While trying to find a topic for his doctorate, he first went to Naples to study under crystallographer Arcangelo Scacchi, who was senile by that time. Scacchi's condition led Vernadsky to go to Germany to study under Paul Groth. Vernadsky learned to use Groth's modern equipment, who had developed a machine to study the optical, thermal, elastic, magnetic and electrical properties of crystals. He also gained access to the physics lab of Leonhard Sohncke (Direktor, Physikalisches Institut der Universität Jena, 1883–1886; Professor der Physik an der Technischen Hochschule München 1886 -1897), who was studying crystallisation during that period.