a history of science-2-第6部分

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　from　persecution；　he　finally　perished　by　shipwreck。　Arnald　was　the　first　great　representative　of　the　school　of　Montpellier。　He　devoted　much　time　to　the　study　of　chemicals；　and　was　active　in　attempting　to　re…establish　the　teachings　of　Hippocrates　and　Galen。　He　was　one　of　the　first　of　a　long　line　of　alchemists　who；　for　several　succeeding　centuries；　expended　so　much　time　and　energy　in　attempting　to　find　the　〃elixir　of　life。〃　The　Arab　discovery　of　alcohol　first　deluded　him　into　the　belief　that　the　〃elixir〃　had　at　last　been　found；　but　later　he　discarded　it　and　made　extensive　experiments　with　brandy；　employing　it　in　the　treatment　of　certain　diseasesthe　first　record　of　the　administration　of　this　liquor　as　a　medicine。　Arnald　also　revived　the　search　for　some　anaesthetic　that　would　produce　insensibility　to　pain　in　surgical　operations。　This　idea　was　not　original　with　him；　for　since　very　early　times　physicians　had　attempted　to　discover　such　an　anaesthetic；　and　even　so　early　a　writer　as　Herodotus　tells　how　the　Scythians；　by　inhalation　of　the　vapors　of　some　kind　of　hemp；　produced　complete　insensibility。　It　may　have　been　these　writings　that　stimulated　Arnald　to　search　for　such　an　anaesthetic。　In　a　book　usually　credited　to　him；　medicines　are　named　and　methods　of　administration　described　which　will　make　the　patient　insensible　to　pain；　so　that　〃he　may　be　cut　and　feel　nothing；　as　though　he　were　dead。〃　For　this　purpose　a　mixture　of　opium；　mandragora；　and　henbane　is　to　be　used。　This　mixture　was　held　at　the　patient's　nostrils　much　as　ether　and　chloroform　are　administered　by　the　modern　surgeon。　The　method　was　modified　by　Hugo　of　Lucca　（died　in　1252　or　1268）；　who　added　certain　other　narcotics；　such　as　hemlock；　to　the　mixture；　and　boiled　a　new　sponge　in　this　decoction。　After　boiling　for　a　certain　time；　this　sponge　was　dried；　and　when　wanted　for　use　was　dipped　in　hot　water　and　applied　to　the　nostrils。　Just　how　frequently　patients　recovered　from　the　administration　of　such　a　combination　of　powerful　poisons　does　not　appear；　but　the　percentage　of　deaths　must　have　been　very　high；　as　the　practice　was　generally　condemned。　Insensibility　could　have　been　produced　only　by　swallowing　large　quantities　of　the　liquid；　which　dripped　into　the　nose　and　mouth　when　the　sponge　was　applied；　and　a　lethal　quantity　might　thus　be　swallowed。　The　method　was　revived；　with　various　modifications；　from　time　to　time；　but　as　often　fell　into　disuse。　As　late　as　1782　it　was　sometimes　attempted；　and　in　that　year　the　King　of　Poland　is　said　to　have　been　completely　anaesthetized　and　to　have　recovered；　after　a　painless　amputation　had　been　performed　by　the　surgeons。　Peter　of　Abano　was　one　of　the　first　great　men　produced　by　the　University　of　Padua。　His　fate　would　have　been　even　more　tragic　than　that　of　the　shipwrecked　Arnald　had　he　not　cheated　the　purifying　fagots　of　the　church　by　dying　opportunely　on　the　eve　of　his　execution　for　heresy。　But　if　his　spirit　had　cheated　the　fanatics；　his　body　could　not；　and　his　bones　were　burned　for　his　heresy。　He　had　dared　to　deny　the　existence　of　a　devil；　and　had　suggested　that　the　case　of　a　patient　who　lay　in　a　trance　for　three　days　might　help　to　explain　some　miracles；　like　the　raising　of　Lazarus。　His　great　work　was　Conciliator　Differentiarum；　an　attempt　to　reconcile　physicians　and　philosophers。　