146 Mr. Davy on a new fulminating platinum. 
tially decomposed, and muriatic and phosphoric acids are 
probably formed. Fulminating gold is affected in a similar 
way by phosphorane. 
IV. Composition of Fulminating Platinum. 
From the manner in which fulminating platinum was ob» 
tained, it was not difficult to form conjectures concerning its 
constitution. As it was furnished by the agency of potash or 
soda on the ammonia sulphate of platinum, it was easy to 
conceive it might be composed of oxide of platinum and am- 
monia. The composition of aurum fulminans, and the ana- 
logies existing between this substance and fulminating plati- 
num, were favourable to this idea ; but the experiments I made 
afforded me more direct and satisfactory evidences on the 
subject, and confirmed the opinion I had previously formed 
of its nature. Thus, when the powder (previously well 
dried,) was put into small green glass tubes filled with dry 
mercury and exploded by heat, a quantity of gas was ob- 
tained, which had the properties of nitrogene ; moisture lined 
the sides of the tubes, and the mercury formed an amalgam 
with the platinum. 
When the powder was mixed with quicklime, and the 
mixture heated in a small retort, it was decomposed with a 
few slight cracks ; a little fluid condensed in the neck of the 
retort ; it had the smell of ammonia, and instantly rendered 
turmeric paper brown ; a little gas also came over, having the 
properties of nitrogene. The presence of moisture appeared 
to be necessary in the foregoing experiment to develope the 
ammonia ; for when the powder was mixed with quicklime, 
previously heated to redness, the slight explosions arising 
