GOG TITANIUM. 



the pins introduced at the boiling temperature. The pins un- 

 dergo no change in this liquor, supposing it to contain no im- 

 dissolved tin, but the moment a fragment of tin touches the 

 pins, all those in contact with each other are tinned. 



SECTION II. 



TITANIUM. 

 Eq. 303.7 or 24.33 5 Ti. 



This metal was discovered in 1791, by Mr. Gregor of Corn- 

 wall, and afterwards by Klaproth who gave it the name tita- 

 nium. In the form of titanic acid it constitutes several mine- 

 rals, as rutile, anatase, menachanite, etc ; and as titanate of 

 protoxide of iron, ilmenite and other species. 



Titanic acid, mixed with one-sixth of its weight of charcoal 

 powder, may be reduced by the most intense heat of a wind 

 furnace, which does not, however, fuse the titanium. It is 

 frequently found in small cubic crystals of a bright copper 

 colour, on the slag which adheres to the lower part of the iron 

 smelting furnaces. The iron and foreign matter of the slag may 

 be removed by digestion in acids, and the crystals obtained in 

 a separate state. Their density is 5.3 ; they are harder than 

 quartz. Titanium is not dissolved by any acid, except a mix- 

 ture of nitric and hydrofluoric acids. It is slowly oxidated in 

 fused nitre. Titanium combines in two proportions with oxy- 

 gen, forming titanic oxide TiO, and titanic acid TiO 2 . 



Oxide of titanium, TiO, 403.7 or 32.33. Is formed when 

 titanic acid is exposed in a charcoal crucible, to the highest 

 temperature of a wind furnace. Where the acid was in contact 

 with the charcoal, a thin coating of red metallic titanium is 

 formed, but within, it is changed into a black mass, which is 

 insoluble in all acids, and not otherwise affected by them, is 

 oxidated with difficulty when heated in contact with air, or by 

 fusion with nitre. The oxide of titanium is also obtained by 

 the moist way, in the form of a deep purple powder, when a 

 fragment of zinc or iron is introduced into a solution of titanic 

 acid in hydrochloric acid, but alters so quickly by absorption of 

 oxygen, that an opportunity has not been obtained of studying 