But　his　researches　were　not　confined　to　medicine；　for　he　seems　to　have　had　an　inkling　of　the　hitherto　unknown　fact　that　air　possesses　weight；　and　his　calculation　of　the　length　of　the　year　at　three　hundred　and　sixty…five　days；　six　hours；　and　four　minutes；　is　exceptionally　accurate　for　the　age　in　which　he　lived。　He　was　probably　the　first　of　the　Western　writers　to　teach　that　the　brain　is　the　source　of　the　nerves；　and　the　heart　the　source　of　the　vessels。　From　this　it　is　seen　that　he　was　groping　in　the　direction　of　an　explanation　of　the　circulation　of　the　blood；　as　demonstrated　by　Harvey　three　centuries　later。　The　work　of　Arnald　and　Peter　of　Abano　in　〃reviving〃　medicine　was　continued　actively　by　Mondino　（1276…1326）　of　Bologna；　the　〃restorer　of　anatomy；〃　and　by　Guy　of　Chauliac：　（born　about　1300）；　the　〃restorer　of　surgery。〃　All　through　the　early　Middle　Ages　dissections　of　human　bodies　had　been　forbidden；　and　even　dissection　of　the　lower　animals　gradually　fell　into　disrepute　because　physicians　detected　in　such　practices　were　sometimes　accused　of　sorcery。　Before　the　close　of　the　thirteenth　century；　however；　a　reaction　had　begun；　physicians　were　protected；　and　dissections　were　occasionally　sanctioned　by　the　ruling　monarch。　Thus　Emperor　Frederick　H。　（1194…1250　A。D。）whose　services　to　science　we　have　already　had　occasion　to　mentionordered　that　at　least　one　human　body　should　be　dissected　by　physicians　in　his　kingdom　every　five　years。　By　the　time　of　Mondino　dissections　were　becoming　more　frequent；　and　he　himself　is　known　to　have　dissected　and　demonstrated　several　bodies。　His　writings　on　anatomy　have　been　called　merely　plagiarisms　of　Galen；　but　in　all　probability　be　made　many　discoveries　independently；　and　on　the　whole；　his　work　may　be　taken　as　more　advanced　than　Galen's。　His　description　of　the　heart　is　particularly　accurate；　and　he　seems　to　have　come　nearer　to　determining　the　course　of　the　blood　in　its　circulation　than　any　of　his　predecessors。　In　this　quest　he　was　greatly　handicapped　by　the　prevailing　belief　in　the　idea　that　blood…vessels　must　contain　air　as　well　as　blood；　and　this　led　him　to　assume　that　one　of　the　cavities　of　the　heart　contained　〃spirits；〃　or　air。　It　is　probable；　however；　that　his　accurate　observations；　so　far　as　they　went；　were　helpful　stepping…stones　to　Harvey　in　his　discovery　of　the　circulation。　Guy　of　Chauliac；　whose　innovations　in　surgery　reestablished　that　science　on　a　firm　basis；　was　not　only　one　of　the　most　cultured；　but　also　the　most　practical　surgeon　of　his　time。　He　had　great　reverence　for　the　works　of　Galen；　Albucasis；　and　others　of　his　noted　predecessors；　but　this　reverence　did　not　blind　him　to　their　mistakes　nor　prevent　him　from　using　rational　methods　of　treatment　far　in　advance　of　theirs。　His　practicality　is　shown　in　some　of　his　simple　but　useful　inventions　for　the　sick…room；　such　as　the　device　of　a　rope；　suspended　from　the　ceiling　over　the　bed；　by　which　a　patient　may　move　himself　about　more　easily；　and　in　some　of　his　improvements　in　surgical　dressings；　such　as　stiffening　bandages　by　dipping　them　in　the　white　of　an　egg　so　that　they　are　held　firmly。　He　treated　broken　limbs　in　the　suspended　cradle　still　in　use；　and　introduced　the　method　of　making　〃traction〃　on　a　broken　limb　by　means　of　a　weight　and　pulley；　to　prevent　deformity　through　shortening　of　the　member。　He　was　one　of　the　first　physicians　to　recognize　the　utility　of　spectacles；　and　recommended　them　in　cases　not　amenable　to　treatment　with　lotions　and　eye…waters。　In　some　of　his　surgical　operations；　such　as　trephining　for　fracture　of　the　skull；　his　technique　has　been　little　improved　upon　even　in　modern　times。　In　one　of　these　operations　he　successfully　removed　a　portion　of　a　man's　brain。

