VITALITY OF PUTPvEFACTIVP] OEGANISMS. 207 



wide diffusion of the organisms which produce them, 

 it is impossible to conceive that they should not 

 be suspended in the atmosphere in myriads." Had 

 Professor Huxley himself made some careful and dis- 

 criminating experiments on this part of the subject, he 

 might have found that the supposed impossibility of 



conception was entirely delusive What has been 



the subsequent progress of events? In the first place, 

 it has been shown by Professor Burdon Sanderson, my- 

 self, and others, that the living Bacteria-germs are 

 not diffused through the. air to any~¥ppfe"ciable extent ; 

 ^an^rthis^Is^How a very widely accepted doctrine, in spite^ 

 of its_ heing^-jas. Professor . Huxley imagined, an im- 



possibla-CQnception.'_ „Tbe ' others 'referred to by,. Dr. 



Bastiau embrace among them, it is to be admitted, the. 

 celebrated naturalisLlkikQ. 



Dr. Bastian was quite correct in saying that the 

 'doctrine' he enunciated was, at that time, 'widely 

 accepted.' But the deportment of almost any sterilized 

 animal or vegetable infusion exposed to common air 

 will disprove the doctrine. It is irreconcileable with 

 the experiments on melon-, turnip-, cucumber-, and 

 hay-infusions, alluded to in this memoir. Such in- 

 fusions, after having been sterilized by exposure for six 

 or eight hours to the boiling-temperature, remain, if 

 protected from the Bacteria-germs of the air, for ever 

 barren ; but when infected spontaneously, or purposely, 

 by atmospheric germs, they are found, within eight and 

 forty hours after such infection, thickly crowded with 

 Bacteria. That London air is laden with living Bac- 

 teria-germs is as certain as that London chimneys are 

 laden with smoke. W?^^^ ^^* Sanderson's extremely 

 important experiments really prove is, that a mineral 

 aolutiQiLcgmpetent to nourish the Bacteria, after they^ 

 have been fully developed, is not competent (or, rather 



