20 



Composition of the Atmosphere 



conditions. Although in the analyses of air collected by Gay-Lussac in 

 the balloon, the ratio of hydrogen to oxygen was erroneously taken as 

 2.04 to 1, von Humboldt and Gay-Lussac used in this research the correct 

 ratio, 2 to 1, which had but recently been established. In this paper von 

 Humboldt acknowledges his error in advocating so strongly the nitric- 

 oxide eudiometer in his contention with Berthollet a few years before. 



The analyses of the air were made on the day of collection, a sum- 

 mary of the results being given. 



Table 1. Results of a research on the composition of air, made with the Volta eudiometer, 



by Humboldt and Gay-Lussac. 



Weather conditions. 



Wind. 



Nov. 25 



Nov. 26 



Nov. 27 



Nov. 28 



Dec. 1 



Dec. 3 



Dec. 5 



Dec. 7 



Dec. 13 



Dec. 19 



Dec. 23 



10.6 



3.3 



1.6 

 1.3 



4.1 

 2.3 

 4.2 

 3.1 

 9.6 

 2.2 

 1.0 



Overcast 



...Do 



Fine rain 



...Do 



Overcast 



Cloudy; little rain 



Cloudy 



Rain 



Overcast 



Cloudy 



Frost 



Snow 



Fog 



Cloudy 



Rain 



Thick Fog 



Rain 



Overcast 



Heavy frost ; thick fog . 



E 



ESE 



Very strong, SW. to W, 



S 



SW 



SW 



W 



S 



SW 



E 



N 



N 



NNE 



E 



S 



SSW. 

 NE. 

 SE. . 



Oxygen. 



p. ct. 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 

 21.1 

 21.2 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 

 21.1 

 21.0 

 21.1 

 21.1 

 21.0 

 21.1 

 21.0 

 21.0 

 20.9 

 21.0 

 21.0 

 21.0 

 21.0 

 21.0 



The authors conclude that they have shown, first, that the atmos- 

 pheric air does not vary in composition; second, that there are 21 parts of 

 oxygen in 100 parts of air; third, that there are no noticeable amounts of 

 hydrogen present in the air. This investigation is the first extensive re- 

 search into the composition of the atmosphere employing the hydrogen 

 eudiometer, and the conclusions drawn by the authors are astonishingly 

 correct when it is considered that the research was carried out over a cen- 

 tury ago. That the errors in the apparatus were far greater than are 

 permissible in modern research, especially when such fundamental de- 

 ductions are to be made, should not in any way dim the brilliancy of the 

 work of these investigators. Subsequently, the method was to have exten- 



