DIAGRYDIATES. n. f. [diagrydium, Ĺat.] Strong purgatives. made with diagrydium.—Alĺ cholerick humours ought to be evacuated by diagrydiates, mixed with tartar, or fome acid, or hubarb powder. Floyer.

DIAGRYDIUM. See DIACRYDIUM.

~ DIAH, DIAT, a name given by the Arabs to the punishment of retaliation. By the Mahometan law, a brother, or the next relation of a murdered perfon, ought to take part against the murderer, and demand his blood in reparation for the murder. Before the time of Mahomet, the Arabs had a custom of putting a freeman of their prison ers to death, in lieu of every flave they loft in battle, and a man for every woman that was killed. But Mahomet regulated the laws of reprisal; directing in the Alcoran, by the diat, that a freeman fhould be required for a freeman, and a flave for a flave. The Turks, probably in consequence of this law, formerly maffacred almost all their prifoners of war, but they now content themselves with enflaving and felling them. ?DIAHEXAPLA, among farriers, a comDIAHEXAPLE, pound medicine, fo called from its containing fix ingredients, viz. birthwort and gentian roots, juniper berries, bay berries, myrrh, and ivory thavings. It is commended for colds, confumptions, purfinefs, and many other -diforders in horses.

(1.)* DIAL.n.f.{diale, Skinner.] A plate marked with lines, where a hand or fhadow fhews the hour. O, gentlemen, the time of life is short: To spend that thortnefs bafely were too long, Though life did ride upon a dial's point, Still ending at th' arrival of an hour.

Shakespeare's Henry IV. If the motion de very flow, we perceive it not: we have no fenfe of the accretive motion of plants sor animals; and the fly fhadow fteals away upon the dial, and the quickest eye can discover no more than that it is gone. Glanville.

(2.) DIAL is derived from the Latin dies, day, because it indicates the hour of the day. The ancients alfo called it SCIATHERIUM, from its effe& by the fhadow. See DIALLING.

DIALACCA, in pharmacy, a medicine in which the chief ingredient is lacca.

= (1.) * DIALECT. n. S. [dix21x®.] 1. The fub divifion of a language; as the Attic, Doric, Ionic, olic dialects. 2. Style; manner of expreffion. When themselves do practife that whereof they write, they change their diale&; and those words they thun, as if there were in them fome fecret fting. Hooker. 3. Language; fpeech.

In her youth

There is a prone and speechlefs dialec,
Such as moves men. Shakesp. Meaf. for Measure.

(2.) DIALECT is an appellation given to the guage of a province, in fo far as it differs fro that of the whole kingdom. The term is partic larly used in speaking of the ancient Greek, when of there were 4 dialects; (fee § 1. def. 1.) each which was a perfect language in its kind, took place in certain countries, and had peculi beauties. In Great Britain, befides the 2 gra dialects of English and Scotch, almost every coun has a dialect of its own, all differing confiderab in pronunciation, accent, and tone, although and the fame language.

DIALECTICA. See DIALECTICS, § 2. (1.) * DIALECTICAL. adj. [from dialectic) Logical; argumental.-Those diale&ical subtles that the schoolmen employ about phyfiolog myfteries, more declare the wit of him that them, than increase the knowledge of sober log of truth. Boyle.

(2.) DIALECTICAL ARGUMENTS, such as barely probable, but do not convince. Be DIALECTICALLY, adv. in a dialectical ner. Ash.

(1.) * DIALECTICK. n. ƒ. [da2sx?xn.] Logi the act of reasoning.

(2.) DIALECTICs, in the literary hiftory of ancients, that branch of logic which taught rules and modes of reafoning. See Logic, I III. Zeno Eleates was the firft who difcove the natural series of principles and conclufiors ferved in reasoning, and formed an art thereof form of a dialogue; which, for this reafon, called dialectica.

(3.) DIALECTICS, ANCIENT. The dialectic the ancients is ufually divided into feveral kr J. The first was the eleatica, that of Zeno Elri which was threefold; viz. confecutionem, tionum, and contentionum: The firft confifter rules for deducing or drawing conclufions. fecond, the art of dialogue; which becam fach univerfal use in philofophy, that all real was called interrogation: then, fyllogifm being afide, the philofophers did all by dialogue: it on the refpondent to conclude and argue from feveral conceffions made. The laft part of Ze diale&ics, Egg, was contentious, or the ar difputing and contradicting; though fome, p cularly Laertius, afcribe this part to Protagor difciple of Zeno. II. The 2d is the dialectica garica, whofe author is Euclid, not the mathe tician, but another of Megara. He gave m into the method of Zeno and Protagoras; the there are two things appropriated to him: first, that he impugned the demonftrations thers, not by alumptions, but conclufions; tinually making illations, a proceeding from fequence to confequence: the fecond, that b afide all arguments drawn from comparif fimilitude as invalid. He was facceeded by bulides, from whom the fophiftic way of re ing is faid to be derived. In his time the a defcribed as manitold: mentiens, fallens, obvelată, arcevalis, cornuta, and calva. Sec

