Vaccine Irtoculalion. 279 



•iclUmetre of air. This air, which circulates, certainly 

 ferves, as in the animal body, to coagulate the fibrous part 

 by abibrption of oxygen. The chifea is a milky plant, and 

 elaftic gluten is formed in it. 



** Though the puritv of the atmofpheric air amounts her^ 

 particularly in the night, to 0-305 of oxvgen, I have found 

 that the air contained in the pods and capfules of equino6iial 

 plants, for inftance the paullinia, is more azotous than our 

 atmofpheric air. It does not exceed o'24 or 0*25 of oxvgen. 

 The air in the culmi gen'iculati\\evt,h^son\y O'l^ of oxygen. 

 All this proves that the air which circulates is purer, and 

 that the air which is in a ftate of reft, depofited in the cap- 

 liles or utricuVi, is lefs pure than atmofpheric air. The 

 bonier is recently produced by the organs which docompofe 

 the vater: it proceeds to thofe parts where it ought to fervc, 

 by it. abundance of o-xygcn, to precipitate the fibrous prin- 

 ciple I* form the fibrous tifl'ue. The other is the refiduum 

 ot a ga.^liich has already difcharged thefe functions. 



^ALEX. HUMBOLDT." 



VACCINE INOCULATIOX. 

 Tranjlalion f a Letter to George Pear/on, M. D. Phjficuzn 

 '- the Vaccine Injhiut'ion at London, 

 ^"^^i " Paris, Germinal 14, (May 5,) i?oo. 



" \\e nave een mformed by the public journals of the 

 trials made \n Ei1\and with regard to the vaccine inoculation, 

 the fucccfs of wftii has, in a great meafure, been owing to 

 your eidightcned a,/. Some friends of humanity, and of 

 that fcience whicl.you cultivate in fo diftinguifhed a man- 

 ner, have formed alan for introducing into France a prac- 

 tice which feems to -omife advantages of fo much magni- 

 tude. For this pur[fe they have propofed a fubfcription, 

 which is now nearhfiUcd up. You will find annexed a 

 profpe£lus of their pi. • but, to carry into execution the 

 views announced in xi,,^ have need of your afliftance; and 

 we now folicit it with c^fidcnce. 



" Though fame trii have been made here in regard to 



the vaccine inoculalion,nth which the Schogl of Medicine 



9 has 



