288 Historical 



The cold air drawn into the mouth might perhaps be warmed 

 quickly enough not to cause very considerable changes in temperature: 

 but as this air is very dry, there is evaporation of a certain quantity of 

 saliva, and therefore a chilling and a lowering of the temperature. 

 (P. 12.) 



Besides this quite general criticism, M. Forel rightly considers 

 one of the statements of MM. Lortet and Marcet strange and in- 

 explicable, unless we admit a serious mistake in the observation: 



Both say, in fact, that they had to observe the temperature 

 while walking, during the very act of ascent, for as soon as they 

 stopped, or merely slackened the speed of their progress, the ther- 

 mometer, relatively very low during the ascent, rose almost suddenly 

 to the normal body temperature .... 



Now the human body cannot grow warm so instantaneously. If 

 the temperature is assumed to be 35°, if the body weighs 60 kilograms, 

 60 calories must be produced for the temperature to rise to 36° .... 

 Helmholtz estimates the production of heat of a man weighing 60 kilo- 

 grams at 1.5 calories per minute; it would therefore take 40 minutes to 

 produce the 60 calories .... which is very far from the instantaneous- 

 ness described by Lortet and Marcet. (P. 15.) 



The first part of M. Forel's work ends with conclusions from 

 which I take the two following, which are the most important: 



1. The act of ascent normally produces an increase in body tem- 

 perature of some tenths of a degree; 



I reserve my opinion in regard to the effect of ascent upon the 

 heat production of the body in the condition known by the name of 

 mountain sickness. (P. 28.) 12 " 



These conclusions appear again at the end of the second part, 

 in which physicians and physiologists will read with the greatest 

 interest experiments investigating very exactly the determination 

 of the temperature in different parts of the body (hand, armpit, 

 groin, mouth, auditory canal, urine, rectum) . 



The third part is subsequent to the publication in the Annals 

 of the Natural Sciences of my Memoir, the results of which M. 

 Forel approves. In it is an anecdote which is very interesting 

 from the point of view of the theory which I have formulated, 

 and the accuracy of which the present work will show, I hope, to 

 those who are the hardest to convince; I shall relate it in the third 

 part of this work. 



Finally, M. Forel ends with a detailed account of an ascent of 

 Monte Rosa in which he experienced mountain sickness, although 

 only slightly. On this occasion he makes this remark, — which ex- 

 plains both certain exaggerations and certain doubts — namely, that 

 attention given to observation of the symptoms one feels dispels 



