MAKKET COLD-STOEAGE CHICKENS. 65 



insoluble material than in the loss of the preformed water-soluble 

 nitrogen. The total extract of the muscle was made up to a definite 

 volume and neutralized to litmus paper with tenth-normal sodium 

 hydrate. 



Duplicate portions of 100 cc each were transferred to beakers, evap- 

 orated to very small bulk (about 10 cc), and transferred with the aid 

 of sulphuric acid to Kjeldahl flasks for the determination of total 

 nitrogen soluble in water. Duplicate portions of 350 cc were heated 

 on the water bath in order to determine the amount of coagulable 

 nitrogen present. It was found better for the complete separation of 

 the proteid to evaporate before filtering to about 100 cc. The coagu- 

 lum of the white meat separated more easily and in a much more com- 

 pact mass than did the coagulum of the dark meat. Both were diffi- 

 cult to wash free of proteid material. 



The coagulum and the filter paper were transferred to a Kjeldahl 

 flask for the determination of the amount of nitrogen. The filtrate 

 from the coagulum, having been considerably increased in volume 

 by the washings, was reduced to 100 cc. Fifty cubic centimeters 

 of this were taken for the determination of albumose, which was 

 made according to the method of Bomer. a Concentrate the liquid 

 to 30 cc and allow it to cool; add 1 cc of 50 per cent sulphuric acid, 

 saturate with zinc sulphate, warm on a water bath with stirring until 

 clear, and allow to stand 12 hours for the separation and deposition of 

 the precipitate. Filter cold and wash with a saturated solution of 

 zinc sulphate acidified with sulphuric acid. The determination of the 

 nitrogen is made as usual. 



In the other 50 cc portion of the filtrate from the coagulated pro- 

 teid the amido acids were determined according to the method of 

 Bigelow and Cook, 6 which, briefly stated, consists in the addition of 15. 

 grams of sodium chlorid to 50 cc of the amido acid containing extract, 

 chilling thoroughly in an ice box, then adding 30 cc of a 24 per cent 

 solution of tannic acid, making the volume up to 100 cc, and allowing 

 the whole to stand at the temperature of an ice box for 24 hours, after 

 which the precipitate is filtered off. The solution is kept cold mean- 

 while, and the nitrogen in 50 cc of the filtrate is determined according 

 to the usual Kjeldhal procedure, except that the addition of potas- 

 sium sulphate is unnecessary, because of the large amount of sodium 

 chlorid present, and care must be taken during the early part of the 

 oxidation that the escaping hydrochloric acid does not cause the mate- 

 rial to foam out of the flask. 



Since tannic acid invariably contains a certain amount of nitrogen, 

 a blank must be run with every experiment. 



Zts. anal. Chem., 1895, -84: 5G2. 

 & J. Amer. Chem. Soc., 1906,25: 1485. 

 49078 Bull. 11508 5 



