10-20 \ FOODS — HUMAN NUTRITION. 367 



loud licr Willi tlu' iTsiills of lour cxpt'i-iiuciils in llic iPi-cviiMis siinly, ;:;ivc an 

 avera;,'!' (•(n'lliciciit of tli.^csilliijii y of !)T per (h'IiI, the rankle lii'iii.i; from '.)\ t(j 

 KM) per cent. 



In two t'xpiM-inients in wliich tlie nitrogon output was deterniint'd, notic('al)le 

 iiH roascs in tin* fecal nilro^^on and in I lie vulnnic of the dry feces were ol)tained, 

 amount iui; to 54 and l'^'^ per cent for the former and 40 to 105 per cent for 

 the latter. 



Salep feedinj; did not result in glycosuria in one diabetic studied, nor did it 

 {irrest the production of |3-hydroxyliutyric acid in the other diabetic. IS'o 

 glycogen was stored in the livers of i-abbits fed on salep mannan. 



It is pointed out in conclusion that salep resembles inulin in its hydrolysis 

 by fecal bacleiia and in the readiness with wliich it disappears from tlu; ali- 

 mentary tract, as previously sliown by the work of Okey (E. S. 11., 41, p. 764), 

 but dilTers from it in not foiming gas so readily and in being less capable of 

 glycogen formation in rabbits. 



Vitamins, W. D. Halliburton (ticiGiitia, 27 {l'J20), No. 3, pp. ]'.).',-200).— 

 This is a brief discussion of tlie nature and signiticance of the vitamins, with 

 references to .some of the recent contributions to the subject. 



Fat-soluble vitamin. — VI, The extractability of tlie fat-soluble vitamin 

 from carrots, alfalfa, and yellow corn by fat solvents, H. SxEENnocK and 

 P. AV. IJoiTWEi.L {.Jour. Biol. Chcin., J,2 (1020), No. 1, pp. 131-152, flys. ^/).— In 

 continuation of the series of studies on the fat-soluble vitamin (E. S. II., 42, 

 p. 556), attempts have been made to concentrate this vitamin by extraction 

 with different solvents, including fats and fat solvents. The results, obtained 

 in the usual feeding experiments with rats, may be summarized as follows: 



The fat-soluble vitamin in carrots was not removed to any extent by satura- 

 tion with corn oil and extraction with ether, and apparently not at all by 

 similar satunition with lard. The vitamin was slightly soluble in ether, some- 

 what soluble in chloroform and carbon di.sulphid, and quite soluble in alcohol 

 and benzen<>, although none of the extracts was sufficiently concentrated for 

 practical purposes. 



"With alfalfa more satisfactory results were obtained with ether, benzene, and 

 alcohol, sufllcient fat-soluble vitamin being obtained in the ether extract to 

 permit satisfactory growth when fed at a level equivalent to 20 per cent of 

 alfalfa. 



To further concentrate the extract containing fat-.soluble vitamin, the authors 

 employed with the alcohol extract from alfalfa meal the method commonly used 

 for the separation of carotinoids. The extract was saponified with alcoholic 

 potassium hydroxid and the mixture extracted repeatedly with ether until the 

 yellow pigments were completely removed. The ether extracts after washing 

 with water to remove alkali and salts were evaporated on the water bath to 

 a small volume. This extract proved to be rich in fat-soluble vitamin. A fur- 

 ther concentration of the vitamin was brought about by taking up a similar 

 extract in a mixture of alcohol and petroleum ether and subjecting it to frac- 

 tional extraction. The petroleum-ether carotin fraction was found to contain 

 Jill abundance of the vitamin, while the alcohol xanthophyll fraction contained 

 little or none of it. The efficiency of this method of fractionation has been 

 demonstrated with different preparations. 



Tlie relative utilization by the animal organism of brewery yeast and 

 mineral yeast as determined by experiments with dogs and sheep, W. 

 VfW.TO tirc/(».s'c7(r. Brnu., 30 {1010), No. 7. pp. .'i3-'i'>; ahs. in Chcm. Ahs.. I'f 

 (1020), No. 10. p. 1.5GG). — A study of the conii)arative value of brewery yeast 

 and yeast grown in solutions of sugar and inorganic salts, as determined by 

 digestion experinu-nts with dogs and sheep, is reported. 



