MAGNECRYSTALLIC CONDITION OF ANTIMONY — OF ARSENIC. 
17 
(2315.). But if the magnetic force be continued, it will then be perceived that the 
stop is only apparent ; for the plate moves, though with a greatly reduced velocity, 
and continues to move until it has taken up its magnecrystallic position. It moves as 
if in a thick fluid. Hence the magnecrystallic force is there and produces its full effect; 
and the reason why the appearances have changed is, that the very motion which the 
force tends to give, and does give to the mass, causes those magneto-electric cur- 
rents (2329.) which by their mutual action with the magnet tends to stop the motion ; 
and therefore its slowness and the final dead set (2512. 2523.). 
2528. A magnet which is weaker (as the horse-shoe instrument described (2485.)) 
produces the currents by induction in a much weaker degree, and yet manifests the 
magnecrystallic power well ; hence it is more favourable, under certain circum- 
stances, for such investigations ; as it helps to distinguish the one effect from the 
other. 
2529. It will readily be seen that plates, whether of the same metal or of different 
metals, cannot, even roughly, be compared with each other as to magnecrystallic 
force by their vibrations ; for under the influence of these induced currents, plates 
of the same magnecrystallic force oscillate in very different manners. I took a plate, 
and by cement (2458.) attached selected paper to its faces, and then observed how 
it acted in the magnetic field ; it set slowly, and it showed the arresting and revulsive 
effects (2521.). I then pressed it in a mortar, so as to break it up into many parts, 
which still kept their place ; and now it set more freely and quickly, and showed 
very little of the revulsing action. 
2530. Though the indication by vibration is thus uncertain, the torsion force still 
remains to us, I believe, a very accurate indication of the strength of the set (2500.) ; 
and, therefore, of the degree of the magnecrystallic force ; and though the suspending 
silk fibre may give way a little, a glass thread, according to Ritchie’s suggestion, 
would answer perfectly. 
2531. Antimony must be a good conductor of electricity in the direction of the 
plates of the crystals, or it would not give, so freely, these indications of revulsive 
action. The groups of crystals of antimony (2508.) showed the effect in such a de- 
gree, as to make me think that the constituent cubes possessed the power nearly 
equally in all directions. A piece of finely crystallized or granular antimony does 
not, however, show it in the same proportion ; from which it would seem as if an 
effect equivalent in some degree to that of division occurs, either at the meeting of 
two incongruous crystals, or between the contiguous plates of the crystals, and affects 
the conducting power in these directions. 
^ iii. Crystalline Polarity of Arsenic. 
2532. A mass of the metal arsenic exhibiting crystalline structure (2480.), was 
broken up, and several plates selected from the fragments, having good cleavage 
plane surfaces, about 0 3 of an inch in length, 0*1 inch in width, and 0‘03 in thick- 
MDCCCXLIX. D 
