826 



YTTRIUM. 



heavy powder, which, if pure, is of a yellowish 

 white. Yttria is a strong base. Its crystalline 

 hydrated salts have all a pale rose color. 



The raetal, obtained by reduction from a 

 chloride with sodium, appears when dry as a 

 blackish-gray powder: its equivalent is given 

 by Popp as 34. It oxidizes in water, and more 

 rapidly on boiling. Heated on platinum foil, it 

 burns with an intense light the color not so 

 pure a white as that afforded by magnesium or 

 aluminium, but inclining to reddish. This met- 

 al, in fact, shows much analogy with magne- 

 sium, as also do its compounds with those of 

 the latter. The author, of course, concludes 

 that the supposed elements, erbium and terbium, 

 have no real existence. (Original paper in Ann. 

 der Ghem. und Pharm., Iv. 179.) 



M. Marc Delafontaine, on the contrary, has 

 contributed to the Archives des Sciences, etc., 

 Geneva, an account of his researches on the 

 yttria bases a translation, entitled "On the 

 Metals in Cerite and Gadolinite," appearing in 

 the Chemical News, April 7, 1865, etc., in 



which, while alluding to Popp's results, then 

 just published, he maintains the opposite view. 

 He briefly recounts how M. Gadolin in 1794 

 extracted the impure earth yttria from the pe- 

 culiar black mineral (Gadolinite) of the Ytterby 

 quarries ; while subsequently, out of, or as asso- 

 ciated with this earth, Ekeberg, in 1802, sepa- 

 rated the metal glucinum ; Berzelius, in 1815. 

 cerium; Mosander in 1839, lanthanium and 

 didymium ; ana the same chemist, in 1843, as 

 he supposed, erbium and terbium. M. Delafon- 

 taine considers at length the chemical reactions 

 and physical qualities of compounds accredited 

 to the last two, and of those of yttrium and the 

 other associated metals, besides presenting the 

 spectrum of erbium, terbium, and didymium ; and 

 he unhesitatingly decides that erbium and ter- 

 bium are distinct bodies and true elements. He 

 regards the earthy bases of these two metals as 

 protoxides, their formulae being thus, ErO and 

 TrO. Calling that of oxygen 16, the equivalents 

 of these metals are found by him as, respec- 

 tively, 95 and (nearly) 91. 



