‡ Temperature of the substance itself and length of time it remained at this point.

(1) Cooper, E. A., J. Hyg., 1012, si, 448.

(2) Steenbock, H., J. Biol. Ghem. 1017, xrix, p. xxvii.

(3) Griins, Geneesk, Tijdschr. v. Ned. Ind., 1901, xli, 30.

(4) Holst; H., J. Hyg., 1007, vii, 610.

(5) Chick, H and Hume, E. M., J. Roy. Army Med. Corps., 1017. xxix, 121.

(6) Chick, H., and Hume. E. M., Proc. Roy. Soo. London, Series B. 1019, xc, 44.

(7) Eykman, C, Arch, Hyg., 1906; lviii, 150. (8) Vedder, E.B, J. Hyg., 1918, xvii. 1.

(9) Weill, B., Mouriquand, G., and Michel, P., Compt rend. Soo. biol. 1916, lxxix. 189. (10) Weill, &, and Mouriquand, G., Compt. rend. Soo. biol., 1915, Ixxviii, 649.

‡ Temperature of the substance itself and length of time it remained at this point.

(3) Grijns, Geneesk. Tijdschr. v. Ned. Ind., 1901, xli, 30. (4) Hofit, H., J. Hyg., 1907, vii, 619. (5) Chick, H., and Hume, B. M., J. Roy. Army Med. Corps., 1917, xxix, 121. (6) Chick, H., andHume E. M. Proc. Roy. Soc. London, Series B, 1919, xc, 44. (7) Bykman, C, Arch. Hyg.. 1906, Iviii, 150.

(11) Schaumann, H., Arch. Scniffs-u. Tropenhyg.. 1910, suppl., xiv, 64.

(12) Voegtlin, C, and Lake, G. C, Am. J. Physiol., 1918-19, xlvii, 558.

Growth-Promoting Vitamin (Water-Soluble B)

† Placed in cans, then immersed in water, and heated at 100° for 2 hrs.

(13) Osborne, T. B., and Mendel, L. B., J. Biol. Chem. 1918, xxxiv, 17.

(14) Osborne, T. B., and Mendel, L. B., Carnegie Inst of Washington, Pub. 156, pts. i and ii, 1911.

(15) McCoflum, B. V.. and Davis, M.. J. Biol. Chem. 1915, xxiii, 247.

(16) Drummond, J. C., Biochem. J. 1917, xi, 255.

(17) McCoDum, B. V., and Simmoads, N., J. Biol. Chem. 1918, xxxiii, 55.

(18) Daniels, A. L. and McClurg, N. L, J. Biol. Chem. 1919, xxxvii, 201.

(19) Denton, M. C, and Kohman, B., J. Biol. Chem. 1918. xxxvi 249.

(20) Osborne, T. B. Wakeman, A., and Ferry. B. L., J. Biol.Cnem. 1919, xxxix, 35.

(21) Osborne, T. B., and Mendel, L. B., J. Biol. Chem. 1917, xxxii, 309.

(22) Hawk, P. B., Flshback, H. R, and Bergeim, O., Am. J. Physiol, xlviii 211.

(12) Voegtlin, C, and Lake, G. C, Am. J. Physiol. 1918-19, xlvii, 558.

(15) McColium, B. V., and Davis, M., J. Biol. Chem. 1915, xxiii, 247.

(16) Drummond, J. C, Biochem. J., 1917, xi, 255.

(17) McColium, E V., and Simmonds, N. J. Biol. Chem. 1918, xxxiii. 55.

(18) Daniels, A. L., and McClurg, N. L, J. Biol. Chem. 1919, xxxvii, 201.

(22) Cohen, B., and Mendel, L. B., J. Biol. Chem. 1918, xxxv, 425.

(23) McColium, E. V., Simmonds, N., and Pitz, W., J. Biol. Chem. 1917, xxix, 521. (25) Williams, R. J., J. Biol. Chem., 1919, xxxviii, 465.

Emmett and Luros (1. c.) compare the effect of the same foodstuff on polyneuritis in pigeons and on the rate of growth of rats, using umnilled rice as the exclusive diet for pigeons37 and the basal diet, supplemented with lactalbumin salt mixture, butter-fat, and lard for rats. They obtained evidence that the antineuritic vitamin (tested on pigeons) in unmilled rice is stable to heat at 120° C. and 15 pounds pressure for one hour. It is partially altered by heating in the air oven at 120° C. for two hours, and totally destroyed at 120° C. and 15 pounds pressure in two and six hours. The vitamin in extracts is more easily altered by heat. The water-soluble B vitamin (tested on rats) in unmilled rice appears to be stable to heat at these same temperatures, that is, it is not distinctly or totally broken down. Whether this vitamin was slightly destroyed could not be definitely ascertained due to the lack of quantitative methods.

37See Gibson and Conccpcion, Phil. J. Sci. 9, 119, 1914.

Emmett and Stockholm38 endeavored to obtain further evidence on this point by using the Williams39 method as a test for the growth-promoting B. Tests were made with unmilled rice, unheated and heated in the autoclave for 1, 2 and 6 hours respectively at 120° C. and 15 pounds pressure. They found no indication that the factor which stimulated the growth of yeast cells was altered in the least by heating. When the heated rice was tested on polyneuritic pigeons it was found to be entirely lacking in antineuritic power. Normal rats fed on this heated rice gained in weight, although the gain on the rice which had been autoclaved six hours was only moderate. It is noteworthy, however, that rats which have been brought to a low nutritive plane through lack of B persistently lost weight on extracts of heated rice (autoclaved for two hours), while responding promptly to dosage with extract of unheated rice. This suggests the possibility that the yeast-stimulant is not identical with growth-promoting B.

Much work remains to be done before this point can be definitely settled. Since, however, it would seem wise to keep in mind the possibility of the existence of two vitamins of the B type, we have endeavored, so far as possible, to indicate whether it is the antineuritic or the growth-promoting power of B which is taken into consideration.

From autolysed yeast Funk and Dubin39 were able to separate one substance active for yeast and another which was active for rats and pigeons, showing that yeast requires for growth a different substance than that needed by animals. They regard the yeast-active substance as a new vitamin or a cleavage product of vitamin B and provisionally call this substance Vitamin D. An almost quantitative separation of this vitamin from autolysed yeast may be made by two successive shakings with 100 grams of fuller's earth or of norit, per litre. The fuller's earth and norit are decomposed by baryta and glacial acetic acid respectively, according to the method of Seidell and of Eddy and co-workers. Norit extracted with baryta does not yield an active substance. Vitamin D, according to Funk and Dubin, appears to be a definite and specific substance stimulating the growth of yeast. Although vitamin D has been obtained from vitamin B, as far as animal experiments have shown, the reverse is not true. If therefore most animal tests conducted up to the present time were carried out, with a mixture of vitamins B and D it will be desirable to repeat these tests with the separate vitamins.40

38 Emmett and Stockholm, J. Biol. Ghem. 48, 287, 1020. 39 J. Biol. Chem. 48,487, 1921.

40 See also Emmett and Stockholm, J. Biol. Chem. 43, 287, 1020.

The anti-beriberi vitamin and the separation of vitamin D are discussed by Funk (J. Ind. Eng. Chem. 1921, 1110).