Page "John Dalton" Paragraph 17

The extension of this idea to substances in general necessarily led him to the law of multiple proportions, and the comparison with experiment brilliantly confirmed his deduction.

It may be noted that in a paper on the proportion of the gases or elastic fluids constituting the atmosphere, read by him in November 1802, the law of multiple proportions appears to be anticipated in the words: " The elements of oxygen may combine with a certain portion of nitrous gas or with twice that portion, but with no intermediate quantity ", but there is reason to suspect that this sentence may have been added some time after the reading of the paper, which was not published until 1805.