Nitroglycerine is an explosive liquid which was first made by
Ascanio Sobrero in 1846 by treating glycerol with a mixture of
nitric and sulphuric acid. The reaction which follows is highly
exothermic, i.e. it generates heat and will result in an
explosion of nitroglycerine, unless the mixture is cooled while
the reaction is taking place. Liquid nitroglycerine is colorless
if pure. It is soluble in alcohols but insoluble in water.
Nitroglycerine is extremely sensitive to shock and in the early
days, when impure nitroglycerine was used, it was very difficult
to predict under which conditions nitroglycerine would explode.
Alfred Nobel studied these problems in detail, and was the first
to produce nitroglycerine on an industrial scale. His first major
invention was a blasting cap (igniter), a wooden plug filled with
black gunpowder, which could be detonated by lighting a fuse.
This in turn, caused an explosion of the surrounding
Alfred Nobel worked hard to improve nitroglycerine as an explosive that could be used in blasting rock and in mining. He made one of his most important discoveries when he found that by mixing nitroglycerine, an oily fluid, with kieselguhr, the mixture could be turned into a paste. This material could be kneaded and shaped into rods suitable for insertion into drilling holes. He called his paste dynamite and went on to develop a blasting cap which could be used to detonate dynamite under controlled conditions.