SODOM SOUL it combines with seven molecules of water of crystallization, and does not effloresce. On adding free phosphoric acid to a solution of rhombic phosphate, biphosphate of soda, NaH a + PO 4 + H 2 0, is formed, which crystal- lizes in right rhombic prisms having a strong- ly acid reaction. There are several metaphos- phates of sodium, and also double salts of the same constitution in which another metal is one of the basyles. There are several pyro- phosphates, embracing also both single and double salts, for a description of which the reader is referred to the larger works on chem- istry. The silicates of sodium are glasses of various degrees of fusibility, and also of solu- bility in water. (See CONCRETE, GLASS, and GLASS, SOLUBLE.) There are several organic salts of sodium, the principal of which are acetates, citrates, oxalates, tartrates, and vale- rianates ; but they do not possess sufficient gen- eral interest to require notice here. General Characteristics of Sodium Salts. There v are no good direct tests of sodium salts, because they are nearly ail soluble, so that the presence of sodium is often inferred when the absence of every other metal is proved, and yet a saline substance remains which yields yellow, striated, prismatic crystals on addition of chloride of platinum and evaporating the solution, a double salt of sodium and platinum being formed. The detection of this double salt is more cer- tain by microscopic examination with polar- ized light, which tinges the crystals with va- rious characteristic colors. Before the blow- pipe the salts of sodium impart an intense yellow to the outer flame. Spectroscopic ex- amination reveals pure yellow light having the same position in the solar spectrum as the double line D. The chief distinguishing char- acteristics between sodium and potassium salts are, that the latter impart a violet color to flames, and are generally more insoluble, as shown in the slight solubility of sulphate of potassium and the great solubility of Glauber's salt. Many sodium salts moreover effloresce on exposure to the air, while potassium salts generally deliquesce, a fact markedly shown in the carbonates. SODOM, in Biblical history, one of the five cities of the plain or valley of Siddim, de- stroyed on account of the wickedness of the inhabitants. (See DEAD SEA.) SOEST, a town of Prussia, in the province of Westphalia, 13 m. . by E. of Arnsberg; pop. in 1871, 12,404. It has a Catholic cathedral, and among the Protestant churches the re- stored Weisenkirche is remarkable for its pure Gothic architecture. There are many brew- eries and several manufactories. The princi- pal trade is in grain. The plain surrounding the town contains 10 villages, and is very fer- tile. Soest was once a Hanseatic town of great importance, but has never recovered from the effects of the thirty years' war. SOFALA. I. A country on the E. coast of Africa, within the territory of Mozambique, of which it forms the southern half. It ex- tends from about lat. 18 to 24 S., and from the seaboard to the Motapa mountains, hav- ing an extreme length of about 400 m. and a breadth of nearly 200 m. Along the coast the land is low and swampy, but it rises toward the interior till it terminates in the Motapa range. The country is watered by several considerable rivers, of which the most impor- tant are the Sofala, the Sabia, and the Inham- ban or Inhambane. The Portuguese establish- ed colonial settlements in Sofala early in the 16th century, and the country is still nominal- ly a dependency of Portugal, although Euro- pean rule is really limited to the few garri- soned stations near the coast. The chief towns are Sofala and Inhamban ; the latter port is 8 m. from the mouth of the river of the same name, in lat. 23 57' S., Ion. 36 6' E., and has a good harbor. The exports are mainly am- ber, beeswax, and ivory. The natives are ne- groes, and the slave trade is carried on, but to no considerable extent. Sofala was formerly celebrated for its export of gold dust, and some geographers have supposed it to be the Ophir of the ancients. The coast region is very un- healthful. II. A town in the above country, formerly the capital of a native kingdom, at the mouth of the river Sofala, in lat. 20 3' S., Ion. 84 39' E. It has a fort and a church, and consists of a feAV mud and straw huts, though once a place of considerable trade. A bar at the mouth of the river interferes with the approach of large vessels. SOGDIANA, an ancient country of Asia, S. E. of the sea of Aral (Oxianus Lacus). It was separated from Bactria on the southwest by the Oxus, and from Scythia on the north by the Jaxartes, thus embracing a part of modern Bokhara. The Persians conquered it in the time of Cyrus. Alexander invaded it in 329 B. 0., and established some colonies. After his death it belonged to Syria, and subsequently fell to the Turkomans. SOHAR, a seaport town of Oman, Arabia, capital of the province of Batina, on the sea of Oman, 125 m. N. W. of Muscat ; pop. about 20,000. It is surrounded by a wall, defended by a few guns. The castle, a handsome build- ing with three walls around it, occupies a low hill, from which an open space planted with trees extends to the sea. The market place is large and regular, and contains good shops. Many of the houses are of tAvo and three sto- ries and well built. The roadstead is well pro- tected, and offers good anchorage, but large vessels have to lie some distance off shore. Outside the walls is an open sandy space, but beyond it are gardens with shade trees and | running waters. The chief manufactures of the town are arms, stuffs of wool, cotton, and silk, carpets, and coverlets. Sohar once had a large trade, but it has been injured by the prosperity of Muscat, and many of its build- ings are now in a semi-ruinous condition. SOUL. See Z6LTOM.
