INGESTION OF WATER. 141 



criticized 1 and a duplication of the experiments has not resulted in 

 confirming his original observations, it is not possible to place much 

 emphasis upon his findings. 



Probably no factor makes direct calorimetry so difficult in a study of 

 the effect of food on the metabolism as does the ingestion of liquids, 

 which are almost invariably taken into the body at temperatures con- 

 siderably below or above the body-temperature. Water is usually 

 taken at a temperature below that of the body, while coffee, tea, and 

 thin extracts or soups are ordinarily taken at a temperature above. 

 The question of the temperature adjustment inside the body is therefore 

 somewhat important. While the rectal temperature gives a remark- 

 ably good indication of the average body-temperature, it is by no means 

 certain that the large amounts of heat required to warm a considerable 

 quantity of water from 10 C. to body-temperature may not seriously 

 disturb the temperature distribution. Indeed, in certain experiments 

 reported from this laboratory, 2 the ingestion of water produced a notice- 

 able change in rectal temperature. The experience of Rancken, in 

 Tigerstedt's laboratory in Helsingfors, 3 shows that the rectal tem- 

 perature, although instantly affected by the ingestion of cold liquids, 

 returns to its original value in about 30 minutes, indicating that the 

 equalization of temperature is rapid. In a recent series of observations 

 Stengel and Hopkins, 4 employing a thermo-couple, found that after the 

 ingestion of 120 c.c. of ice water the temperature of the stomach dropped 

 rapidly 1 to 14 C. and returned to normal in from 19 to 31 minutes. 



The experimental difficulties experienced by Lusk 5 when giving a dog 

 large amounts of water and meat just taken from an ice chest illustrate 

 very clearly the disturbance in the heat distribution and incidentally 

 the difficulties of determining the heat production by direct calo- 

 rimetry when a large amount of material is ingested at a temperature 

 considerably above or below that of the body. 



STATISTICS OF EXPERIMENTS. 



The effect of water-drinking was studied in this research in five cal- 

 orimeter experiments and six respiration experiments. The experi- 

 ments with the respiration calorimeter at Middletown, Connecticut, 

 consisted of two 8-hour observations in which large amounts of water, 

 1,584 grams and 3,935 grams, respectively, were taken by the two 

 subjects. (See tables 69 and 70.) With the chair calorimeter in Boston 

 three experiments were made in January 1911, in which approximately 

 1,800 grams were taken by each subject. (See tables 71 to 73.) In the 

 shorter observations with the respiration apparatus six subjects were 



Benedict and Emmes, Am. Journ. Physiol., 1912, 30, p. 197. 



'Benedict and Slack, Carnegie Inst. Wash. Pub. No. 155, 1911, p. 73. 



'Rancken, Skand. Arch. f. Physiol., 1908, 21, p. 161. 



4 Stengel and Hopkins, Am. Journ. Med. Sci., 1917, 153, p. 101. 



5 Lusk, Journ. Biol. Chem., 1915, 20, p. 555; see especially pp. 558, 576, and 615. 



