rre B L E 
tepted, juft as fifon rendered magnetic has an aiftion di- 
feded from fbuth to north. The adion of red metals is 
more palpable than that of the white; but the latter, 
though weaker, has neverthelefs a real exiftence in the 
fulphur. In the fupplement to this memoir, there is an 
accurate account of the precedes that have furnifiled thefe 
invariable re Cults. They will naturally fugged, fays our 
author, the idea of conftructin'g an electrical compafs, 
which may be of as eminent ufe in experimental philofo- 
pby as the magnetic compafs is in navigation. The natural 
and fpontaneous direction of metallic emanations towards 
the weft being ascertained, it only remains to render them 
palpable by the conftrudlion of an inftrument which may 
be fubftituted in the place of the electrometrical twig that 
goes vulgarly by the name of the divining rod. 
■ His analyfis of the hot fprings of Bourbon-Lancy, to 
the fource of which in the great mountains of Burgundy 
lie was led by the eledrical fenlations of Bleton, fliows 
the great intelligence and fagacity of our author in opera¬ 
tions of this nature. He found the origin of thefe famous 
hot fprings in the centre of an oblong rifing ground, full 
of coal, and commanded on three fides by a group of 
mountains, of which the greateft part was filled with the 
fame mineral. From a particular cafe, here circumftan- 
tially defcribed, in which the eledrical rays of the fubter- 
raneous water and thofe of the adjacent coal croifed each 
other, our author deduces a very natural account of the 
errors which may (ometimes, though rarely, miflead for a 
time the greateft adepts in bletonifm, when they find 
themfelves in combined fplieres of electrical adivity. 
Another obfervation, which fee ms confirmed by feveral 
fads, accounts farther for this fallibility : the obfervation 
is, that eledrical rays, whether direct or collateral, itfuing 
from fubterraneous fotufes, feem to undergo in certain 
cafes a fort of refradion as they pafs from one medium to 
another, or travefe bodies which differ with refped to the 
property of tranfmitting this eledricity. In a word, it 
follows from thefe obfervations, that when fuch privileged 
iri.veftigators of currents or minerals as Bleton are placed 
upon the eledrical fplieres of thefe bodies, they will in¬ 
dicate their fituation and their refpedive depths according 
to the impreftions they feel within themfelves, or the mo¬ 
tions they obferve in the eledrometrical inftruments which 
they employ : and, if they meet with fecond accidental 
caufes or complications of electrical fplieres, which mo¬ 
dify or alter thefe methods of trial, this will neceftarily 
occafion miftakes in the refults of their operations which 
they may probably red ify ; but which, at all events, it 
would be unjuft to lay to their charge, or allege as an ob- 
jedion againft the reality of their talent. 
BLETTERANS', a town of France, in the department 
of Jura, and chief place of a canton, in the diftrid of 
Lons-le-Saunicr : fix miles north-weft of Lons-le-Saunier. 
BLE'TljJ,/. [from ( 3 a.?Au, toftrike.] Suddenly (eized, 
as w ith a fuffocation, and having the appearance of having 
been fmitten with a flick. 
BLE'VIO, a town of the country of the Grifons : 
twelve miles foutli-eaft of Furftenau. 
BLE'VY,' a town of France, in the department of the 
Eure and Loire : three leagues fouth-fouth-weft of Dreux. 
BLEW, the preterite from blow .—The reft fled into a 
ftrong tower, where, feeing no remedy, they defperately 
ikxv up themfelves, with a great part of the caftle, wit-h 
gunpowder. Knolles. 
BLE'XEN, a town of Germany, in the circle of Weft, 
phalia, and county of Oldenburg: thirty miles nortli- 
north-eaft of Oldenburg. 
BLEY'MARD, a town of France, in the department 
of the Lozerre, and chief place of a canton, in the diftrid 
of Mende : three leagues and a half eaft of Mende. 
BLKYME, f. An inflammation in the foot of a horfe, 
between the foie and the bone. 
BLEYS'WELCH, a town of Germany, in the circle 
of Weftphalia, and biftiopric of Paderburn : four miles 
fouth of Wunnenberg. 
