On definite Proportions. 455 
more minutely. We have already seen that 100 parts of 
nitric acid, with 2051 of protoxide of lead, afford a neutral 
nitrate of lead. If we wish to reduce these 100 parts of 
nitric to nitrous acid, we must deprive them of + of their 
whole quantity of oxygen, including that which belongs to 
the nitrogen. If now in all nitrates the oxygen of the acid 
is six times that of the base, it must amount in 100 parts 
of the nitric acid to 6 x 14°66=88 parts. Now 8#=17°6, 
and 100 parts of nitric acid will therefore afford 100—17°6= 
824 of nitrous acid, containing 70°35 of oxygen : [or 88— 
17°6=70°4,] I must here again remark, that if the quan-\ 
tity of the oxygen of the bases has been assumed a little too 
great, the error must have a considerable effect here on ac- 
count of the multiplication by 6: this however has no effect 
on the representation here developed. If now the lead, 
which is dissolved by the solution of the nitrate, on which 
we operate, takes up the 17°6 of oxygen, the solution must 
contain a quantity of the base of which the oxygen amounts 
to 32°26, including the protoxide which was present in the 
first instance, containing 14°66. According to the analysis 
above related, the nitric acid must contain twice as much 
oxygen as this, that is, “ 64:54.” But we have seen that 
it contains in fact 5°48 more, that is, 70°35: [or rather 
5'88 more, =70°4—2 x 32°26.) If therefore this compu- 
tation is correct, a part of the nitrous acid must at the same 
time be decomposed, and consequently nitrous gas or ni- 
trogen must be disengaged. This evolution of gas, arising 
from a dissimilar decomposition of the nitric acid, is denied 
by Mr. Proust, and also by Mr, Gehlen. But may it not 
actually take place? Or rather, How could the nitrate of the 
protoxide of lead be constituted if it did not take place? 
The nitric acid would otherwise be required to saturate a 
quantity of protoxide of lead, of which the oxygen amounts 
to 4 of that of the acid, considered as having ammonium 
for its radical, or to 4, as comiposed of nitrogen and oxygen. 
This however would suppose, if my analysis of the nitrate 
of the protoxide of lead is at all correct, in the 100 parts of 
nitric acid, which saturate 205*1 of the protoxide, a quantity 
of water of which the oxygen is equal to that of the prot- 
oxide ; since 100 parts of dry nitric acid would he required 
to saturate as much of the protoxide as contains 17°59 parts 
of oxygen. But my experiments on the analysis of the ni- 
trates of the protoxide of lead and of ammonia prove incon- 
trovertibly, as it appears to me, that no such water is con- 
cealed in the acid. Consequently the conversion of the 
nitrate of the protoxide of lead into a subnitrite is not pos- 
Fra sible 
