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 uree (Von Tieghem). Microbe of ammontacal 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precautions, the urine withdrawn from a healthy 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 
