Extracts, are those medicinal preparations obtained by boiling vegetable substances in water, and evaporating the strained decoction in broad, shallow vessels, to a thick consistence. Thus the most active parts of the plants are separated from the useless insoluble earthy matter.

As extraction is a chemical process, generally performed by the apothecary, we shall only observe, that the following extracts are di-rected to be kept in the shops by the London College : viz. extract of broom-tops; of cascarilla ; of chamomile; of Peruvian bark with, and without, its resin; of colo-cynth compounded with aloes, scammony, etc. ; of gentian; of liquorice; of black hellebore ; of jalap : of log-wood ; of white pop. py ; of rue ; of savin ; of senna ; of wild cucumbers, etc.