As natural sleep has different degrees of profoundness, so has trance sleep. They present a latitude so extensive, that it is convenient and allowable to lay down three different degrees or states of trance-sleep. Then, of trance-sleep first, and of its three degrees. The deepest grade of trance-sleep extinguishes all the ordinary signs of animation. It forms the condition in which many are buried alive. It is the so-called vampyr state in the vampyr superstition. [See Letter II. of this series.] The middle grade presents the appearance of profound unconsciousness; but a gentle breathing and the circulation are distinguishable. The body is flexible, relaxed, perfectly impassive to ordinary stimuli. The pupils of the eyes are not contracted, but yet are fixed. This state is witnessed occasionally in hysteria, after violent fits of hysteric excitement. In the lightest degree of trance-sleep, the person can sustain itself sitting; the pupils are in the same state as above, or natural; the apparent unconsciousness profound. Two features characterise trance-sleep in all its grades. One, an insensibility to all common stimulants, however violently applied; the other, an inward flow of ideas, a dream or vision. It is as well to provide all words with a precise meaning. The term vision had better be restricted to mean a dream during trance-sleep. The behaviour of Grando, who had been buried in the vampyr state, when they were clumsily cutting his head off, makes no exception to the first of the above positions. He had then just emerged out of his trance-sleep, either through the lapse of time, or from the admission of fresh air, or what not. It will not be doubted that the mind may have visions in all the grades of trance-sleep, if it can be proved capable of them in the deepest; therefore, one example will suffice for all three cases. Henry Engelbrecht, as we learn in a pamphlet published by himself in the year 1639, after a most ascetic life, during which he had experienced sensorial illusions, was thrown for a brief period into the deepest form of trance-sleep, which event he thus describes:--