Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/584

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DATE, in zoology, a name under which Nieremberg has de- scribed a bird of the fize of a pigeon, which, he fays, lays forty or fifty eggs, each as large as that of a goofe, but having no white : thefe eg~s, he f.ys, as well as the bird itfelf, are commonly eaten, and are called by the Indians Taptm\ and that if dies a hole in the (and in a ditch -bottom, and there lays, and leaves the eggs covered with fand to be hatched by the fun. Ra/s Ornkhol. App. p. 29.

Mr. Ray declares all this to be falfe and fabulous, and is of opinion that there h no fuch bird in nature; for though there are fome birds which lay eggs very large in proportion to their own fize, as the wild fwan, and fome of the fmaller water- fowls, yet thefe birds lay only one fuch egg ; not to mention the great improbability of any egg being without a white.

DAILE, in a fhip, the trough wherein die water runs over the decks.

DAIS. See Deis;

DAISY, Great Daisy. See Leucanthemum.

DAKER Hen, in zoology, the Englifh name for the ortygo- metra, a bird of the gallinaceous kind, fomewhat refembling the quail, and called by the Italians the king of the quails, Re delk quaglle. It is larger than the quail, and is common in Ireland, and in fome of the northern counties of England. Ray's Ornithol. p. 122. See Ort'ygometra.

DAKIR, in our ftatutes, is ufed for the twentieth part of a laft of hides.

According to the ftatute 5 1 Hen. 3. De compoftt'wie fonckritm is' menfurarum, a laft of hides confifts of twenty Dakirs, and every Dakir of ten hides. But by 1 Jac. cap. 33. one laft of hides or fkins is twelve dozen. See Dicker.

DALE A, in botany, the name of a genus of plants, the charac- ters of which are thefe : the cup is fmall, one leaved, and divided into five fegments. The corolla is compofed of five petals, which are unequal ; four of them being oblong, ob- tufe, {trait, hollow, and equal in fize ; and the fifth, which ftands above, fmaller than the others. The ftamina are ten diadclphous filaments ; the anthers are roundifh ; the ger- men of the piflil is oval, and terminates in a pointed ftylus of the length of the ftamina ; the ftigma is fimple ; the fruit is an oval bivalve pod, confining of only one cell, and containing only one feed. Linnm Gen. Plant, p. 336.

DAMASONIUM, in botany, the name of a genus of plants, called by moft authors by a very improper name, ftarry-headed water-plantain. The characters of the genus are thefe : the flower is of the rofaceous kind, ufually confifting of three leaves, difpofed in a fort of circular form. From the flower- cup arifes a piflil, which finally becomes a ftar-fafhioned fruit, confifting of feveral capfules, and containing oblong feeds. There are only two known fpecies of Damafonium: 1. The common Damafonium, called ft a rry-hcaded water-plantain : and 2. The great American Damafonium? with plantain leaves, yellow flowers, and a glohofe fruit.

DAMATRIUS, in antient chronology, theBceotian name of the

■ Athenian month Pyancpfitm, which was the fifth of their year, and correfponded to the latter part of cur October and begin- ning of November. See Pyanepsion and Month.

DAMIER, in conchyliology, the name given by French riatu- ralifts to that elegant fpecies of voluta, the fpots of which Hand in a chequered order, and referable the marks of a draught or chefs-board, that being the common fignification of the word Darner. See Voluta.

DAMPS, (Cycl.) — The pernicious damps in mines {hew abun- dantly, that nature affords us inflammable air in fome cafes ; and we have found by experiments that art can do the fame, and that very probably on the fame principles with the natural. Sir James Lowther having collected the air of fome of thefe damps in bladders, preferred it fo well, that, when brought up to London, it would take fire at the flame of a candle, on being let out by the orifice of a piece of tobacco-pipe. It is well known to all that are verfeo* in chymical experiments, that moft metals emit a great quantity of fulphureous vapours during the effervefcence they undergo in the time of their fo- lutions in their refpedtive menftruums. On this principle Mr. Maud founded his attempt of producing an inflammable air by art, like the natural one. It is obferved that iron, while under folution with oil of vitriol, emits a very great quantity vS thefe vapours, which are very fubtile, and not eafily con- denfed. This vapour being received into bladders, in the fame manner with the natural air of Sir James Lowther, took fire in the fame manner, oh being let out in a fmall ftream, and anfwered all the phenomena of the natural kind. The exatSt. method of preparing it is this : Take two drams of o:i of vitriol, mix it with eight drams of common water ; put this into a glafs with a flat bottom, about ten inches wide and ■three deep, with a long neck. To this put in two drams of filings of iron. The folution inftantly begins with great heat and ebullition, and vapours are copioufly thrown up to the top of the neck of the glafs. Lute a bladder empty of air, and, with a tobacco-pipe faftened in its neck: the fumes of the folution will foon fill up the bladder. Vv hen it is blown full, tie the neck faft with a firing, and then put another in its place; and fo on, taking them away as faft as they fill. The air being afterwards let out at the hole of the tobacco-

