HYDESPARK, a township of Vermont, in Orleans county, 126 miles N. by E. of Bennington.. HYDNUM, in botany: A genus of the natural order of fungi, belonging to the cryptogamia clafs of plants. The fungus is echinated or prickly on the under fide. One of the fpecies, viz.

HYDNUM IMBRICATUM, is a native of Britain, and is found in woods. It has a convex hat, tiled, ftanding on a smooth pillar, of a pale flesh colour, with white prickles. It is eaten in Italy, and is faid to be of a very delicate taste.

(1.)* HYDRA. n. f. [hydra, Lat.] A monster with many heads flain by Hercules: whence any multiplicity of evils is termed a hydraNew rebellions raife

Their hydra heads, and the falfe north displays Her broken league to imp her ferpent wings. Milton.

ed first at Cambridge, and afterwards at Oxford. Before he was 18 years of age, he was fent from Cambridge to London to affist Mr. Brian Walton in the great work of the Polyglot Bible; and about that period undertook to tranfcribe the Perfian Pentateuch out of the Hebrew characters, which Abp. Usher, who well knew the difficulty of the undertaking, pronounced to be an impoffible task to a native Perfian. After he had happily fucceeded in this, he affifted in correcting feve. ral parts of Mr Walton's work, for which he was perfectly qualified. He was made archdeacon of Gloucefter, canon of Chrift-church, head-keeper of the Bodleian library, and profeffor of Hebrew and Arabic, in the univerfity of Oxford. He was interpreter and fecretary of the Oriental languages, during the reigns of Charles II. James II. and William III.; and was perfectly qualified to fill his post, as he could converse in all these languages. There never was an Englishman in his Situation of life who made fo great a progrefs; but his mind was fo engroffed by his beloved ftudies, that he did not appear to advantage in common conversation. Of all his learned works (the very catalogue of which, as obferved by Anth. Wood, is a curiofity), his Religio Veterum Perfarum is the most celebrated. Dr. Gregory Sharpe, the late learned and ingenious mafter of the Temple, has collected feveral of his pieces formerly printed, and republished them, with fome additional differtations, and his life prefixed, in two elegant vols. 4to. He died on the 18th Feb. 1702. Among his other works are, 1. A Latin tranflation of Ulug Beig's obfervations on the longitude and latitude of the fixed ftars; and, 2. A catalogue of the printed books in the Bodleian library.

(4.) HYDE, a maritime county of N. Carolina, in Newbern diftri&t; bounded on the E. by the Atlantic, S. by Carteret, W. by Beaufort, and N. by Tyrrel counties. It contained, 3072 citi zens and 1048. flaves in 1795.

(5.-7.) HYDE, 3 English villages, in Berkshire, Dorfetfhire, and Warwickshire..

HYDERALY, or ALL, a famous Indian ufurper, and for fome time a formidable opponent of the British intereft in the Eaft Indies. He was the fon of a killader, or governor of a fort, to the king of Myfore, and acquired his fkill in military tactics in the French army. In 1753, he diftinguished hiinfelf as their auxiliary at Trichinopoly. In 1763, being commander of the Myfore army, he dethroned his fovereign, and governed the kingdom under the title of regent. In the wars with the British between 1767 and 1770, he difplayed great fpirit and abilities; but in 1771 he was totally defeated by the Mahrattahs. During the peace that followed he greatly improved his army and revenues. In 1780, he made an irruption into the Carnatic, and cut to pieces a British detachment under Col. Baillie; but his victorious career was loon, ftopt by Sir Eyre Coote, who, with a force fcarce exceeding 7cco men, gained a complete victory over Ilyder Ali at the head of 150,000, and defeated bim 6 times fucceflively afterwards, the laft of which victorics was obtained on the 7th June 1782. Hyder died in Dec. 1782, Eve months before Gen. Coote.

Dryden.

(2.) HYDRA, in fabulous hiftory, was a ferpent in the marsh of Lerna, in Peloponnefus, with many heads, one of which being cut off, another, or two others, immediately fucceeded in its place, unlefs the wound was inftantly cauterized., Hercules attacked this monfter; and having caufed Iolaus to hew down wood for flaming brands, as he cut off the the heads he applied the brands to the wounds, by which means he deftroyed the Hydra. This Hydra is supposed to have been a multitude of ferpents which infefted the marshes of Lerna near Mycene, and feemed to multiply as they were deftroyed. Hercules, with the affiftance of his companions, cleared the country of them, by burning the reeds in which they lodged.

(3.) HYDRA, in astronomy, a fouthern conftellation, confifting of a number of ftars, imagined to reprefent a water ferpent. See ASTRONOMY, $48.

(4.) HYDRA, in geography, an island in the Grecian Archipelago. Lon. 43. 25. E. of Ferro. Lat. 37. 15. N.

(5.) HYDRA, in zoology, a genus of the order of zoophyta, belonging to the clafs of vermes. There are feveral fpecies, known by the general name of polypes. See ANIMALCULE, $5,8; and POLYPUS, N° II.

(1.) HYDRABAD, a province of Hindooftan, now called GOLCONDA, which fee.

(2.) HYDRABAD, the capital of Golconda and of the Deccan, a large city, feated in a plain, on the banks of a river that runs into the Kiftna. It is furrounded with walls, and defended with towers; and contains above 100,000 inhabitants. It is 690 miles S. of Delhi, and 270 NNW. of Madras, according to Mr Cruttwell; but Dr Brookes and J. Walker make it 352 miles N. by E. of that city. Lon. 78. 52. E. Lat 17. 17. N.

