15® Mr. Davy on a new fulminating platinum. 
powder, when standing over mercury, occupied o.tB of a 
cubic inch. When it was transferred to pure water and agi- 
tated, it diminished to 0.15 of a cubic inch. An equal volume 
of pure nitrous gas being added to the 0.15, there was no 
sensible diminution. After the nitrous gas had been absorbed 
by a fresh solution of green sulphate of iron, the residual gas 
immediately extinguished a lighted taper. These experi- 
ments corresponded with others I had previously made, and 
they all seemed to prove that the gas produced during the 
decomposition of the fulminating powder is for the most part 
nitrogene. The appearance of gas absorbable by water, was 
at first rather unexpected. I supposed this gas might be 
ammonia, and this opinion acquired additional probability 
from calculations derived from the results of my experiments ; 
but I soon convinced myself from actual trials, that ammo- 
niacal gas is disengaged during the decomposition of fulmi- 
nating platinum by heat. 
I attempted to explode five grains of the powder in a strong 
green glass tube, two feet in length, and two-thirds of an 
inch in diameter of bore. I succeeded in exploding a suffi- 
cient quantity of the powder to furnish a half cubic inch of 
gas ; but in cooling, the tube cracked and the mercury fell. 
I immediately examined the tube. The space occupied by 
the gas was lined with a thin coat of moisture. The odour 
of ammonia was very perceptible in the tube, and turmeric 
paper was changed to brown by the moisture in it. 
The fact of the disengagement of ammoniacal gas on 
exploding the powder, seems also to be proved by a very 
simple experiment I made. I put a little of the powder in the 
centre of a tube about eighteen inches in length. I opened 
