 Dalton’s theory divided the chemical community and while he had many supporters, a considerable number of chemists remained anti-atomistic. Part of the reason for this was controversy surrounding the empirical application of Dalton’s atomic theory: How should one estimate atomic weights since atoms were such small quantities of matter? Daltonians argued that although such tiny quantities could not be measured absolutely, they could be measured relative to a reference atom (the natural choice being hydrogen as 1). This still left a problem in setting the ratio between the weights of different atoms in compounds. Dalton assumed that, if only one compound of two elements is known, it should be assumed that they combine in equal proportions. Thus, he understood water, for instance, as though it would have been represented by HO in terms of the formulas that Berzelius was to introduce (Berzelius, 1813). But Dalton’s response to this problem seemed arbitrary. Finding a more natural solution became pressing during the first half of the nineteenth century as more and more elements were being discovered, and the elemental compositions of more and more chemical substances were being determined qualitatively (Duhem 2002; Needham 2004; Chalmers 2005a, 2005b, and 2008).