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Bafalt. 455 ori»in, for inany fiones are magnetic which no one pretends to be volcanic. For inftance, gar- nets hornblendes, the fhorls found near Gcne- va and the metalliferous l'tone of Born, i Bergm. -Jour. 1789, p. 607. There is another fyftem which attributes not only to bafalts, but to all ftony fubdances, an Dneous origin ; it is that of 1 .azaro Ivloro, re- ^ved, and wonderfully improved, by Dr. Hut ton, of Edinburgh, well known, by bis excellent EUay on the Örigin of Rain. This may bc called the Pitttonic fyftem. I have endeavonred to fhew its faliacy in a paper ‘lately read to the Royal Irifh Academy, which - will appear in. the next volume of its Tranfaftions. All that has oeen hitherro faid tends to dif- prove the igneous origin of baiahs, and confe* quently to evince its producfion in the mpift way, as there is no medium between the one and the other; I ihall now, however, ifate a few reafons that point diretfly to a Neptunian ori- ein. ift, It is well known, to thofe who occupy themfelves with mineralogical refearches, thw in ftanes compofed of three or four ingredients, tranfitions or gradations are irequently oblefved, from the more limple to the more compound, or vice verfa, or from one Ipecies of ftone to ano ther that bears it a kindred rclation ; fo that. it any of the terms of the tranfition be of volcanic origin, the wholc graduating ferics muH be of the fame origin ; and, if any of the terms be’ de- cidedly Neptunian, the whoie ieries muft be Neptunian. This ingenious and convincing mode of inveftigation was difcoveied, and, in this cale, happily applied, by Mr. Werner, on the G g 4 moun-