BUKEAU OF CHEMISTRY. 217 



the industry on the subject of proper steels for use in the manufac- 

 ture of tin plate for food containers and on the rust-resisting qualities 

 of different kinds of tin plate has continued. 



RESEARCH. 



PLANT CHEMISTRY. 



The study of poisonous beans offered for import has led to the 

 prejDaration of a monograph on the chemical and botanical char- 

 acteristics of the edible and poisonous beans of the lima type, Phaseo- 

 lus lunatus. Methods have been devised which, upon a laboratory 

 scale, render such poisonous beans fit for food. If they are prac- 

 ticable on a commercial scale, these cheap beans may become avail- 

 able for food purposes. A very simple method for the isolation of 

 the cyanogentic glucoside of these beans, linamarin, has been de- 

 vised, and its enzymatic and acid hydrolysis has been studied. 



In cooperation with the Bureau of Plant Industry, hundreds of 

 samples of soy beans of different varieties, grown in various locali- 

 ties, have been examined to determine the range of variation in com- 

 position dependent upon variety and climate. The beans low in 

 protein were generally high in fat, and vice versa, while the effect 

 of climatic conditions seemed greater than the effect of variety in 

 influencing composition. No correlation was found between the 

 weight per thousand and the fat or protein content. In general, though 

 there are some exceptions, varieties high in protein in one locality 

 are also high in protein in others. Studies have also been made on 

 the manufacture of palatable products from soy beans. 



The study of various seeds offered for import as mustard has led 

 to the preparation of a paper on Chinese colza, discussing the chemi- 

 cal and anatomical characters of the seed, as w^ell as the morpho- 

 logical characters of the plant in different stages of growth. Similar 

 work is in progress on other species of Brassica, such as Japanese 

 mustard {Brassica cernua), Chinese mustard {Brassica juncea), 

 and Eussian brown mustard {Brassica hesserlana) . These, as well 

 as white mustard {Sinapis alba), have been grown successfully in 

 three localities in the United States. 



As part of a cooperative study with the Bureau of Entomology 

 on boll-weevil control, the bureau has published a paper on cotton 

 entitled " Chemistry and Histology of the Glands of the Cotton Plant 

 with Notes on the Occurrence of Similar Glands iii Kelated Plants," 

 and one entitled " On the Chemistry of the Cotton Plant, with 

 Special Eeference to the Upland Cotton, Gossypium hirsutum.'''' The 

 ethereal oil previously reported as occurring in the flowering and 

 fruiting plant has also been obtained from young plants, mainly 

 seedlings. It occurs in small amount, about 0.015 per cent, and is 

 located in glands distributed generally over the plant. If unexposed 

 to light the glands contain, in addition to the oil, gossypol; if ex- 

 posed to light, quercetin or quercimeritrin. Both quercimeritrin and 

 isoquercetrin could be found in the petals. Gossypitrin and gossy- 

 petin, isolated from other types of cotton, were not observed in 

 Upland cotton. 



97335°— AGR 1918 15 



