T. N. T. These disadvantages in picric acid led to its being largely replaced by tri-nitro toluol, or T. N. T., which has a bursting pressure of 119,000 pounds per square inch as against 135,820 pounds for picric acid. Yet the advantages of the former more than compensate and warrant its use being preferred. T. N. T. does not act on metals to create sensitive salts and is, therefore, perfectly stable. The French name for T. N. T. is “Tolitype,” the Spanish “Trilite,” and the German “Trotyle.” It is produced by heating troulue with a mixture of nitric acid and sulphuric acid.
Troulue. Troulue is a liquid hydro-carbon obtained along with benzine.
Tetryl. Tetryl is another coal tar product containing more nitrogen than lyddite, and is employed in detonators with a little lead azide, making a less sensitive and safer preparation than fulminate of mercury.
Aunnonal. Aunnonal is a mixture of T. N. T., aluminum in fine powder and nitrate of ammonia, and a trace of charcoal. It is safe and powerful, but has the disadvantage of attracting moisture, and for that reason does not always explode.
Dynamite. Dynamite is the most generally used of any blasting material in the world. It was invented in 1866 by Alfred Nobel. Its principal consisted in using an absorbent commonly called a “dope,” which would take up the nitro-glycerine and hold it after the manner of a sponge.
A suitable dope should possess a cellular structure so that the nitro-glycerine may be subdivided into minute globules, each being held separately in its own cell, completely isolated from every other. In this condition its sensitiveness is greatly reduced, depending, of course, on the amount of nitro-glycerine absorbed. Dynamite may be classified, according to the nature of the absorbent used, as follows:—
1. Dynamites with inert base,
(Kieselguhr, Magnesium carbonate.)
2. Dynamite with an active base,