trime?ylsucc9ic acid & isobutyric acid1 & ! /ructure ( :i* 0 e/abli%$ by ,p]k9 & ,j4 ,f4 ,?orpe4 ,! result ( ! ,japanese monopoly has be5 to greatly enhance ! price ( natural camphor2 dur+ ! la/ t5 ye>s x has practically trebl$4 ,?is has naturally /imulat$ endeav\rs to prep>e ?is sub/ance by syn!tical means4 ,artificial camphor is n[ made f p95e by trans=m+ ! hydroc>bon into bornyl *loride by ! action ( hydro*loric acid4 ,f ?is camph5e is prep>$2 by treatm5t ) glacial acetic acid x =ms isobornyl acetate4 ,on hydrolysis ?is is trans=m$ into isoborneol1 :i* by oxidation yields camphor1 diff]+ f ! naturally occurr+ v>iety only 9 ! fact t x is optically inactive4 ,all s-call$ aromatic comp\nds are n necess>ily cyclic sy/ems1 = x has be5 recognis$ )9 ! pa/ few ye>s t "s ( ! mo/ valuable natural p]fumes1 su* z t ( ! rose1 lav5d]1 & orange blossom1 lemon-grass1 g]anium1 ylang-ylang1 n]oli1 etc41 owe _! *>act]i/ic aroma to ! pres5ce ( t]p5es & camphors1 :i* are n /rictly b5z5oid or cyclic comp\nds1 b 8ruptur$ r+s0 behav+ l op5-*a9 or aliphatic sub/ances4 ,to judge f pa/ exp]i5ce1 x may confid5tly be /at$ t1 n[ ! con/itution ( ^! sub/ances is und]/ood1 _! syn!tical prep>ation on an indu/rial scale is practicable4 ,! discov]y by ,cah\rs 9 #ahdd t oil ( w9t]gre5 is sub/antially me?yl salicylate l$ to its artificial production f syn!tically prep>$ salicylic acid4 ,sir ,william ,p]k9 9 #ahfh effect$ ! syn!sis ( c\m>91 ! aromatic pr9ciple 9 woodruff & hay4 ,fittig & ,mielck 9 #ahfi syn!sis$ heliotrop91 & 9 #ahga ,tiemann & ,ha>mann obta9$ vanill91 ! *>act]i/ic aromatic body 9 ! vanilla pod1 by syn!tic means1 & e/abli%$ its manufacture on a comm]cial scale4 ,! *emical nature ( ! *>act]i/ic odorif]\s sub/ances 9 oil ( cum91 anise1 rue1 c9namon1 heliotrope1 jasm9e1 violet1 p>sley1 etc41 has n[ be5 e/abli%$ & "s ( !m are made indu/rially4 ,! artificial ess5ce ( violets kn[n z ionone1 prep>$ by ,tiemann 9 #ahic1 & n[ made comm]cially1 is simil> b n id5tical 9 /ructure ) ! true p]fume--irone4 ,:at is kn[n z artificial musk is a tr9itro-butyl toluol4 ,artificial orange-fl[] oil is a me?yl e/] ( an?ranilic acid4 ,9 ,vol4 ,i4 a %ort acc\nt has be5 giv5 ( ! e>ly hi/ory ( ! l>ge & important gr\p ( vegetable products kn[n z ! alkaloids4 ,_m ( ^! h long be5 valu$ on acc\nt ( _! p[]ful physiological action4 ,z !y all conta9 nitrog5 & are g5]ally basic1 !y 7 reg>d$ by ,b]zelius1 & subsequ5tly by ,liebig & ,h(mann1 z ak9 to ammonia 9 con/itution1 & 7 class$ z am9es4 ,! fir/ exp]im5tal evid5ce ( _! nature 0 obta9$ by ,g]h>dt1 :o f\nd t1 :5 /ry*n9e & c]ta9 ( ! alkaloids belong+ to ! qu99e gr\p are treat$ ) pota%1 an oil 0 obta9$ :i* he t]m$ qu9ol9e1 & :i* 0 recognis$ by ,h(mann z id5tical ) a sub/ance obta9$ 9 #ahcd f coal-t> by ,runge1 & at t "t kn[n z leucol4 ,by o!r modes ( treatm5t c]ta9 alkaloids--e4g41 nicot9e & con9e--are f\nd to yield pyrid9e1 a basic sub/ance f\nd by ,&]son1 9 #ahdf1 9 ! ftid liquor obta9$ by di/ill+ bones1 & s9ce f\nd 9 coal-t>4 ,o!rs ( !m--e4g41 papav]9e1 n>cot9e1 etc4--yield isoqu9ol9e1 an oil also discov]$ 9 coal-t>1 by ,hoogew]ff1 & ,van ,dorp1 9 #ahhe4 ,^! ?ree sub/ances--qu9ol9e1 isoqu9ol9e1 & pyrid9e--con/itute s _m nuclei 9 ! con/itution ( a l>ge numb] ( alkaloids4 ,pyrid9e resembles b5z5e 9 be+ a cyclic comp\nd1 consi/+ ( five c>bon atoms & "o nitrog5 atom4 ,qu9ol9e /&s to pyrid9e 9 mu* ! same relation t naph?al5e /&s to b5z5e4 ,x c be obta9$ syn!tically1 z fir/ %[n by ,ko5igs & ,skraup1 & subsequ5tly by ,doebn] & ,von ,mill]1 f b5z5e d]ivatives4 ,isoqu9ol9e1 isom]ic ) qu9ol9e1 diff]s f t sub/ance 9 ! position ( ! nitrog5 atom4 ,x1 too1 has be5 syn!tically prep>$ f b5z5e d]ivatives 9 a numb] ( ways4 ,among ! naturally occurr+ pyrid9e alkaloids may be nam$ pip]9e1 f\nd 9 black pepp]1 & con9e1 ! poison\s pr9ciple ( hemlock 7conium maculatum74 ,! latt] alkaloid 0 prep>$ syn!tically by ,lad5burg 9 #ahhf2 z fir/ obta9$ x diff]$ f ! naturally occurr+ product1 :i* is dextro-rotatory1 9 be+ optically inactive4 ,lad5burg surmis$ t ! syn!tic prep>ation /ood to ! naturally occurr+ comp\nd 9 ! same relation t racemic acid /ood to t>t>ic acid1 & t1 by treatm5t 9 ! mann] employ$ by ,pa/eur1 ! racemic modification ( con9e might be sep>at$ into its dextro- & lvo-con/itu5ts4 ,?is 0 f\nd to be ! case2 b ! sep>at$ dextro compon5t 0 n[ f\nd to be di/9ctly m optically active ?an ! pure1 natural v>iety4 ,x 01 9 fact1 an isom]ic modification--iso-con9e4 ,by heat+ ?is to #cjj x 0 trans=m$ into ord9>y con9e1 id5tical 9 all respects ) ! natural alkaloid4 ,lad5burg has also effect$ ! syn!sis ( pip]9e by cond5s+ pip]id9e & pip]9ic acid4 ,nicot9e1 ! alkaloid ( tobacco1 0 discov]$ by ,posselt & ,reimann 9 #ahbh4 ,its con/itution 0 fir/ asc]ta9$ by ,p9n]1 & x 0 syn!tically obta9$ by ,am ,pictet1 9 #aijd1 z an inactive sub/ance1 capable ( be+ resolv$ by ! cry/allisation ( its t>trates into a dextro- & lvo-modification1 ! latt] ( :i* 0 id5tical ) t f\nd 9 ! tobacco leaf4 ,atrop9e & hyoscyam9e--! poison\s pr9ciples ( belladonna & h5bane--are isom]ic alkaloids1 ! =m] ( :i* is optically inactive1 & ! latt] is lvo-rotatory4 ,atrop9e is1 9 fact1 ! racemic modification4 ,! con/itution ( bo? alkaloids is kn[n1 & _! syn!sis is n[ possible4 ,! successive /eps may be ?us indicat$3 #a4 ,syn!sis ( glyc]9 7,f>aday1 ,kolbe1 ,mels5s1 ,bo]have1 ,fri$el1 & ,silva74 #b4 ,glyc]9 to glut>ic acid 7,b]!lot & ,de ,luca1 ,cah\rs & ,h(mann1 ,erl5mey]1 ,l]mant(f1 & ,m>k[nik(f74 #c4 ,glut>ic acid to sub]one 7,br[n & ,walk]1 ,b\ss+ault74 #d4 ,sub]one to tropid9e 7,will/tt]74 #e4 ,tropid9e to trop9e 7,will/tt]1 ,lad5burg74 #f4 ,syn!sis ( tropic acid 7,b]!lot1 ,fittig & ,toll5s1 ,fri$el1 ,lad5burg1 & ,rgheim]74 #g4 ,trop9e & tropic acid3 atrop9e 7,lad5burg74 ,! alkaloid cocane1 conta9$ 9 ! leaves ( ery?roxylon coca & n[ employ$ z a local an/hetic1 0 discov]$ by ,niemann 9 #ahfj4 ,x has be5 %[n to be closely relat$ to atrop9e 9 con/itution1 & has n[ be5 syn!tically prep>$ 9 ! dextro-modification4 ,! alkaloids papav]9e1 n>cot9e1 n>cene1 conta9$ 9 opium1 are d]ivatives ( isoqu9ol9e1 z also is b]b]9e1 f\nd 9 ! common b>b]ry 7b]b]is vulg>is74 ,papav]9e1 :i* occurs 9 opium to ! ext5t ( ab\t "o p] c5t41 0 fir/ isolat$ by ,m]ck 9 #ahdh4 ,its con/itution has be5 e/abli%$ by ,golds*midt4 ,n>cot9e is1 next to morph9e1 ! mo/ abundant con/itu5t ( opium4 ,! /udy ( ! products ( its hydrolysis & oxidation--viz41 opianic acid & cot>n9e1 bo? ( :i* sub/ances h long be5 kn[n--has indicat$ its probable /ructure4 ,n>cene is closely alli$ to n>cot9e1 & c1 inde$1 be obta9$ f x by comb9+ ! latt] alkaloid ) me?yl iodide & treat+ ! comp\nd ) cau/ic pota%4 ,! con/itution ( b]b]9e1 :i* is "o ( ! few col\r$ vegeto-alkaloids kn[n1 has be5 work$ out by ,p]k94 ,z yet no?+ def9ite is kn[n conc]n+ ! /ructure ( ! mo/ important & l>ge/ con/itu5t ( opium--viz41 morph9e2 or ( its cong5]s codene & !ba9e4 ,grimaux1 h[ev]1 9 #ahha conv]t$ morph9e into codene by treatm5t ) me?yl iodide & pota%2 h5ce ! two alkaloids /& 9 a relation some:at simil> to t 9 :i* n>cene /&s to n>cot9e4 ,!re is v little d\bt t ! ?ree alkaloids are v closely relat$1 & t a k ( ! con/itution ( "o ( !m w\ld imm$iately elucidate ! /ructure ( ! o!rs4 ,!y are probably ph5an?r5e d]ivatives4 ,qu99e & c9*on9e1 ! mo/ important ( ! c9*ona alkaloids1 are qu9ol9e comp\nds1 & are closely relat$ 9 con/itution4 ,b ! _m attempts to unravel _! /ructure h yield$ no def9ite results up to ! pres5t4 ,,*apt] ,,ix ,,/]eo-,,isom]ism3 ,,/]eo-,,*emi/ry ,! fir/ grop+s 9 ! se>* = light on ! inn] /ructure ( molecul> gr\p+s may be said to date f ,biot's "w on pol>isation4 ,9 #ahae ,biot1 a pupil ( ,malus1 made ! rem>kable discov]y t a numb] ( naturally occurr+ organic comp\nds--e4g41 sug>1 t>t>ic acid1 oil ( turp5t9e1 camphor1 etc41 are optically active--t is1 rotate ! plane ( pol>isation 9 "o direction or ! o!r4 ,! prop]ty _h previ\sly be5 obs]v$ 9 qu>tz1 & 0 assum$ to be connect$ ) ! cry/all9e "* ( t sub/ance4 ,biot1 h[ev]1 po9t$ out t ! case ( oil ( turp5t9e :i* is a liquid1 & ! cases ( ! o!r sub/ances :5 9 solution1 %[$ t cry/all9e "* _h no necess>y connection ) ! ph5om5on1 b t x mu/ be dep5d5t ^u ! int]nal or molecul> arrangem5t ( ! optically active sub/ance4 ,9 #ahdd ,mits*]li*1 :o fir/ demon/rat$ ! relation betwe5 atomic con/itution & cry/all9e =m1 drew att5tion to ! fact t ! salts ( ! isom]ic modifications ( t>t>ic acid1 /udi$ by ,b]zelius1 al?