PULTENEY PUMP 81 its typical form in the most profound state of dementia," as shown in the following sphyg- mographic tracing of the pulse of a patient 37 years of age. The trace given in fig. 5 shows a marked dicrotic form in a patient having slight symptoms of mania. This became ir- FIG. 5. Trace of Dicrotic Pulse in Mania. regularly tricrotic under excitement, and more regular after an outburst of excitement. Usually the pulsating movement of the blood is not continued into the capillary vessels ; but when the arteries are dilated in the glandular organs at the time of their increased func- tional activity, the pulsation is communicated to the capillaries, and even through them to the veins. This condition, however, lasts only during the period of increased vascular excite- ment ; and as it subsides, the movement of the blood in the capillaries again becomes uni- form, and the pulsation is limited as before to the arterial system. PULTENEY, William, earl of Bath, an English statesman, born in 1682, died in London, July 8, 1764. He was educated at Westminster school and at Christ Church, Oxford, travelled on the continent, and in 1705 became member of parliament for the borough of Hedon in Yorkshire. This position he owed to his guar- dian, Henry Guy, who subsequently left him a legacy of 40,000 and landed estate to the amount of 500 a year. He acted as a whig throughout the reign of Queen Anne, partici- pated in the prosecution of Sacheverell, and defended Walpole in the prosecution against him in 1712. When that minister resigned in 1717, Pulteney gave up his office of secretary at war, to which he had been appointed on the accession of George I. When Walpole resumed office in 1720, Pulteney was appointed coffer- er of the household ; but he went over to the opposition in 1725, was dismissed from his office, and became one of the most bitter ene- mies of the minister. He allied himself with Bolingbroke, and published pamphlets in which he attacked the ministry so virulently as to bring about a duel in 1731 between himself and Lord Hervey, in which both were slightly wounded. Through the brilliancy of his speech- es, and his patriotic sentiments, he became the most popular man in the nation ; and in 1742, when Walpole was driven from power, Pulte- ney constructed a new cabinet with the earl of Wilmington at its head, in which he took a seat, but without office, and accepted a peerage. The administration satisfied neither the people nor his partisans. Pulteney lost his popular- ity, and, as Chesterfield wrote, " shrunk into insignificance and an earldom." In 1746 the Pelham ministry resigned, and Pulteney became premier ; but he had so little influence that he was unable to obtain the assistance of any men of importance, and he held office only two days. In 1760 he published " A Letter to Two Great Men " (Pitt and the duke of Newcastle). As his only son had died before him, the peer- age in his family became extinct. PULTOCK, Robert, an English author, whose only known work is " The Life and Adventures of Peter Wilkins" (London, 1750), which de- scribes an imaginary race of flying islanders in the South Pacific. The name of the author was unknown till 1835, when, at a sale of books and manuscripts which had belonged to Dods- ley the publisher, the original agreement for the copyright tf the book was found, in which Pultock is described as " of Clement's Inn, gentleman." He sold his story for 20, with 12 copies of the work, and a set of the first impressions- of the engravings. PULTOWA. See POLTAVA. PUMA. See COUGUAR. PUMICE. See OBSIDIAN AND PTJMICE. PUMP, a machine for raising liquids in pipes, either by direct action or by atmospheric pres- sure, and also for exhausting air from vessels. (See AIR PUMP.) The history of the hydraulic pump cannot be clearly traced. Methods of raising water by wheels with buckets attached to their peripheries, and also by means of end- less ropes moved by two drum wheels, were used by the ancient Egyptians and Assyrians ; and the chain pump was probably derived from the Chinese, or at least was first used by them. But there is no evidence of the employment of a valve pump until near the commencement of the Christian era, although a machine re- sembling a portable pump is often represent- ed in' ancient Egyptian sculptures. "Vitruvius ascribes the invention of the valve pump to Ctesibius of Alexandria, who probably lived in the latter part of the 3d century B. C. The water pump of Ctesibius was described by Heron, who flourished in the same century. It consisted of two single-acting solid-headed pis- tons moving up and down in two vertical cylin- ders with lift valves at the bottom, and a branch pipe with an outgoing valve placed between the piston and the lower valve, and was very much like the simple force pump of the present day. The motive power in large machines was an undershot paddle wheel. The employment of a valve in the piston head, and placing this below the discharge pipe, so as to constitute a lift pump, was probably of later date. Ac- cording to the manner in which pumps act, they may be divided into vacuum and force pumps; but it is more common to divide them into the force pump, the common suction pump, the lift pump, and the suction and force pump combined. The power may be applied by a piston moving to and fro in a cylinder, or by a wheel revolving in a box. Rotary pumps, in which the latter method is used, may be simply force pumps or suction and force pumps, the power being applied by direct
