Dr.Paris has given an account of a modern formation of sandstone on the northern coast of Cornwall;** where a large surface is covered with a calcareous sand, that becomes agglutinated into a stone, which he considers as analogous to the rocks of Guadaloupe; and of which the specimens that I have seen, resemble those presented by Captain Beaufort to the Geological Society, from the shore at Rhodes.

Dr.Paris ascribes this concretion, not to the agency of the sea, nor to an excess of carbonic acid, but to the solution of carbonate of lime itself in water, and subsequent percolation through calcareous sand; the great hardness of the stone arising from the very sparing solubility of this carbonate, and the consequently very gradual formation of the deposit--Dr.MacCulloch describes calcareous concretions, found in banks of sand in Perthshire, which present a great variety of stalactitic forms, generally more or less complicated, and often exceedingly intricate and strange,*** and which appear to be analogous to those of King George's Sound and Sweer's Island: And he mentions, as not unfrequently occurring in sand, in different parts of England (the sand above the fossil bones of Norfolk is given as an example) long cylinders or tubes, composed of sand agglutinated by carbonate of lime, or calcareous stalactites entangling sand, which, like the concretions of Madeira, and those taken for corals at Bald-Head, have been ranked improperly, with organic remains.
(*Footnote.

Peron Voyage etc.

2 page 116.) (**Footnote.

Transactions of the Geological Society of Cornwall volume 1 page 1 etc.) (***Footnote.