south of the Nomos Thinites, on the west side of the Diospolites Nile.

DIOSPYROS, the INDIAN DATE PLUM; a genus of plants belonging to the polygamia class; and in the natural method ranking under the 18th order, Bicornes. See BOTANY Index.

DIPHTHONG, in Grammar, a double vowel, or the mixture of two vowels pronounced together, so as to make one syllable.

DIOSCOREA, a genus of plants belonging to the Dioscorea 1 diœcia class ; and in the natural method ranking under Diospolites. the 11th order, Sarmentacea. See BOTANY Index. The only remarkable and useful species is the bulbifera or yam. The roots of it are eaten by the inhabitants of both the Indies; and are particularly serviceable in the West India islands, where they make the greatest part of the negroes food. The plant is supposed to have been brought from the East to the West Indies; for it has never been observed to grow wild in any part of America; but in the island of Ceylon, and on the coast of Malabar, it grows in the woods, and there are in those places a great variety of sorts. It is propagated by cutting the root in pieces, observing to preserve an eye in each, as is practised in planting potatoes. One plant will produce three or four large roots. The skin of these roots is pretty thick, rough, unequal, covered with many stringy fibres or filaments, and of a violet colour approaching to black. The inside is white, and of the consistence of red beet. It resembles the potato in its mealiness, but is of a closer texture. When raw, the yams are viscous and clammy; when roasted or boiled, they afford very nourishing food; and are of ten preferred to bread by the inhabitants of the West Indies, on account of their lightness and facility of digestion. When first dug out of the ground, the roots are placed in the sun to dry; after which they are either put into sand, dry garrets, or casks; where, if kept from moisture, they may be preserved whole years, without being spoiled or diminished in their goodness. The root commonly weighs two or three pounds; though some yams have been found upwards of 20 pounds weight.

DIOSCORIDES, a physician of Cilicia, who lived, as some suppose, in the age of Nero. He was originally a soldier; but afterwards he applied himself to study, and wrote a book upon medicinal herbs.

DIOSCURIA (dioxovgia; from Asos, Jupiter, and zavęs, infants), in antiquity, a festival in honour of the Aloxovgo, or Castor and Pollux, who were reputed to be the sons of Jupiter. It was observed by the Cyre. neans, but more especially by the Spartans, whose country was honoured by the birth of these heroes. The solemnity was full of mirth, being a time wherein they shared plentifully of the gifts of Bacchus, and diverted themselves with sports, of which wrestling matches always made a part.

DIOSMA, AFRICAN SPIRÆA, a genus of plants belonging to the pentandria class; and in the natural method ranking with those of which the order is doubt ful. See BOTANY Index.

DIOSPOLIS, in Ancient Geography, a city of the Delta, or Lower Egypt; to the south of the Busiritic branch, before it divides into two.-Another of Bithynia, in the territory of Heraclea.-A third, called Magna, denoting Thebee of the Higher Egypt. A fourth, Diospolis Parva, the metropolis of the Nomos Diospolites of the Higher Egypt.-A fifth Diospolis, of Samaria, the same with Lydda.-A sixth Diospolis, the ancient name of Laodicea of Phrygia, on the Lycus.

DIOSPOLITES NOMOS, (Ptolemy,) a division of Thebais or the Higher Egypt, to distinguish it from another of the Lower Egypt or the Delta; to the

The Latins pronounced the two vowels in their diphthongs ae or æ, oe or œ, much as we do; only that the one was heard much weaker than the other, though the division was made with all the delicacy imaginable. Diphthongs, with regard to the eyes, are distinguished from those with regard to the ears in the former either the particular sound of each vowel is heard in the pronunciation; or the sound of one of them is drowned; or lastly, a new sound, different from either, results from both; the first of these only are real diphthongs, as being such both to the eye and ear. Diphthongs with regard to the ear are either formed of two vowels meeting in the same syllable, or whose sounds are severally heard; or of three vowels in the same syllable, which only afford two sounds in the pronunciation.

