I 4 , 4 > ® r ' Henry on the aeriform compounds 
shank.* He observed that a mixture of chlorine with hy- 
drogen, carburetted hydrogen, or carbonic oxide in certain 
proportions, kept in a bottle entirely filled with the mixture, 
and furnished with an air-tight stopper, did not exhibit any 
immediate action, but that in twenty-four hours, on with- 
drawing the stopper, the fluid immediately rushed in, and 
filled most of the space originally occupied by the gases. 
But he was not aware of the influence of light on these 
changes, which was discovered about the same time by Gay 
LussAcf and by Dalton. J It does not, however, appear to 
have been ascertained by either of them, whether the com- 
plete exclusion of light prevents any degree of action of 
chlorine and carburetted hydrogen on each other. I mixed, 
therefore, those two gases in different proportions in well 
stopped vials, which were completely filled with the mixture, 
and covered by opake cases. When the stoppers were 
removed under water, at various intervals after the mixture, 
from a few minutes to 39 days, no diminution whatever of 
volume was found to have taken place ; and after having 
removed the chlorine by liquid potash, the carburetted hy- 
drogen gas gave the usual products of carbonic acid, and 
consumed the usual proportion of oxygen. Mixtures also 
of hydrogen and chlorine, and of carburetted hydrogen and 
chlorine, standing over water in graduated tubes, which were 
shaded by opake covers, sustained no loss of bulk, except 
what arose from the absorption of chlorine by the water, 
the combustible gas remaining wholly unaltered. It may be 
* Nicholson’s Journal, 4to. V. 202. 
f Mem. de la Soc. d’Arcueil. II. 349. 
J New System of Chemical Philosophy, p. 300. 
