224i Prof. Berzelius on Tfiorina and its Salts. 



when hot or cold, provided the earth has been previously per- 

 fectly free from oxide of iron. 



From titanic acid as well by its precipitating with sulphate 

 of potash, as by the characteristic properties of titanic acid be- 

 fore the blowpipe. 



From the common metallic oxides^ among which, from its 

 high specific gi*avity, it might be ranked by its not being pre- 

 cipitated by sulphuretted-hydrogen. 



; The properties which it possesses in common with the sub- 

 phosphate of yttria are the following : — \st^ Its salts have a 

 pure astringent taste. 2(i, The crystallized sulphate treated 

 .with warm water becomes opaque, and leaves a white skeleton 

 of the crystalline form. 3rf, Most of its salts are precipitated 

 by boiling, and attach themselves strongly to the sides of the 

 glass, like a white enamel. 4^A, Its hydrate strongly attracts 

 carbonic acid from the air while drying. 5th, And dissolves 

 in carbonated, but not in caustic alkalies. Qth, And the solu- 

 tions of both are precipitated by prussiate of potash, &c. 

 But it is easily distinguished from yttria both by the above- 

 mentioned test, and by this, — that the chloride of thorium is 

 not thrown down by boiling, like a solution of sub-phosphate 

 of yttria in muriatic acid. 



Salts of thorium. The salts which thorium gives, as well 

 with salt formers,* as in the state of oxide with the oxy-acids, 

 are distinguished by a strong and pure astringent taste, which 

 is not accompanied by any thing of sour, sweet, or bitter, and 

 which most resembles that of pure tannin. In taste they also 

 resemble nearest the salts of zirconium. Their solutions are 

 precipitated by oxalic acid, and by the cyanide of iron and 

 potassium, of a white colour ; and are rendered muddy by 

 sulphate of potash, which is dissolved by them. 



These three reagents distinguish them from all other un- 

 mixed salts except those of the protoxide of cerium, from 

 which salts they are distinguished by this, — that the colour- 

 less precipitate by caustic alkali does not become yellow in the 

 open air as is the case with the cerium salts. The salts of 



• The followinj^ are what Berzelius calls Salt bildare, salt-builders j chlo- 

 rine, iodine, bromine, cyanogen, fluorine, and sulpho- cyanogen, the base 

 of the hydio-sulpho-cyanic acid. — Translator. 



