Dry a towel in the sun, weigh it carefully, and note its weight. Then
dip it into sea-water, wring it sufficiently to prevent its dripping,
and weigh it again; the increase of the weight being that of the water
imbibed by the cloth. It should then be thoroughly dried, and once more
weighed; and the excess of this weight above the original weight of the
cloth shows the quantity of the salt retained by it; then, by comparing
the weight of this salt with that of the sea-water imbibed by the
cloth, we shall find what proportion of salt was contained in the water.