SCR 



S C K, 



boiling. The (hells of fea-fi(h have great affinity in their 

 fubftance and nature with this, both being powerful alkalies, 

 and both ealily calcining into lime. 



The magnefia alba, fo celebrated in Germany for its 

 mild purgative and alkaline virtues, feems very nearly allied 

 to this earth ; and it is probable, according to Hoffmann, 

 that the purging virtues of many fprings are owing to the 

 quantities they contain of this fubltance. 



SCRATCHES, among Farriers, a diftemper incident 

 to horfes, confilling of dry fcabs, chops, or rifts, that 

 breed between the heel and the paftern joint. 



There are various kinds of fcratches, diftinguilhed by vari- 

 ous names, as crepances, rat-tails, mules, kibes, pains, &c. 

 which are all fo many fpecies of the fame malady, engen- 

 dered from fome hot humours falling on the legs, or from 

 the fumes of the bealt's own dung lying under his heels, 

 or near them, or for want of rubbing his heels, efpccially 

 after a journey, from over-hard riding, &c. 



The diforder begins firll with dry fcabs in the pallern 

 joint, in feveral forms. It is known by the Itaring, dividing, 

 and curling of the hair on the part. For the cure of this 

 diforder, fee Grease. 



In order to prevent it, the heels (hould be kept fupple 

 with curriers' dnbbmg, which is made of oil and tallow : 

 by ufing: this precaution before exercife, and wafhing the 

 heels with warm water when the horfe comes in, the fcr3tche9 

 will be prevented. 



SCRATCHPANS, in the Engliih SaU-Worh, a name 

 given to certain leaden-pans, which are ufually made about 

 a foot and a half long, a foot broad, and three inches deep, 

 and have a bow, or circular angle of iron, by which they 

 may be drawn out with a hook, when the liquor in the pan 

 is boil:ng See Salt. 



Tile ufe of thefe pans is to receive the fcratch ; and thefe 

 pans being placed at the corners of the falt-pan, where the 

 heat is leall violent, catch it as it fubfides there. 



SCRATCH-WORK, Soraffiata, a way of paint- 

 ing in fre co, bv preparing a black ground, on which is 

 laid a white plaller ; which white being taken off with an 

 iron bodkin, the black appears through the holes, and ferves 

 for fhadows. 



This kind of work is lading; but being very rough, it 

 is unpleafant to the fight. It is chiefly ufed to embellifh 

 the fronts of palaces, and other magnificent buildings. 



SCRAWLY, in Agricuhure, a term provincially figni- 

 fying thi'i and ravelled as grain. 



SCREAMER, in Ornithology. See Palamadea. 



SCREEN, an inftruraent for keeping off the wind, or 

 the heat of the fire. 



Screen is alfo ufed for a frame of laths to fift earth, 

 fand, gravel, &c. 



Screen, or Screen- Machine, in yfgrica/ture, a fimple con- 

 trivance, invented for the piirpofe of clearing grain of dif- 

 ferent kinds, of various injurious forts of feeds, by pafling 

 it through it. It confifts of a wooden frame, which has 

 ledges o;i the fides, with a fort of hopper in the upper part 

 of it, to which is attached a kind of valve, that moves to 

 fultable diltaiices by means of a fcrew, for letting proper 

 quantities of grain pafs down upon a fquare wire fieve, 

 which is fixed btlow in the frame, and communicates with 

 the hopper in fome meafure. The fcreen ftands up in a 

 floping pofition by means of a leg, that draws out behind 

 it, and which is commonly regulated by a cord, while the 

 operation of fcreening or clearing the grain is going on. 

 It is a very ufeful and convenient machine on fmall arable 

 farms, but on large ones the work is now ufually done 

 hf a fotnewhat fitcilar contrivance in the thrcflung ma- 



chine, while that is going on with it. See Threshing 

 Machine. 



