Intelligence and Miscellaneous Articles. 475 



Mont Blanc, however, where every one feels a little uneasiness, 

 more than half an hour elapsed before the thermometer attained 

 its normal height. These data cease to be true during digestion. 

 Then, in spite of the efforts which the ascent necessitates, the tem- 

 perature is maintained at about 36° or 37°, and even exceeds 37°*3. 

 The influence of the food does not last long ; scarcely half an hour 

 after having eaten, the body is again cooled. 



Whence arises this diminution of temperature ? In a state of rest 

 and while fasting man burns the materials of his blood, and the heat 

 developed is altogether employed in keeping his temperature constant 

 during the variations of the atmosphere. On a plain, and by mecha- 

 nical efforts, the intensity of the respiratory combustions, as Gavarret 

 has shown, increases proportionally to the expenditure of force. 

 Heat is transformed into mechanical force ; but from the density of 

 the air and the quantity of oxygen inspired, enough heat is formed 

 to compensate this expenditure. On a mountain, on the contrary, 

 especially at great heights and on very steep snowy ascents, where the 

 mechanical labour of the ascent is very great, an enormous quantity 

 of heat must be transformed into muscular force. This expenditure 

 of force consumes more heat than the organism can furnish ; hence 

 the body is cooled, and frequent halts must be made in order to 

 reheat it. Although the body be burning and in a state of perspira- 

 tion, it becomes cooler in ascending, because it consumes too much 

 heat, and the respiratory combustion cannot furnish a sufficient quan- 

 tity, owing to the small density of the air. It is this rarefaction 

 that causes less oxygen to enter the lungs at an elevated place than 

 on the plain. The rapidity of the circulation is also a cause of cool- 

 ing, the blood not having sufficient time to become properly charged 

 with oxygen. At a great height, as Gavarret has remarked, the 

 respiratory and circulatory motions are accelerated, not only in order 

 to render possible the absorption of a suitable quantity of oxygen, 

 but also to remove from the blood the dissolved carbonic acid. But 

 this gaseous exhalation, though very active, is no longer sufficient 

 to keep up the normal composition of the blood, which remains super- 

 saturated with carbonic acid ; hence the headache, sickness, sleepi- 

 ness which sometimes is almost irresistible, and the still greater cool- 

 ing which affects both travellers and guides, on reaching a height 

 of 13,000 or 14,000 feet. The mountain-sickness, which attacked 

 two of my companions very severely, is especially due to this con- 

 siderable cooling, and probably also to the blood being vitiated by 

 carbonic acid. During digestion the cooling becomes almost zero ; 

 hence the usage of the guides to eat about every two hours. Unfor- 

 tunately at great heights the want of appetite becomes usually so 

 great that it is impossible to swallow any food. 



The secretions exhibited nothing remarkable. The urine contained 

 neither sugar nor albumen ; but it was considerably diminished. — 

 Comptes Rendus, September 20, 1869. 



