Hasbrouck, Louis, 1777-1834.

An intellectual prodigy in his native Glasgow, the chemist John Maclean (1771-1814) was only 13 when he entered the University of Glasgow and by the time he was 20, he had studied at Edinburgh, London, and Paris, and, for the sake of employment, had received a medical degree from Glasgow. He was appointed to the faculty of Physicians and Surgeons at Glasgow in the following year, but while practicing medicine, he continued to read in chemistry and to conduct experiments whenever possible.

Maclean's burgeoning interest in chemistry was kindled during one of the most vibrant periods in the history of the discipline, the peak of the chemical revolution. At Edinburgh, he had studied with the meticulous empirical chemist Joseph Black, and while in Paris, he was exposed to the groundbreaking theories of Antoine Laurent Lavoisier, quickly adopting that system and nomenclature, as well as Lavoisier's characteristic quantitative bent and disdain for phlogistic theory. At about the same time, Maclean is also said to have become a wholehearted republican, and whether from political or professional motives -- or both -- he left Scotland for the United States in April 1795.

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