the origination of living beings-第5章

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allow　of　the　growth　of　those　it　received　from　the　air；　which　was　about
forty…eight　hours。　　The　result　of　M。　Pasteur's　experiments　proved；
therefore；　in　the　most　conclusive　manner；　that　all　the　appearances　of
spontaneous　generation　arose　from　nothing　more　than　the　deposition　of
the　germs　of　organisms　which　were　constantly　floating　in　the　air。

To　this　conclusion；　however；　the　objection　was　made；　that　if　that　were
the　cause；　then　the　air　would　contain　such　an　enormous　number　of　these
germs；　that　it　would　be　a　continual　fog。　　But　M。　Pasteur　replied　that
they　are　not　there　in　anything　like　the　number　we　might　suppose；　and
that　an　exaggerated　view　has　been　held　on　that　subject；　he　showed　that
the　chances　of　animal　or　vegetable　life　appearing　in　infusions；　depend
entirely　on　the　conditions　under　which　they　are　exposed。　　If　they　are
exposed　to　the　ordinary　atmosphere　around　us；　why；　of　course；　you　may
have　organisms　appearing　early。　　But；　on　the　other　hand；　if　they　are
exposed　to　air　from　a　great　height；　or　from　some　very　quiet　cellar；　you
will　often　not　find　a　single　trace　of　life。

So　that　M。　Pasteur　arrived　at　last　at　the　clear　and　definite　result；
that　all　these　appearances　are　like　the　case　of　the　worms　in　the　piece
of　meat；　which　was　refuted　by　Redi；　simply　germs　carried　by　the　air　and
deposited　in　the　liquids　in　which　they　afterwards　appear。　　For　my　own
part；　I　conceive　that；　with　the　particulars　of　M。　Pasteur's　experiments
before　us；　we　cannot　fail　to　arrive　at　his　conclusions；　and　that　the
doctrine　of　spontaneous　generation　has　received　a　final　'coup　de
grace'。

You；　of　course；　understand　that　all　this　in　no　way　interferes　with　the
'possibility'　of　the　fabrication　of　organic　matters　by　the　direct
method　to　which　I　have　referred；　remote　as　that　possibility　may　be。


　　　　＇Footnote＇　1　Those　who　wish　to　study　fully　the　doctrines　of
　　　　which　I　have　endeavoured　to　give　some　rough　and　ready
　　　　illustrations；　must　read　Mr。　John　Stuart　Mill's　'System　of
　　　　Logic'。







End