and at a different time of year, so as to answer the question, which
might arise, as 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 aëration 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.