954 EXPERIMENT STATION RECORD. 



lion for 2 hours loiifjer gave higher results, tiir average difference being about 1 per 

 f(Mit of tlu' amount of nitrogen present. Wlicn tiie sample wiis digested with both 

 nicnurv and iiotassiniu sulphate slightly higher results were obtained and the time 

 re(iuin'd for digestion was reduced, though it was still necessary to continue the 

 boiling beyond the point at which the solution became colorless. The results were 

 not ajipreciably affected l)y the addition of copper sulj)hate or ])otassium permanga- 

 nate to the reagents mentioned. 



The following procedure is recommended for the determination of nitrogen exist- 

 ing in the form of proteids and related compounds: "Treat the sample with 20 cc. 

 of concentrated sulphuric- acid and 0.7 to 1 gm. of mercury, heat gently until frothing 

 subsides, and then add 10 to 15 gm. of potassium sulphate and boil. Usually the 

 solution becomes colorless in less than 30 minutes, and the transformation of nitrogen 

 into ammonium sulphate is complete within an hour." A further study with organic 

 compounds of known structure is contemiilated. 



Method for the determ^ination of proteids in plants, L. Beulaygce {Contpt. 

 litnil. Antd. Sci. l\iri.s, 138 {lf)04), ^o. 11, pp. 701-703).— 1:\\q method described ia 

 believed to be more accurate and rapid than that of Stutzer and Hirschler. 



The rapid determination of fat by means of carbon tetrachlorid, A. P. 

 Bryant {Jour. Amer. Chem. Soc, 26 {1904), No. 5, pp. 568-573, fig. i).— A compari- 

 son of carbon tetrachlorid with more common reagents for the extraction of fat led 

 the author to the conclusion that the tetrachlorid is very satisfactory for this pur- 

 pose, especially in the commercial analysis of foods and feeding stuffs. It was found 

 very rapid in its action, "two hours apparently sufficing for complete extraction in 

 all cases. It is uninflammable, thus reducing the danger of explosion and fire to a 

 minimum, [and] it is inexpensive." 



From the figures showing the results of comparative tests the following are quoted: 

 In four of the samples of vegetable origin the amount of ether extract was 0.12, 0.14, 

 0.17, and 4.06 percent, respectively, the carbon tetrachlorid extract in corresponding 

 samples being 0.12, 0.15, 0.17, and 4.06 per cent, respectively. Practically as close 

 agreement was found in the case of other samples. As compared with carbon bisul- 

 phid, the carbon tetrachlorid extract in several samples of vegetable origin was 10.7, 

 11, and 11 percent, respectively, and the carbon bisuljihid extract was 10.1, 10.8, 

 and 10.7 per cent, respectively. In the ca.se of air-dried pork the amount of ether 

 extract was 71.3 per cent and the carbon tetrachlorid extract 72.6 per cent. 



In extracting fat with carlion tetrachlorid the Knorr extraction apparatus was 

 used, the flasks Ijeing heated on a water bath with live steam and protected with 

 copper shields in the form of half cones, in order to, prevent condensation of the 

 carbon tetrachlorid in the lower part of the apparatus. 



Observations on the composition of potato starch, A. Feknbacii {Compt. 

 Rend. Acad. Sci. Paris, 138 {1904), No. 7, pp. 4~S-430). 



Concerning- the acid content of different sorts of flour and other analytical 

 data, A. Fachinato {Gaz. Chim. ItaL, Si! {1903), II, pp. 54-3-555; cd>s. in Ztschr. 

 Untersuch. Nahr. \i. Genussmtl., 7 {1904), No. 5, p. 299). — In the author's opinion, 

 the estimation of the acid present in an alcoholic extract of flour is especially useful 

 as a means of judging of its quality. Phenolphthalein is used as an indicator. 



Note on the hydrolysis of edestin, E. Abderiialden {ZtscJir. Physiol. Chem., 

 40 {1903), No. 3-4, pp. 249, 250). — A note supplementing the investigation previously 

 reported (E. S. K, 14, p. 1044). 



The examination of meat, yeast, and other extracts for xanthin bodies. 

 II, The xanthin bodies of yeast extracts, K. Micro {Ztschr. Untersuch. Nahr. 

 u. Genus.vntl., 7 {1904), No. 5, pj). 257-270). — Analytical methods are described and 

 results reported. 



The oxidation of g-elatin with permanganates, G. Zickgraf {Ztschr. Physiol. 

 Chem., 41 {1904), No. 3, pp. 259-272). — Oxidizing gelatin with different permanga- 



