444 Guncotton and Nitroglycerine. [Jan. 29, 



ring orange-coloured fumes of nitric peroxide are evolved. When 

 the temperature exceeds 82^ C, the test is complete and the flask is 

 withdrawn. The number of hours which have elapsed since the start 

 of the test is the measure of the stabihtj of the cordite. 



Until about 60 vears ago, the onlv explosive known, for all pur- 

 poses, was gunpowder. With the discovery of guncotton and nitro- 

 glycerine, gunpowder was gradually replaced by them for blasting 

 purposes. In their early days the two explosives were used singly, 

 guncotton as guncotton, nitroglycerine — first of all alone — and then 

 as dynamite. Later on, the two were combined as blasting gelatine, 

 and explosives of a similar nature, but it was quite 40 years after their 

 discovery before either became of practical use for propulsive 

 purposes. 



The invention of " Poudre B "' by Yieille marked the commence- 

 ment of a new era in connection with the science of artillery, and it 

 was not long before smokeless powders made from the violent gun- 

 cotton or of guncotton combined with the still more violent nitro- 

 glycerine, entirely superseded the centuries-old gunpowder. Modern 

 explosives are characterised by very greatly increased power, giving 

 enormously greater range to projectiles fired from both rifles and 

 artillery, thus altering entirely the conditions of both land and naval 

 warfare. 



It is at present not easy to forecast in what direction further im- 

 provements in propellants will take place. It is also difficult to con- 

 ceive what the explosive of the future will be which shall produce a 

 change as revolutionary as that which took place when smokeless 

 powders superseded the old-fashioned black powders. For some time 

 to come, probably, the manufacturer of explosives will have to content 

 himself with endeavours to improve them as far as he can both from 

 a ballistic and from a stability point of view, with the ingredients now 

 at his disposal. 



[F. L. N.] 



