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veries have been made of late years, articularly in the South Seas, of islands which owe their birth to volcanic explosions; and some, indeed, where the volcanic fire still operates. I am led to believe, that upon further examination, most of the elevated islands at a considerable distance from continents would be found to have a volcanic origin; as the low and flat islands appear in general to have been formed of the spoils of sea productions, such as corals, madrepores, &c. But I will stop here, and not deviate from the plan which I have hitherto strictly followed, of reporting faithfully to my learned brethren of the Royal Society such facts only as come immediately under my own observation, and as I think may be worthy of their notice, and leave them at full liberty to reason upon them. “We may flatter ourselves, as a very great progress has been made of late years in the knowledge of volcanoes, that by combining such observations as we are already in offession of, with those which may {. made hereafter, in the four quarters of the world (in all of which 'nāture seems to have operated in a like manner), a much better theory of the earth may be established than the miscrable ones that have hitherto appeared. “Those who have not had an opportunity of examining a volcanic country, as I have for more than twenty years, would little suspećt, that many curious productions and combinations of lava's and tuffa’s were of a volcanic origin; efpecially when they have undergone various chemical operations of nature, some of which, as I have mentioned in a former communication as well as in this, have been capa

ble of converting tuffa's, lava's, and pumice stone, into the purest clay.

“I have remarked, that young observers in this branch of natural history are but too apt to fall into the dangerous error of limiting the order of nature to their confined ideas: for example, should they suspect a mountain to have been a volcano, they immediately climb to its summit to seek for the crater, and if they neither find one, or any signs of lava or pumice stone, direétly conclude such a mountain not to be volcánic: whereas, only suppose Mount Etna to have ceased erupting for many ages, and that half of its conical part should have mouldered away by time (which would naturally be the consequeuce) and the harder parts remain in points, forming an immense circuit of mountains (Etna extending at its basis more than one hundred and fifty miles); such an observer as I have just mentioned would certainly not find a crater on the top of any of these mountains, and his ideas would be too limited to conceive, that this whole range of mountains were only part of what once constituted a complete cone and crater of a volcano. It cannot be too strongly recommended to observers in this, as well as in every other branch of natural his. tory, not to be over hasty in their decisions, nor to attribute every production they meet with to a single operation of nature, when perhaps it has undergone various, of which I have given examples in the island which has been the principal subject of this letter. That which was one day in a calcareous state and formed by an insect in the sea, becomes vitrified in another, by the aćtion of the volcanic fire, and the addition of some natural ingredi

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ACCOUNT of a New ELECTRICAL FISH, in a Letter from Lieutenant WILLIAM PATER son, to Sir Joseph BANks, Bart. P. R. S.

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