text: He developed specialized techniques for the fractional precipitation and crystallization of the rare earths. The James Method, using bromates and double magnesium nitrates in fractional crystallization was widely used until the 1940s when Ion Exchange methods were developed. James himself became the major producer of extracted rare earth materials, supplying elements and compounds to researchers worldwide. His collection of rare earths was sold to the National Bureau of Standards after his death. It has since been returned to the University of New Hampshire, where it is the James Collection of Rare Earth Compounds, in the Department of Chemistry.