$8 Mr. Davy's Lecture on some new analytical Researches 
the operation. A solid mass remained of a greenish colour at 
the surface, but dark gray in the interior. It was extremely 
inflammable, and often burnt spontaneously when exposed to 
air ; when thrown upon water, it produced a violent explo- 
sion, with a smell like that of phosphuretted hydrogene. In 
the residuum of its combustion there was found muriate of 
potash, and phosphate of potash. 
I endeavoured to perform this experiment in an iron tube, 
hoping that if the muriatic acid was decomposed in the pro- 
cess, its inflammable element, potassium and phosphorus, 
might be separated from each other by a high degree of heat; 
but in the first part of the operation the action was so intense, 
as to produce a destruction of the apparatus, and the stop-cock 
was separated from the tube with a loud detonation. 
I heated potassium in the vapour of the compound of muria- 
tic and phosphoric acid ; but in this case, the inflammation 
was still more intense, and in all the experiments that I have 
hitherto tried, the glass vessels have been either fused or 
broken ; the solid residuum has however appeared to be of the 
same kind as that I have just described. 
The results of the operation of the sulphuretted compounds 
containing muriatic acid free from water upon potassium, are 
still more extraordinary than those of the phosphuretted com- 
pounds. 
When a piece of potassium is introduced into the substance 
that distils over during the action of heated sulphur upon 
oxymuriatic acid, it at first produces a slight effervescence, and 
if the volume of the potassium considerably exceeds that of 
the liquid, it soon explodes with a violent report, and a most 
intense light. 
