own. He belonged to the school of Benedict Oxenstjerna and was therefore an avowed advocate of a pacific policy. He protested in vain against nearly all the military ventures of Charles XII., e.g. the War of Deposition against Augustus of Saxony and Poland, the invasion of Saxony, the raid into the Ukraine. Again and again he insisted that the pacific overtures of Peter the Great should at least be fairly considered, but his master was always immovable. Piper's career came to an end at Poltava (1709), where he was among the prisoners. The last years of his life were spent in exile in Russia. He died at Schlüsselburg on the 29th of May 1716.
See W. L. Svedelius, Count Carl Piper (Stockholm, 1869). (R. N. B.)
PIPERAZIN, a substance formed by the action of sodium glycol on ethylene-diamine hydrochloride, consisting of small alkaline deliquescent crystals with a saline taste and soluble in water. It was originally introduced into medicine as a solvent for uric acid. When taken into the body the drug is partly oxidized and partly eliminated unchanged. Outside the body piperazin has a remarkable power of dissolving uric acid and producing a soluble urate, but in clinical experience it has not proved equally successful. Lycetol, lysidine and sidonal are bodies having similar action.
PIPERINE, C17H19NO3, an alkaloid found in the fruits of Piper nigrum and P. longum. It forms white prisms, which melt at 128°-219°. It is almost insoluble in water, but readily soluble in alcohol and ether. It is a very weak base, salts being only formed with mineral acids, and these are dissociated by water. Alcoholic potash decomposes it into piperidine, C5H11N, and piperic acid, C12H10O4. The constitution of piperic acid was elucidated by R. Fittig and his pupils (Ann., vols. 152, 159, 168, 216, 227) and shown to be (1). Piperine consequently is (2).
Oxidation with potassium permanganate converts piperic acid into pilperonal, C8H6O3, and piperonylic acid, C8H6O4. The latter when heated with hydrochloric acid to 170°, or water to 200°, separates carbon with the formation of protocatechuic acid, 1⋅2-dioxy-3-benzoic acid, C6H3(OH)2COOH. Conversely, by heating protocatechuic acid with potash and methylene iodide, piperonylic acid was regained. These results show that piperonylic acid is the methylene ether of protocatechuic acid. Piperonal (q.v.) is the corresponding aldehyde. Piperic acid differs from piperonylic acid by the group C4H4, and it was apparent that these carbon atoms must be attached to the carbon atom which appears in the carboxyl group of piperonylic acid, for if they were directly attached to the benzene ring polycarboxylic acids would result in oxidation. The above formula for piperic acid was confirmed by its synthesis by A. Ladenburg and M. Scholtz (Ber., 1894, 27, p. 2958) from piperonyl acrolein (the condensation product of piperonal and acetaldehyde) and acetic acid. The synthesis of piperine follows from the interaction of piperyl chloride (formed from piperic acid and phosphorus pentachloride) and piperidine (L. Rugheimer, Ber., 1882, 15, p. 1390).
PIPERNO (anc. Privernum), a town of the province of Rome, Italy, 61 m. S.E. of Rome by rail. Pop. (1901), 6736. The medieval town was founded in the 10th century (?) on a hill 490 ft above sea-level, by refugees from the Roman town of Privernum, lower down (118 ft. above sea-level) on the highroad, 1¼ m. to the north, at the mouth of a low pass leading through the Volscian mountains to the valley of the Sacco. Here are remains of an arch crossing the road and other ruins (mostly buried) of the Roman period; but the remains above ground are largely medieval. It is improbable, however, that the ancient Volscian town should have occupied so easily accessible a site, it is not unlikely that it stood on the site occupied by the medieval and modern town, but there is no proof of this. Privernum was a Volscian town, and took up arms against Rome after the foundation of a Latin colony at Setia in 382 B.C. It was finally captured in 329 B.C., and eleven years later the tribus Oufentina was founded, taking its name from the river Oufens (mod. Uffente) in the territory of Privernum. Little is known of it subsequently. The medieval town has a picturesque piazza, with a Gothic cathedral (1283), which preserves a fine porch, though the interior was modernized in 1782; a Gothic palazzo pubblico, and other Gothic churches exist in the town. Polygonal terrace walls of the Roman or pre-Roman period exist at various places in the vicinity (G. B. Giovenale and L. Mariani in Notizie degli Scavi, 1899, 88). (T. As.)
PIPERONAL (heliotropine, protocatechuic aldehyde methylene ether), C8H6O3, an aromatic aldehyde. It is prepared by oxidizing piperic acid with potassium permanganate (R. Fittig, Ann., 1869, 152, p. 35); by condensing methylene iodide with protocatechuic aldehyde (R. Wegscheider, Monats., 1893, 14, p. 388); or by oxidizing isosafrol with chromic acid. It forms long colourless crystals which melt at 37° C. and boil at 263° C. It has an agreeable smell, resembling that of heliotrope, and is much used in perfumery. It is only slightly soluble in cold water, but is readily soluble in alcohol and in ether. When heated with dilute hydrochloric acid to 200° C. it yields protocatechuic aldehyde, C7H6O3, and carbon. It readily combines with sodium bisulphite and with various bases (ammonia, aniline, methylamine, &c.).
PIPIT (cognate with Lat. Pipio; see Pigeon), the name applied by ornithologists to a group of birds having a great resemblance both in habits and appearance to the larks (q.v.). They differ from larks in several important characters, and, having been first separated to form the genus Anthus, which has since been much broken up, are now generally associated with the wagtails (q.v.) in the Passerine family Motacillidae. Pipits, of which over fifty species have been described, occur in almost all parts of the world, but in North America are represented by only two species—Neocorys spraguii, the prairie-lark of the north-western plains, and Anthus ludovicianus, the American titlark, which last is very nearly allied to the so-called water-pipit of Europe, A. spipoletta. To most English readers the best known species of pipit is the titlark or meadow-pipit, A. pratensis, a bird too common to need description, and abundant on pastures, moors, and uncultivated districts generally; but in some localities the tree-pipit, A. trivialis, or A. arboreus of some authors, takes its place, and where it does so it usually attracts attention by its loud song, which is not unlike that of a canary, but delivered (as appears to be the habit of all the pipits) on the wing and during a short circuitous flight. Another species, the rock-lark, A. obscurus, scarcely ever leaves the sea-coast, and is found almost all round the British Islands. The South-African genus Macronyx, remarkable for the extreme length of its hind claw, is generally placed among the pipits, but differs from all the rest in its brighter coloration, which has a curious resemblance to the American genus Sturnella (see Icterus), though the bird is certainly not allied thereto. (A. N.)
PIPPIN, or Pepin, the name of three members of the Carolingian family.
Pippin I. (d. 640), incorrectly called Pippin of Landen, was mayor of the palace to the youthful Dagobert I., whom Clotaire II had placed over the kingdom of Austrasia. He was disgraced when Dagobert became sole king in 629, and had to seek refuge in Aquitaine. Returning at Dagobert's death (639), he governed Austrasia in Sigebert's name, but died in the following year.
Pippin II. (d. 714), incorrectly called Pippin of Herstal, was son of Adalgiselus (son of Arnulf, bishop of Metz) by a daughter of Pippin I., called in later documents Begga. Towards 678 he placed himself at the head of the great nobles in Austrasia to combat Ebroïn, the mayor of the palace, and Neustria. After some reverses he gained a great victory after Ebroïn's death at the battle of Tertry, not far from St Quentin. This victory made Pippin almost entire master of Gaul. He appointed one of his sons mayor of the palace of Neustria, reserving for another of his sons the mayoralty of Austrasia. He made war
