30 Mr. William Henry’s Experiments on the 
“ In an exhausted receiver/’ that most ingenious philosopher 
observes, “ Pyrmont water will actually boil, by the copious 
“ discharge of its air ; and I do not doubt, therefore, that by 
“ means of a condensing engine, water might be much more 
“ highly impregnated with the virtues of the Pyrmont 
“ spring.”* 
Before describing my experiments on the effects of addi- 
tional pressure, in saturating water with gases, it will be necessary 
to state the results of others, that were previously expedient, to 
determine the quantity of each gas combinable with water, at a 
given temperature, and under the ordinary weight of the atmo- 
sphere. In a few instances, also, it was deemed proper to 
ascertain the influence of different temperatures, over the con- 
densation of gases in water. 
SECTION I. 
ON THE QUANTITY OF GASES ABSORBED BY WATER, UNDER THE 
USUAL PRESSURE OF THE ATMOSPHERE. 
In order to attain considerable minuteness in observing the 
proportion of gases absorbed by water, an apparatus was em- 
ployed, of which the following is a description. 
The vessel A (Plate I. Fig. 1) is of glass, about 2 inches 
diameter, and 4! inches long. It is graduated into cubical 
inches, and quarter inches; and furnished at the top with a 
brass cap, into which a cock a is screwed. To the lower aper- 
ture, a copper tube C is cemented, which is bent at a right 
angle, the leg nearest the vessel being carried downwards, and 
furnished with a cock h. B is a glass tube, of about ^ inch bore, 
* Experiments on Air, arranged and methodized, Vol. I. p. 51. 
