File:Sample of crystals prepared by Edith Humphrey around 1900.jpg

English: Crystals of cis-bis(ethylenediamine)dinitrocobalt(III) bromide taken from the original sample in the Alfred Werner collection at the University of Zürich. The label on the display box is a facsimile of the original label from 1901. The compound and the crystals were prepared by Edith Humphrey of London in the course of her research and are first described in her Ph.D. thesis entitled "Über die Bindungsstelle der Metalle in ihren Verbindungen und über Dinitritoäthylendiaminkobaltisalze". Her work was undertaken around 1900 at the University of Zürich in the laboratories of Alfred Werner. Although not recognised at the time, the formation of enantiomorphic crystals in this way represented the first synthesis of optically active octahedral cobalt complexes.