(4) _It is important to see that the sheets are now well washed or scrubbed under running cold water, or in frequent changes of water._ The reason for this procedure is plain. If the sheets are merely hung again to drip after removing from the hot water, some moisture is bound to remain on the surface of the sheet. As this surface moisture contains some protein matter in solution, it is evident that, as the water evaporates, the solid protein is again deposited on the surface of the rubber. This would explain why some estates were unsuccessful with the hot-water treatment. It is not essential that the running water should be cold; it may be conveniently lukewarm if drawn from the cooling tanks of the engines. But it is essential for the best results that there should be running water, so that the substance in solution is carried away. If the sheets are merely washed in a large vessel, which has been filled with clean water, it must be obvious that, by the time some scores of sheets have been washed, the protein matter in solution on the surface of the sheets has been transferred to the washing water, so that the later sheets of the batch are liable to show the defect again on drying. B. The second method is much more simple, and entails no extra labour such as is demanded by the first method. A successful issue, however, is rather more uncertain, and the method appears to give the best results with sheet-rubber prepared on young estates or from more dilute latex. In this method, the sheets after rolling are allowed to drip for a very short interval, so that the surface water is mainly removed. The sheets are then placed in the smoke-house, and smoking is commenced at once. In some cases where the defect had appeared continuously for a long period, it was found to vanish entirely as soon as the method was adopted; but when tried on some of the older estates, the results were very doubtful, and a return was made to the hot-water treatment. The explanation of the action which takes place is rather obscure, but two theories may be advanced. (_a_) It may be assumed that the interval given for dripping is too brief to allow for the exudation of the internal moisture containing dissolved protein matter.