The Microscope. 



•-203 



The first change that is noted is an increase of acidity. This 

 begins a short time after evacuation, and if the urine be kept in a 

 cool place, continues for twenty-four hours or more. This is called 

 the acid fermentation. The sediment examined during this period 

 shows the s])ecial microbe that causes the fermentation. It is a 

 minute spherical organism, occurring singly and in groups of two 

 or more, arranged in chains or masses. It bears a close 

 resemblandc to the tonila cerevisite. So far as I am aware, it 

 has not yet been named. According to Scherer, this microbe and 

 the bladder mucous decompose part of the urinary pigment into 

 lactic and acetic acids. These acids decompose the soluble neutral 

 urates— the form of combination in which uric acid occurs in the 

 urine — and produce first, the sparingly soluble acid urates, and 

 ultimately the almost insoluble uric acid. 



During this fermentation, then, a sediment of urates and uric 

 acid is a normal occurrence. A few crystals of calcium oxalate often 

 are present. (Fig. 1.) 



voir'/ H>, .;«',«^. **- .«. ' ,-0. Ok "Ti • rS*"*- ■© 







Fig. 1. 



Deposit in "' acid fermentation " of 

 urine : a, fungus ; 6, amorphous 

 sodium urate ; c, iirio acid ; d, cal- 

 cium oxalate. 



..6 



Fig. 2. 



Deposit in ammoniacal urine (al- 

 kaline fermentation!: a, acid ammo- 

 nium urate ; b, ammoiuo-magnesium 

 phos|)hate ; c, putrefactive micro- 

 organisms 



The influence of this microbe in the production of the acid 

 fermentation is not admitted by all observers. Briicke thinks the 

 lactic acid is formed from minute traces of sugar in the urine, 

 while according to Hofman, phosphoric acid and a basic salt are 

 formed from the acid sodium phosphate. 



Exposed a longer time, especially in a warm place, the urine 

 becomes neutral, and finally strongly alkaline in reaction — it under- 

 goes the alkaline fermentation. 



This change is the result of the decomposition of the urea into 

 carbon di-oxide and ammonia, induced by the development of the 

 Micrococcus urecc and the Bacterium urece. Every urine under- 



