Immerse hanks of scoured silk for a quarter of an hour in a weak solution of _acetate of lead_ at the ordinary temperature; take them out and wash them in a great deal of water: then dip them into a weak solution of _chromate of potash_. They immediately take a fine yellow colour; at the end of ten minutes the effect is complete. From this colour being decomposed in part by soap and water, it is chiefly applicable to silks. But by applying, however, a mordant of acetate or nitrate of lead, and passing the goods through bichromate of potash, a very beautiful and sufficiently fast yellow is now given to _cotton goods_ in this country. _Conclusion._ We cannot conclude our work without observing, that from the researches continually going on in _botany_ and other branches of natural history, and, more especially, from those in _chemistry_, there can be no doubt that discoveries, which will materially improve the art of dyeing, must, from time to time, be made. Some of these, not yet generally known, in the hands of a few persons, have already been found useful; but individual interest is, of course, a great enemy to their being made public. Others, although public, are, as yet, of too doubtful a utility to be noticed here. If we have not given forms for the employment of some articles in use by certain dyers, such as _kermes_ for _reds_; _French Berries, (rhamnus infectorius,)_ the _Canada golden rod (solidago Canadensis,)_ the _Barberry (Berberis vulgaris,)_ and the _French marygold, (Tagetes patula,)_ for _yellows_, &c. &c.; it is not to be concluded that such are not good in their kind, and might not be used occasionally with advantage. But as our object has been to give the _best_ methods of dyeing the various colours, it would be impossible to notice many others in a manual of this kind, and in the limits within which we are necessarily confined. To mention those substances recently introduced into dyeing, the utility of which is not confirmed by extensive practice, would be injudicious, and tend to lead the young dyer astray; those, however, who have leisure and inclination, and are, besides, able to run the risk of the failure of new processes, may, and no doubt will, make experiments with them by which our art must be eventually served and improved. INDEX. Acetate of alumina, 8, 36 copper, 16 lead, 17 Acid, the acetic, 33 carbonic, 32 Gallic, 10 muriatic, 12 nitric, ib. nitro-muriatic, 13 pyrolignous, 33 sulphuric, 15 Tartaric, 33 Acids, what, 31 Adjective colours, 27 Adrianople red, 117 Albumen, 24 Alcohol, what, and how obtained, 25 Alkali, volatile, 23, 30 Alkalies, the fixed, 14, 30 Alum, common, 7 roche, ib. Alumina, ib. acetate of, 8 American bark, 15 Ammonia, 23 carbonate of, ib. Animal substances, analysis of, 18 oil, 24 Annatto, preparation of, 136 Aqua fortis, 13 regia, ib. Archil, 8 Argol, ib. Aurora, to dye silk, 137 Azotic gas, 29