Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

LANTERNS OF THE DEAD

Online Encyclopedia
Originally appearing in Volume V16, Page 188 of the 1911 Encyclopedia Britannica.
» Make a correction to this article.
» Add information or comments to this article.
Spread the word: del.icio.us del.icio.us it!

LANTERNS OF THE DEAD , the architectural name for the small towers in See also:

stone, found chiefly in the centre and See also:west of See also:France, pierced with small openings at the See also:top, where a See also:light was exhibited at See also:night to indicate the position of a See also:cemetery. These towers were usually circular, with a small entrance in the See also:lower See also:part giving See also:access to the interior, so as to raise the lamps by a See also:pulley to the required height. One of the most perfect in France is that at Cellefrouin (See also:Charente), which consists of a See also:series of eight attached semicircular shafts, raised on a See also:pedestal, and is crowned with a conical roof decorated with See also:fir cones; it has only one See also:aperture, towards the See also:main road. Other examples exist at Ciron (See also:Indre) and Antigny (See also:Vienne). 187 1: ;It 0muikTik I If ~f 'IC „', :1' I .~T h!C~ J , J 1j, Iy — in. u91 111111 iMiliBlbl lllp d ~, ~ `°°~1 Il t L I III IIItll96 See also:Lantern of the Dead at Cellefrouin (Charente). . LANTHANUM [See also:symbol La, atomic See also:weight 139•o (0=16)1 one of the metals of the See also:cerium See also:group of rare earths. Its name is derived from the Gr. XavOaveiv, to See also:lie hidden. It was first isolated in 1839 by C. G. Mosander from the " cerium " of J. See also:Berzelius.

It is found in the minerals gadolinite, cerite, samarskite and fergusonite, and is usually obtained from cerite. For details of the complex See also:

process for the separation of the lanthanum salts from cerite, see R. See also:Bunsen (Pogg. See also:Ann., 1875, 155, p. 377); P. T. Cleve (See also:Bull. de la See also:sac. chim., 1874, 21, p. 196) ; and A. v. Welsbach (Monats. f. Chem., 1884, 5, p. 5o8). The See also:metal was obtained by Mosander on See also:heating its chloride with See also:potassium, and by W.

F. See also:

Hillebrand and T. See also:Norton (Pogg. Ann., 1875, 156, p. 466) on See also:electrolysis of the fused chloride, while C. Winkler (Ber., 189o, 23, p. 78) prepared it by heating the See also:oxide with a mixture of See also:magnesium and See also:magnesia. Muthmann and See also:Weiss (Ann., 1904, 331, p. 1) obtained it by electrolysing the anhydrous chloride. It may be readily hammered, but cannot be See also:drawn. Its specific gravity is 6.1545, and it melts at 81o°. It decomposes See also:cold See also:water slowly, but hot water violently.

It See also:

burns in See also:air, and also in See also:chlorine and See also:bromine, and is readily oxidized by nitric See also:acid. Lanthanum oxide, La203, is a See also:white See also:powder obtained by burning the metal in See also:oxygen, or by ignition of the carbonate, nitrate or sulphate. It combines with water with See also:evolution of See also:heat, and on heating with magnesium powder in an See also:atmosphere of See also:hydrogen forms a hydride of probable See also:composition La2H3 (C. Winkler, Ber. 1891, 24, p. 890). Lanthanum hydroxide, La(OH)3, is a white amorphous powder formed by precipitating lanthanum salts by potassium hydroxide. It decomposes ammonium salts. Lanthanum chloride, LaCl3, is obtained in the anhydrous See also:condition by heating lanthanum ammonium chloride or, according to C. Matignon (Compt. rend., 1905, 40, p. 1181), by the See also:action of chlorine or hydrochloric acid on the See also:residue obtained by evaporating the oxide with hydrochloric acid. It forms a deliquescent crystalline See also:mass.

By evaporation of a See also:

solution of lanthanum oxide in hydrochloric acid to the consistency of a See also:syrup, and allowing the solution to stand, large colourless crystals of a hydrated chloride of the composition 2LaC13.15H20 are obtained. Lanthanum sulphide, La2S3, is a yellow powder, obtained when the oxide is heated in the vapour of See also:carbon bisulphide. It is decomposed by water, with evolution of sulphuretted hydrogen Lanthanum sulphate, La2(SO4)3.9H20, forms six-sided prisms, isomorphous with those of the corresponding cerium See also:salt. By careful heating it may be made to yield the anhydrous salt. Lanthanum nitrate, La(NO3)3.6H20, is obtained by dissolving the oxide in nitric acid. It crystallizes in plates, and is soluble in water and See also:alcohol. Lanthanum See also:carbide, LaC2, is prepared by heating the oxide with carbon in the electric See also:furnace (H. See also:Moissan, Compt. rend., 1896, 123, p. 148). It is decomposed by water with the formation of See also:acetylene, methane, See also:ethylene, &c. Lanthanum carbonate, La2CO3.8H20, occurs as the rare See also:mineral lanthanite, forming greyish-white, See also:pink or yellowish rhombic prisms. The atomic weight of lanthanum has been determined by B.

Brauner (Prot. Chem. See also:

Soc., 1901, 17, p. 63) by ignition of lanthanum sulphate at 5oo° C., the value obtained being 139 (O =16).

End of Article: LANTERNS OF THE DEAD

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.
Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
LANTERN (an adaptation of the Fr. lanterne from Lat... 		[next]
LANUVIUM (more frequently Lanivium in imperial time...

Site © 2006 - Net Industries