THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 The JOHN J. and HANNA M. McMANUS 
 
 MORRIS N. and CHESLEY V. YOUNG 
 
 Collection 
 
LETTERS ON NATURAL MAGIC, 
 
 ADDRESSED TO 
 
 SIR WALTER SCOTT, BART. 
 
 BY 
 
 SIE DAVID BREWSTER, K.E. 
 
 M,.D., F.R.S., V.P.R.S.E., ETC., ETC. 
 
 WITS INTRODUCTORY CHAPTERS ON THE BEING AND FACULTIES 
 
 OF MAN, AND ADDITIONAL PHENOMENA OF 
 
 NATURAL MAGIC. 
 
 BY 
 
 J. A. SMITH, 
 
 AUTHOR OF A TREATISE ON THE "STRUCTURE OF MATTER," ETC. 
 
 LONDON: WILLIAM TEGG. 
 
 1868. 
 
3 li 
 
 LOAlN ilACK 
 
 LONDON : 1>KINTE1> BV WILLIAM CLOWES AND SONS, STAMFORD STREET 
 AND CHARING CROSS. 
 
PEEFACE TO THE PEESENT EDITION. 
 
 SINCE the 24th of April, 1832, when the last of the accom- 
 panying Letters by Sir David Brewster to Sir Walter 
 Scott was written, many circumstances have occurred to 
 extend the importance of that wide and comprehensive 
 subject which Sir David has embraced under the name of 
 Natural Magic ; for though education, intelligence, and 
 scientific discovery have been advancing with rapid strides, 
 credulity has not been, and does not seem ever likely to 
 be, wholly eradicated by their means, while the ingenious 
 have been armed with immense and varied additional 
 elements to favour deception if they shall choose to employ 
 them for that purpose. It has appeared to the editor of 
 the present edition, therefore, of the highest importance 
 to give the work the benefit of that profounder interest 
 which must arise from a consideration of the physical and 
 metaphysical existence or being of man the union of 
 these two conditions of his being in their action, through 
 the faculties or powers of human perception and verifica- 
 tion, and also from a consideration of the range of natural 
 possibility ; for by a proper knowledge of these mankind 
 will be better aware of the extent of their liability to be 
 deceived, and of the means of verification and correction 
 at their command, as well as of the mode in which their 
 liability to deception ought to be guarded against or 
 
 849 
 
IV PBEFACE. 
 
 protected from the influence of imposture, and verification 
 applied in defeating or exposing delusion. 
 
 Much of the ease with which we are deceived by the 
 phenomena of natural magic arises from our want of 
 previous preparation, and our deficient knowledge, for the 
 moment, of the laws within which the true explanation of 
 these phenomena may be found. Hence, very much in pro- 
 portion to our ready knowledge or intelligence we are 
 either credulous or sceptical the words are used in a philo- 
 sophic sense merely ; and history has shown that men are 
 often quite as far from the truth in the extremity of their 
 scepticism as they are in the extreme of credulity itself. 
 Mere scepticism has in fact been a great barrier and 
 enemy to the progress of science ; and though the credulous 
 have often sunk into superstition and become intolerant, 
 they have more generally recognized than ignored those 
 temporarily incomprehensible facts which the advent of 
 calm science has satisfactorily explained. Indeed, but 
 for this slight difference,, these two extremes only too 
 often meet ; for the extreme of scepticism is credulity, and 
 the extreme of credulity, or superstition, is scepticism. 
 Both distrust truth ; both trust their own prejudices and 
 impressions rather than truth ; both misrepresent and 
 persecute it ; both obstruct the progress of its intelligible 
 development. Even in this day many facts of science 
 are, in consequence, left, without examination, in the hands 
 of charlatans whose function always is to render them 
 odious by exaggeration and therefore repugnant to 
 scientific study and explanation ; for the scientific mind 
 ever recoils from the wares of the quack, and too hastily 
 ignoring the small grain of genuine and philosophic truth 
 which is necessary and almost in every case present to 
 sustain any enduring pretension considers the whole 
 elements involved to be as much matters of imposture as 
 the individual by whom they are employed. This is 
 
PREFACE. V 
 
 barely excusable in a thinking age, and it is most certainly 
 not the way to disarm imposture or to put it down. If 
 the thinking and intelligent will not examine and explain 
 what is used to deceive, how can the unthinking and the 
 ignorant be but deceived, and continuously deceived, by it ? 
 Nay, we all know the experience of human weakness in 
 this respect to be such that the person whose credulity 
 has given way to deception in one case does not always, 
 where it has been rescued by explanation, resort to greater 
 caution and scepticism for the future, but, on the contrary, 
 that the idiosyncrasy of many individuals is to be deceived 
 in every instance in which competent explanation is want- 
 ing. Nor, even when caution and scepticism are produced 
 by detection of imposture, are these the great results which 
 philosophy and truth would desire to achieve. Intelligence 
 is the only bulwark of the human mind, and it is in 
 presence of this great and necessary adjunct to the integrity 
 of our normal being that the additions here made to Sir 
 David Brewster's excellent and popular work are now 
 offered to the public ; for the liability to be deceived, from 
 which we all more or less suffer, ought to be, not a 
 ground for scepticism, but only a stronger incentive to obey 
 that divine injunction : " GET KNOWLEDGE, GET WISDOM, 
 
 AND, WITH ALL THY GETTING, GET UNDERSTANDING." 
 
 From the nature of the case, as will be readily under- 
 stood, the eminent author's Letters have in themselves 
 been left intact, as an essential feature of their authenticity, 
 and the new matter has been introduced in the preliminary 
 and additional chapters. 
 
 From what is explained in the succeeding chapters, it 
 will be observed that comparison is the great means by 
 which we are enabled to assure ourselves, according to 
 the existing organization of our being, of the truth or 
 falsehood of any phenomenon, and that this comparison ex- 
 tends not only to the evidence of one faculty as compared 
 
VI PREFACE. 
 
 with another, but to the comparison afforded by different 
 points of examination in the use of the same faculty, so that 
 we may reasonably assume, where such verification is un- 
 fairly excluded, that we are entitled to suspend our judgment 
 in all cases in which immediate decision is not absolutely 
 necessary. But it is a singular fact in connection with 
 this subject that almost all animals are made with dupli- 
 cates of each of their faculties, as if to supply by com- 
 parison a check to the inaccuracy of the faculty within 
 itself. Thus we have duplicate brains as well as dupli- 
 cate eyes ; and while a man with two eyes sees with both, 
 and would detect imperfection in one eye by means of the 
 accuracy of the other, so we have reason to believe that a 
 man thinks in duplicate, or with both lobes of the brain, 
 although from the co-operation of the organs only one 
 single train of thought is apparent ; just as by the use of 
 both eyes one subject is alone presented in consequence 
 of the co-operation of both organs of vision : for it has 
 been found that where one of the lobes of the brain has 
 been so injured as to be incapable of action, a perfectly 
 sane and healthy power of mind has been maintained in 
 the individual by the sound action of the other lobe of the 
 brain only, just as accurate vision may be experienced by 
 a person having only one eye, or shutting the other. The 
 explanation of this power is not referrible to the physical, 
 but to the metaphysical part of our being, as will be better 
 understood by what we have introduced on the subject of 
 Consciousness ; for there is just as much a duplicate of 
 thought produced in employing both lobes of the brain as 
 there are two physical images when both eyes are used 
 the unity experienced in each case existing in the com- 
 bining power of the Consciousness only. 
 
 J. A. S. 
 Sept. 1868. 
 
CONTENTS. 
 
 THE BEING AND FACULTIES OF MAN IN EEFEEENCE 
 TO NATURAL MAGIC. 
 
 CHAPTER I. 
 
 PA OK 
 
 Material and immaterial nature of man Body Mind Life 
 Feeling External matter Touch Separation and con- 
 nection of all these Plato and the soul Electricity 
 Epicurus Bishop Berkeley David Hume Consciousness 
 and matter Consciousness and the immaterial Reciprocal 
 contact Man's primary perceptive power Its contact with 
 and knowledge of matter and the immaterial Its proximity 
 to the infinite Cause of the Epicurean error Berkeley's 
 blunder the other way Cause of Hume's error Self-de- 
 ception in philosophy Fallacy in a syllogism ... 1 
 
 CHAPTER II. 
 
 Consciousness as the primary perceptive faculty of our Being- 
 Its contact with reality and with all our impressions and 
 sensations of reality Eye and Ear more subject to in- 
 fluence from simulated impressions than the other senses 
 Touch and Taste possess more positive powers and means 
 of accuracy Smell intermediate in point of power Bishop 
 Berkeley and the Eye Not the Eye that requires educa- 
 tion from experience, but the Consciousness The Eye 
 perfect from the first Difference between the Conscious- 
 ness of man and of other animals Difference between 
 instinct and reason The Seat of Sensation Misapprehcn- 
 
Vlll CONTENTS. 
 
 PAGE 
 
 sions as to it Consciousness moves through our bodies 
 Capable of extension on surfaces Consciousness of space 
 Action of the senses not necessary to Consciousness in 
 them Power of Consciousness over the faculties Pleasure 
 and Pain Attention Thought Memory . . .19 
 
 CHAPTER III. 
 
 The senses the physical media of the Consciousness The 
 evidence of the senses of touch and taste Its impartiality 
 Its positiveness Evidence of the eye and ear compara- 
 tive and relative Co-operation of the senses without col- 
 lusionDistinctive perceptions or impressions of the 
 senses The current of ideas How stimulated Its im- 
 portance Our relative perception of hardness, size, weight, 
 colour, pitch of sound, &c. Our positive perception of 
 form Standards of comparison Size differently seen by 
 different individuals Erect vision and the inversion of 
 images on the retina Neither the true size nor true posi- 
 tion of objects presented to us by the eye Accuracy of the 
 eye Its superiority over photography A defect of photo- 
 graphy How caused Further remarks on comparison 
 Mirrors and mode of vision ...... 37 
 
 CHAPTER IV. 
 
 The limited range of our positive or absolute knowledge of 
 external matter How much our knowledge is merely 
 comparative How necessary, therefore, that we should 
 test everything where we can Difference in the mode in 
 which truth and falsehood demand our credence Spirit- 
 ualism and its seances Its profanation of the dead 
 Table-turning Faraday's exposure of it Simple appli- 
 cation of his indicator for the detection of unconscious 
 lateral pressure and of confederacy Mesmerism Its more 
 preposterous pretensions abated Our tendency to neglect 
 the true knowledge of what is familiar Our ignorance 
 of why or how our hands instantly obey our will 
 Consciousness can control and direct the operations of 
 matter Is it the force by which motion is accomplished ? 
 Probability that it is not The vital forces and the forces 
 of motion distinguished The blocd the life, a mystery 
 
CONTENTS. IX 
 
 PAGE 
 
 Electricity as a motive force in animals Probability of its 
 being the only motive force Structure of tbe muscles and 
 electric action 'on them Ampere's theory of electric cur- 
 rents Telegraphic and electro-mechanical nature of 
 animal motion ........ 56 
 
 CHAPTEE V. 
 
 Animal motion Spontaneous, involuntary and diseased motions 
 Capable of being artificially produced Defects in 
 Mesmerism Want of uniformity in its results Electro- 
 biology and Phrenology The brain Propensities 
 Cerebral development no proof of propensity Alleged 
 propensity not consistently shown in experience Pro- 
 pensity not material but metaphysical, and cannot be indi- 
 cated by size and quantity of matter Exercise causes 
 development Small mental power capable of great 
 achievements Accountability of human life Right and 
 wrong divide the universe Danger of error Tendencies 
 of the age Opinion Difference between Opinion and 
 Conviction Not necessary to form opinion as a basis of 
 action Opinion not truth An impediment to correct 
 action An illustration of this Case of an African 
 traveller Confusion as to opinion Our means of protec- 
 tion against error . . . . . . .71 
 
 [NATURAL MAGIC. 
 
CONTENTS. 
 
 LETTEES ON NATUKAL MAGIC. 
 
 LETTER I. 
 
 PAGE 
 
 Extent and interest of the subject Science employed by ancient 
 governments to deceive and enslave their subjects In- 
 fluence of the supernatural upon ignorant minds Means 
 employed by the ancient magicians to establish their 
 authority Derived from a knowledge of the phenomena of 
 Nature From the influence of narcotic drugs upon the 
 victims of their delusion From every branch of science 
 Acoustics Hydrostatics Mechanics Optics M. Sal- 
 verte's work on the occult sciences Object of the follow- 
 ing letters 89 
 
 LETTER II. 
 
 The Eye the most important of our organs Popular descrip- 
 tion of it The eye is the most fertile source of mental 
 illusions Disappearance of objects when their images fall 
 upon the base of the optic nerve Disappearance of objects 
 when seen obliquely Deceptions arising from viewing 
 objects in a faint light Luminous figures created by 
 pressure on the eye either from external causes or from 
 the fulness of the blood-vessels Ocular spectra or acci- 
 dental colours Remarkable effects produced by intense 
 light Influence of the imagination in viewing these 
 spectra Remarkable illusion produced by this affection of 
 the eye Duration of impressions of light on the eye 
 Thaumatrope Improvements upon it suggested Dis- 
 appearance of halves of objects or of one of two persons 
 Insensibility of the eye to particular colours Remarkable 
 optical illusion described ...... 95 
 
CONTENTS. XI 
 
 PAGE 
 
 LETTER III. 
 
 Subject of spectral illusions Recent and interesting case of 
 Mrs. A. Her first illusion affecting the ear Spectral 
 apparition of her husband Spectral apparition of a cat 
 Apparition of a near and living relation in grave-clothes 
 seen in a looking-glass Other illusions affecting the ear 
 Spectre of a deceased friend sitting in an easy-chair 
 Spectre of a coach and four filled with skeletons Ac- 
 curacy and value of the preceding cases State of health 
 under which they arose Spectral apparitions are pictures 
 on the retina The ideas of memory and imagination are 
 also pictures on the retina General views of the subject 
 Approximate explanation of spectral apparitions . . 120 
 
 LETTER IV. 
 
 Science used as an instrument of imposture Deceptions with 
 plane and concave mirrors practised by the ancients The 
 magician's mirror Effects of concave mirrors Aerial 
 Images Images on smoke Combination of mirrors for 
 producing pictures from living objects The mysterious 
 dagger Ancient miracles with concave mirrors Modern 
 necromancy with them, as seen by Cellini Description 
 and effects of the magic lantern Improvements upon it 
 Phantasmagoric exhibitions of Philipstal and others Dr. 
 Young's arrangement of lenses, &c., for the phantas- 
 magoria Improvements suggested Catadioptrical phan- 
 tasmagoria for producing the pictures from living objects 
 Method of cutting off parts of the figures Kircher's 
 mysterious handwriting on the wall His hollow cylindrical 
 mirror for aerial images Cylindrical mirror for reforming 
 distorted pictures Mirrors of variable curvature for pro- 
 ducing caricatures ....... 137 
 
 LETTER V. 
 
 Miscellaneous optical illusions Conversions of cameos into 
 intaglios or elevations into depressions and the reverse 
 Explanation of this class of deceptions Singular effects 
 of illumination with light of one simple colour Lamps 
 for producing homogeneous yellow light Methods of in- 
 creasing the effect of this exhibition Method of reading 
 
Xll CONTENTS. 
 
 PAG a 
 
 the inscription of coins in the dark Art of deciphering 
 the effaced inscription of coins Explanation of these 
 singular effects Apparent motion of the eyes in portraits 
 Remarkable examples of this Apparent motion of the 
 features of a portrait, when the eyes are made to move 
 Remarkable experiment of breathing light and darkness . 173 
 
 LETTER VI. 
 
 Natural phenomena marked with the marvellous Spectre of 
 the Brocken described Analogous phenomena Aerial 
 spectres seen in Cumberland Fata Morgana in the Straits 
 of Messina Objects below the horizon raised and magnified 
 by refraction Singular example seen at Hastings Dover 
 Castle seen through the hill on which it stands Erect and 
 inverted images of distant ships seen in the air Similar 
 phenomena seen in the Arctic regions- Enchanted coast 
 Mr. Scoresby recognizes his father's ship by its aerial image 
 Images of cows seen in the air Inverted images of horses 
 seen in South America Lateral images produced by re- 
 fraction Aerial spectres by reflection Explanation of 
 the preceding phenomena 198 
 
 LETTER VII. 
 
 Illusions depending on the ear Practised by the ancients 
 Speaking and singing heads of the ancients Exhibition of 
 the invisible girl described and explained Illusions arising 
 from the difficulty of determining the direction of sounds 
 Singular example of this illusion Nature of ventri- 
 loquism Exhibitions of some of the most celebrated ven- 
 triloquists M. St. Gille Louis Brabant M. Alexandre 
 Captain Lyon's account of Esquimaux ventriloquists . 224 
 
 LETTER VIII. 
 
 Musical and harmonic sounds explained Power of breaking 
 glasses with the voice Musical sounds from the vibration 
 of a column of air And of solid bodies Kaleidophone 
 Singular acoustic figures produced on sand laid on vibrat- 
 ing plates of glass, and on stretched membranes Vibration 
 of flat rulers, and cylinders of glass Production of silence 
 from two sounds Production of darkness from two lights 
 
CONTENTS. Xlll 
 
 PAGE 
 
 Explanation of these singular effects Acoustic automaton 
 Droz's bleating sheep Maillardet's singing bird 
 Vaucauson's flute-player His pipe and tabor player 
 Baron Kempelen's talking engine Kratzenstein's speak- 
 ing machine Mr. Willis's researches .... 244 
 
 LETTER IX. 
 
 Singular effects in nature depending on sound Permanent 
 character of speech Influence of great elevations on the 
 character of sounds, and on the powers of speech Power 
 of sound in throwing down buildings Dog killed by 
 sound Sounds greatly changed under particular circum- 
 stances Great audibility of sounds during the night ex- 
 plained Sounds deadened in media of different densities 
 Illustrated in the case of a glass of champagne, and in 
 that of new-fallen snow Eemarkable echoes Eeverbera- 
 tions of thunder Subterranean noises Eemarkable one 
 at the Solfaterra Echo at the Menai Suspension Bridge 
 Temporary deafness produced in diving-bells Inaudibility 
 of particular sounds to particular ears Vocal powers of 
 the statue of Memnon Sounds in granite rocks Musical 
 mountain of El-Nakous ...... 272 
 
 LETTEE X. 
 
 Mechanical inventions of the ancients few in number Ancient 
 and modern feats of strength Feats of Eckeberg particu- 
 larly described General explanation of them Eeal feats 
 of strength performed by Thomas Topham Eemarkable 
 power of lifting heavy persons when the lungs are inflated 
 Belzoui's feat of sustaining pyramids of men Deception 
 of walking along the ceiling in an inverted position 
 Pneumatic apparatus in the foot of the house-fly for 
 enabling it to walk in opposition to gravity Description of 
 the analogous apparatus employed by the gecko lizard for 
 the same purpose Apparatus used by the Echineis remora 
 or sucking fish . . .' . . \ V . 300 
 
 LETTEE XI. 
 
 Mechanical automata of the ancients Moving tripods Auto- 
 mata of Dsedalus Wooden pigeon of Archytus Auto- 
 matic clock of Charlemagne Automata made by Turrianus 
 
XIV CONTENTS. 
 
 PACK 
 
 for Charles V. Camus's automatic carriage made for 
 Louis XIV. Degennes's mechanical peacock Vaucan- 
 son's duck which ate and digested its food Du Moulin' s 
 automata Baron Kempelen's automaton chess-player 
 Drawing and writing automata Maillardet's conjurer 
 Benefits derived from the passion for automata Examples 
 of wonderful machinery for useful purposes Duncan's 
 tambouring machinery Watt's statue-turning machinery 
 Babbage's calculating machinery . . . .317 
 
 LETTER XII. 
 
