DIGESTION EXPERIMENTS WITH POULTRY. 325 



to the solution in order to determine the amount of alkali neces- 

 sary to dissolve all the uric acid, also the disappearance of the 

 white particles which settle to the bottom of the beaker indicated 

 complete solution. Usually it required one-half to three-fourths 

 of an hour heating on the steam bath with frequent stirring to 

 effect complete solution. After the white particles had all dis- 

 appeared and the solution remained alkaline it was passed 

 through a coarse linen filter into a 500 c. c. graduated flask, 

 washed thoroughly with hot water, squeezing out the filter two 

 or three times to facilitate washing, cooled, made up to the 

 mark and thoroughly mixed. This solution was then allowed 

 to settle until the fine particles which passed through the cloth 

 had settled out leaving a clear solution which could be drawn 

 off. It was planned to allow the flasks to settle over night and 

 the solutions were found to be clear the next morning. Fifty c. c. 

 portions, representing 2 grams of the feces, were taken, made 

 acid with HCl, evaporated on steam bath to 25 c. c. and set in 

 the refrigerator for 24 hours. Filtration was then carried out 

 without difficulty through a 597 S. & S. filter paper on a Buck- 

 ner's porcelain funnel 50 mm. in diameter, under pressure, 

 washed 3 times with cold water, then with absolute alcohol and 

 lastly 2 or 3 times with ether to remove any traces of fat re- 

 maining. The uric acid was thus collected on a very small 

 filter paper which was transferred to a beaker, boiled with 35 

 c. c. of distilled water and titrated with either i-io normal 

 piperidine or sodium hydrate. It was found necessary to com- 

 plete the end reaction with the solution as near the boiling point 

 as possible or concordant results could not be obtained. In all 

 cases 3 portions of 50 c. c. were taken out for the determina- 

 tion. The first titration being made somewhat roughly to find 

 the approximate end point. In carrying out the titration as 

 the end point was being reached the beaker was again put over 

 the flame and brought to the boiling point, then titrated to com- 

 pletion. To test the accuracy of the method pure uric acid was 

 added to feces that contained none. The average of the deter- 

 minations gave 98 per cent of the acid recovered. 



The piperidine and soda solutions were standardized with 

 uric acid which was purified by twice recrystallizing. and found 

 to be practically pure. The writer found that i-io normal 



