Page:Popular Science Monthly Volume 58.djvu/221

Rh changes due to respirations are indicated by sloping lines, the number in each case indicating the net loss in grams; that is, the difference between the quantity of carbon [sic]dioxid and water vapor exhaled and the oxygen absorbed. All the vertical lines indicating sudden decrease in weight are due to urine except 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 respiration was determined to be 270 grams in six hours, and in making up this diagram it was assumed to be uniform during the six hours. The loss by carbon dioxid is almost exactly 25 per cent. greater than the gain by oxygen absorbed. 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 weight drops during the afternoon and then supper brings it up to the maximum of the day. During the night the weight falls again, so that at 7 o'clock on the second morning it is almost exactly 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 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 experiment does first positive work, then negative work, and, finally, positive and negative work together.