Every reflecting man will admit that articles of such vast consumption as tea and coffee (amounting together to more than 343,500 tons annually), forming the chief liquid food of whole nations, must exercise a great influence upon the health of the people. There is scarcely any country in the world in which a dietetic drink or beverage resembling tea, is not prepared, and in general use, from some exotic or indigenous shrub. The two chief plants laid under contribution are, however, the Chinese tea-plant, and a species of holly peculiar to South America, producing the Paraguay tea. _Astoria theiformis_ is used at Santa Fe as tea. The leaves of _Canothus Americanus_, an astringent herb, have been used as a substitute, under the name of New Jersey tea. It has been a matter of surprise why tea should be so much sought after by the poorer classes, since by many it is looked on more as a luxury than of use to the human system. The manner in which it acts, and the cause why it is so much in demand by all classes, is satisfactorily explained by Liebig; and the benefit, therefore, which will be conferred by selling it at a low rate, and thus placing it within the means of all, has at last come to be duly appreciated. Liebig says, without entering minutely into the medical action of caffeine, theine, &c., it will surely appear a most striking fact, even if we were to deny its influence on the process of secretion, that the substance, with the addition of oxygen and the elements of water, can yield taurine, the nitrogenised compound peculiar to bile:-- Carbon. Nitrogen. Hydrogen. Oxygen. 1 atom caffeine or theine = 8 2 5 2 9 atoms water = -- -- 9 9 9 atoms oxygen = -- -- -- 9 __ __ __ __ = 2 atoms taurine 8 2 14 20 = 2 4 9 10 To see how the action of caffeine, theobromine, theine, &c., may be explained, we must call to mind that the chief constituent of the bile contains only 3.8 per cent. of nitrogen, of which only the half, or 1.9 per cent., belongs to the taurine; bile contains, in its natural state, water and solid matter, in the proportion of ninety parts by weight of the former, to ten of the latter. If we suppose these ten parts, by weight of solid matter, to be chloric acid, with 3.87 per cent. of nitrogen, then 100 parts of theine would contain 0.171 of nitrogen in the shape of taurine. Now this quantity is contained in 0.6 parts of theine, or 2 grains 8/10ths of theine can give to an ounce of bile the nitrogen it contains in the form of taurine.