A Short History of Nearly Everything- 第18部分

the　upshot　is　that　by　the　turn　of　the　twentieth　century；　paleontologists　had　literally　tons　ofold　bones　to　pick　over。　the　problem　was　that　they　still　didn’t　have　any　idea　how　old　any　ofthese　bones　were。　worse；　the　agreed　ages　for　the　earth　couldn’t　fortably　support　thenumbers　of　eons　and　ages　and　epochs　that　the　past　obviously　contained。　if　earth　were　reallyonly　twenty　million　years　old　or　so；　as　the　great　lord　kelvin　insisted；　then　whole　orders　ofancient　creatures　must　have　e　into　being　and　gone　out　again　practically　in　the　samegeological　instant。　it　just　made　no　sense。

other　scientists　besides　kelvin　turned　their　minds　to　the　problem　and　came　up　with　resultsthat　only　deepened　the　uncertainty。　samuel　haughton；　a　respected　geologist　at　trinity　collegein　dublin；　announced　an　estimated　age　for　the　earth　of　2；300　million　years—way　beyondanything　anybody　else　was　suggesting。　when　this　was　drawn　to　his　attention；　he　recalculatedusing　the　same　data　and　put　the　figure　at　153　million　years。　john　joly；　also　of　trinity；　decidedto　give　edmond　halley’s　ocean　salts　idea　a　whirl；　but　his　method　was　based　on　so　manyfaulty　assumptions　that　he　was　hopelessly　adrift。　he　calculated　that　the　earth　was　89　millionyears　old—an　age　that　fit　neatly　enough　with　kelvin’s　assumptions　but　unfortunately　not　withreality。

such　was　the　confusion　that　by　the　close　of　the　nineteenth　century；　depending　on　whichtext　you　consulted；　you　could　learn　that　the　number　of　years　that　stood　between　us　and　thedawn　of　plex　life　in　the　cambrian　period　was　3　million；　18　million；　600　million；　794million；　or　2。4　billion—or　some　other　number　within　that　range。　as　late　as　1910；　one　of　themost　respected　estimates；　by　the　american　george　becker；　put　the　earth’s　age　at　perhaps　aslittle　as　55　million　years。

just　when　matters　seemed　most　intractably　confused；　along　came　another　extraordinaryfigure　with　a　novel　approach。　he　was　a　bluff　and　brilliant　new　zealand　farm　boy　namedernest　rutherford；　and　he　produced　pretty　well　irrefutable　evidence　that　the　earth　was　at　leastmany　hundreds　of　millions　of　years　old；　probably　rather　more。

remarkably；　his　evidence　was　based　on　alchemy—natural；　spontaneous；　scientificallycredible；　and　wholly　non…occult；　but　alchemy　nonetheless。　newton；　it　turned　out；　had　not　beenso　wrong　after　all。　and　exactly　how　that　came　to　be　is　of　course　another　story。

．．



7ELEMENTAL　MATTERSCHEMISTRY

小？说网
as　an　earnest　and　respectable　science　is　often　said　to　date　from　1661；　whenrobert　boyle　of　oxford　published　the　sceptical　chymist　—the　first　work　to　distinguishbetween　chemists　and　alchemists—but　it　was　a　slow　and　often　erratic　transition。　into　theeighteenth　century　scholars　could　feel　oddly　fortable　in　both　camps—like　the　germanjohann　becher；　who　produced　an　unexceptionable　work　on　mineralogy　called　physicasubterranea　；　but　who　also　was　certain　that；　given　the　right　materials；　he　could　make　himselfinvisible。

perhaps　nothing　better　typifies　the　strange　and　often　accidental　nature　of　chemical　sciencein　its　early　days　than　a　discovery　made　by　a　german　named　hennig　brand　in　1675。　brandbecame　convinced　that　gold　could　somehow　be　distilled　from　human　urine。　（the　similarity　ofcolor　seems　to　have　been　a　factor　in　his　conclusion。）　he　assembled　fifty　buckets　of　humanurine；　which　he　kept　for　months　in　his　cellar。　by　various　recondite　processes；　he　converted　theurine　first　into　a　noxious　paste　and　then　into　a　translucent　waxy　substance。　none　of　it　yieldedgold；　of　course；　but　a　strange　and　interesting　thing　did　happen。　after　a　time；　the　substancebegan　to　glow。　moreover；　when　exposed　to　air；　it　often　spontaneously　burst　into　flame。

the　mercial　potential　for　the　stuff—which　soon　became　known　as　phosphorus；　fromgreek　and　latin　roots　meaning　“light　bearing”—was　not　lost　on　eager　businesspeople；　but　thedifficulties　of　manufacture　made　it　too　costly　to　exploit。　an　ounce　of　phosphorus　retailed　forsix　guineas—perhaps　five　hundred　dollars　in　today’s　money—or　more　than　gold。

at　first；　soldiers　were　called　on　to　provide　the　raw　material；　but　such　an　arrangement　washardly　conducive　to　industrial…scale　production。　in　the　1750s　a　swedish　chemist　named　karl（or　carl）　scheele　devised　a　way　to　manufacture　phosphorus　in　bulk　without　the　slop　or　smellof　urine。　it　was　largely　because　of　this　mastery　of　phosphorus　that　sweden　became；　andremains；　a　leading　producer　of　matches。

