The Romance of Modern Chemistry

GREAT DISCOVERIES nitro-glycerine, for the absorbent kieselguhr is a neutral, harmless, non-explosive material. So, although it can take up as much as three times its quantity of nitro- glycerine, the explosive power of the latter is lowered by one-fourth. Nobel was therefore anxious to find as a substitute for kieselguhr some substance which would convert nitro-glycerine into a form suitable for safe handling and transport, and which at the same time, being itself explosive, would not diminish the effectiveness of the nitro-glycerine. The discovery of a material with the desired properties came quite by accident. Nobel cut his finger one day in the laboratory, and procured some collodion to paint over the cut and so form an artificial protective skin. Collodion, it should be stated, is a solution of a sub- stance resembling gun-cotton in a mixture of alcohol and ether; as these two liquids are very volatile, a film of collodion exposed to the air soon dries up and forms a skin. After Nobel had used a little of the collodion to paint over the wound, it occurred to him to pour what was left into a vessel containing nitro-glycerine. He did this, and observed that the collodion mixed with the nitro-glycerine and formed a jelly-like mass. This little observation was enough to show him the way in which the problem of the replacement of kieselguhr by a more active sub- stance could be solved. Experiments were carried out on a large scale, and these led to the manufacture of the explosive known as blasting gelatine, which is a mixture of nine parts of nitro-glycerine and one part of soluble gun-cotton. Pure blasting gelatine is so violent in its action that it cannot be used except for the hardest rocks; it was employed, for instance, in parts of the 337 y