The new bleached fat, containing the Fuller's earth is pumped directly to a previously heated filter press and the issuing clear oil run directly to the soap kettle. One of the difficulties experienced in the process is the heating of the press to a temperature sufficient to prevent solidification of the fat without raising the press to too great a temperature. To overcome this the first plate is heated by wet steam. Air delivered from a blower and heated by passage through a series of coils raised to a high temperature by external application of heat (super-heated steam) is then substituted for the steam. The moisture produced by the condensation of the steam is vaporized by the hot air and carried on gradually to each succeeding plate where it again condenses and vaporizes. In this way the small quantity of water is carried through the entire press, raising its temperature to 80deg.-100deg. C. This temperature is subsequently maintained by the passage of hot air. By this method of heating the poor conductivity of hot air is overcome through the intermediary action of a liquid vapor and the latent heat of steam is utilized to obtain the initial rise in temperature. To heat a small press economically where conditions are such that a large output is not required the entire press may be encased in a small wooden house which can be heated by steam coils. The cake in the press is heated for some time after the filtration is complete to assist drainage. After such treatment the cake should contain approximately 15 per cent. fat and 25 per cent. water. The cake is now removed from the press and transferred to a small tank where it is treated with sufficient caustic soda to convert the fat content into soap. Saturated brine is then added to salt out the soap, the Fuller's earth is allowed to settle to the bottom of the tank and the soap which solidifies after a short time is skimmed off to be used in a cheap soap where color is not important. The liquor underneath may also be run off without disturbing the sediment to be used in graining a similar cheap soap. The waste Fuller's earth contains about 0.1 to 0.3 per cent. of fat. METHOD FOR FURTHER IMPROVEMENT OF COLOR. A further improvement of the color of the tallow may be obtained by freeing it from a portion of its free fatty acids, either with or without previous Fuller's earth bleaching. To carry out this process the melted fat is allowed to settle and as much water as possible taken off. The temperature is then raised to 160deg. F. with dry steam and enough saturated solution of soda ash added to remove 0.5 per cent. of the free fatty acids, while agitating the mass thoroughly mechanically or by air. The agitation is continued ten minutes, the whole allowed to settle for two hours and the foots drawn off. The soap thus formed entangles a large proportion of the impurities of the fat. VEGETABLE OILS.