BUREAU OF CHEMISTRY. 431 



AsAFETiDA. — During the last year a large number of shipments of 

 asafetida adulterated by the addition of foreign gums such as gal- 

 banum, olibanum, and ammoniacum have been presented for entry. 

 This undoubtedly is due to the enforcement of the requirements of 

 the United States Pharmacopoeia with reference to the content of 

 alcohol-soluble material. The investigations and studies necessary 

 for the identification of these foreign gums have been made. 



Essential oils. — The inspection of the essential oils has been 

 extended during the past year to include all of those recognized in 

 the United States Pharmacopoeia, the work heretofore having been 

 confined almost entirely to the orange and lemon oils. No particular 

 investigation as to methods have been conducted, but data as to the 

 composition of the oils presented for entry has been secured as a basis 

 for future investigations. 



PITTSBURGH LABORATORY, 



The character of the samples examined at the Pittsburgh Labora- 

 tory was quite different from those of 1910, and a great deal of work 

 was required for some classes of materials, notably candies. In addi- 

 tion to the regular examination of official samples, investigations of 

 sirups and medicated soft drinks have been made. The applicabihty 

 of the Rohrig tube to the determination of fat in cocoa and chocolate 

 showed that this tube could be used in the determination of fat in 

 cocoa with a double extraction, but was inapplicable to chocolate. 

 A method for the determination of caramel in vanilla products has 

 been elaborated and promises excellent results; this method is now 

 being thoroughly tested on different kinds of vanilla extracts. 



An important part of the work at this laboratory for the preceding 

 year has consisted in the examination of a large number of samples 

 of candies coated with shellac and other resins. Some of the earlier 

 samples of tliis character examined showed the product to be coated 

 with shellac containing rosin, and in some cases quite an appreciable 

 amount of arsenic. The latter samples of candy show shellac only, 

 which, however, in all cases contains a small amount of arsenic. 

 Some manufacturers stated that they were willing to stop using the 

 shellac provided other manufacturers will do likewise. 



OTHER PORTS. 



The following laboratories have made special studies of the sub- 

 jects mentioned : 



Buffalo laboratory. — Investigations on the determination of 

 fat, sugar, and cocoa shells in cocoa products were made. Studies 

 were begun of various methods for the determination of fat in dried 

 milks. Some work on the occurrence of sucrose in grape juice and 

 the change on standing in tlie composition of grape juice to which 

 sucrose had been added was begun. This work on grape juice was 

 undertaken to determine whether added sucrose would become 

 inverted on standing so as to make it difficult to determine upon 

 analysis whether cane sugar had been added at the time of manufac- 

 ture. 



