Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/11

 M A G

MAG

gured on the drum* they fancy to themfelves fome prediction in regard to the things they are to enquire about. What they principally enquire into by this inftrument, are three things: I. What facrifices they fhall offer as moll acceptable to their gods. 2. What fuccefs they fhall have in their bufuieffcs or undertakings, fucb as hunting, fifh- ing, curing of difeafes, and the like. And, 3. What is done in places remote from them. On thefe feveral oceafions they life feveral peculiar ceremonies, and place themfelves in feve- ral odd poltures as they beat the drum, which influences the rings to one or the other fide, and to come nearer to one or tile other let of figures. And when they have done this, they have a method of calculating a difcovery, which they keep as a great fecret, but which feems merely the bufinefs of imagination in the diviner or magician.

MAGICAL (Cyd.) — Magical arrows, a fort of weapon very common among the barbarous inhabitants of Lapland, and many other of the northern climates, and fuppofed to pofTefs great and very Grange virtues. The people who are poflefled of them, pretend that they can, by their means, caufe difeafes even to people at a great diftance from them ; and not only difeafes, but any other kind of mifchiefs they defire ; and they pretend to practife this not only againit Grangers, but one another. There is a flory recorded in Scheffer's hiftory of this country, as a legend univerfally be- lieved among them, of a magician who, by means of one of thefe arrows, tore up a rock, near which another magician, with whom he was at enmity, was fleeping, and buried him under it.

MAGIOTAN, a name given by the people of Provence, and forne other places, to the {tony matter, as they efteem it, which choaks up in time the mouths of fome of their rivers. This is a foft fpongy matter, refembling a coarfe and very friable ftone ; and, according to the opinion of count Mar- flgli, it is no other than a congeries of the fand from the bot- toms of the rivers farther up the country, which is rolled downwards, and in thefe places is full of (parry and bitumi- nous matter, which, in the place where it meets the full body of fea-water, is ftopp'd and coagulated by it into this firm and folid ffate.

MAGMA, a word ufed by medical writers on many oceafions, fometimes in a very lax, and fometimes in a more appropria- ted fenfe. Some writers ufe it to exprefs a mafs of any thing -, others for a thick ointment made up with very little fluid matter, to prevent its running ; and others for the remains of an ointment after expreffion from its ingredients. Galen re- flrains the word Magma to exprefs only the faeces of miro- balans.

MAGNA (Cyd.) — Magna Jftza eligenia, a writ directed to the fheriff to fummon four lawful knights before the juftices ofaflize, there, upon their oaths, to chufe twelve knights of the vicinage, CffV. to pafs upon the great ajftze between A. B. plaintiff, and C. D. defendant, bfc. Reg. Orig. 8. Cowel.

MAGNALE, a word ufed by Van Helmont, and other enthu- fiaftical chemifts, to exprefs what he calls a kind of fpirit, which adminifters to fympathy and antipathy, and is the prompter and promoter of adtions, and by virtue of which magnetifm is conveyed, as by a vehicle, to a diftant object. In other places he fays Magv.aU, in mixed fubftanccs, is the aether, which is thinner than the air ; and, as he exprefles it, of an ambiguous nature between body and no body. In other places he fays, that as the Magnate has nothing like itfelf in treated beings, fo it will admit of no manifeffation by refem- blance. The Magnale, he fays, is not light, as many fup- pofe, but is a fort of conjugal form affifling the air.

MAGNANINE, in zoology, the name of a fmall bird deferi- bed by Aldrovand, Gefner, and fome other authors, and feeming to be the fame with our hedge-fparrow, commonly known among authors by the name curruca. Ray's Orni- tholog. p. 158.

MAGNES Carneus, in natural hiftory, a name given by Car- dan, and fome other authors, to a white earth dug in Italy and fome other places, and called alfo by many calamlta alba. It isan indurated earthy fubftance of the hardnefs of ofteocolla, and is ot a white colour variegated with black lines. It ad- heres very firmly to the tongue, and is hence faid to attract flefh in the fame manner as the magnet does iron. It is even pretended, that if an iron ftylus be rubed over with this flony earth, and then plunged into the flefh, the virtue of the earth will heal the wound as foon as made, and when the weapon is taken forth, there will remain no appearance of hurt. Cardan affirms that he faw this tried with fuccefs, but fuf- peits witchcraft in the cafe ! De Boet. de Gem. p. 474.

MAGNET (Cyd.)— Magnet, in medicine. Some writers of the middle ages have, from a miftaken tranflation of Theo- phraftus, been induced to account the load/lone poifonous, which the antients were fo far from doing, that they gave it inwardly. Galen afcribes a purgative quality to it, and re- commends it in dropfies ; and Diofcorides prefcribes it as a good medicine to evacuate grofs melancholic humors, it is doubtlefs puffeded of the fame virtues with the other ores of iron, though of late never ufed inwardly, being only made an ingredient in forne plafters. Sltppl. Vol.. If,

Arfemcal Magnet, a cauflic made of equal quantities of antimony, common fulphur, and white cryftalline arfenic; which are to be kept in a fand heat, till the whole melts into one uniform mafs; It fucceeds very well in taking down fungous flefh in wounds.

