URINE 



291 



acid corresponds to .0017 grams of NH 3 or .0014 grams of N. 



Calculate the amount of ammonia nitrogen in the 24 hour 



specimen and also the per cent of the total nitrogen present 



as ammonia. 



Air 



FIG. 4. FOUN'S APPARATUS FOR ESTIMATING AMMONIA. 



A. Wash bottle containing acid. 



B. Tall aerometer cylinder containing urine. 



C. Bottle containing standard acid. 



D. Calcium chloride tube, loosely packed with cotton wool, to prevent any sodium 



carbonate being carried over into C. 



E. Folin's absorption tube, to bring the air into intimate contact with the acid. 



