42 TEMPERATURE FLUCTUATIONS IN THE HUMAN BODY. 



Two curves are reproduced in fig. 14, showing records obtained in the mouth 

 with a clinical thermometer and with a thermal-junction thermometer. In 

 these curves the intervals of time during which the thermometer was held in 

 the mouth are expressed by horizontal distances, the corresponding tempera- 

 tures being represented vertically. 



Curve I may be of interest in showing that a clinical thermometer inserted 

 beneath the tongue does not attain its maximal temperature for a considerable 

 time. The curve was obtained in the following way: A subject carefully 

 trained to the use of a clinical thermometer, after preparing for the experiment 

 by keeping his mouth closed for perhaps 10 minutes, seated himself and placed 

 a clinical thermometer beneath the tongue, allowing it to remain for 15 

 seconds. He then removed the thermometer, read it, quietly shook it down, 

 and replaced it, this time for 30 seconds. This procedure was repeated, the 

 thermometer being kept in place during constantly increasing periods of time 

 up to 13 minutes. Even after the thermometer had been inserted 7 minutes, 

 a further rise of over 0.1 F. was noted; this, it would seem, must have been 

 caused by the slowness of the cavity in warming up, as the true body-temperature 

 must have been slowly falling on account of the quietness of the subject. 



Curve II was obtained shortly afterwards with the thermal junction; in 

 this case, however, the procedure was greatly simplified. The thermometer 

 was inserted at a definite instant and its temperature taken each minute by 

 means of the usual measuring apparatus. The curve is similar in shape to that 

 obtained with the clinical thermometer; the maximal temperature indicated 

 is, however, somewhat lower. 



Having obtained such inconstant results in the mouth with these two types 

 of thermometers, an attempt was made to find out if better comparisons could 

 not be obtained in the rectum. The experiment was accordingly tried of 

 inserting the thermal junction about 7 centimeters into the rectum, taking 

 readings for perhaps 15 minutes until constancy was assured, then removing 

 the thermometer and replacing it by a clinical thermometer inserted to the 

 same depth. The results given by the thermal junction varied from 0.1 F. 

 lower to 0.2 F. higher than the clinical thermometer. 



When the thermal junction and the clinical thermometer were fastened 

 together in a single rubber tube and inserted in the rectum, the maximal 

 reading of the thermal junction in one case was identical with that of the 

 clinical thermometer, while in another instance it was 0.2 F. lower than the 

 clinical thermometer. This pointed to an error in the thermal-junction reading, 

 but a further test was made which showed that the reading of the clinical ther- 

 mometer was by no means an indisputable standard. In this test, two 

 carefully calibrated clinical thermometers were inserted in a rubber tube and 

 placed in the rectum. After 10 minutes they were withdrawn, carefully 

 removed from the tube, and read. The readings were not identical, but 

 disagreed by 0.1 to 0.2 F. 



In order to make sure that the presence of the rubber tubing did not vitiate 

 the results, a thermal junction and a clinical thermometer were inclosed in 



