BUREAU OF CHEMISTRY. 461 



varieties of barley when grown year after year on the same experi- 

 mental field. 



(5) Milling and baking experiments to determine the value of 

 wheat. These are supplemental to the chemical analyses which have 

 been made for a number of years. At the present time an extensive 

 series of milling and baking tests is being conducted, which in con- 

 nection with the chemical analysis of the wheat will no doubt be of 

 great value, scientificall}^ and technically. 



(6) The study of dilTerent varieties of potatoes for starch content. 

 The growing of potatoes on an extensive scale would yield greater 

 profits if care were taken to select only those varieties that are heavy 

 yielders and are at the same time rich in starch. The tests made on 

 potatoes were for starch content with a view to the improvement of 

 the varieties that should be grown. 



Other investigations made in this laboratory are: 



(1) The study of cereals during the first few weeks of their growth 

 and the eTect of various plant foods on the composition of young 

 plants. The work heretofore has been done mostly with mature 

 crops or with growing crops after the plants had become well started. 

 This experiment is to determine the changes which take place during 

 the first two weeks of the history of the plant. Wheat seedhngs were 

 generally grown because they are easy to grow and manipulate. 



(2) The study of the effect of plant food on the formation of roots 

 of young plants. The work just described led to the study of the 

 effect of the reaction of the solution on the root development. It 

 was noticed in the preceding investigation that a marked erfect was 

 produced when the seedlings were grown in water culture in the 

 presence of certain salts. This investigation was then undertaken to 

 determine some means of correcting the undesirable effects thus 

 produced. 



(3) A study of the use of partial substitutes for flour in the baking 

 of bread, as. for example, cottonseed flour, peanut meal, soy-bean meal, 

 and other high-protein products. A new use for cotton seed has been 

 found, namely, the making of cotton seed flour, containing over 40 

 per cent protein, as compared with the 12 per cent present in ordinary 

 wheat flour. This cottonseed flour is being extensively used in por- 

 tions of the South for mixing with wheat flour for the baking of 

 higher protein bread. These mvestigations will cover not only the 

 use of cottonseed flour in bread making, but the use of other high pro- 

 tein substances as partial substitutes for wheat flour. Such mixtures 

 of course would be sold under their proper names and not as wheat 

 flour. 



(4) The study of Graham flours found on the market. The fre- 

 quent requests of the division of foods for the testing of Graham 

 flours to determine whether they are straight or mixed have led to an 

 investigation wliich has been conducted by a chemist who is also a 

 milling and baking expert, and the results of the work will be compiled 

 in the near future. 



(5) A study of starches from different plants. The experiments 

 conducted this year are prelmiinary in character and include studies 

 of the chemical and physical properties of starches from difl'erent 

 sources and of a means for the more complete extraction of the 

 starch from the tubers than is obtained at the present time. 



