multiples of those referring to the larger one, as he wishes them to bear to each in the new mixture. Numerous other applications of this rule will occur to the ingenious reader.
Questions in ‘alligation,’ as the department of arithmetic above referred to is called, are very easily resolved by the ‘method of indeterminate analysis,’ even by persons but slightly conversant with rudimentary algebra; of which, indeed, they form a simple class of problems, often admitting of an almost indefinite number of solutions.
MO′HAIR. The hair of a goat indigenous in Asia Minor. It is dyed and manufactured by similar materials and in a similar manner to wool.
MOIL. See Cider.
MOIRÉE METALLIQUE. [Fr.] A beautiful crystalline appearance produced on the surface of tin plate by acids. The tin plate is submitted for a few seconds, whilst gently heated, to the action of dilute aqua regia, by which it acquires a variegated primrose appearance. It is afterwards washed in hot water, dried, and lacquered. The degree of heat and dilution of the acid modifies the beauty and character of the surface. The effect is also varied by employing dilute sulphuric acid, either alone or mixed with a portion of nitric or hydrochloric acid; or by using a solution of citric acid or caustic potassa. According to Herberger, the best metal for the purpose is plate iron, which has been coated by dipping it into a tin bath composed of pure tin, 200 parts; copper, 3 parts; arsenic, 1 part. The varnish should consist of copal in highly rectified spirit. Moirée metallique is in much less demand now than formerly.
MO′LASSES. See Treacle.
MOLES. The small, soft excrescences and discolorations of the skin which are popularly known under this name may, when slight, be removed by touching them every day with a little concentrated acetic acid, by means of a hair pencil, observing due care to prevent the application from spreading to the surrounding parts. This does not discolour the skin. The application of lunar caustic is also very effective, but it turns the spot temporarily black. In the pure mole there is always a considerable production of hair. When other means fail, they may be easily and safely removed by surgical means. The operation is trifling; and when judiciously performed no trace of such a proceeding is left behind.
MOLUC′CA BALM. See Liqueur.
MOLYBDATE OF AMMONIUM. (NH4)2 MoO4. Syn. Molybdenic acid, Peroxide of molybdenum; Acidum molybdicum, L. Prep. Native sulphide of molybdenum, after being well roasted, is reduced to fine powder, digested with ammonia, and the mixture filtered, and the filtrate evaporated to dryness; the residue, molybdate of ammonium, is then
dissolved in water, purified by crystallisation; and, lastly, decomposed by heat.