a history of science-1-第55章

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ating　hemorrhage；　as　described　by　Aulus　Cornelius　Celsus　（53　B。C。　to　7　A。D。）。　Hippocrates　and　Hippocratic　writers　treated　hemorrhage　by　application　of　cold；　pressure；　styptics；　and　sometimes　by　actual　cauterizing；　but　they　knew　nothing　of　the　simple　method　of　stopping　a　hemorrhage　by　a　ligature　tied　around　the　bleeding　vessel。　Celsus　not　only　recommended　tying　the　end　of　the　injured　vessel；　but　describes　the　method　of　applying　two　ligatures　before　the　artery　is　divided　by　the　surgeona　common　practice　among　surgeons　at　the　present　time。　The　cut　is　made　between　these　two；　and　thus　hemorrhage　is　avoided　from　either　end　of　the　divided　vessel。　Another　Roman　surgeon；　Heliodorus；　not　only　describes　the　use　of　the　ligature　in　stopping　hemorrhage；　but　also　the　practice　of　torsiontwisting　smaller　vessels；　which　causes　their　lining　membrane　to　contract　in　a　manner　that　produces　coagulation　and　stops　hemorrhage。　It　is　remarkable　that　so　simple　and　practical　a　method　as　the　use　of　the　ligature　in　stopping　hemorrhage　could　have　gone　out　of　use；　once　it　had　been　discovered；　but　during　the　Middle　Ages　it　was　almost　entirely　lost　sight　of；　and　was　not　reintroduced　until　the　time　of　Ambroise　Pare；　in　the　sixteenth　century。　Even　at　a　very　early　period　the　Romans　recognized　the　advantage　of　surgical　methods　on　the　field　of　battle。　Each　soldier　was　supplied　with　bandages；　and　was　probably　instructed　in　applying　them；　something　in　the　same　manner　as　is　done　now　in　all　modern　armies。　The　Romans　also　made　use　of　military　hospitals　and　had　established　a　rude　but　very　practical　field…ambulance　service。　〃In　every　troop　or　bandon　of　two　or　four　hundred　men；　eight　or　ten　stout　fellows　were　deputed　to　ride　immediately　behind　the　fighting…line　to　pick　up　and　rescue　the　wounded；　for　which　purpose　their　saddles　had　two　stirrups　on　the　left　side；　while　they　themselves　were　provided　with　water…flasks；　and　perhaps　applied　temporary　bandages。　They　were　encouraged　by　a　reward　of　a　piece　of　gold　for　each　man　they　rescued。　'Noscomi'　were　male　nurses　attached　to　the　military　hospitals；　but　not　inscribed　'on　strength'　of　the　legions；　and　were　probably　for　the　most　part　of　the　servile　class。〃＇6＇　From　the　time　of　the　early　Alexandrians；　Herophilus　and　Erasistratus；　whose　work　we　have　already　examined；　there　had　been　various　anatomists　of　some　importance　in　the　Alexandrian　school；　though　none　quite　equal　to　these　earlier　workers。　The　best…known　names　are　those　of　Celsus　（of　whom　we　have　already　spoken）；　who　continued　the　work　of　anatomical　investigation；　and　Marinus；　who　lived　during　the　reign　of　Nero；　and　Rufus　of　Ephesus。　Probably　all　of　these　would　have　been　better　remembered　by　succeeding　generations　had　their　efforts　not　been　eclipsed　by　those　of　Galen。　This　greatest　of　ancient　anatomists　was　born　at　Pergamus　of　Greek　parents。　His　father；　Nicon；　was　an　architect　and　a　man　of　considerable　ability。　Until　his　fifteenth　year　the　youthful　Galen　was　instructed　at　home；　chiefly　by　his　father；　but　after　that　time　he　was　placed　under　suitable　teachers　for　instruction　in　the　philosophical　systems　in　vogue　at　that　period。　Shortly　after　this；　however；　the　superstitious　Nicon；　following　the　interpretations　of　a　dream；　decided　that　his　son　should　take　up　the　study　of　medicine；　and　placed　him　under　the　instruction　of　several　learned　physicians。　Galen　was　a　tireless　worker；　making　long　tours　into　Asia　Minor　and　Palestine　to　improve　himself　in　pharmacology；　and　studying　anatomy　for　some　time　at　Alexandria。　He　appears　to　have　been　full　of　the　superstitions　of　the　age；　however；　and　early　in　his　career　made　an　extended　tour　into　western　Asia　in　search　of　the　chimerical　〃jet…stone〃a　stone　possessing　the　peculiar　qualities　of　〃burning　with　a　bituminous　odor　and　supposed　to　possess　great　potency　in　curing　such　diseases　as　epilepsy；　hysteria；　and　gout。〃　By　the　time　he　had　reached　his　twenty…eighth　year　he　had　perfected　his　education　in　medicine　and　returned　to　his　home　in　Pergamus。　