Parterre: A level division of ground, a flower-garden.

Pearlash: The common name for impure carbonate of potash, which in a purer form is called Saleratus.

Peristaltic: Contracting in successive circles; worm-like.

Petroleum: Rock oil, an inflammable, bituminous liquid exuding from rocks or from the earth in the neighborhood of the carboniferous or coal-bearing formation.

Phosphorous: One of the elementary substances.

Physician in Ordinary to the Queen: The physician who attends the Queen in ordinary cases of illness.

Pitt, William: A celebrated English statesman, son of the Earl of Chatham. He was born May 28th, 1759, and at the age of twenty-three was made Chancellor of the Exchequer, and soon afterward Prime Minister. He died January 23d, 1806.

Political Economy: The science which treats of the general causes affecting the production, distribution, and consumption of articles of exchangeable value, in reference to their effects upon national wealth and welfare.

Pollen: The fertilizing dust of flowers, produced by the stamens and falling upon the pistils in order to render a flower capable of producing fruit or seed.

Potter's clay: The clay used in making articles of pottery.