Cut into eight half quarters a quartern loaf, two days old; it must be
neither newer nor staler. With one of these pieces, after having blown
off all the dust from the paper to be cleaned, by the means of a good
pair of bellows, begin at the top of the room, and, holding the crust
in the hand, wipe lightly downward with the crumb, about half a yard
at each stroke, till the upper part of the hangings is completely
cleaned all round. Then go round again, with the like sweeping stroke
downwards, always commencing each successive course a little higher
than the upper stroke had extended, till the bottom be finished. This
operation, if carefully performed, will frequently make very old paper
look almost equal to new. Great care must be taken not to rub the
paper hard, nor to attempt cleaning it the cross or horizontal way.
The surface of the bread, too, must be always cut away as soon as it
becomes dirty, and the pieces renewed as often as may be necessary.