70 Method of making 
gree of agitation is sufficient to render its solution coin* 
plete. 
2. In proportion as fresh wool is added, the ley gra- 
dually acquires colour and consistence. 
3. The soap has more or less colour, in proportion to 
the cleanness and whiteness of the wool made use of. 
4. Hair of a coarser kind, which happens to be mixed 
with the old wool, is dissolved with more difficulty. 
5. The quantity of wool which the ley is capable of 
dissolving depends upon its strength, its causticity, and 
its degree of heat. Two pounds, three ounces and three 
quarters, of caustic alkaline ley, at twelve degrees of 
concentration, and at the boiling heat, dissolved ten ounces 
and a half of wool. The soap, when cold, weighed one 
pound four ounces. 
A similar quantity of alkaline ley, of the same degree 
of causticity anti heat, in which I dissolved four ounces 
of wool, did not thereby acquire sufficient consistence to 
be capable of being used for the various purposes for 
which this soap is intended. 
An oilier similar quantity of ley, of four degrees of com 
centration, could not dissolve more than two ounces and 
seven drams of wool. The soap was of a good consist- 
ence, and, when cold, weighed fourteen ounces. 
<5. In proportion as the wool is dissolved in the ley, 
the solvent power of the alkali grows weak, and at last it 
will dissolve no more. When we observe that the wool, 
upon being stirred in the liquor, is no longer dissolved, it 
is then time to stop the process. 
I shall now point out what means are to he employed, 
in every woollen manufactory, to prepare the soap which 
will be wanted in it 
