"Take of Myrrh, in powder, two drachms; carbonate of potassa, a drachm; rose-water, eighteen fluid ounces; sulphate of iron, in powder, two scruples and a half; spirit of nutmeg, a fluid ounce; sugar, two drachms. Rub together the myrrh, the carbonate of potassa, and the spirit of nutmeg; and, while triturating, add first the rose-water with the sugar, then the sulphate of iron. Put the mixture immediately into a proper glass vessel, and stop it."

In this mixture the sulphate of iron is decomposed by the carbonate of potassa forming, by the change of constituents which takes place, sulphate of potassa and sesquioxide of iron mixed with a protocarbonate; the former of which is dissolved, while the latter is diffused through the mixture, and kept suspended by the myrrh, which forms a saponaceo-mucilaginous compound with the excess of alkali. The iron, which is in the state of a protocarbonate, rapidly attracts oxygen while the vessel is opened, and loses its carbonic acid, being wholly converted into the sesquioxide, which is insoluble, and, consequently, it is necessary to keep the mixture very well excluded from the air; or rather, it should not be kept prepared.

Medical properties and uses. - This mixture, which is nearly the same as the celebrated antihectic mixture of Dr. Griffith, is a useful tonic in all cases in which preparations of iron are indicated, particularly in hysteria and chlorosis, and in phthisis, when no active inflammatory diathesis subsists. The dose is from f j. to f ij. given two or three times in a day.