From ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society.’
Calcium, Oxide of. See Lime.
Calcium, Phosphate of. Syn. Calcis phosphas (Ph. B.). Digest bone-ash, 4 oz., in hydrochloric acid, 6 fl. oz., diluted with a pint of water, until it is dissolved.
Filter the solution, if necessary; add water, 1 pint, and afterwards solution of ammonia (Ph. B.), 12 fl. oz., or a sufficient quantity, until the mixture acquires an alkaline reaction, and having collected the precipitate on a calico filter, wash it with boiling distilled water as long as the liquid which passes through occasions a precipitate when dropped into solution of nitrate of silver acidulated with nitric acid. Dry the washed product at a temperature not exceeding 212° F.
Calcium, Phos′phide of. Syn. Phosphu′ret of lime; Cal′cii phosphure′tum, C. phosphi′dum, L. Prep. By passing the vapour of phosphorus over lime (in small fragments) heated to redness in a porcelain tube. A brownish substance, supposed to be a mere mechanical mixture of phosphide and phosphate of calcium. Thrown into water, it suffers instant decomposition, and phosphuretted hydrogen gas escapes.
Calcium, Sulphides of. Calcium forms with sulphur at least three different compounds:—
1. Calcium, Protosul′phide of. CaS. Prep.—a. From sulphate of lime, exposed at a high temperature to a stream of hydrogen gas.—b. From dried gypsum, 25 parts; lampblack or finely powdered charcoal, 4 parts; calcined together at a strong heat in a covered crucible.
2. Calcium, Bisulphide of. CaS2. Prep. From sulphur and quick-lime, equal parts; water, q. s.; slake the lime, add the sulphur, and boil until a solution is obtained, which on cooling deposits crystals.
3. Calcium, Pentasulphide of. CaS5. Prep. As the last, but increasing the quantity of sulphur, and continuing the boiling for a longer period. Little is known about it.
4. Calcium, Sulphate of. See Gypsum.