32 1 New Method af Bleaching 



which in this case may or may not be previously impregnated 

 uitli an alkahne, soapy, or other lye. 



If soot be the substance employed to furnish the volatile 

 alkali, a lye nnist be prepared from it by lixiviation with 

 water. For this purpose, a cask or other vessel shou}d be 

 provided with a double bottom, the upper one perforated 

 with a number of small holes, and the space between the 

 two filled with straw, or with any material which will lie 

 open enough to allow the lixivium to percolate, and yet close 

 enough to prevent the soot from passing with the clear liquor, 

 such straw or other material being intended merely to perform 

 the office of a filter. Into this cask or other vessel the socc 

 is to be. introduced above the double bottom, and water is to 

 be thrown upon it, in which it should be allowed to remain 

 for some hours ; after which the water may be drawn off by 

 a hole in the side close to the lower bottom of the cask or 

 other vessel aforesaid, and will be found to have extracted a 

 considerable quantity of volatile alkali from the soot, and to 

 have become an alkaline lye, which, after being rendered 

 caustic by the addition of about one pound of quick-lime to 

 every eight pounds of the lye, may then be conveyed to the 

 steaming-kettle, and applied to the purpose of bleaching, 

 whitening, and purifying in the manner before directed re- 

 specting the lye prepared with stale urine and quicklime ; or 

 it may, before being rendered caustic, be again put upon a 

 second and a third quantity of soot, and made to pass through 

 them as at first to render it more alkaline, and being then 

 rendered caustic by quicklime, as before directed, may be 

 applied to the purpose aforesaid. 



. Where such simple and cheap materials as urine or soot 

 cannot be procured in sufficient quantity, other substances 

 "inay be employed for the production of the volatile alkali, or 

 for extracting it from j or the common volatile alkali of com- 

 merce mav be employed with the steaniiug-kcttlc, steaming- 

 vat, and other apparatus before described, and which may be 

 varied in form, shape, and arrangement, to answer the site 

 and other circumstances connected with particular buildings. 



The method of employing volatile alkali that has been spe- 

 cified will in every ca?:e be found to be more advantageous 



til an 



