4 6 
METALLIC COMPOUNDS, 
8. A particular phenomenon produced by some of the stibiates 
and stibiites. 
Remarkable Before we quit the oxides of this metal, I shall mention a 
som^orthlT phenomenon which several of the stibiates and stibiites 
compounds, possess j and of which the explanation throws very great light 
upon the theory of chemistry. 
If in a small crucible, or spoon of platina, the stibiate or 
stibiite of cobalt, copper, or zinc, first deprived of their water of 
combination be heated before the blow pipe at a certain 
temperature, it takes fire and burns for a few moments with an 
extremely vivid ignition. After cooling, the mass is found to 
have undergone a very remarkable change. The stibiate of 
cobalt becomes of a pale red, or rather a brick colour $ and the 
stibiates of copper and of zinc are both white. 
As the two metals which are in these salts, have been carried 
to the highest degree of oxidation, this phenomenon cannot be 
explained by an ulterior oxidation. The stibiates which, before 
this operation, were very easily decomposed by stronger acids, 
now resist their action. The most concentrated muriatic acid, 
no longer decomposes them, and if it dissolves a small quantity, 
it takes up the acid and the base alike. Nevertheless, after 
continued digestion for several weeks, it appeared to me, that 
these substances had undergone a partial decomposition, though 
not to be compared with that, which, before the ignition would 
have taken place at the first instant of contact with the acid. 
The concentrated muriatic acid, does not develope the slightest 
trace of oxymuriatic gas, which proves that the metals are not 
in an higher degree of oxidation. I have not observed any 
similar effect in heating the stibiates of potash or of the earths, 
neither has this ignition appeared in the stibiates of lead and 
manganese, though by the action of fire they became insoluble 
in acids, and the stibiate of manganese resumed its ordinary 
white colour 
If either antimony in powder, or the stibious acid be mixed 
with the red oxide of mercury, and exposed to the fire, the 
antimony produces a detonation accompanied with vivid ignition, 
metallic mercury rises in vapour, and there remains a very 
voluminous powder of a deep olive colour. I at first supposed 
that this powder, which had undergone strong ignition, and 
consequently 
