PLACE OF UREA FORMATION 101 



and tissues, has been regarded as important in pathology, 

 being looked upon as especially toxic and as responsible for 

 the symptoms of intoxication appearing after administra- 

 tion of meat to animals with Eck fistulas. The import and 

 credibility of these ideas have been completely lost, however, 

 since it has been shown that anywhere, as in the urine, where 

 an ammonium salt in aqueous solution comes in contact with 

 sodium carbonate ammonium carbamate is produced, the 

 NH 3 and CO 2 being distributed proportionately to form 

 ammonium carbamate and ammonium carbonate in con- 

 nection with the disturbance of equilibrium and water 

 transportation. 5 



Place of Urea Formation. Exclusion of the Liver. 

 In literature the question of the place of urea formation 

 occupies a very disproportionate amount of space. That a 

 process of this sort actually takes place in the liver is amply 

 proved by v. Schroeder's experiments ; but it is by no means 

 settled that the liver is the sole location in which urea is 

 formed. Efforts have been made to come to some conclu- 

 sion upon this point by study of the sequels of hepatic 

 exclusion. Experiments along this line of inquiry by Nencki 

 and Pawlow (with Hahn and Mas sen) in which they made 

 use of the Eck fistula (cf. Vol. I of this series, p. 296, Chem- 

 istry of the Tissues), have become famous. Here, too, we 

 may class the experiments in Hofmeister's laboratory in 

 which the liver is destroyed by injection of acid into the 

 biliary duct, and by ligation of the hepatic vessels. In addi- 

 tion a number of observations upon nitrogen elimination in 

 acute yellow atrophy, phosphorus poisoning and hepatic 

 cirrhosis are of significance. 6 The conclusion from this 



5 J. J. Macleod and H. D. Haskins (Cleveland), Jour, of Biol. Chem., 1, 

 319, 1905. 



6 Literature upon Formation of Urea in the Living Body and its Relation 

 to Defect of Hepatic Function: M. Jacoby, Ergebn. d. PhysioL, 1, 532, 1902; 

 A. Magnus-Levy, Noorden's Handb. d. Pathol. d. Stoffw., 1, 99-117, 1906; 

 E. Weinland, Nagel's Handb. d. PhysioL, 2, 481, 1907; J. Wohlgeinuth, Handb. 

 d. Biochera., 3', 183, 1910; A. Ellinger, ibid., $', 563, 1910. 



