History of Air-Analysis 



35 



plete description of their eudiometer, and report 6 air-analyses made 

 from one sample of carbon-dioxide-free air, in order to show the accuracy 

 of the apparatus. The results obtained were 20.936, 20.940, 20.932, 

 20.960, 20.946, and 20.941 per cent of oxygen, the variation being 0.028 

 per cent. 



Table 12. Regnault's analyses of air collected in Paris. 



Date. 



1847. 

 Dec. 24 



Dec. 24 



Dec. 24 

 Dec. 28 



Dec. 28 



Dec. 29 

 Dec. 29 



Dec. 30 



Dec. 30 

 Dec. 31 



Dec. 31 

 Dec. 31 

 Dec. 31 



Dec. 31 

 Dec. 31 



Place. 



Oxygen. 



Balcony, College of 

 France 



.Do 



...Do 



Top of Pantheon . . . 

 Top of Pantheon 



(snow) 



Observatory, College 



of France 



Place de la Concorde 

 Observatory, College 



of France 



\ 



.Do 



184S. 



Jan. 

 Jan. 



Do 

 Do 



} 



Top of the Pantheon 



Choisy-le-Roi 



Esplanade de Vin- 



cennes 



. . ..Do 



Over a cornfield . 



$ 



of 



Court, College 

 France 



Observatory, College 

 of France 



p. ct. 



20.987 

 20.952 

 20.957 

 20.999 

 20.962 



20.963 

 20.956 

 20.939 

 20.953 



20.948 

 20.939 

 20.930 

 20.984 

 20.967 

 20.949 



20.959 

 20.966 



20.945 



20.947 

 20.980 

 20.992 



20.913 

 20.934 



Date. 



Place. 



Oxygen. 



1S4S. 

 Jan. 4 



Jan. 6 



Jan. 7 



Jan. 8 



Jan. 8 



Jan. 9 



Jan. 10 

 Jan. 11 

 Jan. 12 

 Jan. 12 



Jan. 13 



Jan. 14 

 Jan. 14 

 Jan. 15 



Jan. 15 

 Jan. 15 

 Jan. 15 



Jan. 15 

 Jan. 15 



Jan. 15 

 Jan. 15 



Observatory, College 



of France 



....Do 



....Do 



....Do 



Choisy-le-Roi 



Observatory, College 

 of France 



...Do 



....Do 



...Do 



Choisy-le-Roi 



p. ct. 



20.929 

 20.948 

 20.943 

 20.956 

 20.948 



20.981 

 20.948 

 20.957 

 20.963 

 20.947 



Observatory, College 20.970 



of France 20.968 



...Do 20.952 



Pantheon 20.953 



Observatory, College 



of France 20.986 



Versailles I 20.936 



....Do 20.922 



....Do 20.948 



.Do 



.Do 



.Do 

 .Do 



20.954 

 20.992 

 20.993 



20.998 



20.952 



It is to Regnault that we are indebted for the first extensive inter- 

 national investigation on the composition of the air. This carefully 

 planned cooperative investigation was in part disturbed by the political 

 differences in Europe during 1848, but in spite of the difficulties encoun- 

 tered, Regnault finally succeeded in getting together a large number of 

 samples, which he analyzed. 1 Air was collected in Paris and other parts 

 of France, in Berlin, Madrid, Switzerland, on the Mediterranean Sea, on the 

 Atlantic Ocean, in Ecuador, on the coast of Africa, in India, and on the 

 Pacific and Arctic Oceans, thus representing by far the most extensive 

 investigation on the composition of atmospheric air that has ever been 

 undertaken. Indeed, it may be stated that no subsequent investiga- 

 tion has approached it in completeness with regard to the geographical 

 collection of samples. Regnault made arrangements to have these sam- 



1 Regnault, Annales de Chimie et de Physique, 1852, 3d ser., 36, p. 385. 



