BUREAU OF CHEMISTRY. 441 



Peppermint oil nndoubtedly constitutes one of the most important 

 industries in essential oils in the United States. Investigations are 

 in progress to determine whether or not one variety of plant grown 

 under varying conditions would produce oils superior to those made 

 from another variety grown under similar conditions, and whether 

 or not the oils so produced comply with the standard set by the 

 Pharmacopoeia. Quite a number of authentic oils were gathered in 

 southern Michigan, but no conclusions have been reached as yet. A 

 sample of California peppermint oil was also procured and was 

 found to contain an unduly large amount of menthol. Other oils 

 under investigation are spearmint, tansy, and wormwood. 



The quantitative methods for determining the chief odor-bearing 

 constituents are being studied. These methods involve the deter- 

 mination of many of the ketones and aldehydes present in the vari- 

 ous essential oils. A special study of the hydroxylamin titration 

 method for estimating ketones and aldehydes is in progress in order 

 to determine whether or not this method is more generally applicable 

 and reliable than the alkaline sulphite or bisulphite solutions at 

 present used. Many of the ketones do not react with the sulphite 

 solutions. From the results obtained so far it is apparent that this 

 method when carefully worked out will give closely concordant 

 results in the hands of different workers, and in most cases the prod- 

 uct of the reaction can be recovered and its chemical identity estab- 

 lished. The method has already been compared with the other assay 

 methods in conjunction with spearmint and dill oils. The method 

 also promises well for determining the quality of such oils as tansy, 

 wormwood, pennyroyal, and dill, for which at present there is no 

 satisfactory method of assay. The official method for determining 

 the presence of dimethyl sulphid in oil of peppermint as prescribed 

 by the United States Pharmacopoeia is also under investigation. 



The analysis of certain brands of root-beer extracts on the market 

 having revealed the presence of a considerable quantity of free sali- 

 cylic acid, the question of the hydrolysis of methyl salicylate under 

 the conditions obtaining in the manufacture was raised and it became 

 necessary to establish whether the salicylic acid found is added as a 

 preservative or whether it is the result of hydrolysis of methyl sali- 

 cylate. The indications point to the latter hypothesis as the correct 

 one. in Avhich case salicylic acid may appear in the finished product 

 without having been added as such. 



The interstate samples of essential oils so far examined show that 

 they are either pure or the variation from the standard prescribed 

 by the Pharmacopoeia is very slight. In many instances, however, 

 the oils are evasively labeled with such phrases as " for technical use 

 only " or " not for medicinal use." 



SYNTHETIC PRODUCTS. 



In former years it was customary for manufacturers of proprietary 

 remedies, particularly those for headache, rheumatism, and la grippe, 

 to represent them as containing drugs of exceptional curative 

 powers, while, as a matter of fact, the active ingredients were usually 

 acetanilid, antipyrin. some salicylate, with frequently cafFein and 

 quinin. A marked change has taken place under the operation of 