 Wonders of chemistry Origin, progress, and objects of alchemy 
 Art of breathing fire Employed by Barchochebas, 
 Eunus, &c. Modern method Art of walking upon burning 
 coals and red-hot iron, and of plunging the hands in melted 
 lead and boiling water Singular property of boiling tar 
 Workmen plunge their hands in melted copper Trial of 
 ordeal by fire Aldini's incombustible dresses Examples 
 of their wonderful power in resisting flame Power of 
 breathing and enduring air of high temperatures Experi- 
 ments made by Sir Joseph Banks, Sir Charles Blagden, 
 and Mr. Chantry 346 
 
 LETTER XIII. 
 
 Spontaneous combustion In the absorption of air by powdered 
 charcoal, and of hydrogen by spongy platinum Dobe- 
 reiner's lamp Spontaneous combustion in the bowels of 
 the earth Burning cliffs Burning soil Combustion with- 
 out flame Spontaneous combustion of human beings 
 Countess Zangari Grace Pett Natural fire temples of 
 the Guebres Spontaneous fires in the Caspian Sea 
 Springs of inflammable gas near Glasgow Natural light- 
 house of Maracaybo New elastic fluids in the cavities of 
 gems Chemical operation going on in their cavities 
 Explosions produced in them by heat Remarkable changes 
 of colour from chemical causes Eifects of the nitrous 
 oxide or paradise gas when breathed Remarkable cases 
 described Conclusion ... . 360 
 
CONTENTS. XV 
 
 ADDITIONAL PHENOMENA OF NATUEAL 
 MAGIC. 
 
 CHAPTER I. 
 
 PAGE 
 
 Optical illusions The Mirage of the desert Belzoni's descrip- 
 tion Quintus Curtius's account Probable cause Apathy 
 of the Arabs and neglect of the example of the patriarchs 
 Prospet of a remedy Optical illusion of Mr. W. G. S. 
 Association of ideas Cause of vividness of such pheno- 
 mena And of dreams over ordinary events Magic lantern 
 improved by photography and the improvements in 
 artificial light, &c. Professor Pepper's ghost The decapi- 
 tated head speaking Floating cherubs The automatic 
 Leotard The high merits of these Polytechnic inventions 
 Herr Frikel's " Masks and Faces "Aurora Borealis 
 Sensitive flames Shadow pantomime .... 393 
 
 CHAPTER II. 
 
 Life and suspended animation, or asphyxia Interment alive 
 Phenomena of the grave Coma, or extraordinarily long 
 sleeps Bears Toads found in rocks Tadpoles : 
 separated vitality Polypes Aimelides, or worms Process 
 of restoring severed parts Suspended and restored anima- 
 tion Rotifera Reproductive powers of animals and plants 
 Divisibility of matter Facts beyond the range of 
 physics Extraordinary divisibility of life New fact in 
 philosophy The philosophers of fixity Superiority of a 
 child's logic A fact of science for Unitarians Conclusion 409 
 
THE BEING AND FACULTIES OF MAN 
 
 IN REFERENCE TO 
 
 NATURAL MAGIC. 
 
 CHAPTEE I. 
 
 Material and immaterial nature of man Body Mind Life 
 Feeling External matter Touch Separation and connection 
 of all these Plato and the soul Electricity Epicurus Bishop 
 Berkeley David Hume Consciousness and matter Conscious- 
 ness and the immaterial Reciprocal contact Mans primary 
 perceptive power Its contact with and knowledge of matter 
 and the immaterial Its proximity to the infinite Cause of the 
 Epicurean error Berkeley's blunder the other way Cause of 
 Hume's error Self-deception in philosophy Fallacy in a 
 
 MAN is a being with two natures, one of which is physical 
 and material, the other immaterial, or metaphysical as it 
 is called, and both are intimately but mysteriously and 
 incomprehensibly united in all that is known of actual 
 and practicable human existence and action. The 
 physical portion of man's being we may examine by the 
 light of science, and perfectly and accurately know ; but 
 the metaphysical or immaterial portions of his being, com- 
 prehending the three widely distinct and separate though 
 co-operating and co-acting departments of MIND, LIFE, 
 and FEELING, are subject to no law of science with which 
 we are acquainted, and are in their elementary composi- 
 
2 BEING AND FACULTIES OF MAN. 
 
 tion entirely beyond the range of scientific or philosophic 
 investigation. It is true that profound and ponderous 
 metaphysical works have been written on departments of 
 this subject ; for the phenomena of mind are not wholly 
 beyond the range of study and contemplation; but it 
 would only vex and annoy the reader of a popular work 
 like the present to pile up before him the heavy specula- 
 tions of that crude department of Philosophy usually 
 called METAPHYSICS comprehensively, and PSYCHOLOGY 
 and ONTOLOGY distinctively, with its special and embarrass- 
 ing nomenclature and definition of terms, and we prefer 
 for every practical purpose here a simpler and a clearer 
 course, and one which the most general reader may follow 
 with immediate ease through language used in its most 
 ordinary acceptation, and the whole signification of which 
 is decided at once by the obvious aim of the context in 
 which it appears. 
 
 Man, then, consists of two natures, divided into four 
 parts : a material Body, an immaterial Life, an immaterial 
 Mind, and immaterial Feeling. Three-fourths of his whole 
 being therefore is metaphysical or immaterial, and only 
 one-fourth, and that the least essential portion of it his 
 body physical or material. To prove that Mind, Life, 
 and Feeling, though co-operating in human existence, are 
 essentially distinct in themselves, it is only necessary to 
 show that they are each capable of distinct and independ- 
 ent existence. Thus, in the vegetable world, we have Life 
 without Mind or Feeling ; among the inferior animals we 
 have Life and Feeling without Mind ; and in man the latter 
 is added to the others. It is of importance, however, to 
 observe, that while Mind may exist without Feeling, neither 
 Mind nor Feeling can exist without Life. On the other 
 hand, Matter may exist without being associated with 
 Life, Mind, or Feeling ; as it is observable that all the 
 chemical or Material elements of the human body may 
 
PLATO AND THE IMMORTALITY OF THE SOUL. 3 
 
 be found in a state of separation from these, and that 
 when Life, Mind, and Feeling are withdrawn from man 
 the whole Material elements of the human body remain ; 
 and it is hence reciprocally inferrible that Life, Mind, and 
 Feeling may all exist in a state of separation from Matter, 
 and that the soul of man, or his whole metaphysical being, 
 may exist apart from his body. It is not intended by this 
 deduction to say anything in favour of Plato's theory of 
 the Immortality of the Soul. Those who conclude that 
 he proved the immortality of the soul rush hastily to an 
 unwarrantable assumption. The immortality of the soul 
 is a conditional and subjective fact of the Divine 
 Will, ascertainable only by revelation of that will ; it is 
 not an inherent power . or quality of the soul itself.* 
 Plato's argument was, that because the soul does exist it 
 must have always existed, and must always continue to 
 exist. But this argument is fallacious by analogy, and 
 utterly inconsistent with human experience ; for on the 
 same principle, and by parity of reasoning, Conscious- 
 ness exists, and it must therefore have existed from all 
 eternity, and must always continue to exist. But notori- 
 ously, in the experience of every man, our consciousness 
 did not exist from all eternity, and within the limits of 
 
 * Plato in one passage appears fully to admit this, but the 
 admission is not easily reconcileable with his other reasoning, which, 
 however, was early found to be unsatisfactory and unconvincing on 
 the subject. Cicero felt it. to be beautiful, but not impressive. The 
 passage in which he makes the admission referred to also goes, 
 unfortunately, too far, and asserts that the Divine intelligence has 
 given the human soul the right of immortality. But Plato does 
 not base this assertion on its only possible foundation a known 
 revelation of the Divine Will, and nowhere shows that he knew of 
 any such revelation, though it has been suggested, but not estab- 
 lished, that he may have got some of his knowledge from the 
 Hebrews. The intrinsic evidence is certainly against this supposi- 
 tion, as his doctrines on the subject of immortality are too Pytha- 
 gorean for any conceivable Hebrew source. 
 
4 BEING AND FACULTIES OF MAN. 
 
 our present experience it does not always continue to 
 exist, for it may be and is frequently in a state of absolute 
 suspension. It is not therefore true, on any principle 
 either of direct or analogous reasoning, that because a thing 
 exists it must have always existed, or must always con- 
 tinue to exist.* The very converse is the rule of human 
 experience, and it is a rule which admits of no demon- 
 strable exception ; for even matter did not always exist to 
 human consciousness : hence the eternal endurance, or in- 
 destructibility of matter is not demonstrable by so limited 
 and finite a being as man. He can no more tell or de- 
 monstrate what shall be after him than he can prove or 
 demonstrate what from all eternity has been before him ; 
 and he is no more warranted in assuming that matter is 
 indestructible, simply because he cannot destroy it, than 
 he would be in assuming that the moon and planets are 
 incombustible because he cannot set them on fire. Man's 
 ordinary and too popular inference, therefore, that matter 
 is indestructible is an impotent conclusion, founded 
 entirely on the assumption that his own small and limited 
 powers are the boundary of all physical possibility and all 
 knowledge, and not on any complete and absolute ac- 
 quaintance with the whole laws and possible conditions of 
 matter. This defective knowledge of man may be proved 
 by facts recently observed which are exceptions to all 
 the chemical laws and conditions of matter with which 
 human science is acquainted : Biela's Comet, a small 
 nucleus comet without a tail which moves round the sun in 
 a short orbit, which it traverses every six years and a half, 
 was in 1846, without any ascertainable cause, observed to 
 divide into two parts, which have since continued in a state 
 
 * Plato's reasoning, even in his own hands, results in the con- 
 clusion, not so much that the human soul is immortal, as that soul 
 must have existed from all eternity ; in other words, there must have 
 been a Living First Cause. 
 
ELECTRICITY, LIFE, AND MATTER. 
 
 of complete separation, demonstrating the fact that there 
 are conditions in which matter may not be possessed either 
 of cohesion or concentric attraction a circumstance which 
 no known law of chemistry or other science can explain ; 
 and yet we are compelled to recognize this fact, on the 
 authority of astronomy, as being quite as authentic as any 
 with which that great science, or any other science, has 
 made us acquainted; and other facts might be cited. 
 All that we can venture, on the basis of human expe- 
 rience, therefore, to say is, that man cannot destroy matter, 
 but that we are not sufficiently acquainted with its laws 
 to assert that it absolutely cannot be destroyed. 
 
 But another and a nearer fact which we must equally 
 believe, though we cannot explain it, is that Life, and Mind, 
 and Feeling are introduced into, contained within, or with- 
 drawn from Matter, such as our material bodies, without 
 changing, increasing, or diminishing the physical character 
 or amount, or adding to or deducting from the bulk or 
 weight of their Matter. How electricity is contained or 
 operates on and within bodies we may acquire some know- 
 ledge of, but electricity is a material element, capable by its 
 application of expanding and contracting bodies, as electro- 
 lysis has shown, while Mind, Life, and Feeling thrill and 
 float along our nerves and tissues, or flush into the wide 
 region of imaginary existence and action by a mysterious 
 power and range of volition to which we have no key a 
 fact before which logic is dumb. Electricity is not Life, 
 however fondly some have sought, in eager haste, to call it 
 so. True, it has wondrous powers. Dead men have been 
 made to move by it their eyes have opened, and the cold 
 and rigid features have changed and varied with a ghastly 
 counterfeit of 'the expressions of life. Nay, the stomach 
 has, under its influence, been made after death in some 
 degree to perform the function of digestion. But no ap- 
 plication of this great agent has ever, even in one instance, 
 
() BEING AND FACULTIES OF MAN. 
 
 restored Life absolutely departed, or arrested in the dead 
 the slow but certain progress of decay. The physical and 
 metaphysical portions of our body, once really separated, 
 cannot be reunited by this or any other physical agency. 
 
 Life, Mind, and Feeling are thus obviously not inherent 
 in electricity, nor in any other Material element of which 
 nature is composed. The question hence has frequently 
 been asked, what can we know of the external world, see- 
 ing that our minds cannot properly know what they are 
 not in actual and tangible contact with ? This question 
 has been much complicated by the controversial mode in 
 which it has been stated and dealt with, and also by the 
 unwarrantable but unchecked assumptions which have 
 from time to time formed, and still in a large measure 
 form, part of the propositions laid down and admitted on 
 both sides by those who canvass such questions. The 
 Greek physicist laid down the proposition, that nothing 
 but matter can touch or be touched ;* and from this apho- 
 rism, too hastily assumed as an axiom on the mere faith 
 of its own plausibility, it was fallaciously inferred that 
 everything must be material. When Bishop Berkeley 
 laid down the counter-proposition that feeling, or the 
 sense of touch, is not an attribute of matter, because, as 
 must be apparent, it nowhere exists inherently or insepa- 
 rably in matter he confronted the previous proposition 
 with an aphorism equally plausible, and, from the reason 
 just given in support of it, more unquestionably axiomatic ; 
 but then, so fallible is human reasoning, and so eager is 
 man to rush at ultimata and premature conclusions, that 
 Berkeley at once felt himself warranted in drawing this 
 inference : As feeling is not material, and as we can know 
 nothing but what we feel or experience, therefore the 
 existence of matter cannot be proved, and we are war- 
 ranted in concluding that there is no such demonstrable 
 
 * This proposition is the basis of the philosophy of Epicurus. 
 
EPICUKUS, BERKELEY, HUME. 7 
 
 thing as Matter. Hume's philosophy was founded on this 
 basis, and was rendered further preposterous and extrava- 
 gant by his plunging at once into the dark, as far as scepti- 
 cism could possibly go, with the wild and spectral inference 
 that : Because the existence of Matter could not be 
 demonstrated, therefore the existence of no Eeality could 
 be demonstrated, and hence there is no such thing as 
 Eeality. Now if human reasoning leads men of intellect 
 to conclusions like these, leaving the disciples of the phy- 
 sicists, on the one hand, with the proposition that there 
 is nothing but Matter as their creed ; and, on the other, 
 arrays the metaphysicians round the counter-proposition, 
 that Matter cannot be demonstrated, and hence there is no 
 such thing as Matter, and the sceptics at the back of these 
 to draw their wild and wide conclusion from both sides 
 of the controversy, and, if they have a mind, state it in 
 a syllogistic negative thus : As nothing but matter can 
 touch or ~be touched, and the existence of matter cannot be 
 demonstrated, there can be no other tangible reality than matter, 
 and the existence of no tangible reality can be demonstrated 
 the result is surely disastrous only to man's intelligence. 
 
 It is melancholy to find men of thought and unquestion- 
 able power contented thus to pervert the great qualities 
 of Godlike intellect, and, in deference to their own pet and 
 favourite theories, leave the grand questions of eternal 
 truth in this state. It is so easy in such directions to 
 reason a little way above the average intellectual energy 
 of mankind, that it becomes just the more deeply and 
 indelibly reprehensible to stir up mere sediment into the 
 fountain of truth, and leave the common mind to grope in 
 the darkness of its muddled and inky waters. And yet 
 such is the condition in which partisan philosophy has 
 left this noble department of inquiry and thought. 
 
 In the preceding summary we have condensed this 
 subject, and stated its substance rather than its detail, that 
 
8 BEING AND FACULTIES OF MAN. 
 
 we might not embarrass the general reader with tediously 
 protracted sophistries, nor foul his free and healthy mind 
 with subordinate and disingenuous controversies intensely 
 unworthy of his attention. Truth is not so dark when 
 candour comes to deal with it as these eubtle and merely 
 technical philosophers would make it ; for the whole truth 
 of their philosophy depends, not upon the facts, but on the 
 accuracy or inaccuracy of the terms or language in which 
 they have expressed themselves ; and it is only necessary 
 to state their propositions in detail to show in how many 
 parts the chain of logic is broken and fragmentary, and 
 the reasoning inconsecutive, because they have assumed 
 their language to be perfect ! 
 
 Let us take then the proposition, ' nothing but matter 
 can touch or be touched,' and, following it, the proposition 
 by which it is so obviously refuted, that ' feeling, or the 
 sense or consciousness of touch, is not material, nor an 
 attribute of matter.' From this latter proposition, which 
 is obviously correct and irrefutable, the next proposition 
 is said to be drawn, that as our feelings or sensations are 
 not material, and as it is from these feelings or sensations 
 that all our knowledge of what is external to us is derived, 
 and we are conscious of nothing but them, therefore we 
 have no knowledge of matter or external nature, and the 
 existence of matter is not, and cannot be demonstrated. 
 This inference is certainly very plausible, but it is not 
 warranted by the antecedent proposition on which it pro- 
 fesses to be based, and without which it has no foundation. 
 An intermediate link of the logical chain has been dropped 
 in arriving at it, and when that link is replaced it will be 
 found fatal to this last over-drawn inference, for it does not 
 bridge the leap between it and its antecedent, but carries the 
 current of deduction and truth off in a totally different direc- 
 tion. While it is quite true that feeling, or the sense or con- 
 sciousness of touch, is not material, nor an attribute of 
 
CONTACT OF MATTEE AND THE IMMATERIAL. 9 
 
 matter, it is not true that feeling, or the sense of touch, as 
 is hastily assumed by the succeeding inference we have 
 stated, does not touch ; for it could not be a sense or con- 
 sciousness of touch, without touching. The missing link in the 
 chain, therefore, is the proposition that the sense of touch 
 does touch, and is a consciousness of touching. It is, in fact, 
 the point of contact between Matter and the Immaterial or 
 Metaphysical, and but for the fact that the sense, or con- 
 sciousness of touch touches the first proposition, that nothing 
 but matter can touch, or be touched, would not be disproved 
 by the other proposition, that feeling, the sense of touch, is 
 not an attribute of matter ; for it is only because the sense 
 of touch touches that we are enabled to demonstrate the 
 inaccuracy of the first proposition, and say that something 
 else than matter can touch or be touched that our con- 
 sciousness of touch, which is not material, can touch Matter, 
 and that Matter can, reciprocally, touch our Consciousness. 
 Hence our consciousness of touch is an actual contact with 
 that which we call Matter, and is a demonstration to us of 
 the existence of that Matter. What then becomes of the 
 wild inference that the existence of Matter cannot be 
 demonstrated ? And what of Hume's wilder and wider 
 leap into the chaos of metaphysical intangibility, that 
 Keality is incapable of demonstration ? 
 
 The result of this correction is that the proposition 
 
 1st. That ' nothing but matter can touch or be touched ' 
 is untrue, for 
 
 2nd. Feeling, the sense or consciousness of touch, is not 
 material, and 
 
 3rd. Feeling, or the sense of touch, touches and is con- 
 sciousness of touching Matter, and, consequently, 
 
 4th. Matter and the immaterial or metaphysical may 
 be, and are, mutually capable of touching, and are in actual 
 contact when the consciousness of touch is occasioned, 
 and 
 
10 BEING AND FACULTIES OF MAN. 
 
 5th. By this positive and actual contact the existence of 
 the physical or material world is, by contact, known and 
 demonstrated to the immaterial and metaphysical. Hence 
 
 The inferences that the existence of Matter and of 
 Reality cannot be demonstrated are reduced to ab- 
 surdity, for 
 
 First. Consciousness, though not material, is a BEALITY 
 and is the great primary perceptive faculty of man. 
 
 Note. As such it claims the primary place in the 
 preceding table occupied by the false proposition, that 
 ' nothing but matter can touch or be touched ;' the re- 
 maining four propositions of the table following it in 
 logical sequence, and demonstrating that, 
 6th. The primary reality of Consciousness is capable of 
 knowing and demonstrating to itself the existence of Matter by 
 touch, as well as its own metaphysical or immaterial existence 
 and reality by its Consciousness of such existence and reality. 
 
 Hence Epicurus, Bishop Berkeley, David Hume, and 
 their respective disciples are all in error, though it must 
 be borne in mind that to Bishop Berkeley is due the 
 honour of refuting the materialists and laying down the 
 second proposition in the preceding table, which forms 
 the groundwork of their refutation; but it is the third 
 proposition of that table, founded on the second, which 
 really contains the refutation expressly of their proposition 
 by demonstrating that something besides matter can touch 
 and be touched, and that consciousness of touch is the actual 
 contact of the physical and metaphysical. 
 
