150 



Mr. N. Story-Maskelyne on the 



[Jan. 13, 



Osborne and in commemoration of the important service that gentleman 

 rendered to science in preserving aud transmitting to London in its entirety 

 the stone which his zeal saved at the time of its fall. 



That the octahedra of Osbornite are regular was proved by angles of 

 even such microscopic crystals giving measurements over the edges and 

 solid angles that accorded within 3' with those of the regular octahedron. 



The crystals are brittle, and their powder retains the beautiful yellow 

 colour of the surface, which is therefore intrinsic, and not a tarnish. 

 The amount of them available for analysis being so minute, their chemical 

 examination was attended with much difficulty. Boiled for a long time in 

 the strongest hydrogen chloride, they were unchanged, and hydrogen 

 fluoride was apparently without action on them. They passed unscathed 

 through a fusion with potassio-sodium carbonate. 'When heated on a 

 splinter of porcelain in a current of dry chlorine, the crystals glowed for a 

 few seconds, lost their metallic lustre, and became of a honey-yellow 

 colour, while a white sublimate formed on the walls of the tube. Exposed 

 to the air, the altered crystals deliquesced, and assumed a pasty consist- 

 ence ; in water they dissolved partially, forming an alkaline solution, in 

 which ammonium oxalate produced a precipitate. The insoluble portion 

 was taken up for the most part by hydrogen chloride, and its solution gave 

 a decided precipitate with the above reagent. The water through which 

 the chlorine was allowed to escape, and the sublimate in the tube, after 

 treatment with hydrogen chloride, were taken together, and found, on 

 examination, to give a white precipitate with barium chloride, the filtrate 

 from which, after the excess of barium had been removed, furnished with 

 ammonia a precipitate resembling alumina, which, however, was insoluble 

 in potash, and was thrown down from slightly acid solutions with sodium 

 hyposulphite, and potassium sulphate. It was examined for titanic acid 

 by means of magnesium wire in a slightly acid solution, but with a nega- 

 tive result. The only alternative left was to conclude that the substance 

 which exhibited this deportment was either titanium or zirconium, and 

 that the gold-like crystals were a combination of this element with calcium 

 (perhaps a little iron) and sulphur in some remarkably stable form. That 

 this mineral should be a compound of the sulphides of these metals merely 

 is scarcely conceivable when its power to withstand the action of acids is 

 considered ; possibly its composition, if it could be quantitatively ana- 

 lyzed, would be found to be that of a compound of titanium or zirconium 

 and calcium of the obscure kind that is known as an oxysulphide. 



Mr. Sorby, who has made the zirconium and titanium group of metals 

 the subject of special study, formed a microscopic borax bead, into which 

 he introduced some of the oxide obtained from the Osbornite. He found 

 it to behave as titanic acid. 



The occurrence of Osbornite occasionally in the augite presently to be 

 described, and the fact of the latter mineral lying chiefly in that part of the 

 meteroite where the Osbornite is found, suggested the possibility of the 