\gh possess+ ! same *emical composition1 ! same cry/all9e =m1 ) ! same angles1 ! same d\ble refraction1 & !re=e ! same angles betwe5 _! optical axes1 nev]!less behave q diff]5tly z reg>ds _! optical activity1 solutions ( ! t>trates rotat+ ! plane ( pol>isation1 :]eas ^? ( ! racemates are inactive4 ,9 #ahdh ?is rem>kable circum/ance engag$ ! att5tion ( ,l\is ,pa/eur1 a "y man :o _h j complet$ 8 c\rse at ! cole ,normale 9 ,p>is1 & 0 act+ z assi/ant to ,bal>d1 ! discov]] ( ! elem5t brom9e4 ,pa/eur1 on exam9+ ! cry/als ( ! two =ms ( t>t>ic acid1 & ( "s ( _! salts1 detect$ ! pres5ce1 on "s ( !m1 ( c]ta9 facets--s-call$ hemih$ral faces--:i* _h hi!rto be5 unrecognis$1 b 7 simil> to facets :i* ,hay _h obs]v$ on qu>tz4 ,hay _h1 9 fact1 divid$ qu>tz cry/als into two classes--"r-h&$ & left-h&$1 dep5d+ ^u ! side on :i* ^! facets occurr$4 ,! =ms 71 z x is t]m$1 enantiomorph\s4 ,biot1 moreov]1 f\nd t "s qu>tz cry/als1 cut p>allel to ! axis1 turn$ ! plane ( pol>isation to ! "r1 :]eas o!rs turn$ x to ! left2 & ,h]s*el sugge/$ t ! ph5om5a 7 probably connect$1 & su* 0 f\nd to be ! case4 ,m9dful ( ,h]s*el's obs]vation1 ,pa/eur f\nd t ! cry/als ( c]ta9 ( ! optically active t>trates %[$ hemih$ral faces1 :]eas ^? ( ! correspond+ racemates %[$ no trace ( !m4 ,on recry/allis+ ! racemates1 h[ev]1 x 0 notic$ t two sets ( cry/als 7 =m$--enantiomorphic =ms--! fir/ set ( cry/als hav+ hemih$ral =ms on ! "r-h& side1 & ! second set on ! left-h& side4 ,! =ms1 9 fact1 7 s relat$ t "o appe>$1 z if x 7 ! image1 z se5 9 a mirror1 ( ! o!r4 ,:5 solutions ( ^! cry/als 7 exam9$1 "o set 0 f\nd to rotate to ! "r1 ! o!r to an equal degree to ! left4 ,! dextro-rotatory salt yield$ ord9>y t>t>ic acid2 ! correspond+ lvo-rotatory acid 0 a hi!rto unkn[n modification3 ! two toge!r1 9 equal proportions1 con/itut$ racemic acid4 ,9 #ahfc ,wislic5us publi%$ a rem>kable memoir on ! syn!sis ( lactic acid4 ,! acid 9 s\r milk 0 discov]$ by ,s*eele 9 #aghj4 ,9 #ahjg ,b]zelius discov]$ a simil> acid1 call$ s>colactic acid1 9 muscle juice2 ?is 0 errone\sly pron\nc$ by ,liebig to be id5tical ) t ( s\r milk4 ,o!r =ms ( lactic acid 7 made kn[n1 ! /ructural "* ( :i* 0 n to be expla9$ by curr5t hypo!ses4 ,wislic5us conclud$ t _! diff]5ces c\ld be due only to diff]5t arrangem5ts ( _! atoms 9 space4 ,9 #ahgd ! conception ( atomic gr\p+ receiv$ a rem>kable developm5t by ! publication ( two memoirs--"o by ,van 't ,h(f1 & ! o!r by ,le ,bel--:i* s]v$ to connect molecul> /ructure ) optical activity4 ,conf9+ _! att5tion to c>bon comp\nds1 !y inf]r$ t all optically active sub/ances conta9$ at lea/ "o multival5t atom1 unit$ to o!r atoms or gr\ps1 s z to =m 9 space an unsymmetrical arrangem5t4 ,van 't ,h(f reg>d$ ! c>bon atom z occupy+ ! c5tre ( a tetrah$ron1 to ! summits ( :i* its val5cies 7 direct$4 ,if diff]5t gr\p+s are atta*$ to ^! summits1 ! /ructure is asymmetrical1 & is optically active4 ,! two =ms ( lactic acid1 = example1 may be repres5t$ by ! foll[+ space =mul3 ,illu/ration ,x w be se5 f an inspection ( ! figures t ! "o is ! image-=m ( ! o!r1 &1 no matt] h[ !y are turn$1 !y are n sup]posable2 !y are "r- & left-h&$1 or1 z x is t]m$1 enantiomorphs4 ,!re is no fundam5tal di/9ction betwe5 ! hypo!sis ( ,van 't ,h(f & ,le ,bel z to ! effect ( asymmetry on optical behavi\r4 ,le ,bel reg>ds ! effect ( asymmetry simply z a necess>y consequ5ce ( ! pres5ce ( f\r dissimil> gr\p+s1 & z indep5d5t ( val5cy & ! geometrical =m ( ! molecule4 ,illu/ration3 ,,jacobus ,,h5ricus ,,van ',t ,,h(f4 ,x 0 surmis$ by ,pa/eur t e liquid or solid 9 solution %[+ optical activity1 if cry/allisable1 w\ld be f\nd to manife/ hemih$ral faces2 b ?is has n be5 g5]ally e/abli%$4 ,fur!r1 x does n always happ5 t an optically active sub/ance 9 solution is s :5 solid4 ,la/ly1 optical activity may be lat5t ev5 9 asymmetric c>bon comp\nds if dextro- or lvo-modifications are pres5t 9 equal proportions1 z 9 racemic acid4 ,su* comp\nds are1 9 fact1 t]m$ 8racemic10 or racemoids2 & !y may be sep>at$ occasionally by cry/allisation1 z 9 ,pa/eur's me?od ) ! t>trates2 or z %[n by him by ! action ( ! racemoid ^u ano!r optically active sub/ance2 or1 la/ly1 by tak+ advantage ( ! specific action 7specific assimilation7 ( organisms--,pa/eur's s-call$ bio*emical me?od4 ,x is a physiological fact ( great int]e/ t ! behavi\r ( enantiomorphs t[>ds ! animal organism is frequ5tly m>k$ly diff]5t4 ,lvo-t>t>ic acid adm9i/]$ to gu9ea-pigs is f\nd to be twice z poison\s z ! dextro-acid2 dextro-asp>ag9e possesses a sweet ta/e1 b lvo-asp>ag9e is ta/eless2 lvo-nicot9e is m poison\s ?an ! dextro-alkaloid4 ,! f]m5ts kn[n z enzymes are also f\nd to possess ! p[] ( selection1 behav+ diff]5tly t[>ds ! diff]5t optically active modifications ( ! same sub/ance4 ,x is frequ5tly obs]v$ t an optically active sub/ance may be r5d]$ inactive by ! conv]sion ( half ! sub/ance into its enantiomorph4 ,?is op]ation 0 fir/ p]=m$ by ,pa/eur1 & may be br\ght ab\t by heat+ ! sub/ance1 ei!r alone or ) wat]1 "u pressure4 ,inde$1 x is occasionally obs]v$ to take place at ! ord9>y temp]ature 7autoracemisation74 ,by ! action ( v>i\s reag5ts ! d]ivatives ( an optically active sub/ance are f\nd n unfrequ5tly to *ange ! direction ( _! optical activity4 ,inde$1 by su* means "o enantiomorph may be *ang$ into ano!r4 ,?us lvo-m5?ol may be conv]t$ into ! dextro-modification by treatm5t ) sulphuric acid4 ,! rotatory p[] ( a sub/ance is frequ5tly modifi$ by ! "* ( its solv5t1 & v>ies ) ! temp]ature & conc5tration ( ! solution4 ,l&olt & ,oudemans f\nd t ! specific rotation ( dilute solutions ( t>trates & ( salts ( ! active alkaloids 0 indep5d5t ( ! nature ( ! base & acid respectively pres5t--a fact :i* f9ds its explanation 9 ! !ory ( electrolytic dissociation4 ,x has be5 kn[n = "s ye>s pa/ t ! specific rotation ( solutions ( c]ta9 sug>s *anges ) "t1 be+ sometimes less & sometimes m ?an ! initial am\nt4 ,?is ph5om5on is n[ kn[n z multirotation1 or mut>otation4 ,x seems to be connect$ ) an alt]ation 9 ! configuration ( ! molecules4 ,!re is a special case ( /]eo-isom]ism1 diff]+ f t ( optical isom]ism & ( /ructural isom]ism 7) :i* we h hi!rto be5 alone conc]n$71 :i* 0 pr$ict$ by ,van 't ,h(f 9 8 rem>kable "w ,la ,*imie dans l',espace1 publi%$ 9 #ahgg--notewor?y z be+ ! fir/ s]i\s attempt to grapple ) ! problem ( spatial molecul> gr\p+1 =e%ad[$ by ,wolla/on1 ,b]zelius1 &1 inde$1 all ! e>ly philosophic ?9k]s :o accept$ ! atomic !ory4 ,! special =m ( /]eo-isom]ism n[ ref]r$ to1 :i* has be5 m p>ticul>ly inve/igat$ by ,wislic5us1 is di/+ui%$ z geometrical isom]ism2 n1 p]haps1 a suffici5tly descriptive t]m1 s9ce1 compreh5sively1 all =ms ( isom]ism are really cases ( geometrical isom]ism4 ,in/ances ( x are to be met ) among ! isom]ic acids exi/+ z glyc]ides 9 c]ta9 fats1 9 c9namic acid1 9 /ilb5e & its d]ivatives1 etc4 ,x 0 fir/ obs]v$ 9 maleic & fum>ic acids--isom]ic acids ( ! empirical =mula ,c#b;,h#b 7,,cooh7#b1 obta9$ by ! di/illation ( malic acid1 ! *>act]i/ic acid met ) 9 ! apple & o!r fruits & 9 c]ta9 o!r vegetal products4 ,^! acids may be repres5t$ by ! foll[+ space =mul3 ,,cooh----,c----,h ,,cooh----,c----,h ,,cooh----,c----,h ,h----,c----,,cooh ,maleic acid4 ,fum>ic acid4 :i* %[ no asymmetry1 & h5ce no possibility ( optical activity or enantiomorph\s modifications4 ,9 ! case ( maleic acid x w be se5 t ! same gr\ps 7,,cooh or ,h7 are repres5t$ on ! same side ( ! molecule--9 o!r words1 !y are plac$ symmetrically 9 a plane--:]eas 9 fum>ic acid !y are plac$ diagonally or are axially symmetrical4 ,isom]s ( ! fir/ case are classifi$ z mal5oid or cis-=ms1 :ile ^? ( ! latt] are t]m$ fum>oid or trans-=ms4 ,sub/ances ( ! "* ref]r$ to are1 z a rule1 mutually conv]tible ) m or less ease2 !y are susceptible ( :at is call$ geometrical inv]sion4 ,?us fum>ic acid may be readily conv]t$ into maleic acid by heat+2 maleic *loride is gradually trans=m$ into fum>ic *loride at ord9>y temp]atures4 ,sunlight1 or a p>ticul> solv5t1 or ! pres5ce ( "s sub/ance :i* acts z a cataly/1 may effect ! inv]sion4 ,cis & trans isom]ism is also met ) among cyclic comp\nds2 x occurs among ! t]p5es2 & c]ta9 alkaloids1 z1 = example1 cocane1 exhibit x4 ,al?\gh ! doctr9e ( /]eo-*emi/ry 0 fir/ enunciat$ 9 ! case ( c>bon1 & 01 inde$1 = a "t solely conf9$ to comp\nds 9 :i* c>bon 0 ! nucleal elem5t1 !re is no a priori reason :y ! ph5om5on %\ld be s re/rict$4 ,van 't ,h(f1 9 fact1 9 #ahgh1 discuss$ ! "q 9 relation to nitrog5 comp\nds4 ,/]eo-isom]ic nitrog5 d]ivatives 7 fir/ obta9$ by ,victor ,mey] & 8 pupils1 & ! /]eo-*emi/ry ( nitrog5 has s9ce prov$ to be a v fruitful field ( inve/igation1 notably 9 ! h&s ( ,golds*midt1 ,beckmann1 ,hantzs* & ,w]n]1 ,le ,bel1 ,lad5burg1 ,bamb]g]1 ,kipp+1 ,h4 ,o4 ,jones1 ,pope1 & o!rs4 ,! /]eo-*emi/ry ( nitrog5 diff]s f t ( c>bon1 inasmu* z v>iation ( val5cy plays a f> m important "p 9 ! case ( nitrog5 ?an x has hi!rto be5 obs]v$ to d 9 t ( c>bon2 ! spatial repres5tation ( ! trival5t nitrog5 atom diff]s f t ( ! p5taval5t atom4 ,le ,bel1 9 #ahia1 succe$$ 9 obta9+ an optically active nitrog5 enantiomorph by ! application ( ,pa/eur's bio*emical me?od4 ,optically active comp\nds h s9ce be5 prep>$ by ,pope & ,pea*ey & ,h4 ,o4 ,jones4 ,pope & ,pea*ey h also prep>$ optically active comp\nds ( sulphur1 sel5ium1 & t92 & ,kipp+ has obta9$ an asymmetric comp\nd ( silicon4 ,9 #ahfc ,geu!r1 &1 indep5d5tly1 ,frankl& & ,duppa1 made kn[n ! exi/5ce ( aceto-acetic e/]4 ,by ,geu!r ?is comp\nd 0 t]m$ e?yl-di-acetic acid-- ,,*#c4;,c7,,oh73 ,,*cooc#b;,h#e by ,frankl& & ,duppa x 0 consid]$ to be acetone-c>boxylic acid-- ,,*#c4;,,co4,,*#b4;,,cooc#b;,h#e4 ,! ess5tial diff]5ce 9 ^! =mul1 z ! two names respectively indicate1 is t ! fir/ implies t ! e/] has an acidic or hydroxylic "*1 prov$ by its =m+ *>act]i/ic salts2 ! o!r t x conta9s ! gr\p ,,co1 prov$ by its yield+ acetone & ! usual reactions ( ! ketones4 ,! attempt to settle ! con/itution ( ?is sub/ance gave rise to mu* controv]sy1 &1 z x 0 f\nd to be v reactive1 l$ to a great am\nt ( conflict+ exp]im5tal "w4 ,! ultimate result 0 to %[ t bo? =mul are correct3 at ! "t ( reaction ! e/] is sometimes hydroxylic1 at o!r times ketonic1 or1 adopt+ ! t]m9ology ( ,brhl1 x sometimes %[s ! enol =m1 at o!r times ! keto =m4 ,o!r sub/ances 7 subsequ5tly f\nd to behave 9 ! same way4 ,9 #ahhe ! "q 0 discuss$ by ,la>1 :o sugge/$ ! t]m tautom]ism 71 ! same2 1 a "p7 to d5ote ! fact t "o & ! same sub/ance c\ld h /ructural =mul v>y+ ) conditions ( reaction & dep5d+ ^u ! migrations ( c]ta9 ( its atoms )9 ! molecule4 ,dur+ ! la/ tw5ty ye>s a l>ge numb] ( examples ( ! k9d h be5 discov]$4 ,!y are f\nd to occur1 n only among aliphatic sub/ances1 b 9 cyclic & het]ocyclic comp\nds4 ,we n[ "k t su* int]molecul> *anges may occur by ! migration ( any ( ! elem5ts or gr\ps pres5t 9 ! molecule4 ,?us1 to conf9e ourselves to simple & well-kn[n examples1 ! trans=mation ( sodium ph5yl c>bonate into sodium salicylate1 discov]$ by ,kolbe1 is due to ! w&]+ ( an atom ( hydrog5 f ! b5z5e residue to oxyg51 ?us3 ,,oh _/ ,c#f;,h#e4,o4,c,o,o,na,c#f;,h#d ,c,o,o,na4 ,! conv]sion ( ! nitriles into ! cyanides by heat+ is due to ! transf]5ce ( ! alkyl radical f ! nitrog5 atom to ! c>bon-- ,r4,,nc,,nc4,r4 ,alkyl gr\ps may also be transf]r$ f oxyg5 to nitrog52 a radical may deta* itself f a c>bon atom & w&] to a nitrog5 atom2 radicals 9 cyclic comp\nds may be transf]r$ f ! side *a9s to ! nucleus1 etc4 ,! ph5om5on1 9 fact1 is n[ s g5]al t grave d\bts h be5 ?r[n ^u ! uni=m value ( d$uc+ ! /ructural =mula ( a sub/ance f ! /udy ( its decomposition products1 or f ! nature ( its d]ivatives1 ow+ to ! read9ess ) :i* tautom]ism may occur4 ,! *ange may be br\ght ab\t by v>iation ( temp]ature1 by ! reag5t itself1 by ! action ( a solv5t or ! pres5ce ( a cataly/--t is1 ( a sub/ance :i* app>5tly plays no "p 9 ! metamorphosis4 ,h5ce ! value ( specific reag5ts z clues to con/itution is consid]ably weak5$1 s9ce ! results may be equivocal4 ,=tunately1 ! great ext5sion1 )9 rec5t ye>s1 ( ! application ( physical me?ods has consid]ably /r5g!n$ our means ( ga9+ an insight into molecul> /ructure2 & ! inve/igations ( ,brhl on refraction & disp]sion1 ( ,p]k9 on magnetic rotation1 ( ,hantzs* on electrical conductivity1 ( ,l[ry on solubility1 ( ,l[ry & ,e4 ,f4 ,arm/rong on optical activity1 ( ,knorr & ,f9dlay on melt+-po9ts1 &1 la/ly1 ( ,h>tley1 ,dobbie1 ,laud]1 ,baly1 & ,des* on absorption spectra1 h collectively af=d$ valuable in=mation on ! me*anism ( isom]ic *ange bas$ ^u dynamical consid]ations4 ,space w n p]mit ( a m ext5d$ treatm5t ( ! subject ( /]eo-*emi/ry2 & c]ta9 matt]s relat+ to x1 z1 = example1 ! ph5om5a class$ "u ! t]m /]ic h9drance1 mu/ be left unnotic$4 ,?is t]m has ref]5ce to ! h9drance :i* c]ta9 gr\ps1 or ! p>ticul> di/ribution 9 space ( c]ta9 atoms1 ex]t on ! progress or ext5t ( a reaction1 z1 = example1 ( hydrolysis or e/]ification1 etc4 ,! influ5ce ( special gr\p+s 9 ret>d+ *emical *ange is app>5tly well e/abli%$1 b no compreh5sive !ory ( ! subject is yet possible4 ,until su* a !ory is =?com+ a dynamical !ory ( /]eo-*emi/ry is incomplete4 ,,*apt] ,x ,,organic ,,syn!sis3 ,,cond5sation3 ,,! ,,syn!sis ,,( ,,vital ,,products ,9 its wide/ s5se1 ! t]m 8syn!sis10 z us$ 9 organic *emi/ry1 means ! build+-up ( c>bon comp\nds1 ei!r f _! con/itu5t elem5ts or f gr\ps ( diff]5tly con/itut$ molecules4 ,at "o p]iod ?is t]m 0 conf9$ to cases 9 :i* ! organic comp\nd 0 prep>$ f inorganic mat]ials1 or f comb9ations :i* !mselves c\ld be =m$ f _! elem5ts2 b latt]ly x has lo/1 9 l>ge measure1 ?is re/rict$ signification4 ,at ! same "t1 ! attempt has be5 made to indicate by special t]ms c]ta9 classes ( syn!tical reactions4 ,?us ! special case ( ! =mation ( an organic comp\nd by ! union ( two or1 x may be1 m molecul> gr\p+s is n[ frequ5tly spok5 ( z cond5sation4 ,organic *emi/ry has be5 l>gely develop$ by ! discov]y f "t to "t ( special reag5ts & special types ( reactions :i* h %[n !mselves to be capable ( ext5sive application4 ,su*1 = example1 0 ,frankl&'s discov]y1 9 #aheb1 ( z9c-e?yl--! fir/ ( ! organo-metallic comp\nds1 & ! type ( a s]ies ( sub/ances ( great !oretical importance1 & ( great practical value by reason ( _! reactive p[]s4 ,!y l$ to ! syn!sis ( ! p>aff9s1 ! second>y & t]ti>y alcohols1 & ketones4 ,a few ye>s lat] ,wurtz introduc$ ! use ( metallic sodium z a cond5s+ ag5t1 & %[$ !reby h[ ! hydroc>bon butane c\ld be produc$ f e?yl iodide3 #b;,c#b;,h#e;,i ,na#b ,c#d;,h#aj #b,na,i4 ,use 0 made ( ! same ag5t by ,fittig1 9 #ahfc1 9 effect+ ! syn!sis ( ! homologues ( b5z5e by ! action ( an alkyl iodide ^u bromob5z5e3 ,c#f;,h#e;,br ,,*#c;,i ,na#b ,c#f;,h#e4;,,*#c ,na,i ,na,br4 ,9 l mann] ,kekul1 9 #ahff1 obta9$ b5zoic acid by ! action ( c>bon dioxide ^u bromob5z5e3 ,c#f;,h#e;,br ,,co#b ,na#b ,c#f;,h#e;,c,o,o,na ,na,br4 ,! read9ess ) :i* magnesium c n[ be obta9$1 ma9ly z ! result ( ,son/adt's ef=ts to develop its metallurgy1 has l$ to its application1 at ! sugge/ion ( ,b>bi]1 9 #ahii1 9 place ( z9c4 ,! p>ticul> =m ( magnesium comp\nd n[ employ$ z a reag5t 0 prep>$ by ,grign>d 9 #aijj1 & is kn[n by 8 "n4 ,x is obta9$ by br++ an e!real solution ( an alkyl iodide or bromide into contact ) magnesium1 :5 ! metal is dissolv$1 =m+1 9 ! case ( me?yl iodide1 ,mg,c,h#c;,i47,c#b;,h#e7b,o4 ,grign>d's reag5t has %[n itself to be extraord9>ily reactive1 & a great numb] ( cond5sations--( hydroc>bons1 alcohols1 aldehydes1 acids1 ketones1 amides1 & additive comp\nds--h be5 effect$ by means ( x4 ,o!r cond5s+ reag5ts ( value are aceto-acetic e/]1 sodium amalgam1 sodamide1 sodium e?oxide1 dime?yl sulphate1 z9c *loride1 alum9ium *loride1 fus$ cau/ic pota%1 hydrog5 *loride1 ph5yl-hydraz9e1 hydrog5 p]oxide 9 pres5ce ( a f]r\s salt 7,f5ton's reag5t71 ammonia1 & v>i\s am9es4 ,! application ( ^! reag5ts has l$ to ! discov]y ( a v>iety ( new comp\nds1 ! mode ( orig9 ( :i* has s]v$ to elucidate _! con/itution4 ,! great majority ( organic syn!ses1 especially :5 !y />t by ! use ( inorganic mat]ials1 consi/ 9 pass+ f simple to complex molecul> gr\p+s by cond5sation processes4 ,an int]e/+ example ( ! rev]se process is se5 9 ! production ( c>bon suboxide1 or c>bon c>bonyl1 ,c#c,o#b1 obta9$ f v>i\s malonyl comp\nds1 b mo/ conv5i5tly prep>$ by ! action ( phosphoric oxide on malonic acid "u dim9i%$ pressure1 or by treat+ an e!real solution ( dibromomalonyl *loride ) z9c3 ,,cooh ,,co _/ _/_/ 7#a7 ,,*#b #b;,h#b,o ,c ,,cooh ,,co ,,co _/_/ 7#b7 ,c,br#b7;,c,o,cl47#b ,zn#b ,zn,cl#b ,zn,br#b ,c ,,co ,c>bon suboxide is a col\rless1 extremely mobile1 refractive1 poison\s liquid1 ( sp4 gr4 #a4aa1 ) a /rong & peculi> smell4 ,x boils at #g1 & freezes at -#ajg4 ,x is /able only at l[ temp]atures2 at ord9>y temp]atures x polym]ises to a r$ solid1 :i* dissolves 9 wat]1 =m+ a solution ( ! col\r ( eos94 ,! *ange is almo/ in/antane\s at #ajj4 ,c>bon suboxide is inflammable1 burn+ ) a blue b smoky flame3 ,c#c,o#b #b,o#b #c;,,co#b4 ,its l[ boil+-po9t & ! high value ( its molecul> refraction & disp]sion1 its g5]al resemblance to ! metallic c>bonyls & ketones1 etc41 indicate t ?is rem>kable oxide ( c>bon is1 9 all probability1 ! anhydride ( malonic acid4 ,inde$1 by ! action ( wat] ^u x1 x is reconv]t$ into malonic acid4 ,9 po9t ( pr9ciple1 & view$ z *emical op]ations1 ! syn!sis ( vital products is 9 n[ise diff]5t f ! syn!sis ( any o!r gr\p ( organic comp\nds2 & ! special int]e/1 & ev5 a/oni%m5t1 at "o "t creat$ by ! artificial prep>ation ( su* products has l>gely di$ away4 ,! syn!tical production ( "s ( ! sub/ances =m]ly kn[n only to be =m$ by vital action1 ei!r 9 ! animal or ! plant1 has already be5 incid5tally ref]r$ to4 ,b x may be conv5i5t to treat ! subject ( ! artificial production ( ?is gr\p ( bodies r m compreh5sively & z a sub-section ( ?is *apt] on organic syn!sis1 s9ce _! =mation by su* means con/itutes a phase 9 ! developm5t ( *emi/ry1 & has und\bt$ly ex]cis$ a pr(\nd influ5ce on sci5tific ?