This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Flashlight Compounds. It is not advisable for anyone to make their own mixtures, for if the process be not thoroughly understood and proper care exercised, there is great danger of serious accident resulting. Chlorate of Potash requires cautious handling. Excellent flashlight mixtures are on the market and obtainable from all dealers at a price fully as reasonable as you would be able to purchase the separate ingredients and mix them yourself. Mixtures and compounds must not, under any circumstances, be employed in the lamp intended for magnesium powder. If used in such lamps as soon as the powder is ignited an explosion would immediately occur. Specially constructed lamps are made for flashlight compounds, which are operated in one of three ways. In all instances, however, the powder is spread out over a flat surface, and not concealed in a closed chamber, as is the magnesium.
479. The first, and most popular, method employed for igniting flashlight compounds, is to employ an alcohol flame. The alcohol flame is perfectly protected from the pan containing the powder and the flame is blown into the powder by means of a blow-pipe, thus igniting it. A second method is where an iron rod is automatically heated over the alcohol flame and when it is desired to make the flash, this red hot iron is forced into the powder. There is still another method where an electric current is employed, a fine piece of platinum wire being inserted underneath the powder between two binding posts. When the switch is set and the circuit completed, the electric current will heat the platinum wire red hot, thus setting off the powder.
480. A very simple flash-pistol is manufactured by the Eastman Kodak Company and sells for 50 cents. With this pistol any work on a small scale can be accomplished with little or no danger to the user. See Illustration No. 32. For larger work or purposes requiring more powder than the small cartridges contain, the style "D" Luxo lamp will be found very serviceable. See Illustration No. 33. If it is not possible to purchase a lamp in which to use the flashlight compound, an apparatus may be very easily constructed at home at little cost. A stand of some kind upon which to place the flashlight is essential, as it will be necessary to vary the height of the flash. A tin dust pan or a large sheet of tin or zinc may be placed on top of a box, small step-ladder, or some such support, which may be regulated at various heights, and the powder spread out on this pan or sheet of metal.
Illustration No. 33 See Paragraph No. 480.