736 
DE. E. SMITH OH THE ACTIOH 
former slightly increased. The depth of inspiration was increased 4 cubic inches and 
6-2 cubic inches. 
Cocoa.~~K^iA\ 16 (6 exps.), Plate XXXVI. fig. 43, April 20 (6 exps.). 1 oz. of good 
cocoa, well boiled in 11 oz. of water, gave me on two occasions a maximum increase in 
carbonic acid of 1-92 gr. and IT gr. per minute, whilst Mr. Moul had on one occasion 
a maximum increase of -64 gr. There was a maximum increase of air of 27 cubic inches 
and 61 cubic inches per minute in myself, with an increase of 94 cubic inches in ISIr. 
Moul. The rate of respiration and pulsation was nearly unaffected in myself, but it 
fell in Mr. Moul. The depth of inspiration was increased 3-6 cubic inches and 5 - 1 
cubic inches in myself. 
Cqfee ieaves.—April 16 (6 exps.), Plate XXXVI. fig. 41, April 30 (5 exps.). Mr. Hax- 
BUKY of Plough Court kindly furnished me with a specimen of coffee leaves, from which 
a beverage is made in Sumatra. ^ an oz. infused in 10 oz. of boiling water gave me on 
two occasions a maximum decrease in carbonic acid of -84 gr. and -89 gr. per minute, and 
Mr. Moul had a decrease of 1T2 gr. per minute. There was a maximum decrease in 
the quantity of air inspired of 26 cubic inches and 51 cubic inches per minute in myself, 
and 160 cubic inches in Mr. Moul. The rate of pulsation and respiration, and the depth 
of inspiration, all fell in both of the inquiries. 
The foregoing experiments prove— 
1. That tea, coffee, chicory and cocoa are respiratory excitants, whilst coffee leaves 
depress the respiratory function. 
2. The uniformity in the direction of the results is exceedingly striking, whilst the 
degree of influence is to a certain extent variable. 
3. Tea is the most powerful, then coffee and cocoa, and lastly, chicory. 
4. The rate of respiration was sometimes a little increased and at others a little 
decreased, but the depth of inspiration was always largely increased. The rate of 
pulsation was usually slightly increased. 
5. With the addition of an acid the effect was somewhat lessened, and the rate of 
both functions was increased to a greater degree than with tea alone, 
6. The addition of an alkali also lessened the effect of tea, and a fixed alkali totally 
destroyed its influence. 
7. The action of acids and alkalies varies with the state of the system and in different 
persons. 
8. The addition of sugar and milk in the ordinary way increased the effect. 
9. Small doses of tea, frequently repeated, have much greater effect than the total 
quantity taken at once. 
10. Cold tea, and tea infused and kept twenty-four hours, has as much effect as when 
hot and recently made. 
11. Green tea has somewhat more influence than black tea, and particularly in 
lessening the rate and increasing the depth of respiration. 