\ght & on philosophical & ev5 !ological doctr9e4 ,dur+ ! pa/ fifty or sixty ye>s ! *emi/ has be5 enabl$ to =m ! active pr9ciples or *>act]i/ic products ( _m plants & animals4 ,he has built up sub/ances :i* 7 =m]ly reg>d$ z capable ( be+ made only by ! v process ( liv+4 ,he has prep>$ comp\nds :i* 7 at "o "t consid]$ z only producible by *anges 9 organis$ matt] aft] dea?4 ,s9ce ! date ( ,whl]'s epo*-mak+ discov]y1 already ref]r$ to#d urea has be5 syn!tically prep>$ by _m reactions1 notably by ,regnault & ,natanson by ! action ( ammonia on c>bonyl *loride1 & by ,bas>[ & ,dext] f ammonium c>bamate4 ,bo? ^! sub/ances c be =m$ directly or indirectly f _! elem5ts4 ,x may also be obta9$ by ! hydrolysis ( lead cyanate3 ,pb7,,cno7#b #b;,h#b,o ,pb,c,o#c ,,co7,,nh#b7b4 #d ,vol4 ,i41 p4 #afc4 ,! successive /eps 9 its production f inorganic mat]ials by ?is me?od are3 ,k ,c ,n ,,kcn ,,kcno ,pb7,,cno7#b ,,co7,,nh#b7b4 ,associat$ ) urea z products ( metabolism are uric acid1 xan?9e1 & s>c9e4 ,urea 0 fir/ artificially trans=m$ into uric acid by ,horbaczewski1 & its syn!sis 0 effect$ by ,behr5d & ,roos54 ,closely relat$ 9 *emical composition to ^! sub/ances are !obrom9e & caffe9e1 ! *>act]i/ic pr9ciples respectively ( cocoa 7! fruit ( !obroma cacao72 & ( c(fee1 tea1 mat 7! leaves ( ilex p>aguay5sis72 8gu>ana10 obta9$ f ! se$s ( ! ,s\? ,am]ican plant paull9ia sorbilis1 & ! kola-nut ( ,c5tral ,africa4 ,/reck]1 9 #ahfj1 %[$ h[ !obrom9e may be conv]t$ into caffe9e2 & ,emil ,fis*]1 by simil> means1 trans=m$ xan?9e into !obrom9e4 ,s9ce t "t xan?9e itself has be5 prep>$ artificially4 ,caffe9e c n[ be built up f its elem5ts by a s]ies ( trans=mations effect$ by a succession ( *emi/s1 z foll[s3 #a4 ,c>bon & oxyg5 give c>bonic oxide4--,prie/ley1 ,cruick%ank4 #b4 ,c>bonic oxide & *lor9e give c>bonyl *loride4--,j4 ,davy4 #c4 ,c>bonyl *loride & ammonia give urea4--,natanson4 #d4 ,urea gives uric acid4--,horbaczewski2 ,behr5d & ,roos54 #e4 ,uric acid gives xan?9e4--,e4 ,fis*]4 #f4 ,xan?9e gives !obrom9e4--,/reck]4 #g4 ,!obrom9e gives caffe9e4--,e4 ,fis*]4 ,syn!tic !obrom9e is n[ made on ! l>ge scale1 & introduc$ z a soda comp\nd1 9 comb9ation ) sodium acetate1 into m$ic9e z a diuretic "u ! "n ( agur94 ,syn!tic caffe9e is also prep>$ on a manufactur+ scale f uric acid ?r\gh ! m$ium ( ! me?ylxan?9es4 ,! close relation%ip ( xan?9e to uric acid is ( great physiological significance1 s9ce !re is little d\bt t ! xan?9e bases are ! mo/ important s\rces ( uric acid )9 ! organism4 ,9 ?is connection ref]5ce may be made to ! l>ge numb] ( syn!tic organic products :i* h be5 introduc$ into m$ic9e dur+ ! pa/ few ye>s4 ,! inve/igation ( ! con/itution ( ! alkaloids has s]v$ to %[ 9 _m cases to :at p>ticul> molecul> gr\p+ ! physiological action ( ! drug is ma9ly due1 & ?is has l$ to ! production ( sub/ances conta9+ ^! gr\ps1 b n necess>ily exi/+ z natural products4 ,among ^! may be m5tion$ antipyr91 a d]ivative ( ! pyrazol gr\p1 discov]$ by ,knorr 9 #ahhc1 & ( :i* upw>ds ( #ag1jjj kilos1 ( ! approximate value ( #ce1jjj1 7 produc$ 9 #ahii4 ,?is sub/ance is a ph5yl-dime?yl-pyrazolone4 ,acetanilide ,c#f;,h#e,,nh4,,co*#c1 an anil9e d]ivative1 0 discov]$ by ,g]h>dt 9 #ahec4 ,ph5acet9 is a d]ivative ( p>a-am9oph5ol3 ,,oc#b;,h#e _/ ,c#f;,h#d ,,nh4,,co*#c4 ,an extraord9>y numb] ( syn!tical soporifics h be5 introduc$ at v>i\s times dur+ rec5t ye>s--e4g41 *loral hydrate1 v]onal1 sulphonal1 trional & tetronal1 etc4 ,! ?ree la/-nam$ sub/ances are closely relat$1 z ! foll[+ =mul indicate3 ,,*#c ,,*#c ,c7,,s#b;,c#b;,h#e7b ,c7,,s#b;,c#b;,h#e7b _/ _/ ,,*#c ,c#b;,h#e ,sulphonal4 ,trional4 ,c#b;,h#e ,c7,,s#b;,c#b;,h#e7b _/ ,c#b;,h#e ,tetronal4 ,sulphonal is prep>$ by ! oxidation ( a sub/ance obta9$ by ! comb9ation ( acetone & e?ylm]captan4 ,v]onal is an e?yl comp\nd ( b>bituric acid1 obta9$ by ! cond5sation ( urea & die?yl malonyl *loride3 ,,nh4,,co _/ ,,co ,c7,c#b;,h#e7b _/ ,,nh4,,co ,v]onal4 ,attempts h be5 made to connect ! physiological work+ ( local an/hetics ) p>ticul> con/itutional gr\p+s1 z1 = example1 9 cocane2 & ^! h l$ to ! introduction ( su* sub/ances z ! or?(orms1 nirvan9e1 /ovane1 alyh9e1 novocane1 & adr5al9e into m$ic9e4 ,adr5al9e1 us$ 9 conjunction ) cocane1 has prov$ itself a mo/ valuable ag5t 9 produc+ :at is call$ lumbal an/hesia1 :]eby l>ge sections ( ! l[] half ( ! body may be r5d]$ completely ins5sitive to pa94 ,! /udy ( ! putrefactive *anges ( album9\s sub/ances ( animal orig91 induc$ by ! activity ( micro-organisms1 has reveal$ ! exi/5ce ( a numb] ( basic nitrog5\s comp\nds1 "s ( :i* are highly poison\s4 ,^! 7 class$ by ,selmi "u ! g5]ic "n ( ptoma9es 71 a corpse74 ,brieg] f\nd t ! typhoid bacillus yield$ a poison\s sub/ance--typhotox9e1 & t ! bacillus ( tetanus =ms a highly toxic basic body1 tetan9e4 ,all ! ptoma9es1 h[ev]1 are n poison\s4 ,"s ( !m1 l *ol9e 71 bile7--orig9ally discov]$ by ,/reck] 9 bile1 9 ! bra91 9 yolk ( egg1 & n[ f\nd to be among ! products ( ! putrefaction ( meat & fi%--h be5 kn[n = "s "t pa/4 ,*ol9e 0 fir/ syn!tically prep>$ by ,wurtz4 ,neur9e 71 n]ve71 a d]ivative ( bra9 sub/ance1 is relat$ to *ol9e1 & is readily trans=m$ into x1 b diff]s f x 9 be+ v poison\s4 ,x has be5 syn!sis$ by ,h(mann & by ,baey]4 ,ano!r ( ! s-call$ corpse-alkaloids--cadav]9e--has be5 syn!tically =m$ by ,lad5burg4 ,s*mi$eb]g & ,kopp isolat$ ! poison\s pr9ciple ( ! fungus ag>icus musc>ius1 :i* !y nam$ musc>9e4 ,x occurs ) *ol9e1 f :i* x c be readily obta9$1 among ! products ( ! putrefaction ( fle%1 z well z 9 _m fungi4 ,! syn!sis ( ! alkaloids con9e1 atrop9e1 cocane1 pip]9e1 & nicot9e has be5 already ref]r$ to#e z also t ( vanill91 ! aromatic pr9ciple ( ! dri$ f]m5t$ pods ( c]ta9 or*ids2 c\m>91 ! odorif]\s pr9ciple ( woodruff & ( ! tonka bean2 ( salicylic acid1 oil ( w9t]gre51 oil ( mu/>d1 bitt]-almond oil1 & camphor4 ,acetic1 succ9ic1 t>t>ic1 & citric acids h also be5 artificially obta9$1 & may1 inde$1 be built up f _! elem5ts4 #e ,p4 #acc4 ,no syn!sis ( rec5t ye>s creat$ m widespread int]e/ ?an t ( aliz>91 fir/ effect$ by ,graebe & ,lieb]mann 9 #ahfh4 ,its successful comm]cial manufacture by ,sir ,william ,p]k9 9 ?is c\ntry & by ,c>o 9 ,g]many creat$ no?+ less ?an a revolution 9 "o ( our lead+ indu/ries1 & completely de/roy$ a /aple trade ( ,france1 ,holl&1 ,italy1 & ,turkey4 ,to procure aliz>91 an?raqu9one is treat$ ) sulphuric acid1 & ! product is fus$ ) alkali & potassium *lorate4 ,! rem>kable indu/rial results att5d+ ! syn!tical =mation ( ?is madd]-product naturally l$ to attempts to procure o!r important vegetable dye-/uffs artificially1 notably indigo4 ,! syn!tical production ( indigo has be5 accompli%$ by ! jo9t lab\rs ( _m *emi/s1 notably ,baey]1 ,heumann1 & ,heymann1 & ! sub/ance is n[ prep>$ on an indu/rial scale4 ,! />t+-po9t is naph?al5e1 obta9$ f coal-t>4 ,?is is conv]t$ into ph?alic acid1 :i* is !n trans=m$ into ph?alimide4 ,! la/-nam$ sub/ance is conv]t$ into an?ranilic acid1 :i*1 on treatm5t ) mono*loracetic acid1 is *ang$ into ph5ylglyc9-or?o-c>bonic acid4 ,on melt+ ?is ) cau/ic pota% x yields indoxyl acid1 :i* is trans=m$ into indoxyl1 & !nce into indigo4 ,ano!r me?od is to treat ! sodium salt ( ph5ylglyc9 ) sodamide1 :]eby indoxyl is at once obta9$1 & ?is by cond5sation yields indigo blue3 ,c#f;,h#e4,,nh4,,*#b4;,c,o,o,na ,na4,,nh#b ,sodium salt ( ,sodamide4 ph5ylglyc94 ,,co _/ ,c#f;,h#d ,,*#b _/ ,,nh ,indoxyl4 ,,co ,,co _/ _/ ,c#f;,h#d ,c3,c ,c#f;,h#d _/ _/ ,,nh ,,nh ,indigo blue4 ,ph5ylglyc9 is obta9$ by ! action ( mono*loracetic acid on anil9e1 :i* 9 its turn is obta9$ ?r\gh nitrob5z5e f b5z5e4 ,s9ce b5z5e c be syn!tically prep>$ by ! cond5sation ( acetyl5e1 :i* c be obta9$ by ! direct union ( c>bon & hydrog5 at a high temp]ature1 x is !oretically possible to build up indigo blue f inorganic mat]ials4 ,syn!tical indigo blue 0 plac$ on ! m>ket 9 #ahig ) an almo/ imm$iate effect on ! production & price ( ! natural v>iety1 & to-day ! output ( ,b5gal indigo has fall5 by m ?an fifty p] c5t4 ,9 #aijb ! am\nt ( ! natural product 0 probably n great] ?an ?ree million kilos1 :]eas 9 ! same ye> ! production ( syn!tic indigo 0 upw>ds ( five million kilos4 ,be=e ! introduction ( ! artificial v>iety ! price ( pure indigo blue rang$ f sixte5 to tw5ty %ill+s p] kilo2 by ! end ( #aije x _h fall5 to sev5 or eight %ill+s4 ,m5tion %\ld be made also ( ?io-indigo r$ & ! ?ionaph!ne d]ivatives1 "s ( :i* promise to be important col\r+ matt]s4 ,9 rec5t ye>s ! s-call$ sulphur col\r+ matt]s h acquir$ consid]able importance4 ,space w n p]mit ( any full] treatm5t ( ! developm5t ( ! manufacture ( ! artificial organic col\r+ matt]s4 ,?is indu/ry _h its beg9n+s 9 ,engl&1 b x is n[ ma9ly c>ri$ on 9 ,g]many4 ,its importance may be glean$ f ! fact t ! value ( ! production at ! pres5t "t am\nts to n less ?an #ab1ejj1jjj p] annum1 two ?irds ( ! output be+ export$4 ,x dem&s ! s]vices ( battalions ( skill$ *emi/s1 & gives employm5t to _m ?\s&s ( artisans4 ,"s ( ! mo/ notable a*ievem5ts ( mod]n syn!tical *emi/ry are to be f\nd 9 ! "w ( ,emil ,fis*] on ! sug>s & ! prote9s4 ,al?