On .a new method of colouring or Ornamenting Steel. By AL Leopold Nobili, of Reggio, in Italy.
In the Bulletin de In Soeieli ir Encouragement, for January 1829, is contained a report made by 111. Gualthier de Claubry, a member of that society, as follows: " A learned foreigner, known by his ingenious re searches, M. Leopold Nobili, having presented to this society the results of his experiments relative to a new art, to which he has given the name of mliallochromie; you charged your committee of the chemical arts to examine these products; and I have, in its name, to report thereon.
" A great number of experiments, more or less successful, have been made by various persons, and at different periods, to apply, in a solid manner, paintings upon metals; but the solidity of the pictures did not equal their wishes, and the thinness of the co lours applied rendered their traces vague, and greatly diminished the sharpness and finish of the designs.
" M. Nobili has lately, by his assiduous researches, and the labour of many years, produced, by a process which lie has not made known, designs upon various metals, in which the brilliancy of the colours, and the harmony of the tints, leave nothing to be desired; thus these colours possess none of the inconveniences above stated; and they are developed upon the surface of the metals without being too thinly diffused; but are stable, and will not disappear unless by the appli cation of a high red heat, which, by its action, would also destroy the surface of the metal, as well as the chemical agents employed upon it.
" Nothing can he more brilliant and singular than the colours upon M. Nobili's plates, especially by day light; and all his designs are executed with a fine taste, the regularity of their forms, and the sharpness of their outlines, being all that can be wished.
" M. Nobili has not merely manufactured these plates as objects of curiosity, but has mounted several, which have been singularly esteemed by amateurs; and we can readily believe that this pleasing art would meet with great success were it carried into effect on a proper scale; and it is, therefore, much to he de sired that so new and curious an art should not be lost to France, and especially as M. Nobili appears dis
posed to bring it into practice. We can easily form a just idea of the extent to which it might be to carry this branch of manufacture, when we remark. that many metals assume their colours in very dif ferent orders by the application of heat; and we can easily conceive, that in the hands of a skilful man, and one well conversant with commerce, the greatest advantages might be derived from the employment of this new branch of industry. Thus, for instance, no thing presents more harmony than gold, as its tints are very different from those afforded by heating steel. It is upon this last metal that all the designs pre sented by M. Nobili have been executed. Silver like wise affords different colours on applying heat; and an experienced artist cannot fail to make many fine applications of M. Nobili's process.
" This process not being exactly known, many persons have accordingly formed suppositions, and even made experiments respecting it; but it does not appear that their suppositions have been well founded; and their success has been much less happy, and their colours less perfectly developed upon the surface of the metal, than can be effected by an art which has acquired perfection in the hands of Nobili.
" Under the impossibility, then, of being able to speak positively as to the manner in which M. Nobili has been able to produce these curious effects, we can only applaud the incessant efforts which he must have made to bring his art into the perfect state in which we find it. All those, Who have attempted new branches of manufactures, may well conceive the dif ficulties which every day presents, and which can only be overcome by a continued zeal and efforts to surmount unsuccessful endeavours; and M. Nobili could not otherwise have arrived at the point of per fection to which he has brought his ratalloehromie, nor can he be too much praised for the success he has obtained.