— 9 i — 



As we have repeatedly stated, our New York branch disposes of 

 the output of several suppliers of established repute, whose names 

 we are of course precluded from publishing on account of business 

 considerations. 



Although the majority of our suppliers are personally known to 

 us, every delivery which reaches us is subjected to the most severe 

 chemical examination, and we are in a position fully to differentiate 

 between synthetic oil, sweet birch oil, and oil of wintergreen leaves. Quite 

 recently, parties in Carolina and in New England have taken up the 

 distillation of Gaultheria procumbens, and we are expecting sample- 

 consignments of this oil. 



H. D. Gibbs 1 ) reports on the separation of salicylic acid and 

 methyl salicylate, as well as on saponification-experiments made with 

 the ester, problems occurring in the examination of pharmaceutical 

 preparations or of lemonades and other non-alcoholic beverages. The 

 two compounds above mentioned often occur together and it is possible 

 (apart from deliberate addition) that the presence of the acid or its 

 salts may be due to the existence, as an impurity, of free acid in the 

 synthetic ester, wintergreen oil, or sweet birch oil which has been used, 

 or that a splitting -up has occurred. The free acid can be titrated 

 directly. In order to separate it from the ester it is first extracted 

 by frequent shaking with a solution of bicarbonate of sodium of known 

 strength; from this, the ester is removed with chloroform, after which it 

 is acidulated with sulphuric acid 1:3, shaken out with chloroform 

 and determined by titration or by the colorimetric process. By this 

 method, samples of synthetic ester were found to contain o,oii3°/ , 

 such of wintergreen oil 0,025 to 0,02 8 °/ of free acid. In the examin- 

 ation of cod liver oil emulsions the bicarbonate-layer was removed by 

 centrifugal action. The ester extracted by chloroform was saponi- 

 fied by boiling it for half an hour with solution of caustic alkali, after 

 which the chloroform was driven off, the sample under examination 

 filled up to a known volume in an aliquot part of the solution and 

 the salicylic acid content determined. Experiments on the rate of 

 saponification of the ester by means of carbonate and bicarbonate 

 of sodium (by shaking solutions of known strength with an excess of 

 of ester at 30 ), showed that when sodium carbonate was used equi- 

 librium was reached in about a month's time, when the whole 

 of the carbonate had been converted into bicarbonate, whereas in the 

 case of bicarbonate no perceptible saponification was to be observed. 

 When caustic soda solution was employed the saponification was com- 

 pleted in about 24 hours. 



v ) Journ. Americ. chem. Soc. 30 (1908), 1465. Philippine Journ. of Science 3 

 (1908), A. 101. 



