Kloss was the son of a physician and studied medicine at Heidelberg and Göttingen, where he became one of the cofounders of the Corps Hannovera Göttingen. He practiced medicine in Frankfurt. He became a book collector, and gathered a fine collection of old manuscripts, purchasing entire libraries of monasteries. Obtaining Masonic degrees, he started collecting books referring to freemasonry. His extensive library of Masonic works is now at The Hague (Cultureel Maçonniek Centrum 'Prins Frederik').