POLARIZING CRYSTALS. “After successfully creating artificial alkaloids, he collaborated with Jean-Baptiste Biot to determine that while plant-derived alkaloids were optically active, his artificial ones were not, further establishing a link between the action of molecules upon polarised light and their action upon the animal economy, and a firm line between natural and artificial products later taken up in the work of Louis Pasteur.”
https://www.tandfonline.com/doi/full/10.1080/00026980.2020.1867786