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ftonevariagated with red fpots. There are fome fabulous ac- counts recorded of its virtues, fuch as its preventing drunken- nefe, and giving water the taile of wine. Some of the wri- ters of the middle age have attributed many other virtues to the ftone of this name j but they fome what deviate from Pliny's account in their defcription of it : they fay it is of a fcrrugineous colour variegated with white, and that it is found only in the Eaft- Indies ; thefe are too fhort defcriptions to be certain what ftone they were intended for. Pirn. 1. 37. c. 10. Hofm, Lex. in voc.
DIOECIA, in Botany, a clafs of plants which have the male and female parts, not in the fame, but in different flowers, and thofe not on the fame individual, but on different plants of the fame fpecies ; either of which, though they are called the male and female plants, from their thus carrying the feparate male and female flowers, might have arifcn from the fame feed. The word is formed of the Greek fa twice, and oik®- habita- tion. Among the plants of this clafs are the willow, mifletoe, hemp, fpinach, &c.
All the plants of this clafs are in the different indivi- duals, diftindtly males and females ; and thence in every fpecies of this clafs. There is a male and female plant, which in the time of flowering appear very different from one ano- ther. The male plants, as well as the others, growing from the feeds of the fame individual female plant : and it is found, that the female plants of this clafs never produce perfect feeds, or fuch as can yield plants from fowing, unlefs there be a male plant of the fame fpecies near them at the time of their flower- ing. It is obferved in fome of the fpecies of this clafs, that though in general the plants raifed from the feeds are fome male and others female feparately ; yet there are fome which are hermaphrodites, or have the two fexes conjoined. It is a curious observation, that there are no feparate male and fe- male plants in the claffes of the afperifoliate or ftellate plants, nor in the umbelliferous clafs, or that of the didynamia, tetra- dynamia, monadelpbia, diadelphia, or fyngenefia. The rea- fon of which appears very evidently, from an obfervation of the conduct of the fructification in thofe clafles. Linnai Gen. Plant, p. 470.
DIOMEDIS Avis, in Zoology, the name of a bird of the web footed kind, with a (lender beak, hooked at the end, and with its hinder toe not connected by the membrane that joins the reft. It is of the fize of a common hen, but its neck and legs are much longer : its colour is a dusky, and fomewhat greyifh brown, and under the belly there is more or lefs white: its beak is of a fine red, or in fome of a yellowifh colour, with a black end. It is found in the Infula Diomedea, now called Tre- miti, in the Adriatic Sea, and is faid to be peculiar to that place.
DIOPTRA, among the antients, an inftrument invented by Hipparchus, which ferved for feveral ufes, as to level water ; to take the height of towers, or places at a diftance ; to deter- mine the places, magnitudes, and diftanccs of the ftars. Hofm. Lex. in voc.
DIORTHOSIS, in furgery, an operation, by which crooked or diftorted members, are made even, and reftored to their pri- mitive and regular ftiape.
DIOSCOREA, in Botany, the name of a genus of plants, the characters of which are thefe : it produces feparate male and female flowers ; the cup is a one leaved perianthium, of a bell like fhape, divided into fix lanceolated fegments, which expand at the top ; there is no other flower but this cup. The fta- mina are fix very fhort capillary filaments, with fimple an- thers. In the female flowers, the cup is the fame as in the male, and there are no petals. The piftil has a fmall trigonal germen, from which arife three ftyles of a fimple ftrudture, terminated by fimple ftigmata. The fruit is a large triangular capfule, which has three cells, and is compofed of three valves. The feeds are two in each cell, and they are comprefled, and have a membranaceous ring. Linnaeus obferves, that he could never trace out the cup, as Plumicr defcribes it in the dried fpecimens. Linnm Gen. PI. p. 479. Plwn'ier Gen. 26.
DIOSCURIA, AniDcov^a,, in antiquity, a teftival in honour of the Aiosrxoug?/, or Caftorand Pollux, who were reputed to bethefonsof Jupiter. It was obferved by the Cyrenaans, but more efpecially by the Spartans, whole country was ho- noured by the birth of thefe heroes. The folemnity was full of mirth, being a time wherein they fhared plentifully of the gifts of Bacchus, and diverted themfelves with fports, of which wreftling matches always made a part. Potter^ Arch^ol. Giaec. 1. 2. c. 20. T. 1. p. 384.
DIOSPIROS, in Botany, a name given by Pliny, and fome other authors, to the plant called LacTymaJob'^ or Job's tears. Ger. Emac. Ind. 2.
DIOSPOROS, in Botany, a name given alfo by fome of the anti- ents to the lithofpernum or grom well ; fome chute to write it DiofpyroS) but this feems erroneous. The plain derivation of the word, being from the Greek J 1 /©- avo^i, the feed of Ju- piter. It feems to have obtained this name from its beauty and hardnefs. Piiny, 1, 26.
DIOSPYROS, in Botany, the name by which Linnaeus calls the Guiacana, of Tournefort and others. Linnai Gen, PI. p. 166. See Guiacana. Suppl. Yol. I.
