Prepamiwii of Soap from Alkali and V.'col. 41 



faturation. The pvoducl is a foft foap, very foluble in water, of a green greyifli colour, 

 ■well blended (blcn lie)', and pofleffing an animal fmell, which the cloths lofe by wafliing and 

 expofure to the air. 



The various experiments I have made on this fubje£l have prefented the following refults: 



1. As foon as the wool is plunged in the boiling liquid, the filaments adhere together, 

 and a flight agitation is fufficicnt to effect the complete fulution. 



2. The lye becomes coloured, and gradually thickens', iu proportion as more wool is added. 



3. The foap is more or lefs coloured accordingly as the wool is lefs or more clean and 

 white. 



4. The pile or hairs which are mixed with the wool are more difficult of folution. 



5. The quantity of wool the alkali is capable of dilToK ing, depends upon the ftrength of the 

 lixivium, its caufticity, and the degree of heat. Two pounds three ounces and fix drams of 

 caullic alkali, at twelve degrees * of concentration, and at the boiling heat, dilTolved ten 

 ounces four drams of wool. The foap, when cooled, weighed one pound four ounces. 



An equal quantity of alkali, at the fame degree of caufticity, heat and concentration, in 

 which I dilTolved four ounces of wool, did not acquire confiftence fufficlent to anfwer feveral 

 of the purpofes required. 



An equal quantity of alkali, marking four degrees, diflblved only two ounces feven drams of 

 wool. The foap, when cooled, weighed fourteen ounces. It was of a good confiftence. 



6. In proportion as the wool is diflblved in the lixivium, the folvent power of the alkali 

 decreafes, and at laft it takes up no more. It is at this period, nam^^ly, when the wool being 

 agitated in the fluid is no longer diflblved, that the operation muft be terminated. 



I. The Choice and Preparation of Materials. 



The materials required to form this foap are two, alkaline matters and wool. 



The alkaline fubftances may be obtained from the alhes of common culinary fires -f-, and 

 the lye made by the well-known procefles. Lime is to be flaked with a fmall quantity of 

 water; the parte is to be mixed with fifted wood-afhes, in the proportion of one-tenth part of 

 quicklime compared with the weight of the aflies. The mixture is to be put into a fmall ftone 

 trough (for wooden veflels colour the lye, and become fpeedily ufelefs) ; water is to be poured 

 on to the depth of feveral inches. After a certain time, the folution may be drawn ofl"at an 

 aperture formed in the bottom of the veflel for that purpofe. It muft not be drawn off" but 

 at the moment previous to its ufe, and may have the ftrength from four to P.fteen degrees. 

 But, indeed, it is of little confequence what the ftrength may be, becnufe the only difl'erence 

 rcfultiiig from the ufe of a weak or a ftrong lye is, that the quantities of wool which are 

 diflblved, will difler accordingly. 



The potafli of commerce may be employed in the fame manner, by mixiiig_ one-third of its 

 weight of quicklime. 



As to the choice of the wool, every one knows, that in the manufa£lories of woollen cloths of 



"■ Qu. By what mearure ? — It is greatly to be wilTied that all meafurcs derived from the dcnfiiy of fluids were 

 reduced to the common cxpreflion of the tables wherein water is taken as unity or i.ooo. N. 



+ Wood being much more ufually burned in France than iu England, their common aflics art what in London 

 are obtained only from the bakers. The uninftrudtcd workman fliould be aware that coal-aflics are unfit for 

 iliii p'ir|iofe. 



Vol.]. — April 1797. G every 



