rected to Geology, a science then in its infancy, he brought his knowledge of chemistry to bear upon the many difficult and interesting problems of Chemical Geology. In 1826 he published a paper " Sur l'origine des sources Minerales." In 1827 a paper " Sur les efflorescences des Roches Volcaniques." These were followed by various papers on Fossil bones, the inflammable gases of Coal- mines, Volcanic rocks, Glacier action, and others in the 'Neues Jahrbuch.' Many of his papers appeared in the ' Edinburgh New Philosophical Journal ; ' amongst them are to be found " On the Natural History of Volcanoes and Earthquakes," " On the Terrestrial arrangements connected with the appearance of Man on the Earth," " On the cause of the Temperature of Hot and Thermal Springs, and on the bearings of this subject as connected with the general question regarding the internal temperature of the Earth." He also treated of " The Glaciers in their relation to the elevation of the Alps," and of " The Formation of Quartz and Metallic Veins."
Most of his early papers were afterwards embodied in his great work the ' Lehrbuch der chemischen und physikalischen Geologie,' which appeared between 1847 and 1854. In the latter year a translation of this work by Dr. Paul and Dr. Drummond, made under the supervision of the author, was published by the Cavendish Society. This important work, more condensed than the German edition, is in some respects an independent work. In the first volume, the laws of combination of the mineral kingdom, pseudomorphic minerals, the action of water as a chemical and a transporting agent, the origin of springs, the action of rivers and of the sea, the mechanical and chemical deposits from water, and the character and origin of carbonaceous substances, of various gases, and of the simple salts occurring in the mineral kingdom, are treated of; while in the second the chemical reactions relating to the alteration of minerals, and the characters of and changes in Felspathic and various other minerals, especially those of volcanic and igneous origin, are considered. No geological studies can be complete without a knowledge, at all events, of the elements of Chemical Geology. In 1861, Professor Bischoff was elected a foreign Fellow of this Society ; and in 1863 the Wollaston Medal was awarded to him by the Council, in recognition of the eminent services rendered by him to Geological science by his long- continued and laborious chemical investigations on the origin and changes of minerals and rock- substances, and especially by the production of his great work on Physical and Chemical Geology.
