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JOURNAL 



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NATURAL PHILOSOPHY, CHEMISTRY^ 



THE ARTS. 



OCTOBER 1798. 



ARTICLE I. 



Curious Ctrcumjfauces upon ivh'tch the Vitreous or the Stony CharaEfer of Whinjlone ancl Lavx 

 refpeElively depend ; with other FaHs. In an Account of Experiments made by Sir J AMES 

 Hall, Bart. F.R. and A.S.S. Edin* 



G, 



'N the 5th March, and i8th of June, Sir James Hall read to the Royal Society of 

 Edinburgh an account of a feries of experiments on whinftone and lava. Thefe experi- 

 ments, which relate to the theory of the earth publiflied by the late Dr. Hutton, had bcea 

 projefted by Sir James Hall in 1 790 ; at which time he read a paper to the fociety on the 

 formation cf granite and other unftratified-fubftances. He had then begun a few experi- 

 ments, but ha.l been obliged by fome circumftances to difcontinue them. Having obtained^ 

 however, very promifing appearances of fuccefs, they were again refumed, and carried into- 

 elFedt in the courfe of laft winter \, In the execution of the experimental part, Sir James 

 Hall acknowledges himfelf greatly indebted to the affiflance of Dr. Kennedy. 



The fubjeiSl of the communication was fuggefted by fome obvious and plaufible objec- 

 tions which have lately been urged againft Dr. Hutton's fyftem. Whinftone or bafaltes 

 being confidered in that fyftem as having attained its prcfent pofition in a ftate of igneous 

 fufion, it has been alledged, as a fufhcient refutation of this hypothefis, that whinftone, 

 when made to undergo fufion in one of our furnaces, yields glafs, a fubftance very different 

 from the original ftone } the formation of which cannot therefore be afcribed to the a£lioa 

 of fire. 



* Abftraft, by favour of the Author, from his Paper which will appear in the Edin. Tranf. vol. v. 

 + Sir James Hall fiiowed the refult of his firft fuccefsful experiment at a meeting of the Society on the 5th: 

 •f February, 179?. 



Vol. IL— Oct. 1798^. Eg . This 



