766 EXPEEIMEKT STATION RECORD. [Yol. 43 



tion previously noted (E. S. R., 40, p. 762), data are reported concerning the 

 antiscorbutic value of potatoes, raw and cooked, fresh and dried. The general 

 procedure and methods were the same as described in the first paper. Young 

 guinea pigs were fed a basal scurvy-producing diet of heated soy bean flour, 

 milk, yeast, paper pulp, calcium lactate, and salt, and to this was added 10 gra. 

 daily of fresh potatoes or its equivalent in the dried or cooked product. The 

 experimental results are presented in graphic form in the usual growth curves, 

 together with supplemental feeding curves indicating the amount of the basal 

 diet and of the supplemental diet (potatoes) consumed daily. 



A daily supplement of 10 gm. of raw white potato was sufficient to protect 

 the growing guinea pigs from scurvy for the duration of the experiment, 129 

 days. While the minimal protective amount of raw potato was not determined, 

 indications are that slightly less than 10 gm. daily is about the lower limit of 

 safety. Cooking the potatoes in water at 100° C. for 15 minutes caused only 

 a slight reduction in antiscorbutic value, while cooking for an hour at the same 

 temperature reduced the vitamin content to such an extent that the disease 

 could not be arrested by feeding 15 gm. daily of the product. Scurvy was 

 checked in two animals by feeding 10 gm. of potatoes cooked in 1 cc. of 0.5 

 per cent citric acid for 1 hour. 



With potatoes dried at 35 to 40° death from scurvy was slightly delayed by an 

 amount (2.5 gm. ) equivalent to 10 gm. of the fresh product, while with double 

 the amount life was prolonged still fui'ther. One out of four animals on a 

 daily dose of 2.5 gm. dried at 55 to 60°, and one out of three animals on the 

 same amount dried at 75 to 80°. showed signs of scurvy at death. On heating 

 at 100° for 1 hour the products dried at these temperatures, no protection was 

 secured in any case. 



Potatoes baked in the skins for from 45 to 55 minutes at 204° and then 

 scooped out and dried at 35 to 40° protected against scurvy in 2.5 gm. daily 

 portions. The potato skins had no protective action. Potatoes steamed for 4 

 minutes, dried at 55 to 60° and cooked for 15 minutes at 100°, offered no pro- 

 tection even when the dose was doubled. Potatoes soaked over night in dilute 

 acetic acid, dried at 55 to 60°, and then cooked for 15 minutes at 100° gave no 

 protection. Similar results were obtained with a like treatment with dilute 

 hydrochloric acid. 



In discussing these results, the authors suggest the possibility that the factors 

 involved in the destruction of the antiscorbutic vitamin are not only the degree 

 of heat and the duration of the heating but also the enzym content and the 

 reaction of the food being dried. By employing a high temperature for a short 

 time, as in the case of baked potatoes, the enzyras are destroyed, while at any 

 temperature below 80° the enzyms are still functioning and pi'obably play an 

 important role in the destruction of the antiscorbutic vitamin. 



Influence of diet on the antiscorbutic potency of milk, E. B. Hakt, H. 

 Steenbock, and N. R. Ellis {Jour. Biol. Chem., .',2 (1920), No. 3, pp. 383-396, 

 pi. 1, figs. 15). — This paper reports the result of an investigation of the dietary 

 relation to the antiscorbutic vitamin concentration in cow's milk. 



The varieties of milk tested included dry feed milk, obtained from a herd of 

 18 cows which had never been fed any fresh vegetable tissues but only air- 

 dried roughages and grains ; summer pasture milk from cows which during 

 part of the day grazed on a timothy, blue grass, clover pasture ; and winter 

 produced milk from cows fed on dried grains and hays, supplemented in one 

 case by a corn silage made from corn that had well matured and partly dried 

 but had not been frozen, and in another case by a small amount of silage and 

 a considerable, amount of hybrid sugar mangels. Each variety of milk was 

 tested for its antiscorbutic vitamin content by feeding it to guinea pigs in 



