Istherenoprogress，then，butdowereturntothesamebeliefsandpracticeswhichourforefathersworeoutandthrewaway？Itrustandbelievethatthereisarealprogress。Wemay，forinstance，returninameasuretotheBrunonianstimulatingsystem，butitmustbeinamodifiedway，forwecannotgobacktothesimpleBrunonianpathology，sincewehavelearnedtoomuchofdiseasedactiontoacceptitsconvenientdualism。Soofotherdoctrines，eachnewAvatarstripsthemofsomeoftheiroldpretensions，untiltheytaketheirfittingplaceatlast，iftheyhaveanytruthinthem，ordisappear，iftheyweremerephantasmsoftheimagination。
　　Inthemeantime，whilemedicaltheoriesarecominginandgoingout，thereisasetofsensiblemenwhoareneverrunawaywithbythem，butpractisetheirartsagaciouslyandfaithfullyinmuchthesamewayfromgenerationtogeneration。FromthetimeofHippocratestothatofourownmedicalpatriarch，therehasbeenanapostolicsuccessionofwiseandgoodpractitioners。IfyouwilllookatthefirstaphorismoftheancientMasteryouwillseethatbeforeallremediesheplacestheproperconductofthepatientandhisattendants，andthefitorderingofalltheconditionssurroundinghim。TheclassofpractitionersIhavereferredtohavealwaysbeenthemostfaithfulinattendingtothesepoints。Nodoubttheyhavesometimesprescribedunwisely，incompliancewiththeprejudicesoftheirtime，buttheyhavegrownwiserastheyhavegrownolder，andlearnedtotrustmoreinnatureandlessintheirplansofinterference。IbelievecommonopinionconfirmsSirJamesClark’sobservationtothiseffect。
　　Theexperienceoftheprofessionmust，Ithink，runparallelwiththatofthewisestofitsindividualmembers。Eachtimeaplanoftreatmentoraparticularremedycomesupfortrial，itissubmittedtoasharperscrutiny。WhenCullenwrotehisMateriaMedica，hehadseriouslytoassailthepracticeofgivingburnttoad，whichwasstillcountenancedbyatleastonemedicalauthorityofnote。Ihavereadrecentlyinsomemedicaljournal，thatanAmericanpractitioner，whosenameisknowntothecountry，isprescribingthehoofofahorseforepilepsy。Itwasdoubtlesssuggestedbythatoldfancyofwearingaportionofelk’shoofhungroundtheneckorinaring，forthisdisease。Butitishardtopersuadereasonablepeopletoswallowtheabominationsofaformerperiod。TheevidencewhichsatisfiedFerneliuswillnotserveoneofourhospitalphysicians。
　　InthiswaythosearticlesoftheMateriaMedicawhichhadnothingbutloathsomenesstorecommendthemhavebeengraduallydropped，andarenotliketoobtainanygeneralfavoragainwithcivilizedcommunities。Thenextculpritstobetriedarethepoisons。Ihaveneverbeenintheleastscepticalastotheutilityofsomeofthem，whenproperlyemployed。ThoughIbelievethatatpresent，takingtheworldatlarge，andleavingoutafewpowerfulagentsofsuchimmensevaluethattheyranknexttofoodinimportance，thepoisonsprescribedfordiseasedomorehurtthangood，Ihavenodoubt，andneverprofessedtohaveany，thattheydomuchgoodinprudentandinstructedhands。ButIamverywillingtoconfessagreatjealousyofmanyagents，andIcouldalmostwishtoseetheMateriaMedicasoclassedastocallsuspicionuponcertainonesamongthem。
　　Thusthealienelements，thosewhichdonotproperlyenterintothecompositionofanylivingtissue，arethemosttobesuspected，——
　　mercury，lead，antimony，silver，andtherest，forthereasonsIhavebeforementioned。Eveniodine，which，asitisfoundincertainplants，seemslessremotefromtheanimaltissues，givesunequivocalproofsfromtimetotimethatitishostiletosomeportionsoftheglandularsystem。
