a history of science-4-第32节

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ose　a　so…called　school　of　neo…Lamarckians；　which　developed　particular　strength　and　prominence　in　America　under　the　leadership　of　Professors　A。　Hyatt　and　E。　D。　Cope。

But　just　as　the　tide　of　opinion　was　turning　strongly　in　this　direction；　an　utterly　unexpected　obstacle　appeared　in　the　form　of　the　theory　of　Professor　August　Weismann；　put　forward　in　1883；　which　antagonized　the　Lamarckian　conception　（though　not　touching　the　Darwinian；　of　which　Weismann　is　a　firm　upholder）　by　denying　that　individual　variations；　however　acquired　by　the　mature　organism；　are　transmissible。　The　flurry　which　this　denial　created　has　not　yet　altogether　subsided；　but　subsequent　observations　seem　to　show　that　it　was　quite　disproportionate　to　the　real　merits　of　the　case。　Notwithstanding　Professor　Weismann's　objections；　the　balance　of　evidence　appears　to　favor　the　view　that　the　Lamarckian　factor　of　acquired　variations　stands　as　the　complement　of　the　Darwinian　factor　of　natural　selection　in　effecting　the　transmutation　of　species。

Even　though　this　partial　explanation　of　what　Professor　Cope　calls　the　〃origin　of　the　fittest〃　be　accepted；　there　still　remains　one　great　life　problem　which　the　doctrine　of　evolution　does　not　touch。　The　origin　of　species；　genera；　orders；　and　classes　of　beings　through　endless　transmutations　is　in　a　sense　explained；　but　what　of　the　first　term　of　this　long　series？　　Whence　came　that　primordial　organism　whose　transmuted　descendants　make　up　the　existing　faunas　and　floras　of　the　globe？

There　was　a　time；　soon　after　the　doctrine　of　evolution　gained　a　hearing；　when　the　answer　to　that　question　seemed　to　some　scientists　of　authority　to　have　been　given　by　experiment。　Recurring　to　a　former　belief；　and　repeating　some　earlier　experiments；　the　director　of　the　Museum　of　Natural　History　at　Rouen；　M。　F。　A。　Pouchet；　reached　the　conclusion　that　organic　beings　are　spontaneously　generated　about　us　constantly；　in　the　familiar　processes　of　putrefaction；　which　were　known　to　be　due　to　the　agency　of　microscopic　bacteria。　But　in　1862　Louis　Pasteur　proved　that　this　seeming　spontaneous　generation　is　in　reality　due　to　the　existence　of　germs　in　the　air。　Notwithstanding　the　conclusiveness　of　these　experiments；　the　claims　of　Pouchet　were　revived　in　England　ten　years　later　by　Professor　Bastian；　but　then　the　experiments　of　John　Tyndall；　fully　corroborating　the　results　of　Pasteur；　gave　a　final　quietus　to　the　claim　of　〃spontaneous　generation〃　as　hitherto　formulated。

There　for　the　moment　the　matter　rests。　　But　the　end　is　not　yet。　Fauna　and　flora　are　here；　and；　thanks　to　Lamarck　and　Wallace　and　Darwin；　their　development；　through　the　operation　of　those　〃secondary　causes〃　which　we　call　laws　of　nature；　has　been　proximally　explained。　The　lowest　forms　of　life　have　been　linked　with　the　highest　in　unbroken　chains　of　descent。　　Meantime；　through　the　efforts　of　chemists　and　biologists；　the　gap　between　the　inorganic　and　the　organic　worlds；　which　once　seemed　almost　infinite；　has　been　constantly　narrowed。　Already　philosophy　can　throw　a　bridge　across　that　gap。　But　inductive　science；　which　builds　its　own　bridges；　has　not　yet　spanned　the　chasm；　small　though　it　appear。　　Until　it　shall　have　done　so；　the　bridge　of　organic　evolution　is　not　quite　complete；　yet　even　as　it　stands　to…day　it　is　perhaps　the　most　stupendous　scientific　structure　of　the　nineteenth　century。



VII。　EIGHTEENTH…CENTURY　MEDICINE

THE　SYSTEM　OF　BOERHAAVE

At　least　two　pupils　of　William　Harvey　distinguished　themselves　in　medicine；　Giorgio　Baglivi　（1669…1707）；　who　has　been　called　the　〃Italian　Sydenham；〃　and　Hermann　Boerhaave　（1668…1738）。　The　work　of　Baglivi　was　hardly　begun　before　his　early　death　removed　one　of　the　most　promising　of　the　early　eighteenth…century　physicians。　　Like　Boerhaave；　he　represents　a　type　of　skilled；　practical　clinitian　rather　than　the　abstract　scientist。　One　of　his　contributions　to　medical　literature　is　the　first　accurate　description　of　typhoid；　or；　as　he　calls　it；　mesenteric　fever。

If　for　nothing　else；　Boerhaave　must　always　be　remembered　as　the　teacher　of　Von　Haller；　but　in　his　own　day　he　was　the　widest　known　and　the　most　popular　teacher　in　the　medical　world。　　He　was　the　idol　of　his　pupils　at　Leyden；　who　flocked　to　his　lectures　in　such　numbers　that　it　became　necessary　to　〃tear　down　the　walls　of　Leyden　to　accommodate　them。〃　His　fame　extended　not　only　all　over　Europe　but　to　Asia；　North　America；　and　even　into　South　America。　　A　letter　sent　him　from　China　was　addressed　to　〃Boerhaave　in　Europe。〃　　His　teachings　represent　the　best　medical　knowledge　of　his　day；　a　high　standard　of　morality；　and　a　keen　appreciation　of　the　value　of　observation；　and　it　was　through　such　teachings　imparted　to　his　pupils　and　advanced　by　them；　rather　than　to　any　new　discoveries；　that　his　name　is　important　in　medical　history。　His　arrangement　and　classification　of　the　different　branches　of　medicine　are　interesting　as　representing　the　attitude　of　the　medical　profession　towards　these　various　branches　at　that　time。


