base of ammonium is very useful in compositions containing copper. Its place is now generally taken by calomel; in such compositions chloride of sodium had been used for many years, but not as a chlorine carried. Ruggieri appears to have been the first to produce colour on anything approaching modern lines, and although he did not progress greatly, what he did achieve was undoubtedly a marked advance in the art.
His account of the invention of this composition is interesting. He says that he was told by a returned traveller from Russia of a set piece representing a palm tree, "the colour of which rivalled nature." This piece he set out to imitate, which he did, at any rate to his own satisfaction. The result he obtained would undoubtedly give a good colour, if the method of firing was very clumsy. He remarks that he does not know if his method was as that adopted in Russia, and later of the "merit if not of discovering a new fire at least to have imitated or rather to have rediscovered it." It appears, therefore, that there may be some doubt as to the originality or priority of Ruggieri's achievement in this direction, but he must be credited at least with independently arriving at the result. Indeed it is more than probable that the piece seen in Russia was quite different, a transparency or illumination, either imported or copied from the work of Eastern pyrotechnists, and that the whole credit of introducing colour into the art belongs to Ruggieri and to him only.
He mentions that he puts it on record with the object of "thus preventing writers from attributing it to the Chinese, the Medes, or Arabs, as is the custom in Europe, and above all in France, where more than elsewhere there is a mania for enriching foreigners with our merits and to rob ourselves of the birthrights of genius."
