HE eight bulletins referred to below cover a wide range of applied geology, and contain many valuable additions to academic geology. Thus the memoir by Messrs. Hillebrand and Schaller is a most important contribution to knowledge of the minerals containing mercury. It gives the result of a thorough research on kleinite, montroydite, terlinguaite, and eglestonite. The two last are proved to be oxychlorides, and montroydite to be an oxide of mercury, confirming the conclusions of Prof. Moses, the founder of these species. Kleinite was named in 1905 by Prof. Sachs, who described it as an oxychloride of mercury, but the day after his paper was read, in Berlin Hillebrand announced that the mineral is a mercury-ammonium compound; it is a mixture of mercury ammonium chloride with some sulphate or oxysulphate. Some interesting photographs illustrate the optical heterogeneity of the mineral. Kleinite is hexagonal in symmetry, but basal sections are only singly refracting when heated above 130°; after cooling very slowly, in process of years, again become biaxial.