PHISM. III. The 3d is the dialectics of Plato, with he propofes as a kind of analysis to direct tekaman mind, by dividing, defining, and bringtags to the first truth; where being arrived, ed fopped there a little, it applies itfulf to exin ftatible things, but with a view to return to retrit truth where alone it can reft. Such is the a of Plato's analyfis. IV. The 4th is Aristotle's d; containing the doctrine of simple words, desvered in his book of Prædicaments; the docof propoutions, in his book De Interpretatione; that of the feveral kinds of fyllogifm, in his es of Analytics, Topics, and Elenchutes. V. The th is the diale&ics of the Stoics; which they a part of philofophy, and divide into rhetoric d dialectic; to which fome add the definitive, whereby things are juftly defined; comprehending wife the canons or criterions of truth. The s, before they treat of fyllogifms, have two pipal places; the one about the fignification ards, the other about the things fignified. Coccasion of the first, they confider abundance rags belonging to the grammarian's province: , and how many letters; what is a word, tion, tpeech, &c. On occafion of the latter, By confider things themselves, not as without the mind, but as in it, received in it by means of the fenfes. Accordingly, they first teach, that nil fit imdletu, quod non prius fuerit in sensu; "whatis in the mind came thither by the fenfes ;" md that aut incurfione fui, as Plato, who meets the bet; aut fimilitudine, as Cæfar by his effigy ; aut ptione, either by enlarging as a giant, or by Cathing as a pygmy; aut tranflatione, as a Cyt; aut compofitione, as a Centaur; aut contrais death; aut privatione, as a blind man. The 6th is Epicurus's diale&ics; for though beeems to have defpifed dialectic, he cultivated th vigour. He was only averfe to that of the ; who he thought attributed too much to is pronouncing him alone wife who was well eled in dialectics. For this reaton, Epicurus, ng to fet afide the common dialectics, had ure to another way; viz. to certain canons ich he fubftituted in their ftead, the collection ereuf he called canonica; and as all queftions pilofophy are either de re or de voce, he gave 44e rules for each. See EPICUREANS,

DIALEIMMA, among phyficians, the interval between the paroxyfins of a fever. Bailey. DIALEIPSIS, in furgery, the hollowness of wound: the space between.

DIALEXIS, [Aλķis, Gr.] a disputation. DIALIA, in antiquity, facrifices performed by the flamen dialis. See FLAMEN.

DIALING. See DIALLING.

(1.) DIALIS, in antiquity, a Latin term fignify ing something that belongs to Jupiter. The word is formed from As, the genetive of Zis, Jupiter, (2.) DIALIS FLAMEN, a prieft of Jupiter. See FLAMEN.

DIALIST. n. f. [from dial.] A conftructer of dials.-Scientifick "dialists, by the geometrick confiderations of lines, have found out rules ta mark out the irregular motion of the shadow in all latitudes, and on all planes. Moxon.

DIALITHA, in the writings of the ancients, a word used to exprefs the elegant ornaments of the Greeks and Romans, composed of gold and gems. They also called thefe LITHOCOLLA, q. d. cemented ftones or gems; the gold being in this cafe as a cement to hold the fiones toge ther. They wore bracelets and other ornamental things about their habits thus made; and their cups and table furniture, for magnificent treats were of the fame kind. The green ftones were found to fucceed beft of all in thefe things; and the emerald and greenish topaz, or as we call it, chryfolite, were moft in efteem for this purpose. This ufe of the ftones explains what Pliny very often says of them in his defcription: Nihil jucundius aurem decet, Nothing becomes gold better:' this he fays of the green topaz or chryfolite; and this and many other like paffages have greatly perplexed the critics, who did not hit upon this explication.

DIALIUM, in botany, a genus of the monogynia order belonging the diandria class of plants. The corolla is regular and pentapetalous; there is no calyx; the ftamina are at the upper fide of the receptacle.

DIALLAGE, Aλan, Gr.] in rhetoric, a figure, wherein many arguments are adduced, but none of them conclufive.

DIALLEL LINES, in geometry, fuch as run across or cut one another.

Alexander, and within 12 years of the building of Rome.

(4.) Among the ancients ANAXIMENES the Milefian, and THALES, are faid to have made dials, and Vitruvius mentions one made by the ancient Chaldee hiftorian BEROSUS, on a reclining plane almoft parallel to the equator.

(5.) ARISTARCHUS of Samos invented the hemifpherical dial, and there were at the fame time fome fpherical ones, with a needle for a gnomon. The difcus of Ariftarchus was an horizontal dial with its rim raifed up all around to prevent the fhadow from stretching too far. Gg 2

