Fire, Yellow

Prep. 1. From sulphur, 16 parts; dried carbonate of soda, 23 parts; chlorate of pota a, 61 parts. 2. (March and.) Gunpowder, 14 parts; sulphur, 16 parts; dried soda, 20 parts; nitre, 50 parts. 3. (March and.) Charcoal, 1 1 ⁄ 2 parts; sulphur, 17 1 ⁄ 2 parts; dried soda, 20 parts; nitre, 61 parts. Green-coloured Fires. [310] | No. | Pota ium Chlorate, per cent. | Barium Nitrate, per cent. | Sulphur, per cent. | | 1 | 36 | 40 | 24 | | 2 | 29 | 48 | 23 | | 3 | 24 | 53 | 23 | | 4 | 21 | 57 | 22 | | 5 | 18 | 60 | 22 | | 6 | 16 | 62 | 22 | | 7 | 14 | 64 | 22 | | 8 | 13 | 66 | 21 | | 9 | 12 | 67 | 21 | | 10 | 11 | 68 | 21 | | 11 | 10 | 69 | 21 | | 12 | 9·5 | 69·5 | 21 | | 13 | 9 | 70 | 21 | | 14 | 8·5 | 70·5 | 21 | | 15 | 8 | 71 | 21 | [310] Kern (‘Chemical News,’ September 29th, 1876). Red-coloured Fires. | No. | Pota ium Chlorate, per cent. | Strontium Nitrate, per cent. | Sulphur, per cent. | Carbon Powder, per cent. | | 1 | 40 | 39 | 18 | 3 | | 2 | 32 | 46 | 19 | 2 | | 3 | 27 | 51 | 20 | 2 | | 4 | 23 | 55 | 20 | 2 | | 5 | 20 | 58 | 20·5 | 1·5 | | 6 | 18 | 60 | 21 | 1 | | 7 | 16 | 61·6 | 21·2 | 1·2 | | 8 | 15 | 63 | 21 | 1 | | 9 | 13 | 64 | 22 | 1 | | 10 | 12 | 65 | 22 | 1 | | 11 | 11 | 66 | 22 | 1 | | 12 | 10 | 67 | 22 | 1 | | 13 | 10 | 67·25 | 22 | 0·75 | | 14 | 9·25 | 68 | 22 | 0·75 | | 15 | 9 | 68·35 | 22 | 0·65 | Violet-coloured Fires. | No. | Pota ium Chlorate, per cent. | Calcium Carbonate, per cent. | Malachite powdered, per cent. | Sulphur, per cent. | | 1 | 52 | 29 | 4 | 15 | | 2 | 52 | 28 | 5 | 15 | | 3 | 52 | 26 | 7 | 15 | | 4 | 52 | 24 | 9 | 15 | | 5 | 52 | 23 | 10 | 15 | | 6 | 52 | 21 | 13 | 15 | | 7 | 51 | 20 | 14 | 15 | | 8 | 51 | 18 | 16 | 15 | | 9 | 51 | 16 | 18 | 15 | | 10 | 51 | 15 | 19 | 15 | | 11 | 51 | 13 | 21 | 15 | | 12 | 51 | 11 | 23 | 15 | | 13 | 51 | 10 | 24 | 15 | | 14 | 51 | 8 | 26 | 15 | | 15 | 51 | 6 | 28 | 15 | 4. (Marsh.) Charcoal, 6 parts; sulphur, 19 1 ⁄ 2 parts. For pans. Very beautiful. In preparing coloured fires for fireworks according to the usual formulæ given in manuals of pyrotechny, it is often important to know the speed at which they burn; as in some cases, such as decorations and lances, they should burn slowly; whereas in others, such as wheels, stars for rockets, and Roman candles, they ought to burn quicker. The foregoing tables are so arranged that every formula with a higher number yields a slower burning mixture than one with a lower number. Thus No. 5 burns quicker than No. 6, and slower than No. 4. Obs. The ingredients in the above compounds are to be separately reduced to powder and sifted through lawn, after which they should be kept in well-corked wide-mouthed bottles until the time of mixing them for use. The chlorate of pota a, more especially, must be separately treated and cautiously handled, in order to prevent the po ibility of explosion from friction whilst it is in contact with combustible matter. The requisite quantity of each of the ingredients being weighed out and placed on a clean sheet of white paper, the whole is to be thoroughly but carefully mixed together with a light hand, by means of a bone or wooden knife. The compound is next lightly packed into small cups or pans for illuminations, or into small pill-boxes for stars and trains, a little priming and quick-match being lastly attached to each. To ensure succe the several ingredients must be dry and commercially pure; and though reduced to the state of a uniform powder, care must be taken that they are not absolutely ‘dusty,’ or too finely pulverised. The nitrate of strontia, alum, saltpetre, carbonate of soda, ., before being weighed, require to be gently heated in an iron pot or pan until they fall to powder, and lose their hygrometric moisture, or water of crystallisation. To ensure the perfect admixture of the ingredients, the whole, after they have been stirred together on paper, as before directed, may be pa ed through a hair or perforated zinc or bra sieve. Further, as coloured fires rapidly deteriorate by keeping, and even sometimes inflame spontaneously, to prevent disappointment and accidents they should not be prepared long before they will be required for use, and should be stored in some situation in which their spontaneous combustion would be productive of no disastrous consequences. Of the above formulæ, those bearing the name of the late Mr Marsh, of Woolwich, more especially deserve the attention of the pyrotechnist. To guard against the danger sometimes arising from the spontaneous combustion of coloured fires containing sulphur and chlorate of potash, Mr Saunders recommends intimately mixing 120 grains of bicarbonate of potash with each pound of sulphur before using it in the manufacture of any composition into which chlorates enter. See Flame , Pyrotechny , .