4o8 



ALKALINE FERMENTATION OF URINE. 



accidentally. While the urine is still acid, it becomes turbid and contains nitrous 

 acid, whose source is entirely unknown. According to v. Voit and Hof mann phos- 

 phoric acid and a basic salt are formed 

 from acid sodium phosphate, whereby 

 part of the uric acid is displaced from 

 sodium urate, thus causing the forma- 

 tion of an acid urate. 



Alkaline Fermentation. When urine 

 is exposed for a still longer time, more 

 especially in a warm place, it becomes 

 neutral and ultimately ammoniacal, i.e., 

 it undergoes the alkaline fermentation 



(fig- 261). 



This condition is accompanied by the 



formation of the micrococcus urese (fig. 



262) (Pasteur, Colin) and Bacterium ureae 



(fig. 261), which causes the urea to take 



up water, and decompose into C0 2 and 



Fig. 261. ammonia. 



Deposit in ammoniacal urine (alkaline fermenta- Urea [CO(HN 2 ) 2 + 2(H 2 0) = ammo- 



tion). a, acid ammonium urate ; b, ammonio- n j um car bonate [(NH 4 ) 2 C0 3 ]. 



magnesium phosphate ; c, bacterium urea. ^ ^^ of decomposing urea belongs 



to many different kinds of bacteria, including even the sarcina of the lungs whose germs seem 

 to be universally diffused in the air. These organisms produce a soluble ferment (Musculus), 

 which, however, only passes from the body of the cells into the fluid after the cell or organism 

 has been killed by alcohol {Lea). 



The presence of ammonia causes the urine to become turbid, and those substances 

 which are insoluble in an alkaline urine are precipitated earthy phosphates, con- 

 sisting of the amorphous calcic phosphate, acid ammo- 

 nium urate (fig. 261, a), in the form of small dark granules 

 covered with spines ; and, lastly, the large clear knife-rest 

 or " coffin-lid " form of ammonio-magnesic phosphate, 

 or triple phosphate (fig. 282). [The last substance 

 does not exist as such in normal urine, but it is formed 

 when ammonia is set free by the decomposition of urea, 

 the ammonia uniting with the magnesium phosphate. 

 Its presence therefore always indicates ammoniacal fermentation of the urine.] In 

 cases of catarrh or inflammation of the bladder, this decomposition may take 

 place within the bladder, when the urine always contains pus-cells (fig. 267) and 

 detached epithelium. When much pus is present, the urine contains albumin. 

 Ammoniacal urine forms white fumes of ammonium chloride, when a glass rod 

 dipped in hydrochloric acid is brought near it. [When ammonia is added to normal 

 urine, triple phosphate is precipitated in a feathery form (fig. 283).] 



[Significance of Triple Phosphate. If urine be alkaline when it is passed, and the alkalinity 

 be due to a volatile alkali, i.e., to NH 3 , then decomposition of the urine has taken place, and 

 this kind of urine is a sure sign that there is disease of the genito-uriuary mucous membrane.] 



264. ALBUMIN IN URINE OR ALBUMINURIA. Serum-albumin is the 

 most important abnormal constituent in urine which engages the attention of the 

 physician. It occurs in blood ( 32), and its characters are described in 249. 



Causes of Albuminuria. 1. Serum-albumin may appear in urine without any apparent 

 anatomical or structural change of the renal tissues. This condition has been called by v. 

 Bamberger "Hematogenous albuminuria." It occurs but rarely, however, and sometimes in 

 healthy individuals when there is an excess of albumin in the blood-plasma {e.g., after suppres- 

 sion of the secretion of milk), and after too free use of albuminous food. 2. As a result of 

 increased blood-irressure in the renal vessels, e.g., after copious drinking. It may be temporary, 



f s #'r>. 



Fig. 262. 

 Micrococcus ureae. 



