FORMATION OF UREA. 685 



or, in short experiments, at least a strongly diminished elimination of 

 urea should occur. As at least a part of the urea is formed in the liver 

 from ammonium compounds, a simultaneous increase in the elimination 

 of ammonia is to be expected. 



The extirpation and atrophy experiments made on animals by dif- 

 ferent methods 1 have shown that sometimes a rather marked increase 

 of ammonia and a diminished elimination of urea takes place after the 

 operation, but that there are also cases in which, irrespective of the pro- 

 nounced atrophy, an abundant formation of urea occurs, and no appre- 

 ciable, if any, change in the proportion of ammonia to the total nitrogen 

 and urea is observed. After shutting out from the circulation the organs 

 of the posterior part of the body, especially the liver and kidneys, KAUF- 

 MANN 2 also found an important increase in the urea of the blood, and these 

 different observations show that the liver is not the only organ, in the 

 various animals experimented upon, in which urea is formed. 



The observations made by numerous investigators 3 on human beings 

 with cirrhosis of the liver, acute yellow atrophy of the liver, and phos- 

 phorus poisoning have led to the same result. These investigations 

 teach that in certain cases the proportion of the nitrogenous substances 

 may be so changed that urea is only 50-60 per cent of the total nitrogen, 

 while in other cases, on the contrary, even in very extensive atrophy 

 of the liver-cells, the formation of urea is not diminished, neither is the 

 proportion between the total nitrogen, urea, and ammonia essentially 

 changed. Even in the cases in which the formation of urea was relatively 

 diminished and the elimination of ammonia considerably increased, fur- 

 ther investigation must be instituted before it will be possible to assume 

 a reduced ability of the organism to produce urea. An increased elimi- 

 nation of ammonia may, as shown by MUNZER in the case of acute 

 phosphorus poisoning, be dependent upon the formation of abnormally 

 large quantities of acids, caused by abnormal metabolism, and these acids 

 require a greater quantity of ammonia for their neutralization according 

 to the law of elimination of ammonia. That an abnormal formation 



1 Nencki and Hahn, 1. c.; Slosse, Arch. f. (Anat. u.) Physiol., 1890; Lieblein, Arch, 

 f. exp. Path. u. Pharm., 33; Nencki and Pawlow, Arch, des science, biol. de St. Pe"ters- 

 bourg, 5. See also v. Meister, Maly's Jahresber., 25; Salaskin and Zaleski, Zeitschr. f . 

 physiol. Chem., 29; Fischler and Bardach, ibid., 78. 



2 Compt. rend. soc. biol., 46, and Arch, de Physiol. (5), 6. 



3 See Hallervorden, Arch. f. exp. Path. u. Pharm., 12; Weintraud, ibid., 31; Miinzer 

 and Winterberg, ibid., 33; Stadelmann, Deutsch. Arch. f. klin. Med., 33; Fawitzki, 

 ibid., 45; Munzer, ibid., 52; Frankel, Berlin, klin. Wochenschr., 1878; Richter, ibid., 

 1896; Morner and Sjoqvist, Skand. Arch. f. Physiol., 2, and Sjoqvist, Nord. Med. 

 Arkiv, 1892; Gumlich, Zeitschr. f. physiol. Chem., 17; v. Noorden, Lehrb. d. Pathol. 

 des Stoffwechsels, 2. Aufl., Bd. 1, 104. 



