488 PHENOL, KRESOL, PYROCATECHIN, AND SKATOL. 



Phenol, C 6 H 6 O, carbolic acid, occurs, according to Baumann, like- 

 wise united with sulphuric acid, as phenol-sulphuric acid, C 6 H 5 OSO 3 H, 

 which is found in the urine in combination with potassium. It is 

 present in large amount in horses' urine. 



Phenol results from the decomposition of albuminates through pancreatic di- 

 gestion, and especially through putrefactive processes. The mother-substance is 

 tyrosin. - The formation of phenol-sulphuric acid is, therefore, entirely analogous 

 to the formation of indican. Phenol, as well as kresol, is increased in the urine in 

 the presence of infectious and suppurative diseases, as well as of diabetes, If 

 phenol is employed internally or externally, the amount of phenol-sulphuric acid 

 in the urine increases greatly. Therefore, sulphuric acid must unite with it. 

 For this reason, alkaline sulphate is decomposed in the body, so that it may be 

 entirely wanting in the urine. Living muscular structure or liver, digested for 

 seven hours in a current of air with blood, with addition of phenol and sodium 

 sulphate, forms phenol-sulphuric acid. Likewise, under these circumstances, 

 pyrocatechin forms ether-sulphuric acid. 



The dark discoloration of the urine often observed in human beings after 

 the internal or external employment of phenol depends upon oxidation of the 

 phenol into hydroquinone (orthodioxybenzol, C 6 H 6 O 2 ), which appears in the urine 

 in large part as ether-sulphuric acid. 



Parakresol (hydroxyltoluol, C 7 H 8 O) is present in larger amount 

 than phenol, together with the isomers, orthokresol and metakresol, 

 the latter in traces; also these, combined with sulphuric acid as kresol- 

 sulphuric acids. 



For the demonstration of phenol, and also of kresol, 150 cu. cm. of urine 

 are distilled with dilute sulphuric acid. The distillate yields, with bromin-water, 

 a precipitate of tribrom-phenol, which soon crystallizes; as well as a red color with 

 Millon's reagent. The hydroxylbenzols pyrocatechin and hydroquinone are 

 given off after protracted heating of urine to which hydrochloric acid is added. 

 Resorcin, which is isomeric with hydroquinone, leaves the body in the urine as 

 ether-sulphuric acid when ingested. Toluol and naphthalin react in a similar 

 manner. When benzol is administered, it is first oxidized into phenol. 



Pyrocatechin, C 6 H 6 O 2 , metadihydroxylbenzol, is formed, together 

 with hydroquinone, from phenol; and it is likewise isomeric with hy- 

 droquinone. In an analogous manner to indol and phenol, it is united 

 with sulphuric acid. Infinitesimal amounts occur normally. It has 

 been observed in larger amount by Ebstein and Miiller in the urine of a 

 dyspeptic child. It can be recognized by the dark discoloration of the 

 urine that results from putrefaction. 



Possibly pyrocatechin is formed in the body from decomposed carbohydrates, 

 from which Hoppe-Seyler observed it to develop by heating with water under 

 high pressure, as well as by treatment with alkalies. 



Skatol, which appears in crystalline form in the presence of in- 

 testinal putrefaction, likewise appears in the urine as an ethereal sul- 

 phate. Brieger found potassium skatoxyl-sulphate after feeding dogs 

 with skatol. 



Demonstration. -The skatol-combination can be recognized by addition of 

 dilute nitric acid, in consequence of which a violet color results; or of fuming 

 nitric acid, in consequence of which red flakes are precipitated. Its amount varies 

 with the same causes as does that of indican. 



Also hydroparacumaric acid and paraoxyphenylacetic acid, which belong to the 

 aromatic oxyacids, are encountered in the urine in increased amount, together 

 with a large amount of indican, in the presence of urticaria, acne, and senile pruri- 

 tus, as signs of increased intestinal putrefaction. The first is a putrefactive 

 product of meat, while the second has been obtained by E. and G. Salkowski 

 from putrid albumin. 



Demonstration. If the urine, to which a mineral acid has been added, is 



