THOR THORNTON. 



605 



casionally observed, whose form is that of a right 

 square prism. It is colourless and translucent in 

 the mass ; but small fragments are transparent. It 

 possesses considerable lustre, approaching to pearly, 

 is brittle, arid scratches flu or. Its crystals do not 

 cleave parallel to the terminating planes of the 

 prism. It consists of 



Silex 3680 



Alumine, . . . . .-31-36 



Lime, 15 40 



Magnesia, 020 



Peroxide of iron 60 



Water, 13-00 



Before the blow-pipe, it swells, curls, and becomes 

 snow-white and opaque, but does not melt. When 

 exposed to a red heat, it becomes opaque, very white, 

 and shining like enamel : the edges are rounded, but 

 it does not altogether lose its shape, but loses 13 

 per cent. It occurs at Kilpatrick, near Dumbarton, 

 Scotland, also in Nova Scotia, in trap. 



THOR, OR TIR ; the Jupiter of the Germans : 

 the God of thunder. He was represented as an old 

 man with a long beard, a crown with diverging rays, 

 dressed in a long garment, holding in his right hand 

 a sceptre with a lily, and having around his head a 

 circle of stars. Sacrifices were offered to him un- 

 der oaks ; hence the German name, thunder-oak. 

 Boniface (q. v.) felled the Thor-oak near Geismar. 

 TTiursday (day of Thor) has its name from him. 



THORA. Bee Tora. 



THORIUM. In the year 1815, Berzelius sup- 

 posed that he had discovered a new earth among 

 the ingredients of the Gadolinite, to which he gave 

 the name thorina ; but he afterwards ascertained 

 that this substance was a phosphate of yttria. In 

 1828, he received from professor Esmark of Chris- 

 tiania in Norway, a black mineral, like obsidian, 

 and having a specific gravity of 4-63. To this mi- 

 neral Berzelius gave the name of thorite. It was 

 discovered in sienite, in the isle of Lor-on, near 

 Brevig, in Norway, and is very scarce. The mineral 

 has the following composition : 



Thorina, 5791 



Lime 2-58 



Peroxide of iron 3'40 



Deutoxide of manganese, . . 2-39 



Magnesia, 0'36 



Peroxide of uranium, . . T61 



Protoxide of lead 0-80 



Oxide of tin 0.01 



Silex 18-98 



Water, 9-50 



Potash, 0-14 



Soda, 0-10 



\lumine, ... . . O'OG 



Undecomposed matter, . . 1-70 



99-54 



To obtain thorina from this mineral, it was reduced 

 to powder and digested in muriatic acid. The mu- 

 riatic solution, after the separation of the silex, was 

 precipitated by caustic ammonia, which threw down 

 the thorina, still contaminated by various impurities. 

 By a variety of operations, it was separated from 

 these, with the exception of a small quantity of 

 oxide of manganese, which it was impossible to get 

 rid of. When mixed with charcoal powder, and 

 heated to redness in a porcelain tube, while a cur- 

 rent of dry chlorine is made to pass over it, chlo- 

 ride of thorium is obtained. When this chloride is 

 heated with potassium, a slight detonation takes 

 place, and a dark-gray matter is obtained. When 

 washed with water, a little hydrogen gas is given 

 out, the chloride of potassium dissolves, and the 

 thorium is left in a powder, having an iron-gray 

 colour and metallic lustre. Like aluminum, it ap- 



pears to be malleable. It is not oxidized by water, 

 even when assisted by heat. When gently heated 

 in the open air, it takes fire, and burns with very 

 great splendour, being converted into thorina. The 

 earth thus formed is snow-white, and exhibits no 

 traces of fusion, notwithstanding the very high 

 temperature during the combustion. When tho- 

 rium is put into dilute sulphuric acid, a strong ef- 

 fervescence with the disengagement of hydrogen 

 gas, takes place at first ; but this soon stops, even 

 though the liquid be heated. Nitric acid acts upon 

 thorium with still less energy than sulphuric acid, 

 but muriatic acid dissolves it rapidly, with the evo- 

 lution of hydrogen gas. Thorium is not acted on by 

 the caustic alkalies. The only compound which 

 thorium seems capable of forming with oxygen is 

 thorina. To obtain this substance in the state of a 

 hydrate, we have only to add caustic potash to the 

 solution of thorina in an acid. Hydrate of thorina 

 is gelatinous, and contracts while drying. When 

 moist, it dissolves readily in acids : but it is much 

 less soluble \vhen dry. The salts which it forms 

 have a styptic taste. This hydrate is insoluble in 

 the caustic alkalies ; but it dissolves in the carbo- 

 nates. It is more soluble in cold than in hot car- 

 bonate of ammonia. Thorina is distinguished from 

 the other earths by the following property ; its sul- 

 phate is precipitated from its solution by raising it 

 to a boiling temperature, and dissolves again, though 

 slowly, in cold water. The salts of thorina are not 

 of sufficient importance to require description. 



THORLACIUS (THORLAKSEN), SKULE and 

 BORGE ; father and son. Skule Thordsen, the for- 

 mer, was born in Iceland, in 1741, and died at Co- 

 penhagen, in 1815, where he was rector of the 

 Latin school. Besides his participation in the 

 Heimskringla, his preface to the first part of the 

 Saemundic Edda, and some short Essays upon Thor, 

 two Runic stones, &c., he was the author of a va- 

 luable work entitled Antiquitatum Borealium Ob- 

 servationes (Copenhagen, 1778 99), and of com- 

 mentaries upon the Hakonar-Quida, the Grotta- 

 Savngr, the Havstlavng, &c. The son, born at Col- 

 burg, in 1775, professor of theology at Copenhagen, 

 has also thrown much light on northern antiquities 

 and literature, by several works ; he likewise fur- 

 nished the means of completing the publication of 

 the Heimskringla, and of the Saemundic Edda, which 

 had been delayed for thirty years. 



THORN ; a town in the Prussian government of 

 Mariemverder, province of West Prussia, on the 

 Vistula, about 90 miles from its mouth ; 100 miles 

 north-west of Warsaw ; Ion. 23 48' E. ; lat. 53 

 1' N. ; population 9000. It consists of the old and 

 new town, separated from each other by a wall and 

 ditch ; both surrounded by a mound and moat. 

 Thorn was formerly considered a place of great 

 strength. It contains one Lutheran and three Ca- 

 tholic churches, two convents, a Catholic gymna- 

 sium, and a military academy, and some manufac- 

 tures ; but its commerce is less than formerly, the 

 Vistula having become more shallow, so that vessels 

 of burden can no longer come up to the town. (See 

 Vistula.') It was formerly distinguished among the 

 Hanse towns. Copernicus was born here in 1472. 



THORN APPLE. See Stramonium. 



THORNTON, BONNELL, a miscellaneous writer 

 of genuine humour, the son of an apothecary, was 

 born in London, in 1724, and studied at Oxford. 

 In 1750, he studied physic, but soon after united 

 with the elder Colman in the establishment of the 

 amusing periodical paper entitled the Connoisseur. 



