APPENDIX. EXPERIMENTS BY M. PAUL BERT. 441 



vers la fin, soit a cause du long repos dans la station assise, soit sous Tinfluence dc la 

 respiration d'un air suroxyge'ne. A cote de moi, un moineau et un rat se trouvaient 

 fort malades, et leur tempe'rature s'abaissait de plusieurs degre's. Quant a moi, bien 

 loin de courir un danger, je ne ressentais aucun des inconve'nients le'gers de la decom- 

 pression, ni I'c'tat nause'eux, ni le mal de tete, ni la congestion a la tete, et je n'en eprouvai 

 ])asdavant ige apres etre sorti de I'appareil. II me semblait meme que j'eusse pu aller 

 beaucoup plus bas encore, sans nul encombre, et j'y e'tais parfaitement dispose, si mes 

 pompes a vapeur, fatigue'es du travail, n'eussent refuse' d'e'puiser davantage I'air des 

 cylindres. Peut-etre dois-je en accuser la complicite des personnes presentes a I'expe'- 

 rience,qui venaientfie'quemmentme regarder atraversles hublots et, malgre I'aspecttout 

 a fait naturel de ma physionomie, semblaient fort efFraye'es de me A'oir expose' a cette 

 enorme diminution de pression. Elle correspondait, en efFet, a plus de 8800 metres, 

 c'est-a-dire a une hauteur supe'rieure a celle que les voyageurs en montagne et ks ae'ro- 

 nautes, hormis MM ('oxwel et Glaisher, aient pu atteindre encore. Je n'e'prouvais aucun 

 malaise a cette pression qui avait failli etre si funeste aux deux intre'pides Anglais, et a 

 laquelle devaient perir peu de mois plus tard MM. Croce'-Spinelli et Sivel. 



These experiments, as a whole, demonstrated that artificially-proditced 

 diminution of pressure caused effects similar to those v^^hich are experienced 

 by travellers on the earth, or in balloon^ at great elevations ; and that the 

 appearance of some of these effects may be retarded, or if they appear that 

 they may be temporarily driven away, by inspiring oxygen. They also 

 proved that one may descend with extreme rapidity from great heights 

 without injurious effects appearing immediately. In his experiment No. 256, 

 M. Bert made a descent, so to speak, of 15,000 feet in ten minutes ; and in 

 No. 257 he came down 17,400 feet in nine minutes, in each case, it seemed, 

 without taking any harm. 



Emboldened by the impunity which apparently could be enjoyed by the 

 use of this simple means, MM. Croce-Spinelli and Sivel, accompanied by 

 M. Gaston Tissandier, upon April 15, 1875, started iipon another aerial 

 voyage. The two former died at or about 28,000 feet above the sea, and 

 M. Tissandier narrowly escaped. In discussing what was the cause of the 

 death of these two unfortunates, M. Bert says (p. 1061) that the quantity 

 of oxygen they carried was insufficient for so high an ascent,^ and this may 

 have been the case ; but it is certain that the immediate cause of the cata- 

 strophe was not due to exhaustion of their supply, inasmuch as, when the 

 balloon reached earth again, there was a quantity of oxygen still remaining 

 in the hallonnets in which it was carried. 



The opinion of M. Bert was that no harm would have been taken if 

 these voyagers had imbibed more oxygen, and he appears to have imagined 

 that this was proved by the fact that he himself (while inhaling the gas) had 

 been able to sustain a pressure of 248 mm. ( r= 9 057 inches) for one or two 

 minutes. This experiment, however, proved no more than that he was able 

 to live for one or two minutes in air of about one-third the density of that 

 to which we are accustomed ; and there seems every likelihood, if he had 



1 "J'etais alors absent de Paris, et prevenu par une lettre de Croce-Spinelli de leur 

 prochain voyage, lettre dans laquelle il m'indiquait la qnantite d'oxygene ou'ils allaient 

 emporter (elle devait etre, je crois, de 150 litres), je liii fis rematquer I'insuffisance. 

 ' Dans les hauts lieux oil cette respiration artificielle vous sera indispensable, lui disais-je, 

 vous devez compter, pour trois hommes, sur une consommation d'au moins 20 litres par 

 minute; voyez comment votre provision sera vite epuisee.'" 



3L 



