64 Mr. Davy’s Experiments on 
oxygene is the same in all protoxides, and that the quantity 
of acid is the same in all neutral salts, i. e. that every neutral 
salt is composed of one particle of metal, one of oxygene, and 
one of acid. 
We are in possession of no accurate experiments on the 
quantity of acids required to dissolve alumine, glucine, and 
silex ; but according to Richter’s estimation of the compo- 
sition* of phosphate of alumine, alumine would appear to con- 
tain about 56 per cent, of metallic matter. 
M. Berzelius, -f in a letter which I received from him a few 
months ago, states, that in making an analysis of cast iron, he 
found that it contained the metal of silex, and that this metal 
in being oxidated took up nearly half its weight of oxygene. 
If the composition of ammonia be calculated upon, accord- 
ing to the principle above stated, it ought to consist of 53 of 
metallic matter, and about 47 £ of oxygene, which agrees 
very nearly with the quantity of hydrogene and ammonia pro- 
duced from the amalgam. 
Though the early chemists considered the earths and the 
fectly formed, (as some experiments which I have lately made, seem to shew,) there 
is probably only a single proportion of acid ; and in the super-tartrite of potash there 
is only a single quantity of oxygene, and a double quantity of acid. Whether Mr. 
Dalton’s law will apply to all eases, is a question which I shall not in this place 
attempt to discuss. 
* Thomson’s Chemistry, Vol. II. p, 581. 
f In the same communication this able chemist informed me, that he had suc- 
ceeded in decomposing the earths, by igniting them strongly with iron and charcoal. 
J I take the proportions of the volumes from the very curious paper of M. Gay 
LussAC,on the combinations of gaseous bodies, Mem. d’Arcueil, Tom. II. page 213, 
and the weights from my own estimation, according to which 100 cubic inches of 
muriatic acid gas weigh 39 grains, at the mean temperature and pressure, which is very 
nearly the same as the weight given by MM. Gay Lussac, and Thenard. 
