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to make it into two volumes instead of one. That which was the first part now appears as a separate volume, confined to the physiology of mind; and will be followed by its sequel, or companion-work, as a separate treatise on mental pathology. It is an excellent thing on every account to divide the original work in this way, for, although the subjects are most intimately connected, they can be just as well studied together now as before, while there will unquestionably be many who will care chiefly for but one of the volumes. That now issued has an interest for all students of the philosophy of mind, while the one following will more directly concern the medical profession. "The Physiology of Mind" by Dr. Maudsley is a very engaging volume to read, as it is a fresh and vigorous statement of the doctrines of a growing scientific school on a subject of transcendent moment, and, besides many new facts and important views brought out in the text, is enriched by instructive notes and quotations from authoritative writers upon physiology and psychology, and by illustrative cases which add materially to the interest of the book. We have room for but one of these, showing the manner in which the loss of one sense is followed by an extension or increase of function of those which remain:

"Many years ago application was made to Dr. Howe, of the Massachusetts Asylum for the Blind, by a locksmith for the 'loan' of a blind boy, as he said, who had quick ears and a silent mouth. On giving satisfactory answers he got his loan. He wanted a boy to help him open a new and complicated lock. An inventor exhibited a locked safe and the key, saying that there was money within, which should be given to whoever could open the lock without deranging it. The peculiarity of the lock was, that it had ten bolts, which, from all that could be ascertained, seemed exactly alike, but in reality one of them was an inch longer than the others, so that, when all were thrown forward, that one alone held the door closed. The key would lift any of the ten bolts; but in order to open the safe it must be applied to the long bolt, and to that only, and that one must he lifted and turned back in order to open the lock; but if any other of the ten were lifted and turned back ever so little, it deranged the combination, and the lock could only be opened by a peculiar instrument. The object, then, was to ascertain which of the ten was thrown forward without turning back any other one.

"The mechanic lifted each bolt carefully with the key, and let it fall, but without trying to throw it back; and he then tried to ascertain if in falling it made any peculiar noise; for he inferred that, as the only one which held the door was an inch longer than the others, it must fall with a slightly greater force; but the difference was too slight for his ear. He took the blind lad, and asked him to listen carefully to the sound which each bolt made as he lifted and let it fall. After listening to each intently, the lad said the sixth one struck a little the loudest. The mechanic lifted and let each one fall carefully several times, and each time the boy insisted that the sixth bolt sounded the loudest. Upon this the mechanic lifted and turned back the sixth, and the lock was opened without the combination being deranged."

No library of mental philosophy will be complete without this book, and no liberal student of the subject can refrain from giving it his serious and critical attention.

A Practical Treatise on Lightning-Protection. By Henry W. Spang. 12mo. Pp. 180. With Illustrations. Philadelphia: Claxton, Remsen & Haffelfinger. 1877. Price, $1.50.

The above book contains the result of the author's observation and study on the subject of lightning-protection during an eighteen years' experience in the telegraph business. After an introductory course of experiment with artificial lightning, and an explanation of the principal known facts relating to the electricity of the earth and atmosphere, the author proceeds to show that few of the lightning-rods or conductors now erected can be relied upon for an easy passage of heavy lightning-discharges, and goes on to prove that the metal roof and rain-pipes of a building can be made a better protection at a reduced expense. Explicit directions then follow for the protection of buildings of every description, ships, oil-tanks, steam-boilers, bridges, telegraph-poles, etc.

Notes upon the Lithology of the Adirondack. By Albert R. Leeds. Pp. 35. From the American Chemist.

Prof. Leeds does not assume to present a complete lithology of the Adirondack region, but limits himself to giving an outline of the work already done in that field: a description of the rocks so far collected by himself; analyses of some of the more important typical rocks and minerals; results of microscopic study of rock-sections; and, finally, inferences drawn from these premises.