SERAPIS
1725
SERUM
are S. sempervirens, the true redwood, and 5. gigantea, the giant redwood. The former grows only in the Coast Ranges, and is abundant enough to be a very important lumber tree. The recorded sizes are from 50 to 75 feet in circumference and 200 to 300 feet in height. It is one of the most important timber-trees in the world. The Pacific coast is supplied by the redwood with much of its building and fencing lumber. The tree does not thrive away from the sea-fog, all redwood forests being in a strip 20 to 25 miles wide and in length 500 miles. It has marvelous reproductive powers; persistently throws up shoots when cut or fallen, resists fire well, and quickly makes new forests. The giant redwood occurs in groves in a narrow strip along the western slope of the Sierra Nevada. Among the most famous groves are those of Calaveras County and the Mariposa grove just south of the Yosemite. The latter contains one of the largest standing trees, known as the Grizzly Giant, whose trunk at the ground is more than 93 feet in circumference. The age of the largest trees is from 2,000 to 2,500 years. In former ages sequoias were widely distributed throughout the world. As the last survivors of a very ancient and wonderful family, as well as for their own majesty, they are of the greatest interest and value. Nevertheless, many of the giant redwoods of private ownership have been sacrificed for money. A recent benefaction of a public-spirited citizen, William Kent of Chicago, has provided for the preservation, some few miles out from San Francisco, of a tract heavily wooded with virgin timber, chiefly redwood and Douglas fir. Mr. Kent purchased the forest with the purpose of having it established as a government reserve, and in January of 1908 the government accepted the generous offer; and Muir Woods, the name given to the beautiful canon forest by the donor, now belong to the nation. See FOREST-RESERVES and MUIR, JOHN.
Sera'pis, the Greek name of an Egyptian god, introduced into Egypt in the time of Ptolemy Soter. He was a combination of the Greek Hades and the Egyptian Osiris. It is said that 42 temples were built for the worship of this god, though they were admitted only into the Greek cities founded in Eg^ypt. The best known of these temples was the magnificent Serapeum at Alexandria, to which was joined the celebrated Alexandrine Library. Antoninus Pius introduced the worship of Serapis into Rome, but it was soon abolished. Many Roman coins hav s his image joined to that of Isis. The worship of Serapis ceased in Egypt only when his image in Alexandria was destroyed by its Christian archbishop in 398 A. D.
Serf. See SLAVERY.
Ser'pentine, a mineral made up of silica, magnesia and water, with a little protoxide of iron. Serpentine is usually found in masses, never in crystals; is generally some shade of green, but sometimes is red or brownish-yellow; and feels smooth, but often greasy. Precious or noble serpentine is a rich, dark green, hard enough to take a good polish, translucent and sometimes having garnets imbedded, which form red spots and add to its beauty. It is a rather rare mineral, and is found at Baireuth (Germany), in Corsica and in the Shetland Islands. The Romans made of it beautiful pillars; and boxes, vases etc. are still cut from it. Marmolite is a scaly serpentine; chrysolite is a kind with delicate fibers and a silky luster. Common serpentine is a rock rather than a mineral. Its name comes from its being often marked with winding veins. Its color usually is green or red, often mottled, veined or clouded.
Ser'pents. See SNAKES.
Serpent - Wor'ship is one of the oldest forms of religion, and still exists among many^ savage peoples. Serpent-worship is prominent in Hinduism. We see traces of it in the great serpent which defended the citadel of Athens, fed every month with honey-cakes. Among Zulus harmless green or brown snakes which come boldly into the houses are thought to be ancestors, and are often identified by some scar or mark, such as the man bore in life. Serpents are often looked upon as the embodiment of gods, as was the rattlesnake worshiped in the Natchez temple of the Sun; the Phoenician serpent with its tail in its mouth, an emblem of eternity. Reverence for the serpent is notable among the American Indians, where its name has been given to rivers, as the Kennebec and the Antietam. Among the Dakptas, Shawnees and Sacs the words for spirit and snake are similar. The Algonquins think the lightning a huge snake, and the Caribs speak of the god of the thunder-storm as a mighty serpent. The Ojibways dread to kill a rattlesnake, and, if they find one in their path, beseech it to go away and spare them and their families. The same worship is found among the Cherokees and other tribes as well as in the strange snake-dances of the Zunis. See Fergusson's Tree and Serpent Worship.
Se'rum. The blood in the bloodvessels consists of two parts: the solid, which includes both kinds of corpuscles, and the liquid, called the plasma. When blood escapes from the bloodvessels, it first becomes viscid or like a jelly. If this jelly-like mass is left standing some time, it separates into two parts, a liquid, which is the serum, and a solid clot which floats upon the serum. Now, the clot is found to contain practically all the corpuscles and also a network of fine threads called fibrin. Hence, as the cor-
