1 76 MEMOIR OF DR. DALTON, AND 



are in the same temperature, and, of course, their atmospheres 

 of fire must be in size proportionable ; or else some other 

 repelling fluid must interpose. The size of the repelling 

 atmospheres of nitrous air thus considered, and likewise the 

 weaker attraction of the molicules of this air to dephlogis- 

 ticated air than that of the ultimate particles of phlogistic in 

 their simple state, it is surprising to me, with how much more 

 facility the former unites to dephlogisticated air than the 

 latter." % 



After speaking of the combustion of sulphur, he says, p. 35, 

 " A good many more facts might be urged on this subject ; 

 but, in my opinion, enough has been adduced to convince an 

 impartial reader that all the phenomema above recited are only 

 explicable by entirely leaving out phlogiston, and supposing 

 sulphur to be a simple subtance, whose ultimate particles 

 attract dephlogisticated air with forces inherent in themselves, 

 independent of phlogiston or concrete inflammable air, as an 

 alkali does an acid, or gold and tin mercury ; and likewise sup- 

 posing the combustion of sulphur to be as simple a process as 

 that of light inflammable air; that is, that there is no dephlo- 

 gistication, or formation of water, during the union of the 

 oxygenous principle to sulphur, as containing not a particle 

 of light inflammable air in its constitution. I have often 

 combined sulphur rendered perfectly dry, and dephlogisticated 

 air likewise, deprived of its water by fused marine selenite in 

 large proportion over mercury, and could never observe that 

 water was produced. Indeed it may be said that the volatile 

 sulphurous acid, which is always the result of this process, 

 may redissolve it ; but this is not very likely, when a small 

 portion of water will deprive it of its elasticity." 



" According to Mr. Kirwan, 100 grains of sulphur require 

 143 grains of dephlogisticated air to convert them into 

 volatile vitriolic acid ; but they require much more in order 

 to become perfect vitriolic acid. Highly concentrated vitriolic 

 acid contains two parts of dephlogisticated air, and one of 



