gig DOCTRINE OF MIXED GASES, 



nical mixture ; the component parts of which cannot be fe- 

 parated without the intervention of chemical agents, becaufe 

 the disjoined fragments of each gas will be prevented from re- 

 Exception to the uniting by their mutual repuKion. There is one exception, 

 however, to the general rule ; for when a liquid is found in a 

 mixture, the component parts will follow the law of their 

 fpecific gravities ; becaufe an inelaftic fluid is not a61uated by 

 an intnnfic repulfion, in all other cafes the gafeous fragments 

 will continue to be farther and farther fubdivided, and will con- 

 flantly aiTume a new arrangement from the fligheft agitations. 

 The conftituent parts of fuch a mixture exert their force in 

 perfect union ; and this circumftance diftinguifties it from Mr. 

 Dalton*s compound, the conftituent gafes of which prefs fe- 

 parately upon all furfaces. 

 Thetheoryap- The necelTary premifes being now fettled, it is time to try 

 gi^td to Mr. ^^^ ^j^g powers of the theory upon Mr. Henry's experiments. If, 

 meats, then, ten meafures of water, containing an equal bulk of car- 



bonic acid gas, be prefled by a column of the fame gas, equi- 

 valent in force to 30 inches of mercury, the fta'LC of the aque- 

 ous compound will remain invariable ; becaufe the fpring of 

 the gas in the water appears, by Mr. Henry's experiments, to 

 be equal to the fpring of the incumbent gas : therefore, fliould 

 a gafeous particle happen to efcape from the compound, an 

 equal particle, from the upper part of the veflel, will replace 

 it immediately. But if the incumbent carbonic acid be made 

 to give place to a mafs of common air of the fame elaftic force, 

 the furface of the aqueous compound will undergo no change 

 of preffure ; but the gafeous part of it, meeting with no repul- 

 fion from the column of air, will begin to form a mechanical 

 mixture with it, according to the theory. The parcels of the 

 carbonic acid will alfo remain diftindl, according to the fame, 

 after their efcape from the water ; and as a number of them 

 will be arranged on the furface dividing the two mediums, 

 they will form fo many obftacles to the difcbarge of their kin- 

 dred gas ; the egrefs of which will be conlined to the inter- 

 mediate compartments of eafier tranfmillion confifting of com- 

 mon air. The divifion of the furface between the two medi- 

 ums, into compartments of eafy tranfmiflion and impene- 

 trable pomts, ultimately produces a fort of equilibrium, which 

 affigns their refpedlive portions of the elaflic acid, to the gafe- 

 ous 