English diphthongs, with regard to the eye and ear, are ai, au, ea, ce, ei, oo, ou. Improper English diphthongs, with regard to the eye only, are aa, ae, eo, cu, ie, ei, oe, ue, ui.

DIPLOE, in Anatomy, the soft meditullium, or medullary substance which lies between the two laminæ of the bones of the cranium. See ANATOMY Index.

DIPLOMA. See DIPLOMATICS.

In a peculiar sense, it is used for an instrument or license given by colleges, societies, &c. to a clergyman to exercise the ministerial function, or to a physician to practise the profession, &c. after passing examination, or admitting him to a degree.

Diplomatics.

DIPLOMATICS, the science of diplomas, or of Bielfield. ancient literary monuments, public documents, &c. It Elements. does not, however, nor can it, absolutely extend its researches to antiquity; but is chiefly confined to the middle age, and the first centuries of modern times. For though the ancients were accustomed to reduce their contracts and treaties into writing; yet they graved them on tables, or covered them over with wax, or brass, copper, stone, or wood, &c. And all that in the first ages were not traced on brass or marble, has perished by the length of time, and the number of destructive events.

1. The word diploma signifies properly a letter or epistle, that is folded in the middle, and that is not open. But, in more modern times, the title has been given to all ancient epistles, letters, literary monuments, and public documents, and to all those pieces of writing which the ancients called Syngraphia Chirographa, Codicilli, &c. In the middle age, and in the diplomas themselves, these writings are called Litteræ, Præcepta, Placita, Chartæ indiculæ, Sagilla, and Bullæ; as also Pancharta, Pantocharte, Tractoriæ, Descriptiones, &c. The originals of these pieces are named Examplaria, or Autographa, Charte authenticæ, Originalia, &c. and the copies, Apographa, Copia, Particula, and so Ii2

forth.

Diploma- forth. The collections that have been made of them tics. are called Chartaria and Chartulia. The place where these papers and documents were kept, the ancients named Scrinia, Tabularium, or Ærarium, words that were derived from the tables of brass, and, according to the Greek idiom, Archeium or Archivum.

2. In order to understand the nature of these ancient papers, diplomas, and manuscripts, and to distinguish the authentic from the counterfeit, it is necessary to know that the paper of the ancients came from Egypt, and was formed of thin leaves or membranes, taken from the branches of a tree named Papyrus, or Biblum Egyptiacum, and which were pasted one over the other with the slime of the Nile, and were pressed and polished with a pumice stone. This paper was very scarce; and it was of various qualities, forms, and prices, which they distinguished by the name of charta hieratica, luria, augusta, amphitheatrica, suitica, tanirica, emporeti ca, &c. They cut this paper into square leaves, which they pasted one to the other, in order to make rolls of them from whence an entire book was called volumen, from volvendo; and the leaves of which it consisted, pagina. Sometimes, also, they pasted the leaves all together by one of their extremities, as is now practised in binding; by this method they formed the back of a book, and these the learned called codices. They rolled the volume round a stick, which they named umbilicus; and the two ends that came out beyond the paper, cornua. The title, wrote on parchment, in purple characters, was joined to the last sheet, and served it as a cover. They made use of all sorts of strings or ribbands, and even sometimes of locks, to close the book; and sometimes also it was put into a case. But there is not now to be found, in any library or cabinet whatever, any one of these volumes. We have been assured, however, by a traveller, that he had seen several of them in the ruins of Herculaneum ; but so damaged, the paper so stiff and brittle, by the length of time, that it was impossible to unrol them, and consequently to make use of any of them; for on the first touch they fell into shatters.

