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. Uvmer of preparing red Morocco. The Skins are fteep'd twenty-four hours in a River, taken our, ftrerch'd on the Leg, beat with the Knife, return 'd into the Water for twenty-four hours, re-beaten on the Leg, re-ftccp'd; thrown into a Far, and for three \Veeks, taken out and re- rurn'd every Morning, to difpbfe them to peel. Being taken out for the kit time, they are fcraped with the Knife, and when the Hair is quite off, thrown in Pails of fre/h Water, where they are rinfed; then the Fle/li-lide fcraped, thrown into the Pails, and thus alternately from the Leg to the Fails, till they leave the Water quite clean: then they are put in lukewarm Water, with the ' Experiment as before, and after twelve hours, rinfed in clear Water, and fcraped on the Leg on both Sides, pounded in Fails, and the Water changed three times ; then wrung and ftretch'd on the Leg, and pafs'd after each other into Water, with Alum diffolved in it. Thus alum'd, they are left to drain till the Morning, then wrung out, pull'd on the Leg, and folded from Head to Tail, the Flefh inwards. In this State they receive their firft Dye, by paffing them after one another into a red Liquor, prepared with Lacca, and fome other Ingredients, kept fecret among the Maroamneers. This they repeat again and again, till the Skins have got their firft Colour. T hey are then rinfed in clear Water, ftretch'd on the Leg, and left to drain twelve Hours; thrown into Water, into which white Galls pulveriz'd have been pafs'd thro a Sieve, and flirred inceffanfly for a day with long Poles, taken out, hung on a Bar a-crofs the Water all night' White againft Red, and Red againft White, and in the Morning the Water flirred up, and the Skins return'd into it for twenty-four Hours.

MARROW, a delicate Subftance contain'd in the Cavities of the Bones. All the Bones of the Body, which have any confiderable Thicknefs, have either a large Cavity, or are fpongeous, and full of little Cells ; in both the one, and the other, is an oleaginous Sub- fiance, call'd Marrow, contain'd in proper Veficles or Membranes, which open into one another. In the larger Bones, this fine Oil, by the gentle Heat of the Body, is exhaled thro the Pores of its fmall Bladders, and enters fome narrow Paffages, which lead to fome fine Canals, ex- cavated in the Subftance of the Bone, according to its Length ; and from thefe, other crofs Paffages (not directly oppofite to the former, left they fhould weaken the Bone too much in one Place) carry the Marrow ftill farther in- to more longitudinal Canals, placed nearer the Surface of the Bone : All this Contrivance is, that the Marrow may fupple the Fibres of the Bones, and render them lefs apt to break. The Antients imagin'd, that Mi>rozii*ferv'd for Nourimment to the Bones. But later Obfervations have found Blood-Veffels in the Bones ; fo that it appears the Bones are nourifh'd in the fame manner as the other Parts of rhe Body. Befides, we find many Bones which grow, and yet have no Marrow in them ; witnefs the Horns of Deer, Lobfters Claws, £i?c. See Medulla.

MARS, among Chymifts, fignifies Iron, becaufe ima- gin'd under the Influence of that Planer. See Iron. Phy- sical Writers prove Iron preferable for all Medicinal Pur- pofes to Steel, which is only a more harden'd, compact. Iron, made fo by Art 5 whereby it is rendred more unfit to yield thbfe Principles or Parts in Preparation, which the Phyfician requires to be drawn out. For the Opera- tion of its Medicinal Properties, fee Chalybeat.

MARS, in Aftronomy, one of the five Planets, and of the three fuperior ones ; its Place being between the Sun and Jupiter : See Planet, and System. Its Character is $. Its mean Diftance from the Sun is 1 524 of thofe Parts, whereof the Diftance of the Sun from the Earth is 1000. Its Excentriciry 141. The Inclination of its Orbit, that is, the Angle form'd by the Plane of its Orbit with the Plane of the Ecliptic, 1 Deg. 52 Min. The periodical Time, in which it makes its Revolution round the Sun, 680" Days 25 Hours. Its Revolution about its own Axis is perform'd in 24 Hours 40 Minutes. For the Diameter of Mars, fee Diameter, and Semidi ameter. For its Denfity, fee Density. For the Force of Gravity on its Surface, fee Gravity. Its Parallax, according to Dr. Hook and Mr. Flamjlead, is fcarce 2.0 Seconds.

