Extractum Asclepiadis Fluidum. Extractum Aspidospermatis Fluidum. Extractum Cimicifugæ. Extractum Convallaria Fluidum. Extractum Eriodictyi Fluidum. Extractum Jalapæ. Extractum Lappæ Fluidum. Extractum Menispermi Fluidum. Extractum Phytolacca Radicis Fluidum. Extractum Rhamni Purshianæ Fluidum. Extractum Scoparii Fluidum. Extractum Uva Ursi. Extractum Viburni Opuli Fluidum. Ferri et Quininæ Citras Solubilis. Resorcinum. Rhamnus Purshiana. Salol. Sparteinæ Sulphas. PERCOLATION. Percolation is the process whereby a powdered substance contained in a suitable vessel (called a percolator) is deprived of its soluble constituents by the descent of a solvent through it. The solvent used is called the menstruum, and the liquid coming from the percolator after having passed through the drug is termed the percolate. The percolator most suitable for the quantities contemplated by the U. S. Pharmacopoeia should be nearly cylindrical, or slightly conical; with a funnelshaped termination at the smaller end. The neck of this funnel-end should be rather short, and should gradually and regularly become narrower toward the orifice, so that a perforated cork, bearing a short glass tube, may be tightly wedged into it from within until the end of the cork is flush with the outer edge of the orifice. The glass tube, which must not project above the inner surface of the cork, should extend from 3 to 4 Cm. beyond the outer surface of the cork, and should be provided with a closely fitting rubber tube, at least one-fourth longer than the percolator itself, and ending in another short glass tube, whereby the rubber tube may be so suspended that its orifice shall be above the surface of the menstruum in the percolator, a rubber band holding it in position. The shape of a percolator should be adapted to |