rch, which are left to dry a little, and
are then broken into smaller pieces, and left on the plaster-floor, till
very dry. But if the weather is at all humid, the starch is removed from
the plaster-floor and spread out upon shelves, in an apartment which is
warmed by a stove, and there it remains till perfectly dry. The pieces
are afterwards scraped, to remove the outside crust, which makes common
starch; and the scraped pieces being again broken small, the starch is
carried to the stove, and spread out to a depth of three inches, on
hurdles covered with cloths. The starch must be turned over every
morning and evening, to prevent it from turning to a greenish colour,
which it would otherwise do. Those manufacturers who are not provided
with a stove, make use of the top of a baker's oven to spread the starch
upon; and after being thoroughly dried here, it is ready for sale.
Starch may be made from potatoes, by soaking them about an hour in
water, and taking off their roots and fibres, then rubbing them quite
clean by a strong brush: after this they are reduced to a pulp, by
grating them in water. This pulp is to be collected in a tub, and mixed
up with a large quantity of clear water: at the same time, another clean
tub must be provided; and a hair sieve, not too fine, must be supported
over it by two wooden rails extended across the tub. The pulp and water
are thrown into the sieve, and the flour of starch is carried through
with the water; fresh water must then be poured on, till it runs through
quite clear. The refuse pulp which remains in the sieve, being boiled in
water, makes an excellent food for animals; and the quantity of this
pulp is near seven-eighths of all the potatoes employed. The liquor
which has passed through the sieve is turbid, and of a darkish colour,
from the extractive matter which is dissolved in it. When it is suffered
to rest for five or six hours, all this matter deposits or settles to
the bottom, and the liquor which remains is to be poured off as useless;
and a large quantity of fresh water is thrown upon the flour, and
stirred up: it is then settled for a day, and the water being poured
off, the flour will be found to have again settled in a whiter state.
But to improve it, another quantity of water is poured on, and mixed up
with it; in which state it is passed through a fine silk sieve, to
arrest any small quantity of the pulp which may have escaped the first
hair sieve. The whole must aft