242 METALLIC OXIDES. 



larger quantities, a piece of antimony, fused in a tube of glass, 

 to give it a convenient form, was employed as the positive con- 

 Also by volta- doctor in the decomposition of pure water by a voltaic pile of 

 fifty pair. The antunony produced oxigen gns in extremely 

 small bubbles, but, at the same time, it became covered with 

 a grey pellicle which became almost black when the metal was 

 - dried in the air. That part of the antimony which was covered 

 by the cork had preserved its metallic brilliancy, and the diffe- 

 rence between the suboxided surface and clear metal, -was very 

 marked. But as even in this experiment the suboxide did not 

 -appear visibly to increase as soon as the pellicle was formed, 

 1 employed antimony reduced to powder as the positive con- 

 ductor, and touched at the bottom by the point of the platina 

 Another vol- wire. This point produced oxigen gas, which, from time to 

 onthe antim. ^ ime > rose through the powder, and this last began to be covered 

 powder. with a lighter and bluish powder. After some days this pow- 



der had increased so much as to be capable of. being separated 

 from the metal by means of levigation. This becomes nearly 

 black by drying, and, when rubbed with a polished bloodstone, 

 Dccompos. did not give the smallest trace of metallic brilliancy. When 

 ide bv an acid" lnrown mt0 muriatic acid, this fluid emitted a slight smell of 

 hydrogen, and a few instants afterwards, metallic particles were 

 seen swimming in the acid, and were more easily precipitated 

 by soda than the powder before the action of the acid. The 

 suboxide of antimony, therefore, possesses a property common 

 to most of the suboxides, of being decomposed by the action 

 of acids, by concentrating the oxigen upon part of the me- 

 tal to produce a base combinable with the acid, and reducing 

 the other part to the metallic state. 

 Composition I have not been able to produce this suboxide in a sufficient 

 ■J*, dcteomij- q Uari tity to analyse it 3 but I shall hereafter shew how it is pos- 

 sible to find its composition by calculation with some degree 

 of probability .- 

 2. Oxidum 2 - Oxidum stibiosum. The characters of this are very well 



stibiosimi. known from the experiments of Proust and Thenard. It has a 

 fusible &c. & r fy wmte colour, is slightly soluble in water, is easily fused by 

 a cherry red heat into a yellowish fluid. The mass, when 

 cold, is crystallized in the manner of asbestos, but the groups 

 of crystals cross in every direction, and it is not difficult to 

 break their continuity. 



a. In 



