The muscular coat is scarcely ever proved (by cadaveric examination), to be primarily affected; the disease almost invariably arises in the mucous and the submucous cellular tissue, and involves the former secondarily; we are, therefore, the more limited to a consideration of the affections of the mucous and the submucous cellular tissues, as they demand a minute investigation on account of their extreme importance.

We may infer the general importance of this branch of pathology from the rank the mucous membrane occupies in the domestic economy, from the consequent frequency, and the variety in the forms of its idiopathic affections, but more especially from the frequency of the secondary complications to which it is subject, from the numerous relations which it bears to other systems and organs, and the fluids at large.

We introduce the subject of inflammation by a preliminary consideration of the hyperaemic and anaemic states of the mucous membrane.