90

detonated in a tube of about two-fifths ofan inch in diameter, displaced a quantityof water which demonstrated an expansionof fifteen times their original bulk. Thiswould indicate a temperature of above 5000°of Fahrenheit, and the real temperature isprobably much higher; for heat must belost by communication to the tube and thewater. The heat of the gaseous carbon incombustion in this gas, appears more in-tense than that of hydrogene; for I found thata filament of platinum was fused by a flameof cyanogen in the air which was not fusedby a similar flame of hydrogene.

4. Some general observations, and practical inferences.

The knowledge of the cooling power ofelastic media in preventing the explosion ofthe fire-damp, led me to those practical re-searches which terminated in the discoveryof the wire-gauze safe-lamp; and the ge-neral investigation of the relation and ex-tent of these powers, serves to elucidate theoperation of wire-gauze and other tissuesor systems of apertures permeable to lightand air, in intercepting flame, and confirms