As a rule, coffee is not so prone to disorder the digestion as tea, but this is not universally true, and in some persons it always produces “biliousness.” When taken in excess, it produces—besides indigestion—palpitation, restlessness, irritability, sleeplessness, and a condition of general nervous prostration; in fact, similar symptoms to those produced by a prolonged over-indulgence in tea. While the consumption of tea is rapidly on the increase, that of coffee is steadily diminishing. This is partly owing to the greater expense of coffee—a larger quantity being required to form a good beverage; and partly to the greater difficulty in preparing good coffee. COCOA. Cocoa, or more properly cacao, is obtained from the seeds of the _Theobroma Cacao_—a native of the West Indies, Mexico, and the central parts of America. Its name Theobroma was given it by Linnæus, and means the “food of gods.” The fruit is a large leathery capsule, having nearly the form of a cucumber. It contains from 25 to 30 seeds, each about the size of an almond. Before using, these are roasted like coffee berries, and a peculiar aroma is developed in this process as in the case of coffee. The beans or seeds are then manufactured into three different products. (1) They are simply deprived of their husks and broken to pieces; this forms =Cocoa-Nibs=. (2) They are ground, husk and all, between hot rollers into a paste, and mixed with starch and sugar; this forms =Cocoa=. (3) They are shelled and then ground into a paste, as in making cocoa; sugar and some seasoning, usually vanilla, being subsequently thoroughly mixed; this paste is =Chocolate=. The purest form is the cocoa-nibs. When these are boiled in water, a brownish decoction is formed, with the fat as a scum at the top; this may be removed, and the decoction flavoured with milk and sugar. In this form, cocoa can be taken by invalids with weak digestion, who would be nauseated by the fat of ordinary cocoa or chocolate. The best cocoa is prepared as above; but the lowest quality contains the husks of the beans, with hardly any of the beans in it; a somewhat better, though still inferior sort, is made from the smaller fragments of the nibs, and a good deal of husk. In some cases the cacao butter is removed during the process of preparation, and starch or sugar substituted. This form is less likely to disagree with dyspeptics than whole cocoa. The action of the =Volatile Oil= (not the cacao-butter) developed during roasting, is probably similar to that of tea and coffee, though it is less =in amount=. The bitterness is greater than that of coffee, but the astringency less than in either tea or coffee. The =Concrete Oil=, or fat of cocoa, forms about half its weight. It is white, and not apt to turn rancid, and possesses an agreeable flavour. Cocoa also contains a certain amount of starch and cellulose.