108 MICROBES, FERMENTS, AND MOULDS. 



it may be ascertained that the ferment was introduced 

 by some accidental cause, such as a surgical examina- 

 tion, and that the sound served to convey the microbe. 

 It is, in any case, sufficiently common at the exterior 

 orifice of the urethra, and at the depth of two or three 

 centimetres. 



Von Tieghem has shown by precise experiments 



Fig. 59. Micrococcus urea (Von Tieghem). Microbe of amraoniacal fermentation. 

 It may be observed that the bacterium is in the figure 8, or in chaplets. (Much 

 magnified.) 



that the presence of this microbe is the true cause of 

 the ammoniacal fermentation of urine. With certain 

 precautions, the urine withdrawn from a healthy 

 bladder may be preserved for an indefinite time. 



These experiments have been recently resumed by 

 Sternberg, an American physician, who has clearly 

 demonstrated that only the microbes of the air, or 



