178 MEMOIR OF DR. DALTON, AND 



light inflammable air, and that they are incapable of uniting 

 to a third particle of either of their constituent principles. 

 The above notions of water and vitriolic acid being strictly 

 kept in view, let us now proceed to inquire into the nature of 

 sulphur and vitriolic acid, and their various effects on different 

 bodies in the antiphlogistic doctrine. It has been already 

 observed that metals attract dephlogisticated air with greater 

 force than sulphur, and that sulphur attracts it with greater 

 force than light inflammable air. It has likewise been 

 observed, that vitriolic acid and water, mixed in a certain 

 proportion, will calcine metals with greater facility than 

 concentrated vitriolic acid, and that water will have very 

 little effect on metals in a common temperature. These facts, 

 though they may appear contradictory in themselves when 

 slightly considered, may be accounted for on the following 

 principles, and are, in my opinion, inexplicable by any other 

 means whatever." 



"Let us suppose iron or zinc to attract dephlogisticated air 

 with the force of 7, sulphur to attract it with the force of 

 6 7-8 ths, and light inflammable air with the force of 6 5-9 ths. 

 Let us again suppose these to be the utmost forces that can 

 subsist between particle and particle. That is to say, in 

 water dephlogisticated air is retained with the above force, 

 and likewise in volatile vitriolic acid, with the force already 

 mentioned. It is unnecessary to introduce here the aggregate 

 attraction which frequently preserves a neutrality between 

 bodies, as, for instance, between water and zinc, or water 

 and iron. Stating the attractive forces in the above propor- 

 tion, which I am led to believe is just from facts already 

 observed, we should imagine that iron or zinc would calcine 

 in water with greater facility than in vitriolic acid ; and if 

 some other circumstances did not interfere, it must be the 

 case. This the following will in some degree illustrate. 



Let S be a particle of sulphur, d a particle of dephlogisti- 

 cated air, which it attracts with the force of 6 7-8 ths, and let 

 the compound be volatile sulphureous acid; here the tie be- 



