27 



tion — or dilute cupric sulphate and caustic potash and 

 heat — there should occur a ppt. which at first may be 

 white and after a time turning green or reddish. 



(Fehling's Solution is put up in two bottles; one 

 labeled A, the other B. In making tests, take equal parts 

 of A and B and add the substance to be tested. See for- 

 mula in appendix.) 



Schiff's Test. Dissolve a little uric acid in a small 

 quantity of 10% sodium carbonate solution. "With a glass- 

 rod, place a drop of silver nitrate solution on filter paper 

 and then a drop of the uric acid solution so that the two 

 drops partially overlap. A dark brown or black spot of 

 reducing silver appears. 

 Hippuric Acid, (C9H9NO3), is found especially in the 

 urine of the herbivora, as the horse, ox, etc. In the urine of 

 carnivora, and especially in that of man, it exists in but very 

 minute quantity, usually abouV 0.5 to 1 gram being excrete^ in ■'<■ 



2i hours. -It dissolves readily in hot alcoliQl but is spajringly s^-' JtA J 

 uble in water. It occurs in man after the ingestion of certain ' 



vegetables, such as asparagus,, plums, pears, and apples with ^ , 

 their skins; a ptirely vegetable diet and from the use of benzoic "> 



acid, cinnamic acid, essence of bitter almonds, quinine, and an- 

 alogous bodies. Hippuric acid normally 'seems to be derived 

 chiefly from the husks or cuticular structui^ps of the food. 



Pathologically hi-p-pnric acid isincreased in diabetes, chorea ; 

 jaundice and other liver complaints ; and in the acid urine of 



.A 



Fig;, 6. 

 Crystals of Hippurio Acid. 



Fig. 7. 

 Various forms of Hippuric Acid 

 with triple phosphates. 



