Oils and Fats. 



20 



"From these facts, I conclude that the merchandise in question is not an 

 imitation of nor a substitute for cocoanut butter, and that it is not dutiable under 

 the tariff act." — Oil Reporter, New York. 



[In connection with this interesting decision of the U. S. A. Circuit Court of 

 Appeal we have to remark that it is to be regretted that a difference in spelling of 

 these products is not adhered to. A certain amount of confusion is always liable to 

 arise when the commercial products of the two plants Theobroma Cacao and Cocos 

 nucifera are both spelled "cocoa." Cocoa is a correcb spelling of cacao products; 

 "coco " the spelling for the coconut palm and its products.— Ed. T.A.& Mag. C. A. S.] 



TESTING OP COPRA OIL FOR PURITY. 

 The use of copra coconut oil for soap making has of late years increased 

 enormously, and hardly in a less degree for the manufacture of alimentary vegetable 

 fats. It is often mixed with less expensive oils, such as cottonseed, sesame, arachis 

 and even hydrocarbon oils, at the risk of altering its properties and causing 

 serious injury to the industries in which it is used. 



Alkaline Saturation.— 5 grams of the pure, dry, fatty acids from copra oil 

 require 24*1 c.c. of normal soda, whereas 17*7 c.c. are sufficient to saturate seed oils. 



Solubility in Absolute Alcohol.— Neutral copra oil is the only fatty 

 oil which dissolves completely in two volumes of absolute alcohol at a temper- 

 ature of 32 deg. C, with the exception of castor oil, from which it can readily be 

 distinguished by other characteristics. 



Iodine Value.— No other fatty oil possesses such a low iodine value as 

 copra oil, namely, 9 per cent, of iodine. That of other vegetable oils varies 

 between 84 and 105. That is, therefore, a very important distinguishing test. 



Sulphuric Acid Saponification.— Maumene's process applied to copra oil 

 (at 17-18 deg.) gives good indications, as the temperature obtained exceeds those 

 of other vegetable oils by 50 deg. It is curious that this most distinctive test is 

 not generally used. 



Volatile Acids.— The determination of the volatile acids, soluble and in- 

 soluble, also serves as another test for the purity of copra coconut oil. 



Nitric Acid Test.— A simple agitation of the oil with an equal volume of nitric 

 acid at 40 deg. gives useful indications. Copra oil remains unaltered when it is pure 

 and clear, but becomes sensibly brown by the addition of 5 per cent, of seed oils. 



Sulphuric and nitric acids combined, employed in the proportions indicated 

 by Cailletet for the purity of olive oil, furnish most distinct indications with 

 copra oil. Now, thanks to these means of investigation, the analysis of copra oil 

 has been attended with success and its adulteration has greatly diminished, so 

 that it is usually only practised in small proportions, which consequently are 

 the most difficult to detect. For instance, with an admixture of 5 per cent, of 

 another oil, instead of 24'1 c.c. of soda, for saturating 5 grams of the fatty acids, 

 23"8 c.c. would be required, but as it is not impossible to meet with a pure oil 

 saturated by only 23 '8 c.c, a doubt would exist; nevertheless, the benefit resulting 

 from such, a mixture is still considerable, sufficient to tempt the unscrupulous. 



The special reactions -which characterize certain seed oils, will give, in such 

 small proportions, very faint indications or even none ab all when these oils have 

 been subjected to an apropriate chemical treatment. The test for arachis oil 

 will be particularly delicate, the crystallisation of a few milligrams of arachidic 

 acid takes place with difficulty in the whole mass. It may also be remarked 

 that these different operations are inconveniently long and minute when a rapid 

 report is required and is often indispensable ; a process, therefore, by which it is 



