The important facts developed by the investigation are: Group III can be subdivided into two divisions without much injury to the delicacy of the individual tests. [See document for Scheme of Analysis For Group III] [See document for Diagramatic Scheme of Group III] The successful division of this group has eliminated the possibility of certain metals oxidizing during their initial precipitation and washing.* That the present of chromium precipitates an additional eleven per cent of zinc, but does not appreciably effect manganese. That different concentrations of ammonium hydroxide and ammonium chloride will precipitate varying amounts of zinc and manganese. The writer feels quite sure that his method requires less time and is less expensive than other methods.* / M.S.