\gh ! sug>s h f ! e>lie/ times be5 reckon$ among ! mo/ *>act]i/ic products ( plant life1 & h long be5 us$ z food & z s\rces ( alcohol1 comp>atively little 0 kn[n until lately ( _! real nature & mutual relations1 9 spite ( num]\s attempts to elucidate _! con/itution4 ,mu* ( ! my/]y surr\nd+ _! *emical hi/ory has n[ be5 dispell$4 ,n only has ! molecul> /ructure ( ! m important naturally occurr+ sug>s be5 unravell$1 b a l>ge numb] ( hi!rto unkn[n memb]s ( ! v>i\s gr\ps ( ! great family to :i* !y belong h be5 prep>$4 ,! fir/ insight into ! con/itution ( ^! bodies may be said to date f ! rese>*es ( ,kiliani1 made ab\t a qu>t] ( a c5tury ago4 ,9 #ahhg ,fis*] effect$ ! syn!sis ( a =m ( fructose 7fruit sug>71 & imm$iately aft]w>ds ( ord9>y dextro-glucose 7grape sug>7 & its enantiomorph lvo-glucose1 & ! two optically active =ms ( natural fruit sug>4 ,s9ce t "t su* sug>s z arab9ose1 xylose1 fucose1 mannose1 sorbose1 cane-sug>1 maltose1 lactose1 etc41 & ! sug>s exi/+ z glucosides1 h be5 exam9$1 _! /]eo-*emical relations def9$1 & syn!tic me?ods ( production devis$4 ,incid5tally1 _! behavi\r t[>ds enzymes has be5 /udi$1 & ! rem>kable selective action ( ^! f]m5ts on ! v>i\s gr\ps1 due app>5tly to diff]5ces ( configuration1 has be5 e/abli%$1 ) ! result t mu* light has be5 ?r[n on ! me*anism ( enzyme action & on ! g5]al !ory ( f]m5tation4 ,illu/ration3 ,,emil ,,fis*]4 ,! /udy ( ! prote9s by ,fis*] con/itutes a new *apt] 9 bio-*emi/ry4 ,al?\gh long recognis$ z among ! mo/ important ( vital products1 f ! circum/ance t !y ent] into ! composition ( animal tissues & secretions & are ess5tial con/itu5ts ( protoplasm1 ! prote9s are among ! wor/ def9$ sub/ances kn[n to ! *emi/4 ,!y are difficult to sep>ate1 z !y closely resemble "o ano!r1 & af=d no c]ta9 indications ( individuality4 ,v few ( !m h be5 obta9$ 9 a =m 9 :i* _! id5tity c\ld be e/abli%$4 ,oxyhmoglob9 0 isolat$ "s ye>s ago1 b ! prote9s ( s]um album9 & ( egg album9 h only rec5tly be5 obta9$ 9 def9ite cry/all9e %ape4 ,all ! prote9s--ev5 ! simple/ ( !m--are ( great complexity1 & possess app>5tly v high molecul> weights4 ,hmoglob91 = example1 appe>s to h approximately ! =mula ,c#aeh;,h#abc,n#aie,o#bah;,fe,s#c1 ) a m9imum molecul> weight ( #af1fjj4 ,inde$1 !re is exp]im5tal evid5ce to %[ t x is ev5 consid]ably high] ?an ?is4 ,! ma9 clues to ! nature ( ^! sub/ances h be5 ga9$ by ! sy/ematic /udy ( _! hydrolysis1 induc$ by reag5ts1 or by ! action ( enzymes1 :]eby !y are f\nd to break d[n into proteoses1 peptones1 & a great v>iety ( am9o acids1 "s ( :i* h be5 syn!sis$4 ,among ! prote9s ( simple/ con/itution are ! protam9es1 f\nd 9 ! sp]matozoa ( fi%4 ,!y are basic sub/ances1 especially ri* 9 nitrog51 =m+ salts ) plat9um *loride & c]ta9 metallic oxides4 ,! be/ inve/igat$ memb] ( ! gr\p is salm9e1 obta9$ f ! te/icle ( ! salmon4 ,! products ( its hydrolysis h be5 fairly well asc]ta9$1 & _! quantitative relation is su* t ! sub/ance mu/ h at lea/ a molecul> weight ( #bjde1 correspond+ to ! =mula ,c#ha;,h#aee,n#de,o#ah4 ,_m ( ! album9s & globul9s--coagulable prote9s conta9$ 9 ! animal tissues--h be5 isolat$ 9 a m or less def9ite =m1 & "s ( !m h be5 f\nd to yield sub/ances ak9 to c>bohydrates4 ,?yreoglobul91 ! globul9 ( ! ?yroid gl&1 has be5 f\nd to conta9 iod9e1 app>5tly z a normal con/itu5t ( a body :i* c be isolat$ z a def9ite proximate pr9ciple4 ,! pres5ce ( ?is elem5t is possibly connect$ ) ! curative value ( ! globul9 9 crt9ism4 ,a consid]able am\nt ( "w on ! vegetable album9s has also be5 done ( late ye>s2 & "s ( !m1 z ede/9 f hemp se$ & ze9 f maize1 h be5 obta9$ 9 def9ite =m4 ,! limits ( ?is "w preclude a m detail$ acc\nt ( "o ( ! mo/ int]e/+ b at ! same "t "o ( ! mo/ obscure dep>tm5ts ( *emi/ry4 ,! field has hi!rto be5 till$ 9 a some:at int]mitt5t & p>tial mann]4 ,n[ t x has be5 ent]$ by *emi/s ( exp]i5ce & res\rcefulness1 arm$ ) mod]n me?ods ( cultivation1 x w d\btless soon yield a ri* h>ve/ ( facts1 valuable alike to ! physiologi/ & ! physician4 ,!re c be no reasonable d\bt t ! *emical processes ( organic life are ess5tially simil> to ^? ( ! laboratory4 ,! doctr9e t a special 8vital =ce0 is conc]n$ 9 ! production ( vital products receives no support f ! tea*+ ( mod]n sci5ce1 & is1 inde$1 contradict$ by x4 ,at ! same "t1 x mu/ be admitt$ t we "k v little z yet ( ! real ag5cies at "w 9 ! elaboration & mutations ( *emical products 9 ! liv+ organism4 ,because we h effect$ ! putt+ toge!r ( su* a product by purely laboratory processes--x may be1 inde$1 by a v>iety ( diff]5t & dissimil> processes--x by no means foll[s t any "o ( !m is id5tical ) t actually occurr+ 9 nature4 ,! build+ up ( mat]ials 9 ! plant by ! ag5cy ( light1 = example1 has n yet be5 imitat$ 9 ! laboratory4 ,_m plant products are produc$ by ! action ( unorganis$ f]m5ts--s-call$ enzymes--none ( :i* ! *emi/ has succe$$ 9 creat+4 ,processes ak9 to cond5sation und\bt$ly occur 9 ! liv+ organism2 b ! means by :i* !y are effect$ are1 9 all probability1 v diff]5t f any?+ kn[n to ! *emi/ at pres5t4 ,_m laboratory cond5sations are only accompli%$ at relatively high temp]atures or "u consid]able pressure--or1 9 o!r words1 "u totally diff]5t conditions f ^? :i* obta9 9 ! organism4 ,,*apt] ,,xi ,,on ,,! ,,developm5t ,,( ,,physical ,,*emi/ry ,,s9ce #ahej ,*emi/ry & physics are ea* complem5t>y to ! o!r3 t region ( inquiry 9 :i* !y mutually ov]lap is kn[n z physical *emi/ry4 ,its beg9n+s are practically contemporane\s ) ^? ( *emi/ry itself4 ,its ma9 developm5t has occurr$1 h[ev]1 dur+ ! la/ tw5ty-five ye>s4 ,c]ta9 ( its lead+ features h be5 ref]r$ to already 9 connection ) ! e/abli%m5t ( ! fundam5tal pr9ciples ( *emi/ry1 ! explanation ( ! s-call$ gase\s laws1 ! con/itution ( gases1 ! relations ( _! volumes to heat & pressure1 & ! conditions affect+ _! transition to ! liquid /ate4 ,z reg>ds ! molecul> volumes ( gases x has be5 %[n t simple relations are obta9$ :5 quantities repres5t$ by _! respective molecul> weights are comp>$ "u id5tical conditions ( temp]ature & pressure--t is1 "u circum/ances 9 :i* equal numb]s ( molecules =m ! basis ( comp>ison4 ,! inve/igation ( ! molecul> volumes ( liquids is complicat$ by ! unc]ta9ty z to :at con/itutes 9 _! case a valid condition ( comp>ison4 ,kopp's assumption t a comp>able condition 0 ! temp]ature at :i* ! vap\r pressures ( ! liquids are equal to ! mean atmosph]ic pressure 0 ju/ifi$ by ! fact t ! boil+-po9ts ( liquids are approximately two ?irds ( _! respective critical temp]atures4 ,8 conclusions h be5 confirm$ & ext5d$ by ,loss51 ,?orpe1 & ,s*iff4 ,x has be5 %[n t ! molecul> volume ( a liquid--t is1 ! product ( its relative d5sity at ! boil+-po9t into its molecul> weight--is 9 ! ma9 an additive function modifi$ by con/itutive influ5ces4 ,def9ite values h ?us be5 obta9$ = a numb] ( ! elem5ts f a comp>ison ( homolog\s or simil>ly con/itut$ comp\nds2 & 9 c]ta9 cases ^! are f\nd to be practically id5tical ) ! values ( ! elem5ts 9 ! uncomb9$ /ate4 ,consid]able light has be5 ga9$ dur+ ! la/ two decades conc]n+ ! nature ( solution4 ,9 its mo/ compreh5sive s5se solution means ! homog5e\s mixture ( two or m sub/ances3 ?us ! gases :i* ex]t no *emical action on ea* o!r are mutually soluble2 gases1 liquids1 & solids may be soluble 9 liquids2 &1 la/ly1 solids maybe soluble 9 solids1 =m+ :at are kn[n z solid solutions4 ,! mutual solubility ( gases 0 /udi$ by ,dalton :o enunciat$ ! law ( p>tial pressures1 :i* /ates t ! total pressure ( a mixture ( gases is ! sum ( ! pressures ex]t$ by ! individual compon5ts4 ,?is1 l all ! s-call$ gase\s laws1 is necess>ily n /rictly accurate "u ord9>y conditions1 b approximates to tru? 9 proportion z ! gases are r>efi$4 ,van 't ,h(f po9t$ out t ! true p>tial pressures ( ! compon5ts ( a gase\s mixture might be exp]im5tally asc]ta9$ by ! use ( a membrane capable ( effect+ _! sep>ation1 & on ?is pr9ciple ,ramsay measur$ ! p>tial pressures ( a mixture ( hydrog5 & nitrog5 conta9$ 9 a palladium vessel connect$ ) a manomet]4 ,! palladium1 at a suffici5tly high temp]ature1 is p]meable to hydrog5 to ! exclusion ( ! nitrog54 ,! conditions affect+ ! solubility ( gases 9 liquids 7 exp]im5tally /udi$ by ,dalton & ,h5ry1 & :at is kn[n z ,h5ry's law implies t ! volume ( a gas dissolv$ by a def9ite volume ( a liquid is indep5d5t ( ! pressure2 or1 9 o!r words1 ! d5sity 7conc5tration7 ( ! gas 9 solution is proportional to t 9 ! space above ! liquid4 ,gases are dissolv$ by liquids 9 v diff]5t am\nts1 b no?+ def9ite is kn[n z yet conc]n+ ! relation betwe5 ! nature ( ! gas & its solubility1 al?