12 



the animal. In these cases the whole weight of hoofs was corrected for 

 the deficiency by using the average weight of one hoof for the weight 

 of each of the remaining hoofs. The hoofs were weighed and dried 

 in the steam oven and then left to assume their air-dry content of 

 moisture. They were then ground and submitted to analysis as 

 described below for the other parts. 



METHODS OF ANALYSIS USED. 



On the samples thus prepared the following determinations were 

 made: 



Water, fat, ash, total nitrogen, nitrogen insoluble in hot water, nitro- 

 gen soluble in hot water but precipitated by broinin, and lecithin. 



For the determination of MOISTURE and FAT 2-grain portions were 

 dried for six hours in a vacuum oven for the determination of water, 

 and the residues were extracted for sixteen hours with ether for deter- 

 mination of the fat. 



For TOTAL NITROGEN duplicate portions of one-half gram of the air- 

 dried sample were treated by the Gunning method. 



For INSOLUBLE PROTEID NITROGEN 1-gram portions were washed 

 with ether by decantation, using about 50 to 100 c. c. of ether for each 

 sample, and decanting the ether through niters which were afterwards 

 used to receive the portions of the sample insoluble in hot water. After 

 allowing the ether to evaporate the samples were next treated with hot 

 water, this washing being also by decantation, and the total amount of 

 water used being 300 to 400 c. c., the residues being brought on the 

 filter with the last portion of the water. The filters and residues were 

 then treated by the Gunning method. 



The filtrates from the insoluble portions of the meat were received 

 in Kjeldahl flasks and were used for the determination of the NITROGEN 

 PRECIPITATED BY BROMiN (GELATINOIDS). 1 After acidulation with two 

 or three drops of strong hydrocloric acid, about 2 c. c. of broinin were 

 added and the flasks vigorously shaken. If this quantity of bromin 

 was all taken up more was added and the shaking repeated until a 

 globule of about c. c. of bromin was left in the flask, and the liquid 

 above it was thoroughly saturated with bromin. The mixture was 

 then allowed to stand until the next morning, when the supernatant 

 liquor was passed through a filter and the residue in the flask washed 

 by decantation, the globule of undissolved bromin in the flask saturat- 

 ing the wash water with bromin, so that it was unnecessary to use 

 bromiu water for the washing. The filter containing the residue was 

 then returned to the same flask in which the precipitation had taken 

 place and treated by the Gunning method. 



The percentage of nitrogen in the form of FLESH BASES was found 

 by subtracting the sum of the numbers representing insoluble nitrogen 



1 See Appendix, page 79. 



