— 47 — 



of seminormal potash liquor, any free acid which may have been 



present having been previously carefully neutralised. The time of 



saponification must be at least one hour. 



The reason therefore why we are not so enthusiastic about the geraniol 

 test as are those interested in the subject in England, and why for the 

 present, and so far as regards the trade in Ceylon itself, we continue to 

 hold to a test for Ceylon citronella oil which can be carried out by anybody 

 without special knowledge or trouble, is not to be sought in opposition 

 to the test itself, but rather in the difficulties of carrying it out. The 

 method known as "Schimmers test" to which we adhere may again be 

 briefly repeated here in its original form. By this test citronella oil must 

 give a clear solution with 1 to 2 vols. 80% alcohol at +20°C, and this 

 solution must remain clear or may at most show a slight opalescence 

 upon the addition of up to 10 vols, of 80% alcohol. Even after being 

 left to stand for several hours, no drops of oil may separate out from 

 the solution. As it has been shown in the course of years that oils which 

 have been adulterated to a moderate extent also stand this test, we proposed 

 some considerable time ago 1 ) an "increased test" under which an oil after 

 being diluted with 5°/o of Russian petroleum must also answer the above 

 test. We have been able to convince ourselves both in our laboratory 

 here as well as by experiments on the spot that really pure Ceylon citronella 

 oils are able to stand this "increased test", and that contradictory statements 

 which have been circulated from England are without any foundation. 

 Further experiments have gone so far as to show that pure Ceylon 

 citronella oil will answer the test even when instead of being diluted with 

 Russian petroleum it is diluted with 5% of the rather more sparingly 

 soluble American petroleum. Where, therefore, Russian petroleum is not 

 available American may be used. In that case, however, the opal- 

 escence is a little more pronounced, but here, too, no drops of oil may 

 separate out from a solution of 1 : 10. When the 10 vols, of alcohol is 

 being added the glass cylinder should only be moderately tilted, because 

 otherwise oil which may have separated out is so finely suspended as to 

 make observation very difficult. 



If our proposals had long ago received the attention which they merit, 

 and if Schimmel's "increased test" had been generally introduced into 

 commerce, the present discussion would be wholly superfluous, for in that 

 case there would no longer have been any complaint of bad quality, 

 seeing that ready solubility also affords a certain guarantee for a sufficient 

 geraniol-content. To the objection that ways and means would be found 

 in Ceylon of so preparing adulterated oils that they would pass the 

 "increased test", we may answer that the same maybe said with exactly 

 the same amount of justification of the geraniol test. 



x ) Report April 1904, 32. 



