FIBR

155

Adulterated with an impure preparation, but the fraud may be knownby the dulness of the colour.

Incompatible with tannin, and vegetables containing it, with potass,soda, magnesia, lime, and their carbonates.

Medicinally it is, like the other preparations of iron, a diffusible tonicand aperient, in doses of gr. iij to 3j in form of pill for re-laxed habits, but being uncertain in strength is not often pre-scribed.

Enters into Tinct. Ferri Ammoniati. L.Ferrum Tartarizatum. L. Tartarized Iron. Tarlras potasses elferri. E. P. Tartarum ferri. D. Tinctura inarlis tarlarisaia. O.Take Ibj of iron, ftij of supertartrate of potass in powder, Ov or q. s.of distilled water. Triturate the iron and the supertartrate ofpotass together, expose them to the air with a pint of water for 20days in a shallow glass vessel, stirring them daily, and addingdistilled water from time to time to keep them always moist; boil infour parts of the water for a quarter of an hour, filter and evaporatethe filtered liquor in a water-bath to dryness, reduce the residuumto powder, and keep it in a well-stopped phial. It is a greenishbrown powder, with no smell, and little taste.

Decomposition. The air and the water supply their oxygen to theiron, while the oxide thus formed combines with the superabundantacid of the supertartrate of potass, and the mass consists of metalliciron, oxide of iron, with tartrate of iron and potass: or when verycarefully prepared it is a double salt consisting of pertartrate of iron,and of potass. The moist mass is the best preparation; for evaporat-ing to dryness partially decomposes it.

Incompatible with strong acids, and the fixed alkalies and their car-bonates (but not with ammonia), with the sulphuret of potass, andinfusion of galls, oak bark, and all astringent vegetables, whichform a tanno-gallate of iron, of similar properties, however, to thegenuine preparation.

Impaired by tartrate of lime, which is frequently mixed with the su-pertartrate of potass used in the preparation.

Medicinally it is seldom prescribed, but may be added to other chaly-beates. The dose is gr. x to 5ss in solution or in bolus with bittersand aromatics.Ferrum Vitriolatum. O. See Ferri Sulphas. L.Ferruretted Chyazic Acid. A name proposed by M. Porrett for

Ferro-cyanic Acid.Ferula. See Assaecetida.Fever Balls, in Farriery. See Balls.Fibrin. A peculiar substance found both in animals and vegetables.