Water Vaporized from Lungs and Skin. 137 



Several years later, LikhatschefT, 1 working with the same respiration appa- 

 ratus, determined in a series of experiments with 2 individuals the quantity 

 of water vaporized from the lungs and skin in 24 hours. With one subject, 

 A. D. P., 24 years of age, weight 58.4 kilos, there were 775.5 grams of water 

 vaporized. With the same subject, with a body-weight of 58.2 kilos, there were 

 880 grams of water-vapor, and in 2 subsequent experiments with the same 

 subject, with a body-weight of 57.28 and 55.82 kilos, respectively, there were 

 collected 843 and 664 grams of water-vapor, respectively. In the last experi- 

 ment, A. D. P. fasted. With another subject, G. N. K., 24 years old, weigh- 

 ing 64.8 kilos, there were 1049 grams of water vaporized in 24 hours. In a 

 second experiment with this same subject, weighing 66.4 kilos, there were 

 805.5 grams of water vaporized. In none of these experiments are the data 

 presented in sufficient detail to permit a calculation of the relative humidity. 

 The temperatures were all not far from 20 C. 



Some of the most important researches on the water vaporized from the 

 lungs and skin have been made by Buhner and his associates. The majority 

 of their experiments were made for the purpose of studying the influence of 

 some special factor upon the water vaporized, such as the influence of humidity, 

 body-temperature, and, indeed, experiments were made with negroes to study 

 the possible effect of racial characteristics. From these experiments a number 

 can be selected giving data that are comparable with those here reported. 

 In studying 7 persons at rest, Wolpert 2 found that the hourly production of 

 water-vapor, calculated to a uniform body-weight of 70 kilos, varied from 30.9 

 to 70.9 grams; 4 of the 7 subjects vaporized from 56 to 60 grams of water 

 per hour at a temperature of 18 C, with a relative humidity of from 35 to 

 60 per cent. 



Studying a negro, Bubner 3 found that with a body- weight of 67 kilos at a 

 temperature of 26.4 C, the subject gave off 56.5 grams of water per hour. 

 The temperature was, however, somewhat above the temperatures in the experi- 

 ments here reported. 



Laschtschenko, 4 in Buhner's laboratory, studying the influence of the inges- 

 tion of water on the water-vapor elimination, made a number of experiments 

 at temperatures of 17 to 19 C. The relative humidity was from 25 to 55 

 per cent. In 4 experiments he ' found the water vaporized, calculated to a 

 body-weight of 70 kilos to he 30, 23, 20.8, and 28.2 grams per hour, respectively, 

 when no drinking-water was consumed. In 2 experiments when drinking-water 

 was taken, the water vaporized per hour was 21.6 and 30.5 grams, respectively. 



Schattenfroh, 5 in Buhner's laboratory, making respiratory experiments on 

 a fat man, 53 years old and weighing without clothing 95 kilos, found that at 



1 Likhatscheff, Production of heat by healthy man in the condition of comparative 

 rest. Dissertation (Russian), St. Petersburg, 1893. 



2 Wolpert, Archiv f. Hygiene, 1896, 26, p. 100. 

 s Rubner, Archiv f. Hygiene, 1900, 38, p. 133. 



* Laschtschenko, Archiv f. Hygiene, 1898. 33, p. 145. 

 5 Schattenfroh, Archiv f. Hygiene, 1900, 38, p. 93. 



