1. For the preparation of large supplies of standard solutions, supposing a small quantity of the correct solution to be at hand.

2. For the determination of the specific gravity of waters in general, and sea-water in particular, as of dilute solutions generally.

3. For the execution of Hammer's process for the determination of tannin in infusions of oak bark, etc. (see Fresenius's "Quantitative Analysis," p. 673, of edition vi.).

4. For the examination of butter fat by Mr. Bell's method.-Chem. News, July 29th, 1881, p. 51.

SOLUTION, PERCOLATION, ETC.

Apparatus for Determining Solubilities at High Temperatures.Victor Meyer has devised the apparatus illustrated by Fig. 4, by means

Meyer's Apparatus for Determining Solubilities at High Temperatures.

of which the exact solubility of substances at high temperatures may be determined, the whole operation being performed within an atmos

phere raised to the proper temperature. A suitable quantity of the solvent, together with an excess of the substance, having been previously heated to the desired temperature, the mixture of solution and undissolved substance is transferred to the bulb-tube a, which is previously connected with the other parts of the apparatus, as shown in the cut. The lower end of the tube is closed by a rubber stopper (not shown in the cut), which is perforated by a hole closed by the end of a glass rod b. The end of the tube passes through a rubber stopper in the neck of a pear-shaped funnel f, within which is placed a dry filter. The funnel is connected with the small flask n. p is a thick silver or platinum wire, spirally twisted below, by means of which the solvent and substance may be agitated. From the small flask ʼn projects a chloride of calcium tube h, filled with fragments of this salt, which tube may be omitted in all cases where a somewhat considerable amount of solution is collected in the flask, as the amount of water lost by evaporation is comparatively small. Before the experiment, the flask n is weighed together with the chloride of calcium tube. The connections are then made, as shown in the cut, and the whole of the apparatus connected with the large rubber stopper m is now inserted into the receptacle 1. Water, or some other liquid furnishing the proper temperature when boiling, is heated in the flask, and the vapor of the liquid allowed to pass through the apparatus for about fifteen minutes, any condensed liquid being caught by the beaker placed below. The solvent and substance having repeatedly been agitated with the wire p, a suitable quantity of the solution is finally allowed, by slightly disengaging the glass rod b, to flow into the filter f, and thence into the flask n. When sufficient solution has passed into the latter the current of steam is interrupted, the apparatus taken apart, and the flask n with the chloride of calcium tube, after being thoroughly dried outside, weighed. The contents of the flask are then rinsed into a capsule, and the solid contents determined by evapora tion to dryness.-New Rem., March, 1882, p. 67.

Percolation-Objections to the Process for the French Pharmacopoia. From a report in the "Répertoire de Pharm.," it appears that the next revision of the Codex will give the preference to maceration over percolation in preparing tinctures. The reasons given are as follows:

1. Maceration gives excellent results every time a substance is to be exhausted with the smallest possible quantity of menstruum.

2. It affords products identical, and often superior, to those obtained by percolation.

3. It requires no delicate manipulation, often difficult for unskilful or inexperienced hands.

4. It necessitates no pulverization, and, therefore, dispenses with

the previous desiccation by which some active and volatile principles are often dissipated.

At the same time, percolation will not be absolutely discarded. The future Codex will give a process for the use of the pharmacist, when, for some reasons, he may think percolation preferable-Drug. Circ., January, 1882, p. 1.

A New Percolator.-Mr. Nathan Rosenwasser describes a new percolator, which is illustrated by Figs. 5 and 6. It is simply the ordi

nary percolator reversed, attaching a long tube (rubber usually answers) to the nozzle, and connecting it to the menstruum reservoir C

(Fig. 5), for which a funnel or similar apparatus will answer. Fig. 5 represents the percolator in position, ready for the liquid to flow, while Fig. 6 represents the percolator inverted, with the open end, E, apart, and ready for packing the drug. The porous diaphragm (B, Fig. 6, G, Fig. 5) is first placed in position; the drug is, after previous moistening, packed tightly into the percolator, occupying the dotted space C, Fig. 6, and H, Fig. 5. A porous diaphragm (D, Fig. 6, J, Fig. 5) is placed on the drug and fastened to the body of the percolator by any simple contrivance. The bottom-plate (H, Fig. 6, L, Fig. 5) is easily secured to the body of the cylinder, and the bottom or outlettube is easily closed with cork or rubber tube and pinchcock. The percolator, having been packed very tightly on the bottom, and less so proceeding upward, and the diaphragm holding the drug in place, having a piece of muslin or filtering medium placed between it and the drug, is now reversed; the menstruum reservoir (C, Fig. 5), is attached by means of the tube (E, Fig. 5), and suspended by the handle of the menstruum reservoir. The percolator is ready, the menstruum is poured into the reservoir, the opening to which is closed with a notched cork, and percolation begins.

The advantages of this form of percolator and the process involved in its use are, in the author's experience, manifold. The drug is held in place so that it cannot expand in any direction; this insures the greatest possible compactness, while, by increasing the height of the column of menstruum, lateral pressure is completely overcome and percolation proceeds at the will of the operator, and not, as heretofore, at the will of the drug. A minimum quantity of liquid only is consumed in the process, and it is quite possible to exhaust drugs completely by 1 pint of menstruum for 16 troy ounces, while the portion of menstruum retained by the drug, which is reduced to a minimum, is almost completely expelled by water. Such drugs as rhubarb, squill, colomba, dandelion, etc., have been converted into fluid extract by percolation with proof spirit (using 17 fluid ounces per 16 troy ounces of drug) followed by water, with excellent results.-Am. Jour. Phar., November, 1881, pp. 567–572.

New Displacement Apparatus.-Mr. Robert F. Fairthorne describes. a new displacement apparatus, which is illustrated by the accompanying cut (Fig. 7). The shape of the percolator differs somewhat from the usual form, being to some extent egg-shaped, whereby free percolation is insured. The cover (B), which is hemispherical in shape, is fastened upon the body (A) by means of clamps, with india-rubber rings between to render the joint air-tight. The drug to be operated on, having been sufficiently moistened with the menstruum and packed, is next exhausted of as much air as possible by a vacuum being produced through the upper part of the vessel by means of an air-pump

(G), which is connected with it by means of the tube (F). The stopcock (H) is next closed and (M) opened, connecting with the tube (E), the end of which dips into the liquid to be employed as menstruum, and thereby a sufficient quantity of it is allowed to be drawn into the displacer to cover the drug. The stopcock (M) is then closed and the materials allowed to macerate for several days. To start the percolation the receiver (C) is exhausted of air and the tap (I) having been

opened the saturated fluid will begin to drop, and continue to do so so long as the force of the vacuum in the receiver is equal or greater than that in the upper vessel. When it begins to stop, air is admitted above the drug, which is drawn through the material, carrying with it much of the remaining liquid. To finish the operation air is forced into the percolator by means of the pump.