BUREAU OF CHEMISTRY. 439 



of unknown origin. A study was also made under artificial condi- 

 tions (imitating as closely as possible those obtaining in processing 

 canned goods) of the solubility of tin plate in organic acids simulat- 

 ing the composition and acidity of vegetable and fruit juices. 



Edible oils. — In collaboration with the Bureau of Plant Industry 

 a study has been begun of the composition of a large number of va- 

 rieties of soy beans and the character of their oil. Methods for the 

 clarification of this oil and of peanut oil have also been studied. 



Analytical methods. — Much progress has been made in the im- 

 provement of methods for the detection of food adulteration. New 

 methods have been devised, improvements have been made in some 

 of those formerly used, and by means of collaborative study the re- 

 sults of the various food laboratories of the Bureau have been brought 

 in closer accord. The method for the quantitative determination of 

 benzoic acid, which jDreviously had been used especially with tomato 

 ketchup, has been investigated in connection with other varieties of 

 foods and found to be generally applicable. 



The exact determination of the character and quantity of the va- 

 rious organic acids in different types of foods is of the utmost im- 

 portance in the detection of food adulteration, since the organic acids 

 of many foods are dissimilar from those of the products with which 

 they are commonly adulterated. A careful study of methods for the 

 detection and estimation of minute quantities of the common organic 

 acids has been undertaken and marked progress has been made. This 

 not only furnishes additional evidence of adulteration, but also 

 valuable data respecting the soundness or decomposition of products 

 from which certain types of food have been made. 



The analytical methods used in foreign countries in testing Amer- 

 ican food products, especially those regarding fats and oils, have 

 been under investigation, with the hope of bringing about some inter- 

 national agreement. The necessity for this work can not be over- 

 estimated, especially with regard to the great quantity of animal fats 

 and oils exported to foreign countries, the acceptance of which is 

 based on chemical analysis. 



Miscellaneous. — A considerable number of the samples examined 

 was not included either in the ordinary investigations of the Bureau 

 or in its work of inspection. Many materials were examined at the 

 request of other departments for the purpose of determining their 

 purity and quality. At the request of the General Supply Committee 

 the division examined 235 samples of food submitted in connection 

 with bids for government institutions. 



DRUG INVESTIGATIONS. 



Both the routine examinations and the special investigations con- 

 ducted by the Division of Drugs, under the direction of L. F. Kebler, 

 are chiefly concerned with the composition, adulteration, and mis- 

 branding of drugs and chemicals imported or found on the American 

 market and shipped in interstate commerce or manufactured or 

 produced in the United States territories or the District of Columbia. 

 The chemical reagents used by the Bureau of Chemistry in its general 

 analytical work are also examined by this division. These hues of 

 work require a study of the methods of analysis, of the standards at 



