Time passes away, and we all of us grow older and older. As day by day the daylight lengthens or contracts, the air gets warmer or chillier, the skies brighter or bleaker, and everything around us imperceptably changes, it is only after the lapse of weeks that we perceive the change.

Yet Time never stays his rapid course; and in mid-life it is perhaps for the first time we stop in our onward path to feel, for the first time too, we are not what we were.

Years ago, when a child, I picked up shells and pebbles on the Kentish strands. In school-boy days, with bolder hand and surer foot, oft have I scrambled o'er those white chalk-cliffs, or clambered homewards for six long miles o'er sea-weeded rocks with satchel loaded full of fossils gathered from the slippery shores of Eastwear Bay, were the dark-blue crumbling Gault daily yields its crop of glittering fossils to the destructive battering of the salt sea waves.

Coral-Hunting in the debris of a Wenlock-shale quarry ranks high— to my thinking—amongst the pleasures of geology. And, indeed, has no insignificant place among its wonders. For to any one not conversant with zoophytic life, it is hard to believe that the rugged corals that lie strewn about the quarry, once held sensitive masses of life—that from every pore tiny arms waved to and fro in the water to entangle the lesser creatures they lived on; and that the animal— that slight thread of jelly-like substance, filling each tube, was at once a limb of the body and an independent creature, contributing, while attached, to the general support, and being able, if severed from the mass, to lead a separate existence and be itself the parent of others. The Wenlock series of the Upper Silurians have been rightly regarded as the metropolis of its zoophytic life, for both in variety and number, corals culminated in the seas of that age. Of these species, “so far removed from existing ones as to be quite unknown in modern seas, all with rare exceptions, dying out at the close of the Palæozoic epoch.” I will essay a familiar sketch.

The October number of the “Philosophical Magazine” contains a notice, translated from Poggendorff's “Annalen,” by Professor Gustav Rose, on the isomorphism of stannic, silicic, and zirconic acids. Stannic acid (n) forms the mineral Cassiterite, silicic acid (i) is Quartz, zirconic acid, which Rose considers to be r, has hitherto been classed as an earth or oxide, as zirconia, with composition r, or r. The mineral zircon, hitherto held to be a silicate of zirconia, must now, according to this, be merely considered as an isomorphous compound of one atom of zirconic acid and one atom of silicic acid (r + i). This mineral species has always been remarkable for the variation of hardness and gravity in specimens from different localities, which according to this hypothesis may be accounted for by the unequal proportions of the two acids; the heavier and harder specimens containing the more zirconic acid, whose equivalent would be 481·20 compared with 384·888 that of silica. In the case of a variety found in Russia by Hermann, composed of two atoms of r, with three atoms of i (r2i3), the specific gravity was only 4·06, while that of the mineral of the ordinary composition varies from 4·5 to 4·8.