3. We are ignorant of the precise time when our modern paper was invented; and when they began to make use of pens in writing, instead of the stalks of reeds. The ink that the ancients used, was not made of vitriol and galls, like the modern, but of 300t. Some times also they wrote with red ink made of vermilion; or in letters of gold, on purple or violet parchment. It is not difficult for those who apply themselves to this study, to distinguish the parchment of the ancients from that of the moderns, as well as their ink and various exterior characters: but that which best distinguishes the original from the counterfeit is, the writing or character itself; which is so distinctly different from one century to another, that we may tell with certainty, within about 40 or 50 years, when any diploma was written. There are two works which furnish the clearest lights on this matter, and which may serve as sure guides in the judgments we may have occasion to make on what are called ancient diplomas. The one is the celebrated treatise on the Diplomatic, by F. Mabillon; and the other, the first volume of the Chronicon Gotvicense. We there find specimens of all the characters, the flourishes, and different methods of writing, of every age. For these matters, therefore, we

must refer our readers to those authors; and shall here Diplomaonly add, that,

4. All the diplomas are written in Latin, and consequently the letters and characters have a resemblance to each other: but there are certain strokes of the pen which distinguish not only the ages, but also the different nations; as the writings of the Lombards, French, Saxons, &c. The letters in the diplomas are also usually longer, and not so strong as those of manuscripts. There has been also introduced a kind of court hand, of a very disproportionate length, and the letters of which are called Exiles litteræ crispa, ac protractiores. The first line of the diploma, the signature of the sovereign, that of the chancellor, notary, &c. are usually wrote in this character.

They sometimes also added the dates and epoch of the signature, the feasts of the church, the days of the kalendar, and other like matters. The successive corruption of the Latin language, the style and orthography of each age, as well as their different titles and forms; the abbreviations, accentuation, and punctuation, and the various methods of writing the diphthongs; all these matters united, form so many characters and marks by which the authenticity of a diploma is to be known.

6. The seal annexed to a diploma was anciently of white wax, and artfully imprinted on the parchment itself. It was afterwards pendant from the paper, and inclosed in a box or case, which they called bulla. There are some also that are stamped on metal, and even on pure gold. When a diploma bears all the characters that are requisite to the time and place where it is supposed to be written, its authenticity is not to be doubted: but at the same time we cannot examine them too scrupulously, seeing that the monks and priests of former ages have been very adroit in making of counterfeits, and the more as they enjoyed the confidence of princes and statesmen, and were even sometimes in possession of their rings or seals.

7. With regard to manuscripts that were wrote before the invention of printing, it is necessary (1.) to know their nature, their essential qualities, and matter; (2.) to be able to read them freely, and without error; (3.) to judge of their antiquity by those characters which we have just mentioned with regard to the diplomas; and (4.) to render them of use in the sciences. As there are scarce any of the ancient codes now remaining (see par. 2.), wrote on the Egyptian paper, or on wood, ivory, &c. we have only to consider those that are written on parchment or vellum (membraneos); and such as are wrote on our paper (chartaccos). The

former

ties.

ties

Diploma former of these are in most esteem. With regard to the character, these codes are written either in square and capital letters, or in half square, or round and small Dipping letters. Those of the first kind are the most ancient. There are no intervals between the words, no letters different from the others at the beginning of any word, no points, nor any other distinction. The codes which are wrote in letters that are half square, resemble those we have in Gothic characters, as well for the age as the form of the letters. Such as are wrote in round letters are not so ancient as the former, and do not go higher than the ninth or tenth century. These have spaces between the words, and some punctuation. They are likewise not so well wrote as the preceding, and are frequently disfigured with comments. The codes are divided, according to the country, into Lombard, Italian, Gaulic, Franco-Gaulic, Saxon, Anglo-Saxon, &c.

8. In the ancient Greek books, they frequently terminated the periods of a discourse, instead of all other division, by lines; and these divisions were called, in Latin, versus, from vertendo: for which reason these lines are still more properly named versus than lineæ. At the end of a work, they put down the number of verses of which it consisted, that the copies might be more easily collated and it is in this sense we are to understand Trebonius, when he says, that the Pandects contain 150,000 pæne versuum. These codes were like wise vel proba vel deterioris notæ, more or less perfect, not only with regard to the calligraphy or beauty of the character, but to the correction of the text also.

