12. ANALYSIS OF 



ing ; when 1 found that, though the water had been 

 boiled ever fo !ono-, or ever fo often, air continued to be 

 produce! from it. 



In order to obviate the objection to the water ha- 

 ving imbibed the air from the atmofphere, in a fe- 

 cond procefs i put the water on which 1 operated into 

 long glafs tubes, over a column of mercury ; and after 

 producing air by keeping the upper part of the tube con- 

 taining the water a long time in the form of vapour, I 

 let out the air fo procured under mercury, by which 

 means the water never came into any contad: with the 

 air of the atmofphere, and yet it continued to yield air 

 whenever the procefs was repeated, without any per- 

 ceivable diminution, or limit. 



In the third procefs, no heat was ufed, but the water 

 was put into a glafs veffel confifting of a large bulb, 

 connefted with a tube the full length of a barometer, a 

 quantity of mercury fufficient to fill the tube being put 

 into it along with the water, and then inverted, and 

 placed in a bafon of mercury. By this means the prefTure 

 of the atmofphere was removed from the water, and thus 

 the air naturally contained in it efcaped, and lodged on 

 the furface of the water; and by inverting the veffel 

 again, it was thrown out into the open air. This pro- 

 cefs 1 kept repeating with the fame water more than a 

 year, and yet, as in the former proceffes, I found frefh 

 air always produced from it, and feemingly in an equable 

 manner. 



It has been faid that, in this procefs, the wate»^ de- 

 prived of all air, inftantly feizes upon fome the moment 

 that the newly extricated air is thrown out, the furface 

 of the water in the tube being then, though but for a 

 moment, expofed to the atmofphere. But this fuppofed 

 eager attradion of air by the water would have made it 

 to abforb the newly produced air, if not in its rarified 



ftate 



