384 PHYSIOLOGICAL CHEMISTRY. 



mixed diet. On a mixed diet the average amount of ammonia 

 eliminated by the urine is about 0.7 grm. NH 3 per twenty-four 

 hours (NEUBAUER). 



The quantity of ammonia in human urine and that of carnivora 

 is increased by the introduction of mineral salts and also in diseases 

 in which an increased formation of acid takes place due to an in- 

 creased metabolism of proteids. This is the case in fevers and 

 diabetes. In the last-mentioned disease an organic acid, /?-oxybu- 

 tyric acid, is produced (MINKOWSKI, KULZ, STADELMAKN) which 

 passes into the urine combined with ammonia. In diseases of the 

 liver, as in acute yellow atrophy and interstitial hepatitis (HALLER- 

 VORDEH, STADELMANN), the formation of urea may decrease and 

 the elimination of ammonia increase. In these cases the propor- 

 tion of NH 3 : Ur, which, according to STADELMAKX, is normally 

 2.8 : 100, may be changed. The same may also be observed in 

 acute phosphorus-poisoning. In such a case K. MORNER found 

 the relation 5.2 : 100. 



The detection and quantitative estimation of ammonia is per- 

 formed according to the method suggested by SCHLOSING. The 

 principle of this method is that the ammonia from a measured 

 amount of urine is set free by lime-water in a closed vessel and 



N 



absorbed by a measured amount of JA sulphuric acid. After the 



absorption of the ammonia the quantity is determined by titrating 



N 

 the remaining free sulphuric acid with a JQ caustic alkali. This 



method gives low results, and in exact work we must proceed as 

 suggested by BOHLAND (PFLUGER'S Archiv, vol 43, page 32). Other 

 methods have been suggested by SCHMIEDEBERG and by LATSCHEN- 



BERGER. 



Calcium and magnesium occur in the urine for the most part as 

 phosphates. The quantity of earthy phosphates eliminated daily 

 is somewhat more than 1 gr., and of this amount f is magnesium 

 and | calcium phosphate. In acid urines the simple- as well as the 

 double-acid earthy phosphates are found, and the solubility of the 

 first, among which the calcium-salt, CaHP0 4 , is especially insol- 

 uble, is particularly augmented by the psesence of double-acid al- 

 kali phosphate and sodium chloride in the urine (OTT). The quan- 



