Thereasonwhyweteachsomuchthatisnotpracticalandinitselfuseful，isbecausewefindthattheeasiestwayofteachingwhatispracticalanduseful。Ifwecouldinanywayeliminateallthatwouldhelpamantodealsuccessfullywithdisease，andteachitbyitselfsothatitshouldbeastenaciouslyrootedinthememory，aseasilysummonedwhenwanted，asfertileinsuggestionofrelatedfacts，assatisfactorytotheperemptorydemandsoftheintelligenceasiftaughtinitsscientificconnections，Ithinkitwouldbeourdutysototeachthemomentoustruthsofmedicine，andtoregardalluselessadditionsasanintrusiononthetimewhichshouldbeotherwiseoccupied。
　　Butwecannotsuccessfullyeliminateandteachbyitselfthatwhichispurelypractical。Theeasiestandsurestwhyofacquiringfactsistolearnthemingroups，insystems，andsystematizedknowledgeisscience。Youcanveryoftencarrytwofactsfastenedtogethermoreeasilythanonebyitself，asahousemaidcancarrytwopailsofwaterwithahoopmoreeasilythanonewithoutit。Youcanrememberaman’sface，madeupofmanyfeatures，betterthanyoucanhisnoseorhismouthorhiseye-brow。Scoresofproverbsshowyouthatyoucanremembertwolinesthatrhymebetterthanonewithoutthejingle。
　　Theancients，whoknewthelawsofmemory，groupedthesevencitiesthatcontendedforthehonorofbeingHomer’sbirthplaceinalinethusgivenbyAulusGellius：
　　Smurna，Rodos，Colophon，Salamin，Ios，Argos，Athenai。
　　Iremember，intheearlierpoliticaldaysofMartinVanBuren，thatColonelStone，ofthe“NewYorkCommercial，“oroneofhiscorrespondents，saidthatsixtownsofNewYorkwouldclaiminthesamewaytohavebeenthebirth-placeofthe“LittleMagician，“ashewasthencalled；andthushegavetheirnames，anyoneofwhichI
　　shouldlongagohaveforgotten，butwhichasagrouphavestucktightinmymemoryfromthatdaytothis；
　　Catskill，Saugerties，Redhook，Kinderhook，Scaghticoke，Schodac。
　　Ifthememorygainssomuchbymererhythmicalassociation，howmuchmorewillitgainwhenisolatedfactsarebroughttogetherunderlawsandprinciples，whenorgansareexaminedintheirnaturalconnections，whenstructureiscoupledwithfunction，andhealthyanddiseasedactionarestudiedastheypassoneintotheother！
　　Systematic，orscientificstudyisinvaluableassupplyinganaturalkindofmnemonics，iffornothingelse。YoucannotproperlylearnthefactsyouwantfromAnatomyandChemistryinanywaysoeasilyasbytakingthemintheirregularorder，withotheralliedfacts，onlytheremustbecommonsenseexercisedinleavingoutagreatdealwhichbelongstoeachofthetwobranchesaspurescience。Thedullestofteachersistheonewhodoesnotknowwhattoomit。
　　Thelargeraimofscientifictrainingistofurnishyouwithprinciplestowhichyouwillbeabletoreferisolatedfacts，andsobringthesewithintherangeofrecordedexperience。Seewhatthe“LondonTimes“saidaboutthethreeGermanswhocrackedopenJohnBullChatwood’sstrong-boxattheFairtheotherday，whilethethreeEnglishmenhammeredawayinvainatBrotherJonathanHerring’s。TheEnglishmenrepresentedbruteforce。TheGermanshadbeentrainedtoappreciateprinciple。TheEnglishman“knowshisbusinessbyroteandruleofthumb“——science，whichwould“teachhimtodoinanhourwhathashithertooccupiedhimtwohours，““isinamannerforbiddentohim。“Tothiscausethe“Times“attributesthefallingoffofEnglishworkmenincomparisonwiththoseoftheContinent。
　　Grantingallthis，wemustnotexpecttoomuchfrom“science“asdistinguishedfromcommonexperience。Therearetenthousandexperimenterswithoutspecialapparatusforeveryoneinthelaboratory。Accidentisthegreatchemistandtoxicologist。Battleisthegreatvivisector。HungerhasinstitutedresearchesonfoodsuchasnoLiebig，noAcademicCommissionhaseverrecorded。
　　Medicine，sometimesimpertinently，oftenignorantly，oftencarelesslycalled“allopathy，“appropriateseverythingfromeverysourcethatcanbeoftheslightestusetoanybodywhoisailinginanyway，orliketobeailingfromanycause。Itlearnedfromamonkhowtouseantimony，fromaJesuithowtocureagues，fromafriarhowtocutforstone，fromasoldierhowtotreatgout，fromasailorhowtokeepoffscurvy，fromapostmasterhowtosoundtheEustachiantube，fromadairy-maidhowtopreventsmall-pox，andfromanoldmarket-
