BUREAU OF CHEMISTRY. 559 



Essential Oils Used foe Fl.vv'oring Food PBODrcTS. 



Much time has been devoted to research work on the methods for 

 the determination of the active constituents of essential oils and to 

 general methods for the detection of their adulteration. It was 

 found that many of the methods of analysis, as well as physical con- 

 stants, given in the cuiTent edition of the Pharmacopoeia were not 

 up to date, so that the work on each individual class of oil has had to 

 be done simultaneously with a special investigation upon samples of 

 known origin. It is hoped that the results of these investigations 

 will shoi-tly be published as a circular. 



The work included a general investigation upon oil of bitter 

 almond, with special reference to methods for determining the amount 

 of benzaldehyde therein, but was also extended to include the deter- 

 mination of hydrocyanic acid, benzoic acid, and of chlorin; the 

 determination of cinnamic aldehyde in cinnamon and cassia oils, 

 together with the detection of added rosin; and the detection of 

 glycerin in lavender oils. 



Edible Oils. 



The work on the commercial production of peanut oil taken up 

 last year has been continued. Sixteen lots of material (supplied in 

 part by the Bureau of Plant Industry) have been expressed in the oil 

 expeller under varying conditions of moisture content and tem- 

 perature and the most economical method of treatment for Spanish 

 and Virginia peanuts determined. 



The preparation of samples of oils of Icnown origin and purity 

 has been continued this year, and there have been added to the stock 

 sunflower oil pressed from the seeds of the Mammoth Russian variety, 

 coconut oil made from fresh nuts dried in an evaporator and pressed 

 in an expeller. and several samples of pecan oil, which were pressed 

 out in a hydraulic press from material supplied by the Bureau of 

 Plant Industry. 



The chief of the oil, fat, and wax laboratory, as an associate referee 

 of the .Association of Official Agricultural Chemists, has conducted 

 investigations on several methods proposed for the analysis of fats 

 and oils, some of which will be adopted officially. 



In collaboration with the Interstate Cottonseed Crushers' Asso- 

 ciation's committee on uniform methods, a series of analyses have 

 been made on cottonseed products and recommendations as to the 

 best methods for adoption as official by that association transmitted 

 to them. 



The study l)ogun last year on the chemical composition of soft- 

 shell pecans and their oil, with a view to determining whether the 

 composition would shed any light on the distinguishing features of 

 various varieties and the effect of different climatic conditions upon 

 this chemical composition, has been continued in collaboration with 

 the Bureau of Plant Industry and will shortly appear as part of a 

 bulletin of the Division of Pomology. 



Miscellaneous. 



A number of investigations have l")oen undortnkon to which a vary- 

 ing amount of attention has been paid. Some additional study has 



