610 



SCIENCE 



[Vol. LVI, No. 1456 



P. KoHMAN. We hear much about the destruc- 

 tion of vitamins by the action of heat and oxida- 

 tion. Vitamin A is said to be especially sensitive 

 to oxidation and vitamin C to both heat and 

 oxidation. But Tvith the exception of a very few 

 instances, the experiments from "which such con- 

 clusions are derived do not justify an assumption 

 as to whether the destruction noted was really the 

 result of heat or oxidation. No reference has 

 been found in any experiments relating to the 

 effect' of heat and oxidation in which the oxygen 

 content of the product or of the cooking water 

 has been taken into account. Practically all 

 fruits contain more or less atmospheric oxygen 

 both in solution and mechanically trapped. To 

 eliminate this a high vacuum is not sufficient un- 

 less the container is jarred by rather sharp blows. 

 More important is the oxygen held in solution by 

 the. water used for cooki-ng. This can not be re- 

 moved with less than five minutes boiling, nor is 

 a vacuum eifective unless the container is jarred. 

 For temperatures less than boiling, hours are re- 

 quired, and during this time the dissolved oxygen 

 would be more available for oxidation of the 

 vitamin than the oxygon of the air which is in 

 contact with the surface. Air-free water dis- 

 solves air very readily and therefore must be 

 kept out of contact with air until used. 



The chick as an experimental animal in vitamin 

 studies. II — With respect to the fat-soluble 

 vitamins: A. D. Emmett and Gail Peacock. 

 Ckintinuing the study of comparing the chick with 

 the rat and pigeon the findings relative to the 

 fat-soluble vitamins indicate in the case of the 

 White Leghorn breed that they are fairly suit- 

 able for test purposes. In marked contrast with 

 the pigeon, the fat-soluble vitamin requirements 

 of the chicken are very much greater. The most 

 prominent symptoms are weak legs, partial paral- 

 ysis, enlarged knee joints, dropping wings, weak 

 eyes, accompanied by xerophthalmia which stimu- 

 lates roup, diminished pigmentation of comb, bill, 

 legs and feet, labored breathing, poor oxidation 

 and loss in weight. In other words, the chick 

 (male or female) needs both the antirachitic and 

 the antiophthalmic fat-soluble vitamins, while the 

 pigeon appears to need relatively little of either. 

 A lack in these requirements is apparently more 

 markedly evidenced in chicks three to four weeks 

 old than in those that are six to nine weeks old. 

 In fact, the onset of the sj'mptoms are so rapid 

 in the younger animals that it is very difficult to 

 bring about a correction of the ailments before 

 death ensues. For practical test purposes our 



data, which includes some 600 birds, suggest that 

 chicks about seven weeks old are the most suit- 

 able. Compared with the rat, the chick has its 

 limitations as a test animal. It occupies more 

 space, consumes more food, has a greater range 

 of variation in rate of growth, being more diffi- 

 cult to handle and bring through the early and 

 critical period of growth. 



MilJc and ice cream as fatty foods: Jerome 

 Alexander. Since milk contains 88 per cent. of. 

 water, the legal 3 per cent, fat means 25 per cent, 

 of the total solids, so that milk is a fatty food. 

 When the casein coagulates it mechanically en- 

 traps the fat, thus forming a greasy curd which 

 is hard to digest. Cows ' milk has a low protective 

 ratio, i. e., the ratio of casein to lactalbnmin, and 

 therefore readily forms greasy curds nnsuitable 

 for the human stomach. Increasing the protective 

 ratio by adding any colloidal protector (gelatin, 

 eggs, etc.) prevents this difficulty, and is 

 of especial importance in ice cream, where the 

 fat content is much higher than in milk. The 

 effect of colloidal protection in artificial milks 

 and cheese is still to be worked out. 



A new method for the determination of vanillin: 

 H. C. Bashioum and Pred Y. Hereon. This 

 method depends upon the properties of the alde- 

 hyde group rather than those of the phenolic 

 group as is usually the ease. In practice, the 

 solution containing vanillin is saturated with 

 hydrogen sulfide in the presence of hydrochloric 

 acid, whereupon a white precipitate of thio- 

 vanillin is produced. The precipitate is filtered 

 off, washed with water and then dissolved in 

 dilute sodium hydroxide solution in which it easily 

 dissolves, producing a yellow color, the intensity 

 of which is proportional, within limits, to the con- 

 centration of thiovanillin. 



. The soda equivalent of sour milk used in 

 baking: Mary P. Wilson and H. A. Webb. 

 Baking soda and sour milk can not be titrated 

 together with any known indicator. A method 

 of preparing alizarine test paper of approximately 

 N/20 strength (one No. 3 quinine capsule of soda 

 in Vi standard cupful of water), drying and 

 "spotting" with mixtures of the N/20 soda, 

 measured in drops, and % teaspoon of the sour 

 milk under examination, was worked out. When 

 the spot shows no color change, the number of 

 spots made permit calculation of the equivalent 

 amounts of baking soda or baking powder per 

 cup of milk of any degree of acidity. 



Charles L. Parsons, 



Secretarii 