 But now let us consider some further facts connected 
 with Consciousness this great primary perceptive faculty 
 of our being ; for all our physical senses and faculties are 
 mere vehicles and channels of its action, and without it 
 the eye, however perfect, is blind, the ear deaf, the touch, 
 smell and taste all alike powerless and incapable of vital 
 action ; for it is only when our Consciousness is present in 
 
CONSCIOUSNESS AND ITS POWERS. 11 
 
 any of these faculties that they perceive, or are capable of 
 perceiving. While Consciousness, then, is a reality, and is 
 our primary perceptive faculty, the following propositions 
 are true in regard to it, and follow each other as conse- 
 quences and experiences from it. 
 
 1. Each man has only one faculty of Consciousness, and 
 that Consciousness constitutes his primary identity to 
 himself, for in the course of life his body and other points 
 of temporary identity change from childhood to age and 
 lose all the features of literal identification. 
 
 2. This faculty of Consciousness is not capable of doing 
 two things at a time, or receiving two or more simultaneous 
 sensations, but its acts and sensations are successive, one 
 following another : thus when the consciousness of hearing 
 is in action the consciousness of seeing, or anything else, 
 is for the moment suspended. 
 
 3. This faculty of Consciousness, though not forming 
 any part of our bodies, nor inherent in the matter of them, 
 does, while we live in this world, reside for the time being 
 within our bodies and within and in actual contact with 
 the Matter of them, though not within any particular por- 
 tion of our bodies or of their material components ; for, 
 
 4. The faculty of Consciousness is capable of pervading 
 every part of our body in the most rapid succession, changing 
 from head to foot, from hand to hand, from eye to ear, 
 from taste to smell or touch, and from any point of touch 
 to another over the whole surface of our bodies, and all 
 this with such celerity and ease as sometimes to deceive us 
 into the idea that we have received simultaneous instead of 
 merely rapid successive impressions or sensations. 
 
 5. The faculty of Consciousness is therefore, and as 
 they are successively exercised in conjunction with it, in 
 actual contact with the impressions of all our faculties, and 
 can consequently place itself in actual though metaphysical 
 contact with every physical impression which our physical 
 
12 BEIN6 AND FACULTIES OF MAN. 
 
 faculties are capable of receiving or being affected by, as 
 well as with every other kind of impression, not necessarily 
 physical, by which they are affected. Thus, when we 
 indulge the imagination or memory, or when we dream, 
 the physical faculties, engaged for the time in any of these 
 occupations, are impressed or affected by the metaphysical 
 influences of imagination, of memory, or of dreaming, 
 and the amount of Consciousness exerted for the time is in 
 contact with these physical faculties, and, through them, 
 perceives the metaphysical influences by which they are 
 affected ; and hence it follows that, 
 
 6. The metaphysical faculty of Consciousness is capable 
 of actual contact with all the physical faculties of our 
 nature, and with all the other realities, or influences of 
 other realities, whether physical or metaphysical, by which 
 these physical faculties may be impressed or affected. 
 
 7. It follows from the preceding that one metaphysical 
 fact or influence, such as imagination, memory, or dream- 
 ing, may come into contact with another metaphysical 
 fact, our Consciousness, by using a physical and material 
 faculty as its intermediate channel or vehicle of operation 
 in doing so. Thus the physical faculty standing between 
 may be in contact with, and acted upon by, the meta- 
 physical on both sides, and hence we reach the hitherto 
 unapproached conclusion 
 
 8. That other metaphysical powers and influences besides 
 consciousness of touch may come into actual contact with 
 Matter and with material faculties, and positively act 
 upon and impress, and cause action in, the Matter of 
 these faculties just as really as a physical body may 
 penetrate and stir water. 
 
 But may we not go a step further, and, strictly within the 
 limits of logical deduction, place ourselves on the boundary 
 of a greater and a still higher truth, and prove from the 
 following premises, viz. : It is not the eye that sees, but the 
 
CONSCIOUSNESS AND ITS POWERS. 13 
 
 faculty of consciousness when in the eye ; it is not the ear 
 that hears, but only the faculty of consciousness when using 
 the ear ; and so of all our other physical senses it is not 
 they that perceive, but consciousness that perceives by 
 them. But consciousness is not a special organization 
 adapted specifically to seeing or hearing : it is a meta- 
 physical perceptive power, capable of realising in living 
 experience and knowledge any or all of the impressions of 
 our physical faculties, and more it is capable of using 
 these impressions and its knowledge of them as elements 
 of new creations, and new combinations, and climbing the 
 steps of logic and the heights of imagination and memory 
 with them into regions apart from matter, illimitable, and all 
 its own. The eye as an actual faculty, bearing upon the 
 outer world, is to the consciousness nothing more than a 
 mere camera with an image in it portrayed on the retina ; 
 but the retina, without the vital presence of consciousness, 
 is no more capable of seeing the image portrayed upon it 
 than a piece of photographic paper or a plain mirror are 
 capable of seeing because they have images upon them. 
 The retina merely mirrors the image ; it is the Conscious- 
 ness which perceives the image portrayed, and con- 
 sequently, 
 
 9. The same faculty of Consciousness which is capable 
 of perceiving with all its details the illuminated surface of 
 the retina, or mirror of the eye, and the picture upon it, 
 must be equally capable of perceiving the images on any 
 other mirroring surface, or the details of any actual 
 surface whatever, were that faculty of Consciousness equally 
 free to come in contact with such mirroring or other 
 surface, and hence the present factitious, but not inherent 
 limitation of the faculty of Consciousness to our physical 
 and organic nature and its faculties is a restriction rather 
 than a full development of its perceptive powers. And 
 that, 
 
14 BEING AND FACULTIES OF MAN. 
 
 10. Such a fact lands this great primary perceptive 
 faculty of our being fairly and fully on the margin of the 
 infinite, and proves it to be capable of being enabled to 
 perceive all reality, physical or metaphysical, beyond 
 the range of our present experience, were it only allowed 
 to come into competent contact with such reality ? 
 
 It will be observed that the argument here is not for 
 the immortality of the soul, but for its highest powers of 
 perception or knowing, and of acting. The immortality, 
 or durability, of our consciousness is, as we have said, 
 dependent, not on anything inherent in itself; for it did 
 not exist from all eternity ; but on the Great Will and 
 Power by which it was called into existence and continues 
 to exist, and no one can prove what that Will is but by 
 the revelation of it, so that a proof of the immortality of 
 the soul on any other ground is impossible. 
 
 From this point let us omitting the third proposition, 
 p. 9, now stated, and all that follows upon it look back 
 for a moment to the condition of human philosophy dis- 
 played down to the present time by the state of these 
 questions, and what it reveals of man's mental power of 
 self-deception. 
 
 When Epicurus based his philosophy on the aphorism, 
 nothing but matter can touch or be touched, he was 
 guided by one faculty, the eye only, in arriving at the 
 conclusion to which he came ; for had he been guided by 
 the sense of touch itself, in addition, he must have 
 become aware of the fact that FEELING touched as well as 
 MATTER. His blunder, therefore, was that he reasoned 
 from partial and defective premises. Indeed, caustic 
 though the remark may seem, it is more than doubtful 
 whether a blind man would have fallen into the same 
 ditch, for a blind man does not so readily perceive the 
 contact of matter with matter, and is more impressed 
 with the contact of consciousness with matter. Aristotle 
 
CONSCIOUSNESS ,AND ITS POWERS. 15 
 
 and Plato accused the materialists of refusing to believe 
 in anything they could not handle with their hands ; but 
 this is even more than what was true of their philosophy, 
 and less than discriminative in judging it. They 
 evidently did not believe or allow for feeling or con- 
 sciousness in the hand, but falsely assumed that the 
 whole of the hand's function or consciousness of touch 
 was material and apparent, and nothing more than what 
 they saw of the hand with their eyes. But while they 
 saw physical contact with the hand, they never saw 
 feeling or the consciousness of touch in it, and they 
 therefore drew a conclusion as to touch at variance with 
 the sense of touch itself, and with the evidence of every 
 other faculty of man but his eyesight. 
 
 Berkeley, on the other hand, refuted their proposition 
 not absolutely or directly, but only by implication and 
 without really perceiving what was necessary to do it. 
 His proposition that tlie sense of touch is not material 
 implies the refutation, but this element of his proposition 
 he himself expelled from it by gratuitously assuming 
 that the existence of matter could not be demonstrated, 
 and that there was, therefore, nothing for the sense to touch. 
 From want of logical discrimination to state the third 
 proposition (p. 9, ante), he not only did not refute the 
 Epicureans, but left himself without a correct basis for 
 further logical progress, and went off into all the errors 
 of his subsequent fallacious and inconsecutive philosophy. 
 Had he perceived that the sense of touch, though not 
 material, touches is a sense of touch, and must therefore 
 have something to touch before it is sensible of touching 
 he would not only have refuted the Epicureans in direct 
 terms by showing that something besides matter can 
 touch and be touched, but he would also have avoided 
 the blunder that matter is intangible and cannot be 
 demonstrated, and all the errors he, and Hume after him, 
 
16 BEING AND FACULTIES OF MAN. 
 
 crowded on the back of that fallacy. Berkeley confesses 
 to a desire to defeat the materialist philosophy by a 
 'sweeping conclusion against the whole basis of their 
 arguments the existence of matter and he lost his 
 impartiality in the eagerness of his zeal. " Matter," he 
 says, " being once expelled out of Nature drags with it 
 many sceptical notions * * * * without it your Epi- 
 cureans, Hobbists, and the like have not even the shadow of 
 a pretence, but become the most cheap and easy triumph in 
 the world." He fell, therefore, into the weakness and 
 error of seeking to destroy a reality for the purpose of 
 confounding those who perverted it. How little the cause 
 of truth is capable of being so served or promoted is 
 conspicuously illustrated by the fact that the very means 
 employed in achieving his object laid the foundation of 
 just as mucli evil as it sought to cure, and reared up Hume 
 instead of Hobbes, and something more than even absolute 
 Egomism* in the place of Epicurus. For it is painfully 
 evident that, if Bishop Berkeley had not sacrificed his 
 candour to his zeal, he would have made it much more 
 difficult, if not impossible, for David Hume to have been 
 an infidel. 
 
 The power of self-deception, it will be found, from the 
 preceding remarks, is by no means impaired by the study 
 and pursuits of philosophy. Let us hope that candour, 
 and an inflexible love of truth for its own sake, are able 
 to steer clear of those subtle shallows on which theory and 
 speculation have so often foundered and gone to ruin. 
 Many eminently wise men have lived and died without 
 being a whit the more foolish from not knowing much 
 of metaphysics. Is it impossible to believe that these 
 great minds have perceived, altogether outside of meta- 
 physical science, that the great primary perceptive faculty, 
 
 * The denial of everything but one's own existence. Hume 
 denied even the reality of his own existence. 
 
CONSCIOUSNESS AND ITS POWERS. 17 
 
 human consciousness, possessed a power of touch or 
 contact with physical nature, without their finding it 
 necessary, as a step in the logical progress of their 
 intelligence, to lay down that fact among the abstract 
 sequences of dialectics, and that they have not erred 
 the more in all the practice and nobler aims of life from 
 neglecting to do so? Fortunately, practical human life 
 is not conducted under the light of dialectics, but men 
 have to judge very much on the impulse and necessity 
 of the occasion in most things, and were it not for their 
 power to do so few would be able competently to meet 
 the responsibilities of existence. 
 
 It may now form an amusement for such of our readers 
 as care for the exercise of logical analysis to turn back 
 to the syllogism stated at page 7, of the preceding 
 remarks, which contains the whole concentrated force 
 of David Hume's philosophy, and satisfy themselves how 
 much sophistry there may be, after all, even in so solemn 
 a formula as a syllogism, and how utterly false it may be 
 in every member of it ; for in that instance it will be 
 found that the first blunder is a double one in the major 
 proposition. For those who would like to follow the 
 subject of Metaphysics still further, reference is made to 
 the learned and discriminating article, "Metaphysics," 
 in the Encyclopaedia Britannica, and the first dissertation 
 prefixed to that work, which will show what a muddle has 
 hiherto, in all ages, been made of this great department of 
 thought, and in what a disgraceful condition it 'has been 
 left to the present day from want of a little consecutive 
 directness and unbiased simplicity of thought. 
 
 But the primary perceptive power or Consciousness of 
 man, its actual contact with, and knowledge of, Matter and the 
 Immaterial, and its proximity to the Infinite, having been 
 so far indicated, let us now deal with the physical faculties 
 in connection with it, as forming its existing channels of 
 
 o 
 
18 
 
 BEING AND FACULTIES OF MAN. 
 
 operation, and with a few features of their structure and 
 action, which Sir David Brewster has not in his Letters 
 brought forward, but which, in some instances, tend to 
 throw considerable explanatory light on many of the 
 phenomena of Natural Magic he has set forth. 
 
CONSCIOUSNESS AND ITS POWERS. 19 
 
 CHAPTEK II. 
 
 Consciousness as the primary perceptive faculty of our Being Its 
 contact with reality and with all our impressions and sensations 
 of reality Eye and Ear more subject to influence from simulated 
 impressions than the other senses Touch and Taste possess more 
 positive powers and means of accuracy Smell intermediate in 
 point of power Bishop Berkeley and the Eye Not the Eye that 
 requires education from experience, but the Consciousness The Eye 
 perfect from the first Difference between the Consciousness of man 
 and of other animals Difference between instinct and reason 
 The Seat of Sensation Misapprehensions as to it Consciousness 
 moves through our bodies Capable of extension on surfaces* 
 Consciousness of space Action of the senses not necessary to 
 Consciousness in them Power of Consciousness over the faculties 
 Pleasure and Pain Attention Thought Memory. 
 
 IN the preceding chapter let us venture to hope it has 
 been proved to the satisfaction of even the most general 
 reader, who is at all a thinker, that CONSCIOUSNESS, the 
 great primary perceptive power and faculty of our Being, 
 is actually in contact not only with all we know with all 
 the impressions with which external nature or reality 
 affects us hut also with all the channels, senses-, powers, 
 or faculties, material or immaterial, organic or inorganic, 
 with which we are endowed as means of knowing or 
 receiving impressions, real or imaginary, at all times when 
 we are conscious of those impressions : and also that when- 
 ever touch, or actual contact with anything, is necessary 
 to the sensation with which we are impressed by it, our 
 consciousness is present in the act of contact, and, as such, 
 is the only means by which we are aware of that contact, 
 or receive any impression or sensation from ifc. 
 
20 BEING AND FACULTIES OF MAN. 
 
 Whenever we receive impressions without actual contact 
 with the objects or causes which produce them, our con- 
 sciousness comes in contact with the impressions so pro- 
 duced, and not with the objects or causes themselves ; and 
 this applies especially to what is seen and heard by us, 
 for in these cases the impression produced on the eye or 
 the ear is all that our consciousness comes in contact with 
 by seeing or hearing. And as hearing and vision are thus 
 faculties, or powers of perception, which do not come into 
 actual contact with the objects or causes from which 
 their impressions proceed, but only with the impressions 
 proceeding from those objects, it follows that the eye and 
 the ear must be much more subject to influences which 
 simulate their real impressions, and must therefore be 
 more liable to deception than the other senses are. And the 
 experiences detailed by natural magic show this to be 
 strictly true. The senses of taste, touch, and smell, are 
 rarely deceived in comparison with the senses of seeing 
 and hearing, and the means of deceiving the former are 
 much more limited in number than those which may be 
 brought to bear upon the two latter faculties. This will 
 be better understood from the following analytical com- 
 parison of the powers of the various senses. 
 
 Pleasure and pain the agreeable and disagreeable are 
 more or less common sensations of all the faculties ; but 
 two of our senses, Feeling and Taste, involve touch, or 
 actual contact, and the perception of temperature in their 
 exercise. Two others, Sight and Hearing, do not involve 
 touch, or actual contact, neither do they involve as a 
 sensation the perception of temperature. The fifth sense, 
 Smell, occupies an intermediate position between the four 
 others which are thus arranged into two sets, and partakes, 
 and in part does not partake, of the powers of each set ; for 
 the sense of Smell, or the olfactory organization, does not 
 as a rule come into actual contact with the object from 
 
THE SENSES AND THEIK POWERS. 21 
 
 which the sensations by which it is affected proceed, but 
 only comes in contact as a sense with special atoms or 
 particles of what that object emits. This may be said to 
 be partly contact, and partly not. The olfactory organi- 
 zation is also capable of perceiving extreme variations of 
 temperature as a sensation, though it is not very sensitive 
 to the impressions of common temperatures. Extreme 
 heat will consciously affect it, as well as extreme cold ; 
 the latter causing the convulsive action of sneezing in it. 
 It will be thus perceived that the two senses of Feeling 
 and Taste have actual contact and the perception of tempe- 
 rature, and the sense of Smell partial contact and partial 
 perception of temperature, in addition to their respective 
 and distinctive perceptions of feeling, taste, and smell, 
 to protect them from deception, more than the Eye and 
 the Ear, which only see and hear, have. 
 
 Let us now consider the great primary perceptive 
 faculty of Consciousness as it operates through these various 
 Senses as they are called, or, more properly, channels of 
 its action. If the senses be organically perfect in their 
 structure they must operate with perfect accuracy from 
 the first dawn of our experience. Bishop Berkeley, who 
 has been highly complimented by Professor Dugald 
 Stewart on the merits of his work upon the Eye, speaks of 
 the eye being educated by experience. However un- 
 pleasant it may be to damage a literary compliment, truth 
 requires it to be said here that Berkeley is altogether wrong 
 when he so speaks of the eye. That organ is a mere 
 reflecting telescope mounted by nature for us, and is as 
 perfect at the beginning of our existence as it is to the 
 last. The image portrayed on its retina or speculum 
 must, if the optical structure of the eye be organically 
 perfect in childhood, be as accurate in receiving and 
 detailing the first object it is impressed by as any subse- 
 quent object or image. It is not the accuracy of this 
 
22 BEING AND FACULTIES OF MAN. 
 
 image, or its details, that is ever improved by experience 
 in any healthy eye, but it is the great perceptive faculty 
 of Consciousness that improves by experience in its know- 
 ledge and appreciation of the eye's images. It is not 
 therefore the EYE, but the CONSCIOUSNESS, that is educated 
 by experience. A few analogous facts of comparative 
 science will render this very clear. Some animals are 
 endued with perfect sight from their first contact with 
 light. The sight of a chicken is perfect as soon as it 
 chips the shell. But we have no reason to know or believe 
 that the eye of a chicken is more organically matured or 
 perfect at that age than the eye of a new-born child. Its 
 anatomical structure is in nothing that we can perceive 
 more efficient or more complete. The retina in a child is 
 a perfect mirror, and all perfect mirrors give at all times 
 perfect images. But then a chicken's consciousness is 
 given it to perceive and act ; a child's consciousness is 
 given it to perceive and reflect ; and an acting conscious- 
 ness is more easily educated than a reflecting conscious- 
 ness. Hence the difference between instinct and thought. 
 A chicken's perceptions are enough for its guidance. A 
 child is guided by its reflections, and hence its reflections 
 have to be educated and allied to its perceptions, for its 
 guiding power is not in, but separate and apart from 
 its perceptions. A chicken's consciousness is perfect at 
 once within the whole range of its faculties, for its con- 
 sciousness is merely perceptive, and all its faculties are 
 perfect in their impressions. A child's consciousness is 
 reflective, and is not perfect at once, from want of elements 
 of knowledge to enable it to reflect, and it therefore grows 
 by means of knowledge and experience. Hence the 
 superiority, in point of immediate accuracy, of instinct 
 over reason. A chicken will not run into water unless 
 it be of the aquatic species, because it is conscious of 
 danger ; a duckling, though hatched by a hen, will, because 
 
DIFFERENCE BETWEEN REASON AND INSTINCT. 23 
 
 it is conscious of safety. A chicken, or a duckling, will 
 not run into fire, because it is conscious of danger ; a child 
 will, because it is unconscious of danger until it has 
 learned it, not by instinctive perception but by experience. 
 We have not here spoken of animals born blind, for the 
 obvious reason that these cases are not within the analogy 
 we are discussing. In such cases the eye is not perfect 
 or fully matured till it is opened at a period after birth, 
 such as in dogs and kittens. In the latter the develop- 
 ment of the eye's organic maturity is slow, and the full 
 opening of the visual faculty gradual ; but children are 
 not born blind, and we are aware of no gradual maturing 
 of their visual organs after birth as in the case of kittens. 
 Berkeley alludes to the fact that a human being suddenly 
 endowed with sight would not be immediately able to see, 
 but would require experience to enable him to use the 
 faculty ; and the assertion is apt to be employed against 
 the evidence of miracles and their possibility, though that 
 would be contrary to Berkeley's intention in making the 
 remark. To prevent this abuse of it, and also to correct 
 the remark itself to some extent, we have only to ask 
 what is to prevent a man from being instantaneously 
 endowed with the power of perfect sight, just as much as 
 a chicken, by the same source from which both derive 
 vision? Nothing therefore can be founded on this 
 remark of Berkeley's against our Saviour and his apostles 
 giving instantaneously miraculous sight to the blind. It 
 is not at conflict even with experienced natural analogy. 
 
