Concerning all these different branches, one general observation will suffice; namely, that those who are concerned in them have, for the most part, obtained, their knowledge of the art of dyeing, not from theories adapted to explain the different processes, but from practice in that branch in which they are occupied. They usually, therefore, perform those processes which they have been shewn and told, without any inquiry into the causes which produce the results. There are, it is admitted, exceptions to this, men of general information and knowledge being occasionally found in the various branches of dyeing, but they are so few, that it may be questioned, when compared with the great body employed in the art, whether they amount to one in a thousand. This is not, however, to be attributed to any indifference in such persons to acquire a correct knowledge of the art, but is chiefly owing to a deficiency of the ready means of acquiring such information; which information it is the design of the present Treatise to supply; there not being, as far as the present writer knows, any such work, at a moderate price, to be obtained in the English language. It is true many of the _Cyclopædias_ furnish us with much useful information on the subject of dyeing: one of these, JENNINGS'S _Family Cyclopædia_, may be particularly mentioned as containing such; but it is scattered about in these dictionaries in various ways, at once troublesome and unpleasant to obtain. Dr. BANCROFT'S work on the philosophy of _Permanent Colours_, in two octavo volumes, will also supply much valuable information; so also will the edition, some time since published, of BERTHOLLET'S _Elements of the art of Dyeing_, with the addition of valuable _Notes_ by Dr. URE. Dr. URE'S _Chemical Dictionary_ is also very useful to the dyer, us well as many detached papers in several of our English publications. A _Treatise on Printing and Dyeing Silks, &c._ lately published by H. M'KERNAN, is also valuable, and should be consulted by the curious in this art. But all these works are expensive, and such as few dyers will be disposed to obtain; hence the necessity of the present Manual, the author of which has not servilely followed the directions or recommendations of any previous writer; but from his own practice, a practice of more than thirty years, has laid down such rules as he knows to be at once practical and efficient. At the same time he thinks it right to state, that he has not only consulted all the works mentioned above, but also _Hellot, Macquer, &c._ adopting all that appeared essential in these, and giving such additions as accord with the present improved state of chemistry and dyeing; and, as far as was possible, in the limits prescribed for this work, so that it may be within the reach of every dyer in the kingdom, as well as every journeyman and apprentice in all the various branches of this truly extensive and mysterious art, as carried on in London,