— 116 — 



Notes on Scientific Research in the Domain 

 of the Essential Oils. 



General. 



In an article entitled "La chimie des parfums en 1910", P. Jeancard 

 and C. Satie 1 ) briefly review the work which has been published in the 

 year 1910 in the domain of the terpenes and essential oils. 



A part of Rabak's essay on the manufacture of essential oils in the 

 United States of America, to which we referred in our last Report 2 ), has 

 now been published in the Journal of the American chemical Society [Vol. 33 

 (1911), p. 1242]. 



Analytical Notes. 



In the report on our investigations into the detection of artificial esters 

 in bergamot oil 3 ) we described a method of testing for terpinyl acetate 

 based upon the shorter time required for the saponification of linalyl 

 acetate as compared with terpinyl acetate. Two tests were to be made 

 by the same method, and after saponification extending over V- 2 and 1 hour 

 respectively the ester value was to be determined, and the presence of 

 terpinyl acetate to be concluded, from a possible difference between the 

 two readings. A short table was given showing the differences which 

 had been found by us in the pure esters as well as in pure bergamot oil 

 and in bergamot oil adulterated with terpinyl acetate. An addition of 5% 

 terpinyl acetate to pure bergamot oil still showed a difference in the two 

 ester values of 3,5, but no smaller addition could be detected with certainty, 

 because the difference became too slight and fell within the limits of 

 possible error. 



Now, since more heavily adulterated oils would already arouse suspicion 

 on account of their constants, and as additions of less than 5°/ terpinyl 

 acetate would only slightly affect the oil in question, we were anxious so 

 to improve the method so that it could be employed to detect positively 

 smaller adulterations than that stated above. 



After many experiments we have found the method described below 

 to be more accurate and we therefore publish it here in completion of 

 our previous statements. 



Four separate tests should be made with samples accurately weighed 

 in the saponification flask (2 cc. each is a suitable quantity). The oil is 

 then mixed with about 5 cc. alcohol and a few drops of alcoholic phenol- 



*) Rev.gen.de Chim. 14 (1911), 177. From a reprint kindly sent to us. 



2 ) Comp. Report April 1911, 146. 



3 ) Report October 1910, 60. 



