TITANIUM. 



aarcoal. A blaekilh bliftered fubllance is obtained, which 



as a reddith colour in fome points. According to Lampa- 

 Jius, its colour rofembles that of copper, but is deeper, and 

 the luftre is confiderablc. It is brittle, but when in thin' 

 plates, its eiaftlcity is confiderable, r 



When titanium is boiled witii nitric acid, no remarkable 

 efFeft enfues, but the briglit fpots difapprar, and are fuc- 

 ceeded by a white compound. Nitro-niuriatic acid forms 

 alfo a white powder, which remains fufpended in it. Sul- 

 phuric acid exliibits a fimilar appearance, fulphurous acid 

 is difengagcd, and the titanium is partly changed to a white 

 oxyd, and partly diflblved. Muriatic acid ditTolves tita- 

 nium, but not its oxyd. 



The folution of titanium gives a white precipitate with 

 alkaline carbonates, a grafs-green mixed with brown with 

 pruffiate of pota(h, and a dirty dark green with the hydro- 

 fulphurets. Infufiou of galls precipitates a reddifh-brown 

 fubllance, which, if the folution be concentrated, has the 

 appearance of blood. A rod of tin immerfed in the folu- 

 tion imparts to the liquid round it a fine red colour, and a 

 rod of zinc a deep blue. 



Titanium tarniflies by expofure to the air, and is oxy- 

 dized when heated in contaA with it. It can exift in three 

 ftates of oxydation ; the firll is blue or purple, the fecond 

 red, and the third white. The white oxyd is the only one 

 the compofition of which is accurately known. It has 

 been (liewn by Vauquelin and Hecht to confift of eighty 

 parts of red oxyd, and eleven of oxygen. Titanium has 

 not yet been combined with fulphur, but has been com- 

 bined by Mr. Chenevix with phofphorUs. 



The only alloy of any confequence which it forms is with 

 iron ; it is of a grey colour, interfperfed with brilliant par- 

 ticles, and is quite infufible. The above are the principal 

 properties of this metal which have yet been difcovered : 

 it has not hitherto been applied to any ufeful purpofe in the 

 arts. 



The ores of titanium have been divided into fix fpecies 

 by mineralogifts ; viz. menachanite, iferine, nigrine, fphene, 

 rutile, and oftahedrite. 



Menachanite is fo called from the valley of Menaian, in 

 Cornwall, where it was originally foimd. It occurs alfo 

 on the (hores of the ifland of Providence, and in the vici- 

 nity of Richmond, in the United States of America ; and 

 alfo at Botany Bay, in New South Wales. It is found in 

 fmall angular grains, which are of a greyifli or iron-black 

 colour, and have a rough glimmering furface. From its 

 appearance it has been confounded with iron-fand, but its 

 magnetic attraftion is much v.-eaker : it is lefs hai-d, and may 

 be diftinguilhed by its frafture, and particularly by the 

 lufti-e, which approaches to femi-metallic. The fraAure is 

 imperfeftly foliated : the fragments are angulai' and fharp- 

 edged, and it is pcrfeftly opaque. It yields to the knife, 

 retaining its colour in the (Ireak. It is opaque and brittle. 

 The fpecific gravity, according to Gregor, is 4.427 ; but as 

 given by Lampadius, is 4.270. Menachanite is infufible by 

 the blowpipe without addition, but tinges borax of a 

 greenifh-brown colour. Its conlUtuent parts, according to 

 Klaproth, are 



Cornivall. 



Oxyd of iron 

 Oxyd of titanium 

 Oxyd of manganefe 

 Silex 



5 1. CO 



45-25 

 0.25 



3-50 



100 



Botany Bay, 



According to Chenevix : 



Oxyd of iron 



Oxyd of titanium - 



Silex ... 



49 

 40 

 II 



lOO 



Ifcnne is fo called from having been originally found near 

 the fource of the river Ifer, in Silefia: it is dilfeminated in 

 granitic fand, with iron-fand. It occurs alfo with fimilar 

 fand in the bed of the river Don, in Aberdeenfhire. It is 

 fufpeAed by profelfor Jamefoii to be afTociated with trap, 

 rocks ; and from the obfervations of M. Cordier, that it is 

 found as a conllituent part of lava, this opinion is rendered 

 the more probable. Iferine is of a brownifli iron-black colour. 

 It is found in fmall grains and rolled pieces, with a rough 

 and glinimeriiig furface. The internal luftre is femi-nwtallic. 

 Its frafture is conchoidal, which diilinguifhes it from mena- 

 chanite, to which it bears a near refeniblance. The fpe- 

 cific gravity is 4.5. Before the blowpipe it melts into a 

 blacki ill -brown coloured glafs, which is fliglitly attrafted 

 by the magnet. The mineral acids have no fenfible effeft 

 on it, but the acid of fugar extrafts a portion of the 

 titanium. According to Dr. Thompfon, its conftituent 

 parts are 



Oxyd of titanium - - 48 

 Oxyd of iron - - 48 



Oxyd of uranium - - 4 



Nigrine ; Titane oxycle ferrifere of Haiiy, is fo called on 

 account of its colour, which inclines to a velvet -black. It 

 occurs, like the preceding fpecies, in angular grains and in 

 rolled pieces. The external luftre is ghftening, that of the 

 frafture fhining : the ftrufture is imperfeSly foliated. It is 

 opaque, and harder than menachanite. Nigrine is brittle, and 

 gives a yellowifti ftreak. The fpecific gravity varies from 

 3.700 to 4.740. It is not attrafted by the magnet, and is 

 infufible by the blowpipe, but with the addition of borax 

 melts to a tranfparent hyacinth red globule. The acid of 

 fugar extrafts the titanium from this ore. It is found in 

 alluvial ground in Tranfylvania, Bavaria, and the ifland 

 of Ceylon : it occurs alfo in the granite of the Uralian 

 mountains. 



The conftituent parts of nigrine are given as tinder : 



Tranfylvai 



Oxyd of titanium 

 Oxyd of iron 

 Oxyd of manganefe 



Klaproth. 

 84 



14 



2 



100 



The Uralian Mountains. 



Oxyd of titanium 



Oxyd of iron ... 



Low it z. 



53 



47 



100 



Vol. XXXV. 



OUahedrite ; Scharl l!eu, Rome de Lifie ; Titaite anatafe, 



Haiiy. This ore of titanium is fo called from its conftant 



occurrence in cryftallized forms, which are varieties of the 



4 Z odlaliedron. 



