have discovered the last and the most precious application of all our knowledge.

It would be an unprofitable labour to enter into an examination of the manner in which Dr. Abercrombie has analysed the ordinary operations of the mind. The subject admits of little novelty, and, therefore, cannot possess any peculiar interest for the general reader. We shall, therefore, proceed to that part of the work in which the author's knowledge as a medical philosopher and his extensive practice as a physician is more distinctly marked.

In treating of the use of reason in correcting the impressions of the mind in regard to external things-an almost untrodden field of inquiry-Dr. Abercrombie discusses the curious subjects of dreaming, insanity, somnambulism, and spectral illusions, and illustrates his views by various interesting and authentic facts. He regards insanity and dreaming as having a remarkable affinity considered as mental phenomena, the erroneous impressions in the former being permanent and affecting the conduct, while, in the latter, the impression is transient, and has no permanent influence on the conduct: in the former, the bodily senses are alive to external impressions, and the motions of the body are under the influence of the will; while, in the latter, the bodily senses are, in a great measure, closed against external impressions, and the influence of the will upon bodily motions is in general suspended. He regards somnambulism as an affection intermediate between insanity and dreaming. It differs from the former in the circumstance, that the somnambulist can be roused from his vision, and from the latter, in the senses being, to a certain degree, awake to external things. The phenomenon of spectral illusions partakes in the character of all these affections of the body.

In discussing the subject of dreams, Dr. Abercrombie comfines himself principally to an investigation of the manner in which the particular visions arise, and in this respect he arranges dreams into four classes. 1. When recent events and recent mental emotions are mixed up with each other, and with old events by some feeling common to both. Although this kind of dream is extremely common, we may quote a curious example of it given by Dr. Abercrombie.

'A woman who was a patient in the clinical ward of the Infirmary of Edinburgh, under the care of Dr. Duncan, talked a great deal in her sleep, and made numerous and very distinct allusions to the cases of other sick persons. These allusions did not apply to any patients who were in the ward at that time; but after some observation, they were found to refer correctly to the cases of individuals who were there when this woman was a patient in the ward two years before.'

2. The second class of dreams relate to trains of images brought

up

up by association with bodily sensations. As examples of this numerous class, Dr. Abercrombie mentions the case of Dr. Gregory, who, in consequence of having a vessel of hot water at his feet, dreamt of walking up the crater of Mount Etna, and feeling the ground warm beneath him; and on another occasion, when the bed-clothes were thrown off him, he dreamt of being at Hudson's Bay, and of enduring much distress from the cold. At another time, when suffering from tooth-ache, he dreamt of undergoing the operation of tooth-drawing, with the additional circumstance that the dentist drew a sound tooth and left the aching one in its place. Dr. Reid also dreamt of being scalped by savages in consequence of the uneasiness which he experienced from the dressing of a blister upon his head having been ruffled during sleep.

Dreams are frequently produced by loud sounds; and Dr. Abercrombie quotes a case from a manuscript of Dr. Gregory, where the same sound produced simultaneously in a man and his wife a dream of the same general character, viz. that the French had landed near Edinburgh, an event which at the time was a subject of general anxiety. The most remarkable example, however, of this kind of dreaming is given by the same great physician in the manuscript referred to, and on the authority of an eyewitness.

The subject of it,' says Dr. Abercrombie,' was an officer in the expedition to Louisburg, in 1758, who had this peculiarity in so remarkable a degree, that his companions in the transport were in the constant habit of amusing themselves at his expense. They could produce in him any kind of dream by whispering into his ear, especially if this was done by a friend with whose voice he was familiar. At one time they conducted him through the whole progress of a quarrel, which ended in a duel; and when the parties were supposed to be met, a pistol was put into his hand, which he fired, and was awakened by the report. On another occasion they found him asleep on the top of a locker or bunker, in the cabin, when they made him believe he had fallen overboard, and exhorted him to save himself by swimming. He immediately imitated all the motions of swimming. They then told him that a shark was pursuing him, and entreated him to dive for his life. He instantly did so with such force as to throw himself entirely from the locker upon the cabin floor, by which he was much bruised, and awakened of course. After the landing of the army at Louisburg, his friends found him one day asleep in his tent, and evidently much annoyed by the cannonading. They then made him believe that he was engaged, when he expressed great fear, and showed an evident disposition to run away. Against this they remonstrated, but at the same time increased his fears by imitating the groans of the wounded and the dying; and when he asked, as he often did, who was down, they named his particular friends. At last they told him that the man next

himself

himself in the line had fallen, when he instantly sprung from his bed, rushed out of the tent, and was roused from his danger and his dream together by falling over the tent ropes. A remarkable thing in this case was, that after these experiments he had no distinct recollection of his dreams, but only a confused feeling of oppression or fatigue; and used to tell his friends that he was sure they had been playing some trick upon him.'

s. The third class of dreams relates to the revival of forgotten associations. The following case, given by Dr. Abercrombie, occurred to a particular friend of his own, and he assures us that it may be relied on in the most minute particulars.

