Rococo art and Enlightenment science, both of which flourished in Paris from 1710 to 1740, appear to have embodied two different sets of values. But the stylistic differences between them dissolve in their common concern with making and manipulating substances. Scientists at the Paris Academy of Science, especially René Réaumur and Charles Dufay, experimented on many of the same substances that artists used, often exploiting the same properties. Studying style and substance together brings out the connections between art and science and shows the value of respecting these two disciplines when writing their history.