14s Mr. Davy on a new fulminating platinum-. 
have occasion to notice other points of resemblance in their 
properties. 
The temperature at which fulminating platinum explodes, 
appears to be about 400° Fahrenheit. When it was placed 
on a surface of mercury heated to 420°, it instantly exploded. 
When the thermometer stood at 41 o°, a short interval elapsed 
before this effect took place. In two instances I succeeded 
in exploding it at 400°. From some comparative trials, I 
found fulminating gold exploded in similar circumstances, 
but I could not succeed with it at a temperature below 406°. 
I am inclined to think, both fulminating powders, if dried at 
the same temperature, will be found to explode nearly at the 
same degree of heat. Under certain circumstances, both of 
the fulminating compounds appear to lose their explosive 
property, and to be quietly decomposed. This was observed, 
in some instances, when they were placed on mercury at a 
temperature varying from 300° to 380°, and a very short 
interval suffered to elapse before the heat was raised. It 
was not possible, then, to explode them at any temperature. 
In other cases, however, in which there was a similarity of 
circumstances, both powders exploded. These results, though 
apparently capricious, or even opposite, may perhaps admit 
of some explanation. The mercury on which the experi- 
ments were tried was impure, and exhibited by heat a tar- 
nished surface, from partial oxidation. Hence, in the fore- 
going experiments, the fulminating powders exploded in 
some cases, as when placed on an oxidated surface, because 
the heat did not call into play any other affinities than those 
existing between the elements of the compounds. But the 
powder did not explode in other instances ; as when in contact 
