MEMOIRS AND PROCEEDINGS OF THE MANCHESTER LITERARY & PHILOSOPHICAL SOCIETY, 1910-1911. CONTENTS. Memoirs: XXI. Dioptriemeters. By Prof. W. W. Haldane Gee and Arthur Adamson. With 8 Text-figs. (Issued separately, June Ist, 1911). - pp. I -16. XXII. The Development of the Atomic Theory: (7) The Rival Claims of William Higgins and John Dalton. By A. N. Meldrum (Issued separately, June rath, 191). pp. I-II. XXIII. On a Specimen of Osteocella septentrionalis (Gray). By Sydney J. Hickson, F.R.S, With 3 Text-figs. - (Issued separately, June I6th, 1011). pp. I-I5. XXIV. An Account of some Remarkable Steel Crystals, along with some Notes on the Crystalline Structure of Steel. By Ernest F. Lange, M. I. Mech. E., etc. 3 PIs. (Issued separately, August arst, 1911).pp. II5 Proceedings pp. xxiii-xxviii. Annual Report of the Council, with Obituary Notices of Prof. S. Cannizzaro, Rev. Robert Harley, F.R.S., Prof. J. H. van't Hoff, and Sir William Huggins, O. M., K.C.B., F.R.S. pp. xxix-xlii Treasurer