9i 
on the Nature of certain Bodies . 
gas was evolved, and a dark gray mass was produced, which 
acted upon water with much effervescence, but left no solid 
inflammable residuum. 
8. Analytical Experiments on Muriatic Acid. 
I have made a greater number of experiments upon this 
substance, than upon any of the other subjects of researcli 
that have been mentioned ; it will be impossible to give any 
more than a general view of them within the limits of the 
Bakerian lecture. 
Researches carried on some years ago, and which are 
detailed in the Journals of the Royal Institution, shewed that 
there were little hopes of decomposing muriatic acid, in its 
common form, by Voltaic electricity. When aqueous solution 
of muriatic acid is acted upon, the water alone is decomposed ; 
and the Voltaic electrization of the gas affords no indica- 
tions of its decomposition ; and merely seems to shew, that 
this elastic fluid contains much more water than has been 
usually suspected. 
I have already laid before the Society, an account of some 
experiments made on the action of potassium on muriatic acid. 
I have since carried on the same processes on a larger scale, 
but with precisely similar results. 
When potassium is introduced into muriatic acid gas, pro- 
cured from muriate of ammonia and concentrated sulphuric 
acid, and freed from as much moisture as muriate of lime is 
capable of attracting from it, it immediately becomes covered 
with a white crust, it heats spontaneously, and by the assistance 
of a lamp, acquires in some parts the temperature of ignition, 
but does not inflame. When the potassium and the gas are in 
Ns 
