One object of the Laboratory of the Industrial Museum is the prosecution of investigations likely to throw light on the economic value of materials employed in the useful arts. It has been impossible this winter to do more than make a small beginning by instituting an examination into the properties of certain of our building stones; and as the results obtained in the case of the sandstone of Craigleith Quarry have an interest for geologists as well as for architects and builders, they are laid before the Society, as all similar results of any scientific value will be in future.