EXPLOSIVES : MANUFACTURE AND USE. 247 



rockets, compressed gases, shells, military and sporting car- 

 tridges of all kinds, caps, fuses, and blasting compounds — the 

 latter infinite in variety. I propose to limit myself to those 

 which are of purely South African interest, but even this is a 

 very wide field. The base of all is nitro-glycerine, or gun- 

 cotton, or both. 



Nitro-giycerine was discovered in 1846 by an Italian chemist 

 called Sobrero, and although he recognised its explosive pro- 

 perties, he was not able to apply his knowledge. For many 

 years its only application was medicinal, and it still figures in 

 the British Pharmacopia. To Alfred Nobel, than whom no 

 more daring experimenter ever breathed, belongs the merit of 

 developing its latent potentialities. I remember vividly his 

 relation of some of his early experiments. It may seem a 

 small thing to say that he distilled over hundredweights of 

 nitro-glycerine under reduced pressure, but this he actually did. 

 and only those who know what a ticklish body nitro-glycerine 

 is can realise the daring of the experiment. It had apparently 

 a great future. Factories for its manufacture were established 

 everywhere. True, the quantities made at a time were not 

 large — a few lbs. being generally the limit. Nowadays in 

 America they make two tons in one operation. Here in South 

 Africa we are content with one ton. I might explain that in 

 these early days nitro-glycerine was handled in much the same 

 manner as paraffin oil is to-day. To make the comparison com- 

 plete, it was generally transported in paraffin tins, and the 

 precautions observed were not so g'reat as those which obtained 

 for the carriage of eggs. Railway contractors, however, 

 generally made it as they went on with their work — certain men 

 skilled in the art, but mostly unskilled — following up the con- 

 tractors and supplying them with what they wanted. But a 

 rude awakening was at hand. Accidents of the most appalling' 

 nature were reported from all corners of the civilised world. 

 Of these England had her share, and the Government of the 

 time became so alarmed by these occurrences that they ap- 

 pointed in 1874 a Select Committee to investigate and report. 

 That committee recommended the absolute prohibition of 

 manufacture, and much the same course was followed by other 

 countries. Any ordinary man would have been deterred from 

 going further — but not , Nobel, who had set his heart on the 

 taming of the shrew. This he succeeded in doing after many 

 failures, and his dynamite of 1867 is the selfsame dynamite 

 which made mining at depth possible in Kimberley and else- 

 where. Dynamite is nothing more nor less than nitro-glycerine 

 absorbed by a body called Kieselguhr — Fuller's earth— whicli 

 is composed of the skeletons of tiny animalculje. These ha\e 

 a remarkable absorptive capacity, and as a matter of fact soak 

 up three times their own weight of nitro-glycerine — which is 

 dynamite. 



For the moment I leave nitro-glycerine and pass on to the 

 other base, guncotton — which is really a generic term for a 

 wdiole series of bodies. Physically all look exactly the same^,^-jrr]S~"*"-^ 

 but in their chemical properties they are as far apart as >tfeO^H*v^/ 



L I S R A R *t 



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