BUREAU OF CHEMISTRY. 449 



nearly so great as that caused by the change due to environment even 

 on the same soil. 



(g) The study of the form in which phosphorus occurs in wheat 

 and cotton-seed meal. As it was intended to use cotton-seed meal for 

 bread-making purposes, it was thought desirable to determine the 

 nature of the phosphorus compounds found therein. 



(A) The study of the translocation of plant food and the elabora- 

 tion of plant material during germination and during the early 

 stages of plant growth. Such studies have been carried on in the 

 past with respect to maturing plants. This study takes up the first 

 two weeks of the plant's life, and the results obtained are expected 

 to be of considerable interest to scientific and practical agriculture. 



In the conduct of this work, approximately 11.000 chemical deter- 

 minations wore made, and over 3.000 other examinations, including 

 milling and baking tests, fermentation tests, physical tests of cereals, 

 and granulation tests on flour. 



ANIMAL PHYSIOLOGICAL CHEMISTRY. 



A proliminaiy feeding experiment on animals to compare the rela- 

 tive nutritive values of glucose and cane sugar was completed. This 

 study has not extended over a sufficient length of time, however, to 

 be conclusive, though the results so far obtained indicate that the 

 animals did not thrive so well on glucose as on cane sugar. 



Analyses of yeast and beef extracts of known origin and a study 

 on the determination of glycerin in medicinal meat preparations were 

 made. 



The work on the deterioration of meats and fish has been continued 

 and is nearing completion. So far the results show that incipient 

 deterioration of meats and fish when kept at low temperatures for 

 periods of six to eight months can be detected by chemical means. 

 The scope of the study has been enlarged in order to determine 

 how long such products should be held in storage, especially with 

 reference to their fitness for food under the food law. 



Progress has been made during the past year in a study of the 

 enzyms Avhich accomplish the digestion of sugars in plants and ani- 

 mals. The laws of the action of one of the most important enzyms, 

 invertase, have been reduced to exact knowledge by accurate quanti- 

 tative study, and from this investigation thei^e has resulted a useful 

 method for estimating cane sugar in agricultural products. By the 

 use of this new method it has been found that a wild plant, which 

 occurs abundantly in Texas and New Mexico, called sotol {Dasylirlon 

 fexanvm), contains 13 per cent of the important sugar fructose. It 

 is planned to examine other related plants by this method. The 

 results of these researches have been published in circular form. 

 There is in progress a study of the enzyms maltose and emulsin, which 

 has for its purpose the development of a method of analysis for the 

 sugars maltose and raffinose. As these enzyms can not in general be 

 employed with certaint]/^ in chemical analysis until the laws of their 

 action are fully known, it is necessary to make first a careful scientific 

 study of their ]^roperties. 



An important investigation arising under the food law was made to 

 determine the value of a so-called "diabetic flour." The excretion 

 of sugar was doubled on feeding a diabetic with a limited quantity of 



73477°— AGB 1910 29 



