458 Mr. Clinton T. Dent [Feb. 15, 



of the symptoms — like those of mountain sickness — experienced. He 

 set down the limit of life as arriving when the air contains but 7 per 

 cent, of oxygen, the normal amount being 20 per cent. He was 

 therefore led to infer that by supplying oxygen the evil effects of 

 diminished pressure could be warded off. To carry a sufficient 

 supply of oxygen on the mountain side would be physically im- 

 possible. Mr. Whymper's experiences disprove M. Bert's theory, and 

 Bert's views received a further shock in the fatal balloon in which 

 MM. Croce, Spinelli and Sivel lost their lives, dying from asphyxia at 

 a height of about 28,000 feet, although they had a supply of oxygen 

 with them. M. Bert's researches have attracted much attention, but 

 the work of Geppert and Frankel published in 1883 really carried 

 the question as regards laboratory work a good deal further. And 

 here, I hope I may be pardoned, if I turn only for a moment to some 

 physiological details. Geppert and Frankel found that life could be 

 sustained, without supplying oxygen, at a far lower pressure, viz. that 

 of 180 mm. of mercury, equivalent to a height of 36,400 feet. Yet 

 more, they pointed out clearly that three distinct stages could be 

 observed — that of difficulty of breathing, paralysis, and lastly, uncon- 

 sciousness or coma. On the first and third much has been written. 

 But it is the second of these three stages — the partial paralysis — 

 which has received far less attention, that affects profoundly the 

 question from the mountaineer's point of view. Geppert and Frankel's 

 results seem absolutely trustworthy. They bear out, too, even 

 allowing for possible error in observation, the experience of those 

 who have ascended in balloons. Life unquestionably can be main- 

 tained at far greater elevation (i. e. at a much lower pressure) than 

 that of the highest mountain. In the pneumatic cabinet, two most 

 important factors do not come into play. No exertion is required 

 beyond that of breathing, and there is no lowering of temperature. 

 In high balloon ascents again no exertion is required of the lower 

 limbs. The same effects that are shown under diminished pressure 

 are also shown at greatly increased pressure. The circulation in the 

 portion of the spinal cord or marrow immediately concerned with the 

 innervation of the lower limbs becomes greatly disturbed. The partial 

 loss of power in the lower limbs is brought about in this wise. The 

 blood collects and stagnates at this portion. It has been stated, but 

 incorrectly, that the reverse condition is produced. The temperature 

 of all the extremities is greatly lowered, not only by the surrounding 

 cold but by change in the nerve centres themselves. The importance 

 of this disturbance to the mountaineer who seeks to attain the greatest 

 elevation on foot is obvious. Yet this, the most significant feature of 

 the problem from the climber's point of view, seems to have attracted 

 little attention. The practical effect of this partial paralysis must be 

 to render each step which involves the raising of the weight of the 

 body doubly or trebly as laborious as it would be at the pressure to 

 which the individual is naturally accustomed. It is certain, however, 

 that the effects can be completely recovered from, and this partial 



