CHEMICAL BASIS OF Till: ANIMAL BODY. l-j:, 



formation of this acid is undoubtedly due to tin- primary produc- 

 tion of phenol l.y putrefactive processes from proteids, and the 

 subsequent colligation of this phenol with sulphuric acid, very 

 little is known of the seat or mode of this union. It has not 

 definitely connected, if at all, with any distinctly synthetic 

 activity of tin- kidney. 1 



Since, as lias been said, phenol does not exist in the free state 

 in urine, its detection necessitates the decomposition of its com- 

 pound, vix. the phenylsulphate of potassium. This is best l-nui-lit 

 about by distilling the urine (200 c.c.) with strong hydrochloric 

 acid (40 c.c.) or 5 p.c. of sulphuric acid until about 150 c.c. of 

 distillate has passed over. The distillate contains free phenol, 

 which is tested for qualitatively by the reactions described below, 

 and estimated quantitatively by the formation of a compound 

 with bromine, tribromphenol, C 6 H 2 Br 8 .OH. 2 



J'/n /in/ reactions (i). A violet-blue colouration on the addition 

 of neutral solutions of perchloride of iron. This colour is similar 

 to that yielded by salicylic acid, but the absorption spectra of the 

 two are stated to be different. 3 It is destroyed by excess of the 

 reagent and is also not obtained in presence of acids and alkalis 

 alcohol. 4 (ii) When a solution of phenol is mixed with 

 one quarter of its bulk of ammonia and a few drops of chloride 

 of lime solution (1 to 20 of water) and gently warmed it yields a 

 blue colouration. 5 (iii) When boiled with Milloifs reagent a 

 marked and persistent pink or red colour similar to that yielded 

 by tyrosin is obtained. 6 (iv) Mere traces of phenol give a yel- 

 h crystalline precipitate on the addition of bromine water. 

 This reaction is used as stated above for the quantitative estima- 

 tion of phenol. Of these reactions (iii) and (iv) are the most 

 delicate, (v) On the addition of furfurol (Cjl^Oj, aldehyde of 

 pyromucic acid) solution ('5 p.c.) and strong suliihuric acid, phenol 

 yields a brilliant red colour which finally turns to blue. 7 



6, Kresol. r,,H 4 . OH. CH 3 . M.-thylphenol. 



This lioniologue of phenol exists in three isomeric forms, ortho-, 

 . and metakresol. It i^ now known that the phenols which 

 may be obtained by the distillation of urine with acids consist 

 preponderatingly of parakrel, accompanied in some cases by 

 orthokresol and possibly (?) by metakresol in minute amounts. 

 Like phenol it is not found free in urine, but as kresylsulphuric 



i Christian! n. B.iinnami. '/J. t. /.*//../. Chfm. Bd. II. (1878), S. 350. See aliw 

 i Bd. J 



itri.a 



uk.-nh.-ri,'. Vrrh.o.dl. d /.A,,.*,/.-./..,/. <; f *,ll. : \Viir-Jntn,, B.I. xvitl (1884), 



II. *,,,.. I.i.-l.i K V Annul. B.I. la (l*7f, > I'-l 



irokl, I'll... I'-l v rl-7-.'l. S. 353. 



1'lu / 173 See also Alnufo, Ibid., Bd 



xvii. (i-:- . s Ki7 



.rmi!./.ky. /,t / i>fiiiiol. Chem. Bd. xil. (1888), Sn 355. 



