Before taking leave of Dr. AYRE, we cannot omit adverting, in a very few words, to a circumstance noticed in his preface, and which we think of some importance. He remarks, that if, in the prosecution of his task, he has had no acknowledgments to make to any individual as his guide and authority, he is nevertheless indebted for many important facts to the writings of the late Dr. WELLS, and of Drs. BLACKALL, ABERCROMBIE, and DUNCAN, jun. and particularly to the system of pathology of Dr. PARRY. He further remarks, that he entertained and taught for many years, the views advocated in this work, and that, after the manuscript had been sent to press, he had seen a copy of an abridged edition of the elaborate Dictionnaire des Sciences Medicales, in which the doctrine of dropsy, maintained in the larger work, is relinquished; whilst others are given in their place, conformable, in the main, with those which it is the object of his treatise to establish. Now it would appear, from these expressions, that Dr. AYRE wishes to inculcate the idea, that the English writers, whom he has cited, were the only ones who had published anything valuable, and conformable to his doctrine; and that prior to 1823, the year of the publication of the Dictionary above mentioned, the French entertained very different views of the pathology of the disease. We think it our duty, however, to rectify our author in this respect, and to show to our readers, that, even allowing full credit to Drs. WELLS, BLACKALL, ABERCROMBIE, &c. for their researches into the nature and treatment of dropsy, the American, French, and Italian pathologists are entitled to a much larger share than is allowed to them in the present work. A few references will be sufficient. Many years ago, our celebrated RUSH taught, that general dropsies "depend on a certain morbid excitement of the arteries;" and that hydrocephalus, "in its first stage, is the effect of causes, which produce a less degree of that morbid action in the brain which constitutes phrenitis." In 1812, Dr. BRESCHET, of Paris, published an excellent dissertation on active dropsies. In the early writings of BROUSSAIS, though more particularly in the propositions prefixed to his _Examen_, the opinion is maintained, that all active dropsies depend on irritability, either primary or secondary, of the serous and cellular tissues,--a theory more closely allied to Dr. A.'s, than all that is contained in the writings of Drs. WELLS, PARRY, &c. But what, perhaps, is more to our purpose, Dr. GEROMINI, of Cremona, published a work, in 1816, on the origin and cure of dropsy, in which he compares the dropsical accumulation to that of serum produced by the inflammation of a blister, or by fire; and in which he also maintains, that a slight inflammation occasions a flow of limpid serous fluid, whilst a higher degree gives rise to the formation of pus. From these circumstances, he concludes, that the hydropic fluid,