Chemical Science, 339 



contact 6i air, It equally took place ^^lien stirred ; being, how- 

 ever, very hygrometric, the effect soon went off if the powder 

 were exposed to air. Excited in a silver capsule, and then left 

 out of contact of the air, the substance remained electrical a 

 great length of time, proving its very bad conducting power ; 

 and in this respect surpassing, perhaps, all other bodies. The 

 effect may be produced any number of times, and after any num- 

 ber of desiccations of the salt. 



Platina rubbed against the powder became negative — the pow- 

 der positive ; all other metals tried, the same as platina. When 

 rubbed with glass, the glass became strongly negative, the oxa- 

 late positive, both being dry and warm ; and indeed this body ap- 

 pears to stand at the head of the list of all substances as yet 

 tried, as to its power of becoming positively electrical by friction. 



Oxalates of zinc and lead produced none of these effects. — ^M. F, 



«. Course of Lightning on and under the surface of Ground. — 

 On the 28th of May, 1824, the lightning fell upon a tree, about 

 a foot in diameter, standing one or two hundred yards from 

 the house of Ephraim Tucker, in Vernon County. The fluid left 

 few marks of its course down the tree, but tore up the earth very 

 much at the foot of it ; and made, in one direction, a furrow, 

 eight or ten feet in length, by following a root that ran three or 

 four inches below the surface, and throwing off the turf in ragged 

 portions. No other effects of the fluid were to be seen near the 

 tree. At the distance of thirty feet from the tree runs a post 

 wall, bounding the meadow, and separating it from the highway; 

 a low wall of small stones, surmounted by two rails, supported 

 by posts standing in the wall. In the highway, near the wall, 

 at this place, begin to appeatr marks of the passage of the fluid 

 below the surface. The sod, in some places, seemed to be a little 

 raised along the line of its course towards the road. The road 

 here is formed in the middle of a highway, sixty-six feet wide, as 

 turnpike roads are commonly built, by raising a path twenty feet 

 wide, or more, with earth, taken from the edges of it, which are 

 thus sunk so as to form ditches, commonly four or five feet wide, and 

 one or two feet deep. From the wall to the ditch, and across 

 the road and ditch, tlie fluid certainly passed under ground, and 

 almost in a straight line. Before reaching the ditch it passed 

 under a thick bunch of bushes, forming a matted bundle of roots 

 and earth, two or three feet in diameter, and raised a little above 

 the adjoining surface. In coming from beneath this cluster of 

 bushes, which stood near the ditch, the fluid came so near the 

 surface, as to throw off considerable lumps of earth from the side 

 of the ditch, and raise and crack the surface all along its course 

 across the bottom of it. It does not seem to have come out 

 of the ground here, but continuing under ground, it went 



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