Silicon

one of the earthy chemical elements. It is most common in nature in combination with oxygen, with which it forms common sand, or silica, as scientists call it. Next to oxygen silicon is the most common element in nature, and silica, that is to say, sand, is the most common sort of soil. Clay also contains silicon. Quartz is composed of silica. Pure silicon is known only in the laboratory. A slight admixture of silicon is said to improve brass. Added to copper wire, two pounds to the thousand, it seems to increase its conductivity. Silicon, in varying amounts up to fourteen pounds to the hundred, has been employed for a long time for iron workers to harden or soften, toughen, and strengthen wrought iron. The farmer is interested in silicon. It is the soil element that gives the corn stalk, stems of grasses, and straws of grain the flinty coating that enables such slender tubes to carry heavy loads and stand staunchly in the wind. Silicon is not, however, one of the elements absolutely essential to plant life. It is also found in animal bodies,--in the quill of feathers, as spicules in sponges, and as shields in some protozoa. The hair on one's head is partly silicon. A number of stones, favorites more or less with the jeweler, as opal, agate, amethyst, carnelian, onyx, flint, chalcedony, and rock crystal, are composed chiefly of silicon. The name silicon is derived from silex, flint, because flint is made of silicon chiefly.