yeast-第4章

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disturbance；　and　only　recently　the　study　of　the　phenomena　which
accompany　vaccination　has　thrown　an　immense　light　in　this　direction；
tending　to　show　by　experiments　of　the　same　general　character　as　that　to
which　I　referred　as　performed　by　Helmholz；　that　there　is　a　most
astonishing　analogy　between　the　contagion　of　that　healing　disease　and
the　contagion　of　destructive　diseases。　　For　it　has　been　made　out　quite
clearly；　by　investigations　carried　on　in　France　and　in　this　country；
that　the　only　part　of　the　vaccine　matter　which　is　contagious；　which　is
capable　of　carrying　on　its　influence　in　the　organism　of　the　child　who　is
vaccinated；　is　the　solid　particles　and　not　the　fluid。　　By　experiments
of　the　most　ingenious　kind；　the　solid　parts　have　been　separated　from
the　fluid　parts；　and　it　has　then　been　discovered　that　you　may　vaccinate
a　child　as　much　as　you　like　with　the　fluid　parts；　but　no　effect　takes
place；　though　an　excessively　small　portion　of　the　solid　particles；　the
most　minute　that　can　be　separated；　is　amply　sufficient　to　give　rise　to
all　the　phenomena　of　the　cow　pock；　by　a　process　which　we　can　compare　to
nothing　but　the　transmission　of　fermentation　from　one　vessel　into
another；　by　the　transport　to　the　one　of　the　torula　particles　which
exist　in　the　other。　　And　it　has　been　shown　to　be　true　of　some　of　the
most　destructive　diseases　which　infect　animals；　such　diseases　as　the
sheep　pox；　such　diseases　as　that　most　terrible　and　destructive　disorder
of　horses；　glanders；　that　in　these；　also；　the　active　power　is　the
living　solid　particle；　and　that　the　inert　part　is　the　fluid。　However；
do　not　suppose　that　I　am　pushing　the　analogy　too　far。　　I　do　not　mean　to
say　that　the　active；　solid　parts　in　these　diseased　matters　are　of　the
same　nature　as　living　yeast　plants；　but；　so　far　as　it　goes；　there　is　a
most　surprising　analogy　between　the　two；　and　the　value　of　the　analogy
is　this；　that　by　following　it　out　we　may　some　time　or　other　come　to
understand　how　these　diseases　are　propagated；　just　as　we　understand；
now；　about　fermentation；　and　that；　in　this　way；　some　of　the　greatest
scourges　which　afflict　the　human　race　may　be；　if　not　prevented；　at
least　largely　alleviated。

This　is　the　conclusion　of　the　statements　which　I　wished　to　put　before
you。　　You　see　we　have　not　been　able　to　have　any　accessories。　　If　you
will　come　in　such　numbers　to　hear　a　lecture　of　this　kind；　all　I　can　say
is；　that　diagrams　cannot　be　made　big　enough　for　you；　and　that　it　is　not
possible　to　show　any　experiments　illustrative　of　a　lecture　on　such　a
subject　as　I　have　to　deal　with。　　Of　course　my　friends　the　chemists　and
physicists　are　very　much　better　off；　because　they　can　not　only　show　you
experiments；　but　you　can　smell　them　and　hear　them！　　But　in　my　case　such
aids　are　not　attainable；　and　therefore　I　have　taken　a　simple　subject　and
have　dealt　with　it　in　such　a　way　that　I　hope　you　all　understand　it；　at
least　so　far　as　I　have　been　able　to　put　it　before　you　in　words；　and
having　once　apprehended　such　of　the　ideas　and　simple　facts　of　the　case
as　it　was　possible　to　put　before　you；　you　can　see　for　yourselves　the
great　and　wonderful　issues　of　such　an　apparently　homely　subject。







End