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The Chemistry of Powder and Explosives - Sciencemadness Dot Org

The Chemistry of Powder and Explosives - Sciencemadness Dot Org

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EARLY HISTORY OF COLLOIDED POWDERS 293<br />

, . , This substitution has had the foreseen consequence <strong>of</strong><br />

suppressing- the smoke from the shooting. 4<br />

<strong>The</strong> author <strong>of</strong> the note in the Memorial des poudres in which the<br />

above-quoted public announcement was made concerning the new<br />

powder was so impressed by the importance <strong>of</strong> the invention that<br />

he concludes the note by saying:<br />

It results from this that the adaptation to firearms <strong>of</strong> any<br />

other explosive known at the present time would be able to<br />

bring to the armament only a perfectioning <strong>of</strong> detail, <strong>and</strong><br />

that a new progress, comparable to that which has been<br />

realized recently, cannot be made except by the discovery<br />

<strong>of</strong> explosives <strong>of</strong> a type entirely different from those which<br />

chemistry today puts at our disposition,<br />

French powder for the military rifle consists <strong>of</strong> small square<br />

flakes lightly glazed with graphite. <strong>The</strong> glazing serves to retard<br />

slightly the rate <strong>of</strong> burning <strong>of</strong> the surface layer, <strong>and</strong>. more important,<br />

it serves to make the powder electrically conducting <strong>and</strong> to<br />

prevent the accumulation <strong>of</strong> a static charge during the blending<br />

<strong>of</strong> small lots <strong>of</strong> the powder into a single, ballistically uniform<br />

large lot. For guns the powder consists <strong>of</strong> unglazed strips. <strong>The</strong><br />

squares <strong>and</strong> strips, ignited over their entire surfaces, burn for<br />

lengths <strong>of</strong> time which depend upon their thicknesses, <strong>and</strong> they<br />

retain, during the burning, surfaces which change but little in<br />

area until at the end the grains are completely consumed.<br />

1888. <strong>The</strong> second successful dense smokeless powder was the<br />

ballistite which was invented by Alfred Nobel. 5 This was a stiff<br />

gelatinous mixture <strong>of</strong> nitroglycerin <strong>and</strong> soluble nitrocellulose in<br />

proportions varying between 1 to 2 <strong>and</strong> 2 to 1, prepared with<br />

the use <strong>of</strong> a solvent which was later removed <strong>and</strong> recovered.<br />

Nobel appears to have been led to the invention by thinking<br />

about celluloid, for the patent specification states that the substitution<br />

<strong>of</strong> almost all the camphor in celluloid by nitroglycerin<br />

yields a material which is suitable for use as a propellant. In the<br />

method <strong>of</strong> manufacture first proposed, camphor was dissolved in<br />

nitroglycerin, benzene was added, <strong>and</strong> then dry, pulped, soluble<br />

nitrocellulose; the mixture was kneaded, the benzene was allowed<br />

to evaporate, <strong>and</strong> the material was rolled between warm rollers<br />

*Mem. poudres, 3, 11-12 (1890).<br />

5 Brit. Pat. 1471 (1888).

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