Intelligence and Miscellaneous Articles. 179 



body with absolute success ; and though but a very trifling applica- 

 tion of natural philosophy to the practice of surgery, I have no doubt 

 that, had it been adopted before, many joints would have been saved ; 

 and I confidently anticipate that it will be the means, in future, of 

 frequently saving these parts from destruction." — Lecture on the De^ 

 tection of Needles and other Steel Instruments. 



ON TWO NEW METALS, PELOPIUM AND NIOBIUM, DISCOVERED 

 IN THE BAVARIAN TANTALITES. BY PROF. H. ROSE. 



I have discovered in the tantalite of Bavaria two new metals, in 

 the present memoir however I shall only treat of one : the oxide 

 of the second metal, to which I have for the present assigned the 

 name of oxide ofpelopium, greatly resembles tantalic acid, although 

 I am fully persuaded that it is distinct. I shall however institute 

 a series of experiments to determine their precise difference. 



For more than four years I have been engaged in investigating 

 the tantalites from various localities, and the tantalic acids derived 

 from them. An observation of my brother engaged me to under- 

 take these researches. He found that the tantalites of Bodenmais 

 in Bavaria, and those of North America, have the same crystalline 

 form as Wolfram. I had also noticed that the tantalites from the 

 same or from different localities, having the same form of crystal 

 and the same chemical composition, differed from each other by 

 their specific gravity. 



The analysis of these different tantalites was executed according 

 to Berzelius's method, by fusing the mineral reduced to a very fine 

 powder with bisulphate of potash in a platinum crucible. 



To obtain an accurate idea of the composition of the tantalites of 

 Bavaria and of North America, it was requisite to submit the tan- 

 talic acid obtained from them to a very strict examination. On 

 comparing the amount of oxygen of the tantalic acid, derived from 

 these localities, with the amount of oxygen of the bases, protoxide 

 of iron and protoxide of manganese, the relation existing between 

 them is found to be not simple. This relation is, on the other hand, 

 perfectly simple in the tantalites from Finland, viz. as 3 : 1. The 

 tantalic acid derived from the tantalites of Finland only is pure, its 

 characters have been described by Berzelius, and it alone will 

 retain the name of tantalic acid. The acid obtained from the 

 tantalites of Bavaria is composed of two acids, one of which greatly 

 resembles the tantalic acid procured from the Finland tantalites, and 

 will form the subject of a future communication. The other like- 

 wise resembles tantalic acid, but differs from it in many essential 

 points : it is the oxide of a metal which differs from all known 

 metals. I have called it Niobium, and its acid niobic acid, from 

 Niobe, daughter of Tantalus, a name which calls to mind the resem- 

 blance between the two metals and their oxides. 



Tantalic and niobic acids bear most resemblance in their properties 

 to titanic acid and the blnoxide of tin : all four have probably the 

 same composition. Both of them, when calcined in the hydrated 

 state, present the same luminous phaenomenon. Both are white be- 



