a history of science-4-第42节

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　Communications；　anthrax　is　not　recurrent；　each　of　our　attenuated　anthrax　microbes　is；　for　the　better…developed　microbe；　a　vaccinethat　is　to　say；　a　virus　producing　a　less…malignant　malady。　What；　therefore；　is　easier　than　to　find　in　these　a　virus　that　will　infect　with　anthrax　sheep；　cows；　and　horses；　without　killing　them；　and　ultimately　capable　of　warding　off　the　mortal　malady？　We　have　practised　this　experiment　with　great　success　upon　sheep；　and　when　the　season　comes　for　the　assembling　of　the　flocks　at　Beauce　we　shall　try　the　experiment　on　a　larger　scale。

〃Already　M。　Toussaint　has　announced　that　sheep　can　be　saved　by　preventive　inoculations；　but　when　this　able　observer　shall　have　published　his　results；　on　the　subject　of　which　we　have　made　such　exhaustive　studies；　as　yet　unpublished；　we　shall　be　able　to　see　the　whole　difference　which　exists　between　the　two　methodsthe　uncertainty　of　the　one　and　the　certainty　of　the　other。　That　which　we　announce　has；　moreover；　the　very　great　advantage　of　resting　upon　the　existence　of　a　poison　vaccine　cultivable　at　will；　and　which　can　be　increased　indefinitely　in　the　space　of　a　few　hours　without　having　recourse　to　infected　blood。〃＇8＇


This　announcement　was　immediately　challenged　in　a　way　that　brought　it　to　the　attention　of　the　entire　world。　The　president　of　an　agricultural　society；　realizing　the　enormous　importance　of　the　subject；　proposed　to　Pasteur　that　his　alleged　discovery　should　be　submitted　to　a　decisive　public　test。　He　proposed　to　furnish　a　drove　of　fifty　sheep　half　of　which　were　to　be　inoculated　with　the　attenuated　virus　of　Pasteur。　　Subsequently　all　the　sheep　were　to　be　inoculated　with　virulent　virus；　all　being　kept　together　in　one　pen　under　precisely　the　same　conditions。　The　〃protected〃　sheep　were　to　remain　healthy；　the　unprotected　ones　to　die　of　anthrax；　so　read　the　terms　of　the　proposition。　Pasteur　accepted　the　challenge；　he　even　permitted　a　change　in　the　programme　by　which　two　goats　were　substituted　for　two　of　the　sheep；　and　ten　cattle　added；　stipulating；　however；　that　since　his　experiments　had　not　yet　been　extended　to　cattle　these　should　not　be　regarded　as　falling　rigidly　within　the　terms　of　the　test。

It　was　a　test　to　try　the　soul　of　any　man；　for　all　the　world　looked　on　askance；　prepared　to　deride　the　maker　of　so　preposterous　a　claim　as　soon　as　his　claim　should　be　proved　baseless。　Not　even　the　fame　of　Pasteur　could　make　the　public　at　large；　lay　or　scientific；　believe　in　the　possibility　of　what　he　proposed　to　accomplish。　　There　was　time　for　all　the　world　to　be　informed　of　the　procedure；　for　the　first　〃preventive〃　inoculationor　vaccination；　as　Pasteur　termed　itwas　made　on　May　5th；　the　second　on　May　17th；　and　another　interval　of　two　weeks　must　elapse　before　the　final　inoculations　with　the　unattenuated　virus。　Twenty…four　sheep；　one　goat；　and　five　cattle　were　submitted　to　the　preliminary　vaccinations。　　Then；　on　May　31　st；　all　sixty　of　the　animals　were　inoculated；　a　protected　and　unprotected　one　alternately；　with　an　extremely　virulent　culture　of　anthrax　microbes　that　had　been　in　Pasteur's　laboratory　since　1877。　This　accomplished；　the　animals　were　left　together　in　one　enclosure　to　await　the　issue。

Two　days　later；　June　2d；　at　the　appointed　hour　of　rendezvous；　a　vast　crowd；　composed　of　veterinary　surgeons；　newspaper　correspondents；　and　farmers　from　far　and　near；　gathered　to　witness　the　closing　scenes　of　this　scientific　tourney。　What　they　saw　was　one　of　the　most　dramatic　scenes　in　the　history　of　peaceful　sciencea　scene　which；　as　Pasteur　declared　afterwards；　〃amazed　the　assembly。〃　　Scattered　about　the　enclosure；　dead；　dying；　or　manifestly　sick　unto　death；　lay　the　unprotected　animals；　one　and　all；　while　each　and　every　〃protected〃　animal　stalked　unconcernedly　about　with　every　appearance　of　perfect　health。　Twenty　of　the　sheep　and　the　one　goat　were　already　dead；　two　other　sheep　expired　under　the　eyes　of　the　spectators；　the　remaining　victims　lingered　but　a　few　hours　longer。　Thus　in　a　manner　theatrical　enough；　not　to　say　tragic；　was　proclaimed　the　unequivocal　victory　of　science。　Naturally　enough；　the　unbelievers　struck　their　colors　and　surrendered　without　terms；　the　principle　of　protective　vaccination；　with　a　virus　experimentally　prepared　in　the　laboratory；　was　established　beyond　the　reach　of　controversy。

