THE BEGINNINGS OF IIFE. 



strong infusions frequently changed, whilst weak ones 

 might be preserved; and that even a strong infusion 

 might be prevented from undergoing change, if the 

 period of ebullition were sufficiently prolonged. Prof. 

 Cantoni also found that Vlhriones were plentifully pro- 

 duced within such flasks when very strong organic 

 fluids were employed, and when the daily temperature 

 of the air was not less than 77°F i. 



The fluids most frequently employed by M. Pasteur 

 were yeast-water, yeast-water sweetened by sugar, urine, 

 infusion of beet-root, and infusion of pear. 



Taking urine as a fair example of such a fluid, I 

 have found that the statements of M. Pasteur and of 

 Prof. Lister are perfectly correct. This fluid may 

 generally remain for an indefinite period in such 

 vessels without becoming turbid, or undergoing any 

 apparent change. The same is generally found to be 

 the case with an infusion of turnip; and occasionally 

 an infusion of hay may be similarly prevented from 

 undergoing fermentation. On the other hand, if the 

 turnip-solution be neutralized by the addition of a little 

 ammonic carbonate, or liquor potassse ; or, better still, 

 if even half a gi^in of new cheese be added to the 



^ After speaking of the vital resistance to ^heat of Vibriones, he says 

 (' Gaz. Med. Itahana-Lombardia,' serie vi. torn. I. 1868) : — ' The tempe- 

 rature at which the production of Vibrio7ies ceases in an organic solution 

 varies with the quality of the organic matter dissolved in it, with the 

 quantity of air enclosed in the flasks together with the solution, and also 

 (and more notably) with the temperature of the air in which the flasks 

 are kept after being heated.' 



