Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/54

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flefhy, foft, and unicapfular, containing feveral ftones, each having an oblong kernel. See Tab. of Botany, Clafe 21. The fpecies of Mefpilus enumerated by Mr. Tournefort, are thefe: i. The common wild Medlar, or German Medlar, with bay-like, not ferrated leaves, 2. The greater bay- leav'd Medlar. 3. The great fcay-leav'd Medlar, with an early-ripe, oblong, foft, and fweet-tafted fruit. 4. The great bay-leav'd Maple, with a foft fweet-tafted fmallcr fruit. 5<The Medlar with a middle-fized oblong auftere and ill-tafted fruit, with the corona always clofed. 6. The parfley-leav'd Mefpilus, called the lazerolc, 7. The double-flowered jag- ged apium-leav'd Mefpilus. 8. The Laxerole, with a large deep red and well-tafted fruit. 9. the Lazerole, with a fmaller yellowifh fruit. 10. The wild fmall-fruited yellow- ifh white La%erole, with a turbinated fruit, ir. 1 he Ca- nada fervice-leav'd Mefpilus. 12. The prickly Mefpilus, with pear-like, fhining, and denticulated leaves, and with very beautiful red fruit. 13. The common apium-leav'd prickly Mefpilus, called the white thorn. 14. The common whitethorn, with double flowers. 15. The almond-leav'd prickly Mefpilus. 16. The barren wild trifoliate apium- leav'd Mefpilus, with very ftrong thorns. 17. The large- fruited wild Mefpilus, with ftrong prickles, and with hairy palmated apium leaves. 18. The roundifh-leav'd Mefpilus, with black fweetifh fruit. 19. The roundifh-leav'd Mefpi- lus, with red fruit. And 20. The American Mefpilus, with red fruit, and with broad leaves prickly underneath. Town. Inft. p. 644. See the article Medlar.

MESSE da Capella, in the Italian mime, is ufed for mafl'cs fung by the grand chorus. In thefe, various fugues, double counter- points, and other ornaments, are ufed Broffard.

Messe Concertaie, in the Italian mufic, is a mafs wherein the parts reciting are intermixed with chorufles. Broffard.

MESUA, in botany, the name of a genus of plants, the cha- racters of which are thefe : The perianth'mm is permanent, and confifts of four fmall oval leaves. The flower confifts of four large hollow and rounded petals. The ftam'ina are nu- merous filaments, of the length of the cup. The anthers are fimple. Tbe germen of the piftil is roundifh. The ftyle is fimple ; and the ftigma indented in four places. The fruit is a roundifh, pointed, coriaceous capfulc, with four longi- tudinal futures. It is compofed of four valves, and contains four large flefhy, obtufe, three-corner'd, and turbinated feeds bedded in it. Linnai Gen. Plant, p. 235. Hort. Mai. vol. 3. p. 53.

METACAL, an Egyptian weight, ufed in the weighing of pearls, and confifting either ofacarratand a half, or of two carrats. Sixteen of thefe carrats make a dram, each of the carrats weighing four grains, and twelve drams an ounce. Pocod's ./Egypt, p. 175.

METACARPUS, a fmall very flefhy mufcle, fituated ob- liquely between the large internal annular or tranfverfe liga- ment of the carpus, and the whole inlide of the fourth meta- carpal bone.

It is fixed by a fmall fhort tendon to the os orbiculare, and to the neighbouring part of the large iigament of the carpus ; from thence its fibres run more or lels obliquely toward the infide of the fourth metacarpal bone, in the outer edge of which they are inferted. The fibres of this mufcle are of un- equal lengths, and extend all the way to the articulation of the firft phalanx of the little finger, with the fourth metacar- pal bone ; but they have no manner of relation to that finger. IVinflow's Anatomy, p. 194.

METACARPUS (G>7.)— The anticnt anatomifts reckoned five bones in the metacarpus, including that bone which is now looked upon to be the firft phalanx of the thumb, the rejecting which from amona; them, has reduced the number to the four we allow. TheTe bones are all long, thicker at their extremities than in the middle, and of unequal length and bignefs : The two firft are fometimes, though very rarely, equal, and the others leilen by degrees from them. Anatomifts, in their defcriptions, divide each of thefe bones into a middle and two extremities, or into a bafis, bodv, and head. The bafes of them all are angular, and turned toward the carpus, and their head rounded like condyles, and turned toward the fingers. Both extremities are covered with carti- lages, and the heads remain for a long time very diftinct epiphyfes.

