Calcium

(kal'se-um.) [L. calx, lime.] (Chem.) The metallic base of lime, first isolated by Davy in 1808. It is a light yellow metal, about as hard as gold, very ductile and malleable. It rapidly decomposes water, and burns with a very bright flame. Sp. gr. 1-5778; at. weight 20; symbol Ca. Calculating-Machine, a piece of mechanism for a isting the human intellect in the performance of arithmetical operations. Among the various machines that have been invented for this object, the one devised, in 1855, by Scheutz, a printer at Stockholm, and in use at the Dudley Observatory at Albany, is the only one ever completed. [s. 130]