he principle of tea (theine) is nearly identical with the
principle of cacoa--tea containing in 100 parts 29.009 of nitrogen. On
this subject Liebig has made an observation which I cannot avoid
noticing. He says, "We shall never certainly be able to discover how
men were led to the use of the hot infusion of the leaves of a certain
shrub (tea), or of a decoction of certain roasted seeds (coffee). Some
cause there must be, which would explain how the practice has become a
necessary of life to whole nations. But it is surely still more
remarkable that the beneficial effects of both plants on the health
must be ascribed to one and the same substance, the presence of which
in two vegetables, belonging to different natural families, and the
produce of different quarters of the globe, could hardly have
presented itself to the boldest imagination. Yet recent researches
have shown, in such a manner as to exclude all doubt, that caffeine,
the peculiar principle of coffee, and theine, that of tea, are in all
respects identical."--_(Anim. Chem.,_ pp. 178-9.) We really can see
nothing in all this but the manifestation of that instinct which,
implanted in us by the Almighty, led the untutored Indian (as we are
pleased to call him) to breathe into the nostril of the buffalo or the
wild horse, and by that single act to subdue his angry rage, or that
impelled the first discoverer of combustion to extract fire from the
attrition of two pieces of wood. The American Indian, living entirely
on flesh, "discovered for himself in tobacco smoke a means of
retarding the change of matter in the tissues of the body, and thereby
of making hunger more endurable."--(P. 179.) But the wonder ceases,
when we reflect that man was endued with certain properties by his
Maker which must have been at some remote period, of which we can form
no idea, active and manifest the moment he breathed the breath of
life. To inquire how he lost this property is not our business at
present, but it is only by supposing the _quondam_ existence of such a
property, active and manifest, that can in any way explain a first
knowledge of the therapeutic, or threptic, qualities of plants and
shrubs. With regard to the identity of theine, caffeine, theobromine,
&c., it would be as well that the reader should keep in mind that it
is so chemically _only_, for in appearance, taste, weight, odor, &c.,
no substances can differ more. Does the palate exert some peculiar
action on the in