Intheearliestandembryonicstageofprofessionaldevelopment，anyviolentimpressionontheinstructor’smindisapttobefollowedbysomelastingeffectonthatofthepupil。Nomother’smarkismorepermanentthanthementalnaeviandmoles，andexcrescences，andmutilations，thatstudentscarrywiththemoutofthelecture-room，ifoncetheteemingintellectwhichnourishestheirshasbeenscaredfromitsproprietybyanymisshapenfantasy。Evenanimpatientorpetulantexpression，whichtoaphilosopherwouldbeamereindexofthelowstateofamiabilityofthespeakeratthemomentofitsutterance，maypassintotheyoungmindasanelementofitsfutureconstitution，toinjureitstemperorcorruptitsjudgment。Itisaduty，therefore，whichweowetothisyoungerclassofstudents，toclearanyimportanttruthwhichmayhavebeenrenderedquestionableintheirmindsbysuchlanguage，oranytruth-telleragainstwhomtheymayhavebeenprejudicedbyhastyepithets，fromtheimpressionssuchwordshaveleft。Untilthisisdone，theyarenotreadyforthequestion，wherethereisaquestion，forthemtodecide。Evenifweourselvesarethesubjectsoftheprejudice，thereseemstobenoimproprietyinshowingthatthisprejudiceislocalorpersonal，andnotanacknowledgedconvictionwiththepublicatlarge。Itmaybenecessarytobreakthroughourusualhabitsofreservetodothis，butthisisthefaultofthepositioninwhichothershaveplacedus。
　　Twowidely-knownandhighly-esteemedpractitioners，ProfessorsintwoofthelargestMedicalSchoolsoftheUnion，teachingthebranchofartwhichincludestheDiseasesofWomen，andthereforespeakingwithauthority；addressingintheirlecturesandprintedpublicationslargenumbersofyoungmen，manyoftheminthetenderestimmaturityofknowledge，haverecentlytakengroundinaformalwayagainstthedoctrinemaintainedinthispaper：
　　OntheNon-ContagiousCharacterofPuerperalFever：AnIntroductoryLecture。ByHughL。Hodge，M。D。，ProfessorofObstetricsintheUniversityofPennsylvania。DeliveredMonday，October11，1852。
　　Philadelphia，1852。
　　OntheNature，Signs，andTreatmentofChildbedFevers：inaSeriesofLettersaddressedtotheStudentsofhisClass。ByCharlesD。
　　Meigs，M。D。，ProfessorofMidwiferyandtheDiseasesofWomenandChildreninJeffersonMedicalCollege，Philadelphia，etc。，etc。
　　Philadelphia，1854。LetterVI。
　　Thefirstofthetwopublications，Dr。Hodge’sLecture，whileitstheoreticalconsiderationsandnegativeexperiencesdonotseemtometorequireanyfurthernoticethansuchaslayreadyfortheminmyEssaywrittenlongbefore，is，Iampleasedtosay，unobjectionableintoneandlanguage，andmaybereadwithoutoffence。
　　ThiscanhardlybesaidofthechapterofDr。Meigs’svolumewhichtreatsofContagioninChildbedFever。Thereareexpressionsusedinitwhichmightwellputastoptoallscientificdiscussions，weretheytoformthecurrentcoininourexchangeofopinions。Ileavethe“veryyounggentlemen，“whosecarefulexpositionsoftheresultsofpracticeinmorethansixthousandcasesarecharacterizedas“thejejuneandfizenlessdreamingsofsophomorewriters，“tothesympathiesofthose“dearyoungfriends，“and“dearyounggentlemen，“
　　whowilljudgehowmuchtovaluetheirinstructor’scounseltothinkforthemselves，knowingwhattheyaretoexpectiftheyhappennottothinkashedoes。
　　OneunpalatableexpressionIsupposethelawsofconstructionobligemetoappropriatetomyself，asmyrewardforacertainamountoflaborbestowedontheinvestigationofaveryimportantquestionofevidence，andastatementofmyownpracticalconclusions。Itakenooffence，andattemptnoretort。Nomanmakesaquarrelwithmeoverthecounterpanethatcoversamother，withhernew-borninfantatherbreast。Thereisnoepithetinthevocabularyofslightandsarcasmthatcanreachmypersonalsensibilitiesinsuchacontroversy。Onlyjustsofarasadisrespectfulphrasemayturnthestudentasidefromtheexaminationoftheevidence，bydiscreditingordishonoringthewitness，doesitcallforanywordofnotice。
　　IappealfromthedisparaginglanguagebywhichtheProfessorintheJeffersonSchoolofPhiladelphiaworlddisposeofmyclaimstobelistenedto。Iappeal，nottothevoteoftheSocietyforMedicalImprovement，althoughthiswasanunusualevidenceofinterestinthepaperinquestion，foritwasavotepassedamongmyowntownsmen；
