After offering so copious an analysis of Dr. AYRE'S sentiments respecting the pathology of dropsy, it is unnecessary to enlarge very fully on the application of his theory to the particular forms of that disease. We shall, however, offer a rapid review, of some of his opinions, and next detail the method of treatment he proposes for the cure of these dangerous maladies. We commence with hydrocephalus, which he remarks has been divided into an acute and chronic form. This division, our author thinks, is correct in a certain sense; for the disease varies much in duration,--running its course, sometimes in a few days; and at other times continuing several weeks. Yet, he continues, the terms acute and chronic must be understood as restricted to that particular form of inflammation producing a serous effusion, and not as denoting the highest and lowest degrees of common inflammation. It is from the want of this distinction that much confusion has arisen in our speculations relative to the pathology of hydrocephalus. Dr. AYRE calls our attention to the fact, that the forms of hydrocephalus denominated by Dr. GOLIS hyperacute and acute, do not differ from the sub-acute phrenitis of nosologists, in which pus and coagulable lymph are the proper products, with sometimes a serous effusion into the ventricles as an accidental effect; all of which forms of inflammation, the serous membranes of the brain, and of other cavities are liable to take on; and adds: "Now, the true hydrocephalus internus stands distinguished from these, in the nature of the inflammation of which it consists, in the same way, precisely, that the serous inflammation of the pleura, producing simple hydrothorax, is distinct from that higher degree of vascular excitement, which occasions an effusion of pus or lymph. Relatively to these, therefore, the disease is in a chronic form; and consists, we may repeat, of that lowest degree of inflammation to which serous membranes are subject, and the effect of which is to increase the natural secretion of the part, so as to cause, in regard to the brain, an accumulation of that fluid in its cavities."