Fire and Life: The Chemical Thought of Buffon

In this paper I try to show, in the first place, that Buffon’s chemical thinking was not anachronistic but in agreement with the chemistry predominant in France before the chemical revolution of Lavoisier took place. Secondly, I try to explain why Buffon assigned an oily character to the inorganic molecules that, for him, were requisite for the spontaneous generation of life. The study of Buffon’s chemical thinking allows us to see that it was part of the affinity theory, a very successful theory in the 18th century about the relationship among chemical elements. On the other hand, understanding Buffon’s chemistry helps us to understand why, for him, life appeared spontaneously from inorganic oily matter; this idea is connected with a tradition in chemical thinking that considered fire as active matter. This notion of fire was kept, though disguised, in the conceptions of sulfur principle (a substance considered oily) and of phlogiston (originally “oily earth”), and finally culminated in the idea of fixed fire, sustained by the French chemistry during the second half of the 18th century. For Buffon, fixed fire attracted free fire and thanks to the movement of this element, life originated.