Plough, American, compared with French, vii, 190.
Plumbagine, a new vegetable substance, xvii, 385.
Plumbago formed by pressure, xlix, 227.
—, see [Graphite.]
Plumbago floridana, v, 290.
Plumbocalcite, new mineral species, xxvi, 386.
Plummer, J. T., miscellaneous observations on insects, xl, 146.
—, motion of particles of melted spermaceti of a burning candle, xl, 148.
—, suburban geology, (Indiana) xliv, 281.f
—, fucoids in Indiana, xliv, 290.f