 We have now shown, let us trust, that it is the CONSCIOUS- 
 NESS, and not the PHYSICAL SENSE of man, that requires to be 
 educated by experience. It is of some importance there- 
 fore that we should endeavour to know as much as possible 
 of this great primary faculty and ultimate perceptive 
 power, Consciousness how it operates in conjunction 
 with the physical faculties, and where it resides in our 
 
21 BEING AND FACULTIES OF MAN. 
 
 being, because a good deal of language with which we 
 have become familiar from childhood is apt to give false 
 impressions on this subject. Thus we hear frequently of 
 the SEAT OF SENSATION, and we would naturally like to 
 know precisely what it means. An idea has been created 
 by the use of this expression that our Consciousness resides 
 fixedly at some great centre of our physical organization, 
 toward which all our nerves tend, and where they enter 
 into subtle combination, forming a cumulative basis for 
 its highest powers of comparative perception and action. 
 But this must not be taken as an implicitly concluded 
 axiom because a certain amount of countenance is given 
 to it by our anatomical structure. It is true there are 
 nervous regions and nervous centres of our physical being, 
 but it is not necessarily true that these are the only Seats 
 of Sensation, or that Consciousness fixedly resides there. 
 It appears much more probable to our experience, and 
 judging from it, that when the sense of touch is exercised 
 the seat of sensation for the time being is at the point of 
 contact, and that the Consciousness is there also and 
 shares in the contact. In like manner, of seeing, the seat 
 of sensation is in the eye ; of hearing, in the ear ; of taste 
 and smell, in the organs of taste and smell ; and that the 
 Consciousness does not reside fixedly anywhere, but travels 
 from one sense and one point of touch to another along 
 the nerves, and that a nervous centre is necessary only to 
 enable it to do so, and to connect all the ways and means of 
 its passage for that purpose. And from hence it would 
 follow that Sensation does not travel along our nerves to 
 any seat or centre of Sensation, as has been supposed, but 
 that our Consciousness travels along our nerves in passing 
 from one point of perception or impression to another, 
 and that this is the reason why we are incapable of 
 simultaneous, and only capable of successive impressions. 
 Another peculiarity of our Consciousness is, that it must 
 
TRAVELLING AND EXTENSION OF CONSCIOUSNESS. 25 
 
 be capable not only of travelling along our nerves, but 
 must also be capable of extension upon certain surfaces 
 of them; because in the eye and in the sense of touch, 
 more especially, it is capable of perceiving the extension 
 of length and breadth not as a successive detail merely, 
 but also as a united and present whole in the combination 
 of the many qualities which constitute form. Conscious- 
 ness therefore, whatever it may be, is something more, 
 and of greater dimensions, than a mere point if indeed 
 such a circumscribed amount of surface as a point can be 
 said to exist, for there is no point that we can conceive of 
 so minute that it may not be subdivided for a point, 
 however small, must have a circumference, and that cir- 
 cumference must have a centre with a still smaller cir- 
 cumference ; and there seems no reason to doubt of infini- 
 tesimal divisibility and diminution if we had means and 
 powers sufficiently fine to perceive them. So that, however 
 small the surface of concentrated consciousness of touch 
 may be, it must be something more than a point. But if 
 Consciousness be thus capable of extension on surfaces of 
 our nerves and tissues, why not also on any other physical 
 surface separate from them if free to reach it? It 
 certainly appears to be the fact that when the touch is 
 extended over any such surface the consciousness present 
 in the touch is also extended over and in contact with that 
 surface in the sense of touch. But while these facts 
 appear to justify us in ascribing extension of surface to 
 Consciousness, they do not afford us the slightest means of 
 ascertaining that Consciousness has any definite form. 
 We may be enabled to say that its size or extension of 
 surface is as great at least, and fully commensurate with the 
 size of any surface it is capable of appreciating by actual 
 contact, but that does not enable us to say that Consciousness 
 is of the shape of that surface, or that it is not still larger 
 than that surface, and capable of indefinite expansion. 
 
26 BEING- AND FACULTIES OF MAN. 
 
 It has been said we have but one faculty of Conscious- 
 ness, and that it is capable of only successive, but not 
 of simultaneous sensations. It is not, however, correct 
 to draw this last conclusion quite so far without giving 
 a qualified effect to many considerations bearing on the 
 subject in our experience. Thus, if we lay the open hand 
 down flat on a table or other surface we feel the sense of 
 touch over the general surface of the open hand, but if 
 we raise the hollow of the hand, leaving only the points of 
 the fingers and the part toward the wrist in contact, there 
 will be touch, and consciousness of it, only in two parts of 
 the surface which was generally conscious of touch before, 
 and the sense of touch will be suspended in the inter- 
 mediate portion of the hand. But this division of the 
 sense of touch does not create two faculties of conscious- 
 ness for us, it merely occasions one consciousness of 
 touch in two portions of surface. In like manner our 
 volition is capable of double action : thus we may will to 
 raise both hands and bring them by mutual and simul- 
 taneous motion in contact with any external object or 
 with each other, yet there is but one volition exercised 
 though two members of the body are simultaneously 
 impelled and controlled by it. Indeed, in the experiment 
 with the hand touching a table, just mentioned, it is more 
 strictly true that the Consciousness is extended over the 
 points of contact and also over the part of the hand inter- 
 mediate between them, and that it is only the contact that 
 is suspended in the intermediate part, but not the Conscious- 
 ness, and that this may be looked upon as a case of the 
 extension of Consciousness to and between simultaneous points 
 of contact ; and a more extended illustration of the same 
 thing may be exemplified by the use of both hands in 
 touching an object, in which case the extension of the 
 Consciousness is as great as the distance between the two 
 hands, even to .the extremest point of their possible separa- 
 
CONSCIOUSNESS OF SPACE. 27 
 
 tion from each other. Thus both hands may be used 
 simultaneously to touch an object at two points more than 
 a yard and a half distant from each other upon its surface, 
 and though the intermediate surface of our own bodies be- 
 tween the hands is not in contact with any object, yet Con- 
 sciousness, though without contact, will exist over the whole 
 length of that intermediate portion of our bodies when 
 touch is so exercised. This would seem to show that Con- 
 sciousness may be exerted simultaneously over the whole 
 physical range of our sense of touch, and that, as the whole 
 luminous range of the retina may, by the presence of 
 extended Consciousness, simultaneously see, so the whole 
 physical range of touch may, in like manner, simultaneously 
 feel. But actual contact is not necessary to Consciousness in 
 the faculty of touch. When a blind man raises his two hands 
 before him, and separates them horizontally to a distance 
 greater than the width of his own body without coming in 
 contact with any object, he satisfies himself by Conscious- 
 ness in the faculty of touch, but without any actual touch 
 or contact, that there is sufficient space before him to 
 allow him to advance his body forward without interrup- 
 tion from any object ; and in this case it is by simul- 
 taneous consciousness in both hands, and simultaneous 
 consciousness also of the whole distance between them, 
 that he satisfies himself he may proceed. Actual touch is, 
 therefore, not necessary to Consciousness in the faculty of 
 touch ; and hence Consciousness, that perceptive power of 
 our being by which we become aware -of all things we 
 know, does not absolutely require contact with matter to 
 enable it to discover the existence of reality. It can 
 discover and prove to itself the existence and the reality 
 of space, even though that space were absolutely void of 
 matter. True, it may be said that by extending the 
 hands in space as we have mentioned the blind man uses 
 his hands as a material means of measurement in gauging 
 
28 BEING AND FACULTIES OP MAN. 
 
 space, and tliis qualification is fully admitted. But when 
 the student in a narrow room, with narrow and visible 
 walls of solid matter all around him, shutters closed, and 
 all external light excluded, darts away by an act of 
 thought from the midnight lamp before him, and in one 
 bound of free and outward bursting will contemplates in 
 imagination the remotest cluster of coloured stars that 
 gem the distant sapphire of the night, and plunges into 
 and peoples with his fancy the wide and ever-expanding 
 infinitude beyond them, it is not the real or material that 
 is or ever can be to him a practicable gauge of that vast 
 and traversed region of his mental will, but it is the 
 abstract power of his Consciousness alone, and its inherent 
 contact with and appreciation of the possible its divinely 
 endowed intelligence that makes him aware of space 
 which no physical perception can reveal, and no expanded 
 power of material optics ever measure or exhaustively 
 explore. It is here and in similar instances that he finds 
 his metaphysical powers to be superior in their capacity 
 to all his physical capabilities, and that his Consciousness 
 is shown to be aware of space to a degree far beyond all 
 that mere physics can know or reveal. Another character- 
 istic of man's Consciousness, therefore, is that it is capable 
 of action beyond the range of all known physical agency. 
 
 But as actual contact is not necessary to consciousness 
 in the faculty of touch, so neither is actual seeing neces- 
 sary to consciousness in the eye, actual hearing to con- 
 sciousness in the ear, nor actual taste nor smell necessary 
 to consciousness, or the presence of consciousness, in these 
 organs. Consciousness may be present in any or all of 
 them without their being actually in exercise in a physical 
 sense. Further, Consciousness may excite them into 
 artificial action, and influence them with, and make them the 
 medium of hypothetical and imaginary impressions ; and 
 this fact forms the physical basis for the mental constructive 
 
REASON AND INSTINCT PLEASURE AND PAIN. 29 
 
 power of our being, which may be said to be the dis- 
 tinguishing power of man over other animals. Their 
 greatest power is the power of their faculties and impres- 
 sions over their consciousness, and the physical perfection 
 of these impressions in producing correct instinctive action 
 and choice. Man's greatest power, reversely, is the power 
 of his Consciousness over his faculties, and his means of 
 operating upon them so as not only to perceive correctly 
 what is, but to prove what is not, but is possible or im- 
 possible. But even when our Consciousness uses our 
 physical faculties in the discussion of hypothetical im- 
 pressions, the initiative and directing power is not in the. 
 faculties, but in the Consciousness. So that the will and 
 the power to create and dispose of those hypotheses is not 
 in, or a part of the physical faculties engaged, but is 
 entirely in the Consciousness and its power of volition and 
 abstract perception ; and as this power is generally 
 exercised with an aim which, though distinct and fixed, 
 is not immediately capable of being reached in every 
 instance, this fact proves our Consciousness to be possessed 
 of the power of forecasting, anticipation and predetermination 
 of purpose, which is a power superior to the physical facul- 
 ties or their action. Over many artificial and hypothe- 
 tical impressions with which our physical faculties are 
 capable of being exercised, our Consciousness uses there- 
 fore special and predetermined anticipation as well as 
 supervising selection and control, and the faculties are 
 merely passive under such direction, so that it does not 
 reside in them, but in influences apart from them. 
 
 Let us now consider the impressions of Pleasure and 
 Pain, which are also sensations perceived by our Con- 
 sciousness and not by our physical nature ; for anaesthesia 
 has clearly proved to us that the physical nature may be 
 violated, even to the hazard of life, without producing the 
 slightest sensation of pain, as shown by surgical operations 
 
30 BEING AND FACULTIES OF MAN. 
 
 performed under the influence of anaesthetic agents, 
 by means of which the Consciousness has been rendered 
 dormant for the time. What we call physical pain is, 
 however, produced by injury or violence to the physical 
 system, and is only felt by the Consciousness in connection 
 with the affected part of that system. Yet physical pain 
 is not in the physical system, nor in the injury done to it : 
 neither is it in the Consciousness apart from the physical 
 system. Pain must therefore be an injury done to the 
 Consciousness itself when present in the portion of the 
 physical system which is injured. It has been already 
 stated that Consciousness is present in the sensation of 
 touch, when that sensation is experienced, and is in actual 
 contact in our physical touch with the object touched. 
 Let us suppose that in the act of touching we receive a 
 cut, as in touching accidentally a sharp razor. The part, or 
 rather surface of touch, is here severed. But are we not 
 entitled to say the Consciousness is also partially severed, 
 and that this is what constitutes pain in the Consciousness 
 by a cut ? In like manner, when a burn or scald is ex- 
 perienced by touching, is not the Consciousness present in 
 the touch burnt or scalded, for it is really the Conscious- 
 ness that perceives the pain of cutting, scalding, or 
 burning, where these are felt, and not the physical parts 
 affected, to which we by indiscriminate language usually 
 ascribe the sensation ? When anaesthesia separates the 
 Consciousness from the part to be operated upon, no 
 sensation of pain is felt, though all the physical parts 
 are treated in precisely the same way as if there had been 
 all the Usual sensations of pain attending the operation. 
 And this fact would seem to suggest that if the Conscious- 
 ness were rendered dormant by anaesthesia, when attracted 
 to the extremity of a limb which in that state was ampu- 
 tated, the amputation of the limb, while the Consciousness 
 was in its extremity dormant, might possibly even sever the 
 
PLEASURE AND PAIN. 31 
 
 Consciousness from the rest of the system along with the 
 severed limb, and produce death. Surgeons have ex- 
 perienced unaccountable instances of death under operations 
 which ought not of themselves to have been fatal, and some 
 of these cases this might possibly aid to explain ; and it 
 might admit of being proved by such an experiment as 
 amputating the diseased limb of some inferior animal 
 under anaesthesia, the extremity of the limb being tickled 
 to draw the consciousness of the animal to it while the 
 anaesthetic agent was being applied. The failure of 
 anaesthesia in some instances in securing entire freedom 
 from pain might also admit of some explanation from the 
 fact that the previous pain in the injured part rendered 
 the Consciousness more resident in it, and enabled only 
 dormancy, but not absence of Consciousness, to be pro- 
 duced by the anaesthesia. But while these remarks are 
 by no means insisted in, save as suggesting a line of 
 inquiry, the limits of which, whatever they may be, it is 
 desirable to know, there can be no doubt about the fact 
 that physical pleasure and pain are purely sensations of 
 our Consciousness derived from its contact with the 
 particular arrangements or derangements of our physical 
 nature calculated to excite them, and it shows that the 
 Consciousness abstractly is capable of being both gratified 
 and injured. This is further proved by those sensations 
 of pleasure and pain which are not physical, but purely 
 peculiar to the Consciousness itself, such as sorrow, 
 remorse, regret, fear, anxiety, longing, anger, love, mental 
 joy, hope, confidence or trust, generosity, gratitude, 
 truthfulness, which are attributes, sensations, or capa- 
 bilities of our Consciousness, apart from physical pleasure 
 or pain, and not capable of being ascribed to any physical 
 faculty. For if what we usually call physical pain be 
 not, as we have shown, really physical, nor correctly de- 
 scribed as such, much less are these other sensations 
 
32 
 
 BEING- AND FACULTIES OF MAN. 
 
 physical ; and it would hence follow that separation from 
 the body does not necessarily, and of itself, separate us 
 from the sensations of either pleasure or pain ; for, as will 
 be rendered still more apparent in dealing with the 
 Consciousness in connection with the physical faculties, 
 and their structure and operation, in the succeeding 
 chapter, it will be found that Consciousness possesses in 
 itself alone all the attributes, powers, and sensibilities which 
 we usually ascribe to it only in connection with the present 
 physical arrangement of its existence, and that we are 
 thus enabled to prove the separate capability of the 
 existence, though not of the immortality of the Soul, or of 
 conscious Being. 
 
 But though we have said that Consciousness is capable 
 of extension over the sense of touch, to the degree of 
 perceiving a large amount of surface, and also of perceiving 
 simultaneously different surfaces or parts of a surface, this 
 fact does not essentially qualify what is meant when we 
 say that the Consciousness is capable only of successive 
 and not of simultaneous sensations or impressions. The 
 meaning of this last statement is not that the Conscious- 
 ness may not receive a larger or a smaller amount of 
 simultaneous impressions through any one sense not 
 that we may not, for example, see simultaneously both a 
 horse and his rider, or hear both a trumpet tone and the 
 note of a violin, &c., for either of these instances is but the 
 perception of one sense or faculty but that we cannot 
 direct the Consciousness simultaneously to the impressions 
 of two different senses ; that its attention must be suc- 
 cessively applied where more than one sense or faculty is 
 exercised ; that, in fact, there is but one faculty of Con- 
 sciousness, and but one power of attention in that Con- 
 sciousness. 
 
 This power of attention is also another source of diffi- 
 culty, and we have preferred not to use the expression 
 
ATTENTION THOUGHT. 33 
 
 hitherto on account of the tendency to mislead which is 
 involved in it, preferring the more comprehensive ex- 
 pression Consciousness itself. For though it is difficult to 
 show that attention is only one of the powers of Con- 
 sciousness, and that Consciousness is not always, in our 
 common acceptation, attention because it is certain that 
 Consciousness is never exercised as a faculty or perceptive 
 power without attention being simultaneously and co- 
 extensively exercised upon the same subject on which the 
 Consciousness is engaged we have no means of showing 
 how far Consciousness and attention are identical with 
 and how far they differ from each other. We might, for 
 example, say that attention does not think, it merely per- 
 ceives. But then we might say the same thing of Conscious- 
 ness it merely perceives, but does not think : but this 
 is just another of those plausibilities which, like the 
 Epicurean proposition as to matter and touch, has more 
 the aspect of obviousness in it than the qualities of 
 intrinsic truth ; for Consciousness perceives thought, and 
 attention perceives thought, and these alone, if they be 
 one and the same unitedly if they be twain form the 
 only means by which we do perceive thought. The 
 difficulty hence is to conceive that the only power by 
 which we perceive thought is not our thinking power. 
 We know of no other thinking power we possess but that 
 power by which we perceive thought. The touch, the 
 taste, the smell, sight, or hearing, cannot think, neither 
 can they even perceive thought. Nay, the brain itself 
 cannot think, though it may receive impression and 
 motion under the operation of thinking. All these 
 faculties possess merely the power of mechanical, and 
 some of them also, in a limited degree, of chemical action ; 
 and we know of no other power we possess to which the 
 metaphysical energy of thinking can be ascribed that 
 power of reading the records and impressions of the brain 
 
34 BEINtf AND FACULTIES OF MAN. 
 
 and senses, and of stimulating and controlling their action 
 than the Consciousness and (or ?) Attention. But it must 
 be obvious that the word attention is not commonly used 
 with the full and comprehensive meaning which these 
 facts ascribe to it, and indeed show to be inherent in it ; 
 and that though the word Consciousness is, after all, 
 nothing more than attention, and attention nothing less 
 than Consciousness, when intrinsic analysis and definition 
 are attempted, the expression Consciousness, in common 
 and conventional acceptation, carries more of the meaning 
 we seek to convey than the word Attention would do. 
 
