inted　by　Surgeon…General　Sternberg　（himself　one　of　the　most　energetic　students　of　the　disease）　undertook　fresh　investigations。　　Dr。　Walter　Reed；　Professor　of　Bacteriology　in　the　Army　Medical　School；　was　placed　in　charge：　Dr。　Carroll　of　the　United　States　Army；　Dr。　Agramonte　of　Havana　and　Dr。　Jesse　W。　Lazear　were　the　other　members。　At　the　Johns　Hopkins　Hospital；　we　were　deeply　interested　in　the　work；　as　Dr。　Walter　Reed　was　a　favorite　pupil　of　Professor　Welch；　a　warm　friend　of　all　of　us；　and　a　frequent　visitor　to　our　laboratories。　Dr。　Jesse　Lazear；　who　had　been　my　house　physician；　had　worked　with　Dr。　Thayer　and　myself　at　malaria；　and　gave　up　the　charge　of　my　clinical　laboratory　to　join　the　commission。
  ＇5＇　Matthew　Carey：　　A　Short　Account　of　the　Malignant　Fever；　Philadelphia；　1793。
  ＇6＇　R。　La　Roche：　　Yellow　Fever；　2　vols。；　Philadelphia；　1855。
  Many　scientific　discoveries　have　afforded　brilliant　illustrations　of　method　in　research；　but　in　the　work　of　these　men　one　is　at　a　loss　to　know　which　to　admire　morethe　remarkable　accuracy　and　precision　of　the　experiments；　or　the　heroism　of　the　menofficers　and　rank　and　file　of　the　United　States　Army；　they　knew　all　the　time　that　they　were　playing　with　death；　and　some　of　them　had　to　pay　the　penalty！　The　demonstration　was　successfulbeyond　peradventurethat　yellow　fever　could　be　transmitted　by　mosquitoes；　and　equally　the　negative　proposition　that　it　could　not　be　transmitted　by　fomites。　　An　interval　of　twelve　or　more　days　was　found　to　be　necessary　after　the　mosquito　has　bitten　a　yellow　fever　patient　before　it　is　capable　of　transmitting　the　infection。　Lazear　permitted　himself　to　be　bitten　by　a　stray　mosquito　while　conducting　his　experiments　in　the　yellow　fever　hospital。　　Bitten　on　the　thirteenth；　he　sickened　on　the　eighteenth　and　died　on　the　twenty…fifth　of　September；　but　not　until　he　had　succeeded　in　showing　in　two　instances　that　mosquitoes　could　convey　the　infection。　　He　added　another　to　the　long　list　of　members　of　the　profession　who　have　laid　down　their　lives　in　search　of　the　causes　of　disease。　　Of　such　men　as　Lazear　and　of　Myers　of　the　Liverpool　Yellow…Fever　Commission；　Dutton　and　young　Manson；　may　fitly　be　sung　from　the　noblest　of　American　poems　the　tribute　which　Lowell　paid　to　Harvard's　sons　who　fell　in　the　War　of　Secession：
  Many　in　sad　faith　sought　for　her；　　Many　with　crossed　hands　sighed　for　her；　　But　these；　our　brothers；　fought　for　her；　　At　life's　dear　peril　wrought　for　her；　　So　loved　her　that　they　died　for　her。
  Fortunately；　the　commander…in…chief　at　the　time　in　Cuba　was　General　Leonard　Wood；　who　had　been　an　army　surgeon；　and　he　was　the　first　to　appreciate　the　importance　of　the　discovery。　The　sanitation　of　Havana　was　placed　in　the　hands　of　Dr。　Gorgas；　and　within　nine　months　the　city　was　cleared　of　yellow　fever；　and；　with　the　exception　of　a　slight　outbreak　after　the　withdrawal　of　the　American　troops；　has　since　remained　free　from　a　disease　which　had　been　its　scourge　for　centuries。　　As　General　Wood　remarked；　〃Reed's　discovery　has　resulted　in　the　saving　of　more　lives　annually　than　were　lost　in　the　Cuban　War；　and　saves　the　commercial　interest　of　the　world　a　greater　financial　loss　each　year　than　the　cost　of　the　Cuban　War。　　