Prop., Uses, &c. This salt crystallises in colourless, striated, hexagonal prisms, terminated by very acute points. It is very soluble in alcohol and water, the latter even at 32° dissolving more than its own weight, and at 60° three or four times its weight of this salt. When heated, the crystals undergo watery fusion. When dissolved in water, they produce great cold; and hence are frequently employed as an ingredient in FREEZING MIXTURES. These crystals contain nearly half their weight of water. They are very deliquescent, passing readily into the liquid state, and forming what used to be called oleum calcis, or oil of lime. The anhydrous chloride
is hard and friable; slightly translucent; totally and readily soluble in water, and, like the crystallised salt, very deliquescent. In the laboratory chloride of calcium, either fused or merely dried, is continually used for drying gases and for absorbing the water from ethereal and oily liquids in organic analysis. The unfused is now generally preferred for this purpose, as it is more porous than the fused. The salt is also used in the rectification of alcohol, and to form a bath for heating stoneware stills and other apparatus liable to be cracked on the sand bath. As a chemical reagent it is employed chiefly in detecting certain organic acids. As a medicine it has been given in some scrofulous and glandular diseases. Dose, 10 to 20 gr. See Solutions.
Calcium, Flu′oride of. CaF2. Syn. Hydroflu′orate of lime. This occurs native as the mineral called fluor-spar. It is found in beautiful crystals in the lead mines of Alston Moor and Derbyshire, and in the concretionary crystalline masses known as Blue John or Derbyshire spar at Castleton. It may be prepared by the action of hydrofluoric acid upon lime, as directed under Barium, Fluoride of.
Calcium Hypophosphite. CaP2H4O4. Mix milk of lime (1 in 5) in porcelain capsule placed in a sand bath, with half its weight of phosphorus in small pieces, and heat it to ebullition, operating in the open air or under a chimney with a good draught. Spontaneously inflammable phosphuretted hydrogen is given off, the vapour of which should be avoided. Add from time to time a little warm water, to replace that which has evaporated. Discontinue the heat when the phosphorus has disappeared—that is, when inflammable bubbles cease to be produced. If the phosphorus remain in excess, add more milk of lime, and continue the heat until the complete disappearance of the metalloid. Allow the liquor to cool and then filter; then saturate it with a current of carbonic acid gas to eliminate any excess of lime remaining uncombined. Filter again, and concentrate the liquor in a water bath to dryness, keeping the temperature below 100° C., to avoid detonations. Preserve the salt from the air in well-closed bottles.
From ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society.’
Calcium, I′odide of. CaI2. Syn. Hydri′odate of lime; Cal′cii iodi′dum, Calcis hydrio′das, L. Prep. 1. (Magendie.) From a solution of protiodide of iron and hydrate of calcium, as directed under iodide of barium.
2. Dissolve lime or carbonate of lime in hydriodic acid.
Prop., Uses, &c. It is a deliquescent salt, easily soluble in water, and has a bitterish taste. It has been used in scrofulous affections, internally, in doses ranging from 1⁄8 to 2 gr., thrice daily, and externally in ointments containing 2 dr. or less to the oz.
Calcium, Lactophosphate. This product ought not to be employed except in the state of solution in water or in syrup. In the pasty or solid state its solubility varies, and it is always an indefinite compound.
Solution. Bibasic phosphate of lime, 17 grams; concentrated lactic acid, as little as possible; distilled water, 964 grams. Suspend the phosphate carefully in the distilled water, add the lactic acid, allow solution to go on for some minutes, and filter.