combinations of Oxy muriatic Gas and Oxygene , &c. 17 
respecting the peroxide confirm this idea. Potassium, per- 
fectly saturated with oxygene, would probably contain six 
sulphuretted hydrogene, from its electrical decomposition. As hydrogene is the sub*., 
stance which combines with other bodies in the smallest quantity, it is perhaps the 
most fitted to be represented by unity ; and on this idea the proportions in ammonia 
will' be 3 of hydrogene to i of nitrogene, and the number representing the smallest 
proportion in which nitrogene is known to combine will be 1 3.4. Mr. Dalton, New 
System of Chemical Philosophy, pages 323 and 436, has adopted 4.7 or 5.1, as the 
number representing the weight of the atom of nitrogene ; and has quoted my experi- 
ments, Researches, Chemical and Philosophical, as authorising these numbers ; but all 
the enquiries on nitric acid, nitrous gas, nitrous oxide, and on the decomposition of 
nitrat of ammonia stated in that work, conform much more nearly to the number 13.4. 
According to Mr. Dalton, nitrat of ammonia contains one proportion of acid and 
one of alkali, and nitrate of potash two proportions of acid and one of alkali ; but it 
is easy to see that the reverse must be the case. Nitrate of ammonia is known 
to be an acid salt ; and nitrate of potash a neutral salt ; which harmonizes with the 
views above stated. Mr. Dalton estimates the quantity of water in nitric acid of 
specific gravity 1.54, at 27.5 per cent.; and this, according to him, is a stronger acid 
than he obtained by decomposing fused nitre by sulphuric acid, which contained only 
19 per cent, of water, and one quantity of sulphuric acid, according to him, will pro- 
duce from nitre, more than an equal weight of nitric acid, and he supposes no water 
in nitre ; so that his conclusion as to the quantity of water in liquid nitric acid on his 
own data must be incorrect, I find water in fused nitre, by decomposing it by boracic 
acid. 
I shall enter no further at present into an examination of the opinions, results, and 
conclusions of my learned friend ; I am however obliged to dissent from most of them, 
and to protest against the interpretations that he has been pleased to make of mv ex- 
periments ; and I trust - to his judgment and candour for a correction of his views. 
I I is impossible not to admire the ingenuity and talent with which Mr. Dalton has 
arranged, combined, weighed, measured, and figured his atoms ; but it is not, I con- 
ceive, on any speculations upon the ultimate particles of natter, that the true theory of 
definite proportions must ultimately rest. It has a surer basis in the mutual decom- 
position of the neutral salts, observed by Richtfr and Guyton de Morveau, in 
the mutual decompositions of the compounds of hydrogene and nitrogene, of nitrogene 
and oxygene, of water and the oxymuriatic compounds ; in the multiples of oxygene 
in the nitrous compounds ; and those of acids in salts, observed by Drs. Wollaston 
MDCCCXI. D 
