by chemists for dropping liquids, known by the name of a separating funnel, having a pear-shaped body, tapering to a fine sharp point, and a neck capable of being stopped with the finger or a cork, which may contain a liquid once or more; fill it with the liquid about one-quarter part, and the other three parts must be filled with the very best sulphuric ether.  If this be rightly managed, the two liquids will not mix.  Then place the tube in a horizontal position, and gently turn it round with the finger and thumb.  The ether will very soon be impregnated with the gold or platina, which may be known by its changing its colour; replace it in a perpendicular position, and let it rest for twenty-four hours; having first stopped up the upper orifice with a cork.  The liquid will then be divided into two parts—­the darkest colouring being underneath.  To separate them, take out the cork and let the dark liquid flow out:  when it has disappeared, stop the tube immediately with the cork, and what remains in the tube is fit for use, and may be called gilding liquid.  Let it be put into a bottle, and tightly corked.  The muriate of gold or platina, formed by digesting these metals in nitro-muriatic acid, must be entirely free from all excess of acid; because it will otherwise act too forcibly on the steel, and cause the coating of gold to peel off.  Pure gold must be employed; the ether must not be shaken with the muriate of gold, as is advised in chemical publications, for it will be sure, then, to contain acid; but if the two liquids be brought continually into contact by the motion described, the affinity between ether and gold is so strong as to overcome the obstacle of gravity, and it will hold the gold in solution.  The ethereal solution may also be concentrated by gentle evaporation.

537.  Varnish polish

Take 2 ozs. of tripoli, reduced to fine powder; put it into an earthen pot or basin, with water to cover it; then take a piece of fine flannel, four times doubled, lay it over a piece of cork or rubber, and proceed to polish your varnish, always wetting it with the tripoli and water.  You will know when the process is completed, by wiping a part of the work with a sponge and observing whether there is a fair and even gloss.  Take a bit of mutton-suet and fine flour, and clean off the work.  Or, the powdered tripoli may be mixed up with a little pure oil, and used upon a ball of serge, or of chamois leather, which is better.  The polishing may afterwards be completed with a bit of serge or cloth, without tripoli.  Putty powder, and even common whiting and water, are sometimes used for polishing; but they produce a very inferior effect to tripoli, except in the case of ivory, for which putty and water, used upon a rubber made of a hat, forms the best and quickest polish.  Putty and water may likewise be used, in the same manner as just mentioned for ivory, in finishing off the polish of pearl work, after it has first been polished very smooth with pumice-stone, finely powdered, and well washed to free it from impurities and dirt.