VIII。　　Many　series　of　cases；　answering　to　these　conditions；　are　given　in　this　Essay；　and　many　others　will　be　referred　to　which　have　occurred　since　it　was　written。
  IX。　　The　alleged　results　of　observation　may　be　set　aside；　first；　because　the　so…called　facts　are　in　their　own　nature　equivocal；　secondly；　because　they　stand　on　insufficient　authority；　thirdly；　because　they　are　not　sufficiently　numerous。　　But；　in　this　case；　the　disease　is　one　of　striking　and　well…marked　character；　the　witnesses　are　experts；　interested　in　denying　and　disbelieving　the　facts；　the　number　of　consecutive　cases　in　many　instances　frightful；　and　the　number　of　series　of　cases　such　that　I　have　no　room　for　many　of　them　except　by　mere　reference。
  X。　　These　results　of　observation；　being　admitted；　may；　we　will　suppose；　be　interpreted　in　different　methods。　　Thus　the　coincidences　may　be　considered　the　effect　of　chance。　　I　have　had　the　chances　calculated　by　a　competent　person；　that　a　given　practitioner；　A。；　shall　have　sixteen　fatal　cases　in　a　month；　on　the　following　data：　A。　to　average　attendance　upon　two　hundred　and　fifty　births　in　a　year；　three　deaths　in　one　thousand　births　to　be　assumed　as　the　average　from　puerperal　fever；　no　epidemic　to　be　at　the　time　prevailing。　　It　follows；　from　the　answer　given　me；　that　if　we　suppose　every　one　of　the　five　hundred　thousand　annual　births　of　England　to　have　been　recorded　during　the　last　half…century；　there　would　not　be　one　chance　in　a　million　million　million　millions　that　one　such　series　should　be　noted。　　No　possible　fractional　error　in　this　calculation　can　render　the　chance　a　working　probability。　　Applied　to　dozens　of　series　of　various　lengths；　it　is　obviously　an　absurdity。　　Chance；　therefore；　is　out　of　the　question　as　an　explanation　of　the　admitted　coincidences。
  XI。　　There　is；　therefore；　some　relation　of　cause　and　effect　between　the　physician's　presence　and　the　patient's　disease。
  XII。　　Until　it　is　proved　to　what　removable　condition　attaching　to　the　attendant　the　disease　is　owing；　he　is　bound　to　stay　away　from　his　patients　so　soon　as　he　finds　himself　singled　out　to　be　tracked　by　the　disease。　　How　long；　and　with　what　other　precautions；　I　have　suggested；　without　dictating；　at　the　close　of　my　Essay。　　If　the　physician　does　not　at　once　act　on　any　reasonable　suspicion　of　his　being　the　medium　of　transfer；　the　families　where　he　is　engaged；　if　they　are　allowed　to　know　the　facts；　should　decline　his　services　for　the　time。　　His　feelings　on　the　occasion；　however　interesting　to　himself；　should　not　be　even　named　in　this　connection。　　A　physician　who　talks　about　ceremony　and　gratitude；　and　services　rendered；　and　the　treatment　he　got；　surely　forgets　himself；　it　is　impossible　that　he　should　seriously　think　of　these　small　matters　where　there　is　even　a　question　whether　he　may　not　carry　disease；　and　death；　and　bereavement　into　any　one　of　〃his　families；〃　as　they　are　sometimes　called。
  I　will　now　point　out　to　the　young　student　the　mode　in　which　he　may　relieve　his　mind　of　any　confusion；　or　possibly；　if　very　young；　any　doubt；　which　the　perusal　of　Dr。　Meigs's　Sixth　Letter　may　have　raised　in　his　mind。
  The　most　prominent　ideas　of　the　Letter　are；　first；　that　the　transmissible　nature　of　puerperal　fever　appears　improbable；　and；　secondly；　that　it　would　be　very　inconvenient　to　the　writer。　Dr。　Woodville；　Physician　to　the　Small…Pox　and　Inoculation　Hospital　in　London；　found　it　improbable；　and　exceedingly　inconvenient　to　himself；　that　cow　pox　should　prevent　small…pox；　but　Dr。　Jenner　took　the　liberty　to　prove　the　fact；　notwithstanding。
  I　will　first　call　the　young　student's　attention　to　the　show　of　negative　facts　（exposure　without　subsequent　disease）；　of　which　much　seems　to　be　thought。　　And　I　may　at　the　same　time　refer　him　to　Dr。　Hodge's　Lecture；　where　he　will　find　the　same　kind　of　facts　and　reasoning。　　Let　him　now　take　up　Watson's　Lectures；　the　good　sense　and　spirit　of　which　have　made　his　book　a　universal　favorite；　and　open　to　the　chapter　on　Continued　Fever。　　He　will　find　a　paragraph　containing　the　following　sentence：　〃A　man　might　say；　'I　was　in　the　battle　of　Waterloo；　and　saw　many　men　around　me　fall　down　and　die；　and　it　was　said　that　they　were　struck　down　by　musket…balls；　but　I　know　better　than　that；　for　I　was　there　all　the　time；　and　so　were　many　of　my　friends；　and　we　were　never　hit　by　any　musket…balls。　　Musket…balls；　therefore；　could　not　have　been　the　cause　of　the　deaths　we　witnessed。'　And　if；　like　contagion；　they　were　not　palpable　to　the　senses；　such　a　person　might　go　on　to　affirm　that　no　proof　existed　of　there　being　any　such　thing　as　musket…balls。〃　　Now　let　the　student　turn　back　to　the　chapter　on　Hydrophobia　in　the　same　volume。　　