Given that Pasteur owes his place in the pantheon of modern science not only to the germ theory of disease he invented but also to having pioneered an aggressively “demonstrative” style of experimental science, the relative lack of attention paid to his teaching at the Beaux-Arts is surprising. His tenure as the school’s first professor of “geology, physics, and chemistry” from 1863 to 1867 has mostly been treated biographically. Some scholars have tried to reveal “the artist beneath the scientist” by tying Pasteur’s teaching to his youthful ambitions as a painter; others have noted his friendships with artists and fascination with the Parisian salons; yet others have pointed to his use of visualizations in his early research on crystallography. But more fundamental historical questions about this episode remain to be asked. What were the institutional circumstances of Pasteur’s appointment at the famed art school? What does his novel approach to laboratory research have in common with contemporaneous attempts to reform the training of painters, sculptors, and architects? To what extent do his lectures signal an early theorization of the arts as elemental media?