288 ON THE PARTICULAR ORDER OF Micaceous Schist Chlorite Schist Limestone Argillaceous Schist Gneiss. In this particular case, the alternations amount to some thousands. To proceed now to the secondary strata, it will he best to give the order of succession in England, and in an entire state, as it is conceived to be determined by the numerous geologists who have bestowed great labour and care on this department. The groupings of the beds, or the divisions into series, must stand on the authority or opinions of observers whose ability and industry arc admitted, and who are too well known to need mention here. On the Succession of Strata in England and Scotland. The lowest bed of the secondary strata of England, is the old red sandstone, being the first of the secon dary rocks in the artificial classification It must not however be considered as a simple rock ; since, be sides the conglomerate which is essential to it, it sometimes contains shales and limestone, and, occa sionally, coal. The next bed in the order upwards, is a limestone containing a few fossil remains, and known by the name of mountain and of carboniferous limestones. In this rock also, there are found smaller beds of shale, and, occasionally, of sandstone; much more rarely, of coal. A sandstone called the Millstone grit follows in some places ; but it seems to be one of the most limited of these, leading strata, while it does not appear very satisfactorily proved that it does not form a part of the coal series.