lo Meldrum, Development of the Atomic Theory. 



them by the open-mindedness of the Editor of the Chemical 

 News. In Hfggins' case, as in Newland's, we find an idea 

 of extraordinary potency advanced by a man, who for 

 some reason or other, leaves the idea almost in the germ 

 and capable of infinite development by the efforts of 

 others. Moreover, it was not through Higgins and 

 Newlands that these ideas came to have an influence on 

 the progress of science. 



Granting the utmost that can be said on behalf of 

 Higgins, one must admit that Dalton made a great con- 

 tribution to the development of the atomic theory. Much 

 the superior of Higgins in energy of character and mind, 

 he made himself a prime factor in the development of the 

 theory by the persistency of his efforts to extend and 

 apply it in all directions, and to bring it into currency 

 amongst men of science. He applied it first to physical 

 and then to chemical phenomena. In opposition to 

 Berthollet's erroneous teaching regarding mixed gases and 

 the composition of chemical substances, he offered sound 

 ideas based on the theory. Again, he perceived, far more 

 clearly than Higgins, the practical consequences of the 

 combination of atoms. He never delayed putting his ideas 

 to the test of experiment. The test was often hastily and 

 crudely made, so urgently did he feel the necessity of 

 making it. No one can say that the chemical atomic 

 theory was accurately verified by Dalton, and no one can 

 deny that his table of atomic weights brought the theory 

 into touch with facts, and showed to all with eyes to see, 

 exactly what the theory meant. It has already been 

 shown, in the sixth paper of the series, that Dalton con- 

 verted Thomas Thomson to the theory, that Thomson 

 influenced William Hyde Wollaston, and Amadeo Avo- 

 gadro, and that Wollaston influenced J. J. Berzelius. 



