CASUAL URINARY CONSTITUENTS. 735 



By substituting one of the hydrogen atoms in the NH 2 group of 

 normal a- -amino-acids by an alkyl radical (methyl) the combustion of the 

 acids of the series C 2 and 4 is considerably retarded and almost entirely 

 prevented in the members of the 5 and C 6 series (FRIEDMANN). Sar- 

 cosine (methyl glycocoll), (CH 3 )NH.CH 2 .COOH, is not readily burnt, and 

 therefore passes in great part unchanged into the urine, but perhaps also 

 passes in small part into the corresponding uramino-acid, methylhydan- 

 toic acid, XH 2 .CO.N(CH 3 ).CH 2 .COOH (ScnuLTZEN 1 ), is an example of this 

 kind. The substitution of both hydrogen atoms of the NH 2 group by 

 methyl radicals does not seem to make the demolition of the amino-acids 

 more difficult (FRIEDMANX). The a -amino-acids with branched carbon 

 chains behave differently in the body from the n-amino-acids, and the 

 formation of /?-oxybutyric acid and acetoacetic acid, which will be dis- 

 cussed on page 775, is an example. No general rule for the mode of 

 demolition of the amino-acids can be given (FRIEDMANN 2 ) . 



The nitrites, including hydrocyanic acid, pass, according to LANG, into 

 sulphocyanide combinations, and this sulphocyanide apparently originates 

 from the non-oxidized sulphur of the proteins, which is readily split off. 

 PASCHELES' observations indicate that, in an alkaline reaction and at the 

 temperature of the body, this sulphur can readily convert the alkali- 

 cyanides into sulphocyanides. The alkali sulphocyanides when ingested 

 are almost quantitatively eliminated in the urine, according to POLLAK. S 



By substitution with halogens, bodies otherwise readily oxidizable are 

 converted into difficultly oxidizable ones. While the aldehydes are readily 

 and completely burnt like the primary and secondary alcohols of the fatty 

 series, the halogen substituted alhedydes and alcohols are, on the contrary, 

 difficultly oxidizable. The halogen substitution products of methane 

 (chloroform, iodoform, and bromoform) are at least in part destroyed 

 and the corresponding alkali compounds of the halogen pass into the urine. 4 



By conjugation with sulphuric acid, the alcohols which are otherwise 

 readily oxidizable may be guarded against combustion, and conse- 

 quently the alkali salt of ethylsulphuric acid is not burnt in the body 

 (SALKOWSKI 5 ) . 



The organic combinations containing sulphur act differently. Taurine, 



1 Ber. d. deutsch. chem. Gesellsch., 5. See also Baumann and v. Mering, ibid., 8, 

 584, and E. Salkowski, Zeitschr. f. physiol. Chem., 4, 107. 



2 Hofmeister's Beitrage, 11. 



3 Lang, Arch. f. exp. Path. u. Pharm., 34; Pascheles, ibid.; Pollak, Hofmeister's 

 Beit rage, 2. 



4 See Harnack and Griindler, Berlin, klin. Wochenschr., 1883; Zeller, Zeitschr. f 

 physiol. Chem., 8; Kast, ibid., 11; Binz, Arch. f. exp. Path. u. Pharm., 28; Zeehuisen, 

 Maly's Jahresber., 2JJ. 



5 Pfliiger's Arch., 4. 



