ΤΟ HIS GRACE THE ARCHBISHOP OF CANTERBURY. MY LORD, HAVING been appointed to write the following Treatise by the late President of the Royal Society, in consequence of your Grace's recommendation, it was natural that I should be desirous of publickly acknowledging the high honour thus conferred upon me. I therefore request you to accept my respectful thanks for permitting me to inscribe this Treatise with your Grace's name: assuring you that, however inadequately I may have been found to answer your expectation in the execution, I have not applied myself to the task committed to me, without the exertion of much thought, and the strongest desire of so executing it, as to justify your Grace's favourable opinion. I have the honour to be, MY LORD, with the greatest respect, Your Grace's most obliged and obedient Servant, J. KIDD. Oxford, March 15, 1833. PREFACE. THE occasion which gave rise to this and the accompanying Treatises is explained in the following notice but the Author of the present Treatise thinks it right to add, that, although encouraged by the honour of having been recommended by His Grace the Archbishop of Canterbury, he should have shrunk from his present attempt, had he considered that any exact elucidation of the details of science was required in the execution of it. As, however, the intention of Lord Bridgewater, and the very extent and diversified nature of the subject, seemed to him almost necessarily to exclude any great exactness of elucidation, and to require a popular rather than a scientific exposition of facts; and as the whole tenour of his pursuits during the last thirty years of his life accorded with the character of the proposed subject; he the more readily undertook a task, to the execution of which he could not but look forward with much pleasure. And if he should in any instance stimulate the reader to examine the question with any portion of the interest and satisfaction with which he has himself examined it, he is confident that he shall not have laboured in vain. It will be for others to determine whether a judicious selection and a sufficiently natural arrangement of the materials of the following Treatise have been adopted: but to those, who may think that many of the subjects have been treated too cursorily, the Author begs leave to point out the extensive range afforded by so wide a field of inquiry; and the consequent necessity of compression in each particular; the subject of this Treatise being in fact an epitome of the subjects of almost all the others. He also considers it right to state, that it is the immediate object of the Treatise itself to unfold a train of facts, not to maintain an argument; to give a general view of the adaptation of the external world to the physical condition of man, not to attempt formally to convince the reader that this adaptation is a proof either of the existence |