676 URINE. 



seems not to take place, or not to the same extent, 1 and this is given as 

 a reason why herbivora soon die when acids are given. This is true at 

 least for rabbits, while according to BAER this power of increasing the 

 elimination of ammonia exists also in the goat, monkey, and pig, hence 

 no definite difference in this regard exists between herbivora and carnivora. 

 The differences which have been observed are, according to EPPINGER, 

 not of a special kind, and they may be caused, he says, from a different 

 amount of protein in the food which yields ammonia. Thus dogs with 

 food poor in protein behave like rabbits while, according to EPPINGER, 

 in herbivora (rabbits) a de-toxification of the acid can be brought about 

 by the abundant supply of proteins or their cleavage products. The 

 correctness of this statement is still disputed (POHL) or has only been 

 partly confirmed (BOSTOCK). The point is disputed and it must not be 

 forgotten that, as A. LoEWY 2 found, the sensitiveness toward the action 

 of acids varies very much in different individuals. 



Although one cannot raise the degree of acidity of the urine above a 

 certain limit by the introduction of acid, still it may be easily diminished, 

 so that the reaction becomes neutral or alkaline. This occurs after the 

 taking of carbonates of the .fixed alkalies or of such alkali salts of vege- 

 table acids citric acid, and malic acid as are easily burned into car- 

 bonates in the organism. Under pathological conditions, as in the 

 absorption of alkaline transudates, or the alkaline fermentation within 

 the bladder, the urine may become alkaline. 



A urine with an alkaline reaction caused by fixed alkalies has a very 

 different diagnostic value from one whose alkaline reaction is caused by 

 the presence of ammonium carbonate. In the latter case we have to 

 deal with a decomposition of the urea of the urine by the action of micro- 

 organisms. 



If one wishes to determine whether the alkaline reaction of the urine 

 is due to ammonia or to fixed alkalies, a piece of red litmus paper is dipped 

 into the urine and allowed to dry exposed to the air or to a gentle heat. 

 If the alkaline reaction is due to ammonia, the paper becomes red again; 

 but if it is caused by fixed alkalies, it remains blue. 



Determination of the Acidity. As the quantity of phosphoric acid 

 present as dihydrogen salt, as above stated, cannot be used as a measure 

 of the acidity, none of the older methods suggested for the. estimation 

 of this portion of the phosphoric acid is suited for acidity determinations. 



1 See Winterberg, Zeitschr. f. physiol. Chem., 25, and J. Baer, Arch. f. exp. Path. u. 

 Pharm., 64. 



2 Eppinger, Zeitschr. f. exp. Path. u. Therap., 3; with Tedesko, Bioch. Zeitschr., 

 16; Pohl. ibid., 18; Staal, Zeitschr. f. physiol. Chem., 58; Bostock, ibid., 84; A. 

 Loewy, Centralbl. f. Physiol., 20; 337. 