Surgery　was　undoubtedly　stimulated　greatly　at　this　period　by　the　constant　wars。　Lay　physicians；　as　a　class；　had　been　looked　down　upon　during　the　Dark　Ages；　but　with　the　beginning　of　the　return　to　rationalism；　the　services　of　surgeons　on　the　battle…field；　to　remove　missiles　from　wounds；　and　to　care　for　wounds　and　apply　dressings；　came　to　be　more　fully　appreciated。　In　return　for　his　labors　the　surgeon　was　thus　afforded　better　opportunities　for　observing　wounds　and　diseases；　which　led　naturally　to　a　gradual　improvement　in　surgical　methods。

FIFTEENTH…CENTURY　MEDICINE　The　thirteenth　and　fourteenth　centuries　had　seen　some　slight　advancement　in　the　science　of　medicine；　at　least；　certain　surgeons　and　physicians；　if　not　the　generality；　had　made　advances；　but　it　was　not　until　the　fifteenth　century　that　the　general　revival　of　medical　learning　became　assured。　In　this　movement；　naturally；　the　printing…press　played　an　all…important　part。　Medical　books；　hitherto　practically　inaccessible　to　the　great　mass　of　physicians；　now　became　common；　and　this　output　of　reprints　of　Greek　and　Arabic　treatises　revealed　the　fact　that　many　of　the　supposed　true　copies　were　spurious。　These　discoveries　very　naturally　aroused　all　manner　of　doubt　and　criticism；　which　in　turn　helped　in　the　development　of　independent　thought。　A　certain　manuscript　of　the　great　Cornelius　Celsus；　the　De　Medicine；　which　had　been　lost　for　many　centuries；　was　found　in　the　church　of　St。　Ambrose；　at　Milan；　in　1443；　and　was　at　once　put　into　print。　The　effect　of　the　publication　of　this　book；　which　had　lain　in　hiding　for　so　many　centuries；　was　a　revelation；　showing　the　medical　profession　how　far　most　of　their　supposed　true　copies　of　Celsus　had　drifted　away　from　the　original。　The　indisputable　authenticity　of　this　manuscript；　discovered　and　vouched　for　by　the　man　who　shortly　after　became　Pope　Nicholas　V。；　made　its　publication　the　more　impressive。　The　output　in　book　form　of　other　authorities　followed　rapidly；　and　the　manifest　discrepancies　between　such　teachers　as　Celsus；　Hippocrates；　Galen；　and　Pliny　heightened　still　more　the　growing　spirit　of　criticism。　These　doubts　resulted　in　great　controversies　as　to　the　proper　treatment　of　certain　diseases；　some　physicians　following　Hippocrates；　others　Galen　or　Celsus；　still　others　the　Arabian　masters。　One　of　the　most　bitter　of　these　contests　was　over　the　question　of　〃revulsion；〃　and　〃derivation〃that　is；　whether　in　cases　of　pleurisy　treated　by　bleeding；　the　venesection　should　be　made　at　a　point　distant　from　the　seat　of　the　disease；　as　held　by　the　〃revulsionists；〃　or　at　a　point　nearer　and　on　the　same　side　of　the　body；　as　practised　by　the　〃derivationists。〃　That　any　great　point　for　discussion　could　be　raised　in　the　fifteenth　or　sixteenth　centuries　on　so　simple　a　matter　as　it　seems　to…day　shows　how　necessary　to　the　progress　of　medicine　was　the　discovery　of　the　circulation　of　the　blood　made　by　Harvey　two　centuries　later。　After　Harvey's　discovery　no　such　discussion　could　have　been　possible；　because　this　discovery　made　it　evident　that　as　far　as　the　general　effect　upon　the　circulation　is　concerned；　it　made　little　difference　whether　the　bleeding　was　done　near　a　diseased　part　or　remote　from　it。　But　in　the　sixteenth　century　this　question　was　the　all…absorbing　one　among　t