\gh c]ta9 broad g5]alisations are possible4 ,?us neutral gases--e4g41 hydrog5 & nitrog5--are sp>+ly soluble1 :]eas gases :i* %[ acidic or basic prop]ties1 su* z ! hydrog5 halides1 etc41 ammonia1 etc41 are freely soluble4 ,easily liquefiable gases are also comp>atively soluble z not$ by ,graham4 ,comp>atively little is kn[n def9itely conc]n+ ! conditions ( solubility ( liquids 9 liquids4 ,"s liquids are :olly1 o!rs p>tially miscible2 & temp]ature & pressure appe> to affect ! proportions 9 :i* ! compon5ts =m a homog5e\s mixture4 ,z reg>ds ! solubility ( solids 9 liquids1 our k is m ext5sive1 & a consid]able body ( lit]ature exi/s on ! subject1 *iefly conc]n+ solubility ( solids 9 wat]4 ,! solubility ( a solid dep5ds on ! temp]ature ( ! solv5t1 &1 z a rule1 increases ) ! temp]ature until a c]ta9 am\nt ( ! solid has be5 dissolv$1 :5 ! solution is said to be saturat$4 ,if ! cle> saturat$ solution be sl[ly cool$1 say1 to a p>ticul> temp]ature1 x is frequ5tly obs]v$ t m ( ! solid rema9s 9 solution ?an is normal to t temp]ature2 su* a solution is said to be sup]saturat$4 ,on add+ "s ( ! solid to ! sup]saturat$ solution ! excess ( ! solute is precipitat$4 ,9 c]ta9 cases ( solubility ( sub/ances 9 wat]1 increase ( temp]ature appe>s to dim9i% ! am\nt dissolv$4 ,9 ne>ly all su* cases ! diff]5ce 9 solubility is due to diff]5ces 9 ! hydration ( ! solute4 ,! ph5om5a ( solid solutions h be5 less p]fectly inve/igat$1 b ! facts appe> to %[ t su* solutions 9 g5]al t5d to obey ! laws regulat+ ! solution ( liquids 9 liquids4 ,alloys may be look$ ^u z solid solutions2 & ,rob]ts-,au/5 has %[n t metals are capable ( intradiffusion1 l liquids & gases respectively4 ,! g5]al "q ( solution 0 greatly develop$ 9 #ahhe by ,van 't ,h(f1 by specially consid]+ ! case ( dilute solutions4 ,! gase\s laws are capable ( _! simple/ expression :5 ! gases are r>efi$ to su* an ext5t t _! molecules ex]t no s5sible mutual influ5ce4 ,! case ( dilute solutions is analog\s4 ,if ! solute is pres5t only 9 v small am\nt1 ! mutual influ5ce ( its molecules is practically negligible4 ,"u su* conditions x obeys ! laws hi!rto suppos$ to be applicable only to matt] 9 ! gase\s /ate4 ,x may be desirable to expla9 h[ ?is fundam5tal fact 0 recognis$4 ,x has long be5 kn[n to ! physiologi/ t c]ta9 membranes are semi-p]meable--t is1 !y all[ ( ! passage ( c]ta9 liquids1 & ( sub/ances 9 solution1 to ! exclusion ( o!rs4 ,?is ph5om5on is t]m$ osmosis1 & is ( great biological significance4 ,x 0 fir/ /udi$ by plant-physiologi/s1 notably by ,traube & ,pfeff]4 ,_m su* semi-p]meable membranes c be =m$ artificially1 b ! mo/ g5]ally conv5i5t is f\nd to be "o consi/+ ( copp] f]rocyanide deposit$ on ! walls ( a por\s vessel4 ,if a vessel s prep>$ be fill$ ) a solution ( sug>1 & be !n plac$ 9 wat]1 ! wat] is f\nd to pass ?r\gh ! membrane1 b ! membrane is imp]meable to ! sug>4 ,9 consequ5ce pressure1 t]m$ osmotic pressure1 is f\nd to occur )9 ! pot1 & may be measur$ by suitable means4 ,^! osmotic pressures may at times be v l>ge3 ?us a #a p] c5t4 solution ( sug> may ex]t a pressure ( half an atmosph]e1 & 9 ! case ( a solution ( potassium nitrate ( ! same conc5tration x may am\nt to a c\ple ( atmosph]es4 ,pfeff] det]m9$ ! relation ( ! osmotic pressures to ! conc5tration ( solutions ( ^! sub/ances1 measur+ ! pressures 9 c5timetres ( m]cury by a manomet] atta*$ to ! clos$ por\s vessel4 ,8 results 9 ! case ( sug> 7 z foll[s3 ,p]c5tage ,pressure 9 cm4 /r5g? 7,c74 ( m]cury 7,p74 ,p_/,c4 #a #ec4e #ec4e #b #aja4f #ej4h #d #bjh4b #eb4a #f #cjg4e #ea4c ,x w be se5 f ^! numb]s t ! ratio ,p_/,c is practically con/ant--t is1 ! osmotic pressure v>ies directly z ! conc5tration4 ,x 0 fur!r f\nd t ! osmotic pressure ex]t$ by a solution ( uni=m /r5g? increases ) ! temp]ature4 ,! importance1 ( ^! obs]vations 9 relation to ! g5]al !ory ( solution 0 fir/ recognis$ by ,van 't ,h(f4 ,osmotic pressure 0 reg>d$ by him z analog\s to gase\s pressure4 ,s9ce ,p_/,c is con/ant = any "o sub/ance1 & s9ce = a def9ite weight ( ! solute ! conc5tration is inv]sely z ! volume ( ! solution1 we obta9 an equation analog\s to ! /atem5t ( ,boyle's law1 ,,pv con/ant4 ,van 't ,h(f also f\nd t ! osmotic pressure is proportional to ! absolute temp]ature1 l ! gase\s pressure4 ,f ^! results1 9 conjunction ) ,avogadro's hypo!sis1 x foll[s t ! osmotic pressure ex]t$ by any sub/ance 9 solution is ! same z x w\ld ex]t if pres5t z gas 9 ! same volume z t occupi$ by ! solution1 provid$ t ! solution is s dilute t ! volume occupi$ by ! solute is negligible 9 comp>ison ) t occupi$ by ! solv5t4 ,ano!r important consequ5ce is t solutes1 :5 pres5t 9 ! ratio ( _! molecul> weights 9 equal volumes ( ! same solv5t1 ex]t ! same osmotic pressure4 ,su* solutions are said to be isomotic or isotonic4 ,x c be prov$ by !rmodynamical reason+ t depression ( ! vap\r pressure & freez+-po9t ( a solution is proportional to its osmotic pressure4 ,! significance ( ?is relation 9 connection ) ! det]m9ation ( ! molecul> weight ( a soluble sub/ance has already be5 ref]r$ to4#f #f ,see pp4 #gj-gc4 ,det]m9ations ( molecul> freez+-po9t depressions by ,ra\lt & o!rs %[$ t c]ta9 sub/ances ex]t$ only ab\t half ! osmotic pressure calculat$ f _! kn[n =mul1 :]eas o!rs h abnormally high osmotic pressures4 ,! explanation ( ! discrepancies 9 ! latt] case 0 giv5 9 #ahhg by ,arrh5ius1 :o po9t$ out t only ^? solutions :i* h abnormally high osmotic pressures are electrically conductive4 ,?is pregnant obs]vation prov$ to be v fruitful 9 sugge/iv5ess2 & ! connection betwe5 conductivity & ,van 't ,h(f's !ory ( solution 0 develop$ by ,arrh5ius into ! doctr9e ( electrolytic dissociation or ionisation--"o ( ! mo/ important consequ5ces ( ,f>aday's electrolytic laws1 ! "w ( ,hittorf1 & ! k9etic conceptions ( ,williamson & ,clausius to :i* ! la/ qu>t] ( a c5tury has giv5 rise4 ,arrh5ius %[$ t n only 7 free ions pres5t 9 an electrically conductive solution be=e electrolysis1 z ma9ta9$ by ,clausius1 b t ! proportion ( molecules dissociat$ into ions c\ld be calculat$ f measurem5ts ( electrical conductivity1 z well z f measurem5ts ( osmotic pressure4 ,bo? me?ods give concordant results--a /rong confirmation ( ! validity ( ! !ory4 ,9 a solution ( common salt1 conta9+ a gramme equival5t ( t sub/ance 9 a litre1 ,arrh5ius calculat$ t only ab\t ?ree t5?s ( ! salt exi/s z ,na,cl1 ! rema9+ sev5 t5?s be+ resolv$ into indep5d5t ions ( *lor9e 7*loridion7 & sodium 7sodion73 ,na,cl,na ,cl1 ea* mov+ freely 9 all directions1 l gase\s molecules4 ,on pass+ ! curr5t1 electrodes plac$ 9 ! solution ex]t a directive action on ! free ions1 ^! alone be+ conc]n$ 9 det]m9+ ! conductivity1 ! un-ionis$ molecules or ! solv5t itself ex]cis+ no influ5ce4 ,me?ods ( det]m9+ ! migration velocity ( ! ions h be5 work$ out by ,hittorf1 ,kohlraus*1 ,lodge1 & o!rs4 ,illu/ration3 ,,svante ,,augu/ ,,arrh5ius4 ,! !ory ( ionisation af=ds a satisfactory explanation ( _m *emical ph5om5a4 ,x acc\nts = ! *>act]i/ic prop]ties ( acids1 & expla9s :y diff]5t acids h v>y+ 8/r5g?s0 & :y a 8weak0 acid has ! same 8/r5g?0 z ! 8/rong0 acid at high equival5t dilutions3 9 ea* case ! acid is ne>ly completely ionis$--9 o!r words1 ! 8/r5g?0 ( an acid dep5ds on ! conc5tration ( its hydrog5 ions4 ,s1 too1 ! 8/r5g?0 ( a base is relat$ to ! numb] ( its hydroxyl ions4 ,aque\s ammonia is relatively a 8weak0 base--its solution conta9s few hydroxyl ions4 ,on ! o!r h&1 cau/ic pota% is a 8/rong0 base--its solution1 on mod]ate dilution1 is almo/ completely ionis$3 ,,koh ,k ,,oh1 ! positive ion be+ repres5t$ by "o or m dots1 & ! negative ion by "o or m da%es4 ,! !ory acc\nts1 too1 = _m ph5om5a 9 analytical *emi/ry--su* z :y magnesia is precipitat$ by ammonia only 9 ! abs5ce ( ammonium *loride1 & :y sulphurett$ hydrog5 ?r[s d[n z9c sulphide 9 ! abs5ce ( hydro*loric acid4 ,x also s]ves to expla9 _m !rmo-*emical facts obs]v$ by ,hess1 ,?oms51 & o!rs1 su* z ! fact t ! heat ( neutralisation ( ! 8/rong0 acids & bases is indep5d5t ( _! nature1 & has ! uni=m value ( #ac1gjj calories1 9 agreem5t ) ! value1 z calculat$ by ,van 't ,h(f1 = ! reaction ,h ,,oh ,h#b,o1 d$uc$ f ,kohlraus*'s measurem5ts ( ! conductivity ( wat] at v>y+ temp]atures4 ,c]ta9 ph5om5a relative to ! effect ( conc5tration 7mass action7 9 det]m9+ *emical *ange--_m ( :i* h be5 /udi$ by ,o/wald & 8 pupils1 z1 = example1 :y two dilute solutions c be mix$ toge!r )\t !rmal di/urbance2 num]\s hydrolytic actions2 ! alkal9ity & acidity ( salts on solution2 ! behavi\r ( ! 8indicators0 9 analysis2 su* ph5om5a z ! precipitability ( common salt 9 aque\s solution by hydrog5 *loride2 ! influ5ce ( an excess ( a precipitant2 ! v>y+ behavi\r ( reag5ts2 ! v>y+ col\r ( salt solutions2 ! reason :y wat] is =m$ 9 s _m reactions2 :y a pot5tial diff]5ce occurs at ! surface ( two electrolytic solutions1 etc4--ph5om5a = ! mo/ "p o!rwise un9telligible1 are all capable ( explanation by means ( x4 ,al?