type, the growing use of the flexible plastics in the rubber factory, shortages of rubber, and military demands for low temperature Briefly, the collective compounder is largely responsible for the cost and quality of all rubber products, he controls the sale of raw materials to the rubber manufacturer, and he coordinates the technical progress of the industry. He has available a host of materials, a number of rather well-developed theories, and the support Of people in It is UP to the individual compounder to use these resources with skill, judgment, and tact in order to get the best results on his service. In addition to the classes of materials in general use, there are a number of materials, such as antiseptics, blowing agents for sponge rubber, odorants, peptizing agents, and retarders, which are used in special cases.In latex compounding all materials must be used as solutions or dispersions in water. This requires not only knowledge of colloidal Dhenomena but also a number of special types of materials. Some Miscellaneous Materials.phases Of the bf the more important types are antifoam agents, coagulants, dis-own particular problems. persing and wetting agents, gelling agents, and preservatives.