12 



contents were dried at first very slowly in a water oven at a low tem- 

 perature, and the determination then continued as usual. 



The fat was determined by exti-acting- witii anhydrous ether the dried 

 samples remaining after the estimation of water. After twenty -four 

 hours' extraction the samples were removed and intimately ground 

 with ionited sand, then transferred again to the moisture tul)es, which 

 were loosely plugged with fat-free cotton to prevent an}" of the material 

 from being mechanicalh' carried into the flasks, and the extraction 

 continued for twelve hours. The usual Kjeldahl method was used for 

 the determination of the total nitrogen, special care being taken in 

 transferring the weighed meat to the Kjeldahl flask that none of the 

 material should adhere to the neck. In the distillation it was found 

 that pumice stone was preferable to granulated zinc, as experiments 

 made in this laboratory show that zinc reduces some forms of nitrogen 

 compounds which are always present in the ordinary alkali, and thus 

 introduces a slight error. The ash was determined as usual, but much 

 care was taken to heat the muffle very slowly and gradually at first so 

 as to prevent loss by sputtering. 



A careful and thorough test of this method for the direct determina- 

 tion of water, fat, nitrogen, and ash in the fresh substance of meats 

 has demonstrated its accuracy, and it may be considered of unques- 

 tionable advantage in these investigations or others of similar nature. 



PREPARATION AND ANALYSIS OF COLD-WATER EXTRACTS OF 



MEATS. 



As has already been said, in order to learn very much regarding the 

 chemistry of the cooking of meats it is necessary to distinguish much 

 more completely between their proximate principles than is done by 

 the ordinary methods of analysis. It was believed that in the meat 

 investigations here reported, as well as in future work, this could be 

 best accomplished by studying the cold-watei-'extracts of meats. After 

 much preliminary experimenting (which it is not necessary to describe 

 in this connection), a method of preparation and analysis of the cold- 

 water extracts of meats was elaborated and adopted. Since, so far 

 as the authors are aware, no method has been as 3'et proposed or 

 described for so complete an analysis of meats and other foods, the 

 method used is described here in detail. 



The uncooked or cooked meat was cut into small pieces and then 

 passed three times thrcTugh a small sausage mill or meat cutter. After 

 each grinding, the mill was cleaned and the meat thoroughlv mixed. 

 Three portions, of 30 to 33 grams each, were then weighed, the meat 

 being thoroughly mixed each time before an}^ of it was removed. 

 Each lot of 3U to 33 grams was distributed as equally as possible 

 between six small beakers. The samples were moistened with a little 



