172 PHYSIOLOGICAL AND PATHOLOGICAL CHEMISTRY. 



phenaceturic acid, (C 6 H 5 CH 2 CO)NHCH 2 COOH, which appears 

 in the urine and is found constantly in horse-urine together 

 with hippuric acid. Phenyl-acetic acid has no characteristic 

 reactions. It gives the Liicke's reaction with nitric acid like 

 benzoic acid. The greater solubility of its zinc salt l and its 

 conduct in the organism distinguishes it from phenyl-propionic 

 acid. 



6. Phenyl-propionic Acid, Hydrocinnamic Acid, 

 C 6 H 5 CH 2 CH 2 COOH. 



Phenyl-propionic acid or hydrocinnamic acid crystallizes 

 in long fine needles melting at 48.5, and like phenyl-acetic 

 acid it yields benzoic acid on heating with potassium bichro- 

 mate and sulphuric acid. The solubilities of the acid are 

 about the same as those of phenyl-acetic acid; the zinc salt 

 is very difficultly soluble. In the organism phenyl-propionic 

 acid is oxidized to benzoic acid, which appears as hippuric 

 acid in the urine. Phenyl-propionic acid is normally the 

 first product in the formation of hippuric acid. 





 7. Paroxyphenyl-acetic Acid, Ce 



This substance crystallizes from water in prismatic, 

 extremely brittle needles, usually flat, which melt at 148. 

 It is fairly soluble in cold water, readily soluble in hot water, 

 alcohol, and ether, more difficultly soluble in benzene. The 

 aqueous solution gives with ferric chloride solution a faint 

 color, at first gray-violet, then dirty gray. It reacts positively 

 with Millon's reagent, and also gives a turbidity or precipi- 

 tate with bromine-water. When introduced into the organ- 

 ism it is for the most part excreted unchanged. A part is 

 converted into oxy phenaceturic acid. 



1 Zeitschr. f. physiol. Chemie, 10, 150. 



