278 



SKORODITE SLATE. 



the black colour of the rete mucosum. The fat i 

 keeps the epidermis soft, and is diminished in 

 quantity in those diseases in which the skin becomes 

 rough. The epidermis protects the terminations ot 

 the nerves, whose sensibilities would otherwise 

 soon become blunted. The surface of the skin IB 

 marked with very regular furrows, running parallel 

 with each other, in which are the pores, which ex- 

 hale an attenuated vapour. The proper skin forms 

 a compact and thick membrane, which envelopes 

 the muscles and fat. On being boiled in water, it 

 yields a quantity of gelatinous matter, which is used 

 for making glue. 



SKORODITE is a rare mineral, found in baxony, 

 Carinthia and Cornwall. It presents itself in small 

 crystals, derived from a right rhombic prism of 

 120, but which are terminated at each extremity 

 by foursided pyramids. It is also found massive, 

 and in botryoidal masses, composed of crystals, 

 diverging from a common centre. Its colours are 

 various shades of green; lustre vitreous; streak 

 white ; rather brittle ; hardness about that of fluor. 

 Before the blow-pipe, it emits an arsenical odour, 

 and melts into a reddish-brown scoria, which acts 

 upon the magnetic needle. It consists of 



Arsenions acid, . . 31*40 



Sulphuric acid, . .1-54 



Water, .... 18-00 



Protoxide of iron, with magnesia, lime, and) .-.gg 

 manganese, . . f 



(cranium} ; the bony box which con- 

 tains the brain. It forms the forehead, and every 

 part of the head, except the face. It consists of 



eight bones See the treatise on Animal Mechanism 



in the Library of Useful Knowledge, and Blumen- 

 bach's Manual of Comparative Anatomy (translated 

 into English, 2ded.,by W. Coulson, London, 1827). 

 See, also, the article Phrenology. 



SKULL-CAP (scutellaria) ; a genus of labiate 

 plants. They are herbaceous, with opposite leaves ; 

 and the flowers, also, opposite, and placed in the 

 axils of the superior leaves, sometimes forming 

 terminal spikes, from the diminished size of these 

 leaves. The calyx is entire ; the upper lip vaulted, 

 closing like a lid after the flowering is over. When 

 inverted, the calyx presents the figure of a helmet 

 with the visor raised. The flowers are much longer 

 than the calyx, and usually of a blue colour. The 

 S. lateriflora has been much celebrated as a remedy 

 for hydrophobia; but its pretensions seem to be 

 destitute of the slightest foundation. The stem 

 divides from the base into numerous opposite weak 

 branches, provided with oval acute petiolate and 

 toothed leaves ; the flowers are small and blue, 

 situated at the summits of the branches, and usually 

 turned to one side, by which character it is readily 

 distinguished from the other species. 



SKUNK (mephitis putorius} ; a carnivorous quad- 

 ruped, allied to the weasel and badger, inhabiting 

 most parts of North America, and celebrated for 

 the intolerable stifling stench which it discharges 

 when threatened with danger, and which is its de- 

 fence against its enemies. At other times, the 

 animal is not at all unpleasant, and, if killed while 

 unsuspicious of danger, the offending glands being 

 carefully removed, the flesh may be eaten, and is 

 said to be well flavoured ; in fact, it is frequently 

 made use of, and is much relished by the Indians 

 and hunters. The skunk is about as large as a 

 cat. The dentition differs but slightly from that 

 of the weasels. The upper lip is furnished with 

 long whigkft-s ; the fur is long and thick, composed 



of silky and woolly hairs intermixed ; the colour is 

 white and blackish-brown, in large masses, but the 

 respective distribution of these tints varies so 

 greatly that no two individuals are to be found 

 precisely alike. A second species inhabits South 

 America, and perhaps there are others. The genus 

 is exclusively American. The skunk is a nocturnal 

 animal, and leaves its burrow in the twilight in 

 search of small quadrupeds, and the young and eggs 

 of birds, on which it feeds. When it gains an ( -, 

 to the poultry yard, it often does much mischief. 

 The skunk seems to be perfectly aware of its powers 

 of defence, and takes no pains to avoid man or other 

 animals ; it seems so unsuspicious of danger as to 

 invite attack, and strangers often pay the price of 

 experience. Should a dog attempt to seize him, 

 he is utterly discomfited, and runs away howling, 

 and endeavouring to thrust his nose in the ground. 

 The offensive fluid is ejected to a considerable dis- 

 tance, and is very acrimonious ; the smallest drop 

 is sufficient to render clothes detestable to the 

 wearer and his companions for a great length of 

 time, and without any perceptible diminution in in- 

 tensity. Washing, smoking, baking, burying, in 

 short, every process seems to be ineffectual for its 

 removal. 



SKUNK-CABBAGE (symplocarpus fcetida). 

 Among the earliest of the American spring flowers, 

 often, indeed, before them all, appear the large, 

 thick, purplish and spotted spathes of this plant. 

 The leaves are later in making their appearance, are 

 very large, and bear no inconsiderable resemblance 

 to those of the cabbage. The whole plant has a 

 very strong odour, singularly like that of the skunk, 

 but not comparable to it in.intensity. The skunk- 

 cabbage is unknown in the Southern States. It be- 

 longs to the natural family aroidece. 

 SKYE. See Hebrides. 

 SLANDER. See Libel. 



SLATE. Clay slate (Than Schiefer of the 

 Germans) and argillite. By the early English 

 geologists, this rock was called argillaceous schis- 

 tus, and it is denominated phyllade by the modern 

 French writers. The structure of slate is emi- 

 nently foliated or schistose, separating, in some of 

 its varieties (as in the roofing slate, for example), 

 into lamina? as thin as pasteboard. Prevailing 

 colour gray of various shades: it is also bluish, 

 reddish, and greenish; opaque and dull; yields to 

 the knife, but varies considerably, as respects hard- 

 ness, in its different varieties; fissile; specific, 

 gravity 2-7. When moistened, it emits an argilla- 

 ceous odour. The common roofing slate appears 

 to consist very nearly of the following ingredi- 

 ents: 



Silex, 



Alumine, 



Oxide of iron, 



Potash, 



Magnesia, 



Carbon, 



Water, 



48-00 



2550 



11-30 



470 



1-60 



30 



7-60 



But slate varies exceedingly in its chemical consti- 

 tution, as might very naturally be expected, since 

 it is a mixed rock, consisting of very minute indi- 

 viduals of quartz, feldspar, and mica, to which are 

 occasionally added scales of talc, and particles of 

 carbonaceous matter. Those slates which contain 

 a large proportion of quartz, are called whet-slate. 

 In these, the mechanical composition is impalpable, 

 and the fracture splintery in the small, though slaty 

 in the large. They are translucent, and of a green- 

 ish-white colour. When magnesia enters largely 



