In a former number I was led to draw attention to the distinctive meaning of illusions, hallucinations, and delusions, in consequence of the confusion manifested in the medical evidence given at a late celebrated trial, and from observing a like confusion in most of our works on mental medicine. And without entering into the physiological or psychological nature of these phenomena, I endeavoured to point out the plain, simple, and efficient characteristic, that illusions and hallucinations were the morbid phenomena of perception, the former occurring with, the latter without any external or objective cause; and that delusion was the result of morbid conception. In the following remarks, I wish to point out the distinctive features of those faculties whose morbid phenomena are designated by the above three terms, particularly the distinction between sensation and perception; for the confusion existing relative to the phenomena, healthy or morbid of any faculty does and must result from that faculty in its nature and limits being badly and confusedly apprehended, and therefore requiring a further analysis and more decided definition; a confusion which, relative to our subject, has led some in the present day to locate the faculty of perception, independent of sensation, in the nerves and organs of special sense; (see the Annales Psychulogiques.)