204 THE INCOME OF ENERGY 



Prior to 1860 ammoniacal decomposition of 

 urine was vaguely classed as a fermentation. In 

 that year Muller 1 suggested that it might be due 

 to a body like beer-yeast. In 1862 Pasteur 2 

 discovered such a yeast, which he called Torula 

 urece. Cohn first classed it with the micrococci. 

 It is aerobic. Miguel finds seven species of 

 bacilli, nine micrococci, and one sarcina, that 

 decompose urea. These obtain their nitrogen 

 ordinarily from proteids, but in the absence of 

 proteids may utilize urea. 



Extraction of Urease. To 10 C.C. of urine 

 undergoing an active ammoniacal fermentation, 

 add 50 c.c. of strong alcohol, and allow the 

 mixture to stand in a well-corked flask. After 

 five days place the precipitate upon a very small 

 filter and wash it with 50 c.c. of fresh alcohol. 

 (Preserve both filtrates for recovery of the alcohol 

 by redistillation.) 



1. Add a very small quantity of this precip- 

 itate to a neutral 2 per cent solution of urea. 

 Test the reaction. Place the mixture in a water 

 bath at 38 C. 



After a few minutes again test the reaction. 



It will be strongly alkaline. 



1 Miiller: Journal fur praktische Chemie, 1860, Ixxxi, p. 467. 



2 Pasteur : Comptes rendus de 1'academie des sciences, Paris, 

 1860, 1, p. 869. See also Van Tieghem, idem, 1864, p. 210. 



