DISCUSSION AND CORRESPONDENCE. 



213 



changes due to respirations are indi- 

 cated by sloping lines, the number in 

 each case indicating the net loss in 

 grams; that is, the difference between 

 the quantity of carbon dioxid and water 

 vapor exhaled and the oxygen absorbed. 

 All the vertical lines indicating sudden 

 decrease in weight are due to urine ex- 

 cept the two (on the second and fourth 

 days) which are marked 'feces.' 



Starting at 7 o'clock on the morning 

 of the first day with a weight of 68,420 

 grams, the subject loses 45 grams in one 

 hour by respiration. This loss by respi- 

 ration was determined to be 270 grams 

 in six hours, and in making up this dia- 



weight drops during the afternoon and 

 then supper brings it up to the maxi- 

 mum of the day. During the night the 

 weight falls again, so that at 7 o'clock 

 on the second morning it is almost ex- 

 actly the same as at the start. It is 

 noteworthy that the loss by respiration 

 is nearly as great during sleep as during 

 the morning and afternoon hours, there 

 being a loss of 254 grams in six hours 

 during sleep as compared with 270 in 

 six hours during the day. 



The variations in weight in the three 

 succeeding days can be followed from 

 the diagram. These diagrams were made 

 from the records of the experiment, and 



A.M. 



gram it was assumed to be uniform dur- 

 ing the six hours. The loss by carbon 

 dioxid is almost exactly 25 per cent, 

 greater than the gain by oxygen ab- 

 sorbed. Sitting on a good balance, one 

 can literally see one's self grow lighter 

 as one quietly breathes one's self away. 

 Breakfast adds 675 grams, respiration 

 reduces his weight by 110 grams up to 

 10.30, when a drink of water adds 200 

 grams; a further loss of 110.3 grams by 

 respiration is followed by a loss of 341 

 grams of urine, then 28 by respiration, 

 and at 1.30 dinner adds 804 grams. The 



the computed weights agreed quite well 

 with actual weighings made at several 

 different times during the experiment. 



Such diagrams have not as yet been 

 prepared for work experiments, but they 

 could not fail to be of great interest in 

 the cases we have been considering; 

 namely, where the subject of the ex- 

 periment does first positive work, then 

 negative work, and, finally, positive and 

 negative work together. 



Edward B. Rosa. 

 Wesley an University. 



