448 P>' f- Berzelitis on Selenium and Lithicni. [June 



But, although my vanity might have caused me to wish to con- 

 sider it as a simple non-metallic substance, as the number of 

 these bodies is so limited, and the discovery of an additional 

 one must, therefore, be the more interesting ; yet, in spite of 

 this circumstance, I believe it must be regarded as a metal. 

 Every thing depends upon what is meant by a metal. If you 

 compare them with the simple non-metallic substances, there is 

 only one character which distinguishes them, their brilliant 

 metallic lustre ; for the property of conducting electricity is also 

 found in charcoal without one, on this account, considering it 

 as a metal. Now selenium possesses this brilliant metallic 

 lustre in a veiy remarkable degree. When it is cooled rapidly, 

 it has a vitreous fracture, but one that is entirely metallic ; and 

 it possesses a certain, although scarcely perceptible transparency. 

 If, on the contraiy, we permit it to become solid gradually, it 

 has a granulated fracture, and is extremely like a piece of 

 cobalt. The slip of green paper, which accompanies this letter, 

 is coated with selenium ; I formed it into a pellicule, by reduc- 

 ing it from the selenic acid dissolved in water by sulphureous 

 acid gas. The pellicule is formed on the surface of the fluid, 

 and assumes completely the aspect of a film of gold. Now as 

 selenium must belong to one of these classes, and as there are 

 characters which are common to both of them, I thought it 

 proper to place it in that of which it possesses the most marked 

 character. I divide metals into two classes, those that are" 

 capable of forming acids, and those that act as bases ; and I 



place selenium among the acidifiable metals near arsenic 



Arfvedson has proved that spodumene contains eight per 

 cent, of lithion ; * he has also found four per cent, of it in 

 another mineral from Uton, which is called crystallized lepido- 



lite ; it contains also boracic acid, silex, and alumine 



Lithion contains 43*9 per cent of oxygen.f With respect 



to selenium, I must inform you that I have found a fossil which 



* In the number of the Annates de Chimie for March, wc have the following 

 letter froinM. Gillet de Laumont to the editors. 



M. Swedenstierna informed me by a letter of March 17, that M. Arfved^n had 

 not entirely completed his analysis of petalite when he announced that he had ob- 

 tained three per cent, of lithion, and that he now believes he has found Jive per cent. 

 in it ; this would bring his analysis more near to that of M. Vauquelin's, who has 

 actually found seven per cent, in some very pure pieces which I sent him. M. Swe- 

 diensterna remarks also that M. Arfvedson has just discovered eight per cent, of 

 lithion in triphane (spodumene") undoubtedly from Uton. In consequence of this 

 important discovery, which will probably be extended to other mineral substances, 

 chemists will be able to procure this new alkali very easily, triphane being less 

 rare than petalite; M. Lennhard has just discovered triphane in the Tyrol, and 

 M. Hesinger conceived that he had obtained six per cent, of potash from it, but 

 this will probably prove to be lithion. 



t M. Vauquelin concludes from his experiments, that 100 parts of lithion con- 

 tain 43*5 of oxygen, a quantiiy which he observes is greater than that of all the other 

 alkalies. The editors of the Annales de Chimie remark, that according to this 

 estimate the equivalent number of the metal is 12*97, of its oxide '2*2'97, of its dry 

 sulphate 72-97, aud of its crystallized sulphate 8^-97. — Ann. de Chim. March, -^88. 