Even　at　that　time　he　had　acquired　considerable　fame　as　a　surgeon；　and　his　fellow…citizens　showed　their　confidence　in　his　ability　by　choosing　him　as　surgeon　to　the　wounded　gladiators　shortly　after　his　return　to　his　native　city。　In　these　duties　his　knowledge　of　anatomy　aided　him　greatly；　and　he　is　said　to　have　healed　certain　kinds　of　wounds　that　had　previously　baffled　the　surgeons。　In　the　time　of　Galen　dissections　of　the　human　body　were　forbidden　by　law；　and　he　was　obliged　to　confine　himself　to　dissections　of　the　lower　animals。　He　had　the　advantage；　however；　of　the　anatomical　works　of　Herophilus　and　Erasistratus；　and　he　must　have　depended　upon　them　in　perfecting　his　comparison　between　the　anatomy　of　men　and　the　lower　animals。　It　is　possible　that　he　did　make　human　dissections　surreptitiously；　but　of　this　we　have　no　proof。　He　was　familiar　with　the　complicated　structure　of　the　bones　of　the　cranium。　He　described　the　vertebrae　clearly；　divided　them　into　groups；　and　named　them　after　the　manner　of　anatomists　of　to…day。　He　was　less　accurate　in　his　description　of　the　muscles；　although　a　large　number　of　these　were　described　by　him。　Like　all　anatomists　before　the　time　of　Harvey；　he　had　a　very　erroneous　conception　of　the　circulation；　although　he　understood　that　the　heart　was　an　organ　for　the　propulsion　of　blood；　and　he　showed　that　the　arteries　of　the　living　animals　did　not　contain　air　alone；　as　was　taught　by　many　anatomists。　He　knew；　also；　that　the　heart　was　made　up　of　layers　of　fibres　that　ran　in　certain　fixed　directionsthat　is；　longitudinal；　transverse；　and　oblique；　but　he　did　not　recognize　the　heart　as　a　muscular　organ。　In　proof　of　this　he　pointed　out　that　all　muscles　require　rest；　and　as　the　heart　did　not　rest　it　could　not　be　composed　of　muscular　tissue。　Many　of　his　physiological　experiments　were　conducted　upon　scientific　principles。　Thus　he　proved　that　certain　muscles　were　under　the　control　of　definite　sets　of　nerves　by　cutting　these　nerves　in　living　animals；　and　observing　that　the　muscles　supplied　by　them　were　rendered　useless。　He　pointed　out　also　that　nerves　have　no　power　in　themselves；　but　merely　conduct　impulses　to　and　from　the　brain　and　spinal…cord。　He　turned　this　peculiar　knowledge　to　account　in　the　case　of　a　celebrated　sophist；　Pausanias；　who　had　been　under　the　treatment　of　various　physicians　for　a　numbness　in　the　fourth　and　fifth　fingers　of　his　left　hand。　These　physicians　had　been　treating　this　condition　by　applications　of　poultices　to　the　hand　itself。　Galen；　being　called　in　consultation；　pointed　out　that　the　injury　was　probably　not　in　the　hand　itself；　but　in　the　ulner　nerve；　which　controls　sensation　in　the　fourth　and　fifth　fingers。　Surmising　that　the　nerve　must　have　been　injured　in　some　way；　he　made　careful　inquiries　of　the　patient；　who　recalled　that　he　had　been　thrown　from　his　chariot　some　time　before；　striking　and　injuring　his　back。　Acting　upon　this　information；　Galen　applied　stimulating　remedies　to　the　source　of　the　nerve　itselfthat　is；　to　the　bundle　of　nerve…trunks　known　as　the　brachial　plexus；　in　the　shoulder。　To　the　surprise　and　confusion　of　his　fellow…physicians；　this　method　of　treatment　proved　effective　and　the　patient　recovered　completely　in　a　short　time。　Although　the　functions　of　the　organs　in　the　chest　were　not　well　understood　by　Galen；　he　was　well　acquainted　with　their　anatomy。　He　knew　that　the　lungs　were　covered　by　thin　membrane；　and　that　the　heart　was　surrounded　by　a　sac　of　very　similar　tissue。　He　made　constant　comparisons　also　between　these　organs　in　different　animals；　as　his　dissections　were　performed　upon　beasts　ranging　in　size　from　a　mouse　to　an　elephant。　The　minuteness　of　his　observations　is　shown　by　the　fact　that　he　had　noted　and　described　the　ring　of　bone　found　in　the　hearts　of　certain　animals；　such　as　the　horse；　although　not　found　in　the　human　heart　or　in　most　animals。　His　description　of　the　abdominal　organs　was　in　general　accurate。　He　had　noted　that　the　abdominal　cavity　was　lined　with　a　peculiar　saclike　membrane；　the　peritoneum；　which　also　surrounded　most　of　the　organs　contained　in　the　cavity；　and　he　made　special　note　that　this　membrane　also　enveloped　the　liver　in　a　peculiar　manner。　The　exactness　of　the　last　observation　seems　the　more　wonderful　when　we　reflect　that　even　to…day　the　medical；　student