2 28 Experiments on the Pi'oditction of Air 



A like globe, with fresh spring-water and two peach- 

 leaves, exposed at the same time, furnished only -^ of a 

 cubic inch of air, which, on account of the smallness of 

 its quantity, I did not submit to the test of nitrous air. 



Experiment No. 31. 



September 8. Very fine clear weather, but rather 

 cold for the season. Three equal globes. A, B, and C, 

 containing each 46 cubic inches, were filled as follows, 

 and exposed in the sun from 9 o'clock in the morning 

 till half an hour past 4 in the afternoon, when they were 

 found to have produced air as under mentioned. 



The globe A, filled with water, which, by being pre- 

 viously exposed in the sun for several days, with pota- 

 toes cut in thin slices, had turned green, furnished -^-^ of 

 a cubic inch of air of 299 degrees, or i <3 -|- 3 ;z = i.oi. 

 N. B. This water, before it was put into the globe, was 

 strained through two thicknesses of very fine Irish linen. 



The globe B, filled with the same green potatoe-water 

 (strained as before), to which were added four middling- 

 sized peach-leaves, furnished ^\ cubic inches of air of 

 320 degrees, or i ^ -]- 4 ;z =: 1.80. 



The globe C, filled with fresh spring-water^ with four 

 peach-leaves, furnished -^^ of a cubic inch of air of 151 

 degrees, or which, proved with nitrous air, gave i ^ -|- 

 2 ;z = I-49- 



To ascertain the quantities and qualities of the airs 

 remaining in the different waters used in this experiment, 

 putting the globes separately over a chafing-dish of live 

 coals, and making the water boil, taking care to hold the 

 globe in such an inclined position as that the air separated 

 from the water might be collected in the upper part of 

 the globe, the airs produced were as follows : — 



