54 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



number of manufacturers have changed or are remodeling their 

 phinfs (o meet the demands for a clean, sound product. The old 

 methods have been largely abandoned, as they proved wasteful and 

 deleterious to the product. 



An investigation concerning the coloring and facing of teas was 

 undertaken at the request of the Treasury Department. This in- 

 vestigation resulted in the devising of a new method for this deter- 

 mination, which, with slight modifications, has been adopted as the 

 official method of the Treasury Department to be used by the tea 

 testers of that department. 



In the line of routine work, 1,298 interstate samples and 3,066 

 miscellaneous samples have been examined; these included spices, 

 fruit products, dried fruits, cattle foods, eggs, nuts, sausage, mince 

 meats, olives, candies, chocolate, cocoa products, teas, coffees, infant 

 and invalid foods, and textiles. 



PLANT PHYSIOLOGICAL CHEMISTRY. 



The past year's work of the Plant Physiological Section has in- 

 cluded investigations on starch and starch products, potato drying, 

 graham flour, canning tomatoes, and baking powders containing small 

 amounts of calcium sulphate. The special work comprised investi- 

 gations in bread making and macaroni manufacture and also baking 

 tests with flavoring extracts and with various egg products. 



SPECIAL INVESTIGATIONS. 



The study of the presence of arsenic in shellac and gelatin and 

 other foods has been continued. A prominent feature of the vinegar 

 work has been the determination of formic acid in vinegar adulterated 

 with acetic acid made from pyroligneous acid. In cooperation with 

 the various health authorities of several States, much good work has 

 been accomplished by joint investigation and examination of the 

 waters, oysters, and clams from various beds. As a result, many 

 oyster sections which have shown pollution have been closed by 

 State authorities as a source of edible oysters. 



DRUG INVESTIGATIONS. 



The Drug Division has been engaged in studying the composition, 

 adulteration, and misbranding of drugs and chemicals, including 

 those products imported into the United States or shipped in inter- 

 state commerce and found on our markets. Color reactions for the 

 purity of asafetida have been established, as well as a quantitative 

 constant in the lead number of the purified resin. The same reac- 

 tions were carried out on the well-known adulterants of asafetida. 

 Attention has been given to the estimation of morphin, showing 



