Oils andZFats. 



felt. Consumers, who of course will be 

 able to take advantage from the posi- 

 tion, will be glad of an opportunity of 

 busing this popular and useful oil at 

 exceptionally favourable terms for some 

 time to come. 



Several years ago we showed that 

 Java citronella oil contains citronellal, 

 geraniol and d— citronellol. We were 

 also able to prove the presence in the 

 oil of methoxylgroups, which points to 

 the occurrence of methyleugenol, a body 

 which had already been found by us in 

 Ceylon citronella oil. So far, no further 

 constituents had been made known, but 

 we have recently succeeded in isolating 

 a previously unknown constituent from 

 Java citronella oil, to wit, citral. From 

 a large quantity of Java citronella oil 

 which had a clearly perceptible odour of 

 citral, a small fraction was redistilled 

 repeatedly, and the fraction distilling 

 over between 98 and 100° (7 mm.) (di5° 

 0,8836; a D — 1°30) treated with neutral 

 sodium bisulphite by the familiar pro- 

 cess for the purpose of separating the 

 citral. This body, after being regener- 

 ated and distilled in vacuo, gave the 

 following constants, which agree closely 

 with those of pure citral from lemon- 

 grass oil : b,p. 91 to 92° (5 mm.), dia° 0,8928, 

 aD=0°, no o° 1,48853, m.p. of the napth- 

 ocinchoninic acid 197 to 198*. It should 

 be stated that the citral content of Java 

 citronella oil is but small, being com- 

 puted at about 0,2%. 



We were able, last year, to give some 

 particulars of a citronella oil from 

 German New Guinea which had been 

 submitted to us for consideration. Re- 

 cently we received a similar oil from our 

 German Colonies in the Southern Pacific, 

 and this sample was found to possess the 

 following constants :— d 15 ° 08,964, an— 

 1°20, geraniol and citronellal content 78%, 

 soluble in its own volume and over of 

 80%. alcohol. Although this oil also 

 resembles the Java oil in its general 

 characteristics, its geraniol contents is 

 rather less, and falls below that of the 

 sample examined last year by about 8%. 



The previously existing regulations 

 for the testing of citronella oil having 

 proved insufficient, the Saxon Customs 

 and Excise Authorities have decided to 

 abolish definite regulations for the 

 examination of the oil altogether, and, 

 (as in the case of rosemary oil, q.v.) to 

 leave to the chemists entrusted with the 

 work a free nand in respect of the 

 methods to be applied in determining 

 the value of the oil. In order, however, 

 to afford some guide to the examiners, 

 there has been issued, together with 



S [November, 1910. 



the official announcement, a communi- 

 cation giving the results obtained 

 in the examination of Ceylon citronella 

 oil at the Imperial Techuical Testing- 

 Office in Berlin. We reproduce these 

 results in full :— 



Colour and odour. Great weight is 

 to be attached to both of these, since 

 from the colour and odour of an oil it 

 is possible to obtain an indication of 

 the adulterants for which search should 

 be made in the particular instance. 

 For example ; water-white samples with 

 a pronounced odour of camphor have 

 been met with which were found to 

 consist of mixtures of fusel oil and cam- 

 phor oil with bodies which have not been 

 further investigated, and in the case 

 of these samples it was doubtful 

 whether they contained any citronella 

 oil at all. Citronella oil often has a 

 green colour, resulting from contact with 

 copper in the process of manufacture. 

 Where the copper has not been removed 

 by shaking with dilute aqueous solu- 

 tions of acids the oil generally has a 

 brown colour, which readily turns green 

 on exposure to air. The agreeable and 

 very persistent odour of this oil is often, 

 but inappropriately, described as " balm- 

 like." It is altogeter sui generis, and 

 from this fact is highly indicative of 

 citronella oil. 



The determination of sp. gr. is only 

 useful for the detection of gross adulter- 

 ation with petroleum and other hydro- 

 carbons. The commercial variety des- 

 cribed as " Singapore " oil" has a sp. gr. 

 of 0,886 to 0,900, but oil of the "finest" 

 scarcely enters into consideration for 

 denaturing-purposes. The great bulk of 

 the oil of commerce, known as "Lena 

 Batu," has a sp. gr. of 0,900 to 0,920. 

 The addition of petroleum lowers the 

 density, but such an addition must be 

 considerable before it can be detected 

 absolutely by this factor. 



The fact of solubility in alcohol serves 

 for the detection of petroleum or of 

 fixed oils, Citronella oil which has been 

 adulterated with a not too large pro- 

 portion of petroleum gives a clear solu- 

 tion with from 1 to 2 volumes of alcohol, 

 (i.e., 80 % alcohol) when further diluted 

 the solution turns milky, and when it is 

 left to stand for some time drops 

 separate out on the surface. Where the 

 adulterant is a fixed oil, dilution with 

 an equal volume of alcohol is sufficient 

 to produce turbidity and when the 

 sample is left to stand the fixed oil 

 settles in drops at the bottom, 



It is only the formation of drops which 

 affords a certain clue to adulterations of 

 this nature, inasmuch as "pure" com- 



