14Q Mr. Davy on a new fulminating platinum. 
quantity of fixed alkali employed is smaller or greater, and 
the process of boiling continued for a shorter or longer time. 
If, after the addition of the fixed alkali the fluid be boiled 
down to dryness, the fulminating powder will be of a dark 
colour, and if the heat be still continued, it will be partially 
decomposed, and this effect will be accompanied with slight 
explosions. The differences of colour observed in the fulmi- 
nating powder are not perhaps connected with any difference 
in its constitution ; at least this variety of circumstance does 
not appear to deteriorate its fulminating properties in any 
sensible degree, except in cases where the process has been 
carried too far in the use of the fixed alkali, aided by long 
continued heat. 
When the fulminating powder in small quantity is placed 
on bibulous or filtering paper, and gradually heated over a 
clear fire, or an Argand lamp, it explodes with a loud report, 
the paper is lacerated, and its parts violently rent asunder. 
A bit of the powder no bigger than the head of a pin, or 
about ~ of a grain, produces a sharp crack, and makes a 
hole in the paper. 
One grain of the powder was placed on a slip of thin sheet 
copper, and exploded by the heat of a taper : it produced a 
report louder than the discharge of a pistol, and the copper 
was deeply indented, as if it had received the impression of a 
large punch. 
A - of a grain of the powder was exploded on a slip of 
tinned iron: the lustre of its surface was tarnished, and it had 
the appearance of an alloy of platinum and tin. The same 
quantity of the powder was placed between two slips of 
Altering paper and exploded; both slips were perforated and 
