DYEING. 



255 



Remark by Dr Bancroft." The steep here pre- 

 scribed, contains three ingredients not employed, so 

 tar as I can recollect, by any other person ; and one of 

 these, I mean the sulphuric acid, seems to indicate a 

 want of chemical knowledge in M. Papillon; because, 

 by neutralizing the soda, it must obstruct the effect 

 which the latter is intended to produce, (that of ren- 

 dering the oil miscible with water,) or at least, render 

 a greater proportion of it necessary, in order to obtain 

 that effect. In regard to the other two ingredients, 

 viz. the gum and sal ammoniac, I shall only observe of 

 the former, that the quantity is by much too small to 

 produce any considerable effect, either good or bad, 

 without offering any opinion of the latter, because I 

 am unable to form even a conjecture, respecting the 

 purpose which it may have l>een intended to answer. 

 Did M. Papillon wish, by these additions, to give to his 

 process some appearance of novelty or peculiarity which 

 might render it more deserving of a reward? At Rouen, 

 the bain bit is prepared by steeping twenty-five or 

 thirty pounds of sheep's dung several days in a ley of 

 soda, marking four degrees, which is to be afterwards 

 dilated until it amounts to forty gallons ; and the 

 dung being squeezed, and broken by the hands, is af- 

 terwards made to pass with the liquor through the bot- 

 tom of a copper pan, provided with numerous small 

 holes or perforations, into a tub containing twelve 

 pounds and a half of fat oil ; and in this the oil and 

 dung are, by sufficient stirring, to be well mixed with 

 the ley, and with each other ; and in this mixture, 

 which contains but half the quantity of oil prescril>od 

 by M. Papillon, the cotton (lOOlbs.) is to be steeped, &c. 

 as directed by the latter. It ig highly important after 

 this, and each of the succeeding oj>eratioi!s, that the 

 cotton should be thoroughly and completely dried, by 

 a stove heat; that of the OJH-II ;iir, in this climate, not 

 being sufficient, even in summer." 



This part of the process is precisely the same with 

 the last in every particular, except that the sheep's 

 dung is omitted in the composition of the >teep. 



Remark by Dr Bancroft. " At Rouen, this steep if 

 prepared by mixing thirty-eight gallons of ley of soda 

 with ten pounds of olive oil, and stirring them until 

 the mixture become* uniformly milky ; which it will 

 do without much difficulty, and remain so without any 

 separation of the oil, if the quality of the latter l>e 

 suited to this use ; this they add to what may have 

 been left of the former >tivn, and after mixing them 

 properly, they impregnate the cotton therewith by the 

 usual treatment; drying it after an interval of twelve 

 hours, firt in the open air, and afterwards by a stove 

 heat. This steeping and subsequent drying must be 

 repeated once, twice, or three times, according to cir- 

 cumstances, to be mentioned hereafter. 



Between this while steep, and the following fall steep, 

 it is the practice at Rouen to employ three salt steeps, 

 and one cleansing operation. In the first, (called pre- 

 mier tel,) twenty-tour gallons of the ley of soda, mark- 

 ing two and a half degrees, are mixed in a tub, with the 

 remnant of the white steep ; and with this the cotton 

 is impregnated, and dried an in the former operations. 

 In the nt-xt, (called second tel,) the remnant of the last 

 steep is mixed with twenty-tour gallons of the ley of 

 oda, marking three degrees, and the cotton steeped 

 therein, and dried as before. In the third, (called Iroi- 

 tifxie sel,) tl>e remnant of the preceding steep is mixed 

 with twenty-four gallons of the ley of soda, marking 

 three and a half degrees ; and with this the cotton is to 

 be impregnated, and dried as before. The residuum of 



this steep, called sikiou, is preserved, to be used in the Procewcs of 

 brightening operation. v Dyeing.^ 



In the cleansing operation, (called degraisxage,) the ^ v 

 cotton is steeped one hour in lukewarm water, then 

 wrung by the hands, and afterwards washed in a stream 

 of water, to remove any superfluous oruncombined oil, 

 which, as is supposed, might obstruct the equal appli- 

 cation and uniform effect of the following gall steep, 

 and thereby render the colour when dyed unequal. Af- 

 ter being so washed, the cotton is to be dried, first in 

 the open air, and afterwards by a stove heat." 



Boil twenty-five pounds of galls, bruised, in ten pails step 4*. 

 of river water, until four or five are boiled away ; strain Gall steer*, 

 the liquor into a tub, and pour cold water on the galls 

 in the strainer, to wash out of them all their tincture. 

 As soon as the liquor is become milk- warm, dip the cot- 

 ton into it hank by hank, handling it carefully all the 

 time, and let it steep twenty-four hours ; then wring it 

 carefully and equally, and dry it well without wash- 

 ing. 



Remark by Dr Bancroft: " This constitutes the 

 eighth operation at Rouen, where, as well as in M. Pa- 

 pillon 's process, galls in sorts seem to be now employed, 

 though it was formerly thought by the dyers of Turkey 

 red, (as several of them assured me, ) that only the white 

 galls, or those from which, at maturity, the insects had 

 made their escape, were fit for this purpose ; the others 

 In-ing supposed to give an injurious brown stain to the 

 cotton. But probably it has been since found, that this 

 stain is removed without any trouble by the subsequent 

 brightening operation. At Rouen, the cotton, as soon 

 as it has sufficiently imbibed the soluble part of the 

 galls, and been very moderately wrung, is spread as 

 expeditiously as possible in the open air, if the weather 

 be dry, or if not, under cover ; but the drying is al- 

 ways finished by a stove heat. 



Dissolve twenty-five pounds of Roman alum in four- Step 5th. 

 teen pails of warm water, without making it boil ; skim Vmt alum 

 the liquor well, and add two pails of strong barilla wa- stee P' 

 ter, and then let it cool until it be lukewarm. Dip 

 your cotton, and handle it hank by hank, and let it 

 Kteep twenty-four hours ; wring it equally, and dry it 

 well without washing. 



Remark by Dr Bancroft : " At Rouen, thirty or 

 thirty-five pounds of the purest alum are commonly em- 

 ployed for this steep, with only seven pails of hot wa- 

 ter ; adding, when the alum has been dissolved, two 

 gallons only of the lixivium, or ley of soda, marking 

 i'our degrees. But when these proportions are employ- 

 ed, the cotton is not subjected to a second steep with 

 alum, as directed in M. Papillon's sixth step. Some- 

 times, however, at Rouen, two steeps, with the alumi- 

 nous mordants, are employed ; and, in that case, twen- 

 ty pounds of alum are dissolved for the first, and fifteen 

 pounds for the second, leaving an interval of two days 

 between them, during which the cotton should retain 

 its moisture, after being slightly wrung from the first 

 steep. It is, however, to be well dried before it goes 

 into the second. 



" This steep is performed in every particular like the g^p gj,. 

 last ; but when the cotton is dry, steep it six hours in Second 

 the river, and then wash and dry it again. alum steep. 



" The cotton is dyed in parcels of about ten pounds step 7th. 

 at once ; tor which take about two gallons and a half of Dyeing 

 ox blood, and mix it in the copper, with twenty-eight steep. 

 l>:iils of milk-warm water, which arc to be well stirred; 

 then add twenty-five pounds of madder, and stir the 

 whole well together. Then having before hand put 

 the ten pounds of cotton on sticks, dip into the liquor. 



