(This is certainly one of the most ingenious books of the season, and independently of its place as a volume of the Family Library, it has substantive claims which we trust will not he overlooked. It is from the graceful pen of Sir David Brewster, who possesses, in a high degree, the peculiar talent of investing scientific inquiries with the charm of popular delight; in short, of making science easy, and often conveying in a single chapter what others labour to effect in a volume. He, in truth, teaches us the sweet uses of science.
The present work appears to be the suggestion of Sir Walter Scott, to whom it is addressed in letters. We can give but a faint idea of the extent and interest of its subject, which ranges from the magic of the ancients to the intoxicating gas of the moderns; yet the purpose of the work is mainly to trace the connexion of those prodigies of the material world which are termed Natural Magic, with scientific causes. Thus, in the introductory letter, the writer observes on the resources of ancient magic:—)
The secret use which was thus made of scientific discoveries and of remarkable inventions, has no doubt prevented many of them from reaching the present times; but though we are very ill informed respecting the progress of the ancients in various departments of the physical sciences, yet we have sufficient evidence that almost every branch of knowledge had contributed its wonders to the magician's budget, and we may even obtain some insight into the scientific acquirements of former ages, by a diligent study of their fables and their miracles.
(In the second letter, upon Ocular Illusions, is the following beautiful passage on the Eye:—)
This wonderful organ may be considered as the sentinel which guards the pass between the worlds of matter and of spirit, and through which all their communications are interchanged. The optic nerve is the channel by which the mind peruses the hand-writing of Nature on the retina, and through which it transfers to that material tablet its decisions and its creations. The eye is consequently the principal seat of the supernatural. When the indications of the marvellous are addressed to us through the ear, the mind may be startled without being deceived, and reason may succeed in suggesting some probable source of the illusion by which we have been alarmed. But when the eye in solitude sees before it the forms of life, fresh in their colours and vivid in their outline; when distant or departed friends are suddenly presented to its view; when visible bodies disappear and reappear without any intelligible cause; and when it beholds objects, whether real or imaginary, for whose presence no cause can be assigned, the conviction of supernatural agency becomes under ordinary circumstances unavoidable. Hence it is not only an amusing but an useful occupation to acquire a knowledge of those causes which are capable of producing so strange a belief, whether it arises from the delusions which the mind practises upon itself, or from the dexterity and science of others.
(The Optical phenomena, as might be expected, are most abundant, as they include the subject of spectral illusions and apparitions, and natural phenomena marked with the marvellous. The properties of Sound are next in interest; among them we find explained the wonder of singers breaking glasses with their great power of voice; the automaton flute-player, talking engines, echoes, &c. The Mechanical causes are less numerous: among them we are glad to see noticed the feat of lifting heavy persons, which we ourselves have often seen accomplished; but Sir David Brewster does not supply the cause. As the matter may be new to many readers, we quote the two relating pages.)
One of the most remarkable and inexplicable experiments relative to the strength of the human frame, which you have yourself seen and admired, is that in which a heavy man is raised with the greatest facility, when he is lifted up the instant that his own lungs and those of the persons who raise him are inflated with air. This experiment was, I believe, first shown in England a few years ago by Major H., who saw it performed in a large party at Venice under the direction of an officer of the American Navy. As Major H. performed it more than once in my presence, I shall describe as nearly as possible the method which he prescribed. The heaviest person in the party lies down upon two chairs, his legs being supported by the one and his back by the other. Four persons, one at each leg, and one at each shoulder, then try to raise him, and they find his dead weight to be very great, from the difficulty they experience in supporting him. When he is replaced in the chair, each of the four persons takes hold of the body as before, and the person to be lifted gives two signals by clapping his hands. At the first signal he himself and the four lifters begin to draw a long and full breath, and when the inhalation is completed, or the lungs filled, the second signal is given, for raising the person from the chair. To his own surprise and that of his bearers, he rises with the greatest facility, as if he were no heavier than a feather. On several occasions I have observed that when one of the bearers performs his part ill, by making the inhalation out of time, the part of the body which he tries to raise is left as it were behind. As you have repeatedly seen this experiment, and have performed the part both of the load and of the bearer, you can testify how remarkable the effects appear to all parties, and how complete is the conviction, either that the load has been lightened, or the bearer strengthened by the prescribed process. At Venice the experiment was performed in a much more imposing manner. The heaviest man in the party was raised and sustained upon the points of the fore-fingers of six persons. Major H. declared that the experiment would not succeed if the person lifted were placed upon a board, and the strength of the individuals applied to the board. He conceived it necessary that the bearers should communicate directly with the body to be raised. I have not had an opportunity of making any experiments relative to these curious facts; but whether the general effect is an illusion, or the result of known or of new principles, the subject merits a careful investigation.
(In connexion with walking along the ceiling is noticed the beautiful contrivance of the foot of the house-fly and gecko, and the head of the sucking-fish. To the next portion, Chemistry has supplied fewer wonders than we expected: they occupy but fifty pages.
The examples in this book are the most quotable portion, but the majority of them would be new to few readers: who, for instance, is unacquainted with the feats of Topham, the strong man, or the Invisible Girl. The explanations are not so easily transferable, since they are generally accompanied by illustrations.
By the way, how many of these wonders are recorded in the early volumes of the Philosophical Transactions, with all the gravity of the FF.R.S. whose zeal, industry, and emulation rendered the early years of the Society peculiarly brilliant. The very titles of some of the early papers would make a "wonderful museum;" as Four Suns observed in France—Worms that eat Stones and Mortar—which are almost as marvellous as one of Sir David Brewster's lines—a coach and four filled with skeletons. The Royal Society has now existed a century and three-quarters: in their early Transactions are inquiries relative to the tides—observations on the darting threads of spiders—"experiments about respiration"—"of red snow seen at Genoa," &c.; yet scores of philosophers, at the present moment, are controverting these very subjects.)