"Beat the fresh substance, and press it strongly through a canvass bag, in order to obtain the juice; which being put into a wide, shallow vessel, and heated by means of boiling water saturated with sea-salt, is to be reduced to the consistence of honey. The mass when cold is to be put into glazed earthen vessels, and moistened with strong alcohol."

The juices of fresh vegetables obtained by expression contain, besides the sap of which they chiefly consist, mucilage, fecula, extractive matter, and the other proper juices of the plant. When newly expressed, these matters are mixed together, and form a viscid, heterogeneous fluid, which gradually separates by rest into two parts; the one formed of a deposit of all the insoluble components of the juice generally involved in mucilaginous matter; the other a clear liquor, consisting of water, holding some mucilage in solution, with, the acids and salts, if any, and other soluble principles of the juice. As the clear liquor is that which is wished to be obtained for medical use, it is separated by first decanting it from the deposit, then filtering it repeatedly through a linen cloth, and adding about one-fortieth part of its weight of alcohol; after which it is allowed to remain at rest for some time, and again filtered previous to being put into the bottles in which it is intended to be preserved.

The bottles should be kept in a cool cellar, and sunk up to the neck in sand.

Various other methods, also, are employed for depurating vegetable juices; but as these preparations are now almost obsolete, we do not think it necessary to detail them. By whatever means they are prepared, vegetable juices undergo chemical changes, and spontaneous decompositions from keeping, which must necessarily affect their virtues as medicines, They are, therefore, properly rejected from all the Pharmacopoeias.

The articles given in the Edinburgh Pharmacopoeia, under the title Succi spissati, being associated by the London College with the extracts, and the difference between these preparations being scarcely sufficient to constitute a generic distinction, we have thought it proper not to alter the London arrangement in this respect, and have therefore placed the whole under the title Extracts.