In the Achronical Riling of this Planet, that is, when it is in oppoiitfon to the Sun, it is found twice as near the Earth as the Sun ; which is a Phn:nomenon that has ex- tremely difcredited the Ptolemaic Hypothefis^ Dr. Hook-, in 1665, obferv'd feveral Spots in Mars, which having a Motion, he concluded the Planet to turn round ifs Centre. \r\ 1666, M. Cajjjni obferv'd feveral Spots in the two Faces or Hemifpheres of Mars, which, by continuing his diffe- rent Obfetvations very diligently, he found to move by little from Eaft to Weft, and to return in the fpace of 24 Hours 40 Minutes to their former Situation. Whence both the Motion and Period, or natural Day of that Pla- net, was determin'd. Mars always appears with a ruddy,

troubled Light; whence we conclude it is cncompafs'ct with a thick, cloudy Atmofphere, which, by difturbing the Rays of Light in their Paffige and Re-paffage rhro it, occafion that Appearance. Mars having his Light from the Sun, and revolving round it, has an Increafe and De- crcale like the Moon. It may alfo be obferved almoft biflected, when in its Quadratures with the Sun, or in his Periga:on, but never corniculated or falcated, as the infe- rior Planets. See Phases.

This Planet's Diftance from the Sun, is to the Diftance of the Earth and Sun, as i± to 1. So that a Man placed in Mars, would fee the Sun's Diameter lefs by one third than it appears to us, and confequently the Degree of Light and Heat, which Mars receives from the Sun, is lefs by one third than that received by rhe Earth : This Propor- tion, however, will admit of a fenlible Variation, on ac- count of the great Excentricity of this Planet.

Tho the Period or I ear of this Planet, as has been al- ready obferved, is nearly twice as long as ours, and his natural Day, or the Time in which the Sun appears above his Horizon (fetting afide the Confideration of Twilight) is almoft every where equal to his Night ; yet it ap- pears, that in one and the fame Place on his Surface, there will be but very little Variety ofSeafons, fcarce any Difference of Summer and Winter. And the reafon is, that the Axis of his Diurnal Rotation is nearly at right Angles with the Plane of his Orbit. Ir will be found, notwithstanding, that Places fituate in different Latitudes, that is, at different Diftances from his Equator, will have very different Degrees of Heat, on account of the diffe- rent Inclination of the Sun's Rays to the Horizon ; as 'tis with us, when the Sun is in the Equinoxes. From this Confideration, Dr. Gregory endeavours to account for the Appearance of the Fafcia? in Mars; which are certain Swathes or Fillets feen in this Planet, and pofited paral- lel to his Equator. For, as among us, the fame Climate has at different Seafons very unequal Degrees of Heat ; but in Mars it is otherwife, the fame Parallel having al- ways a pretty equable Degree of Heat : It follows, that thefe Spots may probably be form'd in Mars, or his At- mofphere, as Snow and Clouds are in ours, -viz. by the conftant different Intentions of Heat and Cold in the diffe- rent Parallels ; and fo come to be extended in Circles or Belts parallel to his Equator, or the Circle of his Diurnal Revolution. And this fame Principle may, perhaps, folve the Phenomenon of Jupiter's Belts ; that Planet, likeMtn, having a perpetual Equinox. See Jopiter.

Befides the ruddy Colour of Mars, we have another Ar- gument of his being incompafs'd with an Atmofphere; and it is this, That when any of the fix'd Stars are feen near his Body, they appear extremely obfeured, and al- moft exftinfl. If this be the Cafe, an Eye placed in Mars would fcarce ever fee Mercury, unlefs perhaps in the Sun at the time of Conjunction, when Mercury paffes over his Disk, as he fometimes appears to us in form, of a Spot. A Spectator in Mars will fee Venus about the fame Dif- tance from the Sun rhat Mercury appears to us ; and the Earth about the fame Diftance from the Sun, that to us Venus appears. And when the Earth is found in Conjunc- tion with, and very near the Sun, he will fee in Mars what Caflni faw on Earth, mm. the Earth appear horned or fal- cated, and its Attendant the Moon of the fame Figure, and at its utmoft Diftance from the Earth, not above 15 Minutes of a Degree.

Maks, among the Aftrologers, is held a Malific Planet. They call it the little Unfortunate ; it is mafculine, noc- turnal, hot and dry.

Games of Mars, were Combats inftituted atRome in ho- nour of the God Mars. They were held twice in the Tear; once in the Circus, on the 4th of the Ides of May; and a fecond time on the ift of Augujt. Thefe were efta- bli/h'd, fome time after the firft, in memory of the Dedi- cation of the Temple of Mars on that Day;

Thefe Games confifted in the Courfes of Horfes, and Combats with wild Beafts. Germanicus is faid to have kill'd two hundred Lions in the Circus on thefe Occa- sions.

Crocus Martls, is the Ruft of Iron ; or Iron in an impalpable Powder. The Alchymifts fometimes call their Mercury by the Name of Mars.

MARSHAL: With us there are feveral Officers of' this Name, the Chief whereof is the Earl-Marfial of Eng- land, who is one of the Great Officers of the Crown. Ha takes Cognizance of all Matters of War and Arms', de- termines Contracts touching Deeds of Arms out of the Realm upon Land, and Matters concerning War within the Realm, which cannot be determin'd by Common Law, in which he ufually proceeds according to the Civil Law. This Office is Hereditary, having been for many Ages in the Houfe of Norfolk. 1 S

The Earl-Mar%ui had antiently feveral Courts under him, but hath now only the Marfialfea, where he may fit