I do not think there would be sufficient time between these periods for accomplishing the objects you mention; nor do I think myself qualified to write upon the agriculture of a county. I wished likewise to devote the leisure of this summer to the preparation of my lectures on the Chemistry of Agriculture for publication. I have a great deal of information concerning the mineralogy and geology of Cornwall, but none concerning the farming. If the business admits of being postponed, I might perhaps be able to accomplish it next summer; that is, by devoting a part of this summer, and the whole of my next: but I would rather confine myself to my own province, the mineralogy and geology of the county, and leave the agriculture to abler hands. Be pleased to receive my thanks, and to communicate them to the President for the honour of the proposal. I remain, &c. H. DAVY. The majority of my readers will probably concur in the wisdom of this decision: they will consider that to have doomed Davy to a drudgery of this nature, would have been wasting talents upon an object which might be accomplished by smaller means. From my acquaintance, however, with Cornwall, I am induced to form a different opinion. Davy never approached even those subjects which had already received from others the most thorough investigation, without extracting from them new and important truths. What, then, might not have been expected from his genius, when applied to a department upon which the light of science had scarcely dawned? It is only in a primitive country like Cornwall, that the natural relations between the varieties of soil and the subjacent rocks can be studied with success: as we advance to alluvial districts, such relations become gradually less distinct and apparent, and are ultimately lost in the confused complication of the soil itself, and in that general obscurity which envelopes every object in the ulterior stages of decomposition. We can, therefore, only hope to succeed in such an investigation by a patient and laborious examination of a primitive country, after which we may be enabled to extend our enquiries with greater advantage through those regions which are more completely covered with soil, and obscured by luxuriant vegetation; as the eye, acquainted with the human figure, on gazing upon a beautiful statue, traces the outline of the limbs, and the swelling contour of its form, through the flowing draperies which invest it. The importance of the subject, as well as the general interest it has excited, induce me to offer an analysis of his "Elements of Agricultural Chemistry." The work is divided into eight lectures; and in his introductory chapter, after adverting to the difficulties which the enquiry presents to the lecturer, he offers a general view of the objects of the course, and of the order in which he proposes to discuss them.