Decoction, or boiling, is employed to extract the mucilaginous or gummy parts of substances, their bitter, astringent, or other qualities, and is nothing more than boiling the ingredients in a saucepan with the lid slightly raised. Be sure never to use an iron saucepan for astringent decoctions, such as oak-bark, galls, &c., as they will turn the saucepan black, and spoil the decoction. The enamelled saucepans are very useful for decoctions, but an excellent plan is to put the ingredients into a jar and boil the jar, thus preparing it by a water bath, as it is technically termed; or by using a common pipkin, which answers still better. No decoction should be allowed to boil for more than ten minutes.