pipe, will take fire at the approach of th ■ flame of a candle. it ufually happens, that in removin ; hands to prefs I ie

bladder in other places, after fome oi the air is fqueezed out, the fire is fucked into the bladder: in this cafe it fires all the remaining air in the bladder at once, and goes c'ft with a vio- lent exploflon, like the report of a gun. One thing very worthy of notice in the courfe of this experi- ment, is, that the air which mcceffivcly fills feveral bladders, during the time of the effervefcence, mull: have been either generated a*e novo r ovt of the mixture, or elfe recovered from being locked up in the body of the metal in an unelaftick ffate. This experiment will eafily explain a very probable caufe of earthquakes and volcanos, and all other fiery eruptions out of the earth ; fince by this it appears, that nothing more is necef- fary to form them than an intervention of iron, with a vitrio- lick acid, and water. Now iron is generally four- d accompa- nied with fulphur, and common fulphur may be analyfed into an inflammable oil, and an acid liquor, like oil of vitriol. This acid therefore in the bowels of the earth, by being di- luted with a little water, becomes a menffruum capable of a£Hng upon iron, as above deicribed ; and an effervefcence arid inteftine heat and tumult muft be the confequence. The air which comes from the mixture is rarified ; and by how much the more it is comprefled by the incumbent earth, by fo much the more its impetus will, at length, be iricreafed to an unlimited degree, and like gunpowder it will caufe explofions, and make earthquakes and eruptions. Nor does there always need the accefs of fire to fet thefe vapours to work ; for the air in the bladders, if it have been very much heated, will of itfelf take fire as foon as it is brought into contact with the external air. Philof. Tranf. N°. 442. p. 282. and 286. The German miners think themfelves not qualified for their bufinefs, if they are not able to make their weather, as theyexprefs it; that is, to cure their damps. Thefe are of various kinds in their mines ; fome fo firong that they fuf- focate the workmen ; others lefs violent, and only making them faint, without doing them any farther hurt, unlefs they are fo imprudent as to continue a long time in the place. The common way of curing the damp is by letting the air in and out, and caufing a circulation in it. They fometimes have cured very confiderable damps by blowing, lor many days to- gether, with large bellows : but the ordinary method of work- ing is by means of long tubes communicating with the air above, by means of which they have continual frefh air, and are able to work on as far as they pleafe. Some of the cuni- culi of thefe mines are five hundred fathoms long; and in the filver trinity-mine by Sebemnitz, there is a paflage quite thro* a very large hill, coming out on the oppofitc fide to that where it enters. The tubes always anfwer very well in the horizon- tal cuts ; but not in the perpendicular ones, when they go to great depths : in thefe they place a tube all the way down by one fide, and they then fit a piece of wood-work to the fize of the hole or cut ; and feveral times in a day they are forced to thruft this down, in order to force up all the foul air that is in the pit by the tube, to give room for frefh air in its place. Phil. Tranf. N 9. 48.

In fome of the coal-pits in the neighbourhood of Men- dip hills, fire-damps almofr continually happen, fo that great numbers have been killed, maimed, and burnt by them. The colliers however continue their work notwithftanding, only uiing the cautions of renewing their air very quick, and ufing no candles in their work but thofe of a fingle wick, and of fixty or feventy to the pound; which notwithstanding will give as good a light there, as others of ten or twelve to the pound in other places. They always have the caution to place even thefe behind them, and never prefent them to the breaff. of the work. When any perfon is burnt by thefe damps, they prefently betake themfelves to a good fire, and, fending for a large quantity of cows milk, they bathe the burnt places with this while warm ; and. afterwards the places will heal by the common cooling ointments, and healing plaifters. In regard to the periodical returns of thefe damps, mentioned by fome, we find that by the caution of fmall candles, ufed by the colliers of thefe places, that there is a continual propenfity in them to take fire at all times of the year ; and though thefe works feldom do take fire, yet, as the colliers fay, they are moft fubjectto it in the violence of winter, and chiefly in a black froft. Thedanger of firing is alike both in wet and dry grounds. There are no fumes coming out at the mouth of any {haft in thefe places, which will take fire at lighted torches or candles "being held over them. They fometimes take fire of themfelves, and fet fire to the coal cf the mine : they feem to be as fre- quently on or near the floor of the pits, as about then* roofs ; and no current of vapours, or wind, is to be met with at the mouths of the fhafts by which they go down to thefe pits. In wet works there are many times bubbles {binding on the fur- face of the water, which will take fire if a candle he held to them ; but thefe, on a clofe examination, do not appear to be occafioned by fubterraneous vapours; but are owing to the dropping of water from the roof of the mine, or the falling in of pieces of coal. Thefe damps are commonly obferved in our coal-pits; but the lead-mines on Mcnciip-hiKs are alfo fometimes aSe&ed by them. Philof. Collect, p. 8.

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