THE fifth lecture of a series on the influence of science and research upon current thought, established by the Carnegie Institution of Washington in honour of Mr. Elihu Root, who was, until his death last year, a member of the board of trustees of the Institution and its chairman during the last twenty-four years of his life, will be delivered by Sir Richard Gregory in the Institution's new1 auditorium on December 8. The subject will be “Cultural Contacts of Science” ; and the lecture will, therefore, be concerned mainly with associations of science with religion, literature and other aspects of intellectual development and social evolution, rather than with the services rendered to modern communities by utilitarian applications of scientific knowledge. As Mr. Root Was deeply interested in the relation between the advance of science and development of human values, it is appropriate that this should be the general theme of the series of lectures bearing his name. The lectures are published in book form after their delivery. The subject of the fourth lecture in the series was “The Concept of Uniformity: Growth and Reactions”, by Dr. F. H. Seares, assistant director of Mount Wilson Observatory.