METALLIC COMPOUNDS- 
119 
small adherent portions of the paper of the filtre, which. Theoretical 
notwithstanding all my care to prevent it, were mixed with considera- 
the powder. The saline mass, on exposure to ignition, instead tl ° n8 * 
of increasing in weight, lost from one-fourth to two-thirds in 
the hundred, which must be attributed to the volatilization of 
the stibious acid. I repeated each of these experiments several 
times, and the quantity of sublimate varied constantly between 
these limits. The stibiate of copper produced no visible 
smoke, and lost scarcely any thing by the ignition. It some- 
times happened, that the ignition was only partial, and then 
the colour was only altered in those parts which had under- 
gone ignition : but even those parts where the colour was not 
changed, appeared equally to resist the action of acids. 
These experiments prove, then, that the ignition in question 
cannot be produced by a combination with the oxigen, or with 
any other body, which did not exist in the previous combina- 
tion. But what, then, is the cause of it ? We are not as yet 
acquainted with any example where the same bodies may be 
combined in the same proportions in their different degrees of 
actual saturation : that is to say, where there are between 
these two bodies two degrees of what may be called intimacy 
of combination. Such an hypothesis would explain the pheno- 
menon of ignition, as well as the new forces of affinity might 
be supposed to have been acquired by that means. 
In this case it is necessary to imagine, that a fresh portion 
of negative electricity of one of the constituents, is combined 
with a correspondent portion of positive electricity of the other, 
and produces, by this electric discharge, the phenomenon of 
fire, while the combination, at the same time, arrives at a muck 
higher degree of eleotro-chemic indifference than before. It is 
generally known and admitted, that bodies can combine indiffe- 
rent degrees of intimacy of combination, and in different propor- 
tions : such as iron, which is combined much more intimately 
with the quantity of oxigen, which renders it oxidum ferrosum, 
than with that which converts the ferreous into the ferric 
oxide $ and we see the same difference of intimacy of combi- 
nation with different quantities of oxigen in a number of 
other combustibles ; but there is always a consideration of the 
different proportions of parts. Nevertheless, the experiments 
I have here cited, appear to indicate, that the same difference 
of 
