OF MAGNETISM TO DIAMAGNETISM. 381 



the line of the apices of the poles, the equatorial position was 

 exchanged for the axial, in which it was distinctly retained even 

 at an elevation of 54 millim. Again, when the two apices of the 

 poles were separated 55 millim. from each other, on suspension 

 in the centre between them, it became axial ; but when suspended 

 at a third of the distance, it assumed an equatorial position. 

 The latter observation, that the same body, the apices of the 

 poles being the same distance apart, but in different parts of 

 this distance, reacted at one time like a magnetic, at another 

 like a diamagnetic body, might have been anticipated from our 

 view. 



11. A piece of dry apple-trecwood and two pieces of deal, 

 cut in different directions, and placed between the apices of the 

 poles approximated to 17 millim., were more strongly diamag- 

 netic than the charcoal ; but, when raised, arranged themselves 

 distinctly, but slightly, like a magnetic body. 



A cylindrical piece of lump-sugar, 19 millim. in length and 8 

 millim. in thickness, exhibited the transition fi'om the equatorial 

 to the axial position perfectly. 



12. A fresh last year's shoot of an almond-tree, 15 millim. in 

 length, the apices of the poles being 16 millim. apaii;, was dia- 

 magnetic, and remained so at all elevations ; its entire bark was 

 also diamagnetic, but at an elevation of 24 milhm. rotated into 

 the magnetic position. 



A last year's shoot of a cypress-tree, 16 millim. in length, 

 was diamagnetic at every elevation; the entire bark was the 

 same. But the brown external bark alone was decidedly mag- 

 netic, as long as it could oscillate between the two apices of the 

 poles*. 



When the apices of the poles were approximated to 6 or 7 

 millim., and the piece of bark placed between them, it assumed 

 a strongly diamagnetic position, and indeed was ejected from the 

 line of the ainces of the poles. When raised 4-5 millim., it again 

 became magnetic. 



13. In a hen's egg, magnetism only occurs in the white mem- 



• A general result, at which I arrived in the commencement of my experi- 

 mental investigations, hut which I can only allude to here, is, that the outermost 

 bark of all plants is magnetic. All those experiments which have been made 

 without a knowledge of the results detailed in the present memoir, although 

 the genera] conclusions are not deprived of their accuracy, must necessarily be 

 indefinite and inaccurate as regards the details, and require repetition \mder 

 the new point of view. 



