CASUAL URINARY CONSTITUENTS 743 



that these hydroxyl derivatives are eliminated as conjugated ghicuronic 

 acids. Conjugated glucuronic acids are detected in the urine after the 

 introduction of various substances into the organism, e.g., therapeutic 

 agents, such as terpenes, borneol, menthol, camphor (camphoglucuronic 

 acid was first observed by SCHMIEDEBERG), naphthalene, oil of turpentine, 

 oxyquinolines, antipyrine, and many other bodies. 1 Orthonitrotoluene in 

 dogs passes first into o-nitrobenzyl alcohol and then into a conjugated 

 glucuronic acid, uronitrotoluolic acid (JAFFE 2 ). The glucuronic acid split 

 off from this conjugated acid is levogyrate and hence is not identical, but 

 only isomeric, with the ordinary glucuronic acid. Dimethylaminobenzal- 

 dehyde, according to JAFFE, is converted in part into dimethylaminoben- 

 zoglucuronic acid in rabbits. The same conjugated glucuronic acid is also 

 produced, according to HILDEBRANDT, 3 from p-dimethyltoluidine, which 

 is first changed into p-dimethylaminobenzoic acid. Indol and skatol seem, 

 as above stated (page 695), to be eliminated in the urine partly as con- 

 jugated glucuronic acids. 



A synthesis in which compounds containing sulphur, mercapturic acids, 

 are formed and eliminated after conjugation w T ith glucuronic acid, occurs 

 when chlorine and bromine derivatives of benzene are introduced into the 

 organism of dogs (BAUMANN and PREUSSE, JAFFE). Thus chlorbenzene 

 combines with cysteine, forming chlorphenylmercapturic acid, CiiH 12 ClSXO 3 . 

 The important investigations of FRIEDMANN 4 show that the phenylthio- 

 lactic acid which forms the foundation of the mercapturic acids belongs 

 to the /9-series, and in this way the direct chemical connection of this body 

 with the protein-cystine (a-amino-/?-thiolactic acid) is established. FRIED- 

 MANN has also been able to convert cysteine into bromphenylmercapturic 

 acid. 



Pyridine, C 5 H 5 N, which does not combine either with glucuronic acid 

 or with sulphuric acid after previous oxidation, shows a special behavior. 

 It takes up a methyl group as found by His and later confirmed by COHN, 

 and forms an ammonium combination, methylpyridylammonium hydroxide, 

 HO.CH 3 .NC 5 H5, while in rabbits it occurs unchanged in the urine, accord- 

 ing to ABDERHALDEN, BRAHM and SCHITTENHELM. S 



1 See O. Kiihling, 1. c., which gives the literature up to 1887; also E. Kiilz, Zeitschr, 

 f. Biologie, 27; the works of Hildebrandt, Fromm and Clemens, see footnote 6, 

 page 742; Brahm, Zeitschr. f. physiol. Chem., 28; Fenyvessy, ibid., 30; Bonanni. 

 Hofmeister's Beitrage, 1; Lawrow, Ber. d. d. chem. Gesellsch., 33. 



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



3 Jaffe, Zeitschr. f . physiol. Chem., 43; Hildebrandt, Hofmeister's Beitrage, 7. 



4 Baumann and Preusse, Zeitschr. f. physiol. Chem., 5; Jaffe", Ber. d. deutsch. 

 chem. Gesellsch., 12; Friedmann, Hofmeister's Beitrage, 4. 



5 His, Arch. f. exp. Path. u. Pharm., 22; Cohn, Zeitschr. f. physiol. Chem., 18; 

 Abderhalden and collaborators, ibid., 59. 



