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。