The Chemistry of Powder and Explosives - Sciencemadness Dot Org

PYROTECHNIC MIXTURES 61
positions which contain potassium chlorate. Meyer states, incidentally,
that the English at that time used colored rockets for
signaling at sea and were able to produce ten distinguishable
shades. His descriptions of his compositions give one reason to
suspect that he had had little experience with them himself. The
first, a mixture of potassium chlorate and sugar, burns, he says,
with a red light; but the color is actually a bluish white.
A powder which burns with a green flame is obtained by
the addition of nitrate of baryta to chlorate of potash,
nitrate of potash, acetate of copper. A white flame is made
by the addition of sulfide of antimony, sulfide of arsenic,
camphor. Red by the mixture of lampblack, coal, bone ash,
mineral oxide of iron, nitrate of strontia, pumice stone, mica,
oxide of cobalt. Blue with ivory, bismuth, alum, zinc, copper
sulfate purified of its sea water [sic]. Yellow by amber, carbonate
of soda, sulfate of soda, cinnabar. It is necessary in
order to make the colors come out well to animate the combustion
by adding chlorate of potash. 15
Although Meyer's formulas are somewhat incoherent, they represent
a definite advance. Equally significant with the use of
chlorate is his use of the nitrates of strontium and barium.
The second German edition of Ruggieri's book (we have not
seen the first) contains a Nachtrag or supplement which lists
nine compositions, 10 of which four contain Kali oxym. or potassium
chlorate. These are: (1) for red fire, strontium nitrate 24
parts, sulfur 3, fine charcoal 1, and potassium chlorate 5; (2) for
green fire, barium carbonate 20 parts, sulfur 5, and potassium
chlorate 8 parts; (3) for green stars, barium carbonate 20 parts,
sulfur 5, and potassium chlorate 9 parts; and (4) for red lances,
strontium carbonate 24 parts, sulfur 4, charcoal 1, and potassium
chlorate 4 parts. Ruggieri says:
The most important factor in the preparation of these
compositions is the fine grinding and careful mixing of the
several materials. Only when this is done is a beautiful flame
to be expected. And it is further to be noted that the potassium
chlorate, which occurs in certain of the compositions, is
to be wetted with spirit for the grinding in order to avoid
an explosion.
15 Brock, op. cit., pp. 145, 146.
16 Ruggieri, op. cit., pp. 147, 148.