194 PHENOL. 



be obtained by simple distillation. In accordance with this it is 

 formed in not inconsiderable quantity in the alimentary canal, 

 more especially when putrefactive processes in its contents are 

 increased either pathologically or as the result of experimental 

 interference. 1 On the phenol thus formed a small proportion is 

 passed out in the faeces, 2 the larger part however is excreted in 

 the urine as an ethereal salt of sulphuric acid, viz. phenylsul- 

 phate of potassium. The latter is typical of an extensive series 

 of similar ethereal sulphates which make their appearance in 

 urine after the ingestion of aromatic substances. 



Their nature and constitution was first definitely ascertained by 

 Bauinann, 3 although it had previously been shown that phenol, 

 .even after it has been administered as such, does not exist in the 

 free state in urine but may be set free by distillation with a 

 mineral acid. 4 



Phenyl-sulphuric acid. 5 C 6 H 6 . O . S0 2 OH. Apart from its 

 abundant presence in urine as an alkaline salt after the admin- 

 istration of phenol this compound occurs normally in small 

 quantities in most urines, more particularly in those of herbivora, 

 since in these animals the conditions for its formation are espe- 

 cially provided by the preponderance of aromatic compounds in 

 their food and the more marked activity of putrefactive changes 

 in their alimentary canal. The total sulphates in urine consist 

 therefore partly of this ethereal sulphate (together with the 

 similar compounds of kresol, indol, and skatol, see below) and of 

 ordinary sulphates. The relative amounts of the sulphuric acid 

 contained in these two forms is ascertained by acidulating with 

 acetic acid and adding barium chloride, by which the sulphuric 

 acid present as ordinary sulphates is precipitated as barium sul- 

 phate. The filtrate from this is now boiled with hydrochloric 

 acid, by whose action the ethereal sulphates are decomposed, 

 yielding phenol and sulphuric acid, which again forms barium 

 sulphate ; from this the amount of the ethereal salts of sulphuric 

 acid may be at once determined. 6 While the probable mode of 



1 E. Salkowski, Ber. d. d. chem. Gesell. 1876, S. 1595. Ibid. 1877, S. 842. Cen- 

 tralb. f. d. Med. Wiss. 1876, S. 818. Arch. f. Pht/siol. Jahrg. 1877, S. 476. Brieger, 

 Zt.f.'phi/siol. Chem. Bd. n, (1878), S- 241. G. Hoppe-Seyler, Ibid. Bd. xn. (1888), S. 1. 



2 Brieger, Ber. d. d. chem. Gesell. 1877, S. 1027. Jn, f. prakt. Chem. Bd. xvn. 

 (1878), S. 134. 



3 Pfliiger's Arch. Bd, xin. (1876), S. 285. Ber. d. d. chem. Gesell. 1876, S. 55. 

 Baumann uud Herter, Zt. f. phi/siol. Chem. Bd. i. (1877), S 244. See also 

 Baumann, Ibid. Bd. n. (1878), S. 335, Bd. x. (1886), S. 123. For a list of 

 substances which when administered leave the body as ethereal sulphates, see 

 Hermann's Hdbch. d. Physiol. Bd. v. Th. 1, S. 508. 



4 Buliginsky, Hoppe-Seyler's Med. chem. Unters. Hft. 2, 1866, S. 234. Hoppe- 

 Seyler, Pfluger's Arch. Bd. v. (1872), S. 470. 



5 Not to be confounded with phenolsulphonic acid, C 6 H 4 (OH). SO 2 OH. 



6 For the accurate separation of the ethereal sulphates which usually occur 

 mixed in urine, some special works should be consulted, such as Neubauer u. Vogel, 

 Analyse des Harns, or Salkowski n. Leube, Die Lehre vom ffarn. Cf. Baumann, Zt 

 f.physiol. Chem. Bd. i. (1876), S. 70, Ibid. Bd. vi. (1882), S. 183. 



