I^g SUPPOSED CHEMICAL AFFINITY OF 



riple as it rifes in water; the fame muft be allowed when a 



veflel, containing a confiderable portion of elaftic fluid, isfud- 



denlyexpofed at fome furface to the atmofphere; in this cafe, 



the fluids muji operate upon each other for a few moments in a 



colIe6led Capacity, as in elaftic bodies; becaufe the difFufive 



or repulfive force by which they conftantly tend to difperfion, 



is comparatively flow in producing the ultimate effe6l, being 



in this refpefl exactly fimilar to chemical affinity, the operation 



gradually diminifliing as the effedt draws towards a conclufion. 



Feir the feparate Nothing more therefore can be inferred from the fa6ls above- 



"^Tr^'h"'^' n^^^ntio'i'id, than that gravity overpowers, and for a moment 



relative gravity obliterates the efFedt of that caufe which in other cafes flowly 



more fpeedily produces the difperfion of the fluid, whether it be attradlion, 



fion can take as commonly fuppofed, or repulfion, as I fuppofe. Chemical 



place. philofophers have not enquired fufficiently into the effects of 



expofing gafes in diflferent circumftances to the atmofphere ; 



all that we are ufually told is, that a jar filled with hidrogen 



and uncovered, lofes its gas in a few feconds ; but if inverted, 



it remains nearly pure for a confiderable time, &c. I find that 



a cylindric jar of 7 inches depth and Q,\ diameter, being filled 



with hidrogen, and inverted, lofes more than half of its gas in 



two minutes, and there is fo little left as fcarcely to explode in 



fiutthediffufion five minutes. If a tube, J 2 inches long and \ inch diam',^ter, 



is much fpeedierijg ^„gj ^^j^ hidrogen, and expofed in like manner to the at- 



than IS generally ** ' *^ 



taufht, mofphere, it will lofe half its gas in five minutes, and that the 



fame, whether it be held up or down or horizontal. Here we 

 fee efTefls that cannot be accounted for by gravity, that are 

 produced in oppofition to its agency, and where indeed it is 

 almoft obliterated by the aflion of fome more powerful caufe. 

 Let the advocates for the atmofphere being a chemical com- 

 pound attend to fiich fadls as thefe, and they will foon find 

 themfelves reduced to acknowledge that all gafes have the fame 

 ajjinity for one another, a pofition which their do^rine ulti- 

 Thc fafts, if mately tends to eftablifh. Indeed it is the fame with regard 

 nhy^wod/fccw *"*''' ^"'^ vapour, of water, ether, or of any other fluid; that 

 that it is the is, all kinds of ga? or mixtures of gafes, have the fame affinity 

 ^jrh'"^'T^~ for the fame vapour, and even a torriceliian vacuum poflefl^es 

 and even be j"^ the fame affinity as any of them, judging from the quantity 

 tweenagasand evaporated, and force of the vapour in a given volume. If 

 any one doubt it, he may eafily fatisfy himfelf by throwing up 



a drop 



