For the grey bath, in twenty pails of the strong ley are mixed two pails of sheep's dung, two quarts of oil of vitriol, and one pound of gum arable and one pound of sal ammoniac, previously dis solved in a proper quantity of the weak ley ; and, lastly, twenty-five pounds of olive oil well mixed with two pails of the weak ley. The whole being well the i cotton is trodden down in it till it is well soaked, left thus for twenty-four. hours, and then wrung hard and dried. This operation is repeated a second and a third time, after which the cotton is well washed and dried.
The white bath, in which the cotton is next placed, is managed in every parti cular as the preceding, except that the sheeps' dung is omitted in it.
The gall bath, in which it is then put, is prepared by boiling twenty-five pounds of bruised galls in ten pails of river-wa ter until four or five are boiled away; the liquor is strained into a tub, and cold _ water is poured on the galls in the strainer. In this liquor, made milk warm, the cotton is to be dipped, hank by hank, and left to steep in it twenty four hours. It is then wrung carefully and equally, and dried well without washing.
For the first alum bath, twenty-five pounds of Roman alum are dissolved in fourteen pails of warm water, without making it boil : the liquor is well skim med, two pails of the strong ley are add ed, and the whole is let to cool till it is hike-warm. In this bath the cotton is dip ped, handled hank by hank, left to steep twenty-four hours, then wrung equally, and dried well without washing.
The second alum bath, to which it is next submitted, is managed exactly like the above : but after the cotton is dry, it is steeped six hours in the river, and then washed and dried.
Into the dyeing bath it is next put, by ten pounds at a time ; which is prepared by mixing two and a half gallons of ox blood with twenty-eight pails of milk warm water, adding twenty-five pounds of madder, and stirring all well together,.
The ten pounds of cotton, previously put on sticks, is dipped into this liquor, and turned constantly for one hour, du ring which the heat is gradually increased, till the liquor begins to boil at the end of the hour. The cotton is then sunk in it, boiled gently one hour longer, and then washed and dried.
For the next ten pounds of cotton, so much of the boiling liquor is taken out, that what remains may produce a luke warm heat with the fresh water with which the copper is again filled up, and then the dyeing liquor is made up as above.
For the fixing bath, five or six pails of the grey bath liqour, and as much of the white bath liquor, are mixed together ; in this the cotton is trodden down, left to steep six hours, and then wrung mode rately and equally, and dried without washing.
The brightening bath is prepared by dissolving carefully and completely ten pounds of white soap, in sixteen or eigh teen pails of warm water : if any little bits of the soap remain undissolved, they will make spots in the cotton ; four pails of the strong ley are added, and well stirred in. In this liquor the cotton is sunk, kept down with cross sticks, co vered up, and boiled gently two hours ; it is then washed and dried, which com , pletes the process.
For the common madder red, Mr. Wil son advises acetite of alumen to be used as the mordant, instead of alum. The cotton in his process is galled, dried, then impregnated with the acetite of alumen diluted with hot water ; dried a second time, maddered, washed, and dri ed again.
The scarlet colour communicated to cotton by cochineal is far from being per manent ; but if it is desired, Dr. Bancroft recommends the cotton to be first steep ed for half an hour in a diluted solution of murio-sulphate of tin, to wring it, and then plunge it into water, in which as much potash has been dissolved as will neutralize the acid adhering to the cotton, so that the oxide of tin may be more co. .piously fixed on its fibres ; the stuff rinsed in water is then to he dyed with cochi neal and quercitron bark, in the pro portion of four pounds of the former to two of the latter. A full bright colour is thus given, that will resist soap and the air.
With acetite of alumen, used as a mordant, cotton dyed with cochineal receives a beautiful crimson ; it will bear washing and the weather for some time ; but is not permanent. Dr. Bancroft thinks that a small portion of cochineal added, in dyeing madder reds on the finer cottons, would be highly advanta geous.
Of dyeing Wool yellow.