　　Thereis，ofcourse，lessprimafacieobjectiontothoseagentswhichconsistofassimilableelements，suchasarefoundmakingapartofhealthytissues。Thesearedivisibleintothreeclasses，——foods，poisons，andinert，mostlybecauseinsoluble，substances。Thefoodofoneanimalorofonehumanbeingissometimespoisontoanother，andviceversa；inertsubstancesmayactmechanically，soastoproducetheeffectofpoisons；butthisdivisionholdsexactlyenoughforourpurpose。
　　Strictlyspeaking，everypoisonconsistingofassimilableelementsmaybeconsideredasunwholesome，food。Itisrejectedbythestomach，oritproducesdiarrhoea，oritcausesvertigoordisturbanceoftheheart’saction，orsomeothersymptomforwhichthesubjectofitwouldconsultthephysician，ifitcameonfromanyothercausethantakingitunderthenameofmedicine。Yetportionsofthisunwholesomefoodwhichwecallmedicine，wehavereasontobelieve，areassimilated；thus，castor-oilappearstobepartiallydigestedbyinfants，sothattheyrequirelargedosestoaffectthemmedicinally。Eventhatdeadliestofpoisons，hydrocyanicacid，isprobablyassimilated，andhelpstomakelivingtissue，ifitdonotkillthepatient，fortheassimilableelementswhichitcontains，givenintheseparateformsofamygdalinandemulsin，producenodisturbance，unless，asinBernard’sexperiments，theyaresufferedtomeetinthedigestiveorgans。Amedicineconsistingofassimilablesubstancesbeingthensimplyunwholesomefood，weunderstandwhatismeantbythosecumulativeeffectsofsuchremediesoftenobserved，asinthecaseofdigitalisandstrychnia。Theyarepreciselysimilartothecumulativeeffectsofasaltdietinproducingscurvy，orofspurredryeinproducingdrygangrene。Astheeffectsofsuchsubstancesareaviolencetotheorgans，weshouldexercisethesamecautionwithregardtotheirusethatwewouldexerciseaboutanyotherkindofpoisonousfood，——partridgesatcertainseasons，forinstance。Evenwherethesepoisonouskindsoffoodseemtobeuseful，weshouldstillregardthemwithgreatjealousy。Digitalislowersthepulseinfebrileconditions。
　　Veratrumviridedoesthesamething。Howdoweknowthatarapidpulseisnotanormaladjustmentofnaturetotheconditionitaccompanies？Digitalishasgoneoutoffavor；howsurearewethatVeratrumviridewillnotbefoundtodomoreharmthangoodinacaseofinternalinflammation，takingthewholecourseofthediseaseintoconsideration？Thinkofthechangeofopinionwithregardtotheuseofopiumindeliriumtremenswhichyourememberissometimescalleddeliriumvigilans，whereitseemedsoobviouslyindicated，sincethepublicationofDr。Ware’sadmirableessay。Irespecttheevidenceofmycontemporaries，butIcannotforgetthesayingsoftheFatherofmedicine，——Arslonga，judiciumdiffcile。
　　IamnotpresumingtoexpressanopinionconcerningVeratrumviride，whichwaslittleheardofwhenIwasstillpractisingmedicine。Iamonlyappealingtothathighercourtofexperiencewhichsitsinjudgmentonalldecisionsofthelowermedicaltribunals，andwhichrequiresmorethanonegenerationforitsfinalverdict。
　　Oncechangethehabitofmindsolongprevalentamongpractitionersofmedicine；onceletitbeeverywhereunderstoodthatthepresumptionisinfavoroffood，andnotofaliensubstances，ofinnocuous，andnotofunwholesomefood，forthesick；thatthispresumptionrequiresverystrongevidenceineachparticularcasetoovercomeit；butthat，whensuchevidenceisafforded，thealiensubstanceortheunwholesomefoodshouldbegivenboldly，insufficientquantities，inthesamespiritasthatwithwhichthesurgeonliftshisknifeagainstapatient，——thatis，withthesamereluctanceandthesamedetermination，——andIthinkweshallhaveandhearmuchlessofcharlatanisminandoutoftheprofession。Thedisgraceofmedicinehasbeenthatcolossalsystemofself-deception，inobediencetowhichmineshavebeenemptiedoftheircankeringminerals，thevegetablekingdomrobbedofallitsnoxiousgrowths，theentrailsofanimalstaxedfortheirimpurities，thepoison-bagsofreptilesdrainedoftheirvenom，andalltheinconceivableabominationsthusobtainedthrustdownthethroatsofhumanbeingssufferingfromsomefaultoforganization，nourishment，orvitalstimulation。
