\Vater of Eespiration. 427 



averaging 0.358. In experiment No. 73, the ratios are 0.329, 0.232, 0.218, 

 0.291, and 0.505, averaging 0.286. In experiment No. 75, the ratios are 

 remarkably constant, i. e., 0.330, 0.371, 0.311, 0.312, 0.366, 0.318, and 0.321, 

 averaging 0.331. The ratios for experiment No. 77 are somewhat larger, i. e., 

 0.327, 0.400, 0.606, and 0.651, averaging 0.454. With the series of experi- 

 ments with S. A. B., therefore, it would appear that there is a possible ratio 

 between the water of respiration and perspiration and the amount of drinking- 

 water. Nevertheless, it must be borne in mind that only on one day in all 

 the experiments with S. A. B. did the drinking-water consumed fall below 

 1000 grams. That there can be no definite ratio can readily be seen from the 

 fact that on the first day of experiment No. 73 when the subject drank 2082 

 grams of water, the water of respiration and perspiration was 684 grams, while 

 on the second day, with a very considerable increase in drinking-water (total 

 2747 grams), the water from the lungs and skin was actually lower, i. e., 636 

 grams. Furthermore, in experiment No. 71 on the third day, the amount of 

 water consumed was nearly twice that on the first day, while the amount of 

 water in respiration and perspiration was nearly 200 grams less. In the 

 shorter experiments, Nos. 79, 81, and 85, there was also in each instance a 

 decrease in the amount of water consumed on the second day over the first, 

 accompanied by an actual increase in the water of respiration and perspiration. 

 Considering all the experiments seven show an increase in the water of vapor- 

 ization on the second day. 



In general, the water of respiration and perspiration remains fairly constant 

 on the different days of the same experiment, there being a slight though per- 

 sistent diminution as the experiment proceeds. Frequently there is a parallel 

 diminution in the amount of drinking-water, but in certain instances, especi- 

 ally in the two cited above, the contrary is true. Since, therefore, there is 

 such relative constancy in the water of respiration and perspiration and such 

 wide variations in the amount of water consumed, it is obvious that the ratio 

 between the water vaporized from the body and the water consumed must show 

 marked fluctuations. 



It is difficult, therefore, to trace any relationship between the amount of 

 drinking-water consumed and the elimination of water-vapor. As a matter 

 of fact, since all of the experiments here compared were made under condi- 

 tions of rest, what is recorded as water of respiration and perspiration is practi- 

 cally confined to the water-vapor leaving the lungs and skin. 



The absence of any apparent influence of the amount of drinking-water on 

 the water of respiration and perspiration in these fasting experiments is in 

 accord with the observations of Laschtschenko, 105 who made a number of experi- 

 ments in a Pettenkofer respiration apparatus to study the influence of the in- 



105 Archiv f. Hygiene (1898), 33, p. 145. 



