Earlylifeandeducation[edit] 　　Snowwasborn15March1813inYork,England.HewasthefirstofninechildrenborntoWilliamandFrancesSnowintheirNorthStreethome.HisneighbourhoodwasoneofthepoorestinthecityandwasalwaysindangeroffloodingbecauseofitsproximitytotheRiverOuse.Hisfatherworkedinthelocalcoalyards,whichwereconstantlyreplenishedfromtheYorkshirecoalfieldsthroughthebargesontheOuse.SnowwasbaptisedattheAnglicanchurchofAllSaints,NorthStreet. 　　AllSaints,NorthStreet 　　SnowstudiedinYorkuntiltheageof14,whenhewasapprenticedtoWilliamHardcastle,asurgeoninNewcastleuponTyne.Itwasthere,in1831,thathefirstencounteredcholera,whichenteredNewcastleviatheseaportofSunderlandanddecimatedthetown.[1]Between1833and1836Snowworkedasanassistanttoacollierysurgeon,firstinBurnopfield,CountyDurham,andtheninPateleyBridge,NorthYorkshire.InOctober1836heenrolledattheHunterianschoolofmedicineonGreatWindmillStreet,London.[2] 　　Career[edit] 　　In1837SnowbeganworkingattheWestminsterHospital.AdmittedasamemberoftheRoyalCollegeofSurgeonsofEnglandon2May1838,hegraduatedfromtheUniversityofLondoninDecember1844andwasadmittedtotheRoyalCollegeofPhysiciansin1850.In1850hewasalsooneofthefoundingmembersoftheEpidemiologicalSocietyofLondon,formedinresponsetothecholeraoutbreakof1849.[3] 　　In1857Snowmadeanearlyandoftenoverlooked[4]contributiontoepidemiologyinapamphlet,Ontheadulterationofbreadasacauseofrickets.[5] 　　Anaesthesia[edit] 　　Snowwasoneofthefirstphysicianstostudyandcalculatedosagesfortheuseofetherandchloroformassurgicalanaesthetics,allowingpatientstoundergosurgicalandobstetricprocedureswithoutthedistressandpaintheywouldotherwiseexperience.Hedesignedtheapparatustosafelyadministerethertothepatientsandalsodesignedamasktoadministerchloroform.[6]HepersonallyadministeredchloroformtoQueenVictoriawhenshegavebirthtothelasttwoofherninechildren,Leopoldin1853andBeatricein1857,[7]leadingtowiderpublicacceptanceofobstetricanaesthesia.Snowpublishedanarticleonetherin1847entitledOntheInhalationoftheVaporofEther.AlongerversionentitledOnChloroformandOtherAnaestheticsandTheirActionandAdministrationwaspublishedposthumouslyin1858. 　　Cholera[edit] 　　Mainarticle:1854BroadStreetcholeraoutbreak 　　OriginalmapbyJohnSnowshowingtheclustersofcholeracasesintheLondonepidemicof1854,drawnandlithographedbyCharlesCheffins. 　　Snowwasascepticofthethen-dominantmiasmatheorythatstatedthatdiseasessuchascholeraandbubonicplaguewerecausedbypollutionoranoxiousformof"badair".Thegermtheoryofdiseasehadnotyetbeendeveloped,soSnowdidnotunderstandthemechanismbywhichthediseasewastransmitted.Hisobservationoftheevidenceledhimtodiscountthetheoryoffoulair.Hefirstpublicisedhistheoryinan1849essay,OntheModeofCommunicationofCholera,followedbyamoredetailedtreatisein1855incorporatingtheresultsofhisinvestigationoftheroleofthewatersupplyintheSohoepidemicof1854.[8] 　　Bytalkingtolocalresidents(withthehelpofReverendHenryWhitehead),heidentifiedthesourceoftheoutbreakasthepublicwaterpu