Page:The British pharmacopœia.djvu/518

484 SOLUTION OF PERCHLORIDE OF PLATINUM.

Take of

Mix a fluid ounce of the nitric acid with four fluid ounces of the hydrochloric acid and two fluid ounces of the water; pour the mixture into a small flask containing the platinum, and digest with a little heat, adding more of the acids mixed in the same proportion, should this be necessary, until the metal is dissolved. Transfer the solution to a porcelain dish, add to it a fluid drachm of hydrochloric acid, and evaporate on a water-bath, until acid vapours cease to be given off. Let the residue be dissolved in the remaining five ounces of distilled water. Filter, and preserve it in a stoppered bottle.

SOLUTION OF PHOSPHATE OF SODIUM.

Take of

Dissolve and filter.

SOLUTION OF POTASSIO-MEROURIC IODIDE.

Synonym.—Nessler's Reagent.

Take of

Dissolve the iodide of potassium and 100 grains of the perchloride of mercury in fifteen fluid ounces of boiling distilled water. To this fluid add more aqueous solution of the perchloride of mercury until the precipitate produced no longer