6 Clarke, The Atomic Theory. 



which the atomic h\'pothesis was strongly emphasised. 

 It was still, however, only an hypothesis, quite as 

 ineffectual as Swedenborg's attempt, and it led to 

 nothing. Dr. Higgins recognised seven elements : earth, 

 water, alkali, acid, air, phlogiston, and light ; each one 

 consisting of " atoms homogeneal," these being " impene- 

 trable, immutable in figure, inconvertible," and all 

 "globular, or nearly so." He speculated upon the 

 attractions and repulsions between these bodies, but he 

 seems to have solved no problem and to have suggested 

 no research. William Higgins, on the other hand, whose 

 work appeared in 1789, showed more insight into the 

 requirements of true science, and had some notions con- 

 cerning definite and multiple proportions. His concep- 

 tion of atomic union to form molecules was fairly clear, 

 but the distinct statement of a quantitative law was just 

 beyond his reach. In 18 14, however, when Dalton's 

 discoveries were widely known and accepted, Higgins 

 published a reclamation of priority.* In this, with much 

 bitterness, he claims to have completely anticipated 

 Dalton, a claim which no modern reader has been able 

 to allow. In Robert Angus Smith's "Memoir of John 

 Dalton and History of the Atomic Theory ,"f the work of 

 Bryan and William Higgins is quite thoroughly dis- 

 cussed, and therefore we need not consider the matter 

 any more fully now. We see that atomic theories were 

 receiving the attention of chemists long before Dalton's 

 time, although none of them went much beyond the 

 speculative stage, or was given serviceable form. They 

 were dim foreshadowings of science ; nothing more. 



* " Experiments and Observations on the Atomic Theory and Electrical 

 Phenomena." By William Higgins, Esq, etc., Dulilin, 1814. 



t Memoirs of the Lileraty and Philosophical Society of Manchester, 

 Second Series, Volume 13, 1856. 



