66 Historical 



vide oneself with colored glasses and veils so as not to add to fatigue 

 and breathlessness the vertigo which would no doubt be caused by 

 this immense winding-sheet of snow which surrounds one. 



We could note, moreover, that the physical sufferings attendant 

 upon such an ascent have been much exaggerated; none of us had 

 hemorrhages of any sort. . . . 



The Indians, used to this ascent, can carry an arroba (11 kilos) 

 and they ascend very rapidly. . . . 



We reached the summit of the volcano (the summit reached by the 

 travellers is the Espinazo del Diablo (5247 meters), and not the true 

 summit, the Pico Mayor (5450 meters). . . . The last steps are rather 

 difficult; the rarefaction of the air, becoming greater and g'reater, adds 

 still more to the difficulty of the ascent .... 



Hardly had we reached the summit than the difficulty in breathing 

 which afflicted us ceased to be felt, and our lungs were not oppressed 

 as long as we were resting. However, all of us could observe a certain 

 excitement, which increased in some of us to the point of a violent 

 headache; this excitement can be compared almost to a slight state of 

 intoxication; the blood circulates rapidly, and the pulse rate rises to 

 nearly one hundred per minute. (P. 194.) 



Besides Popocatepetl, in Mexico there is only the peak of Ori- 

 zaba (5400 meters) the ascent of which can bring on discomforts 

 and even symptoms. This happened to Von Muller 1 '"' and his 

 companions, September 2, 1856. 



The travellers passed the night at 3000 Spanish feet from the 

 summit: 



The consequence of a stay in such rarefied air were soon strongly 

 felt by all of us. Our respiration had become much deeper and more 

 rapid, a natural result of the diminished quantity of oxygen reaching 

 our lungs at each inspiration of this thin air. We all had violent head- 

 aches with feverish tendency. These symptoms could not surprise us, 

 because we were at an elevation greater than that of Mont Blanc. . . . 

 Although we were lying close together, with furs and rugs over us, we 

 were all shivering with cold and fever. The temperature was below 

 freezing. (P. 278.) 



The next day they wished to complete the ascent: 



The climb was extremely steep, so that in 25 steps, we mounted no 

 more than 8 to 10 feet: besides we had to stop after these 25 steps .... 



None of us had nosebleed or such symptoms during the ascent; 

 but we had severe congestion of blood in the head so that the whites 

 of our eyes were deep red. . . . All had violent headaches, and shook 

 terribly with fever. (P. 282.) 



A large company of American, English, and Mexican travellers, 

 including artists, engineers, and mere tourists, tried to reach the 

 summit of this peak in 1866. They did not succeed either. They 

 were much distressed by symptoms of which one of the company in 



