23. And now comes the last, and, in my opinion, the most beautiful
colour of all. This is the blue. It has generally been considered a very
dangerous colour, but the following formulas I have always found
thoroughly safe:—
BLUE STARS.
No. 7.
Chlorate of potash 8 parts.
Sulphide of copper 6 „
Chertier’s copper 5 „
Sulphur 4 „
Or,
No. 8.
Chlorate of potash 12 „
Chertier’s copper 6 „
Sulphur 4 „
Calomel 1 part.
These formulas give a rather pale but very brilliant blue. The
compositions have the advantage of being very readily ignited.