HAIDINGER, Wilhelm von (1795-1871), a mineralogist, geologist, and physicist of considerable note, was born at Vienna, February 5, 1795. His father, Karl Haidinger, contributed largely to the development of mineralogical science in the latter half of the last century. Having studied at the normal school of St Anne, and attended classes at the university, Wilhelm, at the age of seventeen, joined Professor Mohs at Gratz, and five years later accompanied the professor to Freiberg on the transfer of his labours to the mining academy of that Saxon ElDorado. In 1822 Haidinger visited France and England with Count Breunner, and, journeying northward, took up his abode in Edinburgh. He translated into English, with additions of his own. Mohs’s Grundriss der Mineralogie, published at Edinburgh in three volumes under the title Treatise cη Mineralogy, 1825. After a tour in northern Europe, including the Scandinavian mining districts, he undertook the scientific direction of the porcelain works at Elnbogen, belonging to his brothers. In 1840 he was appointed counsellor of mines (Bergrath) at Vienna in the place of Professor Mohs, a post which included the charge of the imperial cabinet of minerals, &c. He devoted himself to the rearrangement and enrichment of the collections, and the cabinet became the first in Europe. Shortly after (1843) Haidinger commenced a series of lectures on mineralogy, which was given to the world under the title Handbuch der bestimmenden Mineralogie (Vienna, 1845; tables, 184G). On the establishment of the imperial geological institution, he was chosen director (1849); and this important position he occupied for seventeen years. On the completion of the geological survey of the Austrian dominions in 1862, he superintended the preparation of the maps ...