Inventor of illuminating gas; b. at Maastricht, Holland, 1748; d. there 4 July, 1824. At the age of sixteen, in 1764, he went to Louvain, where he studied theology and philosophy at the Collège du Faucon, in which he became professor of natural philosophy in 1772. At this time the question of aerostats and Montgolfiers was occupying the mind of scientists, and the Duc d'Arenberg, a Mæcenas of science and art, engaged a committee to examine into the question of the best gas for balloon purposes. Minkelers was on this committee, and published in 1784, after many experiments, a work entitled "Mémoire sur l'air inflammable tiré de différentes substances, rédigé par M. Minkelers, professeur de philosophie au collège du Faucon, université de Louvain" (Louvain, 1784). As an appendix to this memoir there was a "Table de gravités spécifiques des différentes espèces d'air", by T.F. Thysbaert, a member of the committee. In his memoir Minkelers tells us how he made his precious discovery: from the very beginning of his experiments he had had the idea of enclosing oil in the barrel of a gun and heating it in a forge. Under action of the heat the oil dissolved and gave place to a remarkably light gas, having other advantageous qualities. Having proved that oil gas was the best for balloons, Minkelers used it for many balloons which rose rapidly and travelled great distances in the neighbourhood of Louvain. As we learn from his pupil von Hulstein, who was in his class in 1785, Minkelers at times used this same gas to light his workshop. Moreover, the drift of his memoir proves clearly that in its inventor's eyes the great combustibility of the gas was one of its leading qualities. When Joseph II, in 1788, transferred the University of Louvain to Brussels, Minkelers continued as professor, but when it was removed back to Louvain he refused to return. He resigned in 1794 and was appointed professor of physics and chemistry at the Central School of Maastricht, 4 July, 1824.
MINKELERS, Mémoire sur l'air inflammable tiré de différentes substances (Louvain, 1784); DE RAS, Historisch Verslag over J. P. Minkelers (Maastricht, 1897); VERHAEGEN, Les cinquante dernières années de l'université de Louvain (Liège, 1894); DE BOCKE, De vervaardiging van lichtgas uit steenkolen (Alkmaar, 1882).
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