Paper, 'On a series of salts and of a base containing chromium and urea (No. 1)' by W J [William James] Sell Sell writes: 'Various compounds of urea with metallic salts and oxides have been described by Werther and Liebig. Some of these are suggestive of an analogy between urea and ammonia, while others seem altogether anomalous. The following account of some chromium compounds of urea may help to throw some light on the nature of such compounds, for they appear to show that a very definite base is formed by a combination of urea with chromium.' Annotations in pencil and ink. Subject: Chemistry Received 13 January 1882. Read 26 January 1882. Communicated by [George Downing] Liveing. A version of this paper was published in volume 33 of the Proceedings of the Royal Society as 'On a series of salts of a base containing chromium and urea. No. 1'. 1882