He　came　to　Cuba　at　a　time　when　one　third　of　the　officers　of　my　staff　died　of　yellow　fever；　and　we　were　discouraged　at　the　failure　of　our　efforts　to　control　it。〃　Following　the　example　of　Havana　other　centres　were　attacked；　at　Vera　Cruz　and　in　Brazil；　with　the　same　success；　and　it　is　safe　to　say　that　now；　thanks　to　the　researches　of　Reed　and　his　colleagues；　with　proper　measures；　no　country　need　fear　a　paralyzing　outbreak　of　this　once　dreaded　disease。
  The　scientific　researches　in　the　last　two　decades　of　the　nineteenth　century　made　possible　the　completion　of　the　Panama　Canal。　　The　narrow　isthmus　separating　the　two　great　oceans　and　joining　the　two　great　continents；　has　borne　for　four　centuries　an　evil　repute　as　the　White　Man's　Grave。　　Silent　upon　a　peak　of　Darien；　stout　Cortez　with　eagle　eye　had　gazed　on　the　Pacific。　　As　early　as　1520；　Saavedra　proposed　to　cut　a　canal　through　the　Isthmus。　　There　the　first　city　was　founded　by　the　conquerors　of　the　new　world；　which　still　bears　the　name　of　Panama。　　Spaniards；　English　and　French　fought　along　its　coasts；　to　it　the　founder　of　the　Bank　of　England　took　his　ill…fated　colony；　Raleigh；　Drake；　Morgan　the　buccaneer；　and　scores　of　adventurers　seeking　gold；　found　in　fever　an　enemy　stronger　than　the　Spaniard。　　For　years　the　plague…stricken　Isthmus　was　abandoned　to　the　negroes　and　the　half…breeds；　until　in　1849；　stimulated　by　the　gold　fever　of　California；　a　railway　was　begun　by　the　American　engineers；　Totten　and　Trautwine；　and　completed　in　1855；　a　railway　every　tie　of　which　cost　the　life　of　a　man。　The　dream　of　navigators　and　practical　engineers　was　taken　in　hand　by　Ferdinand　de　Lesseps　in　January；　1881。　　The　story　of　the　French　Canal　Company　is　a　tragedy　unparalleled　in　the　history　of　finance；　and；　one　may　add；　in　the　ravages　of　tropical　disease。　Yellow　fever；　malaria；　dysentery；　typhus；　carried　off　in　nine　years　nearly　twenty　thousand　employees。　　The　mortality　frequently　rose　above　100；　sometimes　to　130；　140　and　in　September；　1885；　it　reached　the　appalling　figure　of　176。97　per　thousand　work　people。　This　was　about　the　maximum　death　rate　of　the　British　Army　in　the　West　Indies　in　the　nineteenth　century。
  When；　in　1904；　the　United　States　undertook　to　complete　the　Canal；　everyone　felt　that　the　success　or　failure　was　largely　a　matter　of　sanitary　control。　　The　necessary　knowledge　existed；　but　under　the　circumstances　could　it　be　made　effective？　　Many　were　doubtful。　Fortunately；　there　was　at　the　time　in　the　United　States　Army　a　man　who　had　already　served　an　apprenticeship　in　Cuba；　and　to　whom　more　than　to　anyone　else　was　due　the　disappearance　of　yellow　fever　from　that　island。　To　a　man；　the　profession　in　the　United　States　felt　that　could　Dr。　Gorgas　be　given　full　control　of　the　sanitary　affairs　of　the　Panama　Zone；　the　health　problem；　which　meant　the　Canal　problem；　could　be　solved。　There　was　at　first　a　serious　difficulty　relating　to　the　necessary　administrative　control　by　a　sanitary　officer。　　In　an　interview　which　Dr。　