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CHAPTER VI. 



DYNAMITES. 1 



1. DYNAMITES IN GENEKAL. 



1. IN 1866, iii consequence of terrible accidents caused by 

 explosions, 2 the use of this substance was going to be forbidden 

 everywhere, when a Swede, Mr. Nobel, conceived the idea of 

 rendering it less sensitive to shocks by mixing it with an inert 

 substance, a well-known artifice for attenuating the effects of 

 the ordinary powder, but which leads to unexpected results in 

 the present case. Nobel added to it first a little methylic 

 alcohol ; then, this expedient being insufficient, he mixed it 

 with amorphous silica. He designated this mixture by the 

 name of dynamite. 



He soon recognized, and this was a very important discovery, 

 that the explosion requires the use of special mercury fulminate 

 detonators, and that it acquires in this way an exceptional 

 violence ; it can then be produced even under water. By using 

 these detonators tamping may be dispensed with, when 

 absolutely necessary, in blasting with dynamite. 



This name has since been extended to very diversified 

 mixtures, with nitroglycerin as base, and at the present day a 

 score of different dynamites are distinguished. Mixtures con- 

 taining liquid explosives other than nitroglycerin have even 

 been designated by the same word. Dynamites have the 

 common property of not exploding either by simple inflamma- 

 tion, slight shock, or moderate friction. But they explode, on 

 the contrary, by the use of strong caps, called detonators, gene- 

 rally composed of mercury fulminate. 



Dynamites are divided into several classes. 



2. In some, containing an inert base, the nitroglycerin is 



1 See " La Nitroglycerine et les Dynamites," par Fritsch, 1872 (" Memorial 

 de Tofficier du Genie ") ; " Manuel de pyrotechnic a 1'usage de I'ArtilJerie de 

 Marine," torn. ii. ; " Traits' de la poudre," etc., revu par Desortiaux, p. 798. 

 1878. 



2 Stockholm, Hamburg, Aspinwall, San Francisco, Quenast in Belgium. 



