the Urine in Man and Carnivormis Animals. 479 



the hydrochloric acid withdraws lime from the phosphate of 

 lime; potash, or soda, chloride of calcium, or chloride of so- 

 dium or potassium, is formed on the one hand, and acid phos- 

 phate of soda or potash, or acid phosphate of lime, on the 

 other; or acetic acid, paratartaric acid, or citric acid, are libe- 

 rated by the decomposition of the salts of these vegetable acids 

 contained in the aliments. At a certain stage of digestion the 

 chyme will, according to the nature of the food partaken of, 

 contain acid phosphates or free vegetable acids ; and it is only 

 upon the supply of gastric juice continuing, that thus, upon the 

 amount of the hydrochloric acid increasing, we may detect, by 

 analysis, free hydrochloric acid in the chyme ; the gastric juice 

 taken from an empty stomach contains invariably Iree hydro- 

 chloric acid or acid phosphates. 



With respect to the essential organic constituents of urine, 

 I have already treated of the origin of urea and uric acid in 

 my " Chemistry applied to Physiology and Pathology;" and 

 I will here merely add a few words on the presence of am- 

 monia in urine. 



Ammonia is a product of the putrefaction of nitrogenous 

 substances, and as such might be a purely accidental consti- 

 tuent of the healthy animal body, and of its secretions. In 

 consequence of certain processes which take place in the or- 

 ganism independently of the vital process, all the fluids in the 

 body may of course become rich in ammonia, or in ammo- 

 niacal salts. Healthy urine contains only very minute or 

 doubtful traces of ready-formed ammonia, and these traces 

 existed probably already in the food partaken of. Fresh urine 

 evolves ammonia when treated with alkalies, but it yields no 

 precipitate with chloride of platinum. Dr. Schlossberger made 

 certain experiments to this effect in the laboratory at Giessen; 

 upon treating fresh urine with chloride of platinum, and al- 

 lowing the mixture to stand at rest during the night, crystals 

 were formed in the urine, which, upon examination, manifested 

 all the properties of chloride of platinum and potassium. The 

 amount of ammonia formed in the healthy organism is likewise 

 very minute, not being sufficient even to neutralize the acid 

 from which proceeds the acid reaction of urine and of saliva. 

 We cannot assume the presence of any ammoniacal salt in the 

 urine of herbivorous animals, which contains fixed or alkaline 

 carbonates. 



The carbonate of ammonia which Chevreul found as a con- 

 stituent of the urine of the camel, was either a product of pu- 

 trefaction, or an accidental constituent of this urine, since the 

 carbonate of ammonia is a volatile substance, and must find 



