466 EXPERIMENT STATION RECORD. [Vol.41 



port of a study of the growth-promoting property for rats of rations containing 

 lactalbumin as the sole protein and differing only in respect to the kind of 

 synthetic protein-free milk used. From the results obtained the following con- 

 clusions were drawn : 



" Lactalbumin is a complete protein in the sense that it does not lack any of 

 the nitrogenous cleavage products essential for gi-owth. It can supplement a 

 deficient growth-promoting jirotein (corn gluten) and, incorporated as the sole 

 protein in a ration containing lactose, it produces a normal rate of growth when 

 present to the extent of only 10 per cent. Lactalbumin is a protein which 

 either is sensitive to certain toxic substances, and under these conditions 

 growth is retarded unless adequate adjustment is made in the diet ; or it is a 

 protein which does not appear to be able to ab.sorb what we tentatively designate 

 as a vitamin (other than water-soluble B). 



" Lactose seems to be the essential constituent in the protein-free milk that 

 contributes the accessory which makes an otherwise incomplete lactalbumin 

 diet bring about normal growth in rats. Lactose, when added to a lactalbumin 

 diet, either may have the physiological property of overcoming the toxicity that 

 inhibits growth taking place, or else it may carry a water-soluble vitamin (other 

 than water-soluble B) wliich appears to be essential to growth." 



The stability of lactalbumin toward heat, A. D. Emmett and G. O. Lueos 

 (Jour. Biol. Chem., 38 {1919), No. 2, pp. 257-265, figs. 7').— Continuing the in- 

 vestigations on the growth-promoting value of lactalbumin noted above, a study 

 is reported of the effect of heat upon the nutritive value of lactalbumin as 

 determined by feeding experiments with rats on a basal diet of protein- free . 

 milk 28 per cent ; butter fat 5, IS, or 28 per cent ; lard none or 10 per cent ; 

 and starch to make up the balance after adding the protein (10 per cent lactal- 

 bumin subjected to different temperatures up to 6 hours in the autoclave at 

 15 lbs. pressure). 



The data obtained indicate that " high temperatures do not influence the 

 growth-promoting value of lactalbumin when dried in vacuo at 55°, or heated 

 in an air oven at 90 to 100° for IG hours, or in an autoclave at 15 lbs. pressure 

 for 2 to 6 hours, respectively; that the amount of butter fat, whether 5, IS, or 

 28 per cent, when used with a 2-hour-autoclaved lactalbumin, has no influence 

 on the rate of growth ; that heated lactalbumin is not toxic for young growing 

 rats." 



The authors correlate these results with the somewhat conflicting results 

 obtained by McCollum and Davis (E. S. R., 34, p. 368), Funk and Macallum 

 (E. S. R., 36, p. 160), and Hogan (E. S. R., 37, p. 467) with heated casein, 

 on the hji^othesis noted in their previous communication that there is a vitamin 

 factor involved which is different from water-soluble B at least in being un- 

 stable toward heat. 



In the diets in which satisfactory results were obtained with heated casein 

 or lactalbumin. this vitamin is thought to be furnished probably by the lactose 

 of the protein-free milk. 



Distribution of the antineuritic vitamin in the wheat and corn kernel. — A 

 contribution to the biology of the antineuritic vitamin, C. Voegtlin and C. N. 

 Myers {Amer. Jour. Physiol, ^8 {1919), No. 4, pp. 50^-511, figs. ^).— The investi- 

 gation reported was conducted on adult pigeons, series of which were fed on 

 the following mixtures: Degerminated corn (corn kernel from which the germ 

 had been removed) ; 90 per cent degerminated corn, 5 per cent purified casein, 

 and 5 per cent salt mixture ; 85 per cent degerminated corn, 5 per cent purified 

 casein, 5 per cent salt mixture, and 5 per cent butter fat; whole corn; and 

 degerminated wheat. 



