Salts of the Magnetic Metals, 



369 



the product of the specific magnetism into the atomic weight is con- 

 stant, or the magnetism of each atom of these compounds is the 

 same. In this respect the oxygen salts and haloid salts cor- 

 responding to one another show the same deportment. 



The mean magnetic moments of an atom of a protosalt of 

 nickel, cobalt, iron, and manganese are as 142 : 313 : 387 : 468. 



5. Hence the magnetism of an atom of the cobalt salt is very 

 nearly the mean between the magnetisms of the atoms of salts of 

 nickel and manganese, J (142 + 468) =305. In like manner the 

 magnetism of the atom of ferrous salts is the mean between the 

 magnetisms of the atoms of cobalt and manganese salts, 

 i(313 + 468) = 390-5. 



The atoms of salts of different oxides of the same metal have, 

 on the other hand, very different magnetism — thus, for instance, 

 the atoms of ferrous and ferric salts, whose magnetisms with 

 the same weight. of iron are as 1 : 1*24. Ferric oxide obtained 

 in the soluble form by dialysis, as well as basic compounds of 

 ferric oxide with acids in which a part of it is in the same con- 

 dition, behave like the soluble ferric oxide. 



Finally a number of solid salts were investigated. The mag- 

 netic momenta m of the same weights, as well as the products p, 

 of the values m into the atomic weights, were 





Wl*. 



fX. 



Ferrous sulphate (crystallized) 



Ferrous chloride (anhydrous) 



Ammouio-ferrous sulphate (crystallized) 

 Sulphate of manganese (crystallized). . 



Sulphate of cobalt (crystallized) 



Sulphate of cobalt, I. (anhydrous) .... 

 Sulphate of cobalt, II. (anhydrous) . . 

 Ferric chloride 



46-87 

 57*71 

 20-81 

 60-92 

 38-09 

 38-13 

 39-19 

 55-41 



3183 

 3660 

 4078 

 4600 

 2950 

 2954 

 3038 

 9000 





6. Hence the magnetism of the dry salts is almost the same 

 as the magnetism of the same salts when dissolved ; the combina- 

 tion of anhydrous salts with water of crystallization does not ma- 

 terially alter their magnetism. 



7. From a few further experiments the insoluble salts show the 

 same deportment (phosphate and carbonate of cobalt, manganous 

 phosphate); so that in these salts also the product of the specific 

 magnetism into the atomic weight has the same value as in the 

 soluble salts. 



* Except in the case of ammonio-ferrous sulphate, the values m refer to 

 the proportion of anhydrous salt. 



Phil. Mag. S. 4. Vol. 30. No. 204. Nov. 1865. 2 B 



