400 



[May, 1910. J 



OILS 



CITRONELLA-OIL TESTS. 



(From the Chemist and Druggist, 

 Vol. LXXVI., 1571, March, 1910.) 



Reference was made in the Chemist 

 and Druggist last week, p. 310, to the 

 persistent adulteration of bulk citro- 

 nella oil, and the desirability for 

 altering the terms of sale in London. 

 It is a long standing complaint (we had 

 almost said " joke") that citronella oil is 

 faked to pass Schimmel's test, and 

 repeated efforts to establish an honest 

 basis so as to secure supplies of pure 

 bulk oil have had little success. In the 

 first issue of Mr. John C. Umney's " Per- 

 fumery and Essential Oil Record," rea- 

 sons for a "London Standard" were 

 advanced. Mr. Umney wants the oil to 

 be: sp. gr. 0'900 to 0-915 opt. rot. 

 (100 mm.) 0° to— 15°, ref. ind. about 1,4800 

 acetylisable constituents at least 60 per 

 cent., and solubility 1 vol. in 2 to 3 vols, 

 of 80 per cent, alcohol, the solution re- 

 maining clear on the addition of the 

 same solvent up to 10 vols. The first, 



second, and third of these factors are 

 also recommended by Parry and Benuet, 

 who agree generally with the others, 

 and they are well suited to distinguish 

 oils which are pure from those which 

 are adulterated with kerosene or resin 

 spirit. In the second number of the 

 '' Record," published this week, the 

 Editor's suggestion is supported by, 

 ninougst others, Mr. Holman Kingdon, 

 buyer for Messrs. John Crosfield & Sons, 

 Ltd., who emphasises the desideratum 

 that "The only real standard is purity, 

 and this possibly with determination of 

 geraniol content the only real basis for 

 any judgment of value." A leading Minc- 

 ing Lane broker also insists that the 

 oil should be sold on geraniol constituent 

 (geraniol and citronellal) stated as gera- 

 niol. The " Record " adds that the pro- 

 posed London standard has aroused 

 widespread interest, and the Editor is 

 confident that in a short time difficulties 

 as to citronella oil will have vanished. 

 A useful service will have been done by 

 the "Record" in securing agreement on 

 this matter thus early in its career. 



EDIBLE PRODUCTS. 



PRODUCTS OBTAINED FROM 

 CACAO, 



(From the Agricultural News, Vol. IX., 

 No. 203, February 5, 1910.) 



The three cacao products known to 

 commerce are : cacao butter, cacao 

 powder, and cake chocalate, the manu- 

 facture of chocalate requiring skill and 

 knowledge in special degree. The buttei 

 is merely the oil or grease of the kernel, 

 usually extracted by pressure and leav- 

 ing a residue still containing a certain 

 amount of vegetable fat, which, being 

 ground as will be explained later, is used 

 in making the beverage commonly 

 known as cacao. When chocolate is 

 intended to be produced, the carefully 

 cleaned kernels are crushed into a mass, 

 flavoured and manipulated according to 

 many methods, and then, after an addi- 

 tion of pure cacao butcer has been made 

 to the natural content of the mass, it is 

 pressed into small cakes, and sold. 



The cacao bean is composed, by weight, 

 of 88 per cent, of kernel and husk and 

 12 per cent of shell. The shells and husks 

 are treated chemically in Holland for the 

 production of a low-grade butter, the 

 reduction being effected by ether or 



benzene. The kernel, which contaius 

 50 to 55 per cent, of oil, was formerly 

 treated, when the extraction of butter 

 was contemplated, by boiling, roasting 

 and crushing in ten times its weight of 

 water ; the oil then rising to the surface 

 was decanted, and the residue pressed 

 mechanically for the elimination of such 

 butter as it still contained. This method 

 has been abandoned, aud the kernels, 

 freed from their envelopes, are now 

 ground to a mass, brought to a temper- 

 ature of from 60° to 70° O, placed in 

 coarse linen sacks, and finally pressed in 

 steam-heated machines. After this first 

 application of pressure the cocoa cake 

 contains from 20 to 35 per cent of fat ; 

 it is then ground and repressed until 

 not more than 15 per cent, of the fatty 

 matter remains. The oil or grease 

 which has been extracted is called 

 "cacao butter" which is used chiefly by 

 cacao manufacturers, and, in smaller 

 quantities, in the soap, perfumery, and 

 pharmaceutical industries, in which, 

 owing to its neutral qualities, it is 

 especially valuable. 



Fresh cacao butter is yellowish white, 

 but if exposed tolight. it becomes entirely 

 white, aud possesses a mild odour of the 



