1911 Encyclopædia Britannica/Lasaulx, Arnold Constantin Peter Franz von

LASAULX, ARNOLD CONSTANTIN PETER FRANZ VON (1839–1886), German mineralogist and petrographer, was born at Castellaun near Coblenz on the 14th of June 1839. He was educated at Berlin, where he took his Ph. D. in 1868. In 1875 he became professor of mineralogy at Breslau, and in 1880 professor of mineralogy and geology at Bonn. He was distinguished for his researches on minerals and on crystallography, and he was one of the earlier workers on microscopic petrography. He described in 1878 the eruptive rocks of the district of Saar and Moselle. In 1880 he edited Der Aetna from the MSS. of Dr W. Sartorius von Waltershausen, the results of observations made between the years 1834–1869. He was author of Elemente der Petrographie (1875), Einführung in die Gesteinslehre (1885), and Précis de pétrographie (1887). He died at Bonn on the 25th of January 1886.