PREFACE.

THE present Treatise is an attempt to supply what has hitherto been a desideratum in English literature, viz. a complete account of Sleep. The undertaking, though not very extensive, has been more difficult than would, at first sight, be imagined, owing chiefly to the extreme diversity of opinion that exists with regard to the nature of Sleep. There is scarcely a single fact on which any two authors agree; nor does this difference extend merely to the metaphysical consideration of the subject, for the medical writers are, in every respect, as much divided in their views as the metaphysicians, and the most contradictory statements meet us at almost every step. Under such circumstances, the Author is far from supposing that he has produced any thing like a perfect history of Sleep, but he has endeavoured to do so as far as lay in his power, both by appealing to his own observation, and to the experience of other writers. With regard to the theory pervading the work, opinions, of course, will vary. It has been

adopted, not only as being in itself more probable than the prevailing' doctrines of the schools, but as affording an easier explanation of all the phenomena of Sleep than any other with which he is acquainted.

Of the cases which have been introduced, some are drawn from sources not very accessible, and a number are now published for the first time. For two very singular cases of the latter description, he is indebted to the kindness of a distinguished friend, Mr. Moir of Musselburgh. On every disputed fact, he has adopted that opinion which his own observation pointed out as corre and wherever this was deficient, he has been guided by analogy. It is probable that the view taken of the nervous system, may be objected to by some readers; in answer to which, it may be stated, that this hypothesis, besides being rendered probable by the strongest evidence, is now very generally adopted by the Continental physiologists. In France, it is almost universally taught in the medical schools, and is gaining ground so fast in Great Britain, that, in a few years, it will, in all probability, be as firmly established here as on the Continent.

GLASGOW, 25th September, 1830.