liquoring. Strong soda ash solution with a firm soap will result in a
brittle product, whereas the texture of a weak soap would be greatly
improved by such addition.

A slight addition of a weak solution of pearl ash, 4 deg.-8 deg. Tw. (2.7-5.4 deg.
B.), improves the appearance of many soaps intended for household
purposes.

For yellow soaps, containing a low percentage of fatty acids, solutions
of silicate of soda of varying strengths are generally used.

It is always advisable to have a test sample made with the soap to
ascertain what proportion and what strength of sodium silicate solution
is best suited for the grade of soap it is desired to produce. It is
important that the soap to be "silicated" should be distinctly alkaline
(_i.e._, have a distinct caustic taste), or the resultant soap is liable
to become like stone with age. The alkaline silicate of soda (140 deg. Tw.,
59.5 deg. B.) is the quality most convenient for yellow soaps; this may be
diluted to the desired gravity by boiling with water. For a reduction of
3-4 per cent. fatty acids content, a solution of 6 deg. Tw. (4 deg. B.)
(boiling) is most suitable, and if the reduction desired is greater, the
density of the silicate solution should be increased; for example, to
effect a reduction of 20 per cent. fatty acids content, a solution of
18 deg. Tw. (12 deg. B.) (boiling) would probably be found to answer.

In some instances 140 deg. Tw. (59.5 deg. B.) silicate may be added; experiment
alone will demonstrate the amount which can be satisfactorily
incorporated without the soap becoming "open," but 1/10 of the quantity
of soap taken is practically a limit, and it will be found that the
temperature should be low; the same quantity of silicate at different
temperatures does not produce the same result. Various other strengths
of sodium silicate are employed, depending upon the composition and body
of the soap base--neutral silicate 75 deg. Tw. (39.4 deg. B.) also finds favour
with some soap-makers. Mixtures of soda crystals or soda ash solution
with silicate of soda solution are used for a certain grade of soap,
which is crutched until smooth and stiff. Glauber's salt (sodium
sulphate) produces a good smooth surface when added to soap, but, owing
to its tendency to effloresce more quickly than soda carbonate, it is
not so much used as formerly.

Common salt sometimes forms an ingredient in liquoring mixtures.
Potassium chloride and potassium silicate fin