110 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



ing been infused several hours, and repeated every quarter of an 

 hour, for five doses, gave an average increase of 1.2 and a maximum 

 Increase of 1.8 grain per minute. The total increase, as shown by ten 

 observations, was no less than 193 grains; and at the close of the 

 experiment the increase continued at the rate of 54 grains per hour. 



"5. When 150 grains of black tea, infused in one pint of water, were 

 taken, and the whole carbonic acid was collected for 65 minutes, it 

 was shown that there had been an excess of 51.36 grains evolved, 

 which was not more than one-fourth of the total increase when the 

 tea had been divided into repeated doses. 



"6. When we took 100 grains of black tea, and the whole carbonic 

 acid was collected during 1 hour and 50 minutes, the total increase 

 was 70.40 grains. 



"2. As to the Volume of Air Inspired. 



"There was an average increase in the quantity of air inspired in 

 every experiment but one. Thus pursuing the order of the above 

 mentioned experiments, 

 In No. 1, the quantity was increased by 71 and 68 cubic inches per 



minute. 

 In No. 2, the increase was 34, 29, 50, 72, 95, and 26 cubic inches per 



minute. 

 In No. 3, the average increase was 120 and 50 cubic inches. 

 In No. 4, the average increase was 66 cubic inches. 

 In No. 5, the maximum increase was 92 cubic inches. 

 In No. 6, the average increase was 47.5 cubic inches. 



"3. As to the Depth of Inspiration. 

 "The rate of respiration either did not increase or was lessened; 

 and as the volume of air inspired was increased, the depth of inspira- 

 tion was greater so that the increased volume of air inspired at each 

 inspiration varied from 3 to 10.6 cubic inches. With this increased 

 depth, there was also a sense of greater freedom of respiration. 



"4. As to the Rate of Pulsation. 



"The rate of pulsation followed that of respiration, but in a less 

 degree, and was either not increased or was slightly decreased. 



"Hence it was proved beyond all doubt that tea is a most power- 

 ful respiratory excitant. As it causes an evolution of carbon greatly 

 beyond that which it supplies, it follows that it must powerfully pro- 

 mote those vital changes in food which ultimately produce the car- 

 bonic acid to be evolved. Instead, therefore, of supplying nutritive 

 matter, it causes the assimilation and transformation of other foods 



