26 



Composition of the Atmosphere 



Table 4. Percentages of oxygen in analyses of air made by Dalton. 



Date. 



1824 

 July 14 



July 14 

 Nov. 23 



1825 

 Jan. 8 



June 8 

 June 10 



Nov. 3 



1826 

 May 14 l 



May 14 



May 18 2 

 May 18 2 



May 18 



May 18 

 July 



1827 

 June 27 3 



June 27 

 July 2 



1828 

 Aug. 5 

 Aug. 5 



1831 

 July 4 4 



1832 

 July 26 



July 27 



1835 

 Aug. 21 B 

 Aug. 21* 

 Aug. 29 B 

 Aug. 29 6 

 Sept. 15 6 

 Sept. 15 5 



No. of 

 experi- 

 ments 

 averaged. 



4 

 6 



4 

 6 



10 



10 



6 

 4 



5 

 10 



7 

 8 



13 

 2 



4 



e 4 



4 



6 4 



4 



6 4 



Barom- 

 eter. 



28.0 



30.94 



29.90 

 30.30 



28.76 



26.20 



16.8 



Weather. 



Rain; wind SE., 

 strong. 



Following a week of 

 calm weather. 



Sunny and sultry; 



wind SW. 

 Rainy; wind SW... . 



Wind NE., light .... 



Place. 



Wind SW., light 



Rain and fog; wind 



SW. 



Summit of Helvellyn 

 (3000 ft.). 



Manchester 



Town air , 



.Do. 



...Do 



Field near the town 



Town air. 



Summit of Snowdon, 

 3570 ft. above the 

 sea. 



Country, 3 miles from 

 Manchester. 



Summit of Snowdon . . 



Second bottle from 

 Snowdon. 



Country , near Man- 

 chester 



Town air 



Summit of Helvellyn . 



Town air 



Balloon voyage over 

 Cheshire (9600 ft.). 



Town air , 



....Do 



Town air 



Summit of Snowdon . 



Summit of Helvellyn . 



Collected from balloon; 



altitude, 15,000 ft. 



(first phial) . 

 Town air 



Oxygen. 



Merde Glace, 6000 ft. 

 above the sea. 



Simplon Pass, 6174 ft. 

 Wengern Alps, 6230 ft. 



p. ct. 



20.70 



20.88 

 20.25 



21.12 



20.97 

 20.58 



20.6 



20.65 



20.8 



20.59 

 20.9 



20.7 



21.04 

 20.63 

 20.73 



20.7 



20.83 

 20.8 



20.92 

 20.44 



20.57 



20.59 



20.95 



(20.2 

 )19.4 

 \ 19.98 

 1 19.53 

 20.45 

 20.11 



1 Analyzed on May 28, 1826. 



2 Analyzed on May 25, 1826. 



3 Collected on June 26, 1827. 



4 Analyzed on July 21, 1831, or 17 days later. 

 s All analyzed in October, 1S35. 

 6 Duplicate. 



The explosion of hydrogen and air by the electric spark, as originally 

 proposed by Volta, had been the only method of uniting hydrogen and 

 oxygen in gas-analysis up to 1824, when Doebereiner 1 announced his dis- 

 covery of the catalytic action of platinum sponge. 



1 Doebereiner, Schweiggers Journal fur Chemie und Physik, 1824, 42, p. 60. 



