a history of science-4-第12章

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！


me　he　had　had　no　training　of　any　kind　to　prepare　him　for　his　professional　career；　and　knew　little　of　Greek　or　Latinlanguages　entirely　unnecessary　for　him；　as　he　proved　in　all　of　his　life　work。　　Ottley　tells　the　story　that；　when　twitted　with　this　lack　of　knowledge　of　the　〃dead　languages〃　in　after　life；　he　said　of　his　opponent；　〃I　could　teach　him　that　on　the　dead　body　which　he　never　knew　in　any　language；　dead　or　living。〃

By　his　second　year　in　dissection　he　had　become　so　skilful　that　he　was　given　charge　of　some　of　the　classes　in　his　brother's　school；　in　1754　he　became　a　surgeon's　pupil　in　St。　George's　Hospital；　and　two　years　later　house…surgeon。　Having　by　overwork　brought　on　symptoms　that　seemed　to　threaten　consumption；　he　accepted　the　position　of　staff…surgeon　to　an　expedition　to　Belleisle　in　1760；　and　two　years　later　was　serving　with　the　English　army　at　Portugal。　　During　all　this　time　he　was　constantly　engaged　in　scientific　researches；　many　of　which；　such　as　his　observations　of　gun…shot　wounds；　he　put　to　excellent　use　in　later　life。　On　returning　to　England　much　improved　in　health　in　1763；　he　entered　at　once　upon　his　career　as　a　London　surgeon；　and　from　that　time　forward　his　progress　was　a　practically　uninterrupted　series　of　successes　in　his　profession。

Hunter's　work　on　the　study　of　the　lymphatics　was　of　great　service　to　the　medical　profession。　　This　important　net…work　of　minute　vessels　distributed　throughout　the　body　had　recently　been　made　the　object　of　much　study；　and　various　students；　including　Haller；　had　made　extensive　investigations　since　their　discovery　by　Asellius。　　But　Hunter；　in　1758；　was　the　first　to　discover　the　lymphatics　in　the　neck　of　birds；　although　it　was　his　brother　William　who　advanced　the　theory　that　the　function　of　these　vessels　was　that　of　absorbents。　One　of　John　Hunter's　pupils；　William　Hewson　（1739…1774）；　first　gave　an　account；　in　1768；　of　the　lymphatics　in　reptiles　and　fishes；　and　added　to　his　teacher's　investigations　of　the　lymphatics　in　birds。　These　studies　of　the　lymphatics　have　been　regarded；　perhaps　with　justice；　as　Hunter's　most　valuable　contributions　to　practical　medicine。

In　1767　he　met　with　an　accident　by　which　he　suffered　a　rupture　of　the　tendo　Achillisthe　large　tendon　that　forms　the　attachment　of　the　muscles　of　the　calf　to　the　heel。　From　observations　of　this　accident；　and　subsequent　experiments　upon　dogs；　he　laid　the　foundation　for　the　now　simple　and　effective　operation　for　the　cure　of　club　feet　and　other　deformities　involving　the　tendons。　　In　1772　he　moved　into　his　residence　at　Earlscourt；　Brompton；　where　he　gathered　about　him　a　great　menagerie　of　animals；　birds；　reptiles；　insects；　and　fishes；　which　he　used　in　his　physiological　and　surgical　experiments。　Here　he　performed　a　countless　number　of　experimentsmore；　probably；　than　〃any　man　engaged　in　professional　practice　has　ever　conducted。〃　These　experiments　varied　in　nature　from　observations　of　the　habits　of　bees　and　wasps　to　major　surgical　operations　performed　upon　hedgehogs；　dogs；　leopards；　etc。　　It　is　said　that　for　fifteen　years　he　kept　a　flock　of　geese　for　the　sole　purpose　of　studying　the　process　of　development　in　eggs。

