The name hemimorphite was given by G. A. Kenngott in 1853 because of the typical hemimorphic development of the crystals. The mineral had long been confused with calamine (q.v.) and even now this name is often applied to it. On account of its pyroelectric properties, it was called electric calamine by J. Smithson in 1803.
Hemimorphite occurs with other ores of zinc (calamine and blende), forming veins and beds in sedimentary limestones. British localities are Matlock, Alston, Mendip Hills and Leadhills; at Roughten Gill, Caldbeck Fells, Cumberland, it occurs as mammillated incrustations of a sky-blue colour. Well-crystallized specimens have been found in the zinc mines at Altenberg near Aachen in Rhenish Prussia, Nerchinsk mining district in Siberia, and Elkhorn in Montana.
(L. J. S.)
HEMINGBURGH, WALTER OF, also commonly, but erroneously, called Walter Hemingford, a Latin chronicler of the 14th century, was a canon regular of the Austin priory of Gisburn in Yorkshire. Hence he is sometimes known as Walter of Gisburn (Walterus Gisburnensis). Bale seems to have been the first to give him the name by which he became more commonly known. His chronicle embraces the period of English history from the Conquest (1066) to the nineteenth year of Edward III., with the exception of the years 1316-1326. It ends with the title of a chapter in which it was proposed to describe the battle of Creçy (1346); but the chronicler seems to have died before the required information reached him. There is, however, some controversy as to whether the later portions which are lacking in some of the MSS. are by him. In compiling the first part, Hemingburgh apparently used the histories of Eadmer, Hoveden, Henry of Huntingdon, and William of Newburgh; but the reigns of the three Edwards are original, composed from personal observation and information. There are several manuscripts of the history extant—the best perhaps being that presented to the College of Arms by the earl of Arundel. The work is correct and judicious, and written in a pleasing style. One of its special features is the preservation in its pages of copies of the great charters, and Hemingburgh’s versions have more than once supplied deficiencies and cleared up obscurities in copies from other sources.
The first three books were published by Thomas Gale in 1687, in his Historiae Anglicanae scriptores quinque, and the remainder by Thomas Hearne in 1731. The first portion was again published in 1848 by the English Historical Society, under the title Chronicon Walteri de Hemingburgh, vulgo Hemingford nuncupati, de gestis regum Angliae, edited by H. C. Hamilton.
HEMIPTERA (Gr. ἡμι-, half and πτερόν, a wing), the name applied in zoological classification to that order of the class Hexapoda (q.v.) which includes bugs, cicads, aphids and scale-insects. The name was first used by Linnaeus (1735), who derived it from the half-coriaceous and half-membranous condition of the forewing in many members of the order. But the wings vary considerably in different families, and the most distinctive feature is the structure of the jaws, which form a beak-like organ with stylets adapted for piercing and sucking. Hence the name Rhyngota (or Rhynchota), proposed by J. C. Fabricius (1775), is used by many writers in preference to Hemiptera.
| After Marlatt, Bull. 14 (N.S.) Div. Ent. U.S. Dept. Agr. |
| Fig. 1.—Head and Prothorax of Cicad from side. |
| I., Frons. II., Base of mandible. III., Base of first maxillae. IV., Second maxillae forming rostrum. V., Pronotum. |
Structure.—The head varies greatly in shape, and the feelers have usually but few segments—often only four or five. The arrangement of the jaws is remarkably constant throughout the order, if we exclude from it the lice (Anoplura). Taking as our type the head of a cicad, we find a jointed rostrum or beak (figs. 1 and 2, IV. b, c) with a deep groove on its anterior face; this organ is formed by the second pair of maxillae and corresponds therefore to the labium or “lower lip” of biting insects. Within the groove of the rostrum two pairs of slender piercers—often barbed at the tip—work to and fro. One of these pairs (fig. 2, II. a, b, c) represents the mandibles, the other (fig. 2, III. a, b, c) the first maxillae. The piercing portions of the latter—representing their inner lobes or laciniae—lie median to the mandibular piercers in the natural position of the organs. These homologies of the hemipterous jaws were determined by J. C. Savigny in 1816, and though disputed by various subsequent writers, they have been lately confirmed by the embryological researches of R. Heymons (1899). Vestigial palps have been described in various species of Hemiptera, but the true nature of these structures is doubtful. In front of the rostrum and the piercers lies the pointed flexible labrum and within its base a small hypopharynx (fig. 2, IV. d) consisting of paired conical processes which lie dorsal to the “syringe” of the salivary glands. This latter organ injects a secretion into the plant or animal tissue from which the insect is sucking. The point of the rostrum is pressed against the surface to be pierced; then the stylets come into play and the fluid food is believed to pass into the mouth by capillary attraction.