The best type of strainer has yet to be evolved. Usually it consists in principle of a piece of fine brass mesh contained in some form of holder. Theoretically such a strainer should work well, but in actual practice nearly all strainers are a source of continual worry. Undiluted latex, as received at the factory, is of a rich consistency, containing very fine particles of dirt and often minute particles of prematurely coagulated rubber. The latter soon clog a fine mesh strainer, while the former may pass through. When the flow through the strainer becomes slow, the coolie in charge generally rubs the top surface of the sieve with a piece of coagulum, thus forcing material through the mesh. He then rubs the under-surface, with the result that undesirable matter falls into the strained latex. In theory it seems a simple matter to have a number of sieves ready so that a clean one may be substituted for a clogged one, which should be cleansed at once with water. In practice the factory coolie will probably only carry out instructions when the eye of the superintendent is alert. As a result of the rubbing and consequent strain, the brass mesh usually breaks away from its support and the fracture may not be detected for some time, during which irreparable damage may have been done to the resultant rubber. In view of the presence of the fine particles of dirt, to which allusion has been made, fine sieving of the latex appears to be essential, especially when sheet-rubber is to be prepared. The fine sieves are generally of the type known as "60 mesh," and they do not usually give thoroughly satisfactory results even when the gauze is supported and strengthened by means of cross-wires placed underneath. The general fault with these strainers is that a sufficiently wide "selvage" is not allowed in the clamped edges of the gauze, or that the edges of the support are so sharp and abrupt that the strands of the gauze are soon severed by the strain imposed in vigorous cleaning. Many estates use two strainers; the first a more robust one containing "30 mesh" gauze, and the second the fine "60 mesh." Even this device does not bring about the desired immunity from trouble. Relief could be obtained if the latex were always in a more freely fluid form. Estates employing anti-coagulants in the field benefit in this respect. Other estates, although finally using the finest of mesh, experience far less trouble than most estates by reason of a difference in method of working. This can be explained by an outline of the system adopted on a particular estate: (_a_) On arrival of the rich latex at the store, all visible coagulated lumps and other extraneous matter are removed by the tapper. (_b_) Each tapper's latex is diluted with a quantity of water.