Mr. James Jennings has favoured us with a copy of his _Ornithologia; or the Birds_, a poem; with copious _Notes;_ &c. The latter portion is to us the most interesting, especially as it contains an immense body of valuable research into the history and economy of birds, in a pleasant, piquant, anecdotical style, without any of the quaintness or crabbedness of scientific technicality. Mr. Jennings's volume is therefore well adapted for presentation to young persons; whilst the knowledge which it displays, entitles it to a much higher stand than a mere book of amusement. To illustrate what we have said in its praise, the reader will find in the _Supplement_ to the present Number, two or three of the most attractive _Notes_ under "THE NATURALIST," which likewise contains _Three Engravings_ of very curious subjects in other departments of Natural History. * * * * * CONVERSATIONS ON GEOLOGY. We have already spoken in favourable terms of this volume. It consists of 15 conversations of a family circle, comprising a familiar explanation of the Huttonian and Wernerian systems; the Mosaic geology, as explained by Penn; and the late discoveries of Buckland, Humboldt, Macculloch, and others. By way of specimen, we take a portion of a conversation which introduces the very interesting subject of the _formation of coal_: _Edward_.--As the Huttonians evidently fail in proving coal to be produced by fusion, I hope the Wernerians may succeed better, for I should be sorry if so interesting a subject were left unexplained. _Mrs. R._--To understand their account, it will be requisite for you to recollect the process of the formation of bogs and marshes, as it is from these that Werner derives coal. What I told you, also, of the change produced on wood by being long exposed to moisture and kept from contact with the air, will be of use here, as wood, in all stages of change, is often found in coal-fields, in the same way as in peat-bogs. _Edward_. That is a very strong circumstance in favour of the alleged origin. _Mrs. R_. There are some facts, indeed, connected with this, which prove this origin beyond question, as you will admit, when I tell you that specimens of wood are often found partly converted into coal and partly unchanged, or petrified by some other mineral. _Edward_. This will, at least, be direct proof that wood may be converted into coal.