44. ORGANISM AND ENVIRONMENT 
assistant Coxwell in a famous ascent from Wolver- 
hampton in 1862. The balloon gradually reached a 
height of 26,000 feet, at which the oxygen pressure in 
the air was reduced to two fifths of the normal. 
Glaisher then first noticed that he could not read his 
instruments properly. Shortly afterwards his legs 
were paralysed, and then his arms, though he could 
still move his head. Then his sight failed entirely, and 
afterwards his hearing, and he became unconscious. 
Coxwell meanwhile endeavoured to pull the rope of 
the valve, but found that not only his legs, but also 
his arms were paralysed. He succeeded, however, in 
seizing the rope with his teeth, thus opening the 
valve. As the balloon descended Glaisher, about seven 
minutes after he lost consciousness, began to hear 
Coxwell’s voice again, and then to see him, after which 
he quickly recovered. The balloon had probably 
reached a height of about 30,000 feet. 
In another famous high ascent from Paris the three 
observers, Tissandier, Sivel and Crocé-Spinelli, were 
provided under Paul Bert’s direction with bags of 
oxygen to breathe from if they felt any ill effects. 
Though the oxygen would have saved them they were 
all paralysed before they realised their danger; and 
only Tissandier survived. The balloon, as shown by 
a self-registering barometer, had reached a barometric 
pressure of 263 millimetres, corresponding to a height 
of 30,000 feet, so that the pressure was reduced to 
nearly a third of the normal. 
The insidious effects of want of oxygen are per- 
haps still more strikingly illustrated in the case of 
