Page:Collier's New Encyclopedia v. 03.djvu/411

LEFT DIE 357 DIEPPE lanthanum and didymium as double sul- phates. Didymium can be separated from lanthanum by precipitating half the oxide with ammonia, and leaving the precipitate in contact with the solution; the lanthanum, being the stronger base, then passes into solution in predominant quantity. By repeating the process, the oxides being again dissolved and precipi- tated, the didymium oxide is obtained nearly pure. Didymium is a white met- al with a tinge of yellow; specific gravi- ty, 6.5. It tarnishes in dry air; it burns with great brilliancy when thrown into a flame. Its oxide, DisOs, is a dirty bluish color; the nitrate is obtained in large violet crystals by dissolving the oxide in nitric acid. The sulphate, Di2(S04)8 6HjO, forms rose-red crystals. The ox- alate is a crystalline powder. The spec- trum of a solution of a salt of didymium contains characteristic dark bands. In botany, the word is applied to a genus of gasteromycetous fungi, consist- ing of minute plants growing upon leaves, bark, rotten wood, etc., distin- guished by its double peridium. DIE, a word with various applications. (1) In punching-machines, a bed-piece which has an opening the size of the punch, and through which the piece is driven. This piece may be a planchet or blank, or it may be merely a plug driven out of the object to form a bolt or rivet hole. In nut-machines the nut- blanks may be made by one die and punched by another. (2) In forging, a device consisting of two parts which co-act to give to the piece swaged be- tween them the desired form. (3) In sheet-metal work, a former and punch or a cameo and intaglio die between which a piece of sheet-metal is pressed into shape by a blow or simple pressure. In coining, both dies are intaglio, so as to make a cameo or raised impression upon each face of the planchet. The upper die has the obverse, the face, which is often the bust of the sovereign or national emblem. The lower die has the reverse, with an effigy, legend, value, escutcheon, as the case may be. Owing to the random way in which ornaments are disposed on coins, any general defi- nition will no longer meet all cases. A die will sometimes deliver 250,000 im- pressions before it is necessary to re- move it from the coining-press; and sometimes a die will crack at the first impression. DIEGO GARCIA (dya'go gar-the'a), an island of the Indian Ocean, in lat. 7° S., and Ion. 72° — 73° E., extends in an irregular horseshoe shape, and is 30 miles long, embracing between its ex- tremities three minor islets (the Chagos Islands). It contains a spacious bay, and is very convenient for coaling pur- poses. The group has about 700 inhab- itants, and is a dependency of Mauritius. DIELMAN, FREDERICK, an Amer- ican painter; born in Hanover, Ger- many, Dec. 25, 1847; removed to the United States in childhood, and grad- uated at Calvert College. He was a topographer and draughtsman in the United States Engineer Department in 1866-1872. He studied art under Diaz at Munich, and established a studio in New York in 1876. He is a member of the National Academy and other art organizations; was the designer of the Mosaic panels, "Law" and "History" in the new Congressional Library at Washington, D. C. ; and was president of the National Academy of Design (1889-1902), Professor of Drawing, Col- lege of the City of New York (1903- 1918) and director of the Art School of Cooper Union. DIELYTRA, a genus of plants be- longing to the natural order FinnaH- acess, or Fumitories. The best known is D. spectabilis, a native of northern China and Siberia, now common in European and other gardens. It blos- soms in April and May, and its long drooping racemes of purplish-red blos- soms present a very graceful appear- ance. It grows freely in the open air. It is sometimes called pendent heart or virgin's heart, but is more commonly known as bleeding heart. DIEMEN, ANTON VAN. a Dutch ad- ministrator; bom in 1593. Having gone to India, he speedily rose to the highest dignities, and was at length, in 1636, made governor-general. He administered the government with much ability, and contributed much to the establishment of Dutch commerce in India. Abel Tas- man, whom he sent with a vessel to the South Seas in 1642, gave the name of Van Diemen's Land to the island now called Tasmania. Van Diemen died in 1645. DIEPPE (de-ep'), a seaport town of France, department of Seine-Inferieure, on the English Channel, at the embouch- ure of the Arques, 93 miles N. N. W. of Paris. Almost the only public edifices worth special notice are the two Gothic churches, St. Jacques, begun in the 13th century, and St. Remi, founded in 1522, and the old castle (1433), now a bar- rack. To the W. of Dieppe proper is the suburb La Barre ; and on the opposite side of the harbor La Pollet, inhabited chiefly by sailors and fishermen. The