To remove that obstacle in the way of the aqueous theory, or to carry that theory over the obstacle which he cannot remove, our author undertakes to refute my theory with regard to the igneous origin of stony substances, by giving an example of granite formed upon the surface of the earth by means of water, or in what is called the moist way; and he closes his Dissertation with this example as an experimentum crucis.  It is therefore necessary that I take this demonstration of our author into particular consideration; for, surely, independent of our controversy, which is perhaps of little moment, here is the most interesting experiment, as it is announced, that mineralogy could be enriched with.

“To close this controversy,” says our author, “I shall only add, that granite, recently formed in the moist way, has been frequently found.”—­Of that remarkable event, however, he has selected only one example.  This is to be found upon the Oder; and the authority upon which our author has given it, is that of Lasius Hartz.

The formation of a granite stone, from granite sand, by means of water, is inconsistent with our chemical knowledge of those mineral substances which constitute that stone; it is repugnant to the phenomena which appear from the inspection of the natural bodies of this kind; and it is directly contrary to the universal experience in granite countries, where, instead of any thing concreting, every thing is going into decay, from the loose stones and sand of granite, to the solid rock and mountains which are always in a state of degradation.  Therefore, to have any credit given to such a story, would require the most scientific evidence in its favour.  Now, in order that others may judge whether this has been the case in this example, I will transcribe what our author has said upon the subject; and then I will give the view in which it appears to me.

He says, “a mole having been constructed in the Oder in the year 1723, 350 feet long, 54 feet in height, 144 feet broad at bottom, and 54 at the top, its sides only were granite, without any other cement than moss; the middle space was entirely filled with granite sand.  In a short time this concreted into a substance so compact as to be impenetrable by water.”—­Here is an example, according to our author, of granite formed in the moist way.  But now, I must ask to see the evidence of that fact; for, from what our author has told us, I do not even see reason to conclude that there was the least concretion, or any stone formed at all.  A body of sand will be so compacted as to be impenetrable by water, with the introduction of a very little mud, and without any degree of concretion; muddy water, indeed, cannot be made to pass through such a body without compacting it so; and this every body finds, to their cost, who have attempted to make a filter of that kind.