1028 FOODS AND FOOD ADULTERANTS. 



which then escaped notice were flattened by the drug mill and easily 

 picked out of the sieve. 



The ground sample was bottled and used for analysis. 



WATER. 



In this powdered sample water was determined by drying at 100 in 

 a platinum dish. 



KTHElt EXTRACT. 



For the ether extract the sample used for water determination was 

 extracted with anhydrous ether in a Knorr extractor, the ether driven 

 off by a gentle heat, and the flask and extract dried to constant weight 

 in a steam -jacketed bath. This required about three hours. 



CRUDE FIBER. 



The ether-extracted material was transferred to a flask and treated 

 according to the method of the Association of Official Agricultural 

 Chemists 1 for fiber. The solutions of acid and alkali were each 2.50 per 

 cent. 



ALBUMINOIDS. 



Nitrogen was determined by the Kjeldahl method. 2 Albuminoids 

 were calculated by multiplying the per cent of nitrogen by the cus- 

 tomary factor, 6.25. 



DIGESTIBLE ALBUMINOIDS. 



Indigestible nitrogen was determined by Niebling's method, 3 viz: 

 One gram of sample was washed with ether and the washed residue 

 introduced into a flask, together with 50 cc of 0.2 per cent hydrochloric 

 acid. The mixture was brought to a boil, allowed to cool, exactly neu- 

 tralized, and 50 cc of Stutzer's pancreas solution added. The mixture 

 was then kept at a temperature between 37 and 40 for six hours, 

 shaking occasionally. At the end of this time it was cooled, allowed 

 to settle for a few minutes, poured through a 14 cm Munktell filter, and 

 the residue thoroughly washed with warm water (37 to 40). The 

 filter and residue were dried at 100, introduced into a flask, and treated 

 by the regular Kjeldahl process. The nitrogen thus found, multiplied 

 by 0.25, gave "indigestible albuminoids," and subtracting this number 

 from the total albuminoids found in the sample, left "digestible albu- 

 minoids." 



The pancreas solution was made up according to Stutzer's directions, 4 

 as follows: 



Free a cow's pancirn.s from Cut as f;ir as possible, mince, nil* up with s;ml, and 

 allow to stand in the air from twenty-four to thirty-six lion is. Mix the mans with lime 



1 Bull. 35, 215. 



2 Bull. 35,200. 



s Landw. Juhrb. 19, Mil; abs. Choin. Centrbl., 181K), 2, 116. 

 VerHsnchsst. 36, .321 ; aba. Chem. Centrbl., 181)0, 1, 176. 



