NOMOS. 85 



prevents these recombinations. Under these circum- 

 stances there is not a current in the steel ; but there 

 is, as it were, a current dammed up, a current 

 "frozen into permanence." Again, the common 

 oxides of iron, and other oxides, are not electrical 

 "conductors" for the same reason that steel is a 

 worse conductor than iron. The affinities of the 

 iron elements are preoccupied by the oxygen ; and 

 the elements cannot yield themselves readily to the 

 play of those chemical decompositions and recombi- 

 nations which constitute the current. But if it 

 happens that these molecules are decomposed after 

 the fashion which obtains in the current, and the 

 separated elements combined with oxygen, the 

 separated elements are still able to react in some 

 degree even after this combination ; and the oxygen 

 serves to perpetuate this condition by presenting a 

 mechanical barrier to the reunion which would put 

 an end to the reaction. And so also with the 

 magnetic sulphuret of iron; for in this ease the 

 sulphur plays the part of the oxygen in the magnetic 

 oxide, of the carbon in the magnetic needle, and of 

 the glass in the Leyden jar. Upon this theory, 

 indeed, all that is necessary to fix the phenomena 

 of magnetism is to have some mechanical medium 

 interposed between the polar elements of the mole- 

 cules, a medium sufficient to prevent the reunion 

 of these elements, but not sufficient to prevent their 

 mutual reaction. It is still the chemical hypothesis 

 to which we have recourse for the explanation ; and 

 thus the loadstone becomes the real key to the 

 mystery of electrical action. It is this stone which 



G 3 



