The following observations are based chiefly upon the results of an exhaustive survey of the specimens in the Scottish Mineral Collection in the Edinburgh Museum of Science and Art, which were made while I was studying the material for completing The Mineralogy of Scotland. The survey has been continued since the publication of that work, in connection with the revision of the arrangement of the specimens in question. A large number of facts of interest have come to light in the course of this work. Furthermore, the forms of several hundreds of crystals in the Collection have now been determined, and freehand drawings of most of these crystals have been made, and placed alongside of the specimens to which they refer. It is proposed from time to time to lay some of the more interesting of the results arising from this work before this Society, especially as little or none of them have hitherto been published, and as the crystals, which present considerable interest, do not appear to have been previously figured.