ns；corrupters　of　the　race；　whom　he　would　have　banished　from　the　city；then　he　sketches　the　career　of　some　of　the　more　famous　of　the　physicians　under　the　Empire；　some　of　whom　must　have　had　incomes　never　approached　at　any　other　period　in　the　history　of　medicine。　　The　chapter　gives　a　good　picture　of　the　stage　on　which　Galen　（practically　a　contemporary　of　Pliny）　was　to　play　so　important　a　role。　Pliny　seems　himself　to　have　been　rather　disgusted　with　the　devious　paths　of　the　doctors　of　his　day；　and　there　is　no　one　who　has　touched　with　stronger　language　upon　the　weak　points　of　the　art　of　physic。　In　one　place　he　says　that　it　alone　has　this　peculiar　art　and　privilege；　〃That　whosoever　professeth　himself　a　physician；　is　straightwaies　beleeved；　say　what　he　will：　　and　yet　to　speake　a　truth；　there　are　no　lies　dearer　sold　or　more　daungerous　than　those　which　proceed　out　of　a　Physician's　mouth。　Howbeit；　we　never　once　regard　or　look　to　that；　so　blind　we　are　in　our　deepe　persuasion　of　them；　and　feed　our　selves　each　one　in　a　sweet　hope　and　plausible　conceit　of　our　health　by　them。　　Moreover；　this　mischief　there　is　besides；　That　there　is　no　law　or　statute　to　punish　the　ignorance　of　blind　Physicians；　though　a　man　lost　his　life　by　them：　　neither　was　there　ever　any　man　knowne；　who　had　revenge　of　recompence　for　the　evill　intreating　or　misusage　under　their　hands。　　They　learne　their　skill　by　endaungering　our　lives：　and　to　make　proofe　and　experiments　of　their　medicines；　they　care　not　to　kill　us。〃＇35＇　He　says　it　is　hard　that；　while　the　judges　are　carefully　chosen　and　selected；　physicians　are　practically　their　own　judges；　and　that　of　the　men　who　may　give　us　a　quick　despatch　and　send　us　to　Heaven　or　Hell；　no　enquiry　or　examination　is　made　of　their　quality　and　worthiness。　It　is　interesting　to　read　so　early　a　bitter　criticism　of　the　famous　〃Theriaca；〃　a　great　compound　medicine　invented　by　Antiochus　III；　which　had　a　vogue　for　fifteen　hundred　years。
  ＇34＇　Bk。　VIII；　Chap。　VII。
  ＇35＇　Pliny：　　Natural　History　（XXIX；　1）；　Philemon　Holland's　version；　London；　1601；　II；　347。
  But　we　must　return　to　Galen　and　his　works；　which　comprise　the　most　voluminous　body　of　writings　left　by　any　of　the　ancients。　The　great　edition　is　that　in　twenty…two　volumes　by　Kuhn　（1821…1833）。　The　most　useful　editions　are　the　〃Juntines〃　of　Venice；　which　were　issued　in　thirteen　editions。　　In　the　fourth　and　subsequent　editions　a　very　useful　index　by　Brassavola　is　included。　A　critical　study　of　the　writings　is　at　present　being　made　by　German　scholars　for　the　Prussian　Academy；　which　will　issue　a　definitive　edition　of　his　works。
  Galen　had　an　eclectic　mind　and　could　not　identify　himself　with　any　of　the　prevailing　schools；　but　regarded　himself　as　a　disciple　of　Hippocrates。　　For　our　purpose；　both　his　philosophy　and　his　practice　are　of　minor　interest　in　comparison　with　his　great　labors　in　anatomy　and　physiology。
  In　anatomy；　he　was　a　pupil　of　the　Alexandrians　to　whom　he　constantly　refers。　Times　must　have　changed　since　the　days　of　Herophilus；　as　Galen　does　not　seem　ever　to　have　had　an　opportunity　of　dissecting　the　human　body；　and　he　laments　the　prejudice　which　prevents　it。　　In　the　study　of　osteology；　he　urges　the　student　to　be　on　the　lookout　for　an　occasional　human　bone　exposed　in　a　graveyard；　and　on　one　occasion　he　tells　of　finding　the　carcass　of　a　robber　with　the　bones　picked　bare　by　birds　and　beasts。　Failing　this　source；　he　advises　the　student　to　go　to　Alexandria；　where　there　were　still　two　skeletons。　　He　himself　dissected　chiefly　apes　and　pigs。　His　osteology　was　admirable；　and　his　little　tractate　〃De　Ossibus〃　could；　with　very　few　changes；　be　used　today　by　a　hygiene　class　as　a　manual。　His　description　of　the　muscles　and　of　the　organs　is　very　full；　covering；　of　course；　many　sins　of　omission　and　of　commission；　but　it　was　the　culmination　of　the　study　of　the　subject　by　Greek　physicians。
  His　work　as　a　physiologist　was　even　more　important；　for；　so　far　as　we　know；　he　was　the　first　to　carry　out　experiments　on　a　large　scale。　　In　the　first　place；　he　was　within　an　ace　of　discovering　the　circulation　of　the　blood。　You　may　remember　that　through　the　errors　of　Praxagoras　and　Erasistratus；　the　arteries　were　believed　to　contain　air　and　got　their　name　on　that　account：　Galen　showed　by　experiment　that　the　arteries　contain　blood　and　not　air。　He　studied　particularly　the　movements　of　the　heart；　the　action　of　the　valves；　and　the　pulsatile　forces　in　the　arteries。　　Of　the　two　kinds　of　blood；　the　one；　contained　in　the　venous　system；　was　dark　and　thick　and　rich　in　grosser　elements；　and　served　for　the　general　nutrition　of　the　body。　