Собака Баскервіллів

           "Theprobabilityliesinthatdirection. Andifwetakethisasaworkinghypothesiswehaveafreshbasisfromwhichtostartourconstructionofthisunknownvisitor." 

           "Well,then,supposingthat‘C.C.H.’doesstandfor‘CharingCrossHospital,’whatfurtherinferencesmaywedraw?" 

           "Dononesuggestthemselves?Youknowmymethods.Applythem!" 

           "Icanonlythinkoftheobviousconclusionthatthemanhaspractisedintownbeforegoingtothecountry." 

           "Ithinkthatwemightventurealittlefartherthanthis.Lookatitinthislight. Onwhatoccasionwoulditbemostprobablethatsuchapresentationwouldbemade?Whenwouldhisfriendsunitetogivehimapledgeoftheirgoodwill? ObviouslyatthemomentwhenDr.Mortimerwithdrewfromtheserviceofthehospitalinordertostartinpracticeforhimself. Weknowtherehasbeenapresentation. Webelievetherehasbeenachangefromatownhospitaltoacountrypractice.Isit,then,stretchingourinferencetoofartosaythatthepresentationwasontheoccasionofthechange?" 

           "Itcertainlyseemsprobable." 

           "Now,youwillobservethathecouldnothavebeenonthestaffofthehospital,sinceonlyamanwell-establishedinaLondonpracticecouldholdsuchaposition,andsuchaonewouldnotdriftintothecountry. Whatwashe,then?Ifhewasinthehospitalandyetnotonthestaffhecouldonlyhavebeenahouse-surgeonorahouse-physician—littlemorethanaseniorstudent. Andheleftfiveyearsago—thedateisonthestick.