220 BALLOON SICKNESS 



Everything became dark before him, and he lost consciousness for 

 a minute or two, till aroused by Coxwell. In the fatal ascent of 

 the "Zenith" to 8600 m. Croce Spinelli and Sivel died, while 

 Tissandier became unconscious. 



"At 7500 m.," Tissandier wrote, " the numbness which comes 

 over one is extraordinary. Body and mind grew gradually, 

 imperceptibly weaker without our becoming aware of the change." 

 " Presently I wished to take hold of the oxygen tube, but found that 

 I could not raise my arm. My mind was, however, still quite lucid. 

 I kept my eyes fixed on the barometer. I tried to call out ' We 

 are 8000 m. high,' but my tongue was as though paralysed. 

 Suddenly my eyes closed and I fell down like a log, completely 

 losing consciousness. It was about 1.30 P.M. At 3.30 P.M. I 

 reopened my eyes, feeling dazed and exhausted, but gradually my 

 mind grew clear. The balloon was descending with frightful 

 rapidity. My two companions were cowering down in the car, 

 their heads hidden under their travelling rugs. I gathered all my 

 strength together and tried to raise them. Sivel's face was 

 cyanosed, his eyes dull, his mouth open and filled with blood. 

 Croce's eyes were half closed and his mouth covered with 

 blood. . . ." 



Zuntz and v. Schrotter have twice ascended to about 5000 m. 

 In their first ascent Schrotter suffered from headache and a 

 peculiar vertigo, and found it difficult to read the experimental 

 observations. A few respirations of oxygen restored him. 

 Aeronauts do not, as a rule, suffer much before an altitude of 

 6000-7000 m. is reached, because they are not called upon to 

 execute strenuous muscular work in the car. 



It is probable that aeronauts have often suffered from CO 

 poisoning due to the coal-gas used to inflate the balloon. The 

 dissociation curves of CO and OHb show that as little as O'Ol 

 per cent. CO (measured at C. and 760 mm. 1 ) in the air would 

 affect a shallow breather whose alveolar 2 tension may sink to 

 40 mm. at 4000 m., while a deep breather would be affected by 

 this amount at 6000 m. An equal weight of coal gas escaping 

 in a dwelling in a town on the Andes must be more dangerous 

 than on the plains. 



1 Since the CO tension goes down as well as the Oo tension, a given per- 

 centage of CO, measured at say 400 mm., would be no more poisonous than 

 the same percentage measured at 760 mm. (Haldane.) 



