DR. DALTON ON THE CONSTITUTION OF THE ATMOSPHERE. 
361 
Air taken in an Aerial Voyage over Cheshire. 
Mr. Grafton was so good as to procure me a bottle of air taken in an aerial voyage 
over Cheshire with Mr. Green, June 26, 1827 ; height 9600 feet above the sea*. The 
air was transferred into two phials. 
First Phial. 
June 2/. — Average of seven experiments of balloon air gave 
Average of seven experiments on town air gave . 
July 2. — Average of eight experiments of balloon air gave 
Average of eight experiments on town air gave . 
20*7 oxygen per cent. 
20-83 
20*2f 
20-8 
The second phial of balloon air was carefully preserved, the phial being filled and 
having a ground stopper. It was analysed. 
1 828, May 28. — Average of three experiments balloon air gave 
Average of three experiments town air gave . 
Aug. 5. — Average of thirteen experiments, being the 
whole of the balloon air, gave .... 
Average of thirteen experiments on town air 
gave 20*92 
20*70 oxygen per cent. 
20*80 
20*52 
On the last-mentioned day I received a bottle of air from the summit of Snowdon 
through the care and attention of my friend and pupil Mr. John Hall. It was 
corked and well sealed with wax ; when opened under water a due portion of that 
fluid entered. 
The average of the first two experiments gave 20*44 oxygen per cent. 
The rest of the air after these two experiments was divided into two portions, and 
entered into two phials for examination. These were analysed a week or two after- 
wards. 
Average of five experiments with first phial gave 20*25 oxygen per cent. 
Average of four experiments, which emptied the first phial, gave 19*98 oxygen per 
cent. 
Average of seven experiments of second phial gave 20*3 oxygen per cent. ; and a 
considerable portion was left. 
Average of the town air was during these experiments nearly 21 oxygen per cent. 
I am not aware of any cause why this air was so much inferior in oxygen to that 
on former occasions. 
* Height found as under : 
Capacity of bottle 10*47 ounces. 
On drawing the cork under water there entered . 2*77 ounces. 
Left . . . 7*7 ounces of air. 
Also height of barometer and thermometer below given. 
f The whole air in the first phial was spent in these fifteen experiments. The deterioration of the air in the 
first phial, by being kept half full of trough water for five days, is remarkable. 
