8 Melurum, Developuicni of the Atomic Theory. 



II. Netv ton's Influence in the Eighteenth Century. 



In the last quarter of the eighteenth century a very- 

 remarkable attempt at an atomic theory was made by two 

 Irishmen, by name Bryan Higgins and William Higgins. 

 The object of the second and concluding part of this 

 paper is to show that the theory advanced by Bryan 

 Higgins and amplified by William Higgins can be under- 

 stood only when regarded as springing, under the peculiar 

 conditions of the time, from Newton's theory. These 

 conditions were (i) the knowledge, due to Priestley, of 

 different kinds of gases, and (2) the new light which 

 Lavoisier threw on chemical composition consequent on 

 Priestley's discovery of oxygen. 



The senior of the two men,'" Bryan Higgins (1737- 

 1820) was self-taught in chemistry, and his career proves 

 him to have been the best all-round man among the 

 English-speaking chemists of his day. His " Experiments 

 and Observations concerning Acetous Acid" (1786) is 

 a record of a very thorough investigation in the field of 

 organic chemistry, in the course of which he discovered 

 the substance acetamide. As a technical chemist his 

 reputation was wide. He spent about four years (1797- 

 1802} in the West Indies, investigating the manufacture 

 of Muscovado sugar and rum. He was a pioneer in the 

 practical teaching of chemistry, and gave instruction in 

 the subject for some twenty-three }-ears (1774-1797) in 

 his School of Practical CJieniistry in Greek Street, Soho, 

 London. His minor discoveries include that of the 

 musical note which can be got on burning a jet of 

 hydrogen in air (1777}. 



'* For fuller information regarding them, see Brit. Assoc. Rep., Dublin 

 meeting, 1908, p. 668, and New Ireland Review, 1910, n.s., vol. 32, pp. 

 and 350-364. 



