626 SAP SAPPHIRE capital. II. A city of the preceding province, near the mouth of the Rio Grande do Sul, 150 m. . S. W. of Porto Alegre ; pop. about 18,000. The streets are irregular, but well paved. The harbor is the only good one in the province, nearly the entire trade of which, conducted mainly by English and Germans, centres here. Three lines of steamers run to Porto Alegre. The exports in 1872-'3 were valued as follows: hides, $5,037,312; horse- hair, $247,200 ; wool, $149,544 ; mat6 or Para- guay tea, $93,658 ; rum, sugar, coffee, and timber, $6,897; total, $5,534,611. The im- ports amounted to $1,826,587. The arrivals from foreign ports were 929 vessels, tonnage 198,029; departures 698, tonnage 212,936; arrivals from Brazilian ports 840, tonnage 221,213; departures 890, tonnage 185,060. SAP. See PLANT, vol. xiii., p. 582. SAPAJOU. See MONKEY, vol. xi., p. 751. SAIMV WOOD (Malay, sapang), a dyewood afforded by Ccetalpinia apan, imported from the East Indies and used to dye red on cotton. The genus, named in honor of the naturalist Ctesalpinus, is also found in Central and South America and the West Indies, where some species afford Brazil, peach or Nicaragua, and other dyewoods (see BRAZIL WOOD), and an- other species the divi-divi pods used in tan- ning (see DIVI-DIVI). SAPOR. See PERSIA, vol. xiii., p. 322. SAPPIIIRE (Hob. appir; Ar. saftr a pre- cious stone, next in value and hardness to the diamond. It is a transparent variety of corun- dum, composed of nearly pure alumina. It re- ceives different names according to the color, the red sapphire being the oriental ruby ; the amethystine, the oriental amethyst; the yel- low, the oriental topaz; the green, the orien- tal emerald ; while the term sapphire alone is commonly applied to the blue variety. The Greek sapphire (oAxfetpof) was not the gem here described, but the lapis lazuli, as appears from the description given by Theophrastus and Pliny. The blue sapphire is the v&KtvOof of the Greeks and the hyacinthu* of Pliny. The ruby was probably included in the an- thrax of Theophrastus and the earbunculu and lychnis of Pliny. The chemical formula of sapphire is A1 4 O, with a small quantity of oxide of chromium, upon the varying propor- tions of which the color of the different varie- ties depends. The coarser kinds of corundum contain several other oxides. (See CORUNDUM, and EMERY.) The sapphire crystallizes in the rhombohedral system, has a vitreous lustre, often pearly in the basal planes, and some- times, when viewed in the direction of the vertical axis, exhibits a bright opalescent star. All sapphires, or pure varieties of corundum, are exceedingly tough and hard, being rated 9 on the scale of hardness, the diamond being 10. The gem is found in various parts of the world, and in different geological formations, as in the granite of Siberia, in the ripidolite of North Carolina, and in the granular lime- stone of New Jersey. The finest ruby sap- phires come from Pegu, Burmah, and Siam. Smaller ones have been found at Hohenstein in Saxony, Bilin in Bohemia, and Le Puy in France. The finest blue sapphires come from Ceylon. The blue sapphire has been known from the earliest times, and was regarded by the ancients as a sacred stone. It is the fifth stone in the breastplate of the Hebrew high priest. A good blue sapphire of 10 carats is worth about 50 guineas, and one of 20 carats 200 guineas. An ordinary rule for estima- ting the value is to multiply the square of the weight in carats by half a guinea. Fine gems, for special reasons, often bring a much higher price ; thus a sapphire of a barbel blue, weighing 6 carats only, brought at a public sale in Paris $350. Notwithstanding its ex- cessive hardness, the ancients executed fine engravings upon the sapphire. A remarkable intaglio by Cneius, cut in a sapphire, is in the Strozzi cabinet at Rome ; it is a profile of the yonng Hercules. The red sapphire, or ruby, is the most precious variety, a perfect one weighing more than 8$ carats being more val- uable than a diamond of the same weight ; a perfect one of 5 carats is worth twice as much as a diamond of the same weight ; and when they weigh 10 carats each, the ruby, if very fine, has three times the value of the diamond. According to Harry Emanuel (" Diamonds and Precious Stones," London, 1878), the finest and purest rubies have the following value : 1 carat, from 14 to 20; 2 carats, 70 to 80; 8 carats, 200 to 250 ; 4 carats, 400 to 450. The tint of the ruby is as fine by artificial light as by the light of day, and when of the finest tint it has the color of the centre of the red band of the solar spectrum, or that particular shade known by jewellers as " pigeon's blood ;" but it varies from the lightest rose tint to the deepest carmine. A deep-colored ruby ex- ceeding 20 carats is usually called a carbuncle. The largest fine ruby known in the world was brought from China to Prince Gagarin, gov- ernor of Siberia ; it afterward came into the possession of Prince Menshikoff, and is now in the imperial crown of Russia. The mines of Burmah are a royal monopoly, and the finest stones can bo carried out of the country only by smuggling. When a particularly large and fine stone is found, it is customary to send out a procession of grandees with soldiers and elephants to meet it. One of the titles of the king is " lord of the rubies." The yellow sapphire, called the oriental topaz, is very rare, but never reaches the value of a ruby or blue sapphire, or even an emerald of equal dimen- sions. It was the second stone in the breast- plate of Aaron. It was for a long time sup- posed that the ancients did not engrave upon the topaz, but Caire describes one in his pos- session weighing 29 carats, engraved with the motto in Arabic, " No one accomplishes but God." The ordinary occidental topaz is a compound of alumina, silica, and fluoric acid.