〃In　the　first　place　we　consider　Life；　then　Health；　afterwards　Diseases；　and　lastly　their　several　Remedies。

〃Health　the　first　general　branch　of　Physic　in　our　Institutions　is　termed　Physiology；　or　the　Animal　Oeconomy；　demonstrating　the　several　Parts　of　the　human　Body；　with　their　Mechanism　and　Actions。

〃The　second　branch　of　Physic　is　called　Pathology；　treating　of　Diseases；　their　Differences；　Causes　and　Effects；　or　Symptoms；　by　which　the　human　Body　is　known　to　vary　from　its　healthy　state。

〃The　third　part　of　Physic　is　termed　Semiotica；　which　shows　the　Signs　distinguishing　between　sickness　and　Health；　Diseases　and　their　Causes　in　the　human　Body；　it　also　imports　the　State　and　Degrees　of　Health　and　Diseases；　and　presages　their　future　Events。

〃The　fourth　general　branch　of　Physic　is　termed　Hygiene；　or　Prophylaxis。

〃The　fifth　and　last　part　of　Physic　is　called　Therapeutica；　which　instructs　us　in　the　Nature；　Preparation　and　uses　of　the　Materia　Medica；　and　the　methods　of　applying　the　same；　in　order　to　cure　Diseases　and　restore　lost　Health。〃＇1＇

From　this　we　may　gather　that　his　general　view　of　medicine　was　not　unlike　that　taken　at　the　present　time。

Boerhaave's　doctrines　were　arranged　into　a　〃system〃　by　Friedrich　Hoffmann；　of　Halle　（1660…1742）；　this　system　having　the　merit　of　being　simple　and　more　easily　comprehended　than　many　others。　　In　this　system　forces　were　considered　inherent　in　matter；　being　expressed　as　mechanical　movements；　and　determined　by　mass；　number；　and　weight。　　Similarly；　forces　express　themselves　in　the　body　by　movement；　contraction；　and　relaxation；　etc。；　and　life　itself　is　movement；　〃particularly　movement　of　the　heart。〃　Life　and　death　are；　therefore；　mechanical　phenomena；　health　is　determined　by　regularly　recurring　movements；　and　disease　by　irregularity　of　them。　The　body　is　simply　a　large　hydraulic　machine；　controlled　by　〃the　aether〃　or　〃sensitive　soul；〃　and　the　chief　centre　of　this　soul　lies　in　the　medulla。

In　the　practical　application　of　medicines　to　diseases　Hoffman　used　simple　remedies；　frequently　with　happy　results；　for　whatever　the　medical　man's　theory　may　be　he　seldom　has　the　temerity　to　follow　it　out　logically；　and　use　the　remedies　indicated　by　his　theory　to　the　exclusion　of　long…established；　although　perhaps　purely　empirical；　remedies。　　Consequently；　many　vague　theorists　have　been　excellent　practitioners；　and　Hoffman　was　one　of　these。　Some　of　the　remedies　he　introduced　are　still　in　use；　notably　the　spirits　of　ether；　or　〃Hoffman's　anodyne。〃


ANIMISTS；　VITALISTS；　AND　ORGANICISTS

Besides　Hoffman's　system　of　medicine；　there　were　numerous　others　during　the　eighteenth　century；　most　of　which　are　of　no　importance　whatever；　but　three；　at　least；　that　came　into　existence　and　disappeared　during　the　century　are　worthy　of　fuller　notice。　　One　of　these；　the　Animists；　had　for　its　chief　exponent　Georg　Ernst　Stahl　of　〃phlogiston〃　fame；　another；　the　Vitalists；　was　championed　by　Paul　Joseph　Barthez　（1734…1806）；　and　the　third　was　the　Organicists。　　This　last；　while　agreeing　with　the　other　two　that　vital　activity　cannot　be　explained　by　the　laws　of　physics　and　chemistry；　differed　in　not　believing　that　life　〃was　due　to　some　spiritual　entity；〃　but　rather　to　the　structure　of　the　body　itself。

The　Animists　taught　that　the　soul　performed　functions　of　ordinary　life　in　man；　while　the　life　of　lower　animals　was　controlled　by　ordinary　mechanical　principles。　　Stahl　supported　this　theory　ardently；　sometimes　violently；　at　times　declaring　that　there　were　〃no　longer　any　doctors；　only　mechanics　and　chemists。〃　He　denied　that　chemistry　had　anything　to　do　with　medicine；　and；　in　the　main；　discarded　anatomy　as　useless　to　the　medical　man。　The　soul；　he　thought；　was　the　source　of　all　vital　movement；　and　the　immediate　cause　of　death　was　not　disease　but　the　direct　action　of　the　soul。　　When　through　some　lesion；　or　because　the　machinery　of　the　body　has　become　unworkable；　as　in　old　age；　the　soul　leaves　the　body　and　death　is　produced。　The　soul　ordinarily　selects　the　channels　of　the　circulation；　and　the　contractile　parts；　as　the　route　for　influencing　the　body。　Hence　in　fever　the　pulse　is　quickened；　due　to　the　increased　activity　of　the　soul；　and　convulsions　and　spasmodic　movements　in　disease　are　due；　to　the；　same　cause。　　Stagnation