a history of science-4-第34节

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。　　At　the　age　of　twenty…one　Jenner　had　gone　to　London　to　pursue　his　medical　studies；　and　soon　after　he　proved　himself　so　worthy　a　pupil　that　for　two　years　he　remained　a　member　of　Hunter's　household　as　his　favorite　pupil。　His　taste　for　science　and　natural　history　soon　attracted　the　attention　of　Sir　Joseph　Banks；　who　intrusted　him　with　the　preparation　of　the　zoological　specimens　brought　back　by　Captain　Cook's　expedition　in　1771。　He　performed　this　task　so　well　that　he　was　offered　the　position　of　naturalist　to　the　second　expedition；　but　declined　it；　preferring　to　take　up　the　practice　of　his　profession　in　his　native　town　of　Berkeley。

His　many　accomplishments　and　genial　personality　soon　made　him　a　favorite　both　as　a　physician　and　in　society。　　He　was　a　good　singer；　a　fair　violinist　and　flute…player；　and　a　very　successful　writer　of　prose　and　verse。　But　with　all　his　professional　and　social　duties　he　still　kept　up　his　scientific　investigations；　among　other　things　making　some　careful　observations　on　the　hibernation　of　hedgehogs　at　the　instigation　of　Hunter；　the　results　of　which　were　laid　before　the　Royal　Society。　　He　also　made　quite　extensive　investigations　as　to　the　geological　formations　and　fossils　found　in　his　neighborhood。

Even　during　his　student　days　with　Hunter　he　had　been　much　interested　in　the　belief；　current　in　the　rural　districts　of　Gloucestershire；　of　the　antagonism　between　cow…pox　and　small…pox；　a　person　having　suffered　from　cow…pox　being　immuned　to　small…pox。　At　various　times　Jenner　had　mentioned　the　subject　to　Hunter；　and　he　was　constantly　making　inquiries　of　his　fellow…practitioners　as　to　their　observations　and　opinions　on　the　subject。　Hunter　was　too　fully　engrossed　in　other　pursuits　to　give　the　matter　much　serious　attention；　however；　and　Jenner's　brothers　of　the　profession　gave　scant　credence　to　the　rumors；　although　such　rumors　were　common　enough。

At　this　time　the　practice　of　inoculation　for　preventing　small…pox；　or　rather　averting　the　severer　forms　of　the　disease；　was　widely　practised。　It　was　customary；　when　there　was　a　mild　case　of　the　disease；　to　take　some　of　the　virus　from　the　patient　and　inoculate　persons　who　had　never　had　the　disease；　producing　a　similar　attack　in　them。　Unfortunately　there　were　many　objections　to　this　practice。　The　inoculated　patient　frequently　developed　a　virulent　form　of　the　disease　and　died；　or　if　he　recovered；　even　after　a　mild　attack；　he　was　likely　to　be　〃pitted〃　and　disfigured。　　But；　perhaps　worst　of　all；　a　patient　so　inoculated　became　the　source　of　infection　to　others；　and　it　sometimes　happened　that　disastrous　epidemics　were　thus　brought　about。　　The　case　was　a　most　perplexing　one；　for　the　awful　scourge　of　small…pox　hung　perpetually　over　the　head　of　every　person　who　had　not　already　suffered　and　recovered　from　it。　The　practice　of　inoculation　was　introduced　into　England　by　Lady　Mary　Wortley　Montague　（1690…1762）；　who　had　seen　it　practised　in　the　East；　and　who　announced　her　intention　of　〃introducing　it　into　England　in　spite　of　the　doctors。〃

From　the　fact　that　certain　persons；　usually　milkmaids；　who　had　suffered　from　cow…pox　seemed　to　be　immuned　to　small…pox；　it　would　seem　a　very　simple　process　of　deduction　to　discover　that　cow…pox　inoculation　was　the　solution　of　the　problem　of　preventing　the　disease。　But　there　was　another　form　of　disease　which；　while　closely　resembling　cow…pox　and　quite　generally　confounded　with　it；　did　not　produce　immunity。　The　confusion　of　these　two　forms　of　the　disease　had　constantly　misled　investigations　as　to　the　possibility　of　either　of　them　immunizing　against　smallpox；　and　the　confusion　of　these　two　diseases　for　a　time　led　Jenner　to　question　the　possibility　of　doing　so。　After　careful　investigations；　however；　he　reached　the　conclusion　that　there　was　a　difference　in　the　effects　of　the　two　diseases；　only　one　of　which　produced　immunity　from　small…pox。

〃There　is　a　disease　to　which　the　horse；　from　his　state　of　domestication；　is　frequently　subject；〃　wrote　Jenner；　in　his　famous　paper　on　vaccination。　　〃The　farriers　call　it　the　grease。　It　is　an　inflammation　and　swelling　in　the　heel；　accompanied　at　its　commencement　with　small　cracks　or　fissures；　from　which　issues　a　limpid　fluid　possessing　properties　of　a　very　peculiar　kind。　This　fluid　seems　capable　of　generating　a　disease　in　the　human　body　（after　it　has　undergone　the　modification　I　shall　presently　speak　of）　which　bears　so　strong　a　resemblance　to　small…pox　that　I　think　it　highly　probable　it　may　be　the　source　of　that　disease。

〃In　this　dairy　country　a　great　number　of　cows　are　kept；　and　the　office　of　milking　is　performed　indiscriminately　by　men　and　maid　servants。　　One　of　the　former　having　been　appointed　to　apply　dressings　to　the　heels　of　a　horse　affected　with　the　malady　I　have　mentioned；　and　not　paying　due　attention　to　cleanliness；　incautiously　bears　his　part　in　milking　the　cows　with　some　particles　of　the　infectious　matter　adhering　to　his　fingers。　When　this　is　the　case　it　frequently　happens　that　a　disease　is　communicated　to　the　cows；　and　from　the　cows　to　the　dairy…maids；　which　spreads　through　the　farm　until　most　of　the　cattle　and　domestics　feel　its　unpleasant　consequences。　This　disease　has　obtained　the　name　of　Cow…Pox。　It　appears　on　the　nipples　of　the　cows　in　the　form　of　irregular　pustules。　At　their　first　appearance　they　are　commonly　of　a　palish　blue；　or　rather　of　a　color　somewhat　approaching　to　livid；　and　are　surrounded　by　an　inflammation。　　These　pustules；　unless　a　timely　remedy　be　applied；　frequently　degenerate　into　phagedenic　ulcers；　which　prove　extremely　troublesome。　　The　animals　become　indisposed；　and　the　secretion　of　milk　is　much　lessened。　Inflamed　spots　now　begin　to　appear　on　different　parts　of　the　hands　of　the　domestics　employed　in　milking；　and　sometimes　on　the　wrists；　which　run　on　to　suppuration；　first　assuming　the　appearance　of　the　small　vesications　produced　by　a　burn。　Most　commonly　they　appear　about　the　joints　of　the　fingers　and　at　their　extremities；　but　whatever　parts　are　affected；　if　the　situation　will　admit　the　superficial　suppurations　put　on　a　circular　form　with　their　edges　more　elevated　than　their　centre　and　of　a　color　distinctly　approaching　to　blue。　Absorption　takes　place；　and　tumors　appear　in　each　axilla。　The　system　becomes　affected；　the　pulse　is　quickened；　shiverings；　succeeded　by　heat；　general　lassitude；　and　pains　about　the　loins　and　limbs；　with　vomiting；　come　on。　　The　head　is　painful；　and　the　patient　is　now　and　then　even　affected　with　delirium。　These　symptoms；　varying　in　their　degrees　of　violence；　generally　continue　from　one　day　to　three　or　four；　leaving　ulcerated　sores　about　the　hands　which；　from　the　sensibility　of　the　parts；　are　very　troublesome　and　commonly　heal　slowly；　frequently　becoming　phagedenic；　like　those　from　which　they　sprang。　During　the　progress　of　the　disease　the　lips；　nostrils；　eyelids；　and　other　parts　of　the　body　are　sometimes　affected　with　sores；　but　these　evidently　arise　from　their　being　heedlessly　rubbed　or　scratched　by　the　patient's　infected　fingers。　No　eruptions　on　the　skin　have　followed　the　decline　of　the　feverish　symptoms　in　any　instance　that　has　come　under　my　inspection；　one　only　excepted；　and　in　this　case　a　very　few　appeared　on　the　arms：　they　were　very　minute；　of　a　vivid　red　color；　and　soon　died　away　without　advancing　to　maturation；　so　that　I　cannot　determine　whether　they　had　any　connection　with　the　preceding　symptoms。

〃Thus　the　disease　makes　its　progress　from　the　horse　（as　I　conceive）　to　the　nipple　of　the　cow；　and　from　the　cow　to　the　human　subject。

〃Morbid　matter　of　various　kinds；　when　absorbed　into　the　system；　may　produce　effects　in　some　degree　similar；　but　what　renders　the　cow…pox　virus　so　extremely　singular　is　that　the　person　that　has　been　thus　affected　is　forever　after　secure　from　the　infection　of　small…pox；　neither　exposure　to　the　variolous　effluvia　nor　the　insertion　of　the　matter　into　the　skin　producing　this　distemper。〃＇2＇


In　1796　Jenner　made　his　first　inoculation　with　cowpox　matter；　and　two　months　later　the　same　subject　was　inoculated　with　small…pox　matter。　But；　as　Jenner　had　predicted；　no　attack　of　small…pox　followed。　Although　fully　convinced　by　this　experiment　that　the　case　was　conclusively　proven；　he　continued　his　investigations；　waiting　two　years　before　publishing　his　discovery。　Then；　fortified　by　indisputable　proofs；　he　gave　it　to　the　world。　The　immediate　effects　of　his　announcement　have　probably　never　been　equalled　in　the　history　of　scientific　discovery；　unless；　perhaps；　in　the　single　instance　of　the　discovery　of　anaesthesia。　In　Geneva　and　Holland　clergymen　advocated　the　practice　of　vaccination　from　their　pulpits；　in　some　of　the　Latin　countries　religious　processions　were　formed　for　receiving　vaccination；　Jenner's　birthday　was　celebrated　as　a　feast　in　Germany；　and　the　first　child　vaccinated　in　Russia　was　named　〃Vaccinov〃　and　educated　at　public　expense。　In　six　years　the　discovery　had　penetrated　to　the　most　remote　corners　of　civilization；　it　had　even　reached　some　savage　nations。　And　in　a　few　years　small…pox　had　fallen　from　the　position　of　the　most　dreaded　of　all　diseases　to　that　of　being　practically　the　only　disease　for　which　a　sure　and　easy　preventive　was　known。

Honors　were　showered　upon　Jenner　from　the　Old　and　the　New　World；　and　even　Napoleon；　the　bitter　hater