VOL. XLIV.] PHILOSOPHICAL TRANSACTIONS. 285 



Though mines have not perhaps been discovered near the Lough, there is 

 reason to believe that there are such in its neighbourhood, from the great quan- 

 tity of iron-stones found on its shores, and places adjacent to it, and from the 

 yellowish ochre and clay to be met with in many places near it. Of these iron- 

 stones, which are very ponderous, outwardly of an ocherish yellow colour, and 

 inwardly of a reddish brown, he calcined many, and found the powder of all to 

 yield strongly to the magnet. Gerald Boate* mentions an iron mine, in the 

 county of Tyrone, not far from the Lough, and such others at the foot of Slew- 

 Gallen mountains. 



That mines are generated and found in the bowels of hills and mountains, is 

 obvious to any that have the least knowledge of metallurgy ; and that springs also 

 proceed from mountains, is no less obvious ; therefore should a spring happen in 

 the bowels of any of these mountains to run through a vein of mineral of any 

 kind whatever, it will wash and dilute some parts of such mineral, impregnate it- 

 self with the unctuous, saline, and metallic particles of such mines, and convey 

 them along with its water ; and if in its way, whether under-ground, or at its 

 issuing out of the cliffs of a mountain, of the sides of a river, or of the lake in 

 question; or whether it rises under water, in the middle of such a river or lake in 

 any particular place, and in its course meets with wood, vegetables, or any other 

 lax bodies (lodged in the mud or gravel), whose pores, by the natural heat of the 

 mineral streams, or any other accident, being open and duly prepared, these me- 

 tallic moleculae and saline particles will penetrate through, insinuate and lodge 

 themselves in the pores and vessels of such wood, &c. fill them up, and, by de- 

 grees, turn them into stone ;^ '' There being some of these lapidescent juices of 

 so fine a substance, yet of so petrifying a virtue, that they will penetrate and 

 petrify bodies of very different kinds, and yet scarcely, if at all, visibly increase 

 their bulk, or change their shape and colour." 



That such springs there are, hidden under the water or mud of this lake, will 

 appear probable, from what has been said, and perhaps evident, from the ac- 

 counts since received, that in the great frost of 1740, the lake was frozen over so 

 as to bear men on horseback, yet several circular spaces continued unfrozen. But 

 how the several attempts, made, as mentioned, by Messrs. Molineux, Nevil, 

 and Smyth, to procure wood half-petrified (by fixing stakes of holly in the lake, 

 which received no alteration) proved unsuccessful, the reason I think is plain, 

 because they were not fixed in the proper place, viz. the course or vein of the 

 spring, where nothing but chance could have directed them. This petrified wood 

 is often found in different places on the shores of the lough, but generally in 

 greater plenty when the water has been disturbed by great storms ; which makes 



♦ Nat. Hist, of Ireland, Dub. 1726.— Orig. + Rob. Boyle of Gems, p. 124, 8vo.— Orig_ 



