This is made by dissolving freshly prepared hydrated sesquioxide of iron in citric acid, saturating with carbonate of magnesia, evaporating to the consistence of syrup, and drying in thin layers. It is in translucent scales, of a greenish-yellow colour, and an acidulous, slightly chalybeate taste, very soluble in water, but insoluble in alcohol. It has the general properties of the ferruginous preparations, and may be given in the dose of five grains or more, in pill or solution.