The coffee bean mainly consists of irregular cells inclosed in very thick walls which are distinguished by uneven projections. The cells contain globules of oil. Most of the roots added to coffee exhibit a conglomeration of cells (provided with thin walls) and groups of jointed tubes, often quite similar to one another in structure. The microscopic appearance of some of the starch granules, occasionally met with in coffee mixtures, is represented on p. 100. Of 151 samples of ground coffee recently purchased at random and tested by various American chemists, 69 (45·7 per cent.) were found to be adulterated. FOOTNOTES: [9] Op. cit. [10] Pharm. Centralbl., 1885, p. 346. [11] Graham, Stenhouse and Campbell. [12] Leebody, ‘Chemical News,’ xxx. p. 243. [13] ‘Foods: Composition and Analysis.’ COCOA AND CHOCOLATE. Cocoa is prepared from the roasted seeds of the tree _Theobroma cacao_, of the order _Byttneriaceæ_. It sometimes appears in commerce as “cocoa-nibs” (_i. e._ partially ground), but it is more frequently sold in the powdered state, either pure or mixed with sugar and starch, and also often deprived of about one-half of its fat. Chocolate usually consists of cocoa-paste and sugar flavoured with vanilla, cinnamon, or cloves, and commonly mixed with flour or starch. According to Wanklyn, the average composition of cocoa is as follows:-- Per cent. Cocoa butter 50·00 Theobromine 1·50 Starch 10·00 Albumin, fibrine and gluten 18·00 Gum 8·00 Colouring matter 2·60 Water 6·00 Ash 3·60 Loss, etc. 0·30 R. Benzeman[14] has furnished the following averages of the results obtained by the analysis of cocoa and chocolate. The air-dried cocoa berries gave--husks, 13·00 per cent.; nibs, 87·00 per cent.:--