nacious of metals. To pull asunder an iron
wire 0.787 of a line in diameter requires a weight of 549 lbs. To pull
asunder a gold wire of the same size, 150 lbs.; tin wire, 34 lbs.; gold
being thus shown to be more than four times as tenacious as tin.
(Fractions omitted.)

Malleability: Pure tin may be beaten into leaves one-fortieth of a
millimeter thick, thus requiring 1020 to make an inch in thickness.
Miller states that it can be beaten into leaves .008 of a millimeter
thick, thus requiring 3175 to make an inch in thickness. Richardson says
that ordinary tin foil is about 0.001 of an inch in thickness.

If the difficulty with which a mass of gold (the most malleable of
metals) can be hammered or rolled into a thin sheet without being torn,
be taken as one, then it will be four times as difficult to manipulate
tin into thin sheets.

Ductility: If the difficulty with which gold (the most ductile of
metals) can be drawn be taken as one, then it will be seven times as
difficult to draw tin into a wire. At a temperature of 212 deg. it has
considerable ductility, and can be drawn into wire.

Among the metals, silver is the best conductor of heat. If the
conductivity of silver be taken as 100, then the conducting power of
gold would be 53.2; tin, 14.5; gold being thus shown to be nearly four
times as good a conductor of heat as tin. Among the metals, silver is
the best conductor of electricity. If its electrical conductivity be
taken at 100, then the conducting power of gold would be 77.96; tin,
12.36; gold being thus shown to be more than six times as good a
conductor of electricity as tin.

Resistance to air: If exposed to dry, pure air, tin resists any change
for a _great_ length of time, but if exposed to air containing moisture,
carbonic acid, etc., its time resistance is reduced, although even then
it resists corrosion much better than copper or iron.

As to linear expansion, when raised from 32 deg. to 212 deg. F., aluminum
expands the most of any of the metals. Taking its expansion as 1, that
of tin would be 3, _i.e._, aluminum expands three times as much as tin.
(Dixon, "Vade Mecum.")

Solids generally expand equally in all directions, and on cooling return
to their original shape. Within certain limits, metals expand uniformly
in direct proportion to the increase in temperature, but the rate of
expansion varies with different metals; thus, under like conditions, tin
expands nearly twice (1-3/5) as much as