Extractum Coto Fluidum.—Fluid Extract of Coto.
Related entry: Coto.—Coto Bark
Preparation.—Take of coto bark, in very fine powder, 16 troy ounces; alcohol, a sufficient quantity. Moisten the coto with 6 fluid ounces of alcohol. Cork tightly in a wide-mouth bottle, and permit the mixture to stand an hour in a warm situation. Then introduce it into a cylindrical percolator, 3 inches in diameter, previously prepared for percolation, according to directions given on page 756, and press very firmly. Cover the surface of the powder with a circular piece of filtering paper held in position with a few fragments of glass or marble, and add alcohol until the percolate appears at the exit. Then cork the exit tightly; cover the percolator, and place it in a warm situation. After 24 hours, loosen the cork, and permit the percolate to pass as fast as it will drop, without running in a stream, until 4 fluid ounces are obtained. Again close the exit, macerate 24 hours, and, in a manner like unto the preceding, draw 4 fluid ounces of percolate. Repeat the maceration, and, in like manner, draw a third portion of 4 fluid ounces. Reserve, and mix the three percolates; then continue the percolation until 8 fluid ounces are obtained. Evaporate this latter portion until reduced to the measure of 2 fluid ounces, and mix with the reserved 12 fluid ounces. The surface of the powder must be constantly covered with alcohol from the commencement, and until the end of the process of percolation.
Description, Medical Uses, and Dosage.—Fluid extract of coto is of a reddish color, possesses an aromatic odor and a hot taste, followed by a numbness of the tongue, and, as thus prepared, it represents very nearly the quality of drug employed, troy ounce to each fluid ounce of the finished extract. A mixture of alcohol and water will produce a much darker fluid extract; but alcohol is the best solvent for the characteristic medicinal principles of the drug, and the coloring matter observed in the aqueous extract is undesirable. The addition of water to the menstruum also renders the finished extract more prone to precipitation.