— 59 — 



periments. The optical rotations, both of the volatile oils and of the cor- 

 responding fractions, showed but slight differences, the values, taken in 

 their entirety, being practically the same in each case. For distillation 

 in vacuo Cocking uses a large splash-head of special design, of which a 

 sketch is given in his article, and by which any bumping-over of the con- 

 tents of the flask is obviated. Distillation is continued until the manometer 

 commences to fall, the fall indicating the commencement of the decom- 

 position of the distillation-residue. 



Cocking again asserts that in his experience the volatile oils from all 

 genuine copaibas have a higher rotation than the first 10°/<> distilled in vacuo 

 from them. With several samples which gave the reactions for Gurjun 

 balsam, and in which the proportion of the adulterant was estimated to 

 be from 5 to 6°/o, the distillation-test yielded results similar to those ob- 

 tained by Parry with Maracaibo balsams. 



Coriander Oil. Contrary to all expectations, and in spite of the fact 

 that the failure of the crop might have been held to warrant a serious 

 advance, the prices of coriander oil have continued to move within mo- 

 derate limits. The reason of this is no doubt that the demand for the oil 

 has fallen off considerably. We have already on a previous occasion 

 drawn attention to this fact, and recent experience has confirmed our 

 observation. As a result of this reduced consumption the prices have 

 remained on the same level as last autumn, and our fear of a further 

 increase has fortunately not been realized. 



Costus Root Oil. We again draw attention to the exquisite oil 

 distilled by ourselves and we invite our friends to ask us for special 

 quotations when important quantities are required. We are in a position 

 to supply costus root oil very cheaply indeed. 



In the Seifensieder Zeitung und Revue uber die Harz-, Fett- und 01- 

 industrie [39 (1912), 160] there is an article by H. Mann on the use of 

 costus root oil in perfumery from which we take the following: Although 

 costus root oil imparts a touch of distinction to articles prepared with 

 it, it is but little used, probably, in part, because it cannot always be 

 procured. The odour of the freshly-distilled oil is at first not exactly 

 pleasant, but gradually it develops a most agreeable violet-like aroma, 

 which also helps to fix other odours. The employment of old oil is not 

 to be recommended, as it possesses an unpleasant accessory odour, 



fyhich easily penetrates other odours, and thus has a predominant effect, 

 t is advisable to stock the oil in the form of a 10% alcoholic solution. 

 Used in conjunction with vanillin and Portugal oil in particular it produces 

 excellent scents. Many French powders owe their popularity to the odour 

 of costus root oil. 



Cubeb Oil. The high prices have remained unchanged, for there has 

 been no alteration whatever in the position of the cubeb market. The 