 The power of memory is perhaps one of the most 
 difficult mental qualities under the control of our Con- 
 sciousness for the metaphysician to comprehend. Memory 
 may be said to be the store of all our education and ex- 
 perience, but how or where is it preserved, and in what 
 manner does it write down the records of life, so that the 
 garrulous octogenarian, dead to the present, and incapable 
 of identifying the most familiar features of friendship 
 and kindred around him, wanders back with a vivid 
 delight to the long-departed and forgotten regions of the 
 past, and blends in his narrative old age the reality of 
 his second childhood with the phantoms of the first? 
 Does the Consciousness treasure recollections by some 
 abstract metaphysical power, which at last so peoples it 
 with visions that the view of reality is excluded by the 
 thickly -crowded strata of memory's spectral years ? Or 
 does some dusty volumo of the physical cerebrum, long 
 crowded over and hidden beneath the cares of life, reopen 
 its parchment pages when the over-tension has been at 
 length snapt, and the superincumbent pressure removed ? 
 And if so, in what hieroglyphic caligraphy are its pages 
 panned, that they are thus enabled so intensely to flit in mimic 
 life before us ? It is a strange region of Natural Magic, 
 that wild jumble of the living and the dead ; and yet it is 
 
MEMOBY. 35 
 
 from the nearer margin of this same phantom -peopled 
 region that we have to take the quickening elements for 
 hourly thought and daily action the elements of all that 
 speculation, fancy, or purpose would achieve. Is it then 
 physical, or partially physical, or wholly metaphysical 
 in its character ? Are the senses, or the brain, or any 
 portion of the physical organization impressed with the 
 images or the facts to which memory enables the Con- 
 sciousness to recur ? If the senses were so impressed, it 
 is difficult to conceive that these permanent impressions 
 upon them would not impede their further action and 
 obstruct their power to receive the ever-new and succeed- 
 ing impressions to which we find them open. If the 
 brain were permantly impressed, it is equally difficult to 
 understand how the thought, or memory, should continue 
 to be, as we find it, a volition, and how it could avoid 
 becoming a fixity and a necessity as the region of the 
 past. But the images of memory do not possess the 
 character of retained or perpetuated physical impressions ; 
 they are too deficient in the exactness of their printing, too 
 wanting in the uniformity of stereotype in their repro- 
 duction by the Consciousness for that. They do not 
 always read the same way, and the aspect of a recollected 
 image or event is never quite or exactly the same. It has 
 a conjured-up and shadowy aspect, which is tremulous, 
 shifting, and uncertain in the light of thought, so that 
 even the spectra of a dream are more vivid and distinct 
 than the imagery of a recollection. And from this we 
 are led to infer that, as the figures seen in a dream are not 
 real impressions on the eye, but fictions which simulate 
 reality, so in a much less degree are recollections the 
 results of retained and permanent physical impressions, 
 otherwise their imagery would be at least as distinct, if 
 not more vivid than the fictitious visions of sleep. 
 Everything rather tends to show that the Consciousness. 
 
36 BEING AND FACULTIES OF MAN. 
 
 as a metaphysical essence of reality, is capable of being 
 permanently impressed by its perceptions, just as, in dis- 
 tinguishing between instinct and reason, we have shown 
 that it is capable cf being educated to the use of the 
 physical faculties. 
 
 NOTE. From what is remarked subsequently at p. 42 in the next 
 Chapter, it will be still more apparent that when images are physi- 
 cally impressed they present a different appearance and excite very 
 different sensations. 
 
THE SENSES. 37 
 
 CHAPTER III. 
 
 Tlie senses the physical media of the Consciousness Tlie evidence of 
 the senses of touch and taste Its impartiality Its posit iveness 
 Evidence of the eye and ear comparative and relative Co- 
 operation of the senses without collusion Distinctive perception* 
 or impressions of the senses The current of ideas How stimu- 
 latedIts importance Our relative perception of hardness, size, 
 weight, colour, pitch of sound, &c.0ur positive perception of 
 form Standards of comparison Size differently seen by different 
 individuals Erect vision and the inversion of images on the 
 retina Neither the true size nor true position of objects presented 
 to us by the eye Accuracy of the eye Its superiority over photo- 
 graphyA defect of photography How caused Further re- 
 marks on comparison Mirrors and mode of vision. 
 
 WITH regard to the application of Consciousness to the 
 faculties in their structure and operation, it will be 
 apparent, after what has been already said, that it is our 
 Consciousness which possesses all the powers of feeling, 
 seeing, hearing, tasting, and smelling ; that the touch, 
 organs of taste and smell, eye and ear, are only the places 
 where and mechanical channels or physical media by 
 which it perceives these sensations ; and that it possesses, 
 in addition to these powers of perception, sensibilities 
 which no physical matter, however applied or organized, is, 
 or by any known law of nature can be, indued with, as an 
 inherent and material attribute of, or coexisting identity 
 with, matter. 
 
 Let us now consider the structure and action of the 
 physical senses themselves, for we must still call them by 
 that name though strictly they are only physical channels 
 
38 BEING AND FACULTIES OF MAN. 
 
 of Consciousness, and are not senses in any meaning by 
 which sense or physical consciousness of the impressions 
 upon them is implied. Now a little attention to the 
 distinctive peculiarities of the five senses will make us 
 aware that, instead of any ground having ever existed for 
 Berkeley's theory of the non-demonstrability of matter, the 
 experience of the various senses is so distinguished and 
 arranged as to give us every kind of evidence necessary to 
 demonstrate the existence and all the externally obvious 
 and immediately appreciable peculiarities of matter. 
 Thus touch is necessary and able to perceive the actuality 
 of matter as well as whether it be soft or hard, and what 
 is its general temperature as compared with that of the 
 sense of touch itself whether or not it be warmer or 
 colder than the sense of touch. Taste is able also to 
 perceive the actuality of matter, for it, too, is touch, though 
 of a different kind ; and the Consciousness has thus the 
 testimony of two distinct and separate witnesses for the 
 actuality of matter, and two witnesses between which 
 there can be no collusion ; for they cannot, even if they 
 would, give the same testimony. Their evidence is 
 distinct, separate, and different in character, and its only 
 point of agreement is, not one of identity, but of corrobora- 
 tion. Taste cannot give the evidence of touch, nor touch 
 the evidence of taste ; but Consciousness is equally im- 
 pressed with them both. Taste discovers to our Con- 
 sciousness, not merely by actual contact like touch, that 
 matter is and has temperature, but also whether it has 
 certain immediately excitable chemical actions, or chemical 
 qualities, in addition to those which touch is capable of 
 perceiving. It is, in fact, a more sensitively endowed and 
 discriminating kind of touch, and exactly that more acute 
 and skilful sort of witness we should wish to test a 
 matter of fact further for us, after an ordinary witness, 
 on whom we commonly relied, had first reported and 
 
THE SENSES. 39 
 
 testified of its existence. These two witnesses therefore, 
 Touch and Taste, give evidence to us, by actual contact in 
 which our Consciousness partakes, of external matter, its 
 actuality and certain of its qualities ; and, of these, its 
 temperature more especially. Their perception of this 
 last quality being corroborative evidence, but distinctive 
 while it is so ; for what is warm to the touch may be, 
 and at ordinary temperatures generally is, cold, or not so 
 warm to the taste the taste being warmer than the touch, 
 as we find by applying the hand to the tongue : so that 
 an object which the hand would not melt, or warm by 
 contact with it, the tongue may ; and thus these two senses 
 confirm each other even while they differ, and may be 
 called the positive senses, while the eye and the ear are 
 only capable of being ranked as abstract senses, whose 
 function is not to prove the reality of matter, but, after its 
 reality has been proved by these two other senses, to aid 
 in revealing its comparative relation to other material 
 objects and its points of difference and distinctive iden- 
 tity. Thus neither the eye nor the ear comes into actual 
 contact with objects. The eye perceives only the form 
 and character of surface, and the relative size, position and 
 colour of objects; and all of these but colour the sense of 
 touch can ordinarily corroborate and confirm, or rather 
 positively ascertain for us without the eye, where objects 
 are within reach ; so that colour may be said to be all 
 that the eye distinctively perceives of objects more than 
 the touch. But while the eye perceives many qualities 
 of objects in common with touch, and only colour distinc- 
 tively and by itself, the ear perceives hearing or sound 
 by itself exclusively, but does not perceive anything in 
 common with the other faculties. Yet even in this dis- 
 tinctiveness the ear is not so entirely separated from the 
 corroboration of the other faculties as the eye is in its 
 perception of colour ; for while no other faculty but the 
 
40 BEING AND FACULTIES OF MAN. 
 
 eye can perceive colour or can, undirected by the eye, be 
 consciously employed in producing it, the action of the 
 touch can produce sound, and the eye may guide the 
 action of the touch in its production. So that the hearing 
 may be fully corroborated by the action of the touch 
 under or without the guidance of the eye; while the 
 perception of colour can be corroborated by no separate 
 sense, but rests on the testimony of the eye alone. Under 
 the expression colour it will be readily understood that 
 light in all its varieties of white, blue, yellow, red, and 
 intermediate tints is comprehended. Darkness the eye 
 can hardly be said to perceive, since blind men are conscious 
 of that without eyes : darkness to man being, in strict 
 parlance, absence of optical sensation or impression. 
 
 But it is in the sensations of pleasure and pain that all 
 the faculties are distinctive in the highest degree and 
 most widely separated in their experience and the charac- 
 ter of their perceptions from each other. On a common 
 or average level of ordinary experiences they coincide 
 with and corroborate each other in many particulars, but 
 away from that they each and all widely differ, though 
 their difference is not of the nature of contradiction or 
 disagreement. The sensations of pleasure or pain are in 
 no two senses the same, or even similar, except in the one 
 common quality of being liked or disliked by our Con- 
 sciousness. A painful object to the eye has no analogy 
 to what is painful or disagreeable to the touch, taste, 
 smell, or hearing ; and a pleasant landscape is equally 
 inappreciable by the hand, tongue, nose, or ear. Its reality 
 we may prove by testing some of its details with the 
 other senses, but its beauty, and the pleasure its beauty 
 gives, we can recognise and enjoy only by one. " The eye," 
 but the eye only, " loveth light." The other senses 
 perceive it not. And so the ear, but the ear only, appre- 
 ciates the pleasures of sound or music : the smell only 
 
THE SENSES. 41 
 
 appreciates the pleasures of fragrance : the touch, or 
 Consciousness in it, only the pleasures of warmth or cool- 
 ness: and the taste, only the pleasures of sweetness, 
 pungency, &c. 
 
 All these rest on the bare testimony of each respective 
 sense so completely that, though we may test by the 
 other senses to some degree how these sensations arise, 
 we cannot so prove them as to show that they are necessary 
 consequences of the causes from which they spring, or 
 indeed that they are consequences at all, save to the re- 
 spective senses which alone perceive them to be so. But 
 though thus resting only on the single testimony of each 
 respective sense, these impressions of pleasure or pain 
 so powerfully impress the Consciousness as to bring it 
 vividly into positive contact with them, and therefore 
 enable it, without other evidence, to judge in the most 
 positive manner for itself. Such strong impressions may 
 be said to compel the conviction of our Consciousness 
 by their self-demonstrative power. And while ordinarily 
 our Consciousness controls our faculties, here the strength 
 of the impression in the faculty controls for the moment 
 and commands the full recognition of the Consciousness, 
 just as in cases of sudden start or alarm. Besides, such 
 impressions are so allied to the ordinary, but neither 
 pleasurable nor painful impressions of the same faculties, 
 that they are all capable of proof by relation or analogy. 
 There are many instances, however, in which the Conscious- 
 ness is semi-dormant, or so passive as to be controlled 
 by the faculties. The current of ideas and impressions 
 continually passing through the mind and senses when we 
 are quietly led by, rather than directing the powers 
 of thought, is to a large degree, if not altogether, 
 occasioned by the continuous progress of time and change, 
 and the external actions and influences of reality around us ; 
 and the continual succession of impressions occasioned in 
 
42 BEING AND FACULTIES OF MAN. 
 
 our senses by these is compounded no doubt with previously- 
 formed mental associations, and a strong instinctive and 
 perfectly natural tendency to view and study all things 
 with some reference more or less to ourselves ; just as by 
 our eye we so readily measure every sudden appearance with 
 reference to our personal safety, and always protectively 
 assume danger where there is no time to judge. That this 
 tendency teaches us beneficially to know, and keeps us in 
 a lively present Consciousness of our dependence upon, 
 our connection with, and our obligations to events, can 
 hardly be doubted ; and therefore the fact that the EGO 
 dominates very much throughout these currents of thought 
 is not so reprehensible as we might blushingly be inclined 
 to admit were our day-dreams open to the contemplation 
 of other eyes. While therefore the illusions sometimes pro- 
 duced upon the senses such as Sir Walter Scott describes 
 in his " Demonology and Witchcraft " (Letter I., the " case 
 of an eminent Scottish lawyer, deceased "), and that re- 
 ferred to by Sir David Brewster in the present Work 
 (Letter III., " Spectral illusions, recent and interesting 
 case of Mrs. A.," and which Sir David has admirably 
 explained by the impressibility of the retina with perma- 
 nent images by overstraining, as exemplified in the case 
 of Sir Isaac Newton and the phantasm of the sun, Letter 
 II.) may be nothing more than the over-intensifying 
 of a power natural to the whole senses as much as to the 
 eye, the phenomena they have described and referred to 
 are scarcely so wonderful as the fact that most of our 
 ordinary human life is passed in a state of fiction, or 
 romance, in connection with the current of our ideas 
 and our day-dreams, while the proportion of our existence 
 which is real and passed in contact with actual events and 
 facts is a mere fragment of our history in comparison. 
 That the imaginings of the current of ideas, and the 
 pictures they present to us, do not intensify them- 
 
THE CURRENT OF IDEAS. 43 
 
 selves more strongly, and render themselves more per- 
 manent impressions of the senses, is due not so much 
 to the want of power in the faculties so to record them, 
 otherwise they never would exist at all, as to the activity 
 of the mind, the rapidity of the current of thought, and 
 its continual change as well as the continuity of external 
 motion around us, by which the Consciousness is being 
 continually attracted, influenced, and supplied with new 
 elements and impulses of thought ; for it is a singular fact 
 that sudden and absolute silence has been known to stop the 
 whole train of ideas, and produce an almost total suspension 
 for the moment of the power to think a fact due 
 doubtless to the circumstance that we are less accustomed 
 to absolute want of sound than to absolute darkness or 
 want of light, and that the continual operation of noises 
 on the ear has a suggestive and stimulating influence on 
 the current of ideas, the total absence of which we are 
 not accustomed to, and cannot all at once dispense with. 
 Our mental activity, therefore, may be said to have the 
 continual custom established, in connection with its 
 normal action, of being influenced and impelled to day- 
 dreaming and picture-making by the most trivial and 
 indirect as well as by the faintest suggestions ; so that 
 it is not at all surprising superstitious minds under 
 cloud of night, and under all the disadvantages of im- 
 perfect vision, should create spectral appearances out of 
 the most unlikely objects, and indulge in mental exaggera- 
 tions of the most improbable appearances ; for superstition 
 disarms the judgment just as much as darkness disarms 
 the eye ; but neither prevents the current of ideas, nor 
 stops, but rather stimulates the suggestive powers to create 
 not more unreal, but only more alarming images with reference 
 to ourselves under the consciousness that we are not so fully 
 protected as in ordinary light. 
 
 But the uncertainty of the senses is further very much 
 
44 BEING AND FACULTIES OF MAN. 
 
 increased under such circumstances by our being deprived 
 of the immediate power of comparison, for comparison is 
 one of the most important and indispensable means of 
 accuracy our nature is possessed of. Indeed, so important 
 is it that we can hardly be said to know anything positively, 
 but only comparatively ; and that even what things we do 
 know positively have all their most important attributes 
 and qualities so dependent on our power to compare and 
 distinguish by difference that these qualities can only be 
 accurately ascertained by us through the medium of 
 comparison. Thus hardness, size, colour, weight, distance, 
 sweetness, acidity, acridity, flavour, temperature, tough- 
 ness, pitch of sound, elasticity, are all comparative 
 qualities of matter only, and not positive qualities ; so that 
 without means of comparison at command we can never 
 ascertain to what degree or extent these qualities are 
 present in matter. Mathematical forms, however, are 
 positive and absolute. Circular, square, triangular, or 
 other forms of surface are not relative to other forms or 
 bodies, or liable to be affected by comparison ; but beyond 
 knowing that an object is, and that it has a particular 
 form, we cannot be said, without calling in the aid of 
 comparison, and the means by which comparison is 
 achieved, to know anything about it. 
 
 Our most common standard of comparison is generally 
 some quality or sense which we carry about with our- 
 selves, unless where men are engaged in some occupation 
 which requires the habitual use of a fixed measure, weight, 
 or other standard on which they acquire the custom of 
 conventionally relying. For example, hardness is 
 ascribed usually to anything not impressible by our sense 
 of touch, and in such a case the strength of our touch is 
 made the standard of hardness ; but were we to go to 
 the Mint and see a sheet of gold rolled out and then 
 punched into sovereigns, or rhodium our hardest, or iridium 
 
RELATIVE PERCEPTION OF SIZE, ETC. 45 
 
 our heaviest known metal, struck into medallions by 
 means of a powerful lever and die, we would conclude 
 that if a pair of human fingers were as strong and as hard 
 as such a lever and its die, we would cease to call these 
 metals hard to such hands. But we cannot make the 
 strength or hardness of our hands an absolute or a general 
 standard, for no two pairs of hands are exactly alike in 
 strength. Therefore we must for general purposes resort 
 to some conventional and generally agreed on standard. 
 If we take metal, the standard will be very little more 
 reliable than the human hand, for no single metal we may 
 adopt can be found of uniform purity and hardness every- 
 where, even with the same tempering and under the same 
 temperature ; so that a fixed standard of hardness is per- 
 haps one of the most difficult of all conventional standards 
 to establish. And after all it would, when fixed, only enable 
 us to say that bodies to which it was applied were so 
 much harder or softer than it, but not that they had an 
 abstract and positive hardness, independent of comparison ; 
 for to some bodies they would still be relatively soft, 
 and to others relatively hard. 
 
 In like manner size is perhaps not seen exactly alike 
 by any two pairs of human eyes, for eyes differ just as 
 much as faces, and that in many particulars too minute 
 to be mentioned here. The retina of a large eye 
 must portray a larger image of objects than the retina of 
 a small eye. For the accuracy of the eye does not depend 
 on its seeing objects as they really are in point of dimen- 
 sions, but only on its seeing them as they appear to be in 
 comparison with each other : so that a small bird whose 
 eye is no larger than a cabbage seed sees the relative sizes 
 of objects to each other, and to any part of its own 
 body under its range of vision, as accurately as an ox 
 whose eye is more than twice the diameter of a man's ; and 
 yet the details in the image of a landscape of thirty miles in 
 
46 BEING AND FACULTIES OF MAN. 
 
 extent portrayed on the retina of the bird could not be 
 distinctly traced by us without the aid of the most power- 
 ful microscope, though all distinctly seen by the bird 
 itself without any such aid ; and the same image on the 
 retina of the ox, though many thousand times larger than 
 that presented to the consciousness of the bird, could not 
 be traced by us in many of its most prominent details with- 
 out having again recourse to optical science. On the retina 
 of the eye of the bird, a railway train passing over twenty 
 miles of distance in the remote horizon of such a land- 
 scape will not describe a line longer than the breadth of a 
 hair, and yet it will be as distinctly and as accurately seen by 
 a bird as by a man, because the relative sizes and distances 
 of all the objects seen will be maintained, though their 
 true dimensions are not given by the eye either of the 
 man or the bird. But this question will be more fully 
 understood by referring also to the subject of erect vision 
 as it is called, or why, notwithstanding the fact that all 
 
 images are inverted on the retina, we nevertheless see 
 them in their proper and erect position. Thus an arrow 
 placed with the point upwards before the eye, ABC, 
 would, as shown in the above figure, be inverted on the 
 retina at c b a, or portrayed with the point downward, 
 because the rays m n o, and indeed all the rays proceed- 
 ing from the arrow between the extremities of it, A C, and 
 proceeding to the convex surface of the eye, x y, would 
 
INVERSION OF IMAGES IN THE EYE. 47 
 
 cross each other, as delineated in the figure, both before 
 and after passing into the eye. 
 
