HISTORY OF THE ATOMIC THEORY. 



181 



This is the most 



" Let us again suppose a fourth 



particle of dephlogisticated air d 



to combine with P, it will unite 



only with the force of 3}. This, 



I think, is the state of the pale 



or straw coloured nitrous acid. 

 "Lastly, let us suppose a fifth 



particle of dephlogisticated air g, 



to unite to P, it will combine with 



the force of 3 3-5 ths, so that a, h, 



c, d and e will each gravitate to- 

 wards P as their common centre of gravity. 



perfect state of colourless nitrous 



acid ; and in my opinion no more 



dephlogisticated air can unite to 



the phlogisticated air, as hav- 

 ing its whole force of attraction 



expended on the particles of de- 

 phlogisticated air, a, 6, c, c/, e. 

 This illustrates the nature of 

 saturation. Thence we find that 

 dephlogisticated air is retained 

 with less force in the perfect or 

 colourless nitrous acid, than in 

 the straw-coloured, or in the red, 

 or in nitrous air." 



Page 194. " If the calcination of metals depended solely 

 upon their union to dephlogisticated air, it must be supplied 

 by water, when steam is brought in contact with them ; and 

 as every particle of light inflammable air is united but to a 

 single particle of dephlogisticated air, inflammable air must 

 be disengaged in proportion to the quantity of dephlogisti- 

 cated air which unites to the metals ; or, in other words, 

 according to the degree of calcination it acquires." 



