chemical Agencies of Electricity. 55 
concerned, produced in various parts of the interior strata of 
our globe. 
Where pyritous strata and strata of coal-blende occur, 
where the pure metals or the sulphurets are found in contact 
with each other, or any conducting substances, and where 
different strata contain different saline menstrua, electricity 
must be continually manifested ; and it is very probable, that 
many mineral formations have been materially influenced, or 
even occasioned by its agencies. 
In an experiment that I made of electrifying a mixed solu- 
tion of muriates of iron, of copper, of tin, and of cobalt, in a 
positive vessel, distilled water being in a negative vessel, all 
the four oxides passed along the asbestus, and into the ne- 
gative tube, and a yellow metallic crust formed on the wire, 
and the oxides arranged themselves in a mixed state round 
the base of it. 
In another experiment, in which carbonate of copper was 
diffused through water in a state of minute division, and a 
negative wire placed in a small perforated cube of zeolite in the 
water, green crystals collected round the cube ; the particles 
not being capable of penetrating it. 
By a multiplication of such instances the electrical power 
of transference may be easily conceived to apply to the ex- 
planation of some of the principal and most mysterious facts 
in geology. 
And by imagining a scale of feeble powers, it would be 
easy to account for the association of the insoluble metallic 
and earthy compounds, containing acids. 
Natural electricity has hitherto been little investigated. 
