On the Union of Gases. 69 



pulslve sphere of another, the particles of any two (or 

 m'T.) elas'ic fluids v\il! arrange iheniselves at the greatest 

 P'>s.sible distanc. from each other. This, I think, would 

 bear issir- wj h mathematical demonstration, which is what 

 Mr, Daiton evidently shrinks from :— but I am almost sa- 

 tiaed with hypotheses, there are such shallow ones, and iu 

 vo^iie too:_vve need no more of them, til] those we already 

 have be more justly appreciated. 



I remain your obedient humble servant, 



Manche^rer, ^^^^^^ SCHOLES. 



Juue 24, 1808. 



^ In Mr. Dalton's new Treatise on Chemical Philosonhy 

 just pubiishid, ii appears to me, he assumes this principle, 

 Tnat two gases, each press. ng on the containing vessel, with 

 a K.rce as 1- tnju every panicle, and having no repulsive 

 action (.1) each other, the joint effect of this pressure will be 

 equal to the individual tfllci of a single gas with a similar 

 pressure of \-26 ; wfueh cannot be the case. For suppose a, 

 a repulsive force ^...1 has li.e po'.xer of extending a certain 

 quantitv of gas A, under a given piessuie, a certain space s; 

 anu s^pp„>e /•H,u>the. repulsive f-rce that has the pov^er of ex- 

 tending another quauiity of another gas B, under the same 

 p^e^,^ure, ihe same -^pace v ;— neiiher ..f ihe^e tuo forces can 

 exiend these gases to greater space than ? (tht contrarv is ab- 

 surd;. And these two gases will conjointly, if put together on 

 these principles, only occupy the same space s, \hat each 

 would mdividuailv. But the repulsive power of gases under 

 the same circumstances is as the space occupied : consequent- 

 ly, the powers of expansion in iwo gases w.th no repulsive ac- 

 tion <.n each other, cannot act conjointly, but must be equal 

 only to the expansion of a -ingle gas whose power is as great 

 as A.-ither of these supposed conjoined fbrces ; and, as it has 

 been generally inferred, two measures of gas combined on this 

 theory ought only to occupy the space of one before admix- 

 ture. Mr. Daiton admits, that if an equal quantity of two 

 gases he combined according to his principles, in one vessel, 

 the repulsion of their particles from each other, being 1-25 

 before admUturCj will afterwards become only !• ; but says 



^3 he, 



