162 
METALLIC OXIDES. 
Oxides of tin. weak an affinity to the saKne bases, that its combinations with 
them are decomposed by circumstances which do not seem to 
have any influence on the other saline combinations. We have 
seen, that the stannate of manganese ts decomposed by the 
access of air, and that the alkaline and earthy stannates are 
decomposed both by the air and by fire. 
I think, therefore, that, notwithstanding the great analogy 
which exists between the oxides of this, and those of anti- 
mony, they ought not, in preference, to be called acids, because 
their combinations, as saline bases, have a much longer duration 
than those in which they appear as an acid. But tin possesses 
the singular property of producing three salifiable oxides — that 
is, one degree of oxidation more than the nomenclature admits 
of. I take the liberty of giving the latter of these three degrees 
of oxidation the termination eum with the name of the metal $ 
I therefore call them oxidum stannosum, oxidum stannieum, 
and oxidum stanneum. Their combinations with the acids 
I shall call, for example, murias stannosus, murias stannicus, 
and murias stanneus. It is evident, that the nomenclature 
allows of their combinations with the saline bases, being called 
stannates and stannites, without its being necessary to give the 
name of acid to these oxides in their isolated state. 
The Combinations of Tin with Sulphur. 
Various chemists have employed themselves in examining 
the sulphurets of tin, and their results have been frequently very 
different j the reason is, that tin requires, in order to unite 
with sulphur, a temperature sufficiently high to volatilize the 
greatest part of the sulphur before the combination takes place, 
and consequently there remains, at that moment, too small a 
quantity to saturate the metal. On analysing the imperfect 
combination, the results were, as may be supposed, very vari- 
able. It appeared, that the same thing took place with the sul- 
phurets of other metals. The celebrated Vauquelin has published 
a table of the composition of sulphurets, which too clearly proves 
the truth of what I have said. 
I have already mentioned, that I had prepared a saturated sul- 
phuret of tin, on remelting the pulverized sulphuret, and care- 
fully mixing it with pulverized sulphur, itformed, on thisoccasion, 
first, 
