CONDITIONS FAVOrEING FERMENTATION. 



7 



tained that this high temperature of 122° F. (50° C.) is just as 

 favourable for the fermentation of milk and of hay-, turnip-, and 

 other vegetable infusions, as it is for urine. 



Shortly after my first announcement of this fact in June 1876*, 

 it was made known by Professor Cohnf that Dr. Eidam had also 

 discovered that certain organisms would grow and multiply rapidly 

 at this high temperature in infusions of hay, though it was one 

 which proved fatal to Bacterium termo, Torulce, and other allies. 

 He moreover stated that the organisms found under these con- 

 tions were invariably Bacilli. To this latter point I shall have to 

 return in a subsequent part of this communication. 



What I have now to say concerning the simple influence of 

 122° r. as an initiator and promoter of fermentation in boiled 

 fluids may be comprised in a very few words. 



AYhere the initial acidity of urine, is such that it requires 

 less, or not more than 6 minims (1$ per cent.) of liquor potasssej 

 to the ounce (of 480 minims) to ensure its neutralization, I have 

 found that such a fluid after it has been boiled 2" over the flame 

 and 5 "-10" in a can of boiling water, will almost invariably fer- 

 ment in 15-48 hours if kept at a temperature of 122° r,§, though 

 it will rarely or ever undergo this change at a temperature of 

 77°-86° F. 



Where the acidity corresponds to 7 minims of liquor potassae per 

 ounce, a specimen of urine, boiled as above, sometimes ferments 

 and sometimes does not. A urine whose acidity equals 8 minims 

 of liquor potassae per ounce (nearly 1| per cent.) has only been 

 known to ferment on two or three occasions out of numerous trials ; 

 and where the acidity has been higher than this, the fluid has in- 

 variably remained barren under the stimulus of a temperature 

 of 122° F. acting alone — that is, without the additional aid of 

 other promoters, such as oxygen or liquor potassse. 



When a urine whose initial acidity equals seven or eight minims 

 of liquor potassae per ounce has fermented after boiling, this has 

 been sometimes attributable to the fact that the specimen in ques- 



* Proceedings of Eoyal Society, No, 172, vol. xxv. p. 149. 



t Beitrage zur Biolog. der Pflanzen, Ed. ii. Hft. 2, 1876, p. 268. 



\ A 5'84-per-cent. solution (see p. 16). 



§ I have, however, found a diabetic urine of five miuiiiiB of acidity (sp. gr. 

 1040) invariably remain pure after a short boiling, even when kept at a heat 



of F. 