9. It is likewise necessary to observe, in ancient codes, the abbreviations, as they have been used in different centuries. Thus, for example, A. C. D. signifies Aulus Caius Decimus; Ap. Cn. Appius Cneius; Aug. Imp. Augustus Imperator. The characters that are called note, are such as are not to be found in the alphabet; but which, notwithstanding, signify certain words. All these matters are explained in a copious manner by Vossius, and in the Chronicon Gotvicense. Lastly, The learned divide all the ancient codes into codices minus raros, rariores, editos, et anecdotos. The critical art is here indispensably necessary: its researches, moreover, have no bounds; and the more, as the use of it augments every day, by the discoveries that are made in languages, and by the increase of erudition.

DIPONDIUS, in the scripture language, is used by St Luke to signify a certain coin which was of very little value. Our translation of the passage is, " Are not two sparrows sold for two farthings ?" In St Matthew, who relates the same thing, we read “Are not two sparrows sold for a farthing ?" The Greek reads assarion instead of as. Now assarion, as some say, was worth half an as, that is to say, four French deniers and th; and, according to others, two deniers and ths. Dipondius seems rather to signify half an as. Calmet, Diction. Bibl. Luke xii. 6. Matt. x. 29.

Dr Arbuthnot differs in opinion from the author last quoted. He says, that this coin was at first libralis, or of a pound weight; and even when diminished, it retained the name of libella. So that dipondius denotes

two asses.

DIPPING, among miners, signifies the interrup tion or breaking off the veins of ore; an accident that

gives them a great deal of trouble before they can dis- Dipping, cover the ore again. A great deal of the skill of the Dipping miners consists in the understanding this dipping of the Needle. veins, and knowing how to manage in it. In Cornwall they have this general rule to guide them in this respect: most of their tin-loads, which run from east to west, constantly dip towards the north. Sometimes they underlie; that is, they slope down towards the north three feet in height perpendicular. This must carefully be observed by the miners, that they may exactly know where to make their air-shafts when occasion requires; yet, in the higher mountains of Dartmaer, there are some considerable loads, which run north and south; these always underlie toward the east. Four or five loads may run nearly parallel to each other in the same hill; and yet, which is rare, they may meet altogether in one hatch, as it were a knot, which well tins the place, and so separate again, and keep their former distances.

DIPPING Needle, an instrument used for observing the quantity of inclination towards the earth, assumed by any needle or other body after it has acquired the magnetic virtue. This was first observed by one Robert Norman, an Englishman, and maker of compasses for mariners, in the end of the 16th century; who finding that he was always obliged to counterbalance that end which turns to the north by a bit of wax or such other substance, though the balance had been ever so exact before, published an account of his discovery as a matter of importance. The subject was instantly attended to; and instruments were not only contrived for ascertaining the quantity of the dip, but various speculations formed concerning the cause of such a surprising phenomenon.

The general phenomena of the dipping needle are: that about the equatorial parts of the earth it remains in a horizontal position, but depresses one end as we recede from these; the north end, if we go towards the north, and the south end if we proceed towards the south pole. The farther north or south that we go, the inclination becomes the greater; but there is no place of the globe hitherto discovered where it points directly downwards, though it is supposed that it would do so in some part very near the pole. Its inclination is likewise found to vary very considerably at different times in different places of the earth, and by some changes of situation, in such a manner as must appear at first sight very unaccountable. Of all those who have attempted the investigation of this obscure subject, none have been more successful than M. Cavallo, who in his Treatise on Magnetism has given particular attention to all the phenomena, and accounted for them upon plain and rational principles, in the following

manner :

The dip of the magnetical needle in general may be understood from the following easy experiment:Lay an oblong magnet horizontally upon a table, and over it suspend another smaller magnet (a sewing needle to which the magnetic virtue has been communicated will answer the purpose), in such a manner as to remain in a horizontal position when not disturbed by another magnet. Now, if this last small magnet or sewing needle, suspended by the middle, be brought just over the middle of the large one, it will turn itself in such a manner that the south pole of the small mag