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out well. The extracted salt leys, by being run through a lime cave, might have been converted into a good caustic ley, and used over again with advantage.

Soap-makers will do well to consider this case with attention. By so doing, disagreeable circumstances of a similar nature may be avoided; and, consequently, much time, expences, and an infinite quantity of trouble, saved. No soap-ley at any time ought to be used, but such as, by experiment, is proved to be a caustic ley, entirely freed from its fixed air. And it is with much satisfaction we present the reader, in the following Number, with the experiments of an able and justly celebrated chemist, made expressly with the view of ascertaining this important and fundamental requisite in soap-making, and therefore can with confidence be recommended to the practice of the manufacturer.