　　Muchaswehavegained，wehavenotyetthoroughlyshakenoffthenotionthatpoisonisthenaturalfoodofdisease，aswholesomealimentisthesupportofhealth。Cowper’slines，in“TheTask，“
　　showthematter-of-coursepracticeofhistime：
　　“Hedoesnotscornit，whohaslongenduredAfever’sagonies，andfedondrugs。“
　　Dr。KimballofLowell，whohasbeeninthehabitofseeingagreatdealmoreoftyphoidfeverthanmostpractitioners，andwhosesurgicalexploitsshowhimnottobewantinginboldnessorenterprise，cantellyouwhetherhefindsitnecessarytofeedhispatientsondrugsornot。Hisexperienceis，Ibelieve，thatofthemostenlightenedandadvancedportionoftheprofession；yetIthinkthatevenintyphoidfever，andcertainlyinmanyothercomplaints，theeffectsofancienthabitsandprejudicesmaystillbeseeninthepracticeofsomeeducatedphysicians。
　　Toyou，youngmen，itbelongstojudgeallthathasgonebeforeyou。
　　Youcomenearertothegreatfathersofmodernmedicinethansomeofyouimagine。ThreeofmyowninstructorsattendedDr。Rush’sLectures。TheillustriousHallermentionsRush’sinauguralthesisinhis“BibliothecaAnatomica；“andthissameHaller，broughtsoclosetous，tellsusheremembersRuysch，thenanoldman，andusedtocarrylettersbetweenhimandBoerhaave。LookthroughthehistoryofmedicinefromBoerhaavetothispresentday。Youwillseeatoncethatmedicaldoctrineandpracticehaveundergonealongseriesofchanges。Youwillseethatthedoctrineandpracticeofourowntimemustprobablychangeintheirturn，andthat，ifwecantrustatalltotheindicationsoftheircourse，itwillbeinthedirectionofanimprovedhygieneandasimplifiedtreatment。Especiallywilltheoldhabitofviolatingtheinstinctsofthesickgiveplacetoajudiciousstudyofthesesameinstincts。Itwillbefoundthatbodily，likementalinsanity，isbestmanaged，forthemostpart，bynaturalsoothingagencies。Twocenturiesagotherewasaprescriptionforscurvycontaining“stercoristaurinietanserinipar，quantitastriummagnarumnucum，“ofthehell-brothcontainingwhich“guoties-cumquesititoeger，largebibit。“WhenIhaverecalledthehumanecommon-senseofCaptainCookinthematterofpreventingthisdisease；whenIhaveheardmyfriend，Mr。Dana，describingtheaviditywithwhichthescurvy-strickensailorssnuffeduptheearthyfragranceoffreshrawpotatoes，thefoodwhichwastosupplytheelementswantingtotheirspongytissues，Ihaverecognizedthattheperfectionofartisoftenareturntonature，andseeninthissingleinstancethegermofinnumerablebeneficentfuturemedicalreforms。
　　Icannothelpbelievingthatmedicalcurativetreatmentwillbyandbyresolveitselfingreatmeasureintomodificationsofthefood，swallowedandbreathed，andofthenaturalstimuli，andthatlesswillbeexpectedfromspecificsandnoxiousdisturbingagents，eitheralienorassimilable。Thenotedmineral-waterscontainingiron，sulphur，carbonicacid，supplynutritiousorstimulatingmaterialstothebodyasmuchasphosphateoflimeandammoniacalcompoundsdotothecerealplants。