\gh1 9 ! above /atem5t1 we h be5 ma9ly conc]n$ ) aque\s solutions1 x %\ld be said t ! !ory ( ionisation is applicable to o!r solv5ts1 organic & inorganic4 ,moreov]1 x %\ld be add$1 ! !ory has n be5 univ]sally accept$ z acc\nt+ = all ! ph5om5a ( solution4 ,_m sub/ances =m def9ite hydrates :i* c be isolat$1 & x is a moot po9t :e!r su* hydrates are capable ( exi/+ 9 aque\s solution1 z cont5d$ by ,m5deleff1 ,pick]+1 ,kahl5b]g1 ,arm/rong1 & o!rs4 ,su* hydrates are1 h[ev]1 un/able comp\nds1 affect$ by temp]ature *anges1 & dissociable on dilution 9 accordance ) ! law ( conc5tration 7mass action74 ,fur!r1 !re is evid5ce1 l>gely bas$ on ! "w ( ,kohlraus*1 ,h4 ,c4 ,jones1 & ,l[ry1 to %[ t ! ions 9 aque\s solutions ( electrolytes are !mselves hydrat$4 ,limitations ( space preclude fur!r attempts to deal ) ! developm5t ( physical *emi/ry dur+ ! la/ half-c5tury1 & _m important matt]s mu/ rema9 practically unnotic$4 ,! subject ( !rmo-*emi/ry is ma9ly ! creation ( ! la/ half-c5tury1 elaborat$ by ! lab\rs ( ,hess1 ,&rews1 ,?oms51 ,favre & ,silb]mann1 & ,b]!lot4 ,! "w ( ,w5zel & ,b]?ollet on ! influ5ce ( molecul> conc5tration on *emical *ange has be5 greatly ext5d$ by ,b]!lot1 ,guldb]g & ,waage1 ,julius ,?oms51 ,van 't ,h(f1 ,h>c\rt & ,esson1 & ,le ,*ateli]2 & ! !ory ( mass action & ! nature ( rev]sible processes are n[ capable ( def9ite expression1 & c be prov$ indep5d5tly by !rmo-dynamical & k9etic reason+4 ,! ph5om5a ( catalysis & ! action ( enzymes & ( f]m5tation 9 g5]al h receiv$ att5tion f _m inve/igators4 ,! ph5om5a ( gase\s transpiration h be5 /udi$ by ,graham1 ,maxwell1 & ,o4 ,e4 ,mey]4 ,!rmal dissociation has be5 exp]im5tally obs]v$ by ,deville1 ,troo/1 & o!rs1 & ma!matically inve/igat$ by ,will>d ,gibbs & ,van d] ,waals2 & its analogy to electrolytic dissociation has be5 e/abli%$4 ,! nature ( gase\s explosions has be5 inve/igat$ by ,b]!lot1 ,le ,*ateli]1 ,abel1 & ,dixon4 ,important "w has be5 done by ,glad/one1 ,lor5tz1 ,l&olt1 ,nas9i1 ,brhl1 & o!rs1 on ! connection betwe5 ! nature & con/itution ( sub/ances & _! optical *>act]s4 ,simil> "w has be5 done by ,sir ,william ,p]k9 z reg>ds _! magnetic rotation1 & by ,?orpe & ,rodg] ) ref]5ce to _! viscosity4 ,! !ory ( phases1 orig9at+ ) ,gibbs & develop$ by ,van d] ,waals & ,roozeboom1 has be5 greatly ext5d$4 ,sir ,j4 ,j4 ,?omson & ,sir ,j4 ,l>mor h elaborat$ an electrical !ory ( ! atom4 ,b>l[ & ,pope h trac$ ! relation betwe5 val5cy & volume1 & ! accurate measurem5ts ( ,gro? & ( ,tutton h ext5d$ our k ( ! cry/allographic relations ( correlat$ sub/ances4 ,la/ly1 ! :ole subject ( photo-*emi/ry1 al?\gh orig9at+ ) ! obs]vations ( ,+5h\sz1 ,s*eele1 & ,s5ebi]1 may be said to h be5 /udi$ only )9 our own "t1 notably by ,buns5 & ,roscoe1 ,pr+%eim1 ,pfeff]1 ,vogel1 & ,abney4 ,,bibliography ,,relat+ ,,to ,,! ,,p]iod ,,cov]$ ,,by ,,vol ,,ii4 ,alembic ,club1 ,publications ( !4 ,w4 ,clay1 ,ed9burgh4 ,arrh5ius1 ,svante4 ,!ories ( ,*emi/ry4 ,translat$ by ,t4 ,slat] ,price4 ,longmans1 #aijg4 ,beil/e9's ,h&bu* d] ,organis*5 ,*emie4 ,n9e vols4 ,leopold ,voss1 ,hamburg1 #aija-aijf4 ,bis*(f's ,mat]ial5 d] ,/]eo*emie4 ,vieweg & ,son1 ,brunswick1 #aijd4 ,bis*(f & ,wald5's ,h&bu* d] ,/]eo*emie4 ,h4 ,beckhold1 ,frank=t-on-!-,ma91 #ahid4 ,ca91 ,j4 ,c41 & ,?orpe1 ,j4 ,f4 ,syn!tic ,dye/uffs & ,int]m$iate ,products4 ,griff9 & ,co41 #aije4 ,*emical ,society's ,annual ,reports4 ,gurney & ,jackson4 ,*emical ,society4 ,memorial ,lectures1 #ahic-aijj4 ,gurney & ,jackson1 #aija4 ,coh51 ,julius ,b4 ,organic ,*emi/ry4 ,edw>d ,arnold1 #aijg4 ,curie1 ,m>ie4 ,radio-,active ,sub/ances4 8,*emical ,news10 ,london1 #aijc4 ,f9dlay1 ,a4 ,! ,phase ,rule4 ,longmans1 #aijd4 ,fis*]1 ,emil4 ,die ,am9osur51 ,polypeptide und ,prote9e4 ,julius ,spr+]1 ,b]l91 #aijf4 ,fis*]1 ,emil4 ,unt]su*ung5 9 d] ,pur+ruppe4 ,julius ,spr+]1 ,b]l91 #aijg4 ,fis*]1 ,emil4 ,unt]su*ung5 b] ,kohl5hydrate und ,f]m5te4 ,julius ,spr+]1 ,b]l91 #aiji4 ,freund1 ,ida4 ,/udy ( ,*emical ,composition4 ,cambridge ,univ]sity ,press1 #aijd4 ,g>rett1 ,a4 ,e4 ,! ,p]iodic ,law4 ,kegan ,paul1 #aiji4 ,lad5burg1 ,alb]t4 ,developm5t ( ,*emi/ry s9ce ! ,"t ( ,lavoisi]4 ,translat$ by ,leon>d ,dobb94 ,alembic ,club1 ,ed9burgh1 #aijj4 ,l&olt1 ,h4 ,optical ,activity & ,*emical ,composition4 ,translat$ by ,j4 ,mc,crae4 ,:ittak]1 #aijj4 ,laur5t1 ,a4 ,*emical ,me?od4 ,translat$ by ,w4 ,odl+4 ,cav5di% ,society's ,publications1 ,london1 #ahee4 ,mann1 ,gu/av4 ,*emi/ry ( ! ,proteids4 ,macmillan1 #aijf4 ,maxwell1 ,cl]k4 ,!ory ( ,heat4 ,) corrections & additions by ,"l ,rayleigh4 ,longmans4 ,meldola1 ,raphael4 ,*emical ,syn!sis ( ,vital ,products4 ,edw>d ,arnold1 #aijd4 ,m5deleff1 ,d4 ,pr9ciples ( ,*emi/ry4 ,translat$ by ,kam5sky & ,gre5away4 ,longmans4 ,mey]1 ,lo?>4 ,outl9es ( ,!oretical ,*emi/ry4 ,translat$ by ,b$son & ,williams4 ,longmans1 #ahib4 ,mey]1 ,lo?>4 ,mod]n ,!ories ( ,*emi/ry4 ,translat$ by ,b$son & ,williams4 ,longmans1 #ahhh4 ,mey] & ,jacobson's ,lehrbu* d] ,organis*5 ,*emie4 ,veit & ,co41 ,leipzig4 ,mey]1 ,o4 ,e4 ,! ,k9etic ,!ory ( ,gases4 ,translat$ by ,r4 ,e4 ,baynes4 ,longmans1 #ahii4 ,muir1 ,m4 ,m4 ,pattison4 ,hi/ory ( ,*emical ,!ories & ,laws4 ,john ,wiley & ,sons1 ,new ,york1 #aijg4 ,n]n/1 ,walt]4 ,!oretical ,*emi/ry4 ,translat$ by ,c4 ,s4 ,palm]4 ,macmillan1 #ahie4 ,o/wald's ,klassik] d] ,exakt5 ,wiss5s*aft54 ,pictet1 ,am4 ,vegetable ,alkaloids4 ,translat$ by ,h4 ,c4 ,biddle4 ,john ,wiley & ,sons1 ,new ,york1 #aijd4 ,ri*t]'s ,lexikon d] ,kohl5/(f ,v]b9dung54 ,leopold ,voss1 ,hamburg & ,leipzig4 ,roscoe & ,s*orlemm]1 ,treatise on ,*emi/ry4 ,macmillan4 ,ru!r=d1 ,e4 ,radio-,activity4 ,cambridge ,univ]sity ,press1 #aijd4 ,s*orlemm]1 ,c>l4 ,rise & ,developm5t ( ,organic ,*emi/ry4 ,edit$ by ,ar?ur ,smi!lls4 ,macmillan4 ,s*ryv]1 ,s4 ,b4 ,*emi/ry ( ! ,album5s4 ,murray1 #aijf4 ,soddy1 ,f4 ,radio-,activity4 ,! ,electrician ,pr9t+ & ,publi%+ ,co41 ,london1 #aijd4 ,/as4 ,re*]*es sur les ,rapports rciproques des ,poids ,atomique1 #ahfj-ahfe4 ,/ew>t1 ,a4 ,w4 ,rec5t ,advances 9 ,organic ,*emi/ry4 ,longmans1 #aijh4 ,/ew>t1 ,a4 ,w4 ,/]eo ,*emi/ry4 ,longmans1 #aijg4 ,?orpe1 ,t4 ,e4 ,diction>y ( ,appli$ ,*emi/ry4 ,?ree vols4 ,longmans4 ,?orpe1 ,t4 ,e4 ,essays 9 ,hi/orical ,*emi/ry4 ,macmillan1 #aijb4 ,trav]s1 ,morris ,w4 ,/udy ( ,gases4 ,macmillan1 #aija4 ,van 't ,h(f1 ,j4 ,h4 ,arrangem5t ( ,atoms 9 ,space4 ,translat$ by ,a4 ,eilo>t4 ,longmans1 #ahih4 ,walk]1 ,j4 ,introduction to ,physical ,*emi/ry4 ,macmillan4 ,wurtz1 ,ad4 ,! ,atomic ,!ory4 ,translat$ by ,e4 ,clem9%aw4 ,kegan ,paul4 ,,index ,abel1 #ahd ,abney1 #ahe ,absolute z]o1 #ig ,acetanilide1 #aei ,aceto-acetic e/]1 #adh ,act9ium1 #ei ,adr5al9e1 #afj ,agur91 #aeh ,aliz>91 #afb ,alkaloids1 #acb ,allyl alcohol1 #d ,alyh9e1 #afj ,ammonium *loride1 dissociation (1 #ff ,ampre1 #fb ,&]son1 #acc ,&rews1 #gj1 #ie1 #ahc ,anil9e blue1 #d ,anil9e purple1 #d ,antimony1 orig9 ( "n1 #bh ,antipyr91 #aei ,argon1 #dc1 #de1 #df ,argyrodite1 #cg ,arm/rong1 ,e4 ,f41 #aea ,arm/rong1 ,h4 ,e41 #ahc ,aromatic comp\nds1 #aba1 #abc ,arrh5ius1 #agi1 #ahj ,ars9e-dime?yl1 #bj ,artiads1 #aaf ,asymmetry1 #ada ,atmolysis1 #hd ,atomic value1 #aad ,atomic weight1 det]m9ation (1 #ge ,atomicity1 #aad ,atrop9e1 #ace1 #afb its syn!sis #ace ,au/ral5e1 #acj ,autoracemisation1 #add ,avogadro1 #fb 8 hypo!sis1 #fc ,baey]1 #abe1 #abi1 #afa1 #afc ,bal>d1 #aci ,baly1 #abi1 #aea ,bamb]g]1 #adg ,b>bi]1 #aed ,b>l[1 #ahd ,bas>[1 #aeg ,basicity1 #af ,becqu]el1 ,h5ri1 #eb ,behr5d1 #aeg ,b5z5e1 #abc its con/itution1 #abc et seq41 #abh ,b5zidam1 #c ,b]b]9e1 #acf ,b]n\lli1 ,daniel1 #hb ,b]!lot1 ,daniel1 #hb1 #ahc1 #ahd ,b]?ollet1 #ahc ,b]zelius1 #fc ,biot1 #ach ,bitt] almond oil1 #g ,blagd51 ,sir ,*>les1 #gb ,boisbaudran1 ,lecoq de1 #cf1 #ch1 #ci ,boltzmann1 #hc ,bone oil1 #acc ,boron1 specific heat (1 #ga ,boyle's law1 #hd-hg ,braun]1 #cc ,br$t1 #abi1 #acj ,brieg]1 #afa ,brhl1 #adi1 #aea ,buns51 ,rob]t ,w41 #ah1 #cd1 #dc1 #ahe ,buns5 burn]1 #bb ,cacodyl1 #bj ,cadav]9e1 #afa ,csium1 #ba1 #cd ,caffe9e1 #aeg ,cah\rs1 #d1 #acb ,cailletet1 #if ,camph5e1 #aca ,camphor1 #acj1 #aca1 #afb ,cannizz>o1 ,/anislao1 #fd1 #gi ,c>bon1 atomic weight (1 #ge specific heat (1 #ga tetraval5cy (1 #aae ,c>bon c>bonyl1 #aee ,c>bon suboxide1 #aee ,c>nelley1 #ajh ,c>nolite1 #eh ,cav5di%1 #dc1 #de ,cayley1 #abj de ,*anc\rtois1 #ajb ,*loral hydrate1 #aei ,*ol9e1 #afa ,c9*on9e1 #acg ,clausius1 #hc1 #agi ,cleve1 #ch1 #dg ,cleveite1 #dg ,cocane1 #acf1 #afb ,code9e1 #acg ,co9det1 #h ,collie1 #di1 #abh ,cond5sation1 #aeb ,con9e1 #afb ,cons]vation ( mass1 law (1 #gh ,c\m>91 #acb1 #afb ,critical po9t1 #id ,critical pressure1 #ie ,crookes1 ,sir ,william1 #ce1 #dj1 #ge ,curie1 ,m>ie1 #ee ,cyanic acid1 #g ,cyanuric acid1 #g ,debi]ne1 #ei ,decipium1 #dj ,delafonta9e1 #di ,dem>ay1 #cj ,des*1 #aea ,deville1 #ahd ,dew>1 #ga1 #if1 #abg ,dext]1 #aeg ,didymium1 #dj ,digitalis1 #aj ,dis9tegration !ory1 #ed ,dixon1 #ahd ,dobbie1 #aea ,doebn]1 #acd ,dumas1 ,jean ,b4 ,a41 #h1 #i1 #cj1 #ca1 #fc1 #ge1 #ajb1 #acj ,duppa1 #adh ,dysprosium1 #ch ,ede/91 #afi ,electrolysis1 #agi ,elem5ts1 nom5clature (1 #bg ,emanation f ,radium1 #eh ,emanium1 #fj ,enantiomorphism1 #adj ,enzymes1 #add ,e!r1 discov]y ( its con/itution1 #ab1 #ag ,e!r9 !ory1 #aj ,europium1 #ci ,favre1 #ahc ,f5ton's reag5t1 #aed ,f9dlay1 #aea ,fis*]1 ,emil1 #aeh1 #afe1 et seq4 ,fittig1 #aec ,fluor9e1 #cc1 #cd ,=mul1 *emical1 significance (1 #fh ,frankl&1 #aad1 #aaf1 #adh ,fu*s9e1 #d ,fum>ic acid1 #adf ,gadol9ium1 #ci ,gallium1 #cf1 #ajg ,gases1 k9etic !ory (1 #hc law ( diffusion (1 #hd1 #hi liquefaction (1 #id molecul> !ory (1 #gi ,gas-mantles1 #dj ,gay ,lussac1 #fc1 #hj ,geometrical isom]ism1 #adf1 #adg ,g]h>dt1 #gi1 #aac ,g]manium1 #cg1 #ajg ,geu!r1 #adh ,gibbs1 ,will>d1 #ahd ,giesel1 #fj ,glad/one1 #cj1 #ajb1 #ahd ,gmel91 #g1 #fc1 #ajb ,gore1 #cc ,graebe1 #afb ,graham1 ,?omas1 #b1 #ad1 #bc1 #bi1 #hc ,grign>d's reag5t1 #aed ,gro?1 #ahd ,guldb]g1 #ahc ,guye1 #ha ,ha>mann1 #acb ,hmoglob91 #afh ,hantzs*1 #adg ,h>tley1 #aea ,hay1 #aci ,heliotrop91 #acb ,helium1 #dc1 #dg1 #di ,helmholtz1 #aag ,h5ry's law1 #agc ,h]mann1 #bf ,h]s*el1 #adj ,hess1 #aha1 #ahc ,heumann1 #afc ,heymann1 #afc ,hillebr&1 #dg ,hittorf1 #agi ,h(mann1 ,augu/ ,w41 #c1 #fg1 #acc1 #afa ,holmium1 #ch ,hoogew]ff1 #acc ,horbaczewski1 #aeg ,hbn]1 #abg ,hydrog5ium1 #af ,hyoscyam9e1 #ace ,ilm5ium1 #bf ,indigo1 #afb1 #afd ,indigo blue1 #afc ,indium1 #cf ,+5h\sz1 #ahe ,ionisation1 #agh ,ionium1 #eh ,ionone1 #acb ,irone1 #acb ,isoborneol1 #aca ,isocon9e1 #acd ,isoqu9ol9e1 #acc ,isotonic solutions1 #agh ,jones1 ,h4 ,c41 #ahc ,jones1 ,h4 ,o41 #adg ,kahl5b]g1 #ahc ,kamm]l+h ,onnes1 #di1 #ig ,kekul1 ,fri$ri* ,augu/1 #bc1 #aac1 #aad1 #aba1 #abc1 #abe1 #aec ,kiliani1 #afe ,kipp+1 #adg ,kir*h(f1 #ba ,knorr1 #abh1 #aea1 #aei ,ko5igs1 #acc ,kohlraus*1 #ahb1 #ahc ,komppa1 #abi ,kopp1 #agb ,krn]1 #abg ,krss1 #dj ,krypton1 #dc1 #ej ,kry/all91 #c ,kundt1 #df ,la>1 #adi ,lactic acid1 spatial repres5tation (1 #ada ,lad5burg1 #abg1 #acd1 #adg1 #afa ,lamy1 #ce ,l&olt1 #gh1 #ahd ,langlet1 #di ,l>mor1 ,sir ,j41 #ahd ,laud]1 #aea ,laur5t1 #gi ,le ,bel1 #adc1 #adg1 #adh ,l$uc1 #hj1 #ha ,le ,roy]1 #h ,leucol1 #acc ,lieb]mann1 #afb ,liebig1 ,ju/us von1 #e ,l9nemann1 #abg ,liquid diffusion1 #af ,liquids1 molecul> volumes (1 #agb ,loss51 #agb ,l[ry1 #aea1 #ahc ,l[ temp]ature rese>*1 #ig1 #ci ,lutecium1 #hi ,mag5ta1 #d ,magnus1 #gi ,maleic acid1 #adf ,mansfield1 #c ,m>ignac1 #ci1 #ge ,mauve1 #d ,maxwell1 #hc ,m$lock1 #c ,mellitic acid1 #g ,membranes1 semi-p]meable1 #agf ,m5deleff1 #cj1 #ajb1 #aji1 #ahc ,m]cury =ms a monatomic gas1 #ga1 #ib ,metaphosphoric acid1 #ad ,mey] ,lo?