He　will　find　that　John　Hunter　knew　a　case　in　which；　of　twenty…one　persons　bitten；　only　one　died　of　the　disease。　　He　will　find　that　one　dog　at　Charenton　was　bitten　at　different　times　by　thirty　different　mad　dogs；　and　outlived　it　all。　　Is　there　no　such　thing；　then；　as　hydrophobia？　　Would　one　take　no　especial　precautions　if　his　wife；　about　to　become　a　mother；　had　been　bitten　by　a　rabid　animal；　because　so　many　escape？　　Or　let　him　look　at　〃Underwood　on　Diseases　of　Children；〃＇Philadelphia；　1842；　p。　　244；　note。＇　and　he　will　find　the　case　of　a　young　woman　who　was　inoculated　eight　times　in　thirty　days；　at　the　same　time　attending　several　children　with　smallpox；　and　yet　was　not　infected。　　But　seven　weeks　afterwards　she　took　the　disease　and　died。
  It　would　seem　as　if　the　force　of　this　argument　could　hardly　fail　to　be　seen；　if　it　were　granted　that　every　one　of　these　series　of　cases　were　so　reported　as　to　prove　that　there　could　have　been　no　transfer　of　disease。　　There　is　not　one　of　them　so　reported；　in　the　Lecture　or　the　Letter；　as　to　prove　that　the　disease　may　not　have　been　carried　by　the　practitioner。　　I　strongly　suspect　that　it　was　so　carried　in　some　of　these　cases；　but　from　the　character　of　the　very　imperfect　evidence　the　question　can　never　be　settled　without　further　disclosures。
  Although　the　Letter　is；　as　I　have　implied；　principally　taken　up　with　secondary　and　collateral　questions；　and　might　therefore　be　set　aside　as　in　the　main　irrelevant；　I　am　willing；　for　the　student's　sake；　to　touch　some　of　these　questions　briefly；　as　an　illustration　of　its　logical　character。
  The　first　thing　to　be　done；　as　I　thought　when　I　wrote　my　Essay；　was　to　throw　out　all　discussions　of　the　word　contagion；　and　this　I　did　effectually　by　the　careful　wording　of　my　statement　of　the　subject　to　be　discussed。　　My　object　was　not　to　settle　the　etymology　or　definition　of　a　word；　but　to　show　that　women　had　often　died　in　childbed；　poisoned　in　some　way　by　their　medical　attendants。　　On　the　other　point；　I；　at　least；　have　no　controversy　with　anybody；　and　I　think　the　student　will　do　well　to　avoid　it　in　this　connection。　　If　I　must　define　my　position；　however；　as　well　as　the　term　in　question；　I　am　contented　with　Worcester's　definition；　provided　always　this　avowal　do　not　open　another　side　controversy　on　the　merits　of　his　Dictionary；　which　Dr。　Meigs　has　not　cited；　as　compared　with　Webster's；　which　he　has。
  I　cannot　see　the　propriety　of　insisting　that　all　the　laws　of　the　eruptive　fevers　must　necessarily　hold　true　of　this　peculiar　disease　of　puerperal　women。　　If　there　were　any　such　propriety；　the　laws　of　the　eruptive　fevers　must　at　least　be　stated　correctly。　　It　is　not　true；　for　instance；　as　Dr。　Meigs　states；　that　contagion　is　〃no　respecter　of　persons；〃　that　〃it　attacks　all　individuals　alike。〃　　To　give　one　example：　Dr。　Gregory；　of　the　Small…Pox　Hospital；　who　ought　to　know；　says　that　persons　pass　through　life　apparently　insensible　to　or　unsusceptible　of　the　small…pox　virus；　and　that　the　same　persons　do　not　take　the　vaccine　disease。
  As　to　the　short　time　of　incubation；　of　which　so　much　is　made；　we　have　no　right　to　decide　beforehand　whether　it　shall　be　long　or　short；　in　the　cases　we　are　considering。　　A　dissection　wound　may　produce　symptoms　of　poisoning　in　six　hours；　the　bite　of　a　rabid　animal　may　take　as　many　months。
  After　the　student　has　read　the　case　in　Dr。　Meigs's　136th　paragraph；　and　the　following　one；　in　which　he　exclaims　against　the　idea　of　contagion；　because　the　patient；　delivered　on　the　26th　of　December；　was　attacked　in　twenty…four　hours；　and　died　on　the　third　day；　let　him　read　what　happened　at　the　〃Black　Assizes〃　of　1577　and　1750。　　In　the　first　case；　six　hundred　persons　sickened　the　same　night　of　the　exposure；　and　three　hundred　more　in　three　days。　＇Elliotson's　Practice；　p。　　298。＇　　Of　those　attacked　in　the　latter　year；　the　exposure　being　on　the　11th　of　May；　Alderman　Lambert　died　on　the　13th；　Under…Sheriff　Cox　on　the　14th；　and　many　of　note　before　the　20th。　　But　these　are　old　stories。　　Let　the　student　listen　then　to　Dr。　Gerhard；　whose　reputation　as　a　cautious　observer　he　may　be　supposed　to　know。　　〃The　nurse　was　shaving　a　man；　who　died　in　a　few　hours　after　his　entrance；　he　inhaled　his　breath；　which　had　a　nauseous　taste；　and　in　an　hour　afterwards　was　taken　with　nausea；　cephalalgia；　and　singing　of　the　ears。　　From　that　moment　the　attack　began；　and　assumed　a　severe　character。　　The　assistant　was　supporting　another　patient；　who　died　soon　afterwards；　he　felt　the　pungent　heat　upon　his　skin；　and　was　taken　immediately　with　the　symptoms　of　typhus。〃＇Am。　　Jour。　　Med。　Sciences；　Feb。