PROSERPINA, the daughter of Zeus and Demeter, who was carried off while gathering flowers by PLUTO (q. v.), became Queen of Hades, and is represented as sitting on an ebony throne beside him wearing a crown.  According to later tradition Pluto had to allow her to revisit the upper world for two-thirds of the year to compromise matters with her mother, her arrival being coincident with the beginning of spring and her return to Hades coincident with the beginning of winter.  She became by Pluto the mother of the Furies.

PROSPERO, one of the chief characters in Shakespeare’s “Tempest,” an exiled king of Milan, who, during his exile, practises magic, and breaks his wand when he has accomplished his purpose.

PROTAGORAS, one of the earliest of the Greek Sophists, born at Abdera, and who flourished in 440 B.C., and taught at Athens, from which he was banished as a blasphemer, as having called in question the existence of the gods; he taught that man was the measure of all things, of those that exist, that they are; and of those things that do not exist, that they are not; and that there is nothing absolute, that all is an affair of subjective conception.

PROTECTION, name given to the encouragement of certain home products of a country by imposing duties on foreign products of the class, opposed to free-trade.

PROTESTANTISM, the name given to a movement headed by Luther in the 16th century, in protestation of the supremacy in spiritual things claimed by the Church of Rome, and made on the ground of the authority of conscience enlightened by the Word of God, conceived of as the ultimate revelation of God to man.

PROTESTANTS, a name given to the adherents of Luther, who, at the second Diet of Spires in 1529, protested against the revocation of certain privileges granted at the first Diet in 1526.

PROTEUS, in the Greek mythology a divinity of the sea endowed with the gift of prophecy, but from whom it was difficult to extort the secrets of fate, as he immediately changed his shape when any one attempted to force him, for it was only in his proper form he could enunciate these secrets.

PROTOGENES, a Greek painter of the time of Alexander the Great, born in Caria; lived chiefly at Rhodes; was discovered by Apelles, who brought him into note; his masterpiece is a picture of Ialysus, the tutelary hero of Rhodes, on which he spent seven years, and which he painted four times over.

PROTOPLASM, a name given to presumed living matter forming the physical bases of all forms of animal and vegetable life; the term is now superseded by the term bioplasm.  See DR. STIRLING, “AS REGARDS PROTOPLASM.”