MAGNETIC Needle, in navigation, ii V. See the article Needle, Cyd.

MAGNETJCAL Meridian, in navigation! See the article Meridian, Cyd.

MAGNETIS Lap's, in the natural hiftory of the antients, the name given in different ages to two very different fubftances. The earlieft Greek authors expreffed by it the loadflone, which became afterwards called beracliiis lapis ; and then the word Magnetis was applied fo a very different ftone brought from the lame place, the neighbourhood of Magnefia in Lydia. This was a fine beautiful and bright fubftance, of a pure white, and fo very bright and glolfy, as to carry a refem- blance of polifhed filver. It was dug in large maffes, and was of a texture eafy to be wrought into any figure ; this made it in great efteem among the antients, who had it in con- ftant ufe turned into veflels of different kinds for the ufe of the table. It feems to be wholly unknown at prefent among the nations we have commerce with. Hill's Theophraft.

MAGNISSA, in mineralogy, a name given by fome of the an- tients to the white pyrites, called by others leucolithos and ar- gyrolithos. Many have fuppofed the Magnijfa to be the. fama with the magnefia, that is, manganefe, but this is an error ; nor is there the leafl fimilitude between the two ftones. It is plain, indeed, that the antients called a white and filvery look- ing ftone alfo by the name Magnefia ; but neither does this appear to have been the Magnijfa here defcribed, for Theo- phraftus defcribes it as a ftone that artificers ufed for turning things out of, which is utterly impoflible to be done with the pyrites; the mattery texture of which would make it fall to pieces on the flighted attempt to cut it into fhape by the wheel. The chemifts of the preceding ages have plainly un- derftood this word Magnijfa of the pyrites, and have made thefe two words and thefory fynonymous. Pliny mentions a gold-coloured and filver-coloured pyrites ; thefe therefore were diftinctions fufficient for the white and yellow pyrites ; but Diofcorides has only mentioned one kind of the marcafite or pyrites, which is the yellow or brafiy one, the moft common of all the fpecies. When the word pyrites, therefore, was only the name of this yellow ftone, it is not wonderful that the white one fhould be called by another name, as Magnijfai See the article Marcasite.

MAGNITUDE (Cyd.)— Geometrical magnitudes maybe ufe- fully confidered as generated or produced by motion. Thus lines may be conceived as generated by the motion of points • furfaces, by the motion of lines ; folids, by the motion of fur- faces ; angles may be fuppofed to be generated by the rota- tion of their fides.

Geometrical magnitude is -always understood to confiffc of parts ; and to have no parts, or to have no Magnitude, ate confidered as equivalent in this fcience. There is, however, no neceiiity for confidering Magnitude as made up of an in- finite number of fmall parts ; it is fufficient that no quantity can be fuppofed to be fo fmall, but it may be conceived to be farther diminifhed ; and it is obvious, that we are not to eftimate the number of parts that may be conceived in a given Magnitude, by thofe which in particular determinate circum- ftances may be actually perceived in it by fenfe, fince a greater number of parts become fenfible, by varying the circumftances in which it is perceived. See Mac Laurin's Fluxions, Art. 2QO, 2or.

Many of late have fuppofed geometrical Magnitude to be com- pofed of infinitely fmall parts, and infinite in number ; and hence have raifed many paradoxes and myfteries in a fcience wherein there ought to be none. Nay, infinitely fmall parts of infinitely fmall parts, £JV. ad infinitum, have been intro- duced without the leafl neceffity. See Mac Laurin's Fluxions in the Introduction, where he makes feveral remarks on Mon- fieur de Fontenelle's Geometric de L'infini. See the article Extension.

MAGNOLIA, in botany, the name of a very beautiful genus of plants, the characters of which are thefe : The perianthium is compofed of three oval, and hollow leaves, which look like petals, and fall with the flower. The flower confifls of nine petals of an oblong form, hollowed, narrow at the bate, and broader at the apex, and terminating in an obtufe point. The ilamina are very numerous, fhort, and pointed filaments ; they grow to the common receptacle of the piftil, which is placed beneath the germen, and are of a compreffed figure* The anthers arc oblong and flender, and grow on every fide to the filaments ; the germina are numerous, of an oval ob- long figure, and are placed about a clavated receptacle ; the ftyles are crooked and contorted ; the fligmata are placed longitudinally on the ftyles, and are hairy ; the fruit is a ftro- bilus of an oval form, with compreffed, roundifh, and fcarce imbricated capfules ; thefe are compofed of two valves, and contain one cell ; they ftand clofe to one another without pe- dicles, and open in their outer part. The feeds are fingle, and £ bang