[NoteB。]
Letmeillustratethispropositionbeforeyoudecideuponit。Ifitwereknownthataprize-fighterweretohaveadrasticpurgativeadministeredtwoorthreedaysbeforeacontest，oralargeblisterappliedtohisback，noonewillquestionthatitwouldaffectthebettingonhissideunfavorably；wewillsaytotheamountoffivepercent。Nowthedrainupontheresourcesofthesystemproducedinsuchacasemustbeatitsminimum，forthesubjectisapowerfulman，intheprimeoflife，andinadmirablecondition。Ifthedrugortheblistertakesfivepercent。fromhisforceofresistance，itwilltakeatleastaslargeafractionfromanyinvalid。Butthisinvalidhastofightachampionwhostrikeshardbutcannotbehitinreturn，whowillpresshimsharplyforbreath，butwillneverpanthimselfwhilethewindcanwhistlethroughhisfleshlessribs。Thesufferingcombatantisliabletowantallhisstamina，andfivepercent。maylosehimthebattle。
Allnoxiousagents，allapplianceswhicharenotnaturalfoodorstimuli，allmedicinesproper，costapatient，ontheaverage，fivepercent。ofhisvitalforce，letussay。Twentytimesasmuchwasteofforceproducedbyanyofthem，thatis，wouldexactlykillhim，nothinglessthankillhim，andnothingmore。Ifthis，orsomethinglikethis，istrue，thenallthesemedicationsare，primafacie，injurious。
InthegameofLife-or-Death，RougeetNoir，asplayedbetweentheDoctorandtheSexton，thisfivepercent。，thiscertainsmallinjuryenteringintothechancesisclearlythesexton’sperquisiteforkeepingthegreentable，overwhichthegameisplayed，andwherehehoardsuphisgains。Supposeablistertodiminishaman’spain，effusionordyspnoeatothesavingoftwentypercent。invitalforce；hisprofitfromitisfifteen，inthatcase，foritalwayshurtshimfivetobeginwith，accordingtoourpreviousassumption。
Presumptionsareofvastimportanceinmedicine，asinlaw。Amanispresumedinnocentuntilheisprovedguilty。Amedicine——thatis，anoxiousagent，likeablister，aseton，anemetic，oracathartic——