Chem. [f. (by Sir H. Davy) L. calx, calc(i)- lime, on the type of other names of metals in -UM, -IUM.]
1. A chemical element, one of the ‘metals of the alkaline earths,’ being the basis of lime; though one of the most widely diffused of elements, it is found in nature only in composition, and was first separated by Davy in 1808, as a light yellow metal, ductile and malleable, about as hard as gold, which rapidly oxidizes in air containing moisture, and forms ‘quick-lime.’ Symbol Ca.
1808. Sir H. Davy, in Phil. Trans., XCVIII. 346. I shall venture to denominate the metals from the alkaline earths barium, strontium, calcium, and magnium.
1815. W. Phillips, Outl. Min. & Geol. (ed. 3), 25. Lime has been proved by Sir H. Davy … to be a metallic oxide, consisting of 28 per cent. of oxygen and 72 of calcium.
1878. Huxley, Physiogr., 81. A solid carbonate of calcium, or, as it is more commonly termed, carbonate of lime.
1881. Lockyer, in Nature, No. 614. 321/2. Those short common lines of calcium which for years past we had watched coming out of the salts of calcium when decomposition was taking place.
2. attrib. = CALCIC; as in calcium compounds, salts, etc.; esp. calcium carbonate, CaCO3, carbonate of lime, or limestone, and arragonite; calcium chloride, Ca Cl2, chloride of lime, bleaching powder; calcium fluoride, Ca Fl2, fluor spar; calcium light, the lime-light; calcium oxide, Ca O, quick-lime; calcium phosphate Ca3 (PO4)2, phosphate of lime, the chief constituent of bone-ash; calcium silicate, Ca Si O3, found crystallized in tabular spar, etc.; calcium sulphate, Ca SO4, found crystallized as Gypsum.
1864. Daily Tel., 4 Oct., 5/2. A blinding ray from a calcium light apparatus shot right across for many hundred feet—a bridge of radiance.
1869. Roscoe, Elem. Chem., 154. When bones are burnt, a white solid mass is left behind; this is called Calcium Phosphate.
1872. Daily News, 7 Nov., 3/1. Calcium lights shone on smiling multitudes.
1873. Fownes, Chem., 364. Calcium Carbonate is always precipitated.
