Per cent.
Carbonate of potash 86.78
Chloride of potassium 6.18
Sulphate of potash 2.83
Silica, alumina, etc. 4.21
------
100.00

In 1859, MM. Maumene and Rogelet patented the use of the water in
which wool has been washed as a source of potash, and at present the
extraction of potash from _suint_ is practiced in France on a large
scale. The wool is washed in a systematic manner, in casks, with cold
water, which runs out of the last cask with specific gravity 1.1. These
washings are evaporated to dryness, and the residue is calcined in iron
retorts, the gas evolved being used for illuminating purposes. The
remaining cinder, consisting of a mixture of charcoal and carbonate of
potash, is treated with water, whereby the latter is dissolved out.
The residue left on evaporation of this water consists largely--almost
entirely--of white carbonate of potash. At present there are works at
Rheims, Elboeuf, Fourmier, and Vervier, which yield about 1,000 tons of
carbonate of potash annually. Now, only 15,000 tons are made per annum
by Leblanc's process. In 1868, 62,000 tons of wool were imported into
Britain from Australia alone, and from this 7,000 to 8,000 tons of
carbonate of potash might have been recovered, the value of which is
L260,000. Yet it was all wasted! And this estimate does not include the
fats of the _suint_, which are worth an even greater sum.

Now, it is evident that there is here a profitable source of economy. So
far as I am aware, no work in this country saves its washings. The water
all goes to pollute the nearest river.