The firft bone of the metacarpus is longeft and largeft, and fupports the fore finger ; its bafis is a little hollow, aufwering to the digital fide of the os pyramidale of the carpus. On the outer edge there is a fmall angular notch, and on the cubital edge of the bafis is a fmall lateral fide, which is articulated with the bafis of the fecond bone. "J he inner edge is ter- minated laterally by an oblique angle, which is articulated with the neighbouring angle in the bafis of the os magnum ; round the bafis are inequalities and depreffions for the liga- ments and articular glands. The outfide of the body of the bone is broader toward the head than toward the bafis. The fecond bone of the Metacarpus fupports the middle finger, and has this very peculiar in it, that its bafis is very oblique, terminating at the outer edge by an angular point toward the firft bone. By the triangular fide of its bafis it is articulated with the bafis of the os magnum, and by its lateral fides with

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thofc of the firft and third bones of the Metacarpus. The third bone is that which fupports the ring finger, being lefs than the firft and fecond. Its bafis is irregularly triangular, and proportionably lefs than the two former, and by the prin- cipal fide thereof, it is articulated with the firft half of the fide of the os unciforme ; the fmall lateral fides of the bafis join thofe of the fecond and fourth bone. The fourth bone fup- ports the little finger ; the principal fide of the bafis of this, inftead of being triangular, as in other bones, is all of an equal breadth, a little oblique, and fome part of it gently convex, the reft gently concave, and articulated with the fecond half of the fide of the" os unciforme ; by its lateral fide it joins the correfponding fide of the bafis of the third bone, but in a much loofer manner than in the other articulations of that kind. In the oppofite fide there is a fmall tuberofity, JVhiflovj's Anatomy, p. 86.

^•^ra j///^ Metacarpus. In fractures of the hand ox Metacarpus, the beft method of reducing and replacing the bones, is, to extend the hand upon a fmooth table, and while an affiftant holds the whole hand evenly in that pofture, the furgeon is to replace the bones ; and when that is care- fully and perfectly done, to fecure them with a proper ban- dage. Heifter, Surg. p. 129.

Luxation of the Metacarpus. The four fmall bones in the palm of the hand are fometimes luxated from the carpus to which their upper parts are connected; this happens from external violences, not unfrequently, notwithftanding that thefe bones naturally muft much relift fuch a luxation; for the two carpal bones, which are feated in the middle between the two external ones, cannot be diflocated to either fide, as the two external ones, which fuftain the firft and little fingers, cannot be luxated inwardly, but are very eafily driven outward ; and each of them may be luxated on the fore or back part of tbe hand ; but which ever of thefe hap- pens, the particular diforder may be difcovered and examined by feeling and infpecting, and the cure may be performed by extending the hand on a flat board or table, and replacing with the thumb whatever of the bones have ftarted from their natural fituation. Heifer's Surg. p. 166.

METACHORESIS, a word ufed by Galen to exprefs a recefs of a morbid humour from one part of the body to another, a thing very common in many diftempers.

METACOE, in botany, a name given by the people of Guinea to a plant, of which they are very fond, becaufe of its virtues as a balfamic and vulnerary. Its leaves, being bruifed and applied to a frefh wound, cure it. _ They have alfo another ufe for it, twifting the dried leaves into a fort of match for their mufkets. Phil. Tranf, N°. 232.

METAGITNION, MiTa^.W*, in chronology, the fecond month of the Athenian year. It contained twenty-nine days, and anfwercd to the latter part of our July and beginning of Auguft. The Boeotians called it Pammus, and the people of Syracufe, Carnlus.

It was io called from Metagit?iia, one of Apollo's feftivals kept in it. Vid. Potter, Archseol. Gra^c. T. 1. p. 414.

METAL {Cyd.) — Experiments on Metals, made with the great burning-glafs at Paris, have proved, that all the imper- fect metals, copper, iron, tin, and lead, are compofed only of two parts, a fulphur or oily matter, and a more denfe fub- ftance, called their earth, capable of vitrification. That from this oil or fulphur proceed the opacity, the glittering briehtnefs, and the malleability of thefe metals; that this ful- phur or oil feems no way different from the oils of vegetables and animals, and that it is the fame in all the four imperfect Metals, and in mercury : That thefe four metals have a dif- ferent fubftance for their bale, the earth of each vitrifying in a different manner ; and that to this is owing their difference from one another. Mem. Acad. Par. 1709.

Specific Gravity of 'Metals. The fpecific gravity of Metals can never be very exactly determhi'd, for it varies a little from many caufes ; firft, according to the different heat of the atmolphcre, which expands water, and other fluids, in- finitely more than it does folid bodies ; and by that unequal diminution of the weight, makes it impoffible to affign them a conftant proportion, unlefs the heat be determined with the oreateft exactnefs. Secondly, accordingto the feveral degrees of purity in the water, which difference is ffimetimes founJ not inc'onfiderable. Thirdly, according to the different pu- rity of the Metals ; for there is hardly any Metal found {a very pure, but that it may be eafily demonftrated to be mixed with fome others. Fourthly, according to the different weight of the atmofphere itfel'f ; though the effects of its va- riations be not fo confiderable as of the reft. Cramer, Ait. Affay. p. 4.

Hence it is that there are, in a manner, as many different accounts of the fpecific gravities of Metals as there are authors who have given an account of their experiments on the fub- ject. However, except the Metals be of a very great impu- rity, the fum of all the variations refultiug from all thefe caufes, is not fufficient to hinder any Metal from being cer- tainly diftinguifhed from any other Metal, by its fpecific gravity.

Slight variations in hydroftatical experiments are indeed

neither new tilings, nor are they by any means avoidable,

a either