SLATE CLAY SLAVERY. 



279 



into the composition of slate rocks, they are distin- 

 guished by their green colour, and by their unctuous 

 feel. These are the slates which, for the most part, 

 have talc as an ingredient, and are often called talc, 

 or chlorite slates. When carbonaceous matter pre- 

 vails to the proportion of eight or ten per cent., 

 the slate soils more or less, and even writes. It is 

 then called drawing slate, or black chalk. This 

 variety is softer than the preceding kinds, and 

 sometimes possesses the property of adhering to 

 the tongue. Its specific gravity is only 2-18. A 

 ranety of slate called adhesive slate, from its pro- 

 perty of adhering to the tongue, deserves to be 

 mentioned, although it is very remote in its proper- 

 ties from the roofing slate, which may be considered 

 as the type of the present rock. Fracture in the 

 large slaty ; in the fine earthy ; colour light gray ; 

 specific gravity 2-08; easily broken ; absorbs water 

 with a hissing noise. It consists of 



Silex, 

 Magnesia, 

 Oxid<> of iron, 

 Alumine. 

 Carbon, 

 Water, . 



62-50 



8-o:> 



4-00 

 0-25 

 0-75 

 22-00 



Still another argillaceous aggregate, which has 

 been treated of along Avith the slates, is the polish- 

 ing slate. It differs from adhesive slate in not 

 adhering forcibly to the tongue, in being very soft, 

 and in having a low specific gravity, namely, O50 

 to 0-60. 



Slate, in varieties approaching roofing slate, oc- 

 curs in vast strata in primitive countries, and is 

 often observed graduating into mica slate. Where- 

 ever its strata are contiguous to granite, gneiss, or 

 mica slate, it is noticeable that it has a more 

 shining lustre: as it recedes, however, from the 

 primary rocks, its texture is more earthy. It is 

 commonly divided into beds of various degrees of 

 thickness, which are generally much elevated ; and, 

 from the natural divisions of the rock, they often 

 form peaked and serrated mountains. The cleavage' 

 of these beds is in a transverse direction, making 

 with the slope of the bed an angle of about 60. 

 The finest variety which is used for roof slate 

 seldom forms entire mountains, but is generally 

 imbedded in slate rocks of a coarser kind. Those 

 kinds are selected for the covering of buildings 

 which have the smoothest surface, and split into 

 the thinnest plates. Quarries of slate of this 

 description are worked extensively in Westmore- 

 land, Yorkshire, Leicestershire, North Wales, 

 Cornwall, and Devonshire. Whet slate is found in 

 beds between strata of common slate in transition 

 formations. The use <Jf this variety for hones and 

 whet-stones is well known. The most valuable 

 kinds come from Sonnenberg, in Meiningen, and 

 from Saalfeld. They are likewise brought from 

 the Levant. The drawing slate, which is used as 

 a drawing material, comes from Italy, Spain, and 

 Bayreuth in Thuringia. Adhesive slate occurs only 

 at Menil, Montant, and Montmartre, near Paris. 

 Polishing slate, which is believed to have been 

 formed from the ashes of burnt coal, occurs at 

 Planitz, near Zwickau, and near Bilin, in Bohemia. 

 It is used as a polisher of metals. 



SLATE CLAY. See Clay. 



SLAVE LAKE, OR ATHAPESCO; in North 

 America; lat. 61 20' N. ; Ion. 115 W. It is 

 about 200 miles in length, and fifty in breadth. 



SLAVERY. The history of mankind shows 

 that the empire of force gives way but slowly to 



the empire of reason. It is one of the most inte- 

 resting and useful labours of the historian, though 

 not the most flattering to human pride, to trace 

 the steps by which this change takes place, as 

 exemplified, for instance, in the history of political 

 institutions, the relation of the wife to the hus- 

 band,* and of the servant to the master. At 

 present, we shall confine ourselves to the institu- 

 tion of domestic slavery. This originates in the 

 power of the strong over the weak. Man, in the 

 infancy of society, uses his physical power according 

 to his own pleasure. In the case of his wife and 

 children, natural affection restrains him, in a great 

 measure, from the abuse of his power. But there 

 is another class of dependents, his conduct towards 

 whom is not restrained by such feelings his slaves. 

 Slaves were probably at first captives. It being 

 considered that the victor had a right over the life 

 of the vanquished, the latter was looked upon as 

 altogether at the disposal of the former, who, if he 

 chose to spare him, might subject him to any 

 restraint that he saw fit. The principle on which 

 slavery was thus made to rest, was only adapted 

 to the rudest condition of society, and is wholly 

 inconsistent with the present state of morals and 

 religion. We carry on wars, indeed, for the at- 

 tainment of specific objects, and, as far as the 

 destruction of human life is required for the attain- 

 ment of those objects, we regard it as a necessary 

 evil; but we do not consider that either individuals 

 or governments have any right to dispose of the 

 lives of the vanquished ; nor are even criminals 

 allowed to be made slaves in the full sense of the 

 word. Philosophy allows of no obligation from 

 one man to another without an equivalent ; and 

 the idea of making a man a slave, that is, of sub- 

 jecting all that he has and is to the disposal of a 

 master, who is not bound, on his part, to render 

 any thing in return, is at war with the first princi- 

 ples of bodies politic. Slavery can never be a legal 

 relation. It rests entirely on force. The slave, 

 being treated as property, and not allowed legal 

 rights, cannot be under legal obligations. Slavery 

 is, also, inconsistent with the moral nature of man. 

 Each man has an individual worth, significance, and 

 responsibility, is bound to the work of self-im- 

 provement, and to labour in a sphere for which his 

 capacity is adapted. To give up his individual 

 liberty, is to disqualify himself for fulfilling the 

 great objects of his being. Hence political socie- 

 ties, which have made a considerable degree of ad- 

 vancement, do not allow any one to resign his 

 liberty, any more than his life, to the pleasure of 

 another. In fact, the great object of political 

 institutions in civilized nations, is to enable man 

 to fulfil, most perfectly, the ends of his individual 

 being. Christianity, moreover, which enjoins us, 

 while we remain in this world, to regulate our 

 conduct with reference to a better, lays down the 

 doctrine of brotherhood and mutual love, of " doing 

 as we would be done by," as one of its fundamental 

 maxims, which is wholly opposed to the idea of 

 one man's becoming the property of another. These 

 two principles of mutual obligation, and the worth 

 of the individual, were beyond the comprehension 

 of the states of antiquity, but are now at the basis 

 of morals, politics, and religion. In the most culti- 

 vated states of antiquity, the individual, as such, 

 was little regarded. He was considered only as a 



* In the nrticle Marrinf?e, it is statfld tha^ in almost all 

 original marriage ceremonies, the symbolic expression ol 

 buying and celling s to be found. 



