This process is not strictly of the same class as the others ; but as it makes use of the principle of the selective oiling of sulphide particles, and has other similarities to flotation processes, it should be described. In this process the crushed ore is fed to an agitator, Fig. 52. A ' magnetic paint ' is fed with the ore in quantity ranging from 40 to 6olb. per ton (4 or 5%) of ore. This magnetic paint is made by mixing one part of oil or thin tar of almost any kind with three or four parts of magnetic oxide of iron, natural or artificial. The oxide must be ground to an impalpable powder. In the mixer A the ore, with the paint and enough water to make a thick pulp, is agitated from five to twenty minutes to thoroughly mix the substances. The paint preferentially adheres to the sulphides because of its oily constituent. When this is accomplished the pulp is fed with some additional water to the upper end of the shaking conveyor B, along which it travels to the magnet C. Around the magnet C is an endless belt D, this belt being between the magnet and the conveyor. As the pulp passes along the conveyor it comes within the magnetic field, and the sulphide particles, partly due to their inherent magnetic permeability and partly to the magnetic permeability of the adhering magnetic paint, are drawn up against the endless belt D and carried outside the magnetic field, where they are washed into the launder E by a stream of water. It is claimed for this process that a great variety of products can be made by varying the material used for mixing with the magnetic oxide. We are already aware that the seriation of minerals, which exercise a preferential oiling, is of much wider range than the seriation of those which will preferentially float, and it is easily believed that among the thousands of oils and coal and wood tar derivatives there may be one which would preferentially adhere to almost any mineral chosen. This process is a new departure, and well worth research and development. At first glance the successful treatment of oxidized ores, not now treatable by any other process, would seem to lie in this direction. Whether the process could compete with gravity or flotation-concentration for sulphides at present lacks extended demonstration.