THE AMMONIACAL DECOMPOSITION OP URINE. 373 



could be abundantly demonstrated^ and to the presence of these 

 the destruction of the urea was to be traced. 



The importance of these experiments was at once manifest, 

 not only as giving a clearer explanation of the changes in 

 urine, but also as indicative of the cause in fermentation gene- 

 rally, and in the present day we all recognise the importance 

 of Pasteur's work as being the foundation of our methods of 

 inquiry into the causes of infectious diseases. 



Two questions now naturally present themselves for con- 

 sideration : 



1. Whether these organisms, which cause the alkaline fer- 

 mentation, always gain admission from without, or whether 

 freshly voided urine contains such germs, so that unboiled urine, 

 carefully protected from contact with the air, may still de- 

 compose ; which would admit of the conclusion that the 

 elements of fermentation do not always arise from without? 



2. What particular organism causes the alkaline fermenta- 

 tion, or are several kinds involved ? 



(1) As regards the entrance of the organism. It has been 

 shown by Cazeneuve^ and Livon, and Meissner^ that perfectly 

 fresh urine may be preserved free from any fermentative change 

 by eliminating the possibility of the entrance of air and germs, 

 and Professor Leube, by a series of ingenious experiments, has 

 shown that normal urine, on its exit from the bladder, contains 

 neither fungi nor germs, the development of Avhich would cause 

 decomposition of the urea. Further, by the exposure for a few 

 minutes of nutrient gelatine in shallow glass vessels such as 

 those used in plate cultivations, micro-organisms may be culti- 

 vated from the air, which, when isolated, are found to be 

 capable of giving rise to the decomposition of sterilised urine, 

 and which, in form and general characters, are found to be 

 identical with the organisms present in decomposed urine. 



(2) Is the ammoniacal change in urine due to the presence of 

 one or more organisms? It is with the object particularly of 

 dealing with this question that I have lately carried on an in- 



1 ' Comptes rendus,' T. Ixxxiv, p. 571, 1S77. 



2 ' Deutsche Zeitschrift fiir Chirurgie,' Bd. xiii, p. M4:, 1880. 



VOL. XXVIl, PART 3. NEW SER. D D 



