g(^ ON THE DOCTRINE OP MIXED GASES, 



to demonftrate to a cottager, that if he put a iieve-over his 

 chimney the fmoke would ilill efcape, though interruptedly ; 

 or to a chemift, that if he drilled holes in an exhau-fted re- 

 ceiver, it would in time be completely filled with air. 

 Ontheaftionof Mr. Gough next remarks upon my opinion, that the at- 

 aqueous vapour jjiofphere of aqueous vapour is fufficient to prevent the ocean 

 from efcaping into the air, which he fe«ms to think wonder- 

 ful : Upon this I may remind him of another wonderful fad, 

 which I confider the fame in effed ; that is, the pretTure of 

 like vapour on a cup of water in an exhaufted receiver, pre- 

 vents the water from efcaping out of the cup. When Mr. 

 Gough fhall explain how this fad is to be accounted for, I 

 may avail myfelf of his explanation to apply to the other. 

 He proceeds, however, to demonftrate the impoflibility of 

 an aqueous atmofphere ; but inftead of that, he demonftrates 

 the impojfibilit^ of an atmofphere of an^ kmd prejjing on water, 

 without at the fame time forcing the water up into its pores. 

 Luckily, as Mr. Gough obferves, the fads do not counter 

 nance the conclufion ; and therefore, however rigid the de- 

 monftration, it thews that the previous data are not corredly 

 alTuraed. The confideration of this fubjed is^ notwithftand- 

 ing, an important one ; it is more than a year fince I urged 

 iVlr. Goug^ to pay attention to it, and to attempt a folution. 

 of the ditficulty which perplexes all theories of the atmo- 

 fphere alike : I did it the rather, becaufe I thought him well 

 qualified for a fubjed of this nature, where the aid of ma- 

 thematical fcience muft be of fubfervience. The fubjed^ 

 has never been at all explained that I know of. I have 

 made an attempt w^hich has not yet been publithed, except 

 in a ledure laft winter ; but J (hall ftill be glad to avail ray- 

 More particular felf of any affiftance I can obtain. Suppoiing that in the 

 ftatementof thej^^gf^ ftratum of an atmofphere incumbent on water, there 

 tion.' ^" is one particle of gas for one hundred of water, (which may 



be the cafe, conlidering their relative deniities as one to a 

 thoufand) ; query, How does the air diffufe its pretlUre over 

 all the hundred particles equally, in fuch fort that no co- 

 lumn of particles of water is forced up into the interftices of 

 the atmofphere by the inequality of the prelTure ? If Mr. 

 Gough will explain this, either for. his new theory or for 

 any other, I will engage to remove all diflkulty on this 

 head which attaches to my hypothefis, 



Mr. 



