270 NEW THEORY OF MIXED G&SES. 



by that exprefiion common liquids or folids. Thus we might 



have had a dozen gafes in our atmofphere inftead of three or 



four, all in the fame compafs, and each retaining the fame 



And one gas denlity it would have had alone. The heavier gas has no 



othe^wtuteve? more tendency to raife the lighter, than a quantity of mot has 



may be their in- to expel the air from its interfaces. If therefore Dr. Thomfon, 



•ravitier 6 C or aD ^ otner > can mew novv one fluid, vvhich is not difplaced 

 nor any way acted on by another, mould by its reaftion caufe 

 that other to move into a higher or lower ftation ; then the 

 mathematical world will be obliged to reconfider their doctrine 

 of ftatics. Till then I muft take the negative of the propofi- 

 tion, and conclude, that elaftic fluids of the greateft and lead 

 fpeciflc gravity imaginable, on the fuppofition I hold, will alike 

 take the Ioweft and the higheft flations, regardlefs of each 

 other ; or in other words, they will arrange themfelves in the 

 fame order as. if thrown into a complete vacuum. The great 

 difficulty refpecling the uniform difl'ufion of the gafes being 

 removed, I think on my hypothecs the other phenomena can 

 require no explanation to any perfon converfant in pneumatics, 

 and the chemical I will take one inftance : It may by afked, How does fulphuret 

 abforptionofany Q f p^^ aD ftracT: oxi^enous gas out of any mixture; lime 



fingle gas will r t> & J ' 



be the fame as if water, carbonic acid gas, &c\ &c. ? The anfwer is obvious t 



it were alone. Exaclly in the fame way as if the gas in queftion was the only 



one in the veifel, and the operation going on in a clofe veffel. 



3. it is contrary 3. GASES HELD TOGETHER BY CHEMICAL 



to faft that gales AFFINITY, ABSURD. 



are held together 



n i t y . On this head it will be proper to premife certain facts : 



For they mix I. When two gafes of different fpecific gravity, fuch as 



uniformly, and ox jg enoils anc j hidrogenous, are put into the fame veflel and 

 agitated; if they be fuffered to iland fome time after, they 

 flill continue uniformly mixed. 



they occupy the 2. They occupy the fame fpace before and after mixture ; 



iame fpace after ^t ^ Qw mea f ure of each put together occupy two rneafures r 

 the temperature and pre0'ure remaining the fame. Mr. Davy 

 feems to think this principle is not ftriclly true in regard to a 

 mixture of azotic and oxigenous gas ; but the deviation from- 

 it, if any, is extremely fmall. 



and they expand, 3. The compoffcid is fubjeft to the fame laws of rarefaction 



Ice. as before. ^^ condenfation as the limples. 



There 





