Alchemists believed that no transformation—whether in the laboratory, in the body, or in the soul—could succeed without the presence of a mysterious ingredient known as the Materia Prima (First Matter). Nothing was more important to alchemist’s work than this energetic essence, which they believed could be extracted from nature and rendered tangible and visible. This lecture examines the nature and properties of the elusive First Matter. Hauck explains how the concept of the First Matter evolved in both the scientific and Hermetic traditions to become a fundamental, although often unrecognized, tenet of both modern Hermeticism and modern physics. Based on a lecture at the “Hidden In Plain Sight” Conference at the Francis Bacon Auditorium in San Jose, California, in 2011. A video recording of this lecture with associated images is at https://youtu.be/_dQl1Z24sd0