>1 #ajc ,mey]1 ,victor1 #fg1 #adg ,mits*]li*1 #fc1 #ach ,moissan1 #cc ,molecule1 integral1 #fb ,molecules1 _! numb]1 #ic _! size1 #ic ,monium1 #dj ,morley1 #hj ,morph9e1 #acg ,mos&]1 #ci ,multirotation1 #ade ,musc>9e1 #afa ,muspratt1 #d ,mut>otation1 #ade ,naph?al5e1 #afc ,n>cene1 #acf ,n>cot9e1 #acf ,nas9i1 #ahd ,natanson1 #aeg ,neodymium1 #ci ,neon1 #dc1 #ej ,neoytt]bium1 #ch ,neur9e1 #afa ,newl&s1 #ajb ,nicot9e1 #ace1 #afb ,nilson1 #cg1 #dj1 #ajg ,nirvan9e1 #afj ,nitrog5 comp\nds1 /]eo-isom]ism (1 #adg ,novocane1 #afj ,odl+1 #cj1 #aad ,oil ( w9t]gre51 #afb ,olszewki1 #if ,opianic acid1 #acf ,organic syn!sis1 #aeb ,or?(orms1 #afj ,osmotic pressure1 #agf ,o/wald1 #ahb ,oxyhmoglob91 #afg ,ozone1 #gj its symbol1 #gj ,papav]9e1 #acf ,p>tial pressure1 law (1 #agc ,pa/eur1 #aci ,pea*ey1 #adh ,pelopium1 #bf ,p5ny1 #ge ,p]iodic law1 #aja ,p]issads1 #aaf ,p]k91 ,sir ,william1 #c1 #abi1 #aca1 #acb1 #afb ,pett5k(]1 #cj ,pfeff]1 #agf1 #ahe ,ph5acet91 #aei ,ph5ylglyc91 #afc ,phosphor\s oxide1 molecul> weight (1 #gc ,phosphorus p5ta*loride1 #ff ,phosphorus p5tafluoride1 #fg ,ph?alic acid1 #afc ,pick]+1 #ahc ,pictet1 #if1 #ace ,p95e1 #acj1 #aca ,p9n]1 #ace ,pip]9e1 #acd1 #afb ,plattn]1 #ce ,playfair1 #bj ,pollucite1 #ce ,pope1 #adg1 #ahd ,posselt1 #ace ,praseodymium1 #ch ,pr+%eim1 #ahe ,protam9es1 #afh ,prote9s1 #afe ,pr\t's law1 an illusion1 #gf ,ptoma9es1 #afa ,pyrid9e1 #acc ,qu99e1 #acg ,qu9ol9e1 #acc ,racemic acid1 #adj ,racemism1 #adc ,radio-?orium1 #fj ,radium1 atomic weight (1 #eh discov]y (1 #ee dis9tegration (1 #eh emanation1 #eh extraction (1 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,tautom]ism1 #adi ,t]eb5!ne1 #acj ,t]p5es1 #abi ,tetan9e1 #afa ,tetronal1 #aei ,?allium1 #ce ,!ba9e1 #acg ,?n>d1 #dc ,!obrom9e1 #aeg ,?ioacetic acid1 #abg ,?oms51 ,julius1 #ea1 #ajh1 #ahc ,?omson1 ,sir ,j4 ,j41 #ahd ,?omson1 ,?omas1 #c ,?orium1 #fj ,?orpe1 #agb1 #ahd ,?ulium1 #ch ,?yreoglobul91 #afi ,tiemann1 #abi1 #acb ,traube1 #agf ,trav]s1 #ej ,trional1 #aei ,triph5ylrosanil9e1 #d ,troo/1 #ahd ,turn]1 ,edw>d1 #b1 #ad1 #ge ,turp5t9e1 oil (1 #abi ,tutton1 #ahd ,type !ory1 #ah ,typhotox9e1 #afa ,unv]dorb51 #c ,uranium1 #ed ,uranium x1 #ed ,urba91 #dj ,urea1 syn!sis (1 #aeg1 #aeh ,uric acid1 #aeh ,val5cy1 #aab ,vanadium1 #cj ,van d] ,waals1 #ie1 #ahd ,van ,dorp1 #acc ,vanill91 #acb1 #afb ,van 't ,h(f1 #aag1 #ada1 #ade1 #adg1 #agc1 #agg ,v]onal1 #aei ,v]qu91 #d ,victorium1 #dj 8,vital =ce0 doctr9e1 #afi ,vogel1 #ahe ,von ,mill]1 #acd ,waage1 #ahc ,walla*1 #abi ,w>burg1 #df ,wat]/on1 #hc ,web]1 #ga ,weisba*1 #cg ,welsba*1 ,au] von1 #ch ,w]n]1 #adg ,williamson1 ,alex&] ,w41 #ad1 #af1 #aac 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( ! v>i\s great bran*es ( k4 ,! ord9>y prim] leaves unexploit$ ! deep human int]e/ :i* belongs to ! sci5ces z contribut+ to progress & civilization1 & call+ into play ! faculties ( _m ( ! f9e/ m9ds4 ,some?+ m attractive is want$4 ,! above ne$ 9 lit]ature has n[ be5 met4 ,ea* volume 9 ,! ,hi/ory ( ,sci5ces is writt5 by an exp]t 9 ! giv5 subject1 & by "o :o has /udi$ ! hi/ory z well z ! conclusions ( 8 own bran* ( sci5ce4 ,! monographs deal briefly ) ! my?s or fallacies :i* prec$$ ! developm5t ( ! giv5 sci5ce1 or include biographical data ( ! great discov]]s4 ,consid]ation is giv5 to ! social & political conditions & to ! attitudes ( rul]s & /atesm5 9 fur!r+ or 9 h9d]+ ! progress ( ! giv5 sci5ce4 ,! volumes record ! important practical application ( ! giv5 sci5ce to ! arts & life ( civiliz$ mank9d1 & also conta9 a c>efully-edit$ bibliography ( ! subject4 ,ea* volume conta9s f twelve to sixte5 c>efully-prep>$ illu/rations1 includ+ portraits ( celebrat$ discov]]s1 _m f orig9als n hi!rto reproduc$1 & explanatory views & diagrams4 ,! s]ies z plann$ %\ld cov] 9 outl9e ! :ole sph]e ( human k4 ,sci5ce is to be view$ z a product ( human endeavor & m5tal discipl9e1 r ?an tak5 9 its purely objective ref]5ce to facts4 ,! ess5tial purpose has be5 to pres5t z f> z practicable ! hi/orical orig9s ( important discov]ies1 also to indicate ! practical utility ( ! sci5ces to human life4 ,g4 ,p4 ,putnam's ,sons ,new ,york ,london ,a ,hi/ory ( ! ,sci5ces ,ea* volume is adequately illu/rat$1 attractively pr9t$1 & sub/antially b\nd4 #afmo4 ,ea*1 net1 #ge c5ts4 ,by mail1 #he c5ts4 #ab illu/rations ,hi/ory ( ,a/ronomy ,by ,george ,=bes1 ,m4,a41 ,f4,r4,s41 ,m4,in/4 ,c4,e4 ,=m]ly ,pr(essor ( ,natural ,philosophy1 ,&]son's ,college1 ,glasg[ ,i ?ank y = ! copy ( ,=bes's ,hi/ory ( ,a/ronomy receiv$4 ,i h run x ov]1 & ?9k x v good inde$4 ,! plan seems excell5t1 & ,i w\ld say ! same ( y\r g5]al plan ( a s]ies ( brief hi/ories ( ! v>i\s bran*es ( sci5ce4 ,! "t appe>s to be ripe = su* a s]ies1 & if all ! contributions are z good z ,pr(4 ,=bes's1 ! book w des]ve a wide circulation1 & w prove v useful to a l>ge class ( read]s4--,extract f a lett] receiv$ f ,g>rett ,p4 ,s]viss1 ,b4 ,s4 ,hi/ory ( ,*emi/ry ,by ,sir ,edw>d ,?orpe1 ,c4,b41 ,,ll4,d41 ,f4,r4,s4 ,au?or ( 8,essays 9 ,hi/orical ,*emi/ry10 8,humphry ,davy3 ,poet & ,philosoph]10 8,joseph ,prie/ley10 etc4 #ab illu/rations4 ,two vols4 ,vol4 ,i--circa #bjjj ,b4,c4 to #ahej ,a4,d4 ,vol4 ,,ii--#ahej ,a4,d4 to date ,! au?or traces ! evolution ( intellectual ?\ght 9 ! progress ( *emical inve/igation1 recogniz+ ! v>i\s po9ts ( view ( ! diff]5t ages1 giv+ due cr$it ev5 to ! anci5ts4 ,x has be5 necess>y to curtail _m p>ts ( ! ,hi/ory1 to lay be=e ! read] 9 unlimit$ space en\gh ab\t ea* age to illu/rate its tone & _s1 ! ideals ( ! work]s1 ! gradual addition ( new po9ts ( view & ( new means ( inve/igation4 ,! ,hi/ory ( ,old ,te/am5t ,criticism ,by ,ar*ibald ,duff ,pr(essor ( ,hebrew & ,old ,te/am5t ,!ology 9 ! ,unit$ ,college1 ,brad=d ,! au?or sets =? ! critical views ( ! ,hebrews conc]n+ _! own lit]ature1 ! e>ly ,*ri/ian treatm5t ( ! ,old ,te/am5t1 criticism by ! ,jewi% rabbis1 & criticism f ,sp9oza to ,a/ruc1 & f ,a/ruc until ! pres5t4 ,9 ,prep>ation ,! ,hi/ory ( ,geography4 ,by ,dr4 ,,john ,,scott ,,keltie1 ,f4,r4,g4,s41 ,f4,s4,a41 ,hon4 ,mem4 ,geographical ,societies ( ,p>is1 ,b]l91 ,rome1 ,brussels1 ,am/]dam1 ,g5eva1 etc4 ,! ,hi/ory ( ,geology4 ,by ,,horace ,b4 ,,woodw>d1 ,f4,r4,s41 ,f4,g4,s41 ,assi/ant ,director ( ,geological ,survey ( ,engl& & ,wales4 ,! ,hi/ory ( ,an?ropology4 ,by ,a4 ,c4 ,,haddon1 ,m4,a41 ,sc4,d41 ,f4,r4,s41 ,lectur] 9 ,e?nology1 ,cambridge & ,london4 ,! ,hi/ory ( ,new ,te/am5t ,criticism4 ,by ,f4 ,c4 ,,conybe>e1 ,m4,a41 late ,fell[ & ,praelector ( ,univ4 ,coll41 ,ox=d2 ,fell[ ( ! ,briti% ,academy2 ,doctor ( ,!ology1 honoris causa1 ( ,giess52 ,(fic] d',academie4 ,fur!r volumes are 9 plan on ! foll[+ subjects3 ,ma!matics & ,me*anics--,molecul> ,physics1 ,heat1 ,light1 & ,electricity--,human ,physiology1 ,embryology1 & ,h]$ity--,ac\/ics1 ,h>monics1 & ! ,physiology ( ,he>+1 toge!r ) ,optics1 ,*romatics1 & ,physiology ( ,see+--,psy*ology1 ,analytic1 ,comp>ative1 & ,exp]im5tal--,sociology & ,economics--,e?ics--,comp>ative ,philology--,criticism1 ,hi/orical ,rese>*1 & ,leg5ds--,comp>ative ,my?ology & ! ,sci5ce ( ,religions--,! ,criticism ( ,ecclesia/ical ,in/itutions--,culture1 ,moral & ,intellectual1 z ,reflect$ 9 ,imag9ative ,lit]ature & 9 ! ,f9e ,arts--,logic--,philosophy--,education4 ,new ,york ,g4 ,p4 ,putnam's ,sons ,london ,transcrib]'s ,notes ,punctuation & spell+ 7 made consi/5t :5 a pr$om9ant pref]5ce 0 f\nd 9 ?is book2 o!rwise !y 7 n *ang$4 ,simple typographical errors 7 correct$2 occasional unbalanc$ quotation m>ks reta9$4 ,ambigu\s hyph5s at ! ends ( l9es 7 reta9$2 occurr5ces ( inconsi/5t hyph5ation h n be5 *ang$4 ,index n *eck$ = prop] alphabetization or correct page ref]5ces4 ,! table on page #aje has be5 split into ?ree p>ts to keep x n>r[4