scheele　was　both　an　extraordinary　and　extraordinarily　luckless　fellow。　a　poor　pharmacistwith　little　in　the　way　of　advanced　apparatus；　he　discovered　eight　elements—chlorine；　fluorine；manganese；　barium；　molybdenum；　tungsten；　nitrogen；　and　oxygen—and　got　credit　for　none　ofthem。　in　every　case；　his　finds　were　either　overlooked　or　made　it　into　publication　aftersomeone　else　had　made　the　same　discovery　independently。　he　also　discovered　many　usefulpounds；　among　them　ammonia；　glycerin；　and　tannic　acid；　and　was　the　first　to　see　themercial　potential　of　chlorine　as　a　bleach—all　breakthroughs　that　made　other　peopleextremely　wealthy。

scheele’s　one　notable　shorting　was　a　curious　insistence　on　tasting　a　little　of　everythinghe　worked　with；　including　such　notoriously　disagreeable　substances　as　mercury；　prussic　acid（another　of　his　discoveries）；　and　hydrocyanic　acid—a　pound　so　famously　poisonous　that150　years　later　erwin　schr？dinger　chose　it　as　his　toxin　of　choice　in　a　famous　thoughtexperiment　（see　page　146）。　scheele’s　rashness　eventually　caught　up　with　him。　in　1786；　agedjust　forty…three；　he　was　found　dead　at　his　workbench　surrounded　by　an　array　of　toxicchemicals；　any　one　of　which　could　have　accounted　for　the　stunned　and　terminal　look　on　hisface。

were　the　world　just　and　swedish…speaking；　scheele　would　have　enjoyed　universal　acclaim。

instead　credit　has　tended　to　lodge　with　more　celebrated　chemists；　mostly　from　the　english…speaking　world。　scheele　discovered　oxygen　in　1772；　but　for　various　heartbreakinglyplicated　reasons　could　not　get　his　paper　published　in　a　timely　manner。　instead　credit　wentto　joseph　priestley；　who　discovered　the　same　element　independently；　but　latterly；　in　thesummer　of　1774。　even　more　remarkable　was　scheele’s　failure　to　receive　credit　for　thediscovery　of　chlorine。　nearly　all　textbooks　still　attribute　chlorine’s　discovery　to　humphrydavy；　who　did　indeed　find　it；　but　thirty…six　years　after　scheele　had。

although　chemistry　had　e　a　long　way　in　the　century　that　separated　newton　and　boylefrom　scheele　and　priestley　and　henry　cavendish；　it　still　had　a　long　way　to　go。　right　up　to　theclosing　years　of　the　eighteenth　century　（and　in　priestley’s　case　a　little　beyond）　scientistseverywhere　searched　for；　and　sometimes　believed　they　had　actually　found；　things　that　justweren’t　there：　vitiated　airs；　dephlogisticated　marine　acids；　phloxes；　calxes；　terraqueousexhalations；　and；　above　all；　phlogiston；　the　substance　that　was　thought　to　be　the　active　agentin　bustion。　somewhere　in　all　this；　it　was　thought；　there　also　resided　a　mysterious　élanvital；　the　force　that　brought　inanimate　objects　to　life。　no　one　knew　where　this　ethereal　essencelay；　but　two　things　seemed　probable：　that　you　could　enliven　it　with　a　jolt　of　electricity　（anotion　mary　shelley　exploited　to　full　effect　in　her　novel　frankenstein　）　and　that　it　existed　insome　substances　but　not　others；　which　is　why　we　ended　up　with　two　branches　of　chemistry：

organic　（for　those　substances　that　were　thought　to　have　it）　and　inorganic　（for　those　that　didnot）。

someone　of　insight　was　needed　to　thrust　chemistry　into　the　modern　age；　and　it　was　thefrench　who　provided　him。　his　name　was　antoine…laurent　lavoisier。　born　in　1743；　lavoisierwas　a　member　of　the　minor　nobility　（his　father　had　purchased　a　title　for　the　family）。　in　1768；he　bought　a　practicing　share　in　a　deeply　despised　institution　called　the　ferme　générale　（orgeneral　farm）；　which　collected　taxes　and　fees　on　behalf　of　the　government。　althoughlavoisier　himself　was　by　all　accounts　mild　and　fair…minded；　the　pany　he　worked　for　wasneither。　for　one　thing；　it　did　not　tax　the　rich　but　only　the　poor；　and　then　often　arbitrarily。　forlavoisier；　the　appeal　of　the　institution　was　that　it　provided　him　with　the　wealth　to　follow　hisprincipal　devotion；　science。　at　his　peak；　his　personal　earnings　reached　150；000　livres　a　year—perhaps　20　million　in　today’s　money。

three　years　after　embarking　on　this　lucrative　career　path；　he　married　the　fourteen…year…olddaughter　of　one　of　his　bosses。　the　marriage　was　a　meeting　of　hearts　and　minds　both。　madamelavoisier　had　an　incisive　intellect　and　soon　was　working　productively　alongside　her　husband。

despite　the　demands　of　his　job　and　busy　social　life；　they　managed　to　put　in　five　hours　ofscience　on　most　days—two　in　the　early　morning　and　three　in　the　evening—as　well　as　thewhole　of　sunday；　which　they　called　their　jour　de　bonheur　（day　of　happiness）。　somehowlavoisier　also　found　the　time　to　be　missioner　of　gunpowder；　supervise　the　building　of　awall　around　paris　to　deter　smugglers；　help　found　the　metric　system；　and　coauthor　thehandbook　méthode　de　nomenclature　chimique　；　which　became　the　bible　for　agreeing　on　thenames　of　the　elements。

as　a　leading　member　of　the　académie　royale　des　sciences；　he　was　also　required　to　take　aninformed　and　active　interest　in　whatever　was　topic