ScREES-Fences, fuch fences as are ralfed for the pur- 

 pofe of affording (heiter from wind"!, lloriiis, &c. The writer 

 of the trait on improving landed eitates fuggelts, that for 

 the purpofe of (belter to pafturing (lock, a tall impervious 

 fence is nearly equal to a depth of coppice-wood, and infi- 

 nitely preferable to an open grove of timber-trees ; befidcs 

 its additional ufe as a fence, or means of inclofnre. And 

 that there appears to him to be only one kind of fence 

 which is properly adapted to this purpofe, which is that 

 of the coppice mound hedge of Devon(hire and South 

 Wales ; and which confifts in a high wide bank or mound 

 of earth, planted with coppice-woods. This becomes, im- 

 mediately on its ereftion, a (belter, and a guard to pailure- 

 grounds round which it is formed. 



And in refpcc\ to the method of forming fences with this 

 intention, it is that of carrying up long piles of earth, be- 

 tween two fod-facings, battering, or leaning fomewhat in- 

 ward, to the required height ; and pianting on the top the 

 roots and lower (tems of coppice-plants, gathered in woods 

 or on watte grounds, or with nurlery plants adapted to the 

 given fituation. If the mound be carried to a full height, 

 as five or fix feet, and about that width at the top, and this 

 be planted with Itrong plants, with llems cut off about two 

 feet above the roots i^in the ufual practice of Dcvonihire), a 

 lulficient fence is thus immediately formed againlt ordinary 

 (tock ; but if the bank be lower, or if nurfery plants be put 

 in, a flight guard run along the outer brink, on either fide, 

 and leaning outward over the face of the mound, is, he ob- 

 ferves, required (efpeclally againlt Iheep), until the plants 

 get up. But where a hedge of this kind is ralfed as a plant- 

 ation. fence, (elpecially on the lower fide of a (lope,) the 

 outer fide only requires to be faced with fods ; the hedge- 

 plants being fet in a rough (helving bank, on the inner fide 

 of the fence. 



Further, with refpeA to the fpecies of hedge-woods pro- 

 per for mound fences, they depend entirely, he thinks, on 

 the foil and fituation. On mounds of bad foil, in a bleak 

 fituation, he has leen the furze alone affording much (heiter, 

 and a good fence. The fides being kept pruned, fo as to 

 (hew a clofe firm face rifing above the top of the bank, it 

 was a fecure barrier, even againft the wilder breeds of Wel(h 

 fheep. The beech is commonly planted in high expofed 

 fituations ; and in places more genial to the growth of wood» 

 the hazel, the a(h, and the oak are the ordinary plants of 

 hedge mounds. The willow tribe have a quality which 

 recommends tliem in fituations where they will flourilh ; they 

 grow freely from cuttings, or truncheons fet in the ground ; 

 whereas to fecure the growth of ordinary coppice- woods, 

 rooted plants are required. The fallow (J'alix caprea) will 

 grow in high and dry fituations, in a m^Lii^-r fo as to be 

 ufeful in this fort of bufinels. And It may be further no- 

 ticed In regard to this defcription of fences, that on thin 

 foiled (tony furfaces, tall mounds are difRcult to raife ; and, 

 there, ftone walls are not only built at a fmall expence, 

 but are convenient receptacles for the (tones with whi^h the 

 foil is encumbered. But a Hone wall, unlefs it be carried up 

 to an inordinate height, at a great expence, is, he conceives, 

 ufelels as a fcreen-fence, and is faid to be dangerous as fuch 

 in a bleak, expofed fituation ; for as loon as the drifting 

 fnow has reached the top of the wall, on the wir.dward fide, 

 it pours over it, and inevitably buries the (heep which may 

 be feeking for (heiter, on the leeward fide. It is therefore 

 conceived, that it is neceliary that a (tone fence (hould be 

 backed with a fcreen-plantation, in order to rend«r it more 

 fafe and effectual for the purpofe. 



10 It 