B L I 
BLEVS'WICK, a town of Holland : eight miles north 
Of Rotterdam. 
BLIGH’s CAP, a fmall ifland on the fouthern Pacific 
Ocean, near Kerguelen’s Land. Lat. 48. 29. S. Ion. 68r 
40. E. Greenwich. 
BLIGHT, /, [the etymology unkown.] Mildesv, ac¬ 
cording to Skinner ; but it fee ms taken by molt writers, 
in a general fetife, for any Caule of the failure of fruits. 
Stridly fpeaking, it is a difeafe incident replants; of 
which Dr. Martyn, Regius Profeffor of Botany iii the 
univerfity of Cambridge, gives the following particulars 
in bis new edition of Miller’s Botanical Didionary. 
Blights are often canfed by a continued dry eafterl/ 
wind for feveral days together, without the intervention 
of fliowers, or any morning dew, by which the perfpira- 
tion in the tender blolfoms is flopped, fo that in a ftiort 
time their colour is changed, and they wither and decay ; 
and, if it fo happen that there is a long Continuance of 
the fame weather, it eqtially affeds the tender leaves; for 
their perfpiring matter is hereby thickened and rendered 
glutinous, clofely adhering to the furface of the leaves, 
and becomes a proper nutriment to thofe fmall infeds, 
which are always found preying upon the leaves and 
tender branches of fruit trees, whenever this blighf 
happens; but it is not thefe infeds which are the fir ft 
caufe of blights, as hath been imagined by fome ; though 
it mud be allowed, that, whenever thefe infeds meet with 
fuch a proper food, they multiply exceedingly, and are in- 
ftrumental in promoting the diftemper; fo that many 
times, when the feafon proves favourable to them, and no 
proper care has been taken to prevent their mifehief, ft is 
furprifing to think how whole walls of trees have fuffered 
by this infedion. The beft remedy for this diftemper is, 
gently to wafli and fprinkle over the trees, from time to 
time, with common water, (that is, fuch as has not had 
any thing deeped in it;) and the fooner this is performed 
(whenever we apprehend danger) the better; and, if the 
young and tender (hoots feem to be much infeded, wa(h 
them with a woollen cloth, fo as to clear them, if poftible, 
from all this glutinous matter, that their refpiration and 
perfpiration may not beobftruded ; and if we place fome 
broad flat pans or tubs of water near the trees, that the 
vapours exhaled from the water may be received by the 
trees, it will keep their tender parts in a dwdile ftate; and 
greatly help them; but, whenever this operation of wafh- 
ing the trees is performed, it fhould be early in the day, 
that the moifture may be exhaled before the cold of the 
night comes on; efpecially if the nights are frofty : nor 
fhould it be done when the fun fhines very hot, which 
would be fubjed to fcorch up the tender blcftfoms. 
Another caufe of blights in the fpring is, (harp hoary 
frolls, which are often fucceeded by hot fun-fhine in the 
day-time ; this is the rnoft hidden and certain deftroyer of 
fruits that is known ; for the cold of the night ftarves the 
tender parts of the blotfoms, and, the fun rifing hot upon 
the walls before the moifture is dried from the bloffoms, 
(which, being in a fmall globules, colleds the rays of the 
fun,) a fealding heat is thereby acquired, which fcorches 
the tender flowers, and other parts of plants. The me¬ 
thod to prevent this mifehief is to cover the walls care¬ 
fully with mats, canvds, or reeds, fattened fo as not to be 
difturbed with the wind, and fuffered to remain on during 
the night, but taken off every day, when the weather 
permits. Although this method is thought by fome to 
be of little fervice; and may be really prejudicial, if the 
trees be too long covered, or incautioufly expofed ; yet 
when this covering is conducted properly, it frequently 
proves a great protection to fruit-trees ; and if the cover¬ 
ing be fixed near the upper part of the v ail, and be faf- 
tened to pullies, fo as to be drawn up or let down occa- 
fionally, the operation will be eafy, and the fuccefs will 
fufficiently repay the troublp. 
There is another fort of blight that fometimes happens 
later in the fpring, namely fin April or May, which is 
often very deftrubtive to orchards, and open plantations, 
againft 
