Diagrams, crystal structures by William James Sell and William James Lewis Six pages of diagrams relating to crystal structures observed by Sell and Lewis in their investigations into a series of salts of a base containing chromium and urea. Subject: Chemistry / Crystallography Prints of these diagrams were published in volume 45 of the Proceedings of the Royal Society alongside the paper 'On a series of salts of a base containing chromium and urea.—No. 2'. 1889