Potosi silver mines, xxiv, 233.

Potstone, Middlefield, Mass., viii, 51.

— of Greenland, xvii, 14.

Potter, C. E., notice of a rocking stone, xxiv, 185.f

Pottery, analysis of, xv, 183.

—, notice of A. Brongniart on, xxxi, 134.

—, ancient American, xxvii, 175.

Powder of Cassius, purple, see [Cassius.]

— of Balda, viii, 204.

— mills, inflamed by the stroke of copper, xiii, 161.