or Deprimens,** in anatomy, a name applied to several muscles, because they depress the parts they are fastened to.

**DEPRIVATION,** in the canon-law, the deposing a bishop, parson, vicar, &c. from his office and pre-ferment.

**DEPTFORD,** a town three miles east of London, on the southern banks of the Thames; chiefly considerable for its fine docks for building ships, and the king's yard. E. Long. o. 4. N. Lat. 51. 30.

**DEPTH,** the measure of any thing from the surface downwards.

*Measuring of Depths by the Barometer,* depends on the same principles on which heights are measured by the same instrument. The mensuration of depths, being chiefly applied to mines, is still more precarious than the mensuration of heights, on account of the various kinds of vapours with which these subterranean regions are filled. But for a particular account of these difficulties, with the best methods of obviating them, see the articles **Barometer** and **Mines.**

**Depth of a Squadron, or Battalion,** is the number of men in a file; which in a squadron is three, and in a battalion generally six. See **Squadron, File,** &c.

We say, the battalion was drawn up five deep; the enemies horse were drawn up five deep.

**DEPURATION** is the freeing of any fluid from its heterogeneous matter or feculence. It is of three kinds. 1. Decantation; which is performed by letting the liquid to be depurated stand for some time in a pretty deep vessel, till the gross sediment has fallen to the bottom; after which the clear fluid is poured off. 2. Despumation; which is performed by means of the whites of eggs, or other viscid matter, and is also called **clarification.** 3. Filtration. See **Chemistry,** no. 69.

**DEPURATORY FEVER,** a name given by Sydenham to a fever which prevailed much in the years 1661, 1662, 1663, and 1664. He called it depuratory, because he supposed that nature regulated all the symptoms in such a manner, as to fit the febrile matter, prepared by proper concoction, for expulsion in a certain time, either by a copious sweat, or a freer perspiration.

**DEPUTATION,** a mission of select persons out of a company or body, to a prince or assembly, to treat of matters in their name.

**DEPUTY,** a person sent upon some business, by some community.

**Deputy** is also one that exercises an office in another's right; and the forfeiture or misdemeanor of such deputy shall cause the person whom he represents to lose his office.

**DEPUTATUS,** among the ancients, a name applied to persons employed in making of armour; and likewise to brisk active people, whose business was to take care of the wounded in engagements, and carry them off the field.

**DERBEND,** a strong town of Asia, in Persia, said to have been founded by Alexander the Great. The walls are built with stones as hard as marble; and near it are the remains of a wall which reached from the Caspian to the Black sea. It is seated near the Caspian sea, at the foot of Mount Caucasus. E. Long. 50. o. N. Lat. 42. 8.

**DERBY,** the capital of a county of the same name in England. It is thought to have received its name from being formerly a park or shelter for deer; and what makes this supposition more probable is, that the arms of the town consist of a buck couchant in a park. It is very ancient, having been a royal borough in the time of Edward the Confessor. At present it is a neat town, very populous, and sends two members to parliament. In digging for foundations of houses, human bones of a monstrous size have sometimes been found. The trade consists in wool, corn, malt, and ale, of which considerable quantities are sent to London. Here also is that curious machine for throwing silk, the model of which Sir Thomas Lombe, at the hazard of his life, brought from Italy. Before that time, the English merchants used to purchase thrown silks of the Italians for ready money. But by the help of this wonderful machine, one hand-mill will twist as much silk as 50 people could do without it. It works 73,726 yards of silk every time the water-wheel goes round, which is thrice in a minute. The house in which it is contained, is five or six stories high, and half a quarter of a mile in length. When Sir Thomas's patent expired in 1732, the parliament was so sensible of the value and importance of the machine, that they granted him a further recompence of £4,000l. for the hazard and expense he had incurred in introducing and erecting it, upon condition he should allow an exact model of it to be taken. This model is deposited in the Tower of London, in order to prevent so curious and important an art from being lost.—The town of Derby is watered by a river and a brook; the latter of which has nine bridges over it, the former only one. W. Long. i. 45. N. Lat. 52. 57.

**DERBY-SHIRE,** a county of England, bounded on the east by Nottinghamshire, and a part of Leicestershire, which last bounds it also on the south. On the west it is bounded by Staffordshire, and part of Cheshire; and on the north by Yorkshire. It is near 40 miles in length from south to north; about 30 in breadth on the north side, but on the south no more than five.—The air is pleasant and healthful, especially on the east side; but on the west, about the peak, it is sharper and more subject to wind and rain. The soil is very different in different parts of the country. In the east and south parts it is very fruitful in all kinds of grain; but, in the west, beyond the Derwent, it is barren and mountainous, producing nothing but a little oats. There is, however, plenty of grass in the valleys, which affords pasture to a great number of sheep. This part of the county is called the Peak, from a Saxon word signifying an eminence. Its mountains are very bleak, high, and barren; but extremely profitable to the inhabitants. They yield great quantities. ties of the best lead, antimony, iron, scythe-stones, grind-stones, marble, alabaster, a coarse sort of crystal, azure, spar, and pit-coal. In these mountains are two remarkable caverns, named Poole's Hole, and Elden-Hole; for a description of which, see these articles.