used in percussion caps, being stronger and quicker than nitro-glycerine.
It is, however, very sensitive and very hygroscopic, and very prone to
decomposition. Nitro-tar, made from crude tar-oil, by nitration with
nitric acid of a specific gravity of 1.53 to 1.54. Nitro-toluol is used,
mixed with nitro-glycerine. This list, however, does not exhaust the
various substances that have been nitrated and proposed as explosives.
Even such unlikely substances as horse dung have been experimented with.
None of them are very much used, and very few of them are made upon the
manufacturing scale.




CHAPTER IV.

_DYNAMITE AND GELATINES._

Kieselguhr Dynamite--Classification of Dynamites--Properties and
Efficiency of Ordinary Dynamite--Other Forms of Dynamite--Gelatine and
Gelatine Dynamites, Suitable Gun-Cotton for, and Treatment of--Other
Materials used--Composition of Gelignite--Blasting Gelatine--Gelatine
Dynamite--Absorbing Materials--Wood Pulp--Potassium Nitrate, &c.--
Manufacture and Apparatus used, and Properties of Gelatine Dynamites--
Cordite--Composition and Manufacture.


~Dynamite.~--Dynamite consists of nitro-glycerine either absorbed by some
porous material, or mixed with some other substance or substances which
are either explosives or merely inert materials. Among the porous
substances used is kieselguhr, a silicious earth which consists chiefly of