The soda carbonate may also be added to soap as a solution of soda ash (58° alkali) either concentrated, 62° tw.
This is made as follows: a soda ash liquor of about 15° to 20° tw.
After five minutes the wood is washed, and grained with acetate of iron (the ordinary iron liquor of the dyer) at 20° tw.
The souring is done by passing the goods through an acid liquor at 2° tw.
The most important material, however, is the caustic potash lye which should average 40° tw.
The cotton is first steeped in a bath of acetate of lead of about 10° tw.
Why, lad, 'tw'u'd be like throwin' yer silver into the sea to spend it on them good-fur-nothin', shif'less critters.
Tallow and palm oil require lye of a density of 15° to 18° tw.
(20° B.), when the calcium sulphate is allowed to deposit, and the separated liquor concentrated to 48° tw.
A slight addition of a weak solution of pearl ash, 4°-8° tw.