Keywords: Hessel.png en Some of Hessel's drawings from 1830 which were reproduced in 1897 My private collection Jnl chemist 1897 PD-old Geologists from Germany 1402 establishments 1796 births Alumni of the University of Heidelberg Educational institutions established in the 15th century Mineralogists from Germany University of Marburg faculty 1872 deaths Location not applicable Geometry diagrams |