<J()8 NEW THEORY OF MIXED GASES. 



" would arrange themfelves according to their fpedfic gra- 

 Farther explana- f vity." Now as I am pcrfuaded that no one acquainted with 

 (he principles of mechanical philofophy would have written 

 the above if he had underllood my hypothefis, it feems to call 

 Intended order from me a further explanation. I propofe, therefore, )Ji, To 

 flate in as clear a point of view as the fubjecl will admit, the 

 principles which IaiTume : 'Id, To (hew that the confequences 

 which I have deduced from them are legitimate, and particu- 

 larly that mixed elaftic fluids ought not to arrange themfelves 

 according to their fpecific gravity : and, 3d, To demonitrate 

 that the fuppofition of the gafes conflicting the atmofphere 

 being held in a flate of equal difFufion by chemical affinity, is 

 not only inconfiflent with the phenomena, but is completely 

 abfurd. 



1. PRINCIPLES ASSUMED. 



Principles af- 1. I take for granted that the particles of fimple (unmixed) 



fun ^u\ . , elaftic fluids repel one another with forces inverfely as the 



1. That particles . * ... 



of fimple elaftic diflance of their centres, the temperature being given. This 



fluids repei in- j s a mathematical deduction from the allowed facl, that the 

 verfely as their • , , . . r . , ~ 



diftance. lpace occupied by any gas is lnverlely as the compretling 



force : (See Newton's Principla, B. II. Prop. 23). The abfo- 

 lute difiances of the centres of fuch particles mufl vary accord- 

 ing to circum fiances, and cannot eafily be determined; their 

 relative difiances in a liquid and aerial flate fometimes may. 

 Mr. Watt has fhewn, that fleam of 212° and prefliire 28 in- 

 ches, is 1800 times lighter than water; confequently the dif- 

 tances of the particles of fteatn are to the difiances of the faid 

 particles in a liquid flate, as 12 to 1 nearly, in that particular 

 cafe. Vapor in the vacuum of an air-pump, at common tem- 

 perature, will have its particles about 4 times the diflance, or 

 48 to 1 . 



2. In mixed 2. I fuppofe that in mixed elaftic fluids the heterogeneous 



hetero eneous thC P articIes do not re P el one another at al1 at ruch diilances as 

 particles have no they repel thofe of their own kind; but that fuch particles, 

 diftant or gaze- w j ien brought into aclual contact (to ufe the common lan- 

 tut only that of guage), refill each other in all refpects like inelaftic bodies, 

 contaft, formerly y^ig j s the peculiarity of the hypothefis, and what appears'not 



called the refif- , r „ , J n , //_ ... r . r . 



tanceof impene-fo be generally underftood. It I may explain by analogy, the 

 trability. mo ft flriking will be found in magnetifm. Two like poles of 



thevi r fibieeffeab«i a g nets re P e ^ one another with the fame force whether any 

 •f magnetiiin. Other 