Hunter　began　his　first　course　of　lectures　in　1772；　being　forced　to　do　this　because　he　had　been　so　repeatedly　misquoted；　and　because　he　felt　that　he　could　better　gauge　his　own　knowledge　in　this　way。　Lecturing　was　a　sore　trial　to　him；　as　he　was　extremely　diffident；　and　without　writing　out　his　lectures　in　advance　he　was　scarcely　able　to　speak　at　all。　　In　this　he　presented　a　marked　contrast　to　his　brother　William；　who　was　a　fluent　and　brilliant　speaker。　Hunter's　lectures　were　at　best　simple　readings　of　the　facts　as　he　had　written　them；　the　diffident　teacher　seldom　raising　his　eyes　from　his　manuscript　and　rarely　stopping　until　his　complete　lecture　had　been　read　through。　　His　lectures　were；　therefore；　instructive　rather　than　interesting；　as　he　used　infinite　care　in　preparing　them；　but　appearing　before　his　classes　was　so　dreaded　by　him　that　he　is　said　to　have　been　in　the　habit　of　taking　a　half…drachm　of　laudanum　before　each　lecture　to　nerve　him　for　the　ordeal。　One　is　led　to　wonder　by　what　name　he　shall　designate　that　quality　of　mind　that　renders　a　bold　and　fearless　surgeon　like　Hunter；　who　is　undaunted　in　the　face　of　hazardous　and　dangerous　operations；　a　stumbling；　halting；　and　〃frightened〃　speaker　before　a　little　band　of；　at　most；　thirty　young　medical　students。　　And　yet　this　same　thing　is　not　unfrequently　seen　among　the　boldest　surgeons。


Hunter's　Operation　for　the　Cure　of　Aneurisms

It　should　be　an　object…lesson　to　those　who；　ignorantly　or　otherwise；　preach　against　the　painless　vivisection　as　practised　to…day；　that　by　the　sacrifice　of　a　single　deer　in　the　cause　of　science　Hunter　discovered　a　fact　in　physiology　that　has　been　the　means　of　saving　thousands　of　human　lives　and　thousands　of　human　bodies　from　needless　mutilation。　We　refer　to　the　discovery　of　the　〃collateral　circulation〃　of　the　blood；　which　led；　among　other　things；　to　Hunter's　successful　operation　upon　aneurisms。

Simply　stated；　every　organ　or　muscle　of　the　body　is　supplied　by　one　large　artery；　whose　main　trunk　distributes　the　blood　into　its　lesser　branches；　and　thence　through　the　capillaries。　Cutting　off　this　main　artery；　it　would　seem；　should　cut　off　entirely　the　blood…supply　to　the　particular　organ　which　is　supplied　by　this　vessel；　and　until　the　time　of　Hunter's　demonstration　this　belief　was　held　by　most　physiologists。　But　nature　has　made　a　provision　for　this　possible　stoppage　of　blood…supply　from　a　single　source；　and　has　so　arranged　that　some　of　the　small　arterial　branches　coming　from　the　main　supply…trunk　are　connected　with　other　arterial　branches　coming　from　some　other　supply…trunk。　Under　normal　conditions　the　main　arterial　trunks　supply　their　respective　organs；　the　little　connecting　arterioles　playing　an　insignificant　part。　But　let　the　main　supply…trunk　be　cut　off　or　stopped　for　whatever　reason；　and　a　remarkable　thing　takes　place。　The　little　connecting　branches　begin　at　once　to　enlarge　and　draw　blood　from　the　neighboring　uninjured　supply…trunk；　This　enlargement　continues　until　at　last　a　new　route　for　the　circulation　has　been　established；　the　organ　no　longer　depending　on　the　now　defunct　original　arterial　trunk；　but　getting　on　as　well　as　before　by　this　〃collateral〃　circulation　that　has　been　established。

The　thorough　understanding　of　this　collateral　circulation　is　one　of　the　most　important　steps　in　surgery；　for　until　it　was　discovered　amputations　were　thought　necessary　in　such　cases　as　those　involving　the　artery　supplying　a　leg　or　arm；　since　it　was　supposed　that；　the　artery　being　stopped；　death　of　the　limb　and　the　subsequent　necessity　for　amputation　were　sure　to　follow。　Hunter　solved　this　problem　by　a　single　operation　upon　a　deer；　and　his　practicality　as　a　surgeon　led　him　soon　after　to　apply　this　knowledge　to　a　certain　class　of　surgical　cases　in　a　most　revolutionary　and　satisfactory　manner。

