536 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



easily inflamed by a shock. Where this takes place readily, 

 the effect of the percussion is transmitted immediately through 

 the whole mass. This is the case with quartzy sands. When- 

 ever the dynamite is prepared with plastic matter, ochre, etc., 

 only part of the mass detonates, the rest acting by simple ex- 

 plosion. 18 A, May 9, 1873, 192. 



NEW FOEM OF EXPLOSIVES. 



Sir Charles W.Vincent makes a communication to Iron in 

 reference to new explosives, the object being especially to call 

 attention to a recent patent by Dr. Sprengel. The theory 

 of explosions is based upon the rapid disengagement of an 

 enormous volume of gas in a confined space ; this being pro- 

 duced in such quantity as by its expansive pressure to ac- 

 complish the object of riving and bursting asunder the in- 

 closure. As a general rule, these explosives, like fire and 

 water, are very good servants, but very bad masters, and their 

 tendency to go off" when their services in this direction are 

 not needed is the frequent cause of a great amount of mis- 

 chief both to life and property. The object of Dr. Sprengel 

 has been to devise some method by which the components 

 of the explosive may be kept apart until the moment when 

 needed for use, so that if either be subjected to the action of 

 heat or percussion, no damage will be the result. The one 

 beins: a combustible and the other an oxidizinix aixent, nei- 

 ther will act injuriously unless in combination with the other. 

 These combustible and oxidizino- aorents, accordincr to Dr. 

 Sprengel, should be from different states of matter : thus, if 

 the one be a solid, the other must be a liquid, and he proposes 

 to place the solid but finely divided oxidizing substance in a 

 vessel or chamber, and to add to it Avhen needed for use the 

 liquid combustible, and explode the two by means of a det- 

 onating fuse or percussion cap. The fluid oxidizing agent 

 preferred by him is nitric acid, while the solid combustible will 

 consist of such nitro-compounds as are not explosive, such as 

 nitro-naphthaline and the nitrate of aniline. And again, the 

 solid chlorates, perchlorates, or nitrates of potassium may be 

 used to oxidize bisulphide of carbon, benzole, nitro-benzole, 

 alcohol, ether, oils, etc. The best results were found from the 

 oxidation of the hydrocarbons by nitric acid. A mixture of 

 nitro-benzole with nitric acid (specific gravity, 1.5), when 



