Although organic chemistry at his most active period as an investigator was experiencing an extraordinary development, and offering limitless opportunities of discovery, its problems then, and, it may be added, at no subsequent time, had more than an academic interest for him. The only communication dealing with organic chemistry with which his name is associated is a short note on the Spontaneous Polymerisation of Volatile Hydrocarbons contributed to the Chemical Society in 1885.[4] The paper had its origin in a chance observation brought to his notice by a tar-distiller, who had noticed the formation, on standing, of a white crystalline mass among the volatile hydrocarbons resulting from the decomposition of phenolic substances at a red heat. The crystalline substance was found to have a molecular formula C₁₀H₁₂, but its real nature and the mode of its genesis were not established. Organic chemistry was hardly taught at Heidelberg in Roscoe’s time, and then only by subordinate professors and _privat-docenten_, mainly to pharmacists. The effect of this training was seen in the subsequent character of his teaching. The lectures on organic chemistry that he was necessarily required to give at Owens College, with their limited possibilities of experimental illustration, simply bored him. Happily he found in Schorlemmer a colleague who was glad to relieve him of the duty. Schorlemmer was not a fluent speaker, and although he wrote our language with ease and accuracy, he never acquired familiarity with the mysteries of its pronunciation. But he was an excellent teacher, remarkably well-read, and had an astonishingly retentive memory, and his lectures were thoroughly appreciated by the discerning student. Roscoe continued to direct the Chemical Department of Owens College until his election as Member of Parliament for the Southern Division of Manchester in the autumn of 1885, when he resigned the Professorship of Chemistry. On his retirement the Council recorded its strong sense of the eminent services he had rendered to the College through a period of thirty years, and its conviction that to his great attainments as a man of science, his skill and success as a teacher and organizer, his widespread reputation, and his high personal qualities, it was in great measure due both that the College enjoyed so high a rank as a place of education, and that its Chemistry Department in particular had long held a position second to that of no other academic institution in the United Kingdom. Similar testimony was borne by his colleagues when placing his portrait by Burgess in their Common Room, and by his pupils when offering another portrait by Herkomer to Lady Roscoe. The address accompanying this latter gift, and signed by upwards of two hundred old pupils, was as follows: _To Sir Henry Enfield Roscoe, M.P., D.C.L., LL.D., F.R.S., etc., Emeritus Professor of Chemistry in the Owens College, Manchester, February 16, 1889._