CHAP. X.] HYDROPARACUMARIC ACID. 429 



3. By a process of decomposition, paroxyphenylacetic acid splits 

 up into carbon dioxide and parakresol, thus (Weyl): 



OH fOH 



CH 2 .COOH 08Ul tcH 3 + 



Para-oxyphenyl-acetic acid. Para-kresol. 



4. By a process of oxidation and subsequent decomposition (refer 

 to equations 5 and 6, p. 248), parakresol yields as products H 2 O, CO 2 

 and C 6 H 5 . OH or phenol. 



In addition to the above products, E. and H. Salkowski have 

 also found phenyl-propionic and phenyl-acetic acid amongst the 

 products of decomposition of certain albuminoid bodies. 



Hydroparacumaric acid, C 9 H 10 3 (HO . C 6 H 4 . CH 2 . CH 2 . CO . OH). 



(Para-oxyphenyl-propionic acid). 



This acid, besides being found amongst the products of the 

 decomposition of proteids, is also found in urine. 



_ .. When obtained by evaporation, the acid first of all 



Properties. ,, * * ., , . , , ,-, 



presents the appearance of an oil, which subsequently 



crystallises. When recrystallised from water, it forms small, colourless, 

 anhydrous, monoclinic crystals, which are readily soluble in water 

 (especially hot), alcohol and ether. The solubility of this acid in 

 water is greater than that of paroxyphenylacetic acid. Hydropara- 

 cumaric acid is sparingly soluble in benzol, but more soluble than 

 paroxyphenylacetic acid. The melting-point of the acid is 125 

 128 C. The zinc salt has the composition (C 9 H 9 3 ) 2 Zn -f 2H 2 and 

 crystallizes in pearly tables and leaflets, which are soluble in 130 parts 

 of water at ordinary temperatures. 



Reactions With solutions of ferric chloride it gives a fleeting, 



but distinct, blue colouration. When boiled with Millon's 

 reagent, the solution assumes a red colour and a red precipitate forms 1 . 

 It does not reduce Fehling's solution. 



Behaviour in When introduced into the organism hydropara- 

 organism. cumar i c ac id j s excreted in the urine in part as such, 

 and in part as phenol. 



1 Fliigge shewed that phenol exhibits Millon's reaction (P. C. Fliigge, 'Neue 

 Reaction auf Carbolsaure,' Zeitsch. f. anal. CJiemie, Vol. xi. (1872), p. 173. 0. Nasse 

 ('Ueber die aromatische Gruppe im Eiweissmoleciil,' fully abstracted in Maly's Jahres- 

 bericht, Vol. ix. (1880), pp. 2 4, shewed that Millon's reaction is not confined to 

 proteids and to tyrosin, but is a general reaction of all aromatic bodies in which a 

 hydroxyl group is connected with the benzol ring. 