(3.) HYDRABAD, a fort of Hindooftan Proper, in the province of Sindy, the refidence of a Mahometan prince, who is tributary to the king of Candahar. It is fituate op the Indus, near Nufferpour. Lon. 69. 30. E. Lat. 25. 29. N.

HYDRENTEROCELE, în furgery, a fpecies of hernia, wherein the inteftines defcend into the fcrotum, together with a quantity of water.

(1.) * HYDRAGOGUES. n. ƒ. [¿dwę and ayw; bydragogue, Fr. Such medicines as occafion the difcharge of watery humours, which is generally the cafe of the ftronger catharticks, because they make most forcibly the bowels and their appendages. Quincy.

(2.) HYDRAGOGUES, [from idag, water, and ayv, to draw,] are used in dropfies; but the original ufe of the term proceeded upon a mistaken fup. pofition, that every purgative had some particular humour which it would evacuate, and which could not be evacuated by any other. It is now, however, discovered, that all ftrong purgatives will prove bydragogues, if given in large quantity, or in weak conftitutions. The principal medicines, recommended as hydragogues, are the juice of elder, the roots of iris, foldannella, mechoacan, jalap, &c.

HYDRANGEA, in botany, a genus of the digynia order, belonging to the decandria clafs of plants; and in the natural method ranking under the 13th order, Succulenta. The capsule is bilocular, biroftrated, and cut round, or parting horizontally. There is but one species, viz.

HYDRANGEA ARBORESCENS, a native of North America, from whence it has lately been brought to Europe, and is preserved in gardens, more for the fake of variety than beauty. It rifes about 3 feet high; and has many foft pithy ftalks, garnifhed with two oblong heart-shaped leaves placed oppofite. The flowers are produced at the top of the stalks in a corymbus. They are white, composed of 5 petals with to ftamina furrounding the ftyle. Thefe plants are easily propagated by parting the roots, in the end of October. They thrive beft in a moist foil, but must be fheltered

from froft.

HYDRARGYRUM, mercury, or 'quickfilver; fo called from Jag, water, and agyupos, filver; q.d. water of filver, on account of its refembling liquid or melted filver.

HYDRASTIS, in botany, a genus of the polygamia order, belonging to the polyandria clafs of plants, and in the natural method ranking with thofe of which the order is doubtful. There is neither calyx nor nectarium; there are 3 petals; and the berry is compofed of monofper

mous acini.

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* HYDRAULICAL. adj.[from hydraulick.] (1.) * HYDRAULICK. Relating to the conveyance of water through pipes.-Among the engines in which the air is useful, pumps may be accounted, and other hydraulical engines. Derham. -We have employed a virtuofo to make an bydraulick engine, in which a chymical liquor, refembling blood, is driven through elaftick channels. Arbuthnot and Pope.

(2.) HYDRAULICKS, n. f. [idwg, water, and ava, a pipe.] The fcience of conveying water through pipes or conduits.

(3.) HYDRAULICS comprehend the science of the motion of fluids, and the conftruction of all kinds of inftruments and machines relating thereto. See HYDROSTATICS, Part II.

HYDRAULICO-PNEUMATICAL, adj. a term applied to engines, which raife water by means of See HYDROSTATICS, Part II. Se&. VII. X.

air.

(1.) HYDRIA, or IDRIA, a town of Germany in Carniola, 9 miles SSW. of Crainburg, and 154 of Vienna.

(2.) HYDRIA, a river of Carniola, which rifes near Gewelb, and runs paft the town of HYDRIA (N° 1.), into the Lifonzo.

(1.) HYDROCELE. n. f. [i♪poxnan; hydrocel, Fr.] A watery rupture.

(2.) HYDROCELE, in furgery, denotes any her. nia arifing from water; but is particularly used for fuch a one of the fcrotum, which fometimes grows to the fize of one's head, without pain, but exceedingly troublefome. See SURGERY, Index

(1.)* HYDROCEPHALUS, n. f. [dwg and xpan. A dropfy in the head.-A bydrocephalus, of dropfy of the head, is only incurable when the ferum is extravafated into the ventricles of the brain. Arbuthnot on Diet:

(2.) HYDROCEPHALUS is a preternatural distenfion of the head to an uncommon fize, by a ftagnation and extravafation of the lymph; which, when collected in the infide of the cranium, is then termed internal; as that collected on the outfide is termed external. See MEDICINE, Index.

HYDROCHARIS, the LITTLE WATER LILLY, a genus of the enneandria order, belonging to the diccia clafs of plants; and in the natural method ranking under the first order, Palma. The spatha of the male is diphyllous; the calyx trifid; the corolla tripetalous; the three inferior filaments ftyliferous. The female calyx trifid; the corolla tripetalous; the ftyles fix; the capfule has 6 cells, and is polyfpermous inferior. There is only one fpecies, a native of Britain, growing in flow ftreams and wet ditches. It has kidney-fhaped leaves, thick, fmooth, and of a brownish green colour with white bloffoms. There is a variety with double flowers of a very fweet smell.

HYDROCOTYLE, WATER NAVELWORT, a genus of the digynia order, belonging to the pen. tandria clafs of plants; and in the natural method ranking under the 45th order, Umbellata. The umbel is fimple; the involucrum tetraphyllous; the petals entire; the feeds are half round and compreffed. There are feveral species, none of which are ever cultivated in gardens. One of them, a native of Britain, growing in marthy grounds, is fuppofed by the farmers to occafioa the rot in fheep. The leaves have central leafftalks, with about 5 flowers in a rundle; the peૐ tals are of a reddish white.

HYDROGENE GAS, or See CHEMISTRY, HYDROGENOUS GAS, Š Index. Citizen Lebon, an ingenious French chemift, has contrived a method of producing from hydrogene gas not only a very clear light, but a very strong heat.

J. Stewart s.