PREFACE. THE Author of the following Essay would have been content, as the reward of his labour, with the premium awarded to him in the Diocese of St. David's, without obtruding himself upon the notice of the public, had not the solicitations of his more immediate friends, (a fact not the less true, because so frequently the author's plea, but which he might have been tempted to overlook as arising from their partiality,) been united with an intimation from the individual from whom the premium originated, that the publication of the Essay would be acceptably regarded; and this compelled him to surrender, though with considerable reluctance, his own wishes to the opinion of others. Being thus brought before another tribunal, at which he naturally feels that sort of apprehension which accompanies a first appearance, he deems it but justice to himself to premise some of the circumstances under which the Essay was written, if not to excuse its errors, yet at least to induce a milder tone in the observations of those who may detect and expose them. The subject, then, as thrown out for general investigation, was not seen by the Author till a considerable part of the period had elapsed within which the rival Essays were to be completed. That period was the latter end of July, 1821; and it was not till the beginning of June preceding, that the Author commenced his preliminary investigations, and those under no slight disadvantages. That period, the close of Easter and the commencement of Trinity Terms, more than ordinarily demanded his attention in his professional pursuits. His chief time for labour, therefore, was during the night; and the fatigues of a long day, when encountered by a constitution of not the stoutest texture, not unfrequently compelled him to relinquish his undertaking; one motive, however, stimulated him to revive it; and that |