A mixture of three parts of caustic soda to two of unslacked lime is a good detergent. The soda is boiled in the water, and then the lime added. The mixture should be applied hot, and be of the consistency of thick whitewash. In applying it great care should be exercised so as not to allow it to touch the hands. A brush of vegetable fibre should be used, as the composition will destroy hair. Caustic soda is used for cleaning off old paint or varnish; the mixture should be put on nine or ten hours before it is scraped off if a very clean job is desired. If it is a deck that has to be cleaned it is desirable to damp it with fresh water before an application of the mixture; hence it is a good plan to apply it on a dewy morning. Mahogany should not be cleaned with this compound, which turns it black. A mixture of two parts soda and one part soap, simmered together and applied hot, is sometimes used.