SAFETY-LAMP. 300 



science, and the result is certainly one of the proudest 

 achievements of physico-chemical research. By merely 

 enveloping the flame of a lamp with a metallic gauze, the 

 labourer in the recesses of the gloomy mine may feel 

 himself secure from that outpouring current of inflam- 

 mable gas, which has been so often the minister of 

 death; he may walk unharmed through the explosive 

 atmosphere, and examine the intensity of its power, as 

 it is wasted in trifling efforts within the little cage he 

 carries. Accidents have been attributed to the " Davy," 

 as the lamp is called among the colliers ; but they may 

 in most cases be traced to carelessness on the part of 

 those whose duty it has been to examine the lamps, or 

 to the recklessness of the miners themselves. 



That curious metal, platinum, and also palladium, 

 possesses a property of maintaining a slow combustion, 

 which the discoverer of the safety-lamp proposed to 

 render available to a very important purpose. If we 

 take a coil of platinum wire, and, having made it red- 

 hot, plunge it into an explosive atmosphere of car- 

 buretted hydrogen and common air, it continues to 

 glow with considerable brightness, producing, by this 

 very peculiar influence, a combination of the gases, 

 which is discovered by the escape of pungent acid 

 vapours. Over the little flame of the safety -lamp, it was 

 proposed by Davy to suspend a coil of platinum whicn 

 would be thus kept constantly at a red heat. If the 

 miner became accidentally enveloped in an atmosphere 

 of fire-damp, although the flame of his lamp might be 

 extinguished, the wire would continue to glow with 

 sufficient brightness to light him from his danger, 

 through the dark winding passages which have been 

 worked in the bed of fossil fuel. This very beautiful 

 arrangement has not, however, been adopted by our 

 miners. 



It is thus that the discoveries of science, although they 

 may appear of an abstract character, constantly, sooner 



