“In the first series of experiments, the daily allowance of food, though less copious on the tea days, was more nitrogenized, and nitrogen also was taken in as theine.  Yet, in spite of this, the quantity thrown off in twenty-four hours was nearly a gramme less than on the water days.  Still more strikingly is this shown in the days of complete fast, when pure spring-water is seen to cause a greater loss of nitrogen than infusion of tea, in spite of the supply of nitrogen contained in the latter.  The difference also is seen to exist in spite of an increased amount of bodily exercise.”

As final deductions from these experiments, there result, first, “that, when the diet is sufficient, the body is more likely to gain weight when tea is taken than when not”; second, “that, when the diet is insufficient, tea limits very much the loss of weight thereby entailed.”

A set of experiments made by Dr. Lehmann are parallel with these.  They exhibit the effects of coffee on the excretion of phosphorus, chloride of sodium, (common salt,) and nitrogen.  If less full than Dr. Boecker’s, they appear to be equally accurate, and more complete in showing the separate actions of the several constituents of coffee.  It would be tedious to the general reader to follow them in detail, and we shall avail ourselves of the brief resume of Dr. Chambers.

“First,—­Coffee produces on the organism two chief effects, which it is very difficult to connect together,—­namely, the raising the activity of the vascular and nervous systems, and protracting remarkably the decomposition of the tissues.  Second,—­that it is the reciprocal modifications of the specific actions of the empyreumatic oil and cafeine contained in the bean which call forth the stimulant effects of coffee, and therefore those peculiarities of it which possess importance in our eyes,—­such as the rousing into new life the soul prostrated by exertion, and especially the giving it greater elasticity, and attuning it to meditation, and producing a general feeling of comfort.  Third,—­that the protraction of metamorphic decomposition which this beverage produces in the body is chiefly caused by the empyreumatic oil, and that the cafeine only causes it when it is taken in larger quantity than usual.  Fourth,—­that cafeine (in excess) produces increased action of the heart, rigors, headache, a peculiar inebriation, delirium, and so on.  Fifth,—­that the empyreumatic oil (in excess) causes perspirations, augmented activity of the understanding, which may end in irregular trains of thought, restlessness, and incapacity for sleep.”

It follows that both the active elements of the coffee-berry are necessary to insure its grateful effects,—­that the volatile and odorous principle alone protracts decomposition,—­and that careful preparation in roasting and decocting are essential to secure the full benefits of it as a beverage.