Intelligence and Miscellaneous Articles. 473 



and maximum thermometers with an air-bubble and index specially 

 constructed by Baudin and which readily indicate the hundredth of 

 a degree. 



In proportion as we ascend from a low to a considerable altitude, 

 the disturbance of the physiological functions becomes greater and 

 greater. While it is scarcely perceptible in going from Lyons to 

 Chamounix (that is, from a height of 656 feet to one of 3444 feet), 

 it is very appreciable from Chamounix to the Grands-Mulets (3444 

 to 10,000 feet), more perceptible still from the Grands-Mulets to 

 the Grand-Plateau of Mont Blanc (from 10,000 to 12,897 feet); 

 lastly this disturbance becomes very appreciable from the Grand- 

 Plateau to the Bosses-du-Dromadaire (14,944 feet) and at the summit 

 of the Calotte of Mont Blanc (15,776 feet). We shall pass in re- 

 view the variations which the respiration, the circulation, and the 

 internal temperature of the body undergo at the different heights, 

 either during actual walking or after a suitable time of rest. 



Respiration.- — From Chamounix to the Grand-Plateau (from 3444 

 to 12,897 feet) the disturbances of the respiration are little marked 

 in those who are accustomed to the ascent of high mountains, who 

 hold the head down to diminish the orifice of the respiratory organs, 

 who merely breathe through the nasal orifice, and keep the mouth 

 shut, taking care to suck an inert body, such as a stone. From Cha- 

 mounix to the Grand-Plateau the number of respiratory motions is 

 scarcely altered ; we found twenty-four in a minute, as at Lyons and 

 Chamounix. But from the Grand-Plateau to theBosses and thence 

 to the top we observed thirty-six in a minute. The respiration is 

 short and obstructed ; it seems as if the pectoral muscles became 

 rigid, and the sides squeezed in a vice. At the top, after two hours' 

 rest, these inconveniences gradually disappear. The respiration 

 sinks to twenty-five a minute ; but it remains obstructed, and the 

 anapnograph shows that the quantity of air inspired and expired is 

 much less than on the plain. The air being under a very low pres- 

 sure, the quantity of oxygen brought in a given time into contact 

 with the blood is necessarily very small. 



Circulation. — During the ascent, although the pace was extremely 

 slow r , the circulation was enormously accelerated. At Lyons, in a 

 state of rest and while fasting, the mean number of the pulsations 

 was 64 in a minute. In the ascent from Chamounix to the top of 

 Mont Blanc this number gradually increases, according to theheights, 

 to 80, 108, 116, 128, 136, and finally, in ascending the last ridge, 

 which leads from the Bosses to the top, to 160 and more in a minute. 

 These ridges are, it is true, extremely difficult ; they have an inclina- 

 tion of from 45° to 50° ; but the pace was very slow, never more 

 than 32 paces in a minute, and frequently less. The pulse is 

 feverish, rapid and weak. The artery is felt to be almost empty. 

 Thus the least pressure stops the current of blood in the vessel. 

 The blood must pass with great rapidity into the lungs, a rapidity 

 which aggravates the bad oxygenation it already undergoes owing 

 to the rarefaction of the air. From 14,760 feet the veins of the hands, 

 the forearms, and the temples swell ; and every one, including the 



Phil. Mag. S. 4. Vol. 38. No. 257. Dec. 1869. 2 I 



