SOCRATES, PinsoN OF. The name popularly given to three chambers hewn in the face of the hill of Philopappus at Athens. The chambers are of small dimensions, and one of them is connected with a vaulted rotunda, the circular opening of which was originally closed by slabs. The ar rangement in general is similar to that of the so called Treasury of Athens at :Nlycente.
SODA (It. soda, soda, saltwort, glasswort, con tracted from so/ida, fem. of so/i/o, from Lat. solidus, hard, solid : connected with OLat. soitas, Aos, bolos, Skt, sacra, whole, entire), or SODIUM CARBONATE, A white solid sub stance having a strong alkaline reaction and crys tallizing with ten molecules of water, 1011,0. In commerce it appears both with and without water. Crystallized, hydrated sodium carbonate, also called 'sal soda' is the common washing-soda: sodium bicarbonate, or 'acid' so dium carbonate, NafICO, is the common cooking soda, an important constituent of all baking pow ders. The dry carbonate. is used in enor mous quantities in the manufacture of glass and soap. Native sodium carbonate, or 'sodium ses quicarbonate; is found to some extent ill all dry regions, notably in Hun gary. Egypt, and the deserts of Africa, Asia. and North and South America. but in no other country does it occur in greater quantities than in the region lying east of the Sierra Nevada Mountains. The mineral is known as trona. Formerly most of the sodium carbonate of com merce was derived from the ashes of certain plants. chiefly barilla and kelp. but at the present time the quantity derived from all other sources is insignificant when compared with that manu factured from common salt.
Natural soda, which is the residue obtained by the evaporation of natural alkaline waters without the aid of artificial heat, occurs as white incrustations on the alkali plains; the most im portant deposits, however, are in the form of `sinks' or lakes without outlet, in which the leaching; and drainings of the alkali plains have been collected and concentrated. In the United States the waters of three lakes only. Albert Lake in Oregon and Mono and Owens lakes in Cali fornia, are estimated to contain more than 118, 000.000 tons of sodium carbonate and nearly 30, 000,000 tons of sodium bi-carbonate. Owing to the great distance from large Eastern markets and the consequent high freight charges, this im mense supply of raw material for the manufac ture of the various sodium salts has not entered into successful commercial competition with the brine deposits of the Eastern States. The pro duetion of soda ash (sodium carbonate), sal soda (hydrated), sodium carbonate, sodium bicarbo nate. and caustic soda (sodium hydrate), from 50 works in the United States during 190.2. ag gregated more than 500,000 tons. which involved ill the manufacture approximately 1,000,000 tons of salt. The quantities and values of these sodium compounds produced in the United States during 1000. according to the Twelfth Census, are given in the subjoined table: