London: Taylor and Francis, 1920. Hardcover. First Edition. vii, , 704 pp. 8vo. 15 Plates . Original brown library bindings with gold embossed titling to spine. Blind embossed library stamp on first free endpaper along with an ink WITHDRAWN stamp, blind embossed library stamp on title page; due date sheet tipped onto last page of volume, very clean within. Fine.
Aston's description of his early experiments demonstrating the "whole number rule" in which he determined that the precise atomic weight of a number of isotopes is based on whole number multiples of the mass of a hydrogen atom. Aston received the Nobel Prize for Chemistry in 1922 for his creation of the whole number rule.