　　womanhowtocatchtheitch-insect。ItborrowedacupunctureandthemoxafromtheJapaneseheathen，andwastaughttheuseoflobeliabytheAmericansavage。Itstandsreadyto-daytoacceptanythingfromanytheorist，fromanyempiricwhocanmakeoutagoodcaseforhisdiscoveryorhisremedy。“Science“isoneofitsbenefactors，butonlyone，outofmany。Askthewisestpractisingphysicianyouknow，whatbranchesofsciencehelphimhabitually，andwhatamountofknowledgerelatingtoeachbranchherequiresforhisprofessionalduties。Hewilltellyouthatscientifictraininghasavalueindependentofallthespecialknowledgeacquired。Hewilltellyouthatmanyfactsareexplainedbystudyingtheminthewiderrangeofrelatedfactstowhichtheybelong。Hewillgratefullyrecognizethattheanatomisthasfurnishedhimwithindispensabledata，thatthephysiologisthassometimesputhimonthetrackofnewmodesoftreatment，thatthechemisthasisolatedtheactiveprinciplesofhismedicines，hastaughthimhowtocombinethem，hasfromtimetotimeofferedhimnewremedialagencies，andsoofothersofhisallies。
　　Buthewillalsotellyou，ifIamnotmistaken，thathisownbranchofknowledgeissoextensiveandsoperplexingthathemustacceptmostofhisfactsreadymadeattheirhands。Hewillowntoyouthatinthestruggleforlifewhichgoesondayandnightinourthoughtsasintheoutsideworldofnature，muchthathelearnedunderthenameofsciencehasdiedout，andthatsimplehomelyexperiencehaslargelytakentheplaceofthatscholasticknowledgetowhichheandperhapssomeofhisinstructorsonceattachedaparemountimportance。
　　This，then，ismyviewofscientifictrainingasconductedincoursessuchasyouareenteringon。UptoacertainpointIbelieveinsetLecturesasexcellentadjunctstowhatisfarmoreimportant，practicalinstructionatthebedside，intheoperatingroom，andundertheeyeoftheDemonstrator。ButIamsofarfromwishingthesecoursesextended，thatIthinksomeofthem——supposeIsaymyown——wouldalmostbearcurtailing。Doyouwantmetodescribemorebranchesofthesciaticandcruralnerves？IcantakeFischer’splates，andlecturingonthatscalefillupmywholecourseandnotfinishthenervesalone。Wemuststopsomewhere，andformyownpartIthinkthescholasticexercisesofourcollegeshavealreadyclaimedtheirfullshareofthestudent’stimewithoutourseekingtoextendthem。
　　ItrustIhavevindicatedtheapparentinconsequenceofteachingyoungstudentsagooddealthatseemsatfirstsightprofitless，butwhichhelpsthemtolearnandretainwhatisprofitable。Butthisisaninquisitiveage，andifweinsistonpilingupbeyondacertainheightknowledgewhichisinitselfmeretrashandlumbertoamanwhoselifeistobeonelongfightwithdeathanddisease，therewillbesomesharpquestionsaskedbyandby，andourquick-wittedpeoplewillperhapsfindtheycangetalongaswellwithouttheprofessor’scapaswithoutthebishop’smitreandthemonarch’scrown。
　　Imyselfhavenothingtodowithclinicalteaching。YetIdonothesitatetosayitismoreessentialthanalltherestputtogether，sofarastheordinarypracticeofmedicineisconcerned；andthisisbyfarthemostimportantthingtobelearned，becauseitdealswithsomanymorelivesthananyotherbranchoftheprofession。Soofpersonalinstruction，suchaswegiveandothersgiveintheintervaloflectures，muchofitatthebedside，someofitinthelaboratory，someinthemicroscope-room，someintherecitation-room，Ithinkithasmanyadvantagesofitsownoverthewintercourse，andIdonotwishtoseeitshortenedforthesakeofprolongingwhatseemstomelongenoughalready。
　　IfIamjealousofthetendencytoexpandthetimegiventotheacquisitionofcuriousknowledge，attheexpenseoftheplainold-
　　fashionedbedsideteachings，IonlysharethefeelingwhichSydenhamexpressedtwohundredyearsago，usinganimageIhavealreadyborrowed。“Hewouldbenohonestandsuccessfulpilotwhowastoapplyhimselfwithlessindustrytoavoidrocksandsandsandbringhisvesselsafelyhome，thantosearchintothecausesoftheebbingandflowingofthesea，which，thoughverywellforaphilosopher，isforeigntohimwhosebusinessitistosecuretheship。Soneitherwillaphysician，whoseprovinceitistocurediseases，beabletodoso，thoughhebeapersonofgreatgenius，whobestowslesstimeonthehiddenandintricatemethodofnature，andadaptinghismeansthereto，thanoncuriousandsubtlespeculation。“
