Potamogeton Claytoni, xlv, 38.
— pulcher, xlv, 38.
Potassa in sea-water, iii, 371.
—, caustic, of commerce, xxxv, 299.
—, commercial, of New York, researches on, L. C. Beck, xxix, 260.
—, —, adulteration of, xxix, 261.
—, —, manufacture of, xxix, 261.
—, mode of obtaining from feldspar, Fuchs, xxi, 157.
—, detection of, by the oxide of nickel, xvi, 387.