THIS Table, together with the Fifth Report of the Committee on Atoms, was last published, in Paris, by the Union Internationale de Chimie just before the occupation of France. After that event Prof. E. Briner of Geneva very kindly offered to undertake the correspondence necessary to continue the work of the Committee. With his help I was able, as chairman, to draw up a Sixth Report which I submitted to him for publication early in 1941. Later in that year he informed me that unfortunately he had been unable to arrange for its publication, and requested me to draw up a modified report brought up to date for 1941-1942. This I did, and in February 1942 he wrote that I might soon expect the proofs of this. I have heard nothing from him since, and as I think further delay would be unfortunate, the report is appended. There has been very little published on the subject since it was drawn up and, so far as I have been able to ascertain, the other members of the Committee approve of all the alterations embodied in it.