================+=========+============ | | Refractive | Acid | index | value | in Zeiss’s | | butyrometer ================+=========+============ | | 46-47·8 Cacao butter |9·24-17·9| at 40° C. | | Oil of Almonds | — | 64-64·8 | | at 25° C. Sesame oil | — | 67-69 | | at 25° C. Earth-nut | | (Arachis) oil | — | 65·8-67·5 | | at 25° C. Hazelnut oil | — | — | | Cotton-seed oil | — | 67·6-69·4 | | at 25° C. Oleo-margarine | — | 48·6 | | at 40° C. Beef tallow | — | 49 | | at 40° C. Wax | 19-21 | — | | Paraffin | — | — | | Stearic acid | 195-200 | — | | Sebin | — | — | | Cocoa-nut fat | — | 35·5 | | at 40° C. The presence of cocoa-nut fat can also be shown by the etherification of the fatty acids with alcohol and sulphuric acid, when the characteristic odour of the ester of cocoa-nut acid occurs. Vegetable oils, such as almond, cotton-seed, arachidic, sesame and hazelnut oils, lower the melting point of the fatty acids and raise the iodine value. Sesame oil is easily detected by Baudouin’s reaction, yielding a raspberry coloration whilst pure cacao butter keeps a fine yellow or dark brown. It is possible to detect the presence of so minute a quantity as 1% of sesame oil, by means of Baudouin’s reaction. The following table, containing the analytical determinations of all fatty substances which can possibly be employed in the adulteration of cacao butter, will serve to facilitate reference to this subject.