3。Itisnotpretendedthatthecontagionofpuerperalfevermustalwaysbefollowedbythedisease。Itistrueofallcontagiousdiseases，thattheyfrequentlysparethosewhoappeartobefullysubmittedtotheirinfluence。Eventhevaccinevirus，freshfromthesubject，failseverydaytoproduceitslegitimateeffect，thougheveryprecautionistakentoinsureitsaction。Thisisstillmoreremarkablythecasewithscarletfeverandsomeotherdiseases。
4。Itisgrantedthatthediseasemaybeproducedandvariouslymodifiedbymanycausesbesidescontagion，andmoreespeciallybyepidemicandendemicinfluences。Butthisisnotpeculiartothediseaseinquestion。Thereisnodoubtthatsmall-poxispropagatedtoagreatextentbycontagion，yetitgoesthroughthesameperiodsofperiodicalincreaseanddiminutionwhichhavebeenremarkedinpuerperalfever。Ifthequestionisaskedhowwearetoreconcilethegreatvariationsinthemortalityofpuerperalfeverindifferentseasonsandplaceswiththesuppositionofcontagion，IwillansweritbyanotherquestionfromMr。Farr’slettertotheRegistrar-
General。Hemakesthestatementthat“fivedieweeklyofsmall-poxinthemetropoliswhenthediseaseisnotepidemic，“——andadds，“Theproblemforsolutionis，——Whydothefivedeathsbecome10，15，20，31，58，88，weekly，andthenprogressivelyfallthroughthesamemeasuredsteps？“
5。Itakeitforgranted，thatifitcanbeshownthatgreatnumbersofliveshavebeenandaresacrificedtoignoranceorblindnessonthispoint，noothererrorofwhichphysiciansornursesmaybeoccasionallysuspectedwillbeallegedinpalliationofthis；butthatwheneverandwherevertheycanbeshowntocarrydiseaseanddeathinsteadofhealthandsafety，thecommoninstinctsofhumanitywillsilenceeveryattempttoexplainawaytheirresponsibility。
ThetreatiseofDr。GordonofAberdeenwaspublishedintheyear1795，beingamongtheearlierspecialworksuponthedisease。Apartofhistestimonyhasbeenoccasionallycopiedintootherworks，buthisexpressionsaresoclear，hisexperienceisgivenwithsuchmanlydistinctnessanddisinterestedhonesty，thatitmaybequotedasamodelwhichmighthavebeenoftenfollowedwithadvantage。