The Chemistry of Powder and Explosives - Sciencemadness Dot Org

42 BLACK POWDER
hexagonal or octagonal prisms which resembled pieces of milk
chocolate. A partially burned brown charcoal made from rye
straw was used. This had colloidal properties and flowed under
pressure, cementing the grains together, and made it possible to
manufacture powders which were slow burning because they contained
little sulfur or sometimes even none/ The compositions of
several typical cocoa powders are tabulated below:
BROWN
SALTPETER CHARCOAL SULFUR
England '79 18 3
England 77.4 17.6 5
Germany 78 19 3
Germany 80 20 0
France 78 19 3
Cocoa powder was more sensitive to friction than ordinary black
powder. Samples were reported to have inflamed from shaking in
a canvas bag. Cocoa powder was used in the Spanish-American
war, 1898. When its use was discontinued, existing stocks were
destroyed, and single grains of the powder are now generally to
be seen only in museums