718 
DE. E. SMITH OX THE ACTION 
4. The Milk Series, viz. new (cows’) milk, skimmed milk, casein, casein and lactic acid, 
lactic acid, sugar of milk and lactic acid, cream. 
5. Alcohols, viz. spirits of wine, brandy, wbisky, gin, rum, skerry and port wine, stout, ale. 
6. The Tea Series, viz. tea, green and black, hot and cold, in different quantities, and 
with acids and alkalies; coffee, coffee leaves, chicory, cocoa. 
7. Certain other nitrogenous substances, liz. gelatin, albumen, fibiine, almond- 
emulsion 
The immediate object of inquiry was the effect of these various substances over the 
carbonic acid and vapour exhaled, the quantity of air inhaled, and the rate of pulsation 
and respiration. The inquiry as to the amount of vapour exhaled was chiefly pui'sued 
in the experiments on alcohols. 
I shall describe the effect of these various substances in the order now given, and in 
order to avoid repetition shall reserve some general observations until the end of the 
paper. The whole of the detailed results, forming many sheets of tables accompanying 
this paper, are delineated on Plates XXXV. and XXXVI. 
1. The Starch Series. 
The general expression of the results obtained, is that starch does not excite the evolu- 
tion of carbonic acid, whilst the ordinary foods, containing starch uffth other suostances. 
as sugar and gluten, are powerful and enduring resphatory excitants. 
Arrowroot.— JmiQ 19 (7 experiments f). The purest starch which I could obtain was 
arrowroot. The effect of 600 grs., well cooked with water, was an average increase of 
only T54 gr. of carbonic acid per minute in myself, and '208 gr. in Mr. Moul (Plate 
XXXV. fig. 3). On another occasion, September 6 (6 exps.), 750 grs. gave me an average 
decrease of '08 gr. per minute. In the first inquiry there was an average decrease in the 
air inspired of 8 cubic inches per minute in myself, and an increase of 10 cubic inches 
in Mr. Moul, whilst in the last I had an increase of 5 cubic inches per minute. The rate 
of respiration was reduced in all the inquiries, whilst that of pulsation u as decreased in 
Mr. Moul 3 per minute in the first, and increased in myself 3 per minute in the last. 
When taken after a long fast, as described in my former paper, page 696, 500 gis. 
gave a maximum increase of '45 gr. of carbonic acid per minute. 
Starch, cfic.— June 14 (10 exps.). Starch, imperfectly washed from 4 oz. of wheat flour, 
and therefore associated with other substances, gave a maximum increase of 2 1 grs. of 
carbonic acid per minute in myself, and 44 cubic inches of air insphed. There u as a 
decrease in the rate of respiration, and a very slight increase in the rate of pulsation. 
When the starch had been much better washed, June 24 (/ exps.), Plate XXX^ . 
fig. 6, the increase in the carbonic acid was '52 gr., and 14 cubic inches of air mspiied. 
* It wiU be borne in mind tliat in this series of inquiries the amount of hydrogen consumed was not 
determined. 
•)? This expression means that 7 observations were made upon each of us (or l-t on both of us) at regular 
intervals during the continuance of this experiment. 
