— in the Kenawha valley, xxix, 121.
— in the valley of the Sandy river, Virginia, xxix, 129.
— or oil spring of Allegany Co., N. Y., xxiii, 97.
—, well of, near Burksville, Ky., xxxix, 195.
Pettengill, A., on floating islands, xii, 122.
—, stellarota of, xvi, 363.
Pettenkoffer, M., test for bile, xlix, 206.
Peucedanum ternatum, xxviii, 165.
Pfaff, theory of voltaic electricity, xix, 178.
Phacelia, species of, xlv, 171, 172.