On definite Proportions. « 275 
and the oxides of nitrogen, which contain oxygen so little 
saturated, cannot be reduced to hydrogen in common cases, 
because they give out so much oxygen, in the further sa- 
turation of which the [positive] electricity of the inflam- 
mable substances must in great measure be employed. 
Hence the nitric acid can only be restored to the state of 
nitrogen; but it may perhaps hereafter be found possible to 
reduce this substance both to hydrogen and to ammonium, 
by means of substances more powerfully [positive] than 
ammonium. In Davy’s later experiments, the electrical 
discharge seems to have produced the latter of these effects 
by the assistance of quicksilver, and the operation of potas- 
sium on ammoniacal gas the former. 
Since hydrogen always requires the same quantity of 
[positive] electricity for forming it out of the component 
parts of ammonia, whether it appears as hydrogen gas, or 
forms water with oxygen; and since this [positive] elec- 
tricity cannot be obtained without the evolution of a cor- 
responding quantity of {negative] electricity, it follows 
that ammonia must always afford hydrogen and nitrogen in 
the same proportions, whether it be decomposed by com- 
mon electricity, or by means of oxidation. On the other 
hand, in decompositions by means of potassium or in the 
circuit of the column, when ammonia is reduced in con- 
tact with quicksilver, the appearances of the decomposition 
are of a very different nature ; and the products, in com- 
parison with the quantity of ammoniacal gas employed, are 
dissimilar in quantity and kind. Now since hydrogen and 
nitrogen require for their existence a different electrical 
modification from that which originally belonged to their 
radical, they must be considered in he analyses and ex- 
eriments as simple bodies, until we shall have learned to 
express their electricities with safety by means of appro- 
priate numbers. 
Is it not however probable, according to these views, 
that sulphur may be a [negatively] electrical oxide of an 
unknown metallic base, precisely as nitrogen is an oxide 
of ammonium? I cannot undertake to answer this ques- 
tion in the negative. We have seen that sulphur, to judge 
from sulphureted hydrogen, may contain about half its 
weight of oxygen, and this proportion of oxygen agrees with 
the other degrees of oxygenation of sulphur, which may 
all be multiples of it. This must also be possible with re- 
spect to carbon, phosphorus, and arsenic. But that pure 
carbon, for instance, in plumbago, and metallic arsenic, 
which haye all the characters of the simple or supposed 
; 52 simple 
