EARTHS. 299 



(e.) Combines with potassa and soda, but not with ammonia, al- 

 though it is soluble in the carbonate of that, and of other alkalies, and 

 in the caustic fixed alkalies. 



(/*.) With all the acids forms salts, with a sweetish astringent taste ; 

 they are decomposed by the alkalies, even by ammonia, which does 

 not precipitate alumina, which glucina considerably resembles. 



(g.) Resembles alumina in attracting coloring matter. 



(A.) It is not precipitated by prussiate of potash. 



(i.) It absorbs carbonic acid, at the ordinary temperature of the 

 air. 



4. COMBINING WEIGHT. Stated by Dr. Thomson, and by Ber- 

 zelius as 26. 



5. POLARITY. From analogy supposed to be electro positive. 



GLUCINIUM. 



1. This base has not been distinctly obtained, but the analogy 

 which would lead us to admit its existence, is strongly supported by 

 the following fact. 



2. Sir H. Davy ascertained that by igniting potassium with glu- 

 cina, the metal is converted into potassa, thus proving the existence 

 of oxygen in the earth ; dark colored particles, with a metallic aspect 

 also appeared in the mass, and regained the earthy character by be- 

 ing heated in the air, and by the action of water, hydrogen gas being, 

 in the latter case, evolved. 



3. COMBINING WEIGHT. Dr. Thomson concludes that the num- 

 ber for the earth must be 26, and if it consists of 1 proportion of me- 

 tallic base, and 1 of oxygen, the latter being 8, the former will of 

 course be 18.* 



4. POLARITY. Supposed from analogy to be electro positive. 



SEC. IX. YTTRIA. 



1. NAME NAT. HISTORY DISCOVERY. 



Name, from Ytterby, a quarry in Sweden, where the mineral was 

 found, from which Yttria was first extracted. 



Discovered by Prof. Gadolin, in 1794, during his analysis of this 

 mineral, called after him, the Gadolinite, and confirmed by several 

 eminent chemists since. 



Yttria has been found, not only in the mineral mentioned above,-)" 

 which yielded it in the proportion of 35 to 45 per cent., but also in 

 another mineral, consisting of the metal tantalum, and yttria, called 

 yttrotantalite, containing about 20 per cent., and in the yttrocerite, 

 which has about 8 or 9 per cent. These minerals, as well as Ga- 

 dolinite are found only in the quarry of Ytterby. 



2. PROCESS. 



* Thomson's First Principles, Vol. I, p. 318. 

 t Combined with black oxide of iron and silica. 



