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material at different times. It is indeed a most ingenious hypothesis, and 
appears to agree with facts ; hut then the pre-existing theory is more natural, 
and is at least compatible with what we see occurring every day, which Mr. 
Kelly’s view is not. The author thus puts forward his opinions : “ Grains of 
sand and particles of mud, derived from other rocks decomposed by sun, 
frost, and rain, and brought down as sediment in rivers, would form new beds 
or masses homogeneous in lithological character, and would not have the 
coarse grains sorted for one bed, and the fine mud for another. This alterna- 
tion of hard and soft beds occurs in the older sedimentary rocks, in common 
with the recent trap rocks of Garrow Point. Both are apparently produced 
by subterranean agency, acting on materials of different natures, the basaltic 
layer thrown up in a melted state ; the sandstone beds, the materials of which 
were not so easily fusible, thrown up in the state of sand or mud, and all 
spread out on the bottom of the ocean in beds or layers, as already described.” 
Mr. Kelly must excuse our telling him that he begs the entire question. He 
assumes that the matter borne down from the surface of land by rivers, is 
deposited in one homogeneous mass ; but every-day experience opposes this. 
Let the writer make a section even of a seashore gravel-bed of ordinary size, 
and he will find the fine silt in separate layers from the pebbles. When 
mineral matter is borne down to the ocean by the rapid current of a river, 
it is in great part held in suspension by the velocity of the current ; when, 
however, it reaches the sea, the stream ceases, and the suspended matter falls 
to the bottom ; the larger or heavier particles will sink soouest, and the finer 
mud will be the last to subside. Then again, after several strata have in 
this way been formed, the silt-like material must gradually be pressed into 
separate layers. It appears to us that Mr. Kelly’s process of reasoning is by 
no means unlike the method by which he assumes mud to be deposited under 
ordinary circumstances. The heavier and more substantial arguments become 
mingled in the most heterogeneous and confused manner, with the lighter and 
more trivial ones, and those who would^ analyze the mental deposits which 
this gentleman’s work exhibits, find no small trouble in estimating the means 
by which they have been formed. Who, for example, could form a clear 
notion of what the writer intended to convey in the annexed passage ; — “ If the 
grains of sand be imagined to have been brought from the external surface of 
the earth, and used to make up beds of rock, instead of having been obtained 
from the interior nucleus, in considering geological phenomena, as deduced 
from those different ways of obtaining the materials of beds, the train of 
reasoning is different, the conclusions drawn are different, and error probably 
put in place of truth, both in theory and practice.” There is only one part of 
the treatise under notice which contains a display of j ustifiable scepticism. 
When Mr. Kelly contends that much of what is called “ Old Bed Sandstone ” 
in Ireland is really carboniferous, we are disposed to agree with him. All 
the evidence, both geological and palaeontological, supports his view of the 
matter. The Tower of Hook Promontory, in the co. Wexford, affords a beau- 
tiful natural section of the two systems, and shows that the carboniferous 
lies conformably in the Devonian, and passes so gradually into it that it is 
quite impossible to point out the beginning of one or the termination of the 
other. Besides the absence of the fish characteristic of the Old Eed Sandstone, 
and the presence of thin seams of coal and several coal plants in the Irish 