　　“MedicineismywifeandScienceismymistress，“saidDr。Rush。I
　　donotthinkthatthebreachoftheseventhcommandmentcanbeshowntohavebeenofadvantagetothelegitimateownerofhisaffections。
　　ReadwhatDr。ElishaBartlettsaysofhimasapractitioner，oraskoneofourownhonoredex-professors，whostudiedunderhim，whetherDr。RushhadeverlearnedthemeaningofthatsayingofLordBacon，thatmanistheministerandinterpreterofNature，orwhetherhedidnotspeakhabituallyofNatureasanintruderinthesickroom，fromwhichhisartwastoexpelherasanincompetentandameddler。
　　Allaman’spowersarenottoomuchforsuchaprofessionasMedicine。“Heisalearnedman，“saidoldParsonEmmonsofFranklin，“whounderstandsonesubject，andheisaverylearnedmanwhounderstandstwosubjects。“Schonbeinsayshehasbeenstudyingoxygenforthirtyyears。Mitscherlichsaidittookfourteenyearstoestablishanewfactinchemistry。AubreysaysofHarvey，thediscovererofthecirculation，that“thoughallhisprofessionwouldallowhimtobeanexcellentanatomist，Ihaveneverheardofanywhoadmiredhistherapeuticway。“Mylearnedandexcellentfriendbeforereferredto，Dr。BrownofEdinburgh，fromwhoseverylivelyandsensibleEssay，“LockeandSydenham，“Ihaveborrowedseveralofmycitations，contrastsSirCharlesBell，thediscoverer，themanofscience，withDr。Abercrombie，themasterinthediagnosisandtreatmentofdisease。ItisthroughoneoftherarestofcombinationsthatwehaveinourFacultyateacheronwhomthescientificmantleofBellhasfallen，andwhoyetstandspreeminentinthepracticaltreatmentoftheclassofdiseaseswhichhisinventiveandardentexperimentalgeniushasillustrated。M。Brown-
　　Sequard’sexampleisas，eloquentashisteachinginproofoftheadvantagesofwelldirectedscientificinvestigation。Butthosewhoemulatehissuccessatonceasadiscovererandapractitionermustbecontentlikehimtolimittheirfieldofpractice。Thehighestgeniuscannotaffordinourtimetoforgettheancientprecept，Divideetimpera。
　　“IsupposeImustgoandearnthisguinea，“saidamedicalmanwhowassentforwhilehewasdissectingananimal。Ishouldnothavecaredtobehispatient。Hisdissectionwoulddomenogood，andhisthoughtswouldbetoomuchuponit。Iwantawholemanformydoctor，notahalfone。Iwouldhavesentforahumblerpractitioner，whowouldhavegivenhimselfentirelytome，andtoldtheother——whowasnolessamanthanJohnHunter——togoonandfinishthedissectionofhistiger。
　　Sydenham’s“ReadDonQuixote“shouldbeaddressednottothestudent，buttotheProfessoroftoday。Aimedathimitmeans，“Donotbetoolearned。
　　Donotthinkyouaregoingtolecturetopickedyoungmenwhoaretrainingthemselvestobescientificdiscoverers。Theyareoffairaveragecapacity，andtheyaregoingtobeworkingdoctors。
　　Theseyoungmenaretohavesomeveryseriousvitalfactstodealwith。Iwillmentionafewofthem。
　　Everyotherresidentadultyoumeetinthesestreetsisorwillbemoreorlesstuberculous。Thisisnotanextravagantestimate，asverynearlyonethirdofthedeathsofadultsinBostonlastyearwerefromphthisis。Iftherelativenumberislessinourothernortherncities，itisprobablyinagreatmeasurebecausetheyaremoreunhealthy；thatis，theyhaveasmuch，ornearlyasmuch，consumption，buttheyhavemorefeversorotherfataldiseases。
　　Theseheavy-eyedmenwiththealcoholizedbrains，thesepallidyouthswiththenicotizedopticgangliaandthinking-marrowsbrownastheirownmeerschaums，ofwhomyoumeettoomany，——willaskallyourwisdomtodealwiththeirpoisonednervesandtheirenfeebledwills。
　　Nearlyseventeenhundredchildrenunderfiveyearsofagediedlastyearinthiscity。Apoorhumanarticle，nodoubt，inmanycases，still，worthanattempttosavethem，especiallywhenweremembertheeffectofDr。Clarke’ssuggestionattheDublinHospital，bywhichsometwenty-fiveorthirtythousandchildren’sliveshaveprobablybeensavedinasinglecity。