Page:Cyclopaedia, Chambers - Volume 2.djvu/740

 SLA

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S L E

'jUCfpi, which Signifies at the fame time, both tight Combat and Joy. Menage derives it from the German, Schirmen or Skefuien, to Fence. He Cange, from Scaram-iiccia, a light Engagement, of Sara and Muccia, a Body of Soldiers hid in Ambuffi ; in regard molt Skirmipes are performed by Perfbns in Ambuicade.

SKULL, in Anatomy. See Cranium.

SKY, the blue Air or Atmofphete. See Atmosphere.

The Azure Colour of the Sky, Sir Ifaac Newtm attri- butes to Vapours beginning to condenle therein, which have got Confluence enough to reflect the molt reflexible Rays, viz. the Violet ones ; but not enough to reflect any of the lefs reflexible ones. See Reflexibility. _

Nl.de la Hire attributes it to our viewing ablackObje£t,w'z-. The dark Space beyond the Regions of the Atmofphere, thro' a white or lucid one, viz. the Air illumined by the Sun : A Mixture of Black and White always appearing Blue. See Blue.

This Account is not his 5 'tis as old as Leonardo da Vinci.

SLAB, the Outfide i'appy Plank or Board law'd off from the Sides of a Timber Tree.

SLAUGHTER. See Man-slaughter.

SLATE, a blue fofllle Stone, very foff when dug out of the Quarry, and on that Account cafily cut or law'd into thin long Squares or Eicallops, to ferve in Lieu of Tiles for the Covering of Houfes. See Covering. 'Tis fometimes alio uftd to make Tables of; to Pave withal, He. ,Tne Ancients were unacquainted with the Ule of Slate, and inftead thereof cover'd their Houfes with Shingle, as we read in 'Pliny. Befides the Slue Slate, we have in England a Greyift Slate, eall'd alio Horpam Stone, from a Town in SuJJex of thar Name, where the greateft Quantities of it are tbund.

The Slue Slate, is a very light, lafting, and beautiful Co- vering but chargeable withal, in regard the Roof rmift be firft Boarded over, the Slates hung on Tacks, and laid with finer Mortar than Tiles. The Grey Slate is chiefly uied in the Covering of Churches, Chappels, Chancels, £ffc.

'Tis dearer than Tiles, but far more durable. The Timber of the Roof needs to be very flrong for thefe Grey Slates, it being almoft double the Weight of Tiles. See Tile.

To judge of the Goodneis of Slate, Mr. Coleprefs, in the Thilofophical LranftcJions, orders it to be knocked againft any hard Body, to make it yield a Sound : If the Sound be good and dear, the Stone is firm and good ; otherwife, 'tis crazy.

Another Method of proving its Goodncfs, is, by weighing it exactly, then letting it lie 6 or 8 Hours under Water, and wiping it very clean, if ir weighs more now than it did before, 'tis of that Kind that foaks in Water, and therefore will not long endure, without rotting the Lath or Timber. Another Method of Trial is, by placing a Slate half a Day perpendicularly in a VefTcl of Water, fo as to reach a con- siderable Height above the Level thereof : If the Slate be firm and dofe, then it wiil not draw Water, that is, the Water will not have afcended above half an Inch above the Level of that in the VctTcl, nor that perhaps any where but at the Edges, the Texture whereof might be loofened by hewing; but a bad Stone will have drawn the Water to the very Top, be it as high as it will. There are Slates in fe- veral Places, which the moft experienced Slaters, or Co- vcrers, conjecture to have continued on Houfes feve'ral Hun. dreds of Years, and are yet as firm as when firft put up.

M. Leibnitz informs us, in the Hiftory of the French Academy, that in leveral Parts of the Dutch y of Srmfiuck, particularly about Ofleroda, (£c. there are Horizontal Veins of Slate, wherein ate found very exact and finifti'd Repre- sentations of various Kinds of Fifties and Plants, appearing in their natural Breadth and Length, but without any Thicknefs The fame Impteflions are alfo frequently found even in a Mixture of Copper and Silver. M. Leibnitz ac- counts for this Appearance, by iiippofing the Lakes and Meadows of the Places to have been cover'd over with a Kind of Earth, which has buried the Fifties and Plants • or that fbme very muddy Water, much impregnated with Earth, has covered them up, or carried them away This Earth he takes to have fincc hardned into Slate ; and length of Time, or fome other Caufe, to have confumed the deli- cate Matter of the Fifti, &. Much as the Bodies of Flies or Ants, which are found enclofed in Amber, are quite diffipated, and nothing left but a mere Delineation. The Matter of the Fi/h, or Plant, thus confumed, has left its Form imprefled in the Slate, by means of the Cavity re- maining therein ; which Cavity has been at length filled up with a Metallic Matter. Whether that the Subterranean Fire, in baking the Earth into Slate, has feparated the Metal therefrom ; or whether a Metallic Vapour penetrating the Slate, has become fix'd in thefe Cavities.

