William Higgins and John Dalton

Abstract

HIGGINS says several times that sulphuretted hydrogen is “a mere solution” or “suspension” of sulphur in hydrogen, and once that it contains nine particles of sulphur to five of hydrogen (pp. 78–81 of Higgins's book; the experimental results and the argument lead to the ratio nine particles of sulphur to five of hydrogen without any assumption about the weights of the atoms. The argument would occupy half a page of Nature). The idea and name of ‘equivalent’ were published by Cavendish in 1766 and 1788. I think Higgins deserves some credit for the Law of Multiple Proportions; but Berzelius said he did not state it and did not anticipate Dalton. Higgins's symbols did not anticipate Berzelius's; the letters do not always stand for elements and the same letter stands for different substances. Dalton put forward his theory in 1803 and gave a full account of it to Thomson in 1804, and what Davy said in 1809 seems irrelevant.