ON THE YOLK OF WOOL. Q^ 



But if the wool be put into buckets, and only as much water 

 as will moiften it poured in, and it it be I'ufFered to remain 

 feme time in this bath, prefling it often, it fcouri much better, 

 and becomes much whiter afterwards, by walhing in running 

 water. 



The fcourers have a culiom of macerating the wool in pu- Putrid urine 



trefied urine, and it is generally believed that it is the ammo- ^°^^ ^?^ ^/°' 



* o J mote the Icoi!-- 



nia which is developed that effects the fcouring ; but I have ing. 



fome reafon to think that this alkali is of no value. This effe6l 

 is rather owing to the yolk itfelf, or to fome other principle of 

 the urine, to the uree, for example. The following are the 

 grounds of my opinion in this refpedt ; I put wool wafhed in 

 running water into a mixture of fal ammonia and common pot- 

 alh ; the mixture had a llrong fniell of ammonia, and never- 

 thelefs the wool was in no refpect cleanfed, becaufe ihis alkali 

 does not form, or at leafl with great difficulty, a faponaceous 

 combination with the greafy matter of wool. From tliefe ob- 

 fervations, therefore, I believe putrid urine to be nearly ufe- 

 lefs in the fcouring of wool, at leafl as far as refpetis its am- 

 monia. 



Though the utility of putrified urine be in fome degree doubt- Fieih urine 



ful, it is, on the contrary, very certain that frelh urine would be wouid precipi- 

 ■'*-', . . tate the greafe. 



greatly injurious to the propoied object, for the foap cqniained 



in ihe yoik would incontefltibly experience a decompolition by 



(he acid of the urine, which would precipitate the greafe on 



the wool. 



I fufpecl that the fame effect would take place from wafliing As would water 

 the wool in waler containing earthy falts, which are known containing 

 to decompofe alkaline foaps. For which reafon it is always 

 prudent to employ Ihe purefl water which can be procured 

 for this purpofe. 



This is not the cafe with foap-fuds, whicJi accomplifn the Soap-fuds the 

 fcouring of vv'.-ol perfedly, at the fame time giving it niore ^^^ '"'"^^'^""'"" 

 v>liilenc(s. l^, therefore, after having walhed the wool in 

 running water till it lofes no more, it be fufFered to macerate 

 tor a few hours in only one twentieth of its weight of foap dif- 

 lolved in a fufficient quantity of warm waler, fqueezing it 

 often, it will be entirely purged gf the fmall portion of greafe 

 which ftill adhered to it, and will then have a fofinefs and 

 degree of clearnefs which it could m)t have had without this 

 (Operation. 



The. 



