VITALITY OF PUTEEFACTIVE ORGANISMS. 205 



will be the first to give way. A germ, moreover, brought 

 close to the death-point in a neutral or in an alkaline in- 

 fusion may revive, while in an acid one it may perish — 

 just as proper nutriment may rescue a dying man, while 

 improper nutriment would fail to do so. These elemen- 

 tary considerations, founded on the demonstrable fact 

 that Bacteria-genus are more fully vivified and better 

 nourished in neutral infusions than in acid ones, suffice, 

 I think, to explain the observed difference of action. 

 At all events, these are the thoughts which have be- 

 come rooted in my mind, through long observation and 

 long pondering of this question.^ 



§ 21. Remarks on the Germs of Bacteria as 

 distinguished from Bacteria themselves. 



The failure to distinguish between these stubborn 

 germs and the soft and sensitive organisms which 

 spring from them has been a source of error in writings 

 on Biogenesis. In his able and important paper, 

 ' On the Origin and Distribution of Bacteria in Water, 

 and the circumstances which determine their exist- 

 encelE^the Tissues ^andji^ Living Bod/,' 



Dr. Burdon Sanderson, for example, has described ex- 

 periments from which, in my opinion, very incorrect 

 conclusions have been drawn. He exposed to the com- 

 mon air vessels containing Pasteur's solution, which 

 when inoculated with fully developed Bacteria enables 

 them freely and copiously to increase and multiply; 



* From their deportment in boiling, I should infer that the air 

 dissolved in an alkaline liquid is in a different physical condition 

 from that dissolved in an acid liquid ; and to this, in some measure^ 

 the difference of nutritive power may be due. I have been imable 

 to find any experiments on the comparative absorption of air by 

 acid and neutral liquids. The subject is, I think, well deserving of 

 attention. 



