History of Air-Analysis 



65 



analyses in Berlin, substantiate the belief that the atmosphere has a con- 

 stant constitution up to an altitude of 4600 meters. 



In a private communication Professor Durig writes that in the two 

 expeditions in 1903 with Zuntz and in 1906 1 with Frau Durig and others, 

 he made over 100 analyses of air. The percentage of oxygen was always 

 between 20.87 and 20.96. On the Teneriffe expedition in 1907 he found 

 from 20.87 to 20.98 per cent limits almost exactly those experienced in 

 Vienna and on Monte Rosa. 



In describing his extremely accurate and ingenious gas-analysis ap- 

 paratus, Haldane 2 has published the results of a number of air-analyses. 

 Four analyses of the same sample of air gave the following percentages: 



The author concludes that 20.93 per cent may be taken as the true per- 

 centage of oxygen in pure air. 



Absorbing the oxygen from dry air by means of heated yellow phos- 

 phorus, Watson, 3 working in Guye's laboratory in Geneva, determined 

 the oxygen in air collected in Geneva and on some of the nearby moun- 

 tains. In describing his method, he includes a few preliminary results 

 which are given in table 48. 



Table 48. Analyses made by Watson of air collected in Switzerland. 



Source ot air. 



Laboratory, Geneva (alt. 300 in.) : 



July 11, 1910, 4 p.m 



July 12, 1910, 5 p.m 



May 19, 10 a.m 



Saleve (alt. 1300 m.), May 19, 10 a. m 

 Rochers de Naye (alt. 2045 m.) : 



May 19, 10 a.m 



May 19, 5 h 30 m a.m 



Oxygen. 



III. 



p.et. 



21.03 



1 Durig, Archiv fiir die gesammte Physiologie, 1906, 1 13, p. 213. 



2 Haldane, in The investigation of mine air, by Foster and Haldane, London, 1905, p. 

 113. See also, J. S. Haldane, Methods of air analysis, London, 1912, p. 44. 



3 Watson, Journal of the Chemical Society, August, 1911, p. 1460. 



