On the action of carbonic acid water on minerals and rocks

Abstract

Having for the last two years been engaged more or less continuously in investigating the nature of chemical disintegration of mineral and rocky substances, I propose to submit to the Society some account of the simple experiments which, up to the present time, I have been enabled to carry through. The minerals which I subjected to experimental examination, were those that enter most largely into the composition of the principal rocks of the earth’s crust, and the rocks studied were those which occur most abundantly in the British Isles. On these mineral and rock substances I allowed water, saturated with carbonic acid gas, to act for a certain time. The amount of carbonic acid water taken for all my experiments was one litre, and the temperature of the water was always kept at nearly 4° C. At present I can only give you the results of my experiments on Orthoclase, Oligoclase, Labradorite, Muscovite, Biotite, Hornblende, Augite, Magnetite, Haematite, Calcite, and Crystalline Limestone. Three pieces of Orthoclase felspar, which I will call A, B, and C respectively, after having been carefully weighed, were placed in separate portions of distilled water saturated with carbonic acid gas, and allowed to remain for three months. A, with its carbonic acid water, was placed in a flask which was corked and put away on a shelf, and was never touched or moved in any way for three months, so that the water in which this specimen was suspended and completely immersed was always during that