504 -An EJJhy on Bleaching. 



not deferve to be taken into confideration. Cloths immerfed 

 m the [ulphuretj and then boiled in a ley of potafh, and af- 

 terwards introduced into the oxygenated liquor, are whiter 

 than after they have been fubjec.ted to two immerfions in the 

 fulphttretj arid been made to pafs through the ley: thus the 

 two fu.b trances feemfcd defirous of co-operating. Two fuc- 

 eefTive imrrierfions, however, in the fuiphuret, before being 

 immerfed in the oxygenated liquor, produced a better effect 

 than one immerfion ; which is not the cafe with potafh. 



It is of importance to obferve, that fluffs are always and 

 invariably thicker and more fwelled up when they come from 

 the fuiphuret of lime than after they have been fubjecled to 

 the ley of potafh ; and they continue to retain thefe qualities 

 even after they have t>een wafhed, and dried on the grafs. 

 The fuiphuret opens the fibres of the cloth better and more 

 fpeedily than potafh, by foftening them, and rather by mak- 

 ing them fvvel! up> than by diffolving the extraclo-mucous or 

 colouring matter. This may ferve to explain why potafh 

 produces a better effeel: on cloth -when it has been before 

 immerfed in a folution of fuiphuret of lime. 



The proprietors of bleach -fields, who perfift in not making 

 ufe of the oxygenated muriatic acid, but who bleach in the 

 open air, may perhaps derive fome advantages from this pro- 

 cefs, if they ufe fuiphuret of lime and potafh either con- 

 joint!^ or feparately. The advantage and faving of expenfe 

 which refult from fuiphuret of lime are evident : for ten years 

 the price of foda and potafh has been executively dear, and 

 has always increafed. In all Europe, at prefent, the latter 

 article colls about 70 francs (about 2/. 18s.) per hundred 

 weight; and foda is nearly a third lefs. Sulphur may be 

 eftimated at 25 or 30 francs; on the other hand, lime, as it 

 is every where found, cofts very little; the price of this de- 

 terfive liquor, therefore, will become fo low that we have no 

 coin fm all enough to reprefent the value of a quart of it. The 

 truth of this fact will appear by a comparifon with the price 

 of common ley. 



At large bleach-fields the ley is made by diffolving four 

 pounds of potafh, or fix pounds of foda, in 6b gallons of 

 water : fome employ a little more : but four pounds of potafh 

 at jo cents, make two francs 80 cents., and a like quantity 

 of fulphur at 25 cents, makes one franc : but this is not all, 

 as there is a faving in fuel as well as of materials; no more 

 is required than the quantity neceffary for boiling eight gal- 

 lons of water, while the common ley requires that 64 fhorild 

 be brought to the ftate of ebullition. The time requifite for 

 heating this mafa of water prefents alio a faving which is 



far 



