Linda Hall Library of Science, Engineering, & Technology
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53. Keir, Basalt, and Cooling Glass, 1776

Keir, James (1735-1820). "On the crystallizations observed on Glass". Philosophical Transactions of the Royal Society of London, 1776, 66:530-542

James Keir was not a geologist but a well-known chemist, who moved in an intellectual circle known as the Lunar Society that included James Watt and Matthew Boulton, of steam-engine fame, and Josiah Wedgwood, the maker of porcelain. In experiments with molten glass, Keir discovered that if glass were cooled very slowly, it did not assume a glassy structure, but instead became crystalline, very much like fine-grained basalt. In this paper of 1776, he suggested that perhaps he had discovered evidence that basalt was an igneous rock, and then made a remarkable intellectual leap, by suggesting that the basalt of the Giant’s Causeway was the product of a volcano.