night, during the first three or four days, afterwards three or four times
a day. In all fourteen days are occupied in the nitration process. It is
then strained through an earthenware strainer, washed with warm water,
drained, and dried. For the purpose of producing this material in a
granulated condition, which is found more convenient for drying, and
further nitrification, it is placed in a tub, and live steam passed
through, until brought up to the boiling point (the tub should be about
half full), cold water is then run in whilst violently agitating the
contents until the naphthalene solidifies; it can then be easily drained
and dried. For the further treatment to make di-nitro-naphthalene, 18
parts of nitro-naphthalene are placed in an earthenware pan, together with
39 parts of sulphuric acid of 66 deg. B., then 15 parts of nitric acid of 40 deg.
B. are added, in small quantities at a time, stirring the mixture
continually. This adding of nitric acid is controlled by the fuming, which
should be kept down as much as possible. The operation takes ten to twelve
days, when 100 times the above quantities, taken in kilogrammes, are
taken. At the end of the nitration the di-nitro-naphthalene is removed to
earthenware strainers, allowed to drain, washed with hot water and soda
until all acid is removed, washed with water and dried. The di-nitro-
naphthalene gives some trouble in washing, as some acid is held in the
crystals which is liable to make its appearance when crushed. To avoid
this it should be ground and washed with carbonate of soda before drying;
an excess of carbonate of soda should not, however, be used.

~Electronite.~--This is a high explosive designed to afford safety in coal
getting. This important end has been attained by using such ingredients,
and so proportioning them, as will ensure on detonation a degree of heat
insufficient under the conditions of a "blown-out" shot, to ignite fire
damp or coal dust. It is of the nitrate of ammonium class of permitted
explosives. It contains about 75 per cent. of nitrate of ammonium, with
the addition of nitrate of barium, wood meal, and starch. The gases
resulting from detonation are chiefly water in the gaseous form, nitrogen,
and a little carbon dioxide. It is granulated with the object of
preventing missfires from ramming, to which nitrate of ammonium explosives
are somewhat susceptible. This explosive underwent some exhaustive
experiments at the experimental st