84 THE ANALYST. AN ANALYSIS OF COFFEE LEAVES. BY OTTO HEWER, F.C.S. Read before the Society of Plcblic Analysts, on 19th February, 1879. A SUPLE of roasted coffee leaves, mdysed by W. Stenhouse (Phil. Mag., 4, vii., 21), contained 1.2 per cent. of theine, 2.1 per cent. of total nitrogen, and yielded 88.8 per cent. of extractive matter, the infusion possessing a taste as of tea and coffee combined.Having recently had a sample of the slightly roasted leaves, as used in Brisbaae, Australia, handed to me, I have examined them with the following results :- Moisture . . . . . . . . . . . . . . Theine . . . . . . . . . . . . . . . . Soluble nitrogeneus matter . . . . . . . . . . Soluble mineral salts . . . . . . . . . . . . Other extractive matter . . . . . . . . . . Insoluble nitrogenous matter.. . . . . . . . . Celluloso . . . . . . . . . . . . . . Chlorophyl, a d other insoluble non-nitrogenous snhrjttinces Insoluble minerd salts . . . . . . . . . . Total extractive matters . . . . . . . . . . Total ash . . . . . . . . . . . . . . Soluble . . . . . . . . . . . . Insoluble . . . . . . . . . . Smd . . . . . . . . . . . . Total nitrogen, by Bod& lime prooeas I I a .... .. . I .. *. .. .. .. .. .. ., .. a . I . 10.29 4.95 19.81 13.36) 100~00 30.16 8'82 ; of whioh is 3.83 0.42 8.02 per cent. 4-99 ; inoludingTHE ANALYST. 85 The infusion contained much caffe-tannio acid, as well as some tannin and The amount of theine found is remarkably small. The taste of the infusion, if it can be compared with anything, resembles that of a mixture of tea and tobacco, a taste invariably observed, as I was told by my informaat, by habitual consumers of the infusion.The leaves when burnt or roasted exhale a powerful d o u r of tobacco, and the vapours, when condensed on a glass plate, smell overpoweringly of tobacco juice, It is needless to add that the leaves were carefully examined with the microscope, and that they contained no particle of tobacco.The microscopic structure of the leaves presents nothing very remarkable, but the sheaths of the veins are most regularly undulated. Mr. J. Hughes said that, having lately visited Ceylon, where he saw Mr. Cotton who had sent a sample to one of the societies here, he was much interested in the andysis, Coffee leaves had already been prepared and exhibited with a view, if possible, for future use as a drink ; the infusion was something like tea, and under some circumstances might be used as a substitute by persons living in the country. It is rather strong but very refreshing, especially after a long walk or ride. glucose, the latter probably derived from the decomposition of the tannin, The stomata me small and numerous,