But the most puzzling thing about the place is, that out of the mud comes upnot jumbies, but a multitude of small stones, like no stones in the neighbourhood; we found concretions of iron sand, and scales which seemed to have peeled off them; and pebbles, quartzose, or jasper, or like in appearance to flint; but all evidently long rolled on a sea-beach.

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 depositDr.

Rottnest Island and its vicinity, latitude 32 degrees, contains in abundance the calcareous concretions already mentioned; which seem there to consist in a great measure of the remains of recent shells, in considerable variety.

The vines on the Summit were now in full leaf, and they covered broad patches of the rock with their luxuriant vegetation, while the grass could actually be seen from the ship, converting the drab-coloured concretions of the mount into slopes and acclivities of verdure.

These specimens, however, do not really exhibit any traces of organic structure; and so nearly resemble the irregular stalactitical concretions produced by the passage of calcareous or ferruginous solutions through sand* that they are probably of the same origin; indeed the central cavity of the stalactite still remains open in some of the specimens of this kind from Sweer's Island in the Gulf of Carpentaria.

As for me, I can wear only concretions and growths; emeralds and all their cousins would be shockingly inharmonious on me; but you know, Lu, how I use Indian spices, and scarlet and white berries and flowers, and little hearts and notions of beautiful copal that Rose carved for you,and I can wear sandal-wood and ebony and pearls, and now this amber.