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LXXI. On the relation of Magnetism and Diamagnetism to the 

 Colour of Bodies. By Richard Adie, Esq., Liverpool*^. 



WHILE occupied with some experiments in the latter part 

 of the year 1850, to test the magnetic pi-operties of a 

 variety of bodies, I was struck with the preponderance of trans- 

 parent or white bodies among the class of diamagnetics ; I con- 

 sequently followed this branch of the inquiry, and in the follow- 

 ing year gave, in Jameson's Edinburgh Journal, a table to 

 prove that the diamagnetic metals produced a much larger 

 proportion of colourless compounds than the magnetic ones. In 

 the present instance I propose to return to the subject, to show 

 that when the inquiry is confined to the oxides and chlorides, a 

 similar relation subsists, although among the elementaiy bodies 

 themselves there appears to be no connexion of the sort ; indeed 

 they tend to range themselves in an order opposite to that of the 

 table I have alluded to, oxygen being magnetic and colourless, 

 while chlorine, iodine, and bromine are diamagnetic and highly 

 coloured. 



It is in their compounds that the tendency of transparent sub- 

 stances to diamagnetism is seen, and in none is this more satis- 

 factorily shown than in the most important of all the diamag- 

 netics, water, for there 8 grs. of oxygen, a decidedly magnetic 

 body, enter into combination with 1 gr. of hydi'ogen, a body of 

 feeble diamagnetic properties, and produce 9 grs. of water, which 

 the magnet repels, so that the magnetism of 8 parts of oxygen 

 are more than counterbalanced by the diamagnetism of 1 part of 

 hydrogen after their chemical union. Further, oxygen, where it 

 forms colourless oxides with metals of very feeble magnetic pro- 

 perties, produces compounds where the magnetic power of the 

 oxygen is masked, and there results a diamagnetic body like 

 water ; of these, Iceland spar, quartz and potash furnish instances. 



In these cases, oxygen, although magnetic in itself, acts as a 

 destroyer of magnetism in the new compounds ; and if we turn 

 to the oxides of the strongly magnetic metals, this property of 

 oxygen is seen in a manner even more marked. For example, in 

 the red oxide of iron a great amount of magnetic force is masked 

 by the union of the oxygen with the iron. 



The metals of marked magnetic or diamagnetic properties form 

 but a small proportion in the general list of metallic bodies ; 

 three only can be said to be decidedly magnetic, namely, iron, 

 nickel and cobalt; and four diamagnetic, bismuth, antimony, 

 zinc and tellurium. Diamagnetism never assumes the power of 

 magnetism ; but in the four metals named, the property is suffi- 

 ciently marked to manifest itself in the presence of minute im- 



• Communicated by the Author. 



2 fi 2" 



