— 46 — 



been possible to arrange that cassia oil is to-day sold everywhere accor- 

 ding to its cinnamic aldehyde content, and lavender oil according to its 

 linalyl acetate content; but these comparisons do not hold good, because 

 every layman can be taught in the shortest possible time to carry out a 

 cinnamic aldehyde estimation, while the ester estimation of lavender oil 

 does not meet with any difficulties in the south of France, where there 

 are plenty of chemists or pharmacists who know how to carry out pro- 

 perly the saponification method. But if our information is correct, the 

 crucial point in the whole question of the geraniol test is just this, that 

 Ceylon does not possess a sufficient number of trained chemists or phar- 

 macists to carry out the necessary examinations, and that the layman can 

 be of no use in this particular matter because he does not possess the 

 knowledge required for chemical work of this nature. Besides this, it is 

 necessary to lay special stress upon the fact that in determination of the 

 total-geraniol content in citronella oil it is particularly necessary always 

 to work under the same conditions, if comparable results are to be ob- 

 tained. In reading through the articles which have been published on 

 the geraniol test, we came, among others, opon a prescription 1 ) which re- 

 ferred to the writer's "own method" to the complete neglect of all the 

 newer investigations, especially those relating to the acetylation of ci- 

 tronella oil 2 ). At the present time in particular this is much to be re- 

 gretted and shows how well-founded is our fear that the determination of 

 geraniol will not always be carried out accurately. We wish to point out 

 again that in the case of citronella oil in particular it is necessary to ad- 

 here strictly to the prescribed method, if the results are to be indicative 

 of the actual total-geraniol content and are to be mutually comparable 3 ). 

 For this purpose we give below a method by which we work in our 

 own laboratory, and which according to our experience produces the best 

 results with mixtures of known geraniol and citronellal content. 



10 cc. each of citronella oil and acetic anhydride with 2 g. 

 anhydrous sodium acetate and a few fragments of porous plate (in 

 order to prevent the liquid from bumping) are kept boiling at an equal 

 temperature in an acetylation flask for 2 hours on the sand bath. When 

 the mixture has cooled, a little water is added to the contents of the 

 flask and the whole is heated for a quarter of an hour upon the water 

 bath under frequent shaking in order to decompose the excess of 

 acetic anhydride. The oil is then separated in a separating funnel 

 and washed with water or, better still, with a solution of common salt 

 until it gives a neutral reaction. Of the acetylated oil dried with 

 anhydrous sulphate of sodium, 1,5 to 2 g. is saponified with 20 cc. 



!) Chemist and Druggist 77 (1910), 896. 



2 ) Report April 1909, 36; April 1910, 154. 



3 ) Comp. Report April 1910, 154. 



