Sir Humphry Davy's account , &c. 
When the thickest wires are used in the gauze, it becomes 
strongly red hot, particularly at the top, but yet no explosion 
takes place. The flame is brighter the larger the apertures 
of the gauze ; and the cylinder of 62,5 apertures to the square 
inch, gives a most brilliant light in a mixture of one part 
of gas from the distillation of coal, and 7 parts of air ; the 
lower part of the flame is green, the middle purple, and the 
upper part blue. 
I have tried cylinders of 6400 apertures to the square inch, 
in mixtures of oxygene and carburetted hydrogene, and even 
in mixtures of oxygene and hydrogene; and though the wire 
became intensely red hot, yet explosions never took place : 
the combustion was entirely limited to the interior of the lamp. 
In all these experiments there was a noise like that pro- 
duced by the burning of hydrogene gas in open tubes 
These extraordinary and unexpected results lead to many 
enquiries respecting the nature and communication of flame ; 
but my object, at present, is only to point out their application 
to the use of the collier. 
All that he requires to ensure security, are small wire 
cages* to surround his candle or his lamp, which may be 
made for a few pence, and of which various modifications 
may be adopted ; and the application of this discovery will 
not only preserve him from the fire-damp, but enable him to 
apply it to use, and to destroy it at the same time that it gives 
him an useful light. 
* Fig. II. PI. 1. represents this contrivance. 
