460 On definite Proportions. 
agreeing almost to the last places of decimals: and that the 
agreement no longer remains, if we take into account the 
oxygen of the nitrogen. In two other experiments I ob- 
ae 89°5 and 89°66 per cent. of the protoxide from this 
sait. 
We have here a new confirmation of the idea already 
suggested, that in the subnitrates, in which the acid and the 
protoxide of lead contain equal quantities of oxygen, the 
nitrogen must be considered in the computation as a simple 
substance. But when, on the other hand, the nitrous acid 
contains a quantity of oxygen which is a multiple of that 
which 1s contained in the base, the composition of the salt 
agrees only with the general Jaw on the supposition that 
oxygen is contained ip the nitrogen, Respecting the cause 
of this singular circumstance I will not hazard a conjecture. 
If we calculate the quantity of a base with which 100 
parts of nitrous acid are combined in the three salts here 
described, we find that in the subsalt they take up twice as 
much, and in the subsubsalt three times as much, of the 
protoxide, as in the neutral salt. But in the three combi- 
nations of the nitric acid such a regular progression is not 
observable, for the quantities of the base combined with 
100 parts of the acid are represented by 1, 2, and 4°75. 
This irregularity can only depend on the compound nature 
of nitrogen, and appears therefure to be an additional proof 
of that nature. 
It is easy to see, that the formation of the subsalt takes 
place at the expense of the nitrous acid. I found by an ex- 
periment, that nitrous gas was disengaged in the process, 
and in this gas I could find no perceptible trace of nitrogen, 
According to the foregoing calculations, the nitrate of the 
protoxide of lead, in being converted into subsubnitrite, 
dissolves a weight of lead nearly equal to its own, In one 
of the experiments here related, 100 parts of nitrate of lead 
had dissulved 1164 of lead; but the experiment was per- 
formed in a long-necked flask, in which a considerable por- 
tion of nitrous gas was united with the oxygen of the air 
that forced its way in, and returned into the flask in the 
form of nitric acid. This happens more particularly when 
the subsalt bas been formed, since then three parts of the 
nitrous acid must be decomposed and converted into nitrous 
gas, in order to change one part of the salt into a subsub- 
salt. This does not happen in an apparatus for distillation, 
because in this case the newly formed acid collects in the 
receiver; in which the water that is condensed is more or 
less acid, for reasons that may easily be imagined, nee 
ingly 
“ 
