"An investigation was undertaken to study the feasibility of using induction heating, with an internal susceptor, in the zone melting of organic compounds. Zone melting is a generic term embracing a variety of techniques that involve passing a molten zone through a solid sample; the components of the sample are thus distributed according to their differences in solubility in the solid and molten phases. The zone-melting principle is used in zone refining, a purification technique; in zone leveling, a method for distributing trace components to produce special-property alloys; in zone chromatography, a method suggested (6) for separating complex mixtures; and in many other applications. (7) The ultimate goal of the investigation was the development of zone chromatography for the separation of components of high-boiling petroleum fractions and residues. Zone refining was first applied to metals (4) and yielded purides previously considered impossible. The process involves the repeated passage of a molten zone in one direction through a solid in get of sample. The zone refining technique has been used in this laboratory to purify standard samples of organic nitrogen compounds for American Petroleum Institute Research Project 52. (1) In the course of this zone refining work, researchers became aware of certain characteristics of the externally heated zone-melting system that handicap its use in zone chromatography."