cent. Its melting point is 112 to 113° C., and it solidifies at 93°. When
carefully prepared and purified by recrystallisation from alcohol, and
kept protected from sunlight, it can be kept for several years without
alteration.

Nitro-mannite is more dangerous than nitro-glycerine, as it is more
sensitive to shock. It is intermediate in its shattering properties
between nitro-glycerine and fulminate of mercury. It explodes by the shock
of copper on iron or copper, and even of porcelain on porcelain, provided
the latter shock be violent. Its heat of formation from its elements is
+156.1 calories. It is not manufactured upon the commercial scale.

Besides the nitro compounds already described, there are many others, but
they are of little importance, and are none of them made upon the large
scale. Among such substances are _nitro-coal_, which is made by the action
of nitric acid on coal; _nitro-colle_, a product which results from the
action of nitric acid on isinglass or gelatine, soaked in water. It is
then treated with the usual acids.

Another method is to place strong glue in cold water until it has absorbed
the maximum amount of the latter. The mixture is solidified by the
addition of nitric acid, nitrated in the usual way, and well washed.
Abel's _Glyoxiline_ is only nitrated gun-cotton impregnated with nitro-
glycerine. Nitro-lignine is only nitro-cellulose made from wood instead of
cotton; and nitro-straw is also only nitro-cellulose. The explosive known
as _Keil's Explosive_ contains nitro-glucose. Nitro-molasses, which is a
liquid product, has also been proposed, and nitro-saccharose, the product
obtained by the nitration of sugar. It is a white, sandy, explosive
substance, soluble in alcohol and ether. When made from cane sugar, it
does not crystallise; but if made from milk sugar, it does. It has been