Old notices
These pages collect together notices posted on the IUCr web site in past years. They are retained for archival interest, but there is no guarantee (or likelihood) that many of the web links found in these notices will still be active.
The analytical theory of point systems
Thanks to the efforts of Alan Mackay, Emeritus Professor of Crystallography at Birkbeck College, London, and with the permission of the Executive Dean of Science at Birkbeck, the IUCr is pleased to make available Bernal's remarkable 1923 Emmanuel College Prize Essay in which, when still an undergraduate, he applied quaternions to the structure of crystal lattices. The Essay was published in 1981 as Occasional Paper No. 1, 1981, Department of Crystallography, Birkbeck College.