What　led　to　Hunter's　far…reaching　discovery　was　his　investigation　as　to　the　cause　of　the　growth　of　the　antlers　of　the　deer。　Wishing　to　ascertain　just　what　part　the　blood…supply　on　the　opposite　sides　of　the　neck　played　in　the　process　of　development；　or；　perhaps　more　correctly；　to　see　what　effect　cutting　off　the　main　blood…supply　would　have；　Hunter　had　one　of　the　deer　of　Richmond　Park　caught　and　tied；　while　he　placed　a　ligature　around　one　of　the　carotid　arteriesone　of　the　two　principal　arteries　that　supply　the　head　with　blood。　He　observed　that　shortly　after　this　the　antler　（which　was　only　half　grown　and　consequently　very　vascular）　on　the　side　of　the　obliterated　artery　became　cold　to　the　touchfrom　the　lack　of　warmth…giving　blood。　There　was　nothing　unexpected　in　this；　and　Hunter　thought　nothing　of　it　until　a　few　days　later；　when　he　found；　to　his　surprise；　that　the　antler　had　become　as　warm　as　its　fellow；　and　was　apparently　increasing　in　size。　Puzzled　as　to　how　this　could　be；　and　suspecting　that　in　some　way　his　ligature　around　the　artery　had　not　been　effective；　he　ordered　the　deer　killed；　and　on　examination　was　astonished　to　find　that　while　his　ligature　had　completely　shut　off　the　blood…supply　from　the　source　of　that　carotid　artery；　the　smaller　arteries　had　become　enlarged　so　as　to　supply　the　antler　with　blood　as　well　as　ever；　only　by　a　different　route。

Hunter　soon　had　a　chance　to　make　a　practical　application　of　the　knowledge　thus　acquired。　　This　was　a　case　of　popliteal　aneurism；　operations　for　which　had　heretofore　proved　pretty　uniformly　fatal。　An　aneurism；　as　is　generally　understood；　is　an　enlargement　of　a　certain　part　of　an　artery；　this　enlargement　sometimes　becoming　of　enormous　size；　full　of　palpitating　blood；　and　likely　to　rupture　with　fatal　results　at　any　time。　　If　by　any　means　the　blood　can　be　allowed　to　remain　quiet　for　even　a　few　hours　in　this　aneurism　it　will　form　a　clot；　contract；　and　finally　be　absorbed　and　disappear　without　any　evil　results。　The　problem　of　keeping　the　blood　quiet；　with　the　heart　continually　driving　it　through　the　vessel；　is　not　a　simple　one；　and　in　Hunter's　time　was　considered　so　insurmountable　that　some　surgeons　advocated　amputation　of　any　member　having　an　aneurism；　while　others　cut　down　upon　the　tumor　itself　and　attempted　to　tie　off　the　artery　above　and　below。　The　first　of　these　operations　maimed　the　patient　for　life；　while　the　second　was　likely　to　prove　fatal。

In　pondering　over　what　he　had　learned　about　collateral　circulation　and　the　time　required　for　it　to　become　fully　established；　Hunter　conceived　the　idea　that　if　the　blood…supply　was　cut　off　from　above　the　aneurism；　thus　temporarily　preventing　the　ceaseless　pulsations　from　the　heart；　this　blood　would　coagulate　and　form　a　clot　before　the　collateral　circulation　could　become　established　or　could　affect　it。　　The　patient　upon　whom　he　performed　his　now　celebrated　operation　was　afflicted　with　a　popliteal　aneurismthat　is；　the　aneurism　was　located　on　the　large　popliteal　artery　just　behind　the　knee…joint。　Hunter；　therefore；　tied　off　the　femoral；　or　main　supplying　artery　in　the　thigh；　a　little　distance　above　the　aneurism。　The　operation　was　entirely　successful；　and　in　six　weeks'　time　the　patient　was　able　to　leave　the　hospital；　and　with　two　sound　limbs。　Naturally　the　simplicity　and　success　of　this　operation　aroused　the　attention　of　Europe；　and；　alone；　would　have　made　the　name　of　Hunter　immortal　in　the　annals　of　surgery。　　The　operation　has　ever　since　been　called　the　〃Hunterian〃　operation　for　aneurism；　but　there　is　reason　to　believe　that　Dominique　Anel　（born　about　1679）　performed　a　somewhat　similar　operation　several　years　earlier。　It　is　probable；　however；　that　Hunter　had　never　heard　of　this　work　of　Anel；　and　that　his　operation　was　the　outcome　of　his　own　independent　reasoning　from　the　facts　he　had　learned　about　collateral　circulation。　Furthermore；　Hunter's　mode　of　operation　was　a　much　better　one　than　Anel's；　and；　while　Anel's　must　claim　priority；　the　credit　of　making　it　widely　known　will　always　be　Hunter's。

The　great　services　of　Hunter　were　recognized　both　at　home　and　abroad；　and　honors　and　positions　of　honor　and　responsibility　were　given　him。　In　1776　he　was　appointed　surgeon…extraordinary　to　the　king；　in　1783　he　was　elected　a　member　of　the　Royal　Society　of　Medicine　and　of　the　Royal　Academy　of　Surgery　a