An EJpty on Bleaching, 303 



flaked lime fifted, and 1 6 gallons of water. When the whole 

 is well mixed, it niuft be kept in a (late of ebullition for half 

 an hour, flrongly itirring it feveral times. When the ebul- 

 lition fubfides, the folution of the fulphuret becomes clear : 

 the liquor may be drawn off from the infoluble depofit by 

 means of a fyphon *. The liquor will have the colour almoft 

 of fmall beer, but is not quite fo tranfparent. 



Sixteen gallons of water mud ftill be poured over the de- 

 pofit, to take away entirely the remaining fulphuret. When 

 the liquor becomes clear, (it muft firft be well fhaken,) it is 

 drawn off and mixed with the former : to this mixture of the 

 two liquors 33 gallons of water are to be added, in order te» 

 reduce it to the degree of ftrength neceffary for the immerfion 

 of cloth. 



Making allowance for the water evaporated, and for that 

 retained by the precipitate, there ought to remain 60 gallons 

 of liquor produced by the four pounds of fulphur. 



The cloth freed from the weaver's drefling muft then be 

 immerfed for twelve or thirteen hours in the folution of ful- 

 phuret, and be then rinfed in running water. When dry, 

 it is immerfed for twelve or fourteen hours in a folution of 

 oxygenated muriate of lime prepared as I have defcribed, and 

 it muft then be waftied and dried as before. The operation 

 muft be repeated fix different times; that is to fay, there 

 muft be fix immerfions in each liquor, which will be fuffi- 

 cient for bleaching it completely. Cloths boiled fix times in, 

 a ley of potafti, and immerfed as many times in oxygenated 

 muriatic acid, were not whiter than thofe bleached by the 

 new method. 



The cloth, indeed, after the three firft times it was boiled 

 in the ley of potafh, feemed a little whiter than thofe im- 

 merfed as many times in the fulphuret : but towards the end 

 of the operation, when the cloth was completely bleached, 

 the advantage was in favour of the fulphuret, or, at leaft, the 

 difference was not fenfible. The cloths whitened by potafti 

 feemed more meagre than thofe which had been treated by 

 the fulphuret, and fupported the proof of being boiled with 

 foap better than others 3 though the latter had acquired in 

 fome inftances a flight yellowith (hade, which, however, dif- 

 appeared after fix or feven days expofure on the grafs. 



An experiment has been tried on the effect of fulphuret 

 cold and warm, but the difference was fo little that it did 



* Though lime is one of the condiment parts of the fulphnret, as it i« 

 intimately united to fulphur, it has no longer the properties of iime. fcr 

 the fame reafen that the f«;pkioic acid in the / tybatc of fiotajb h fc $ no 

 longer the properties w: .;;*t acid, 



not 



