330 Dr. Marcet on the Temperature of the Human Body at 



these experiments the greatest care was taken to keep the bulb 

 of the thermometer as far back as possible beneath the tongue, 

 while the margin of that organ was applied firmly against the 

 lower jaw, the lips being kept closed, so that respiration was 

 entirely effected through the nose. It was, consequently, im- 

 possible that any of the air used for breathing could come into 

 contact with the bulb of the thermometer while these observa- 

 tions were carried on. 



The questions which offered themselves for investigation re- 

 lated (1) to the influence of various degrees of altitude on animal 

 heat, the body being in a state of rest ; (2) to the influence of 

 the act of ascending on animal heat observed at different heights ; 

 and (3) to the influence of the act of descending on the tempe- 

 rature of the body. I shall limit myself, on the present occasion, 

 to the first two questions, leaving the influence of the act of 

 descending on animal heat for future consideration. 



I soon ascertained the necessity of taking the temperatures 

 while actually engaged in climbing; accordingly this was done. 

 The instrument was withdrawn from its case and introduced 

 under my tongue; the looking-glass was removed from the 

 pocket, together with my watch ; and the height of the thermo- 

 meter was observed while in the act of ascending, and taking 

 every care to slacken my speed as little as possible. 



I began by noticing that frequently, while ascending, the 

 thermometer after a sufficiently long exposure showed a tempera- 

 ture which, though steady at the time, commenced rising shortly 



as nearly as possible on the model of that which I had used, gave the fol- 

 lowing results ; the bulb was kept under the tongue, and the degrees read 

 off with a looking-glass :— 



Temperature, 

 minutes. 



I. After an exposure of 1 36'2 Centigrade. 



» „ 2 36-5 



>} >> 3 36*7 



4 ... f 36-8 



5 36-8 



„ „ G steady at ... . 36*9 



7 36-9 



8 36-9 



II. After an exposure of 2 36*4 



Next day under the ) „ x „_ 



same circumstances, j 5 ' * ' ' d64) 



3|„. 367 



4± 36-8 



>, „ 5| steady at ... . 36*9 



6| 3G-9 



7± ,.. 36-9 