This　system　took　its　origin；　as　is　clearly　shown　in　the　figure；　in　the　liver；　the　central　organ　of　nutrition　and　of　sanguification。　From　the　portal　system　were　absorbed；　through　the　stomach　and　intestines；　the　products　of　digestion。　　From　the　liver　extend　the　venae　cavae；　one　to　supply　the　head　and　arms；　the　other　the　lower　extremities：　extending　from　the　right　heart　was　a　branch；　corresponding　to　the　pulmonary　artery；　the　arterial　vein　which　distributed　blood　to　the　lungs。　This　was　the　closed　venous　system。　　The　arterial　system；　shown；　as　you　see；　quite　separate　in　Figure　31；　was　full　of　a　thinner；　brighter；　warmer　blood；　characterized　by　the　presence　of　an　abundance　of　the　vital　spirits。　Warmed　in　the　ventricle；　it　distributed　vital　heat　to　all　parts　of　the　body。　The　two　systems　were　closed　and　communicated　with　each　other　only　through　certain　pores　or　perforations　in　the　septum　separating　the　ventricles。　At　the　periphery；　however；　Galen　recognized　（as　had　been　done　already　by　the　Alexandrians）　that　the　arteries　anastomose　with　the　veins；　〃。　。　。　and　they　mutually　receive　from　each　other　blood　and　spirits　through　certain　invisible　and　extremely　small　vessels。〃
  It　is　difficult　to　understand　how　Galen　missed　the　circulation　of　the　blood。　He　knew　that　the　valves　of　the　heart　determined　the　direction　of　the　blood　that　entered　and　left　the　organ；　but　he　did　not　appreciate　that　it　was　a　pump　for　distributing　the　blood；　regarding　it　rather　as　a　fireplace　from　which　the　innate　heat　of　the　body　was　derived。　He　knew　that　the　pulsatile　force　was　resident　in　the　walls　of　the　heart　and　in　the　arteries；　and　he　knew　that　the　expansion；　or　diastole；　drew　blood　into　its　cavities；　and　that　the　systole　forced　blood　out。　Apparently　his　view　was　that　there　was　a　sort　of　ebb　and　flow　in　both　systemsand　yet；　he　uses　language　just　such　as　we　would；　speaking　of　the　venous　system　as　〃。　。　。　a　conduit　full　of　blood　with　a　multitude　of　canals　large　and　small　running　out　from　it　and　distributing　blood　to　all　parts　of　the　body。〃　　He　compares　the　mode　of　nutrition　to　irrigating　canals　and　gardens；　with　a　wonderful　dispensation　by　nature　that　they　should　〃neither　lack　a　sufficient　quantity　of　blood　for　absorption　nor　be　overloaded　at　any　time　with　excessive　supply。〃　The　function　of　respiration　was　the　introduction　of　the　pneuma；　the　spirits　which　passed　from　the　lungs　to　the　heart　through　the　pulmonary　vessels。　Galen　went　a　good　deal　beyond　the　idea　of　Aristotle；　reaching　our　modern　conception　that　the　function　is　to　maintain　the　animal　heat；　and　that　the　smoky　matters　derived　from　combustion　of　the　blood　are　discharged　by　expiration。
  I　have　dwelt　on　these　points　in　Galen's　physiology；　as　they　are　fundamental　in　the　history　of　the　circulation；　and　they　are　sufficient　to　illustrate　his　position。　Among　his　other　brilliant　experiments　were　the　demonstration　of　the　function　of　the　laryngeal　nerves；　of　the　motor　and　sensory　functions　of　the　spinal　nerve　roots；　of　the　effect　of　transverse　incision　of　the　spinal　cord；　and　of　the　effect　of　hemisection。　Altogether　there　is　no　ancient　physician　in　whose　writings　are　contained　so　many　indications　of　modern　methods　of　research。
  Galen's　views　of　disease　in　general　are　those　of　Hippocrates；　but　he　introduces　many　refinements　and　subdivisions　according　to　the　predominance　of　the　four　humors；　the　harmonious　combination　of　which　means　health；　or　eucrasia；　while　their　perversion　or　improper　combination　leads　to　dyscrasia；　or　ill　health。　In　treatment　he　had　not　the　simplicity　of　Hippocrates：　he　had　great　faith　in　drugs　and　collected　plants　from　all　parts　of　the　known　world；　for　the　sale　of　which　he　is　said　to　have　had　a　shop　in　the　neighborhood　of　the　Forum。　　As　I　mentioned；　he　was　an　eclectic；　held　himself　aloof　from　the　various　schools　of　the　day；　calling　no　man　master　save　Hippocrates。　　He　might　be　called　a　rational　empiricist。　He　made　war　on　the　theoretical　practitioners　of　the　day；　particularly　the　Methodists；　who；　like　some　of　their　modern　followers；　held　that　their　business　was　with　the　disease　and　not　with　the　conditions　out　of　which　it　arose。
  No　other　physician　has　ever　occupied　the　commanding　position　of　〃Clarissimus〃　Galenus。　　For　fifteen　centuries　he　dominated　medical　thought　as　powerfully　as　did　Aristotle　in　the　schools。　Not　until　the　Renaissance　did　daring　spirits　begin　to　question　the　infallibility　of　this　medical　pope。　　But　here　we　must　part　with　the　last　and；　in　many　ways；　the　greatest　of　the　Greeks　a　man　very　much　of　our　own　type；　who；　could　he　visit　this　country　today；　might　teach　us　many　lessons。　　He　would　smile　in　scorn　at　the　water　supply　of　many　of　our　cities；　thinking　of