POLYPEPTIDES AND AMINO- ACIDS. 717 



bases. The existence of this acid is disputed by BONDZYNSKI, DOM- 

 BROWSKI and PANEK. The investigations of GINSBERG also contradict 

 the occurrence of such an acid, because no sulphuric acid could be split 

 off from the mixture of the oxyproteic acids by hydrolysis. 



Methods for the quantitative estimation of the total oxyproteic acids 

 have been suggested by GINSBERG and by GAWINSKI 1 . According to 

 their determinations in man with a mixed diet the nitrogen of the oxypro- 

 teic acids represented 3-6.8 per cent of the total nitrogen, and with a 

 milk diet it sinks to about one-half of this (GAWINSKI). In dogs it 

 amounts to 2 per cent of the total nitrogen (GINSBERG). In disease it 

 may rise, and in typhoid cases it may rise to 14.69 per cent of the total 

 nitrogen (GAWINSKI). In phosphorus poisoning this nitrogen fraction 

 is also markedly increased according to several observations. The 

 oxyproteic acids are considered, as above remarked, as intermediary 

 products of the protein metabolism, and GAWINSKI holds that the 

 elimination of their nitrogen runs parallel with the elimination of neutral 

 sulphur, so that this latter may serve as an approximate measure of the 

 elimination of these acids. 



ABDERHALDEN and PREGL 2 have shown that human urine normally contains 

 compounds which stand, perhaps, in close relation to the polypeptides, and which 

 on hydrolysis with acids yield at least a part of the moities existing in the 

 protein molecule. In the case investigated they obtained abundant glycocoll, 

 also leucine, alanine, glutamic acid, phenylalanine, and probably also aspartic 

 acid. The relation between these polypeptide-like bodies and the above-men- 

 tioned proteic acids and uroferric acid has not been investigated. 



Non-dialyzable substances, the so-called adialyzable bodies, or bodies that dialyze 

 with difficulty, also occur in the urine. They consist in part of chrondroitin- 

 sulphuric acid whose daily amount, according to PONS, is 0.08-0.09 gram, and 

 also of nucleic acid, mucoids and unknown bodies. SASAKI found 0.218-0.68 

 gram of such bodies per liter of normal urine, and EBBECKE found 1.44 grams 

 in men. In pregnant women SAVARE found somewhat higher results (0.6 gram 

 per liter) than in non-pregnant women (0.4 gram). The quantity is increased 

 in fevers, in pneumonia (EBBECKE), in nephritis, and especially in eclampsia, 

 where SAVARE 3 indeed in one case found 13.84 grams per liter. The adialyzable 

 bodies occurring in eclampsia are toxic. 



Amino-acids may, when they are introduced into the body in large amounts, 

 also pass in part into the urine. This has been shown for r-alanine by R. HIRSCH 

 in the dog, and by PLAUT and REESE in dog and man, and for r-leucine by 

 ABDERHALDEN and SAMUELY * in rabbits. EMBDEN and REESE, FORSSNER, 

 ABDERHALDEN and SC^TTENHELM, SAMUELY, EMBDEN and MARX 5 were able, 



1 Gawinski, Zeitschr. f. physiol. Chem., 58. ; Ginsberg, Hofmeister's Beitrage, 10. 



2 Zeitschr. f. physiol. Chem., 46. 



3 Pons, Hofmeister's Beitrage, 9; Sasaki, ibid., 9; Savare, ibid., 9 and 11; Ebbecke, 

 Bioch. Zeitschr., 13. 



4 R. Hirsch, Zeitschr. f. exp. Path. u. Therap., 1; Plaut and Reese, Hofmeister's 

 Beitrage, 7; Abderhalden and Samuely, Zeitschr. f. physiol. Chem., 47. 



5 Forssner, Zeitschr. f. physiol. Chem., 47; Abderhalden and Schittenhelm, ibid., 

 47; Samuely, ibid., 47; Embden and Reese, Hofmeister's Beitrage, 7, with Marx, 