That　memorable　scientific　battle　marked　the　beginning　of　a　new　era　in　medicine。　　It　was　a　foregone　conclusion　that　the　principle　thus　established　would　be　still　further　generalized；　that　it　would　be　applied　to　human　maladies；　that　in　all　probability　it　would　grapple　successfully；　sooner　or　later；　with　many　infectious　diseases。　That　expectation　has　advanced　rapidly　towards　realization。　Pasteur　himself　made　the　application　to　the　human　subject　in　the　disease　hydrophobia　in　1885；　since　which　time　that　hitherto　most　fatal　of　maladies　has　largely　lost　its　terrors。　　Thousands　of　persons　bitten　by　mad　dogs　have　been　snatched　from　the　fatal　consequences　of　that　mishap　by　this　method　at　the　Pasteur　Institute　in　Paris；　and　at　the　similar　institutes；　built　on　the　model　of　this　parent　one；　that　have　been　established　all　over　the　world　in　regions　as　widely　separated　as　New　York　and　Nha…Trang。


SERUM…THERAPY

In　the　production　of　the　rabies　vaccine　Pasteur　and　his　associates　developed　a　method　of　attenuation　of　a　virus　quite　different　from　that　which　had　been　employed　in　the　case　of　the　vaccines　of　chicken　cholera　and　of　anthrax。　The　rabies　virus　was　inoculated　into　the　system　of　guinea…pigs　or　rabbits　and；　in　effect；　cultivated　in　the　systems　of　these　animals。　The　spinal　cord　of　these　infected　animals　was　found　to　be　rich　in　the　virus；　which　rapidly　became　attenuated　when　the　cord　was　dried　in　the　air。　　The　preventive　virus；　of　varying　strengths；　was　made　by　maceration　of　these　cords　at　varying　stages　of　desiccation。　This　cultivation　of　a　virus　within　the　animal　organism　suggested；　no　doubt；　by　the　familiar　Jennerian　method　of　securing　small…pox　vaccine；　was　at　the　same　time　a　step　in　the　direction　of　a　new　therapeutic　procedure　which　was　destined　presently　to　become　of　all…absorbing　importancethe　method；　namely；　of　so…called　serum…therapy；　or　the　treatment　of　a　disease　with　the　blood　serum　of　an　animal　that　has　been　subjected　to　protective　inoculation　against　that　disease。

The　possibility　of　such　a　method　was　suggested　by　the　familiar　observation；　made　by　Pasteur　and　numerous　other　workers；　that　animals　of　different　species　differ　widely　in　their　susceptibility　to　various　maladies；　and　that　the　virus　of　a　given　disease　may　become　more　and　more　virulent　when　passed　through　the　systems　of　successive　individuals　of　one　species；　and；　contrariwise；　less　and　less　virulent　when　passed　through　the　systems　of　successive　individuals　of　another　species。　These　facts　suggested　the　theory　that　the　blood　of　resistant　animals　might　contain　something　directly　antagonistic　to　the　virus；　and　the　hope　that　this　something　might　be　transferred　with　curative　effect　to　the　blood　of　an　infected　susceptible　animal。　Numerous　experimenters　all　over　the　world　made　investigations　along　the　line　of　this　alluring　possibility；　the　leaders　perhaps　being　Drs。　　Behring　and　Kitasato；　closely　followed　by　Dr。　Roux　and　his　associates　of　the　Pasteur　Institute　of　Paris。　　Definite　results　were　announced　by　Behring　in　1892　regarding　two　important　diseasestetanus　and　diphtheriabut　the　method　did　not　come　into　general　notice　until　1894；　when　Dr。　Roux　read　an　epoch…making　paper　on　the　subject　at　the　Congress　of　Hygiene　at　Buda…Pesth。

In　this　paper　Dr。　Roux；　after　adverting　to　the　labors　of　Behring；　Ehrlich；　Boer；　Kossel；　and　Wasserman；　described　in　detail　the　methods　that　had　been　developed　at　the　Pasteur　Institute　for　the　development　of　the　curative　serum；　to　which　Behring　had　given　the　since…familiar　name　antitoxine。　The　method　consists；　first；　of　the　cultivation；　for　some　months；　of　the　diphtheria　bacillus　（called　the　Klebs…Loeffler　bacillus；　in　honor　of　its　discoverers）　in　an　artificial　bouillon；　for　the　development　of　a　powerful　toxine　capable　of　giving　the　disease　in　a　virulent　form。

This　toxine；　after　certain　details　of　mechanical　treatment；　is　injected　in　small　but　increasing　doses　into　the　system　of　an　animal；　care　being　taken　to　graduate　the　amount　so　that　the　animal　does　not　succumb　to　the　disease。　After　a　certain　course　of　this　treatment　it　is　found　that　a　portion　of　blood　serum　of　the　animal　so　treated　will　act　in　a　curative　way　if　injected　into　the　blood　of　another　animal；　or　a　human　patient；　suffering　with　diphtheria。　In　other　words；　according　to　theory；　an　antitoxine　has　been　developed　in　the　system　of　the　animal　subjected　to　the　progressive　inoculations　of　the　diphtheria　toxine。　　In　Dr。　Roux's　experience　the　animal　best　suited　for　the　purpose　is　the　horse；　though　almost　any　of　the　domesticated　animals　will　serve　the　purpose。

But　Dr。　Roux's　paper　did　not　stop　with　the　description　of　laboratory　methods。　It　told　also　of　the　practical　application　of　the　serum　to　the　treatment　of　numerous　cases　of　diphtheria　in　the　hospitals　of　Parisapplications　that　had　met　with　a　gratifying　measure　of　success。　　He　made　it　clear　that　a　means　had　been　found　of　coping　successfully　with　what　had　been　one　of　the　most　virulent　and　intractable　of