Page:Memoirs of the Geological Survey of Great Britain, Volume 1.djvu/457

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444
INFLUENCE OF MAGNETISM ON CRYSTALLIZATION

444 INFLUENCE OF MAGNETISM ON CRT8TA1LIZATI0N

an arrangement precisely nnular to that shown by the oxide, bat the curres formed were more permanent in their character.

22. Oxide of gold shows a similar diamagnetic arrangement, but there appears to be less tendency even to any regularity of form, than with the tin. In many respects the oxide of gold and that of tin, under the influence of the magnet, strikingly resemble each other ; and, from numerous experiments made with both, I am inclined, at present, to re* gard their diamagnetic conditions as yery similar.

23. Gold, precipitated by the protosulphate of iron from the neutral chloride, has invariably fallen without any appearance of dther attrac- tion or repulsion, excepting strong solutions of iron were used, when it was attracted by the magnetic poles ; but this was evidently owing to the presence of a truly magnetic salt.

24. Chloride of platinum and nitrate of potash^ forming a double salt^ exhibits some obedience to magnetism whilst in motion, but under no other circimistances. It then forms some curves of rotation, but these accumulating on each other are speedily obliterated.

25. The oxide of platinum^ precipitated by an alkaline salt, invari* ably gives curves of repulsion during the time the mixing of the two solutions is going on ; but when this disturbance is over there is a gradual accumulation of the precipitate about the magnetic poles. I am inclined to regard the diamagnetic curves, first formed, as depending on the potash or soda employed, particularly since Dr. Faraday has, by his experiments, placed platina amongst magnetic bodies, and sodium with those of a diamagnetic character.* This metal, like gold and tin, does not appear to exhibit any very decided property. Further experiments^ with a view of determining their conditions still more accurately are» however, contemplated.

  • The following liit his been giyen by Froienor Furaday :—

JTo^Mfic. Diamagmdie.

Biimuth.

Antimonj.

Zinc.

Tin. Iron, Cadmium.

NickeL Sodium*

Cobalt Mercury.

Manganeee. Lead.

Chromium. Silyer.

Cerium. Copper*

Titanium. Gold.

Palladiunu Anenie. '

PlaHnmiu Uranium.

Oamtum. Rhodium.

Tridiom.

Tungsten.

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