Welch　and　I　had　with　President　Roosevelt；　he　keenly　felt　this　difficulty　and　promised　to　do　his　best　to　have　it　rectified。　It　is　an　open　secret　that　at　first；　as　was　perhaps　only　natural；　matters　did　not　go　very　smoothly；　and　it　took　a　year　or　more　to　get　properly　organized。　Yellow　fever　recurred　on　the　Isthmus　in　1904　and　in　the　early　part　of　1905。　It　was　really　a　colossal　task　in　itself　to　undertake　the　cleaning　of　the　city　of　Panama；　which　had　been　for　centuries　a　pest…house；　the　mortality　in　which；　even　after　the　American　occupation；　reached　during　one　month　the　rate　of　71　per　thousand　living。　There　have　been　a　great　many　brilliant　illustrations　of　the　practical　application　of　science　in　preserving　the　health　of　a　community　and　in　saving　life；　but　it　is　safe　to　say　that；　considering　the　circumstances；　the　past　history；　and　the　extraordinary　difficulties　to　be　overcome；　the　work　accomplished　by　the　Isthmian　Canal　Commission　is　unique。　The　year　1905　was　devoted　to　organization；　yellow　fever　was　got　rid　of；　and　at　the　end　of　the　year　the　total　mortality　among　the　whites　had　fallen　to　8　per　thousand；　but　among　the　blacks　it　was　still　high；　44。　For　three　years；　with　a　progressively　increasing　staff　which　had　risen　to　above　40；000；　of　whom　more　than　12；000　were　white；　the　death　rate　progressively　fell。
  Of　the　six　important　tropical　diseases；　plague；　which　reached　the　Isthmus　one　year；　was　quickly　held　in　check。　　Yellow　fever；　the　most　dreaded　of　them　all；　never　recurred。　　Beri…beri；　which　in　1906　caused　sixty…eight　deaths；　has　gradually　disappeared。　The　hookworm　disease；　ankylostomiasis；　has　steadily　decreased。　From　the　very　outset；　malaria　has　been　taken　as　the　measure　of　sanitary　efficiency。　　Throughout　the　French　occupation　it　was　the　chief　enemy　to　be　considered；　not　only　because　of　its　fatality；　but　on　account　of　the　prolonged　incapacity　following　infection。　In　1906；　out　of　every　1000　employees　there　were　admitted　to　the　hospital　from　malaria　821；　in　1907；　424；　in　1908；　282；　in　1912；　110；　in　1915；　51；　in　1917；　14。　　The　fatalities　from　the　disease　have　fallen　from　233　in　1906　to　154　in　1907；　to　73　in　1908　and　to　7　in　1914。　　The　death　rate　for　malarial　fever　per　1000　population　sank　from　8。49　in　1906　to　0。11　in　1918。　Dysentery；　next　to　malaria　the　most　serious　of　the　tropical　diseases　in　the　Zone；　caused　69　deaths　in　1906；　48　in　1907；　in　1908；　with　nearly　44；000；　only　16　deaths；　and　in　1914；　4。＇*＇　But　it　is　when　the　general　figures　are　taken　that　we　see　the　extraordinary　reduction　that　has　taken　place。　Out　of　every　1000　engaged　in　1908　only　a　third　of　the　number　died　that　died　in　1906；　and　half　the　number　that　died　in　1907。
  ＇*＇　Figures　for　recent　years　supplied　by　editors。
  In　1914；　the　death　rate　from　disease　among　white　males　had　fallen　to　3。13　per　thousand。　　The　rate　among　the　2674　American　women　and　children　connected　with　the　Commission　was　only　9。72　per　thousand。　But　by　far　the　most　gratifying　reduction　is　among　the　blacks；　among　whom　the　rate　from　disease　had　fallen　to　the　surprisingly　low　figure　in　1912　of　8。77　per　thous