Polishing Mineral Specimens by the Use of an Optical Polishing Machine

The problem in this investigation was to determine if mineral specimens mounted in bakelite, or lucite, could be polished for microscopic examination by the use of an optical polishing machine, and if this method would cut down the length of time required to polish specimens by the methods now in use.

The Continuous Electrodeposition of Manganese

The object of this research was to produce a workable electrolytic cell for the continuous deposition of manganese from aqueous sulphate solutions and determine the critical factors in its oper­ation.