Chemistry is typically considered to be a nomothetic science, i.e. a science interested in general laws rather than historical facts. Also, the unification of science is usually envisioned as an effort to connect particular scientific disciplines through their laws, e.g., the laws of chemistry are to be derived from the laws of physics. It is however equally sensible to combine the sciences through a single cosmic history. There is a large literature following this direction, albeit rarely focused on chemistry. In (...) this paper some ideas concerning the possible role of a 'historical' (or 'idiographic') chemistry are presented, with special attention to the notion of a 'genetic' classification of chemical compounds, and to the counterintuitive proposition that many major branches of physics may in fact be explained by chemistry, not the opposite. (shrink)