Theeffectsofamilkandvegetablediet，ofglutenbreadindiabetes，ofcod-liveroilinphthisis，evenofsuchaudaciousinnovationsasthewater-cureandthegrape-cure，areonlyhintsofwhatwillbeaccomplishedwhenwehavelearnedtodiscoverwhatorganicelementsaredeficientorinexcessinacaseofchronicdisease，andthebestwayofcorrectingtheabnormalcondition，justasanagriculturistascertainsthewantsofhiscropsandmodifiesthecompositionofhissoil。Inacutefebrilediseaseswehavelongagodiscoveredthatfarabovealldrug-medicationistheuseofmildliquiddietintheperiodofexcitement，andofstimulantandnutritiousfoodinthatofexhaustion。Hippocrateshimselfwasasparticularabouthisbarley-ptisanasanyFlorenceNightingaleofourtimecouldbe。
　　Thegenerationtowhichyou，whoarejustenteringtheprofession，belong，willmakeavaststrideforward，asIbelieve，inthedirectionoftreatmentbynaturalratherthanviolentagencies。WhatisitthatmakesthereputationofSydenham，asthechiefofEnglishphysicians？Hisprescriptionsconsistedprincipallyofsimples。Anaperientoranopiate，a“cardiac“oratonic，maybecommonlyfoundinthemidstofasomewhatfantasticmiscellanyofgardenherbs。Itwasnotbyhispharmaceuticprescriptionsthathegainedhisgreatname。Itwasbydaringtoorderfreshairforsmall-poxpatients，andridingonhorsebackforconsumptives，inplaceofthesmotheringsystem，andthenoxiousandoftenloathsomerubbishoftheestablishedschools。OfcourseSydenhamwasmuchabusedbyhiscontemporaries，ashefrequentlytakesoccasiontoremindhisreader。
　　“Imustneedsconclude，“hesays，“eitherthatIamvoidofmerit，orthatthecandidandingenuouspartofmankind，whoareformedwithsoexcellentatemperofmindastobenostrangerstogratitude，makeaverysmallpartofthewhole。“Ifinthefearlesspursuitoftruthyoushouldfindtheworldasungraciousinthenineteenthcenturyashefounditintheseventeenth，youmaylearnalessonofself-
　　reliancefromanotherutteranceofthesameillustriousphysician：
　　“’Tisnoneofmybusinesstoinquirewhatotherpersonsthink，buttoestablishmyownobservations；inordertowhich，Iasknofavorofthereaderbuttoperusemywritingswithtemper。“
　　Thephysicianhaslearnedagreatdealfromthesurgeon，whoisnaturallyinadvanceofhim，becausehehasabetteropportunityofseeingtheeffectsofhisremedies。LetmeshortenoneofAmbroisePare’sstoriesforyou。TherehadbeenagreatvictoryatthepassofSusa，andtheywereridingintothecity。Thewoundedcriedoutasthehorsestrampledthemundertheirhoofs，whichcausedgoodAmbroisegreatpity，andmadehimwishhimselfbackinParis。Goingintoastablehesawfourdeadsoldiers，andthreedesperatelywounded，placedwiththeirbacksagainstthewall。Anoldcampaignercameup——“Canthesefellowsgetwell？“hesaid。“No！“answeredthesurgeon。Thereupon，theoldsoldierwalkeduptothemandcutalltheirthroats，sweetly，andwithoutwrathdoulcementetsanscholere。Ambroisetoldhimhewasabadmantodosuchathing。
　　“IhopetoGod；“hesaid，“somebodywilldoasmuchformeifIevergetintosuchascrape“accoustredetellefacon。“Iwasnotmuchsaltedinthosedays“biendouxdesel，saysAmbroise，“andlittleacquaintedwiththetreatmentofwounds。“However，ashetellsus，heproceededtoapplyboilingoilofSambucelderaftertheapprovedfashionofthetime，——withwhattorturetothepatientmaybeguessed。Atlasthispreciousoilgaveout，andheusedinsteadaninsignificantmixtureofhisowncontrivance。Hecouldnotsleepthatnightforfearhispatientswhohadnotbeenscaldedwiththeboilingoilwouldbepoisonedbythegunpowderconveyedintotheirwoundsbytheballs。Tohissurprise，hefoundthemmuchbetterthantheothersthenextmorning，andresolvedneveragaintoburnhispatientswithhotoilforgun-shotwounds。