Mr, Davy’s Researches on the 
236 
sation of from t t - to - T - of the volume; but the gas remaining 
was muriatic acid gas. I have attempted to make the expe- 
riment in a manner still more refined, by drying the oxy muriatic 
acid and the hydrogene by introducing them into vessels con- 
taining muriate of lime, and by suffering them to combine at 
common temperatures; but I have never been able to avoid a 
slight condensation ; though in proportion as the gasses were 
free from oxygene or water, this condensation diminished. 
I mixed together sulphuretted hydrogene in a high degree 
of purity and oxymuriatic acid gas both dried, in equal volumes : 
in this instance the condensation was not ^ ; sulphur, which 
seemed to contain a little oxymuriatic acid, was formed on the 
sides of the vessel ; no vapour was deposited ; and the residual 
gas contained about of muriatic acid gas, and the remainder 
was inflammable. 
M. M. Gay Lussac and Thenard have proved by a copious 
collection of instances, that in the usual cases where oxygene is 
procured from oxymuriatic acid, water is always present, and 
muriatic acid gas is formed ; now, as it is shewn that oxy- 
muriatic acid gas is converted into muriatic acid gas, by com- 
bining with hydrogene, it is scarcely possible to avoid the 
conclusion, that the oxygene is derived from the decomposition 
of water, and, consequently, that the idea of the existence of 
water in muriatic acid gas, is hypothetical, depending upon an 
assumption which has not yet been proved— the existence of 
oxygene in oxymuriatic acid gas. 
M. M. Gay Lussac and Thenard indeed have stated an 
experiment, which they consider as proving that muriatic acid 
gas contains one quarter of its weight of combined water. 
They passed this gas over litharge, and obtained so much 
water ; but it is obvious that in this case they formed the same 
