98 Dr. W. Marcet. 



The Author, within 1 hour and 5 mins. after Luncheon. 



The experiments on Mr. Floris are made partly after luncheon and 

 partly between breakfast and luncheon. There are fifteen of the 

 former and twelve of the latter. The experiments after lunch show 

 more C0 2 expired than those made after breakfast, and considerably 

 more O absorbed, the figure for the mean volumes of oxygen absorbed 

 being 40*5 c.c. after luncheon, and only 22*4 c.c. after breakfast. 



If we now compare with each other the present series of experiments 

 made individually for each of us, it will be seen that in those undertaken 

 at a mean time of 2 to 2 J hours after luncheon, the ratio of O con- 

 sumed to C0 2 produced is all but exactly the same, these figures 

 being 0*839 in my case and 0*840 in that of Mr. Floris. Moreover, 

 if the whole of the experiments on Mr. Floris be taken into account, 

 including those after luncheon and after breakfast, the respiratory 

 ratio will be 0*862, which is all but exactly the figure I formerly 

 obtained for myself, 0*864 (means fasting and under food), and near 

 to the figure for a former assistant, 0*875, these results agreeing 

 closely with the ratio given by Messrs. Jolyet Bergonie et Sigalas, 

 0-864, and by Mr. C. Speck, 0*869. 



While in the experiments reported in my last paper, the volume 

 of oxygen consumed in a certain time was nearly the same for 

 each individual person (one excepted) under similar physical cir- 

 cumstances, in the present instance there is a variation between the 

 volumes of oxygen consumed, the extreme difference amounts in my 

 case to 47*6 c.c., in that of Mr. Floris to 30 c.c. per minute. More- 

 over, we no longer observe, as formerly, that the oscillations in the 

 figures for carbonic acid expired, and corresponding oxygen absorbed 

 vary in a measure inversely to each other. After giving the question 

 a full consideration, I have come to the conclusion that this is due 

 to the method of collecting the air expired. In the former experi- 

 ments this air was expired into a bell-jar perfectly balanced under 

 atmospheric pressure, while in the present instance the air was 