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DIOSPYRUM, in Botany, a name by which fome authors have called the milium folisor gromwell. Ger. Emac. Ind. 2.
DIOTA, among chymifts, a term ufed for a circulating or double veffel.
DIPHRIS, a ftone mentioned by the antient writers ; and faid, by Pliny, toibe of two kinds, the one black, the other white ; and that thefe carried each of them the mark of one of the fexes, defcribed by a line of the oppofite colours: they were therefore called the male and female : the white was called the male, and had the character of the male fex figured in a black line, the other the female ; and had the marks of that fex de- fcribed by a white one : we know no fuch ftones at this time.
DIPHTHERA, AijSsja, among the antients, a garment made of skins, and worn only by fhepherds and country labourers. Hofm. Lex. in voc.
DIPHYES, in natural hiftory, a name given by fome authors, to a kind of ftone, which reprefents both the male and female parts of generation of the human fpecies. We have ftones which reprefent the figures of fhells, becaufe they have been formed in them : and nothing can be more proper than the calling them by the name of the (hell, from which they bor- row their figure ; but this is not to be fuppofed the cafe in re- gard to this ftone, which has nothing to do with thofe parts in its formation, but owes its figures merely to the accidental con- formation of tire hinge and protuberances of a (hell, in which it has been formed. We have a fpecies of chama, whofe external form at the mouth reprefents the female pudenda ; but the figure of this ftone is owing to the internal fhape of the fhel], in which it has been caft. This is an unknown fpecies of concha anomia, which has fuch ridges on one fhell, and fuch cavities in the other, that the ftone caft or moulded in it, has on one fide the figure of the female pudenda, and on the other of the male : it is ufually of a dusky brown colour, and of a ferrugineous fubfbnce ; as the fame fhell may, however, have received in different places different fubfrances into its ca- vity, all which would neceflarily be of this form, we hear, among authors, of fome black, and fome white ftones of this kind. Authors have treated of this ftone in a very idle and fabulous manner, but this is its true hiftory.
DIPLASIASMUS, in medicine, a reduplication of difeafes. Diplafiafmus is alfo ufed for two mufcles of the arm, which ferve to turn it about. Blancard.
DIPLOIS, 4irt«, in antiquity, a double pallium, or cloak, worn chiefly by the Cynics. Hofm. Lex. in voc.
DIPONDIUS, in the fcripture language, is ufed by St. Luke ", to fignify a certain coin, which was of very little value. Our tranflation of the paflage is, are not two fparrows fold for twb farthings ? In St. Matthew ", who relates the fame thing, we read, Are not two fparrows fold for a farthing ? The Greek reads Affarion inftead of As. Now AJfarion, as fome fay, was worth half an As, that is to fay, four French deniers and \ : and, according to others, two deniers and ~?. Dipondius feems rather to fignify half an As. Calmet, Didion. Biol. [ a Luke xii. 6. ' Matt. x. 29.]
Dr. Arbuthnot differs in opinion from the author laft quoted. He fays, that this coin was at firft libralis, or of a pound weight, and even when diminifhed it retained the name of Bella. So that Dipondius denoted two Affes. Arluth. tables of antient coins, &c. c. 3.
DIPPING, (Cyd.) in mineralogy, a term ufed to exprefs the deviation of the veins of ore, from that regular and ftrait line, in which they ufually run. A great deal of the skill of the miners coniifts in the underftanding this dipping of the veins, and knowing how to manage in it. In Cornwall they have this general rule to guide them in this refpefl : molt of their tin loads, which run from eaft to weft, conftantly dip towards the north. Sometimes they underlie ; that is, they Hope down toward the north three foot in eight, perpendicular. This muft carefully be obferved by the miners, that they may exactly know where to make their air fhafts when occafion re- quires ; yet, in the higher mountains of Dartmaer there are fome confiderable loads, which run north and fouth : thefe al- ways underlie toward the eaft.
Four or five loads may run nearly parallel to each other in the fame hill ; and yet, which is rare, they may meet all together in one hatch, as it were a knot, which well tins the place, and fo feparate again, and keep their former diftances. Phil. Tranf. N° 69.
DIPSACUS, teafell, in the Linnaean fyftem of Botany, makes a diftinct genus of plants; the characters of which are thefe: the calyx is a common perianthium, containing many flowers, and compofed of feveral flender little leaves, placed round the receptacle, and longer than the flowers. The flower is formed of one leaf, or petal, the whole making a ftrait tube, divided in- to four fegments ; at the extremity all placed erecte and the outer one larger and more pointed than the reft. The fta- mina are four capillary filaments longer than the flower. The antherje are laid clofely on them. The germen of the piftil is placed below the proper receptacle of the flower ; the ftyle is flender, and of the length of the flower, and the ftig- ma is fingle. The fruit is one large and common receptacle, of a conic form, made up of the leaves of the cups longer than 9 G thofe