 Yet we are not conscious that the image is inverted, but 
 see it as if it were erect, and the reason for this is that we 
 see the position and direction of objects only relatively to 
 what we see of our own bodies ; and as our bodies, and all 
 portions of our own bodies seen by us, have their images 
 inverted on the retina as well as the images of other 
 objects, the relative appearance and position of our own 
 bodies is in the image maintained by this inversion to the 
 relative appearance and position of other objects, so that 
 when we move our hand from one place to another, as 
 from the point to the feather of the arrow in the figure, 
 our hand would undoubtedly move downward, but its 
 inverted image on the retina would move upward ; so that 
 the hand would not in consequence afford us any means 
 by such a motion of discovering that the image was 
 inverted. In fact, every object external to the surface of 
 the eye, as must be apparent from a study of the 
 figure, is inverted, so that if the edge of the upper eyelid 
 were seen at as, its image would be presented along 
 the lower side of the retina at , and hence we have no 
 standard external to the eye itself by which we can detect 
 inversion as a matter of experience ; for every conceivable 
 standard external to the eye could only be presented to 
 our vision by means of its inverted image in the eye, and 
 hence before it could become visible to us it would have 
 suffered inversion itself as much as any object whose 
 inversion we meant to test by it. The explanation thus 
 given of the inversion of images, and our inability to 
 detect their inversion in our experience, is capable of being 
 proved even to strict mathematical demonstration. It 
 will thus be found on reflection, that neither the true sizes 
 nor the true positions of objects are presented to us by the 
 eye, but only their relative sizes and their relative positions. 
 
48 BEING AND FACULTIES OF MAN. 
 
 But as the relative positions and relative sizes of our hands, 
 feet, or any portions we see of our own bodies, are correctly 
 given along with the sizes and positions of other objects, 
 we are not conscious of any inconvenience from this fact. 
 Another peculiarity of the eye, which has given a good 
 deal of perplexity and discussion to philosophers, is what 
 some have called the " outness " of vision, or that power of 
 sight by which we perceive solidness in objects and per- 
 spective in space. Some have endeavoured to maintain 
 that the retina was so constructed as to allow images to 
 penetrate its surface to some extent, and therefore show 
 one part of an object a little further back than another. 
 But this explanation is absurd ; for a common mirror or 
 polished metallic surface gives the perspective of images 
 portrayed or reflected on it as correctly as the retina of 
 the eye does, and more correctly than is yet done by 
 photography, for a reason which will presently be ex- 
 plained. And the true solution of the difficulty as to 
 what is called outness of vision is really that images are 
 just as correctly portrayed on the retina of the eye as 
 they are on any ordinary mirroring surface, and that it is 
 not the retina that perceives the perspective so given, but 
 our Consciousness in contact with the surface of the retina, 
 as already mentioned. But as has just been said, a 
 common mirror, and the retina of the eye as well, will 
 give the images and the perspective of objects more 
 correctly than the photographic process yet does ; and 
 the reason for this fact is that in photography a certain 
 amount of distortion and contraction takes place from the 
 circumference to the centre of the image in consequence 
 of the sensitized plate of the photographer being not a 
 concave mirror, like the retina, but a flat surface. This 
 will be in part, but not wholly understood, by re- 
 ferring again to the figure, p. 46, ante, and observing 
 what would be the effect if the retina, instead of being 
 
A DEFECT OF PHOTOGRAPHY. 49 
 
 concave, as there shown, were represented by a straight 
 line from c to a. The result would evidently be that the 
 image of the arrow upon it would be shortened by the 
 difference between the arc of a circle and the chord of the 
 arc. This arrangement of the eye, as compared with that 
 of the photographer who is necessarily, for printing, repro- 
 ducing, framing, &c., confined to the use of a flat surface 
 is of great importance when it is remembered that visible 
 space is a concave spherical area of which the spectator's 
 point of observation forms the centre, and that the concave 
 retina is obviously an optical adaptation of the eye to this 
 natural fact for reproducing concavely to the beholder all 
 that part of this concave space which admits of being 
 simultaneously comprehended within the limits of correct 
 vision, and for which no flat surface interposed instead of 
 the retina could form an effective substitute, or one by which 
 the consciousness could be so correctly brougb* in contact 
 with the faculty. The difference between the accuracy of 
 an ordinary mirror (omitting horizontal inversion) and a 
 photograph is that, as a spectator advances to or recedes 
 from the mirror, not only do the rays from the entire area 
 imaged converge at different angles to him and in varying 
 (increasing or diminishing) relative distance from each 
 other, but they also proceed from different parts of the 
 mirror's surface at each change of distance all but the 
 one ray in the line of which the observer is moving. A 
 photograph, from the fixity of its parts, can thus obviously 
 be correct only at one point of distance from it as com- 
 pared with a mirror, even assuming it to be absolutely 
 correct there. Indeed, in contemplating both photographs 
 and pictures, the eye by long habit acquires almost 
 insensibly a new power of adjusting itself, but only to 
 a certain extent, so as to enable it to see these objects 
 in relief, such as the stereoscope gives more fully, which 
 owes its most important merits to an adjusted and fixed 
 
50 BEING AND FACULTIES OF MAN. 
 
 point of view. Until this power is acquired all pictures 
 appear perfectly flat surfaces, while mirrored images 
 never do so. But the above will show how very accurate 
 and perfect the eye is, even with all its peculiarities, 
 none of which affects its efficiency or impairs its perfect 
 fidelity and trustworthiness, under real and ordinary 
 circumstances, even though in addition to all these 
 singularities of structure and effect we have no fixed 
 and absolute standard of measurement, lineal, superficial, 
 or solid, to apply or trust to, and are compelled to resort 
 to and adopt conventional ones, such as lineal and square 
 and cubic inches, feet, and yards, &c., or to the relative 
 size of our own hands, or other members, in reference to 
 other objects where these conventional standards are 
 wanting ; the last being a very defective standard indeed, 
 and utterly unsuitable for conventional purposes, on 
 account of the great differences in the size of human 
 hands : so that we may conceive how much inconvenience 
 and uncertainty the ancients were under if they relied on 
 the natural cubit, consisting of the forearm and extended 
 hand, until they had reduced it to an average or fixed 
 limit which excluded variation. With regard to weight, 
 again, we are in exactly the same difficulty as we have 
 just observed with regard to measure. We have no 
 positive and abstract standard of the weight of bodies. 
 Their weight is matter of comparison only, and relative 
 to themselves inter se or to us. What feels heavy to us is 
 the primary standard, but is incapable of being made a 
 conventional one, from the difference between each man's 
 strength and that of his neighbour. And here, again, for 
 general purposes we are compelled to adopt a conventional 
 standard on which all are agreed, such as ounces, pounds, 
 or the cubic foot of water as unity, &c. ; and even these do 
 not afford us a uniformly fixed accuracy, for every kind of 
 weight varies according to its altitude or distance from 
 
STANDARDS OF COMPAEISON. 51 
 
 the earth's centre, and the surface of the earth is not at a 
 uniform distance from its centre ; so that slight fractional 
 variations take place with every trifling change of locality : 
 and the yard measure, in the same way, varies from the 
 standard yard to a fractional degree more or less whenever 
 it is in a temperature different from that agreed upon for the 
 standard yard ; for all bodies contract and expand under the 
 influence of temperature, and temperature itself is equally 
 defective in its certainty and equally dependent on an 
 arranged and conventional standard, such as the various 
 thermometers Fahrenheit's, Centigrade, Wedgwood's, &c. 
 The same thing is equally true of all the other obvious 
 qualities of bodies, as a little reflection will make 
 abundantly plain. Diversity of colour, for example, is 
 found to be relative and subjective to the effect of those 
 complementary colours on each other which when com- 
 bined make white light ; for a faint white light appears 
 green near an intense red light, and blue near an intense 
 yellow light, &c., so that all the qualities of bodies are 
 relative ; form, as we have said, being alone excepted. A 
 square is a square, a triangle a triangle, and a circle a 
 circle, &c., whatever be their size ; for form is not 
 dependent upon size, but on proportion of parts; and this 
 is the only peculiarity or characteristic of bodies which 
 the eye or the touch in their normal health can make us 
 absolutely certain of without calling in the aid of com- 
 parison. 
 
 Bishop Berkeley, in his Work on the Eye, tells us that 
 the situation of an object is determined, only with respect 
 to the objects of the same sense ; in other words, the 
 touch perceives the position of an object with reference 
 only to other objects touched, and the eye perceives the 
 position of an object seen only with reference to the 
 position of other objects seen ; and this is strictly correct 
 when applied to the question of erect vision, and within 
 
52 BEING AND FACULTIES OF MAN. 
 
 the limits in which the Bishop employs the remark. But 
 when it is used as an argument against the possibility of 
 any comparison between the impressions of vision and 
 the impressions of touch, &c., it instantly ceases to be 
 true, for Berkeley has wholly overlooked the fact that it 
 is not the physical faculty, but the Consciousness, that 
 perceives the impressions of touch and vision, and that 
 the Consciousness is capable of comparing all its im- 
 pressions and of testing and verifying them by all the 
 processes of reasoning and all the aids of science ; so that 
 it comes at last, as the result of perfectly correct mental 
 investigation, to perceive that images are inverted in the 
 eye, and yet not inverted to the touch, and that a thing 
 may thus be logically and consistently true in all its par- 
 ticulars which is not apparent to the physical perception 
 or immediate experience. The Consciousness can also 
 test and convince us of the fact, that an object which the 
 hand touches is the same object which the eye sees, and 
 that the points of correspondence between them are not 
 merely few and limited, like a set of coincidences, but 
 are universal in all particulars, and without a single ex- 
 ception. This species of correspondence the Consciousness 
 rightly perceives can amount to nothing short of identity, 
 for nothing but identity is capable of it. 
 
 The Bishop also holds that the perception of distance 
 is an acquired, and not an immediate perception of the 
 eye. But in this particular he has also overlooked the 
 fact that the Consciousness is the real perceptive power. 
 If he had only considered the fact that a common mirror 
 in reflecting objects shows distance and perspective cor- 
 rectly, and that the retina is just such a mirror, and 
 possesses the same reflecting qualities and powers, which 
 are fixed and uniform in their action under unalterable 
 optical laws, and that the retina's impressions therefore 
 xlo not and cannot improve or alter by the effect of educa- 
 
MIBEOKS AND MODES OF VISION. 53 
 
 tion or experience that it acquires no new or improved 
 mode of mirroring by use he could not have fallen into 
 this error. He might have been correct had it been true 
 that the objects presented by a mirror are seen on the flat 
 surface of the mirror, for then a mirrored image would 
 have been a flat picture ; but we do not see reflected 
 images on the surface of the mirror by which they are 
 reflected ; for the eye, or the Consciousness as our per- 
 ceptive power, has no physical contact whatever with that 
 surface. We perceive them only by the incident rays 
 which are reflected or thrown off from the flat surface of 
 the mirror after being intercepted by it. We perceive 
 them, in fact, just as if there had been no mirror whatever, 
 but merely as if the direction of the original rays 
 proceeding from the objects themselves had been changed ; 
 for a mirror does not serve the purpose of flattening and 
 localising a picture of the objects it is said to represent ; 
 it merely alters the direction of the rays from the objects 
 themselves. And the question comes to be one of the 
 very greatest difficulty whether we perceive the images 
 on the retina in any other way whether the Conscious- 
 ness is in actual contact with the concave surface of the 
 retina, or whether the rays of light are reflected from 
 that concave surface to the Consciousness seated to receive 
 them elsewhere. To solve such a question, it must be 
 admitted, is no ordinary labour of thought. We shall 
 endeavour to approach it by divesting it of its inessen- 
 tialities of those associated circumstances which are not 
 elements of the question. The first of these is the point 
 whether the Consciousness is seated in the retina or seated 
 elsewhere. Now it matters not whether it is or is not 
 seated elsewhere, for there can be no doubt, wherever it is 
 situated, that the imaging rays are the means by which it 
 perceives the appearances of objects. It is not the retina 
 which Consciousness perceives, but the imaging light, for 
 
54 BEING AND FACULTIES OF MAN. 
 
 these, and not the retina, convey the images. All that the 
 retina can do as a mirror is merely to intercept and change 
 the direction of these rays, and it matters nothing, there- 
 fore, whether the Consciousness receives these rays at the 
 surface of the retina or intercepts them elsewhere these 
 rays are what it receives. Berkeley has said that we 
 do not see by geometrical lines, and that our idea of 
 distance cannot be derived from the angularity of these 
 lines, and he has been pleased to treat this proposition 
 with some little ridicule. But that we do not see by 
 geometrical lines is a statement easier to make than to 
 establish. If, as has been just shown, the Consciousness 
 perceives all objects by means of rays proceeding from 
 them, and impinged upon it at the surface of the retina 
 or elsewhere, it is perfectly certain that these rays pro- 
 ceed from the objects in geometrical lines, and that the 
 angularity of these lines and the consequent presentation 
 of the images is affected both by the fact of relative size 
 and the fact of relative distance. It may be a question 
 whether the Consciousness in contact with these rays is 
 extended as a mere surface to receive them at their point 
 of impact, or has depth as well as surface through which 
 the rays angularly penetrate and so aid it in perceiving 
 geometrically : but this question is beyond investigation. 
 What is much more relevant and certain is that the edu- 
 cated eye does perceive geometrical relation in the posi- 
 tion of objects, and that it does so not because the eye, 
 as the effect of education, has acquired any new or improved 
 mode of receiving images or radiation, but merely because 
 the Consciousness has become more capable of appreciating 
 the images received. It must be borne in mind that 
 vision is accomplished from first to last in human beings 
 only in one way, namely, by radiation impinging on our 
 Consciousness with the velocity of light, and therefore in 
 a continuous stream of luminous motion affecting our Con- 
 
MIRRORS AND MODES OP VISION. 55 
 
 sciousness, and not by the contemplation of a fixed picture 
 in a state of rest. The only fixed appearance involved in 
 the exercise of vision is the real object itself from which 
 the radiation continuously proceeds, and that we do not 
 see, but only its radiated image ; so that to human optics 
 the source of sight is not even the object seen, but the original 
 influence of light, which, falling upon objects, and picking 
 up their images by the way, carries those images as an 
 incidence to our Consciousness; for the incident rays of 
 optical science, after all, are not those rays which, reflected 
 from a mirroring surface, form what we otherwise call 
 deflected rays, but those rays of light which, falling on 
 incidental objects in their course, make the limits and 
 peculiarities of these objects their first mirror or imaging 
 surface, and from mirrors purely so called pick up nothing, 
 but merely suffer additional or further and renewed 
 deflection, and bear with them thence, and still un- 
 impaired, the first image they have acquired in their 
 progress from originally pure light. This is probably 
 not the mode in which a disengaged Consciousness, freed 
 from the eye and its optical arrangements, and in actual 
 contact with objects, would perceive them not the way 
 in which a spirit, or in which God perceives objects. It 
 is, in fact, a limited mode of perception perfectly accurate 
 in all likelihood within its limits, but only showing us 
 how objects appear under applied and special light, not 
 how they appear in their own reality independent of 
 light, or to the vision of Him to whom the light and 
 the darkness are both alike. How absolutely imperative 
 therefore does it become for us in presence of such a fact 
 to subordinate our rash judgments to the wisdom of Him 
 who is perfect in knowledge, and who judgeth not after 
 the seeing of the Eye, but judgeth righteous judgment ! 
 
56 BEING AND FACULTIES OF MAN. 
 
 CHAPTER IV. 
 
 The limited range of our positive or absolute knowledge of external 
 matter How much our knowledge is merely comparative How 
 necessary, therefore, that we should test everything where we can 
 Difference in the mode in which truth and falsehood demand our 
 credence Spiritualism and its stances Its profanation of the 
 dead Table-turning Faraday's exposure of it Simple applica- 
 tion of his indicator for the detection of unconscious lateral 
 pressure and of confederacy Mesmerism Its more preposterous 
 pretensions abated Our tendency to neglect the true knowledge of 
 what is familiar Our ignorance of why or how our hands 
 instantly obey our will Consciousness can control and direct the 
 operations of matter Is it the force by which motion is accom- 
 plished 1 ? Probability that it is not The vital forces and the 
 forces of motion distinguished The blood the life, a mystery 
 Electricity as a motive force in animals Probability of its being 
 the only motive force Structure of the muscles and electric action 
 on them Ampere's theory of electric currents Telegraphic and 
 electro-mechanical nature of animal motion. 
 
 FROM what has been explained in the preceding chapters, 
 it will now be apparent that there are but two absolute 
 qualities of matter, that is, of bodies external to us, 
 which are positive and capable of instantaneous verifica- 
 tion by the senses, viz., the reality of the matter itself, when 
 within the reach of touch, and the form of matter pre- 
 sented to the eye or the touch. How small a number of 
 bodies this would make realizable to the blind man, how 
 limited an amount of the qualities of those bodies it would 
 present, even to the man who sees, must be very evident. 
 tEow narrow therefore would be our knowledge if we 
 
RANGE OF POSITIVE KNOWLEDGE. 57 
 
 depended on these self-evidencing qualities of bodies 
 only ; for of how few of them would touch and form give 
 a complete or satisfactory description. Yet this is the 
 absolute boundary of man's positive knowledge as to 
 matter. All the other qualities he knows of it are 
 relative, the result of comparison and the perception of 
 difference and distinctiveness. Had we but one body only 
 to handle or look at, of its form and reality we could at 
 once convince ourselves ; but its colour, if it have any, 
 depends on the light under which it is seen or the colours 
 by which it is surrounded, and the fact whether it is 
 qualified to reflect the primary, or only the complementary 
 of the colour or light under which it is seen. Its weight, 
 its size, its temperature, &c., are all equally relative, and 
 only capable of being negatively ascertained. It is not so 
 heavy, so large, or so warm as this, or not so light, so 
 small, or so cold as that object of comparison, is the whole 
 amount of our knowledge in regard to these qualities; 
 but what its absolute weight, size, or temperature is, we 
 cannot tell, for we do not know the absolute weight, size, 
 or temperature of anything ; we merely know that such 
 qualities do exist in things. 
 
