252 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



RESEARCHES IN AGRICULTURAL CHEMISTRY. 



The application of chemistry to agriculture in the most compre- 

 hensive sense has been one of the chief functions of the Bureau of 

 Chemistry since its establishment, although in recent years this phase 

 of the work has received less public attention than the work on the 

 enforcement of the food and drugs act. The food work, however, is 

 an outgrowth of investigations into the composition of foods con- 

 ducted originalW as a chemical agricultural study. While the prac- 

 tical application of the results of research is not always apparent for 

 a considerable period after the researches are completed, the basic 

 studies in agricultural chemistry have led to results of the greatest 

 practical importance. Processes for the greater utilization of farm 

 crops and production by-products have been developed and improved 

 anrl new manufacturing industries established, work more fully out- 

 lined in another part of this report. 



ODOROUS CONSTITUENTS OF FRUITS. 



Investigations pertaining to the odorous constituents of certain 

 fruits, particularly the a[)ple and the peach, are in progress. A paper 

 on the odorous constituents of the peach was published during the 

 year. A patent for the preparation of a synthetic apple oil has been 

 granted as the result of these researches. A paper describing the 

 results of a further investigation on the apple odor has been prepared 

 for publication, and also one on tlie presence of niethylanthranilate 

 in grape juices. 



STUDIES ON VEGETABLE OILS. 



The economic importance of a further utilization of vegetable oils 

 and of the production of oils from sources not now available has led 

 the bureau to make a systematic study of the chemical composition of 

 vegetable oils. These studies include investigations to determine the 

 physical and chemical characteristics of the principal commercial 

 vegetable oils, especially those produced from oil seeds grown in 

 this country. The chief vegetable oils manufactured in the United 

 States include castor, coconut, corn, cotton seed, linseed, mustard 

 seed, olive, palm kernel, peanut, raisin seed, rapeseed, sesame, and soy 

 bean. 



During the year investigations on the composition of sunflower-seed 

 oil and soya-l)ean oil have been completed and the results prepared 

 for publication. Work on the determination and identification of 

 the constituents of crude cottonseed oil is under way. Considerable 

 progress has been made in the separation of the free fatty acids oc- 

 curring in the commercial crude cottonseed oil, and a study is being 

 made of the composition of these acids, as no data are available which 

 give this information needed by the oil industry. Work on the 

 method for determining the total amount of neutral glycerides in a 

 crude vegetable oil has been completed and the results published. 

 This is the first time in the history of the great cottonseed industry 

 that a method has, upon investigation, been found applicable to de- 

 termine the neutral oil present in a crude vegetable oil. Researches 

 of this character, which wnll show how to reduce the refining loss, 