　　nortotheopinionofanyAmerican，fornoneknowbetterthantheProfessorsinthegreatSchoolsofPhiladelphiahowcheaplythepraiseofnativecontemporarycriticismisobtained。IappealtotherecordedopinionsofthosewhomIdonotknow，andwhodonotknowme，norcareforme，exceptforthetruththatImayhaveuttered；toCopland，inhis“MedicalDictionary，“whohasspokenofmyEssayinphrasestowhichthepamphletsofAmerican“scribblers“areseldomusedfromEuropeanauthorities；toRamsbotham，whosecompendiouseulogyisallthatself-lovecouldask；tothe“FifthAnnualReport“
　　oftheRegistrar-GeneralofEngland，inwhichthesecond-handabstractofmyEssayfigureslargely，andnotwithoutfavorablecomment，inanimportantappendedpaper。Thesetestimonies，halfforgottenuntilthiscircumstancerecalledthem，aredraggedintothelight，notinaparoxysmofvanity，buttoshowthattheremaybefoodforthoughtinthesmallpamphletwhichthePhiladelphiaTeachertreatssolightly。Theywereatleastunsoughtfor，andwouldneverhavebeenproclaimedbutforthesakeofsecuringtheprivilegeofadecentandunprejudicedhearing。
　　Iwilltakeitforgrantedthattheyhavesofarcounterpoisedthedepreciatinglanguageofmyfellow-countrymanandfellow-teacherastogainmeareaderhereandthereamongtheyouthfulclassofstudentsIamnowaddressing。ItisonlyfortheirsakethatIthinkitnecessarytoanalyze，orexplain，orillustrate，orcorroborateanyportionofthefollowingEssay。ButIknowthatnothingcanbemadetooplainforbeginners；andasIdonotexpectthepractitioner，oreventhemorematurestudent，totakethetroubletofollowmethroughanIntroductionwhichIconsiderwhollyunnecessaryandsuperfluousforthem，Ishallnothesitatetostooptothemostelementarysimplicityforthebenefitoftheyoungerstudent。Idothismorewillinglybecauseitaffordsagoodopportunity，asitseemstome，ofexercisingtheuntrainedmindinthatmedicallogicwhichdoesnotseemtohavebeeneithertaughtorpractisedinourschoolsoflate，totheextentthatmightbedesired。
　　Iwillnowexhibit，inaseriesofpropositionsreducedtotheirsimplestexpression，thesameessentialstatementsandconclusionsasarecontainedintheEssay，withsuchcommentariesandexplanationsasmaybeprofitabletotheinexperiencedclassofreadersaddressed。
　　I。Ithasbeenlongbelieved，bymanycompetentobservers，thatPuerperalFeversocalledissometimescarriedfrompatienttopatientbymedicalassistants。
　　II。TheexpressobjectofthisEssayistoprovethatitissocarried。
　　III。Inordertoprovethispoint，itisnotnecessarytoconsultanymedicaltheoristastowhetherornotitisconsistentwithhispreconceivednotionsthatsuchamodeoftransfershouldexist。
　　IV。Ifthemedicaltheoristinsistsonbeingconsulted，andweseefittoindulgehim，hecannotbeallowedtoassumethattheallegedlawsofcontagion，deducedfromobservationinotherdiseases，shallbecitedtodisprovetheallegedlawsdeducedfromobservationinthis。Sciencewouldnevermakeprogressundersuchconditions。
　　Neitherthelongincubationofhydrophobia，northeprotectingpowerofvaccination，wouldeverhavebeenadmitted，iftheresultsofobservationintheseaffectionshadbeenrejectedascontradictorytothepreviouslyascertainedlawsofcontagion。
　　V。Thediseaseinquestionisnotacommonone；producing，ontheaverage，aboutthreedeathsinathousandbirths，accordingtotheEnglishRegistrationreturnswhichIhaveexamined。
　　VI。Whenanunusuallylargenumberofcasesofthisdiseaseoccuraboutthesametime，itisinferred，therefore，thatthereexistssomespecialcauseforthisincreasedfrequency。Ifthediseaseprevailsextensivelyoverawideregionofcountry，itisattributedwithoutdisputetoanepidemicinfluence。Ifitprevailsinasinglelocality，asinahospital，andnotelsewhere，thisisconsideredproofthatsomelocalcauseisthereactiveinitsproduction。
　　VII。Whenalargenumberofcasesofthisdiseaseoccurinrapidsuccession，inoneindividual’sordinarypractice，andfewornoneelsewhere，thesecasesappearinginscatteredlocalities，inpatientsofthesameaverageconditionasthosewhoescapeunderthecareofothers，thereisthesamereasonforconnectingthecauseofthediseasewiththepersoninthisinstance，aswiththeplaceinthatlastmentioned。
