This preparation of copper is used in some fire-works. It communicates a green colour to flame. When combined with carbonaceous substances, the combustion is vivid. This is owing to the decomposition of the nitric acid, (in the same manner as the acid of nitrate of potassa and other nitrates is decomposed), during which carbonic acid and deutoxide of azote are produced. Nitrate of copper has been more particularly recommended for the preparation of match stick, similar to that of M. Cadet, and of match rope. It is used in the same manner as the nitrate of lead. M. Proust used it in lieu of nitrate of lead when repeating some experiments of M. Born. It is more expensive than the acetate, or even the nitrate of lead. Its effect, however, is the same. Nitrate of copper attracts the moisture of the atmosphere, and deliquesces. Acetate of lead, on the contrary, by exposure to the air gradually effloresces, and in time is decomposed. The preparations of lead, for that reason, are preferable to the nitrate of copper. Nitrate of copper is formed by dissolving copper in nitric acid; and, when the acid is saturated, the requisite quantity of water may be added. The salt may be obtained in a dry state by evaporation; and, after being dissolved in water, the wood or rope may be soaked in it. Dry nitrate of copper, wrapped up in tin-foil, will produce no action; but, if water be added, sufficient to moisten it, and then the foil closed tightly, combustion will take place. The water promotes chemical action by dissolving the nitrate of copper, which is then decomposed by the tin, and the quantity of caloric, put in a distributable state, is sufficient to inflame the tin. The details of the rationale will be given hereafter. The ammonia-nitrate of copper is fulminating copper. The chlorate of copper is a deflagrating salt. Ammonia added to nitrate of copper, first separates an oxide, and then dissolves it. It is more than probable, that nitrate of ammonia causes the ammonia-nitrate to explode. _Sec. LVIII. Of Strontia._ The earth called strontia or strontian, is found abundantly in different parts of the world, in combination with carbonic and sulphuric acids. The carbonate of strontia or strontianite, effervesces with acids, and burns with a purple flame. It contains about 60 or 70 per cent. of earth. The sulphate of strontia, or celestine, contains about 57 of strontia.