362 



A. D. 1200. 



tricks with it, to the great amazement of the ignorant, who afcribed 

 the wonders they faw^ to the power of magic. But till about the end 

 of the twelfth century we find no good authority to fhow, that the more 

 valuable property of the magnet, its polarity, or that power, (I had 

 almoft faid inftind) by which one point of it, or even of a needle or 

 bar of iron or fleel touched with it, turns to the north pole, and the 

 oppofite point to the fouth, was known, at leafl in the weftern parts of 

 the world. 



About the conclufion of the twelfth century the earlieft notice, I be- 

 lieve, to be found of the polarity of the magnet appears in the poetic- 

 al works of Hngues de Bercy, called alfo Guiot de Provins, who fays, 

 ' This (polar) ftar does not move. They (the feamen) have an art, 

 ' which cannot deceive, by virtue of the manete, an ill-looking brownifh 



* flone, to which iron fpontaneoufly adheres. They fearch for the right 

 ' point, and when they have touched a needle on it, and fixed it on a 

 ' isit of ftraw, they lay it on the water, and the ftraw keeps it afloat. 



* Then the point infallibly turns toward the ftar ; and when the night 

 ' is dark and gloomy, and neither fhar nor moon is vifible, they fet a 

 ' light befide the needle, and they can be affured, that the ftar is op- 

 ' pofite to the point ; and thereby the maiiner is direded in his courfe. 

 ' This is an art, which cannot deceive *.' \Guiot, op. Fauchet, Recueil 

 de la langue et poefie FranfaiJ'e, p. 555.] 



Jacques de Vitry (or Jacobus de Vitriaco) who alfo flourifhed at this 

 time, and was bifliop of Aeon in Paleftine, wrote three books of the 

 hiftory of the Eaft and the Weft, wherein he employs ten chapters [L. 

 i, cc. 84-93] ^"^ gi'^i^g "^"^ account of the natural produdions of the Holy 

 land and other Oriental countries ; and his defcriptions, compared with 

 thofe of Pliny, exhibit a deplorable proof of the decay of fcience in 

 Europe during the courfe of eleven centuries. In his account of the 

 pretious ftones of the Eaft [L. i, f. 91] he confounds the adamant or 

 diamond with the magnet as follows. ' The adamant is of a light iron 

 ' colour, about as big as the kernel of a filbert nut ; and though it is 

 ' fo hard as to refift the force of any metal, it may be broken by the 



* frefh blood of a ram-goat. Fire does not make it hot. It attrads 

 ' iron to it by fome hidden quality. An iron needle, after it has touch- 

 ' ed the adamant, conftantly turns to the north ftar, which, as the axis 



* of the firmament, remains immoveable while all the others revolve 



* around it ; and thence it is indifpenfihly necejfary to all thofe who fail on 

 ' the/ea. If placed near a magnet, which has attraded a piece of iron, 



* The old French of the original is varioudy veiicc for my lale worthy friend Do£lor Lorimer, 



corrupted in the manufcripts and the edition. Tlie and is inferted in his Cvitcij'e cffay on mtignttifm, ? 



bed literal tranflation, which I have nearly follow- work publiflied after his death, 

 cd, is that, which was made by a native of Pre- 



