lOl'O] FOODS — HUMAN NUTRITION. 165 



Tlio conflnsioii is (Irawn that the iiitroucii of chickt'ii skin is as well utilized 

 as that of meat, efr^^, ami milk. 



The extraction of " fat-soluble vitamin " from f-reen foods, T. li. Os- 

 UOKNK and L. H. Mkndkl (I'ror. tioe. JJxpt. liiol. und Med., 16 (191!)), No. 6, pp. 

 98, 99). — The authors state that they have obtained potent preparations of fat- 

 soluble vitamin from phint tissues, such a« spinach leaves and youns clover 

 by drying the material in a current of air at about GO" C, extracting with 

 U. S. P. ether, and evaporating the extract on starch. These preparations fe<l 

 in daily quantities equivalent to from 1 to 2 gm. of the drie<l plant promoted 

 recovery and renewal of growth in rats on diets deficient in fat-soluble vitamin. 



It is pointed out that these re^sults are contrary to those obtained by Mc- 

 C<»llum, Simmoiids, and Pitz, previously noted (E. S. R., 36, p. 61). 



Nutritive factors in plant tissues. — IV, Fat-soluble vitamin, T. B. Os- 

 isoKXE and L. B. Mendel (Jour. Biol. Chcm., Jfl (1920), No. 4, pp. 549-565, fig.'i. 

 11). — In continuation of the investigation previously noted (E. S. R., 42, p. 

 7n9), a study is reported of the potency of green vegetables, roots, etc., as 

 sources of fat-soluble vitamin as comparetl witli milk, fat, egg, etc Growing 

 rats were fed the various products apart from the basal food mixture in daily 

 do.ses of approximately 0.1 gm. of the substance air-drie<l at 60° C. or less and 

 ground to a powder. For purposes of comparison a series of rats was fed 

 0.1 gm. of butter fat daily instead of the dried vegetables, this amount repre- 

 senting from 1 to 1.4 per cent of the food mixture. 



With this amount of butter, good growth results were obtained for about 

 80 days. In comparison with this, two rats i-eceiving only 0.1 gm. of tomato 

 daily grew rapidly to exceptionally large adult size and showed no signs of 

 a failure of nutrition at the end of 804 days. It is thought that the very rapid 

 growth in this series of expeiiments may have been due in part to the richness 

 of the tomato in water-soluble vitamin and possibly also to its content of 

 antiscorbutic vitamin. Alfalfa, clover, timothy, and spinach in amounts of 

 0.1 gm. of the dried substance furnished relatively as much of this vitannn as 

 d<^s 0.1 gm. of butter fat. 



The growth results with carrots were not quite so satisfactory and with cab- 

 bage the least satisfactory. That the partial failure of cabbage was not due 

 to drying is considere<l satisfactorily proved from the positive results obtainetl 

 with the other dried vegetables. In the experiments with potatoes large quan- 

 tities were used (20 per cent of the food). The fact that two of the rats 

 grew to large size on the potato food indicated that the tuber can n<»t be en- 

 tirely devoid of fat-soluble vitamin. 



" The newer studies indicating the richness of many types of plant tissues 

 In those nutritive properties termed vitamins place the dietary importance of 

 the green vegetables in an entirely new light. It emphasizes their use to 

 supplement the refined foods of the modern food industry, which furnish 

 products rich in proteins, fats, and carbohydrates but in many cases com- 

 paratively deficient in the vitamins. The facts cited in the present investiga- 

 tion, along with others recently published, serve as an added reminder that 

 the fat-soluble vitamin need not be sought solely in foods known to be rich 

 In fats." 



Milk as a source of water-soluble vitamin. — 11, T. B. Osborne and L. B. 

 Mendel (Jour. Biol. Chevu, 41 (1920), No. 4, pp. 515-523, fig.'i. 4).— To determine 

 whether tht^ necessity of a relatively large quantity of milk as a source of 

 water-soluble vitamin in the feeding experiments with rats previously noted 

 (E. S. R., 80. p. .'570) might not be due to inferior (piality of the milk from a 

 vitaniiu staudpoiuc owing to tlie winter diet of tlie cows, a further series of 



