Tea and Coffee have hardly any other properties in common than the possession of an alkaloid called _Theine_ or _Caffeine_, which is identical in the two. Chocolate contains a peculiar alkaloid called _Theobromine_. Paraguay tea or “maté” is the only other substance extensively used as a dietetic infusion that contains _theine_; in South America it occupies the same position in domestic economy as Chinese tea does in this country. Case 46 exhibits the chemical analysis of a pound of ordinary good Chinese Tea; and in Cases 47, 48, and 99, contiguously placed, are numerous samples of tea from China, Japan, Java, Brazil, and East India. The analysis of a pound of Coffee is shown in Case 50; and many samples of raw coffee from various parts of the world are exhibited. The visitor’s notice is directed to the printed descriptive label concerning Coffee, which is suspended near the case containing the analysis. _Cocoa_ is represented by the analysis of a pound of Cocoa paste in Case 53, and by a series of the fruit pods containing the seed or nuts, presented by Messrs. Fry and Son, of Bristol, as well as by various preparations and confections. The distinguishing feature of its composition consists in the large quantities of fat and albumen which it contains; so that Cocoa not only acts as an alternative through its _theobromine_, but as a force-producing and flesh and force-producing food. Samples of the commercial varieties of the nuts or seeds from various countries are exhibited. TEA AND COFFEE SUBSTITUTES. A variety of substances are exhibited in Case 49 in illustration of the use of the leaves of various plants for making potable infusions. The most important is Paraguay tea or “maté,” which contains the same alkaloid called _theine_, as the Chinese tea plant. A quantity of “maté” is shown, with calabash or dried gourd for making the infusion, and sucking pipe for drinking it. A large number of substances have been employed from time to time as substitutes for Coffee, and prepared in the same way. Many of them are shown in Case 52. In this country none of these so-called Coffee Substitutes have established themselves in public reputation, and are seldom sold. Some of them, however, are used as adulterants of Coffee. TOBACCO.