DYE

DYE

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large quantity of tan, and above all, galls, fe-condly, an aluminous mordant added to thegalled cotton, generally with a certain portionof tartar; thirdly, the madder colouring mat-ter, and fourthly, a finilli with an alkalinebath, which indeed is not effential to thefixity of the colour, but is found moft mate-rially to heighten and improve it, chiefly as hasbeen fuppofed by removing the brown-yellowpart of the madder which always mixes more orlefs with the red, and degrades it. The othermadder colour is a very bright, beautiful, andmoft durable red, which, from having long been,and being Hill prepared at Adrianople , andother parts of the Levant, with a perfe£tionfcarcely imitable, is called th e Adrianople or TurleyRed, and if the accounts of its preparation areaccurate, it is the molt complicated and tediousprocefs in the whole art of dyeing.

The true Adrianople red, befides its uncom-mon beauty, has the property of refilling morethan any other m adder red, the action of foap,alkalies, alum, acids, and all other reagents. Onthis account nitric acid is employed as a tell todiltinguilh this red from any fpurious imitations.If the latter is immerfed in aqua-fortis, or com-mon nitric acid, it foon lofes colour, and inabout a quarter of an hour it is quite white,whereas the genuine Turkey red cotton will re-main nearly an hour without any perceptible lofsof colour, and retains an orange tint to the lalt.

There can be no doubt too that much of thebeauty of the Levantine red is owing to thefuperior quality of the madder, as will be noticedunder that article, fo that even with the beltmadder of the North of Europe , it is probablethat no accuracy in the dyeing can entirelymake up for this radical difference.

We fhall not detail the feventeen diltinft ope-rations (given by the Abbe Mazeas) as employedin this procefs, but only defcribe the generalway of proceeding.

The cotton yarn is firlt thoroughly cleanfedby long boiling in water. The next ftep is toimpregnate it with an animal fubftance, which,having a much Itronger affinity for colouringmatter than the cotton itfelf, forms an excellentballs or fubftratum on which the dye may fixitfelf by the fubfequent operations. The animalmatter in this inftance is fheep’s dung. Oil isanother intermede alfo ufed, and the effedt ofthis is certainly to affilt in fixing the colour,and rendering it afterwards infoluble in allother fubllances. The oil and the dung areblended, and both together diffolved in a ley offoda, and the cotton well mixed with it withmuch manual exertion.

The cotton is then fteeped in olive oil, with-out the dung, brought to the Hate of a milkyliquid, or an extemporaneous foap, by juft fu(h-cient foda. It is then fteeped in three iucceffivebaths of foda and water, each Itronger than thelalt, in order thoroughly to feparate all the oilthat loofely adheres to the cotton, or all butwhat is intimately combined with it. This isneceflary to make it take up the foluble part ofthe galls with which it is combined in the nextoperation. A Itrong decodtion of galls is then,made, and the cotton is long and thoroughlyfteeped in it, with much wringing and prelling,after which it is ftretched and dried as quicklyas poffible.

The cotton now may be confidered as a com-pound of vegetable fibre with the animal mat-ter of dung, with oil, and with tan very inti-mately combined, and it is then in the Hate fitto receive the proper mordant for the maddercolour. This mordant is Roman alum, in whichthe cotton is carefully fteeped for a due time,and then ftretched and dried.

After this long preparation the cotton under-goes an exadt repetition of the whole procefsftep by ftep, the dung bath only excepted; thatis, of oiling, fteeping in foda, galling and alu-ming.

The whole of this labour being performed,the cotton is thoroughly dried and aired, and isthen of a dun or root colour, this hue beinggiven by the galls. The next ftep is the mad-dering, but in order more fully to animalize thecotton a fmall quantity of fheep’s blood is mixedwith the water in the boiler in which themadder is diffolved. The felcction of themadder depends on the precife colour requiredto be given; the quantity is always twice theweight of the cotton. When this bath has gotto a lukewarm heat the hanks of cotton arefteeped in it well ftretched on wooden frames,that keep the thread fufficiently afunder toallow the dye to penetrate thoroughly and uni-formly.

This fteep lafts an hour, during which theheat of the bath is flowly increafing, and afterit begins to boil, the cotton is taken off theframe and let to lie loofe in the veffel for anhour longer, the liquor being all the while keptat a boiling heat. After this, the colour of thebath being exhaufted, the cotton is taken outand waftied in running water, ftretched, anddried. Laftly the cotton, now thoroughly anddurably dyed, is finifhed by being boiled forfour or five hours in a clofely covered veffel in afolution of white Marfeilles foap, olive oil, add2 B %