246 Dr. W. Marcet and Mr. R. B. Floris. An Experimental 



Determination of Oxygen consumed or absorbed. 

 130"427 litres of air expired (reduced) in 26 minutes. 



Per minute. 



C0 2 found 239-0 c.c. 



Surplus O absorbed 65'1 



304-1 x 1-4338 (weight of 1 litre of 0) 

 X 60 minutes = 26"! 62 grams absorbed per hour. 



104,486/26,162 = 3994 calories, corresponding to 1 gram O con- 

 sumed. 



The first set of experiments was undertaken in order to ascertain 

 whether in the course of an hour there is any variation in the heat 

 given out by the same person, and, with this object in view, the heat 

 emitted by each of us in turn was determined throughout the first 

 and second half-hours spent in the calorimeter. It was found neces- 

 sary to introduce a three-way cock into the tube delivering the water 

 from the melted ice into the flask ; this three-way cock diverted the 

 stream at will into one or other of two flasks hanging to the tubes 

 leading from the ice-holder. 



The results obtained were as follow : 



Calories in two half-hours in succession. 

 W. M. E. B. F. 



First Second First Second 



half-hour. half-hour. half-hour. half-hour. 



58,781 58,551 55,444 51,395 



53,230 50,939 49,216 52,445 



55,327 52,161 49,128 53,812 



59,947 62,177 48,037 48,914 



46,644 48,954 49,540 51,905 



_ _ 46,744 44,878 



Means 54,786 54,556 49,685 50,558 



Difference = 0'42 per cent. Difference 1'76 per cent, 

 decrease in second half- increase in second half- 



hour on first half-hour. hour on first half-hour. 



Total for the eleven experiments, 0*75 per cent, increase in second 

 half-hour. (Calculation from total figures.) 



Therefore, in the case of W. M., the mean of five experiments gave 

 a difference of only 0'42 per cent, in the calories emitted during two suc- 

 cessive half-hours, while, in the case of R. B. F., the mean difference of 





