130 



AaBC D 



HIPPURIC ACID. 

 Eb F G 



HIT 



Spectrum of pure alkaline hematine. 



5. Dissolve hematine in water with a little caustic 

 potash. To a solution of ferrous sulphate add tartaric 

 acid and then ammonia till alkaline. Pour a little of 

 the clear mixture into the hematine solution, and 

 examine the spectrum. It will show two bands. 

 Shaking with air will restore the former spectrum. 



AaBC 



Spectrum of reduced hematine. 



Hippuric Acid, C 9 H 9 N0 3 . 1. Evaporate the fresh 

 urine of horses or cows which have been kept in the 

 stable for a day or two previous to ^ or -g- of its 

 original volume, and add an excess of hydrochloric 

 acid. After standing the hippuric acid is thrown 

 down as a yellowish-brown precipitate. 



2. Filter or decant the liquid and purify the crude 

 hippuric acid as follows : Boil with milk of lime and 

 filter ; precipitate the nitrate with sodium carbonate, 

 boil, filter, add solution of chloride of lime, filter, 

 add an excess of hydrochloric acid. The hippuric acid 

 will finally be precipitated in a colourless condition. 