(6.) It

(6.) It was late before the Romans became acquainted with dials. The first fun dial at Rome was fet up by PAPIRIUS CURSOR, about A. U. C. 450; before which time rays Pliny there is no mention of any account of time but by the fun's Aing and fetting: it was fet up at or near the temple of Quirinus, but was very inaccurate. A bout 30 years after, M. Valerius Metiala being conful, brought out of Sicily another dial, which he fet up on a pillar near the roftrum ; but becaule it was not made for that latitude, it did not thew the time truly. They made use of it 99 years; till Martins Philippus fet up another more exact. *(7) The first profeffed writer on dialling is CLAVIUS; who demonftrates both the theory and the operations, after the rigid manner of the ancient mathematicians; but with fo much intricacy, that few perhaps ever read them all. Dechales and Ozanam give much easier demonstrations in their Courfes, and Wolfius in his Elements. M. Picard has given a new method of making large dials, by calculating the hour lines; and M. De la Hire, in his Dialing, printed in 1683, a geometrical method of drawing hour lines from certain points deter mined by obfervation. Eberhardus Welperus, in 1625, publifhed his Dialing, wherein he lays down a method of drawing the primary dials on a very eafy foundation. The fame foundation is defert bed at length by Sebaftian Munfter, in his Rudimenta Mathematica, published in 1551.

(8.) STURMIUS, in 1672, published a new edi tion of Welperus's Dialing, with the addition of a whole second part, about inclining and declining dials, &c. In 1708, the fame work, with Stur mius's additions, was republished with the addition of a fourth part, containing Picard's and de ja Hire's methods of drawing large dials. Pater fon, Michael, and Muller, have each wrote on dialling, in the German tongue; Coetfius in his Horologiographia Plana, printed in 1689; Gaup penius, in his Gnomonica Mechanica; Bion, in his Use of Mathematical Inftruments; the late ingenious Mir Ferguson, in his Select Lectures; Mr Einerfom, in his Diling and Mr W. Jones, in his Jiftrumental Dialing...

SECTION I. DEFINITIONS.

(9.) A DIAL is a furface, which is generally plane, upon which lines are defcribed in fuch a manner, that the shadow of a wire, or of the upper edge of another plant, erected perpendicularly on the former, may how the true time of the day.

(10.) The edge of the plane by which the time of the day is found, is called the STILE of the dial, which must be parallel to the earth's axis; and the line on which the faid plane is erected, is call ed the SUBSTILE.

(11.) The angle included between the fubftile and tile, is called the ELEVATION OF HEIGHT of the file.

(12.) Those dials whofe planes are parallel to the plane of the horizon, are called HORIZONTAL DIALS; and thofe dials whole planes are perpendicular to the plane of the horizon, are called VER

TICAL OF ERECT DIALS.

(13.) Those erect dials, whofe planes directly front the north or fouth, are called DIRECT NORTH OF SOUTH DIALS; and all other elect dials are

called DECLINERS, because their planes are turn ed away from the north or fouth.

(14.) Thofe dials whofe planes are neither para Jel nor perpendicular to the plane of the berizon are called INCLINING OF RECLINING DIALS, cording as their planes make acute or obtuf gles with the horizon; and if their planes are turned atide from facing the fouth or north, the are called declining inclining or declining-reclini dials.

(15.) The intersection of the plane of the dia with that of the meridian, paffing through the sti is called the MERIDIAN OF THE DIAL, or HOUR LINE OF XII.

(16.) Those meridians, whose planes passthroug the ftile, and make angles of 15, 30, 45, 60, and 90 degrees with the meridian of the pla (which marks the hour line of XII.) are call HOUR CIRCLES; and their interfections with plane of the diaf are called HOUR-LINES.

(17.) In all declining dials, the fubftile makes angle with the hour line of XII. and this angle called the distance of the fubftile from the meridia

(18.) The declining plane's difference of lo tude, is the angle formed at the interfection of ftile and plane of the dial, by two meridians; of which paffes through the hour line of XII. the other through the fubftile.

SECT. II. ILLUSTRATION of the PRINCIPLES DIALLING. See Plate: CI-CV.

(19.) If the whole earth aPcp, Fig. 1. were tra parent, and hollow, like a fphere of glats, and h its equator divided into 24 equal parts by fo ma meridian femicircles, a, b, c, d, e, f, g, &c. one which is the geographical meridian of any giv place, as London, (which is fuppofed to be at ti point a; and if the hours of XII were mark at the equator, both upon that meridian and t oppofite one, and all the reft of the hours in ord on the reft of the meridians, those meridians wou be the hour circles of London & then, if the sphe had an opaque axis, as PEp, terminating in th poles P and, the fhadow of the axis would ta upon every particular' meridian and hour, whe the fun came to the plane of the oppofite mendi and would confequently show the time at Londo and at all other places on the meridian of Londe

(20.) If this fphere were cut through the mid by a folid plane ABCD, in the rational horizon London, one half of the axis EP would be aboy the plane, and the other half below it; and ftraight lines were-drawn from the centre of th ptane to those points where its circumference cut by the hour circles of the sphere, those lit would be the hour lines of a horizontal dial t London: for the fhadow of the akis would t upon each particular hour line of the dial, wh it fell upon the like hour circle of the sphere.

(21.) if the plane which cuts the sphere be right, as AFCG, Fig. 2. touching the given pla (London) at F, and directly facing the meridian London, it will then become the plane of an er direct fouth dial : and it right lines be drawn the its centre E to thofe points of its circumferts where the hour circles of the fphere cut it, the will be the hour lines of a vertical or direct fout dial for London, to which the hours are to be i