Hummel was born in Lahr in the Grand Duchy of Baden. He studied astronomy, chemistry, mathematics and philosophy at the universities of Heidelberg, Freiburg im Breisgau, and Strasbourg. He simultaneously completed a degree in engineering at the Technical University of Karlsruhe. He later became a chemistry teacher at a high school in Karlsruhe and thus began his teaching career. In 1906, Hummel moved up to teach chemistry at a secondary school in Karlsruhe. It was not long after this that he began to put his knowledge of chemistry to practical use. From 1912 to 1914, he worked in a paint factory, Electra Werke GmbH.