180 



MEMOIR OF BR. D ALTON, AND 



l)lilogisticated air. According to Lavoisier, ICO grains of 

 nitrous air contain 32 grains of phlogisticated air, and G8 of 

 of dephlogisticated air. I am myself of the former philoso- 

 pher's opinion ; I likewise am of opinion, that every primary 

 particle of phlogisticated air is united to two of dephlogisticated 

 air, and that these molecules are surrounded with one common 

 atmosphere of fire." 



" To render this more explicable, let us suppose P to be an 

 ultimate particle of phlogisticated air, which attracts dephlo- 

 gisticated air with the force of 3 ; let a be a particle of 

 dephlogisticated air, whose attraction to P we will suppose 

 to be 3 more, by which they unite with the force of 6. The 

 nature of this compound will be hereafter explained. 



" Let us consider this to be 3 



the utmost force that can ^-^^ 



subsist between dephlogisti- 

 cated and phlogisticated air. 

 Let us suppose another par- 

 tide of dephlogisticated air b to unite to P, they will not 

 unite with the force of 6, but with the force of 4^ ; that is 

 the whole power of P, which is but 3, will be equally divided 

 and directed in two points 

 towards a and b ; so that P 

 and a b will unite with the 

 forces annexed to them ; for 

 the attraction of a and 6 to P 



meeting with no interruption, will suffer no diminution. 

 I consider to be the true state of 

 nitrous air. Let us now suppose 

 another particle of dephlogisticated 

 air c to unite to P, it will combine 

 only with the force of 4, whereby 

 a, b, c and P will gravitate toward 

 one another. Such is the state of 

 the red nitrous vapour or the red 

 nitrous acid. 



