to whether the season made any difference."

In these experiments similar observations and records are made as
previously, "under the three following circumstances, namely: while
taking tea as an ordinary drink, on the days immediately following the
leaving it off, and on other days when it was not taken."

"A third series, of four experiments, was also made during four fasts
of thirty-six hours each--two with water only, and two with tea to
drink.

"In the following particulars, all the three series so entirely
coincide, that the conclusions will be set down as general deductions
from the whole.

"Tea, in ordinary doses, has not any effect on the amount of carbonic
acid expired, the frequency of the respirations, or of the pulse."

Obviously, then, it is not with reference to the heat-producing
function that we can look upon tea as in any sense a nutriment; and if
it causes no saving of carbon, its effects must be sought in checking
some other waste, or in the less consumption of nitrogen. The pulse,
and hence the respiration, are unaltered; for the two great processes
of circulation and aeration of the blood are interdependent functions,
and have, in health, a definite ratio of activity one with the other.
As a nervous stimulant, tea in excess will, as we all know, produce an
exaltation of the action of the heart, amounting in some persons to a
painful and irregular palpitation. No such result seems to follow its
moderate use.

"The loss by perspiration is limited by tea." This seems, at first,
contrary to common experience, as the sensible perspiration produced by
several cups of warm tea is a familiar fact to all tea-drinkers. That
this effect is wholly owing to the warmth of the mixture, it being
drunk usually in hot infusion or decoction, was pointed out long since
by Cullen. Tea limits perspiration, perhaps, by the astringent action
of the tannin which it contains,--of which more hereafter. What is
saved by limiting perspiration? Water, largely; carbonic acid, in
considerable amount; ammonia (a nitrogenized substance;) salts of soda,
potash and lime, and a trace of iron, all in quantities minute, to be
sure, but to be counted in the aggregate of arrest of metamorphosis.

But the great fact which establishes tea as an arrester of the change
of tissue is, that its use diminishes remarkably the amount of nitrogen
thrown off by the excretions, specially destined to remove that
element, when in excess, from