Crystallized sulphate of iron, 256 grains.

Bicarbonate of sodium, 200 grains.

Hydrochloric acid, simple elixir, distilled water, of each a sufficient quantity.

Dissolve the sulphate of iron and bicarbonate of sodium separately, each in sixteen fluidounces of distilled water, and mix the solutions; pour the mixture into a bottle, which must be filled to the stopper, using more distilled water if necessary, and permit it to rest twenty-four hours; decant the clear solution and refill the bottle with freshly distilled water, shaking well, and permit it to stand as before. After twenty-four hours decant the solution; pour the residue upon a fine muslin strainer and squeeze the liquid from it. Dissolve the precipitate by trituration in a mortar with hydrochloric acid in sufficient amount, and then add enough simple elixir to make sixteen fluidounces, and filter it.

Each fluidrachm (teaspoonful) of the finished elixir contains of chloride of protoxide of iron (ferrous chloride) an amount which is equivalent to two grains of crystallized sulphate of iron.

This elixir may also be made by the action of hydrochloric acid on metallic iron, using the same amount of acid, two hundred grains of iron, two fluidounces of water, and a sufficient quantity of simple elixir. Digest the iron, water, and acid together until the action ceases; filter, and mix the filtrate with simple elixir in amount sufficient to form sixteen fluidounces. This preparation is unstable.