JULT 7, 1922] 



SCIENCE 



23 



led to a comparison of the phosphate and tartarate 

 baking powders in addition to the flour problem. 

 This work is still under way. 



Composition and nutritive value of yeast grown 

 in vitamine-free media: Juanita E. Daeeah. The 

 problem here was to determine the nutritive value 

 of yeast grown from such substances as extracts 

 of wheat and alfalfa, after a series of treatments 

 to destroy the vitamine content. The media of 

 B. MacDonald and McCoUum was adopted for 

 the experiments, but Avith a higher concentration 

 of sugar. In addition, oats with vitamine de- 

 stroyed were added. Eats and guinea pigs were 

 given various diets, and the results were recorded. 

 The author 's conclusions are : 1. Yeast may be 

 readily grown in vitamine-free media through an 

 exceedingly large number of transfers. 2. Yeast 

 grown in this way contains protein and nitroge- 

 nous bases of undoubted nutritive value. 3. Evi- 

 dence of dietetic value of yeast grown in such 

 media is not substantiated. There was only very 

 slight indication of presence of water-soluble B, 

 and none of fat-soluble A or water-soluble C. 



New sources of water-soluble C and fat-soluhle 

 A in the southeast: Juanita E. Dareah. New 

 sources of these vitamines have been found; water- 

 soluble B and C are abundant in Jerusalem arti- 

 chokes, and fat soluble A is fairly abundant in 

 Avocado pears. Five guinea pigs were fed scurvy 

 diet and succumbed in three weeks in so far as to 

 show unmistakable symptoms of scurvy. Two of 

 these died. One had just been through a previous 

 attack of scurvy and had recovered. Another 

 died, due to chilling on a cold day, when there 

 was a delay in securing the artichokes. The other 

 three recovered entirely on addition of the Jeru- 

 salem artichokes in five gram quantities per diem, 

 added to the usual scurvy ration. When protein 

 and mineral salts are supplied in suitable 

 amounts, there is sufficient water-soluble B in 

 Jerusalem artichokes to promote normal growth 

 in white rats, when fed as the sole source of this 

 vitamine in quantities of three grams dried arti- 

 choke to ten of the dry water-soluble B free mixed 

 diet. There is sufficient fat-soluble A in Avoca- 

 does to promote considerable growth in white 

 rats; and to prevent sore eyes for a very long 

 period, no xerophthalmia was induced. This is 

 true of a diet adequate in other respects in pro- 

 tein, vitamine content and energy value. No re- 

 production tests have been secured. 



Foods, facts, fancies and follies : Edwabd 

 Gtideman. This paper discusses the subject of 

 foods from the viewpoint of, firstly, their produc- 



tion, distribution, inclusive of adulteration and 

 substitution, and secondly, from the viewpoint of 

 national habits and follies as to consumption and 

 conservation. It calls attention to the exhausting 

 and wastage of good agricultural lands, the same 

 as with other natural resources, and recommends 

 the reclamation and occupation of the 2,225,000,000 

 acres of tillable land now lying barren, by em- 

 ployment of the unemployed, the same suggestion 

 as made by President Roosevelt and Secretary 

 Lane for returned soldiers in 1919, such work to 

 be under direct control and supervision of the 

 federal government. Such action would provide 

 labor for thousands of men, would greatly increase 

 the resources of the nation and would create a 

 demand for the products of the government's 

 nitrogen fixation plants, without coming into com- 

 petition with existing fertilizer manufacturers. 

 It is a paper for the layman vrithout the use of 

 scientific or technical terms. 



The determination of hydrogen sulfide iy foods 

 when cooTced at various temperatures: Edward E. 

 KonMAN. A method has been developed in which 

 the food is heated in a flask in an autoclave. The 

 flask is fitted with a stopper carrying two glass 

 tubes. The inlet tube passes to the bottom of the 

 flask and opens in the autoclave. The outlet tube 

 passes through the pine wood stopper of the flask 

 and up through the top of the autoclave and 

 carries a glass stopcock. The autoclave is sup- 

 plied with steam from a boiler. By this device 

 food may be heated at any temperature for any 

 length of time, while the water content remains 

 constant. At the same time the hydrogen sulfide 

 formed can be collected and determined as barium 

 sulfate. The method is a quantitatively accurate 

 one. Its application to other steam distillations 

 imder pressure is considered. It should have wide 

 application in many organic preparations. 



Studies of the availability of organic nitroge- 

 nous compounds. II (by title) : C. S. Robinson. 



The interpretation of mechanical analysis of 

 soils as affected by soil colloids: R. 0. E. Davis. 

 So-called mechanical analysis of soils is one in 

 which the soil is divided into its mineral constitu- 

 ents according to the grain sizes of the material. 

 This mechanical analysis has an important bearing 

 on indicating the character of the soil and its 

 physical properties. Erom the results of such an 

 analysis may be judged the water-holding ca- 

 pacity of soils and their relations to tillage opera- 

 tions, and, more important, their probable pro- 

 ductivity. In carrying out such an analysis it be- 

 comes absolutely necessary, first, to break up all 



