Notices, 
483 
tiere discussed : certain it is, that we find it abundantly diffused 
through the atmosphere, and on the surface of the earth, and bn ^ 
various bodies attached to the earth : wc know also that some 
kinds of bodies will convey this fluid with greater facility than 
others will. Such bodies as most readily convey it from object to 
object, are called conductors: the most ^common of which are all 
metals, in the following order of perfection ; gold, silver, platina, 
brass, iron, tin, and lead; metallic ores, the fluids of animal bodies, 
water, ice, snow, green wood, and most earthy substances. There 
are other bodies which will not, without difficulty, conduct it ; and 
which, on that account, are called non-conductors : such are glass, 
sulphur, resin, silk, cotton, feathers, wool, hair, paper, ashes, and 
most hard stones. 
From hence it may be inferred that, in dangerous thunder wea- 
ther, we should carefully avoid standing or sitting in contact with 
any of the conductors. 
By dangerous thunder weather, I mean such Storms as are over 
our heads or near to us. The distances of which may be nearly 
ascertained, by the known progress of sound through the air, 
which is at the rate of about 381 yards in a second of time ; so that 
if there are nine beats of a clock, or ten of the pulse of a person 
in health, between a flash of lightning and the report of thunder, 
the distance is then about two miles, and no danger is at hand ; but 
if no more than about four beats of a clock, or five pulsations, are 
between them, danger may be apprehended, and precaution should 
be taken. 
In the open air, standing under tall trees, especially such as 
have dead or dry branches, or against very lofty buildings, is dan- 
gerous. 
As lightning runs swiftly along, or plays amongst metallic bodies, 
let care be taken to avoid all such, whether out of doors or within. 
All doors and windows of apartments should be set open, that 
lightning may have free passage through. 
A sitting or recumbent posture on chairs, mattresses, couches, 
or beds, filled with hair, wool, or feathers, in such part of a room 
as may be out of the influence of conductors, or may not be in the 
way of any current between windows and doors, is, undoubtedly, 
the safest situation that can be chosen. 
The furniture of the fire-place should be carefully avoided. 
So, also, should the wires and cords of bells. 
Picture-frames, and other furniture gilt, are unsafe to stand 
close by. A most remarkable effect of lightning, in gilded rooms 
happened in the hotel occupied by Lord Tilney, at Naples, in the 