　　VIII。Manyseriesofcases，answeringtotheseconditions，aregiveninthisEssay，andmanyotherswillbereferredtowhichhaveoccurredsinceitwaswritten。
　　IX。Theallegedresultsofobservationmaybesetaside；first，becausetheso-calledfactsareintheirownnatureequivocal；
　　secondly，becausetheystandoninsufficientauthority；thirdly，becausetheyarenotsufficientlynumerous。But，inthiscase，thediseaseisoneofstrikingandwell-markedcharacter；thewitnessesareexperts，interestedindenyinganddisbelievingthefacts；thenumberofconsecutivecasesinmanyinstancesfrightful，andthenumberofseriesofcasessuchthatIhavenoroomformanyofthemexceptbymerereference。
　　X。Theseresultsofobservation，beingadmitted，may，wewillsuppose，beinterpretedindifferentmethods。Thusthecoincidencesmaybeconsideredtheeffectofchance。Ihavehadthechancescalculatedbyacompetentperson，thatagivenpractitioner，A。，shallhavesixteenfatalcasesinamonth，onthefollowingdata：
　　A。toaverageattendanceupontwohundredandfiftybirthsinayear；
　　threedeathsinonethousandbirthstobeassumedastheaveragefrompuerperalfever；noepidemictobeatthetimeprevailing。Itfollows，fromtheanswergivenme，thatifwesupposeeveryoneofthefivehundredthousandannualbirthsofEnglandtohavebeenrecordedduringthelasthalf-century，therewouldnotbeonechanceinamillionmillionmillionmillionsthatonesuchseriesshouldbenoted。Nopossiblefractionalerrorinthiscalculationcanrenderthechanceaworkingprobability。Appliedtodozensofseriesofvariouslengths，itisobviouslyanabsurdity。Chance，therefore，isoutofthequestionasanexplanationoftheadmittedcoincidences。
　　XI。Thereis，therefore，somerelationofcauseandeffectbetweenthephysician’spresenceandthepatient’sdisease。
　　XII。Untilitisprovedtowhatremovableconditionattachingtotheattendantthediseaseisowing，heisboundtostayawayfromhispatientssosoonashefindshimselfsingledouttobetrackedbythedisease。Howlong，andwithwhatotherprecautions，Ihavesuggested，withoutdictating，atthecloseofmyEssay。Ifthephysiciandoesnotatonceactonanyreasonablesuspicionofhisbeingthemediumoftransfer，thefamilieswhereheisengaged，iftheyareallowedtoknowthefacts，shoulddeclinehisservicesforthetime。Hisfeelingsontheoccasion，howeverinterestingtohimself，shouldnotbeevennamedinthisconnection。Aphysicianwhotalksaboutceremonyandgratitude，andservicesrendered，andthetreatmenthegot，surelyforgetshimself；itisimpossiblethatheshouldseriouslythinkofthesesmallmatterswherethereisevenaquestionwhetherhemaynotcarrydisease，anddeath，andbereavementintoanyoneof“hisfamilies，“astheyaresometimescalled。
　　Iwillnowpointouttotheyoungstudentthemodeinwhichhemayrelievehismindofanyconfusion，orpossibly，ifveryyoung，anydoubt，whichtheperusalofDr。Meigs’sSixthLettermayhaveraisedinhismind。
　　ThemostprominentideasoftheLetterare，first，thatthetransmissiblenatureofpuerperalfeverappearsimprobable，and，secondly，thatitwouldbeveryinconvenienttothewriter。
　　Dr。Woodville，PhysiciantotheSmall-PoxandInoculationHospitalinLondon，founditimprobable，andexceedinglyinconvenienttohimself，thatcowpoxshouldpreventsmall-pox；butDr。Jennertookthelibertytoprovethefact，notwithstanding。
　　Iwillfirstcalltheyoungstudent’sattentiontotheshowofnegativefactsexposurewithoutsubsequentdisease，ofwhichmuchseemstobethought。AndImayatthesametimereferhimtoDr。
　　Hodge’sLecture，wherehewillfindthesamekindoffactsandreasoning。LethimnowtakeupWatson’sLectures，thegoodsenseandspiritofwhichhavemadehisbookauniversalfavorite，andopentothechapteronContinuedFever。Hewillfindaparagraphcontainingthefollowingsentence：“Amanmightsay，’IwasinthebattleofWaterloo，andsawmanymenaroundmefalldownanddie，anditwassaidthattheywerestruckdownbymusket-balls；butIknowbetterthanthat，forIwasthereallthetime，andsoweremanyofmyfriends，andwewereneverhitbyanymusket-balls。Musket-balls，therefore，couldnothavebeenthecauseofthedeathswewitnessed。’