viz. the invention of the SAFETY-LAMP for coal mines, which has been
generally and successfully adopted throughout Europe. This invention has
been the means of preserving many valuable lives, and preventing horrible
mutilations, more terrible even than death; and were this Sir Humphry
Davy's only invention, it would secure him an immortality in the annals
of civilization and science. The general principle of this discovery may
be described as follows:

"The frequency of accidents, arising from the explosion of the fire-damp,
or inflammable gas of the coal mines, mixed with atmospherical air,
occasioned the formation of a committee at Sunderland, for the purpose of
investigating the causes of these calamities, and of endeavouring to
discover and apply a preventive. Sir Humphry received an invitation, in
1815, from Dr. Gray, one of the members of the committee; in consequence
of which he went to the North of England, and visiting some of the
principal collieries in the neighbourhood of Newcastle, soon convinced
himself that no improvement could be made in the mode of ventilation, but
that the desired preventive must be sought in a new method of lighting
the mines, free from danger, and which, by indicating the state of the
air in the part of the mine where inflammable air was disengaged, so as
to render the atmosphere explosive, should oblige the miners to retire
till the workings were properly cleared. The common means then employed
for lighting the dangerous part of the mines consisted of a steel wheel
revolving in contact with flint, and affording a succession of sparks:
but this apparatus always required a person to work it, and was not
entirely free from danger. The fire-damp was known to be light
carburetted hydrogen gas; but its relations to combustion had not been
examined. It is chiefly produced from what are called blowers or fissures
in the broken strata, near dykes. Sir Humphry made various experiments on
its combustibility and explosive nature; and discovered, that the