674. Decoction
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.
675. Extracts
Extracts are made by evaporating the liquors obtained by infusion or decoction, but these can be bought much cheaper and better of chemists and druggists, and so can tinctures, confections, cerates and plasters, and syrups: but as every one is not always in the neighbourhood of druggists, we shall give recipes for those most generally useful, and the method of making them.
676. Precautions to be Observed in Giving Medicines.