'The gentleman was at the time connected with one of the principal banks in Glasgow, and was at his place at the tellers' table where money is paid, when a person entered, demanding payment of a sum of six pounds. There were several people waiting, who were, in turn, entitled to be attended to before him, but he was extremely impatient, and rather noisy; and being besides a remarkable stammerer, he became so annoying, that another gentleman requested my friend to pay him his money and get rid of him. He did so accordingly, but with an expression of impatience at being obliged to attend to him before his turn, and thought no more of the transaction. At the end of the year, which was eight or nine months after, the books of the bank could not be made to balance, the deficiency being exactly six pounds. Several days and nights had been spent in endeavouring to discover the error, but without success, when at last my friend returned home, much fatigued, and went to bed. He dreamt of being at his place in the bank, and the whole transaction of the stammerer, as now detailed, passed before him in all its particulars. He awoke under the full impression that the dream was to lead him to the discovery of what he was so anxiously in search of; and, on examination, he soon discovered that he had neglected to enter the sum which he had paid to this person in the manner now mentioned, and which exactly accounted for the error in the balance.'

Dr. Abercrombie considers this case as one of the most remarkable mental phenomena connected with dreaming, and he confesses himself incapable of conceiving upon what principle the neglect of entering the money was recalled, as there was no consciousness at the time of any such fact, the importance of the case resting not upon his having paid the money, but upon his having neglected to insert the payment. To our apprehension, the difficulty does not appear to be so great; the teller did not recall in his dream the fact of his having omitted to insert the payment; he only recalled the whole transaction with the stammerer, and he awoke with an impression merely that the dream would lead to the discovery of the error. During his waking exertions to detect the cause of his mistake, he may perhaps never have recollected

the

the transaction with the stammerer, and therefore we can, on this hypothesis, easily understand how the dream, by recalling that transaction, induced him to examine the books relative to an individual payment which he had forgotten. But even if the transaction with the stammerer had been fully in his mind during the day, along with others which he remembered equally well, the dream was sufficient to fix his mind more upon that transaction than upon any other, and thus to lead him to a particular examination of it. If we suppose the teller to have had the smallest degree of superstitious feeling on the subject of dreams, it is easy to conceive how he had, when awake, the full impression that the dream was to lead to the discovery of his error.

4. The fourth class of dreams contains those in which a strong propensity of character, or a strong mental emotion, is embodied in a dream, and by some natural coincidence is fulfilled. The following cases are given by Dr. Abercrombie as examples of this variety :

A clergyman had come to Edinburgh from a short distance in the country, and was sleeping at an inn, when he dreamt of seeing a fire, and one of his children in the midst of it. He awoke with the impression, and instantly left town on his return home. When he arrived within sight of his home, he found it on fire, and got there in time to assist in saving one of his children, who, in the alarm and confusion, had been left in a situation of danger.

A gentleman in Edinburgh was affected with aneurism of the popliteal artery, for which he was under the care of two eminent surgeons, and the day was fixed for the operation. About two days before the time appointed for it, the wife of the patient dreamt that a change had taken place in the disease, in consequence of which the operation would not be required. On examining the tumour in the morning, the gentleman was astonished to find that the pulsation had entirely ceased; and, in short, this turned out to be a spontaneous cure. To persons not professional, it may be right to mention, that the cure of popliteal aneurism without an operation is a very uncommon occurrence, not happening, perhaps, in one out of numerous instances, and never to be looked upon as probable in any individual

case.'

The following still more remarkable dream is given by Dr. Abercrombie as entirely authentic :

A lady dreamt that an aged female relative had been murdered by a black servant, and the dream occurred more than once. She was then so impressed by it, that she went to the house of the lady to whom it related, and prevailed upon a gentleman to watch in an adjoining room during the following night. About three o'clock in the morning, the gentleman, hearing footsteps on the stair, left his place of concealment, and met the servant carrying up a quantity of coals.

Being

Being questioned as to where he was going, he replied, in a confused and hurried manner, that he was going to mend his mistress's fire,— which, at three o'clock in the morning, in the middle of summer, was evidently impossible; and, on further investigation, a strong knife was found concealed beneath the coals.'

Dr. Abercrombie has assigned some ingenious and plausible reasons why the clergyman might dream of his house being on fire, and why the lady dreamt that the operation might be dispensed with; but even if we admit the force of these reasons, we must consider the coincidence of the dreams with the events as still inexplicable. In the second case, the dream produced no obvious good effect, but in the first and third cases a life was saved, and it is not easy to convince ourselves that the coincidences were in these instances purely accidental.

The object and limits of Dr. Abercombie's work have not permitted him to enter upon the investigation of the question respecting the origin of dreams, certainly one of the most important in the philosophy of the mind. We need scarcely wonder at the crude speculations which have been hazarded on this subject, wheu we consider that the study of it has seldom been conjoined with that of human physiology, and that it has never been submitted to the grasp of inductive research.

Among the numerous theories of dreaming there are two which more or less include all others. The first of these supposes that dreams originate wholly in direct impressions on some of the senses during sleep, while the second ascribes them to the supremacy of the mind, which being, to a certain extent, unfettered by objects of sense, takes a wider range, and occupies itself with its own operations.

The first of these opinions has been maintained by Formey, Wolfius, Hobbes, and Haller, and has received the general support of metaphysicians. If it is correct, dreams can be produced only by an external action on some of the senses, or by an internal action on the nerves occasioned by indigestion, fulness of blood, or some diseased condition of the system; and therefore they cannot take place when the body is in perfect health and sleeps undisturbed by external causes. We are disposed to think that there are facts which contradict this hypothesis; but whether this be the case or not, the question is capable of being submitted to a rigorous examination. If we find, for example, that persons dream who enjoy the soundest sleep, and who are believed by themselves and others to be in perfect health, we must consider the theory of external excitation as at variance with facts; but if it is found, on the other hand, that such persons are never sensible of dreaming, it would not decidedly follow that they do not dream,

because