 It must hence be obvious that our knowledge of the 
 relative qualities of bodies is much more comprehensive than 
 our knowledge of their positive qualities, and that wherever 
 we are deprived of the opportunity of applying those stand- 
 ards of comparison to objects by which alone their relative 
 qualities can be determined we are helplessly thrown on 
 mere trust and assumption for our knowledge, and com- 
 pletely within the power of Natural Magic or appearances 
 instead of realities and at the mercy of misconception or 
 delusion instead of accuracy. Indeed, so much of our 
 knowledge lies within this region, guarded only by our 
 power of reasoning from analogy, which is a mere 
 intellectual extension of our means of comparison and 
 
58 BEING AND FACULTIES OF MAN. 
 
 relative examination, that we are in no instance justified 
 in neglecting or dispensing with all the practical verifica- 
 tion in our power. We are entitled to assume nothing 
 where we have the power to test or verify, and neglect to 
 do so. And as corroboration forms the great convincing 
 power of the senses, when more than one of them are 
 brought to bear upon a subject, if the subject be what it 
 appears and the want of corroboration is instantly mani- 
 fested where it appears to be what it is not no charlatan 
 or pretender has a right to demand our credence till he 
 has fully satisfied every right and requisite of true evidence, 
 and every means of possible corroboration^ which the demand 
 upon us, if justifiable, ought to allow. No teacher of real or 
 important truth will ever ask our credence on less fair and 
 fully satisfactory terms; for teachers of truth are not 
 anxious that it should stand on a weak, precarious, or 
 inadequate basis ; their desire, above all things, is that it 
 should be clear and convincing in itself, and as immacu- 
 late in appearance as it is in reality. We may make 
 perfectly certain therefore that whatever claims secrecy or 
 the dark, or partial obscurity for any point or detail of its 
 manifestation, is stamped with deception or imposture. Of 
 this class, Spiritualism or Spirit-rapping, together with all 
 the Seances and their accessories, in which it darkly or 
 dimly delights, is deeply and indelibly tainted by the 
 very obscurity in which it is self-arrayed. Its stain is 
 inherent in its associations. It dare not come forward 
 and challenge full investigation in the open light ; and no 
 pretended or even real disinterestedness in the operator 
 can rescue it from the brand of imposture. Truth does 
 not so proclaim itself : it disdains the aid of the charlatan 
 or the aspect of mystery. Its most glorious attribute is 
 that it is self-assertive, self-demonstrative, and that it 
 claims in the modesty of its noble and immaculate integrity 
 to be nothing but what it is. But when a rap professes to 
 
SPIRIT-RAPPING TABLE-TURNING. 59 
 
 be a spirit, we are only led to the conclusion that the 
 operators in connection with this imposture are possessed 
 with the ignorant idea that the souls of the departed have 
 more sound than sense, are little improved by their advent 
 into eternity, and have become only fit to be outrageously 
 insulted before audiences as ignorant as the insulter, and 
 not less profane. Nil nisi bonus mortis seems to be no part 
 of the Spiritualist's motto. In his hands men of sense 
 and virtue are only liable to lose their characters after 
 they have joined the array of the just made perfect, and 
 have no voice of wisdom and propriety left among their 
 unworthy relatives on earth to screen their memories 
 from being made an element of ridicule, misrepresentation, 
 and swindling. The kind of evidence which is required 
 to justify our belief in such a case, is not that a spirit 
 should reveal itself, but that those who assert it has to any 
 extent done so should afford us every means, so far as 
 they are concerned, of making certain that there is no 
 collusion. 
 
 But there are other pretensions which have not claimed 
 concealment or darkness as essential to their success. 
 Of these, Table-turning and Mesmerism are examples. 
 The former has gone down before the light it has invoked, 
 and the latter has greatly receded from its first assertions. 
 Michael Faraday showed that while continued muscular 
 pressure might, from the strain and weariness of the effort, 
 become unconscious of lateral tendency, even f while 
 actually exerting it in a very strong degree, a simple 
 index could make us conscious of the fact, and also enable 
 us to detect confederacy ; and thenceforward gyraceous and 
 peripatetic tables ceased to move. Table-turning is at an 
 end, and its history only affords one of those useful illustra- 
 tions of misconceived phenomena which, when fairly placed 
 under the light of general intelligence, science never fails 
 to explain. A simple application of the principle involved 
 
60 
 
 BEING AND FACULTIES OF MAN. 
 
 in Faraday's index may be made by any one, with two slips 
 of paper; one of them narrow, and a few inches long, being 
 wafered down to the table at right angles to the edge, or 
 to a tangent to that point of the edge F G H at G if the 
 table be round, and the other slip not wafered, but laid 
 down transversely on the first piece. This second paper 
 being about six or eight inches long, and an inch or two 
 broad, so that the fingers of a hand may rest upon it, when 
 pressing the table, thus : 
 
 This simple arrangement is quite enough for ordinary 
 purposes where the table is a polished one, as the first 
 slip of paper A B, wafered to the table at A and B, with 
 the index line I I upon it, will remain fixed, while the 
 paper C D, on which the fingers are to rest in pressing 
 the table, but not on that part of it which is over the 
 other slip A B, will move from right to left if there be 
 lateral pressure in the fingers, and the line E drawn 
 across its centre and connecting the line I I, and oc- 
 cupying the position of the dotted line when the papers 
 are first adjusted, will move to one side or other of the 
 index line I in the direction of the lateral pressure, and 
 so at once prove its existence. 
 
 But Mesmerism, while it has much abated in interest 
 and modified its pretensions, has not been so satisfactorily 
 met by scientific intelligence. A good deal of confederacy 
 and imposture associated with many of its manifestations 
 
MESMERISM. 61 
 
 have been detected and exposed, but the more consistent 
 adherents of Mesmerism have complained, and perhaps not 
 unjustly, that quacks and impostors, for the sake of money- 
 making by sensational exhibitions, have perverted the 
 scientific truths which they maintain, and thereby brought 
 discredit on phenomena which are beyond dispute. It is not 
 the purpose here to investigate whether Mesmerism be true 
 or false. The present writer is too little acquainted with 
 its phenomena to pronounce a judgment one way or other. 
 He has seen some few attempts at Mesmerising, but they 
 must have been exceedingly bungled and blundering 
 attempts indeed if Mesmerism be anything but a stupid 
 hoax. The object of the following remarks is not to 
 investigate Mesmerism, but to consider whether we have 
 not within the limits of human knowledge, and admittedly 
 familiar experience, a set of natural facts far surpassing 
 in their reality all the phenomena which Mesmerism now 
 professes to have successfully manifested, and with some of 
 the peculiarities of which Mesmerists may after all be 
 only floundering in the dark. 
 
 It is one of the disadvantages of the student of nature 
 that life-long familiarity with certain phenomena too often 
 leads him rather to assume them as matter of course than 
 to study them as matter of fact to regard them as too 
 commonplace for investigation, because it is accepted as a 
 conclusion too trite for further iteration that they are 
 exhaustively seen under their familiar aspects, and that 
 man must know and understand fully and to the uttermost 
 that which he is encountering every day. Were man's in- 
 tellectuality equal to his opportunities there would be much 
 probability in this conclusion. And it is only when we 
 are privileged through the eyes and understanding of 
 some rarely endowed intelligence, whose mind has opened 
 up a new page of nature where we had thought all was 
 already known, that we discover the fallacy of our assump- 
 
62 BEING AND FACULTIES OF MAN. 
 
 tion, and find we have hitherto been looking at ihe half calf 
 and gilt edges of the volume only, and that the Book in 
 the running Brook, and the Sermon in the Stone, do not 
 preach or expose their letter-press to every one, but, like 
 sensitive and highly-gifted ministers, pause till the audience 
 is sufficiently reverential and attentive. Much of the very 
 best elements of philosophic truth and wisdom is hid 
 under the aspect of commonplace, and familiarity with 
 facts is not necessarily knowledge. The man who has 
 used his hands from youth to age until they have acquired 
 such a property of easiness in custom that for them to go 
 right has become intuitive, and to use them wrong 
 would involve the necessity of special direction, does not 
 from all this experience of his powers know one bit the 
 more how or why it is that the hand so instantly obeys 
 the Will, or by what sprite-quick and Ariel agency the 
 sympathy between the master and the servant is so full that, 
 ere the pulse beats twice, or even once, the hand has acted 
 the thought or seized what the volition has resolved on, 
 and holds it prisoner to our further purpose. Why or 
 how is it that our motions obey our will ? Has all our 
 life-long familiarity with this fact led us a step nearer to 
 the solution of its modus operandi ? Or has our experience 
 only intensified our stupidity, and schooled us into arro- 
 gant indifference and self-satisfied ignorance ? 
 
 All we have said of the great perceptive power of our 
 being CONSCIOUSNESS, we see no reason to qualify here, 
 but neither do we feel it possible to expand the range 
 of what we have said, or propound an extension of its 
 energies, save in only one direction. Consciousness is 
 not physical, nor possessed of physical powers or agencies. 
 It is an intelligence, not material, nor incapable of 
 separate, existence from matter. But its connection with 
 matter, in addition to its contact with and powers of 
 perceiving it which have been already dealt with, appears 
 
OUR PHYSICAL MOTIONS. 63 
 
 to consist of a further power to control and direct the opera- 
 tions of matter. But this, after all, tells us nothing more 
 than we already know, though perhaps under a different 
 aspect, when we say that we will, and our members obey 
 our will. We ask for further satisfaction than this, and 
 the prominent question occurs : Is Consciousness the 
 force by which the will is carried out and reduced to 
 physical action ? Mankind have hitherto lived and died 
 under the passive assumption that it is ; but a little con- 
 sideration will render this assumption very doubtful at 
 least, if it do not conclusively show that it is not. 
 
 It is true that the Consciousness can direct the physical 
 actions of our body, but it is not true that the body is 
 incapable of physical action after the Consciousness is 
 withdrawn. The living body moves its limbs as our 
 Consciousness directs, but the dead body may be also 
 made to move its limbs ; and all that is deficient in their 
 motions as compared with those of the living body is that 
 the Consciousness and its directing power are not there. 
 Electricity will make the dead move, but it cannot 
 replace the Consciousness or its directing power. Hence 
 the physical force or agency which carried the will into 
 effect may be replaced, but the Will itself cannot. The 
 physical force, therefore, is not the Will or Consciousness ; 
 neither, reciprocally, is the Consciousness or Will the 
 physical force. The Will cannot move a paralyzed limb, 
 but electricity properly applied can. The inference from 
 these facts is inevitable : The physical motions of our 
 bodies are accomplished by the agency of electricity, 
 under the direction of our will, so far as they are voluntary, 
 but independently of our will so far as they are involun- 
 tary. Now, without reference to the electric action of 
 dead bodies, there are voluntary and involuntary actions in 
 the bodies of the living, and they form two large and 
 comprehensive divisions of our physical system. The 
 
64 BEING AND FACULTIES OF MAN. 
 
 heart, tlie stomach, the lungs, the liver, and numerous 
 other departments of our physical system move and 
 operate by involuntary action over which the Will has no 
 direct influence or control. So that Consciousness or 
 Will are not the forces by which these physical operations 
 are performed, and have no presiding power over them. 
 We know but of four departments of human existence 
 the Life, the Mind, the Feeling, and the Material body ; 
 but these operating forces of our physical system are 
 obviously not fruits of either the mind or the feeling. 
 Are they, then, part of the Life ? We have no means of 
 discovering that they are, but we have some reasons for 
 concluding that they are not. The dead stomach has 
 been made to digest under the action of electricity, 
 therefore electricity can to some extent supply the 
 necessary force involved in its action without life. 
 Besides, its action is a physical action, and Life is not 
 physical, nor inherent in, nor an attribute of, physical 
 matter. No doubt life exists in a tree, and controls its 
 vital actions, which are its only actions ; but the force of 
 those actions even in a tree is a physical force, and it is 
 impossible to perceive how Life, which is not a physical 
 element, can be a physical force. Yet it is here that the 
 difficulty presents itself in its profoundest form, and here, 
 if at all, that we are bound, as far as possible, to reason it 
 out. Life is not inherent in vegetation, but if life be 
 withdrawn from any member of the Vegetable World its 
 whole forces are suspended, and their whole motions 
 suppressed. It is not physical, and hence not a physical 
 force ; yet when it is present there is physical force when 
 it is absent there is none. Must our reason here recede 
 before the great mystery of Life, and confess itself power- 
 less ? Electricity will kill a tree, but it will not enable 
 it to perform any of the operations of its vitality. It will 
 not make the roots of a plant digest and absorb pabulum, 
 
OUR PHYSICAL MOTIONS. 65 
 
 and send up suitable elements for bud and blossom and 
 fruit, though it may be, and no doubt is, a subordinate 
 agency in these operations. We must, however, meekly 
 confess we cannot penetrate the mystery of Life. But 
 does this stop the line of inquiry we have pursued so far 
 in all other respects ? We think not. All the actions of 
 a plant are vital actions, and we can neither understand 
 Life, nor that kind of action to which Life is essential. 
 But it is not so of man and other animals. All the 
 actions of a man are not vital actions. His muscular 
 actions may be produced without the presence of Life. 
 They form an extension of action beyond the range of 
 trees and plants, and beyond the limited range therefore 
 of essentially vital actions. Perhaps we shall be able to 
 discover that they are as much mechanical actions as 
 those of the steam-engine and other machinery, and 
 as much accomplished by physical forces and agencies. 
 The motions of a tree or plant are only those hydraulic 
 energies by which its sap is absorbed, analyzed, distributed, 
 and applied in the development of the plant ; and in this 
 respect they are allied to those motions of the blood in 
 animals by which the vital energies are kept in operation, 
 and seem to be restricted exclusively to the processes of 
 growth or development, renovation, and reproduction. 
 In this respect, whether it be disputed that the Scriptures 
 teach science or not, there can Ite no doubt whatever that 
 they put the finger of revelation on a remarkable scientific 
 fact, not hitherto considered so fully as it ought to have 
 been, when they say of animal nature that the blood is the 
 Life thereof. If the sap of a tree be not the life of the tree, 
 its operations are so intimately united and identified with 
 the vital forces and actions of the tree as to be utterly 
 indistinguishable from it by any power of human discri- 
 mination ; and in like manner the operation of the blood 
 in animal nature is utterly indistinguishable from the vital 
 
66 BEING AND FACULTIES OF MAN. 
 
 energies of animal life. Electricity, as we have said, may 
 make the dead body move, and the dead stomach digest ; but 
 it cannot make the blood circulate, or the dead pulse 
 throb. Instead of re-energizing the blood it destroys it. 
 A shock of electricity passed through the blood after death, 
 so far from vivifying, separates that fluid into its three 
 component and subordinate elements the red globular 
 colouring matter, the gummy serum, and the watery 
 serum, and renders it altogether unfit for the purposes 
 of vital circulation. But not so with regard to those 
 motions with which animals are endowed, as distinguished 
 from and in addition to the vital energies they possess in 
 common with vegetable life. These motions may be pro- 
 duced after life has departed from the members, and they 
 are thence, we may warrantably conclude, separate and dis- 
 tinct from what we have considered as the vital actions. 
 If electricity may produce every kind of physical motion 
 but vital action, as we find it can in the dead, are we 
 warranted in concluding that anything in addition to 
 electric agency is required or employed to produce such 
 physical motion in the living? Unless we can charge 
 nature in some department of her operations with super- 
 fluity, we are not entitled to assume superfluity here by 
 the only light of reasoning we have to aid us in our 
 determination of this question the light of analogy. 
 Nature is nowhere chargeable with superfluity that we 
 positively know of, and we are excluded by that fact 
 from gratuitously assuming that she may be chargeable 
 with superfluity here. In the living, as in the dead, 
 physical motion may be produced by electricity, and we 
 are warranted by all analogy of nature in concluding that 
 it is produced by that agency alone the Life and the 
 Consciousness having merely a presiding and directing 
 power over it. But a little study of the anatomical 
 structure of animal bodies will lead very much to the 
 
OUR PHYSICAL MOTIONS. 67 
 
 strengthening of this conclusion, for while electricity may 
 act on inorganic bodies and cause motion, independent of 
 organic structure in them, here it does not so act, but 
 operates in harmony with the organic structure only, and 
 in conformity to the aim of predetermined motive arrange- 
 ments. Applied to a dead muscle it will make that 
 muscle act, not as if it were inorganic matter and had no 
 special structure, but as a muscle should act, and in har- 
 mony and strict subordination to its organic structure and 
 purpose ; and this it can only do because the structure of 
 the muscle is such as to allow the operation by it of some 
 electric law of motion, which, if it be not specially and 
 exclusively designed to facilitate, it at all events fully and 
 perfectly coincides with. On this point we feel fully 
 entitled to say that if such perfect adaptation of muscular 
 organization to electric laws be not the result of prede- 
 termined purpose in the arrangement of nature, it is a 
 solecism unparalleled by all mere blind coincidence. But 
 let us now see whether we can detect the electric law 
 from the organization and motion of the muscle ; for its 
 anatomy has been fully ascertained. The electric law, 
 we have said, operates in strict conformity with the 
 muscular structure ; ergo, as matter of induction, the mus- 
 cular action under electricity is the electric action, or iden- 
 tical with it, and must therefore involve the operation of 
 the electric law. Now a muscle consists of a large 
 number of very fine fibres arranged together, terminating 
 at each end in a tendon, and these two terminal tendons 
 respectively form the tendinous origin and tendinous 
 insertion of the muscle ; and muscles are so constructed 
 that they contract or shorten, and extend or lengthen, as 
 may be required when under action. In contracting, the 
 belly of the muscle, or that part of it between the two 
 terminal tendons, swells out. In extending, the belly of 
 the muscle collapses. This is the mode or form of mus- 
 
68 BEING AND FACULTIES OF MAN. 
 
 cular motion ; and having satisfied ourselves of this much 
 it is now our duty to investigate what known law of 
 electricity such a motion coincides with. This, in the 
 advanced state of electric science, is fortunately not diffi- 
 cult to find. M. Ampere's theory of electric currents 
 supplies us with the fact that two parallel, or nearly 
 parallel, currents of electricity, when proceeding in the 
 same direction, attract each other, and when proceeding 
 in opposite directions, or counter to each other, they repel 
 each other. We have only therefore to suppose that when 
 the electricity passes along the fibres of the muscle in the 
 same direction they attract each other, and the belly of 
 the muscle collapses, the muscle being extended; and 
 that when the currents of electricity proceed in opposite 
 directions, that is, so many of them along one set of the 
 muscular fibres from one end of the muscle the tendinous 
 origin, for example and so many more of them proceed 
 from the opposite end of the muscle, or the tendinous 
 insertion, these currents passing each other through the 
 belly of the muscle repel each other and swell the belly, 
 thereby causing the muscle to contract. The immense 
 number of fibres in a powerful muscle, and the number of 
 electric currents thus passing along them, will readily 
 account for the great strength and literally electric 
 rapidity of muscular action ; and we know of no other 
 explanation which furnishes the faintest indication of an 
 adequate cause for this familiar, but not the less remark- 
 able phenomenon. If there be any other force which can 
 produce this action, mankind, as yet, know nothing of it. 
 We do know that electricity can, and does cause it, and we 
 also know that the above is the only law of electricity 
 man has been able to discover by which it can be done in 
 harmony with muscular organization, and that it is a law 
 adequate to the result. We also know that it is by pass- 
 ing through the muscle that electricity causes muscular 
 
OUR PHYSICAL MOTIONS. 69 
 
 action, and that the muscular fibres are conductors ; so that 
 our conclusion amounts, we may almost say, to as com- 
 plete demonstration as the subtle nature of electricity 
 allows. In fact, our nerves and muscles seem to be a 
 series of telegraphic wires and electric mechanism com- 
 bined, by which our volition has accomplished its pur- 
 poses in our physical nature ever since the creation of 
 animal life, and that, great and marvellous as modern 
 electric and telegraphic discoveries are, they are after all 
 only a lucky stumble upon an old law, and an unconscious 
 imitation of an old application of it, as commonplace as 
 humanity and as hoary as antiquity itself. 
 
 We also know from Ampere's theory that currents of 
 electricity influence each other, so that of two transverse 
 currents the stronger controls the weaker, and are there- 
 fore prepared to find that where the distance between 
 them is not sufficiently great, or the insulation not 
 perfect, singular and marked effects might be produced 
 from their proximity. And all this suggests to us that 
 the normal and strictly legitimate electric action of 
 animal bodies is far more extensive, and far more wonder- 
 ful and powerful in the most familiar and ordinary results 
 of animal motion, than anything Mesmerism and Animal 
 Magnetism have been able to establish. Indeed, we are 
 led to conclude that, if there be any grain of truth in the 
 pretensions which Mesmerism has made, it is only a dimly 
 and feebly perceived fragment of this great and common 
 law of animal life on which it has alighted, and which it 
 cannot fully explain. And if so, it is well to observe that 
 its experiments, unless conducted under the light of 
 science, may in many instances be injurious and exhaust- 
 ing to the parties operated on, in consequence of their not 
 being conducted in strict deference to the normal laws 
 of animal action ; and that they ought to be discouraged 
 in all but adequately enlightened and prudent hands ; for 
 everything done in the way of experiment on man ought 
 
70 BEING AND FACULTIES OF MAN. 
 
 to be in a direction tending to promote arid invigorate 
 healthy and natural action only. 
 
