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chemical affinity, so far as that is found in igneous or aqueous 
agencies. It is more powerful than pressure, or heat 
under pressure, or hydraulic force, ^ or anything else yet 
known in material changes. Yet this most inscrutable ot 
all forces seems scarcely thought of in relation to the trans- 
formation of rocks. Must not speculations on the effects of 
force, which leave out of calculatiou the most powerful force 
of all that is known in physics, be radically defective and 
misleading? Is it not this neglect which leads geologists so 
often into the gross error of imagining that even stagnation 
itself will issue in the most magnificent changes, if it is only 
allowed sufficient time ? n 
But the same defect is visible in the utterly inadequate 
accounts given of the positions of strata, the only upheaving 
force thought of is heat, and the only degrading force is water. 
In upheaval, water in the form of steam is thought of so far, 
but that only as it is, like the rocks themselves, affected by 
heat. Hydraulic force seems scarcely thought of, nor is that 
force fully considered, whatever it is, which makes water the 
parent of fire. Take a ship-load of burnt limestone, and let 
into the hold only a small portion of water, the result 
is fire, and a resistless rending and destruction of the 
vessel. So far as volcanic fires are concerned, there seems 
enough in this “ chemical affinity,” as it is called, to account 
for them, were it not for the associated earthquake. The 
shock of that seems to us to travel much too far to be 
accounted for by anything but electricity. The force which 
shakes the solid crust of the -globe throughout an area of two 
hundred miles in breadth, and as much as fifteen hundred 
miles in length, cannot, I humbly think, be referred on any 
reasonable principle, either to the agency of fire or to that ot 
chemical change. Ho development of force has any likeness 
to that required for such an effect, but such as we see m 
electricity. That strata should be rent and changed m 
mineral constitution, by a force that can affect the globe m 
this way, seems at least like reason, and it does not call for 
the time so anxiously prayed for by the fashion of the present 
geological day. 
But there is a more important defect to notice in relation 
to the positions of strata. We naturally inquire where the 
subsiding masses that are said to sink down into or through 
the earth’s “ crust ” are “ stowed away.” And how are the 
spaces out of which Alps and Andes, and even continents rise, 
so filled up as to suppoit such burdens? The conglomerate 
which lies below the Laurentian limestone contains, as we 