SLAVE, a Perfon in the abfolute Power of a Mafter either by War or Conqueft. See Servant. '

We find no mention of Slaves before the Deluge- but immediately after, viz. in the Curfe of Cain Gen. ix „ whenee 'tis eafily inferred, that Servitude commenced Toon

after that Time : For in Abraham's Time we find it gene- rally eftablifhed. Some will have it to have comm cnce J under Nimrod, becaufe it was he who firft began to make War, and of conlequence to make Captives ; and to brina fuch as he took either in his Battles, or Irruptions, i nt f Slavery.

The Romans called their Slaves Servi, from Servare to keep, fave ; as being fuch as were not killed, but ffaved, to yield Money either by Sale, or by their \y or j. Other Authors are of Opinion, that the Roman Name Serv'i might come from that of Serbi; as that of Slaves from Sclavi, a People. Slavery is abtolutely aboliftied in Eng- land, and France, as to Perfonal Servitude : Our Servants are not Slaves, but only fubject to cettain determinate Setvices, The Moment a Slave fteps on Englifi Ground, he becomes Free.

Slaves make a very confiderable Article of the Traffick in America. The Enghp South-Sea Company have the lo| 6 Privilege of furnifhing the Spanifi Wejl-lmtes with Slaves by Treaty. See Negro. Menage and Voffms derive the Word from Sclavus, which is the Name of a Scythian People, ac- cording to the latter, whom Charlemagne condemned to' per- petual Imprifonment, whence the Italians have made their Schiavo, the Germans their Slaef, and we Slave : But the fotmer will have it the Name of a People whom the Italians and other Nations, uled to buy to make Drudges of- whence the proper Name of a Nation, in Time, became* the Name of a State or Condition.

Among the Romans, when a Slave was let at Liberty, he changed his Name into a Surname; took the Nomen or tprte-nomen of his Mafter ; to which -he added the Ogno- raen or Nick-name he had been called by when a Slavs See Libertin. By the Civil Law, the Power of making Slaves is efteem d a Right of Nations, and follows as a na- tural Confequence of War, The Lacedemonians, fay fbme, or as others fay, the AJJyrians, firft introduced the Practice - which the Romans not only approved of, but even in- vented new Manners of making of Slaves-. For Inftance a Man born Free, among them, might fell his Freedom, and be- come a Slave. This voluntary Slavery was firft introduced by a Decree of the Senate,, in the Time of the Emperor Claudius,, and at length abrogated by Leo. The Romans. had Power of Life and Death over their Slaves which nc. other Nations had ; and even this Severity was 'moderated by 4 the Laws of the Emperors ; and by one of Adrian it was made Capital to kill a Slave without a Caufe. The Slaves were efteemed the proper Goods of their Mafters and all they got belonged to them : But, if the Mafter were' too ctuel in his Domeftic Corrections, he was obliged to fell his Slave at a moderate Price. As Slavery was not abo. liflied by the Gof'pel, the Cuftom of having slaves lafted a long Time in Chriftendom. In the Time of Lotus the Grofs, they were fo numerous in Egypt, that 'twas found a difficult Matter to quell a Body of them who had made Head againft their Mafters : Yet Bartholin, who lived in 1300, obferves, there were none left in his Time

SLEASY Holland, a Kind of Holland thus eall'd be- caufe made in Silefia in Germany; and which from its Slightnefs, occafions all thin, flight, ill-wrought Hollands to be called Sleajy. See Holland.

SLEDGE, a Kind of Machine, or Carriage, without Wheels, for the Conveyance of very weighty Things as huge Stones, Bells, &c. The Dutch have I Kind of Sledge, wheteon they can carry a Veffel of any Burthen by Land. It confitts of a 1 lank a Foot and a Half broad, and the Length of the Keel of a moderate Ship, railed a little be- hind and hollow in the Middle ; fb that the Sides goalit- tle aflope, and are furnifli'd with Holes to receive Puis, &. The reft is quite even.

SLEEP, that State wherein the Body appearing perfVaiy at Reft, external Objects move the Organs of Senfe as du- ally, without exciting the uf'ual Senfations. See Wiring

Sleep, according to Rohault, confifts in a Scarcity of Spirits ; which occafions that the Orifices or Pores of the Nerves in theBtain, whereby the Spirits ufed to flow into the Nerves, being no longer kept open by the Frequency of the Spirits, {hut of themfelves. For this being ilippoM. as loon as the Spirits, now in the Nerves, fliall be difr pated, the Cap.llaments of thofc Nerves, having no Sup- plement of new Spirits, will become lax, and cohere as if cemented together; and fo be unfit to convey any to" preflionto the Brain ; befides, the Mufcles being now void ot Spirits, will be unable to move, or even fuftain the Mem- bers : IhuswillSenfation, and Motion, be both deftroved. See Sensation, Muscular Motion, Spirits,^.'

Sleep is broke oft 7 unnaturally, when any of the Or- gans of Senfe are fo briskly afled on that the Action is propagated to the Brain : For upon this, the fe'.v Spi- ■ nts remaining ,n the Brain, are all called toseihcr, and u-ute their Forces to unlock the Pores of the Nerves, fjc. But if no Objeft fhould thus affect the Oroan, yet Sleep would in fome Time be broke off naturally ; for the Quan- tity of Spirits generated in Sleep, would at length be S>

great,