752 URINE. 



and the conjugated group and this is brought about by boiling with 

 a dilute mineral acid. They are precipitated by basic lead acetate or 

 by basic lead acetate and ammonia. Most of the conjugated glucuronic 

 acids do not have a direct reducing action but are reducing after hydrolysis. 

 Certain of them, and to this group belong especially those acids of the 

 ester type, reduce copper oxide and certain other metallic oxides in alkaline 

 solution directly, and hence cause errors in the investigations of the 

 urine for sugar. The conjugated acids of the glucoside type rotate the 

 plane of polarized light to the left, while the glucuronic acid itself is dextro- 

 rotatory. The conjugated acids of the ester type, which as a rule are 

 less stable, rotate the ray of polarized light to the right. As the detection 

 of conjugated glucuronic acids is connected with the tests for sugar in 

 the urine, we will treat of this in connection with these tests. 



Organic combinations containing sulphur of unknown kind, which may 

 in small part consist of sulphocyanides, 0.04 (GSCHEIDLEN) to 0.11 p. m. 

 (I. MuNK), 1 cystine or bodies related to it, taurine derivatives, chon- 

 droitin-sulphuric acid and protein bodies, but in greater part are made up 

 of antoxyproteic acid, oxyproteic acid, alloxyproteic acid, and uroferric 

 acid, are found in human as well as in animal urines. The sulphur of 

 these mostly unknown combinations has been called " neutral," to dif- 

 ferentiate it from the " acid " sulphur of the sulphate and ethereal-sul- 

 phuric acid (SALKOWSKi 2 ). The neutral sulphur in normal urine is 

 13-24 per cent of the total sulphur. 3 In anaemia, cachetic conditions, 

 pulmonary tuberculosis and especially in carcinoma the quantity is 

 greatly increased (WEISS). In general it can be said that the quantity 

 is increased by an increased catabolism of protein and therefore an increase 

 in the neutral sulphur has been found in starvation (FR. MULLER), with 

 insufficient oxygen supply (REALE and BOERI, HARNACK and KLEINE) 

 and after chloroform narcosis (KAST and MESTER). After the introduc- 

 tion of free sulphur the quantity of neutral sulphur is increased, accord- 

 ing to PRESCH and YVON and to MAILLARD* The quantity of neutral 

 sulphur varies, according to BENEDICT, within rather narrow limits 

 and especially, according to FOLIN, it is dependent to a less degree than 

 the sulphate excretion upon the extent of the protein metabolism. The 

 relation between the neutral and acid sulphur depends in the first" place 



1 Gscheidlen, Pfliiger's Arch., 14; Munk, Virchow's Arch., 69. 



2 Ibid., 58, and Zeitschr. f. physiol. Chem., 9. 



Salkowski, 1. c.; Stadthagen, Virchow's Arch., 100; Le*pine, Compt. Rend., 91 

 and 97; Harnack and Kleine, Zeitschr. f. Biologic, 37; Mor. Weiss, Bioch. Zeitschr., 27. 



4 Weiss, 1. c.; Fr. Miiller, Berl. klin. Wochenschr., 1887; Reale and Boeri, Maly's 

 Jahresber., 24; Harnack and Kleine, 1. c.; Kast and Mester, Zeitschr. f. klin. Med., 

 18; Preach., Virchow's Arch., 119; Yvon, Arch, de Physiol. (5), 10; Maillard, Compt. 

 Rend., 152. 



