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on woollen cloth, from a combination os two other dye;-',viz. by applying a full madder red upon a deep blueground. Both the blue and the madder red can be fixedupon linen as well as on woollen; and accordingly Itried compounding them on linen in different ways, some-times applying the red upon the blue, and sometimes theblue upon the red. In several of these experiments thelinen, as it came out of the dye, appeared of a good blackcolour, but on washing it, so much of the colour wasdischarged, that only a kind of dark purplish remained.

Some printed linens and cottons have a durable blackstain, which, as I am assured by a skilful and ingeniousartist, is made with madder and a solution of iron. Aquantity of iron is put into four strong beer; and to pro-mote the dissolution of the metal, the whole is occasionallywell stirred, the liquor at times drawn off, the rust beatenoff from the iron, and the liquor poured on again: a lengthof time is required for making the impregnation perfect,the solution being reckoned unfit for use till it has stood atleast a twelvemonth. This solution stains linen yellow,and of different shades of buff colour, and is the onlyknown material by which these colours can be fixed onlinen. The cloth, stained deep with the iron liquor,being afterwards boiled with madder, without any otheraddition, becomes of the dark colour which we fee onprinted linens and cottons, which, if not a perfect black,has a very near resemblance to it. It is submitted to theconsideration os those whom it may concern, whether thisfixt colour would not be preferable, on linen thread, tothe perishable black with which thread has hitherto beendyed. It is probable, that even a better black might thusbe dyed on thread, than that which the printer on linenproduces: for in this last business, while some parts of thelinen are stained deep with the iron liquor, in order to their

being