not the percentage in the soil but the
percentage in the soil water that counts. A farmer with his potash
locked up in silicates is like the merchant who has left the key of his
safe at home in his other trousers. He may be solvent, but he cannot
meet a sight draft. It is only solvent potash that passes current.

In the days of our grandfathers we had not only national independence
but household independence. Every homestead had its own potash plant and
soap factory. The frugal housewife dumped the maple wood ashes of the
fireplace into a hollow log set up on end in the backyard. Water poured
over the ashes leached out the lye, which drained into a bucket beneath.
This gave her a solution of pearl ash or potassium carbonate whose
concentration she tested with an egg as a hydrometer. In the meantime
she had been saving up all the waste grease from the frying pan and pork
rinds from the plate and by trying out these she got her soap fat. Then
on a day set apart for this disagreeable process in chemical technology
she boiled the fat and the lye together and got "soft soap," or as the
chemist would call it, potassium stearate. If she wanted hard soap she
"salted it out" with brine. The sodium stearate being less soluble was
precipitated to the top and cooled into a solid cake that could be cut
into bars by pack thread. But the frugal housewife threw away in the
waste water what we now consider the most valuable ingredients, the
potash and the glycerin.

But the old lye-leach is only to be found in ruins on an abandoned farm
and we no longer burn wood at the rate of a log a night. In 1916 even
under the stimulus of tenfold prices the amount of potash produced as
pearl ash was only 412 tons--and we need 300,000 tons in some form. It
would, of course, be very desirable as a conservation measure if all the
sawdust and waste wood were utilized by charring it in retorts. The gas
makes a handy fuel. The tar washed from the gas contains a lot of
valuable products. And potash can be leached out of the charcoal or from
its ashes whenever it is burned. But this at best would not go far
toward solving the problem of our national supply.

There are other potash-bearing wastes that might be utilized. The cement
mills which use feldspar in combination with limestone give off a potash
dust, very much to the annoyance of their neighbors. This can be
collected by running the furnace clouds into large settling chambers or
long flues, where