On Bleaching. 37 



piece, and which should always be proportioned to the 

 thickness of the cloth, iuul, as before mentioned, to the 

 quantity of colouring matter to be dissolved. 



Those who u.se the bleaching liquor, either early or late 

 in the process, should immerse or steep the cloth iu it after 

 it had been boiled and washed, but never to put the cloth 

 from the field into it, as they will find, as I have done, that 

 tlie quality will be destroyed. 



I have likewise found that cloth, either linen or cotton, 

 neither stiffens with the eallender or beetling, if dried after 

 being only washed out of the bleaching liquor; it must 

 therefore be boiled in water or ashes: if the latter, it ought 

 to be put on the grass for a fiew days previous to finishino-; 

 and I advise the linen bleachers to give at least one boil m 

 ashes after the last bleaching liquor, not only to prevent the 

 cloth being soft or slack after finishing, but as the best 

 means of preventing mildews (so much complained of) by 

 the attraction of moisture. 



If any further proof was necessary to confirm what has 

 been before staled relative to the utility of early souring, it 

 will every day be found in the process of dipping or dveing 

 china blue, which is performed by alternate immersion in a 

 .solution of lime or ashes and sulphate of iron (copperas), 

 by which the iron is precipitated on the cloth; it is easily 

 removed by immediate souring : but if the cloth is exposed 

 for some tnne to the air, the iron cannot be dissolved with- 

 out injury to the texture or fibres, and the colour. 



I therefore entreat the bleachers of linen, calico, or 

 nmslin, will tn,' the effects of souring after the first boil, in 

 the manner before mentioned; and"" after the second boil 

 that they will pursue such process as ihcy have most im- 

 proved on (either bleaching on the field entirely, or the al- 

 ternate process of bleaching on the field after a few boils, 

 and then using the bleaching liquor with lime or ashes, in 

 their receivers) : this will most effectually enable them to 

 compare the relative progress, &c., and which will be veiy 

 obvious in favour f)f early souring. 



In a conversation a lew days ago with Mr. Whiteman, 

 of Li^burn, on the subjeel of Gleacliintr, he told me that his 

 inuslins had the buff" appearance I hacT described, not only 

 in the process of bleaching, but that he had then some un- 

 saleable, even at a loss of 10 per cent., in consequence of 

 that buff' or nuiddy appearance, a specimen of which he 

 gave me, and in whieli a considerable quantity of prussiate 

 of iron has been found. 



The muslins, calicoes, and linens, bought in the white for 



printing at my works, are generally stained and bad whites 



C 3 after 



