PHYSICS OF THE GLOBE. 197 



ascents of peaks in the Himalayas in 1 862 ; and Lortel's "Phy- 

 siologie dn Mai des Montagnes" (1870). The preceding ob- 

 servers ascended mountains. The following: relate to balloon 

 ascensions : Gay Lussac and Madame Blanchard in 1804, both 

 of whom ascended to 7000 meters; Coxwell and Glaisher in 

 1882 ascended to over 9000 and probably 11,000 meters; 

 and Croce-Spinelli, Sivel, and Tissandier in 1875 ascended to 

 about 8600 meters. 



From all of these observations, Schyrmunski thinks best 

 to draw but few physiological conclusions, and prefers to rely 

 on experiments made by means of the air-pump. Of similar 

 experiments lie knows only those of Henslaw, Tabarie, Ju- 

 nod, and Vivenot; but in the memoir of the latter on the 

 Physiological Effects of Condensed Air, only two observa- 

 tions are quoted on the influence of rarefied air. He has, 

 therefore, conducted a rather extensive series of experiments 

 upon himself. In each experiment, he or his friends remained 

 in the pneumatic cabinet for two full hours. During this time 

 the rarefaction proceeded uniformly until, in forty minutes, 

 the greatest rarefaction was produced. The pressure then 

 remained constant for an hour, and was then, in about twen- 

 ty minutes, gradually restored to the prevailing atmospheric 

 pressure. The pressure was ordinarily reduced to about 300 

 millimeters, corresponding to an altitude of about 14,000 feet. 



He divides lus observations into two classes : first, in so 

 far as they relate to the general effect on the system, they 

 agree with the observations on mountains and in balloons. 

 The first symptom is a sensation of pressure in the ears; the 

 second symptom relates to the voice, which becomes husky 

 and feeble ; but whether this is an effect, of the rarefied 

 air on the vocal organs or the ear he cannot decide. Whis- 

 tling becomes very difficult, due to the altered expiration and 

 inspiration ; headache was very severe in the first experi- 

 ments, and continued for some hours after leaving the cabi- 

 net ; lassitude and inclination to sleep, and a sensation of 

 heat in the face; the lips turned bluish, the eyes burned ; flick- 

 erings and difficulty in fixing the sight; the respiration be- 

 came more and more frequent and superficial, until finally 

 the difficulty of breathing became very great, and the pulse 

 rose from 84 to 104 per minute. All these general symptoms 

 were most decided in the first experiments, and afterwards 



