Picrate whistles

Non-picrate whistles, made from a mixture of 1 part powdered gallic acid and 3 parts potassium chlorate, are considered to be safer than those which contain picrate. The mixture is charged into a %-inch case, 5/16 inch in internal diameter. The case is loaded on a 1-inch spindle, and the finished whistle has a 1-inch length of empty tube which is necessary for the production of he sound. Whistles of this sort, with charges of a chlorate or perchlorate explosive at their ends, are used in chasers, whizzers, etc., which scoot along the ground while whistling and finally explode with a loud report. 

Potassium chlorate Picrate whistle Potassium picrate Potassium nitrate Benzoate whistle Potassium benzoate Potassium perchlorate 70... 

The gallic and picrate whistles mentioned above are sensitive to mechanical action.The gallic whistle composition has almost the same sensitivity to shock as the picrate whistle. To... 

In World War II, the Germans used picrate whistles as a psychological adjunct to bombs and they also used pyrotechnic whistles as gas alarms. In this country, the M] 19 Whistling Booby Trap Simulator, ignited by a pull cord, produces a shrill whistling sound for 31/2 sec from a 2-in. column of Formula 156. The A/I17 Booby Trap Fksh Simulator, pull-cord ignited, starts with a whistling sound followed by an explosive flash. 

K picrate was used as early as 1869 in expls, such as poudres Designolles (K picrate + K nitrate + charcoal) and poudres Fontaine (K picrate + K chlorate). It has also been used in pyrotechnic whistle compns (Ref 8), proplnts such as Ballistite, and in some primer mixts, ie, K picrate, Pb picrate K chiorate (Ref 4)... 

All whistle compositions are hazardous to handle, but those containing picrates and gallates are also shock-sensitive with a tendency to explode. Picric acid (2,4,6-trinitrophenol) is, in fact, classed as a high explosive. 

O. Comp per miscele sibilanti (Compns for whistling mixtures) a) K picrate 70 NaN03 30% b) Gallic acid 50 KC103 50% (Izzo, p 226)... 

Picric acid is used for manufacturing potassium picrate for whistles. It is sometimes used as a combustion agent for black snakes. Wlien handling picric acid ordinary metallic containers or tools must be avoided. 

Materials and labour enter into the left(debit) side and come out of the right(credit) side as finished goods. Practically energies like power or heat and the loss of tools, furniture, fixtures and structures should be added to the left side, but these are quite small in firework manufacture-The operations which move the left side elements to the right are almost all physical and are seldom chemical. For example, the manufacture of potassium picrate as the material for whistles or the nitration of pitch for black snakes belong to the chemical operation. 

Generally speaking, the composition which is sensitive to shock is also sensitive to friction. On the contrary the one which is insensitive to shock is also insensitive to friction, but there are some types which do not follow this rule a whistle composition consisting of potassium picrate and potassium nitrate is sensitive to shock but insensitive to friction the thermit compositions, especially red thermit which consists of red lead and ferro-silicon, are quite insensitive to shock but sensitive to friction. 

Whistling squibs are made with magnesium picrate. The mixture is prepared according to the formula of the inventor, Weiffenbach, of Stuttgart. T%vo hundred grams of picric acid and 800 g. of nitre are dissolved in hot water, and saturated with 30 g. of magnesium carbonate, and the precipitated crystals then dried. 

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