 We are now in a condition to contemplate with some 
 degree of wonder that most astcnishing of all the pheno- 
 mena of natural magic that fearfully and wonderfully 
 made compound of immortality and evanescence that 
 " paragon of animals," Man ! To contemplate, too, after 
 more than four thousand years of recorded fact and phi- 
 losophy, how much and how very little we know of ourselves. 
 Familiar in daily life with those who are continually setting 
 up their arrogant and hasty opinions as the finality of 
 knowledge, though they have never exhibited intellectual 
 energy enough to penetrate or discover a fraction of what 
 such a work as this has recorded, or to know how much 
 and how long philosophy has laboured for so little, the 
 conclusion of the Preacher seems to hover like an abiding 
 epitaph over the achievements of man's boasted wisdom 
 in the sighing and disappointed trisyllable Vanity ! 
 
 How small a portion of the great eternal whole is 
 man's present existence, and yet of how many varied and 
 wonderful combinations is it made up ! A physical 
 system which possesses powers of assimilating food and 
 matter, both by analysis and synthesis, which no labora- 
 tory can equal, no skill in science compare with a 
 system whose arrangements eclipse telegraphy by the 
 rapidity and completeness with which they communicate 
 from Will to Act, from sense to sense, intelligence and 
 mandate whose electro-mechanical motive power no 
 machinery of human invention has yet been able to 
 approach a system of pneumatic, hydrostatic, optic, 
 and acoustic combination, each finer in its parts and more 
 perfect in its action than ingenuity can even hope ever 
 fully to understand and added to all these, Life, and 
 Mind, and Feeling forming a metaphysical co-operation, of 
 which we can only say IT is, and then sink our vaunted 
 knowledge into lip-sealed and humbled ignorance. 
 
OUR PHYSICAL MOTIONS. 71 
 
 CHAPTER V. 
 
 Animal motion Spontaneous, involuntary and diseased motions 
 Capable of being artificially produced Defects in Mesmerism 
 Want of uniformity in its results Electro-biology and Phrenology 
 The brain Propensities Cerebral development no proof of 
 propensity Alleged propensity not consistently shown in expe- 
 rience Propensity not material but metaphysical, and cannot be 
 indicated by size and quantity of matter Exercise causes de- 
 velopment Small mental power capable of great achievements 
 Accountability of human life Right and wrong divide the uni- 
 verse Danger of error Tendencies of the age Opinion Differ- 
 ence between Opinion and Conviction Not necessary to form 
 opinion as a basis of action Opinion not truth An impediment 
 to correct action An illustration of this Case of an African 
 traveller Confusion as to opinion Our means of protection 
 against error. 
 
 HAVING so far considered in the preceding chapter the 
 laws and forces engaged in the production of animal 
 motion, and which appear to result in showing that 
 physical action in animals is accomplished by what may 
 be called strictly electro-mechanical appliances, let us 
 now devote some attention to those animal motions in 
 connection with the Will and the Consciousness, and also 
 to a few of the phenomena of spontaneous, involuntary, 
 diseased and artificially-produced motions. 
 
 It appears then, from many well-established experiences, 
 that the Consciousness may be to a large extent separated 
 from physical motions which ordinarily never take place 
 save under its immediate direction and control, and also 
 that a large number of diseased motions are possible over 
 
72 BEING AND FACULTIES OF MAN. 
 
 which the Will and the Consciousness never have any 
 control. Thus the motions of the somnambulist are to a 
 large extent performed without the Consciousness, though 
 they are of a nature over which the Will, in ordinary 
 circumstances, would preside and exercise direction. On 
 the other hand, cramp, lock-jaw, and other diseased actions 
 of the muscles, are of a nature over which, the will un- 
 fortunately never has any control, and they prove to us 
 conclusively that, though Consciousness may be associated 
 with, and part of the vital force, it is not the motive force, 
 nor necessarily associated with it that, in fact, the motive 
 force is not a vital, but merely a mechanical force. 
 
 But all mechanical forces are capable of mechanical 
 regulation and control, and it is therefore quite possible 
 and within the limits of legitimate logic to conceive that 
 what can be produced naturally or by disease in the 
 mechanical motions of the human body may be produced 
 by the application of artificial control over the body. 
 For if motion in a dead body may be produced by the 
 application of electricity, why may not involuntary motion 
 be also produced in a living body by the application of it ? 
 If muscular action be produced by electric currents 
 obeying the volition, why may not more powerful currents, 
 as M. Ampere has shown, be so applied as to control 
 these currents in opposition to the individual will ? If 
 somnambulism and dreaming, and lock-jaw and cramp, 
 may be produced by natural causes, why may they not be 
 produced also by artificial means, if we know how to use 
 these means ? And yet some of these phenomena go far 
 beyond anything that Mesmerists have been able to prove, 
 and show an involuntary mechanical and electric action 
 in our physical nature beyond the Mesmerist's absolute 
 power, whatever may be said of his pretensions. It may 
 be said that these facts go to prove the phenomena of 
 Mesmerism. We have no objection to prove them if they 
 
MESMERISM. 
 
 73 
 
 be true. But we rather think they go directly to disprove 
 Mesmerism, and establish a set of facts which show that if 
 Mesmerism were true if it had really discovered the key 
 to producing by artificial means that which Nature pro- 
 duces by eccentric action and disease then it ought to 
 have no failures in the application of its key, and ought 
 to meet with no impracticable and no unimpressible 
 subjects. Mesmerists confess that there are individuals 
 who cannot be mesmerised ; but the facts we have been 
 dealing with are facts to which all men are subject. And 
 if Mesmerists cannot produce these uniformly in all, 
 and with perfect certainty, their failure gives a strong 
 probability to the suspicion that they have not the 
 true key to produce them in any one, and that their ex- 
 periments, so far as they have any truthfulness in them, 
 are wholly empirical, of uncertain issue, and unworthy 
 of yet being recognized as having established anything 
 within the legitimate precincts of science. Our aim is 
 neither to support Mesmerism and its pretensions, nor to 
 be severe against anything on account of which its 
 adherents honestly think it can really lay claim to con- 
 sideration. The aim here is to direct inquiry and 
 attention to what is known to be truth, and stimulate 
 investigation in the right direction. It is quite plain 
 that nature does accomplish in a natural way phenomena 
 and effects fully as wonderful as anything mesmerism has 
 asserted; and if mesmerists think it of importance to 
 produce similar effects, let them turn to the means by 
 which Nature itself operates, and they may have some 
 prospect of making discoveries more worthy of con- 
 sideration than the pretensions of quacks, and more 
 uniform in their results than the accident of unaccount- 
 able susceptibilities. 
 
 With regard to Electro-Biology and Phrenology, which 
 are closely connected with this subject, it is perhaps right 
 
74 BEING AND FACULTIES OF MAN. 
 
 that we should also say something, because here too a 
 great deal of falsehood appears to have got mixed up with 
 a very small amount of physical truth. No anatomist 
 asserts in these days, if indeed anatomists ever made 
 the assertion, that the brain is an inorganic mass of 
 medullary Chaos, or that its various parts have not distinct 
 functions and purposes, whatever these may be ; but it 
 is the pretension made by the phrenologist to forecast 
 human character by reading the " Organs," and predicate 
 even criminal and other life by talking of " propensities " 
 founded on organic development and the relative 
 dimensions of so-called faculties, that produces scientific 
 repugnance and the well-founded disgust of sensible 
 men. Assuming, for the sake of argument, that phrenolo- 
 gists have been successful in localising the various organs 
 of the brain which they have named in their charts and 
 busts, how do they prove, let us ask, that the size of an 
 organ, or the relative size of a set of organs, proves 
 a propensity, or justifies the predication of a character 
 therefrom ? Does the size of a man's hand, or the physical 
 formation and power of his arm, prove, because he possesses 
 great strength, that he is fond of hard labour, or has a 
 propensity for laborious pursuits ? We have seen little 
 and delicate men who have taken to manual industry and 
 become strong-armed by practice from the extremest 
 degree of primary weakness ; and physical giants, on the 
 other hand, who have never taken to greater toil than 
 that of the brain, nor wielded a much heavier weapon 
 than a goose quill. Nay, though a certain amount of 
 cerebral capacity is indicated by the form and dimensions 
 of the skull, there is nothing to indicate that the brain, 
 like the feeble arm, may not develop by exercise, or 
 collapse and diminish from the want of it ; nor to show 
 that portions of the brain may not be largely developed 
 and exercised at one period of life, and wholly unexercised 
 
PROPENSITY. 75 
 
 at another ; just as much as that a man who may have 
 toiled fifty years, and suddenly succeeds to fortune, or 
 slowly matures it during that period, all at once abandons 
 his hard physical labour, and becomes a mere overseer or 
 master, employing and directing the labour of others, 
 or retires altogether into the leisure of life. If size of 
 cerebral organization meant propensity instead of merely 
 power or capacity, the propensity would be persistently 
 and continuously manifested from the beginning to the 
 end of existence ; but many men's lives are only a per- 
 sistent contradiction to their cerebral development, as 
 much as the lives of others are a contradiction to their 
 energies and physical strength. No one can look on the 
 fine head of Shakespeare without being struck with the 
 impress of pre-eminent intellect which it bears ; but a 
 question with regard to it still arises whether Nature 
 gave this evidence precedently, and stamped the physical 
 formation with that calm and concentrated aspect of 
 mental energy and seated power, or whether the trium- 
 phant progress of achievement did not enlarge the 
 expression and open the windows of the soul, and thereby 
 mould the physical material to its exposition, just as 
 practice indues the right hand with its cunning, and modifies 
 the nervous and muscular development of the exercised arm 
 into harmony with its use. If there be such evidence for 
 propensity as phrenologists have contended, where is the 
 evidence for energetic achievement, and of culpable and 
 degrading neglect ? But it is utterly fatal to all this 
 argument upon assumption that Propensity is not Material, 
 nor an attribute of Matter. It is no more Material than we 
 have already shown Feeling to be. There is no other pro- 
 pensity known as an attribute of matter than the propen- 
 sities of gravitation, attraction, repulsion, and chemical 
 affinity, which are not living, but dead ; not inherent, but 
 factitious powers purely physical, and variable under 
 
76 BEING AND FACULTIES OF MAN. 
 
 varying physical circumstances. Moral propensity is a 
 vital and a living power wholly metaphysical, and 
 incapable therefore of being evidenced by the dimensions 
 of a physical organ, or the relative preponderance of 
 physical arrangements. The biologist who does not 
 know this is little better than a mere materialist, like 
 Epicurus, and must be profoundly ignorant of metaphysics, 
 without which such conclusions as he draws cannot 
 legitimately be even approached. Matter is but a fourth 
 part of the elements which go to the constitution of a 
 human being, as we have shown at the outset of these 
 chapters ; and the phrenologist who proceeds to assert the 
 existence of propensity on the bare evidence of physical 
 or material development omits consideration of three- 
 fourths of the elements necessary to the determination of 
 the subject, and is no wiser than he who, looking at a 
 set of palsied and paralytic limbs, would assert, on the 
 bare ground of their apparent size and formation, that 
 the possessor of them must be able to walk and leap. 
 Physical development can at best give partial evidence 
 of Capacity only., not of Propensity, and only partial evidence 
 we insist, for men are not uniformly strong in proportion 
 to their appearance of strength, nor uniformly active- 
 minded in proportion to their appearance or capacity, 
 or even possession of intellect. The intensity, the vigour, 
 and the quantity of the vital power, purely immaterial 
 and beyond the range of scientific investigation, have 
 much to do with character, as well as all the circumstances 
 which attend its development, and, as external influences, 
 test and call it into operation. And the quality and 
 texture of the material elements, when matter itself is 
 at last condescended on, has more to do with its sustained 
 activity and enduring power than that crude, primary, 
 and dominant assumption of the phrenologist the 
 superficial appearance of mere brute weight or quantity. 
 
EXERCISE AND DEVELOPMENT. 77 
 
 No sane man would trust the strength of a rope merely 
 because it is thick, any more than he would endeavour to 
 make a rope of sand because sand will bear his weight 
 when he stands upon it ; yet the phrenologist's predications 
 of human character are just as illogically based and 
 inferred as such conclusions and misdirected efforts 
 would be, and the honest mind, to which truth is every- 
 thing, cannot be too earnestly warned against them. A 
 good deal of what mental and moral power may be in 
 achievement is evidenced by the small piecemeal and 
 inglorious labours of that being, too much despised among 
 mankind the poor Plodder ; for just as the Bees send 
 forth a thousand workers to gather wax and honey for the 
 hive, which at the end of the flower season contains a 
 plentitude of treasure and fortune, so the Plodder, intent 
 on achieving some worthy aim beyond the instantaneous 
 energy of his powers, calculates the value of little by 
 little, and adds under the sanction of forbearing time 
 his thousandth time repeated contribution to his work, 
 until it at last swells by slow but steady increase into 
 the full development of his purpose, and he is enabled to 
 leave a monument of his industry behind him not less 
 respectable, sanctified as it is by the fortitude of patience 
 and the heroism of perseverance, and often as beneficial to 
 mankind as the triumphs and masterpieces of genius 
 itself. Who will say that small things are contemptible 
 only, or that the Ant is not the greater a giant from the 
 very disproportion between its pigmy personality and its 
 mighty hill the exponent of a grander and more heroic 
 will than genius oft can claim as its associate? And 
 so of these small mental organs in men, on the ground 
 of which phrenologists would predicate failure in the 
 intellectual achievements of life. It is the exercised 
 limb of the little man that contains the developed strength, 
 not the idle arm of the giant. And the intellect, too, 
 
78 BEING AND FACULTIES OF MAN. 
 
 improves by action. It is a mistake to suppose that the 
 skull is a hard incasement of bone which allows no 
 enlargement of its prisoner : it is an arch strong as a 
 groined vault of masonry to resist pressure from without, 
 but it is the very reversal of an arch, with all its powers 
 of resistance inverted and turned against itself, when 
 opposed to pressure from within. Let us then, by every 
 attribute of our manhood, resist and defy these miserable 
 doctrines that would foredoom our noblest powers, and 
 write the scaring word " impossibility " across our paths 
 the arrogant fiat of charlatans and quacks. No cranium, 
 no physical form of our organization, exhibits at the 
 outset of this life the full development of which it is 
 capable. Adequate exercise only can give it that. The 
 metaphysical part of our being is the dominant part 
 the animating, energising, and controlling power and 
 the physical is merely subjective to it, just as external 
 matter also is to the forces which operate upon it. It is 
 quite as baseless and arrogant an assumption to say 
 that the physical development is the cause of propensity, 
 as that it is the cause of feeling and of life. The very 
 reverse is the case ; for life, and feeling, and propensity, 
 on the contrary, are the causes of the physical develop- 
 ment, which never would grow an inch from childhood to 
 age but for them. It is impossible to reason further 
 therefore with those who, assuming the position of 
 philosophers, mistake the effect for the cause, and the 
 cause for the effect, and invert the whole principles of 
 logic and sequences of truth to arrive at their ridiculous 
 conclusions ; for to them truth must appear only to be 
 error, and error only to be truth an idiosyncracy as 
 compared with which even lunacy has some lucid intervals 
 in its favour. 
 
 But the result of all these various considerations of the 
 being and faculties of man, his internal Consciousness 
 
DANGER OF ERROR. 79 
 
 and his contact with and knowledge of external reality, 
 will serve very little purpose to us if we have not learned 
 from them higher and better powers of discrimination 
 than we were aware of before we began the study in 
 which we have been engaged if we have not learned 
 that there are three great regions with which our responsi- 
 bility, our high and accountable moral life is in contact : 
 that there is a reality around us consistent, truthful, and 
 at least as stable as ourselves, in which the scene of 
 present life is cast, and in reference to which its duties 
 have to be wrought out in such a manner that it is of the 
 highest consequence we should so use and learn to know 
 our faculties and powers as not to be negligent nor allow 
 ourselves to be deceived that there is a coming reality 
 in futurity before us, after the limited present has passed 
 away, likely to demand for its experience a higher fitness 
 in point of intelligence, capacity, and purity for its 
 realization and that there is also a region present now, 
 and possible for ever, in which error, contradiction, and 
 confusion hold, and may continue to hold, that Saturnalia 
 of distortion and misrepresentation, wilfully deceiving and 
 being deceived the only chaos full of reaction and horror 
 which it is possible to imagine can be or ever has been 
 realised in an Eternity presided over by Divine and im- 
 maculate intelligence where will is free and moral action 
 a responsibility a very Hell from the intensity and the 
 perpetuity of its more than maddening incompatibilities. 
 Eight and Wrong divide the universe by a clear, vivid 
 and unmistakable line ; on the one side of which is truth, 
 stable, sure and eternally trustworthy, and on the other 
 falsehood and interminable error a shifting quicksand, a 
 treacherous quagmire, blinding and betraying its reckless 
 victims the region of inextricable and fatal floundering 
 of everlasting self-contradiction. 
 
 In this age we are beset on all sides with dangers, and 
 
80 BEING AND FACULTIES OF MAN. 
 
 assailed with hazy philosophies propounded by didactic 
 theorists, who seem as industriously engaged against us as if 
 it were one of the highest merits of life to lead us astray. 
 Candour was some protection at one time, and, though it 
 is still indispensable to integrity of judgment, it requires 
 often high and cultivated intelligence along with it to 
 enable us fully to escape deception ; for the world has 
 accepted that mischievous and plausible error that every 
 man is entitled to have his own opinion, and apparently to 
 publicly proclaim and teach it a fallacy before which the 
 whole principles of sound and truthful reasoning are sub- 
 verted, and error endowed with universal licence. Per- 
 haps it may yet avail some reader of these pages to point 
 out that every one is not entitled to have his own opinion, 
 and that those who claim such a right do it at the expense 
 of their truthfulness and accuracy of judgment, and at the 
 peril of all the errors into which they mislead others 
 and are themselves certain to fall ; for we doubt whether 
 those who repeat this popular aphorism about opinion 
 know the difference between an Opinion and a Con- 
 viction. Let us ask then, is every man, or any man, 
 entitled to hold error when he has the option of re- 
 jecting it? Can he free himself of his moral respon- 
 sibility to hold the truth, and nothing but the truth ? 
 But what is Opinion ? Is it truth ? And if it be not 
 truth, is it anything but imtruth falsehood and error ? 
 To show that Opinion is not never is truth let us illus- 
 trate the difference between it and Conviction. When a 
 man looks upon an object before him, such as a tree, for 
 example, he cannot help perceiving that it is a tree he 
 cannot convince himself it is not a tree. Nay, though he 
 deny it to be a tree, his denial will not enable him to 
 believe it is not a tree. Its appearance and self-evidence 
 of what it is will not vary or alter to accommodate his 
 denial or wish to disbelieve it. The tree will continue, 
 
OPINION AND CONVICTION. 81 
 
 in spite of all his mental resistance, to appear and to be 
 just what it is and what he perceives it to be ; and such a 
 perception is a Conviction. It is self-evidenced and 
 independent of our will ; for a Conviction is a perception 
 either of the mind or the senses which is unalterable by 
 the exercise of will or choice. But suppose that two per- 
 sons looking at a tree go into a discussion as to the ago 
 of the tree which is not cut, and the age of which cannot 
 be accurately ascertained till it is cut and the transverse 
 section of the stem with its rings revealed and that, with- 
 out knowing anything of the number of those rings the 
 two persons dispute and argue, one, that the tree is only 
 eighty years old, the other, that it is upwards of a hundred 
 years these are Opinions. The one holds by the one 
 view, and the other holds by the other, on the maxim that 
 every one is entitled to his opinion, and that one man's 
 opinion is as good as another. Yes, but what of the 
 truth involved ? Will the tree become only eighty years 
 old to please the one person, or a hundred years old to 
 please the other ? Are the opinions worth anything as a 
 matter of fact where the absolute truth, and it alone, is 
 requisite ? And when is it not requisite, if anything be 
 requisite about the matter at all ? Can either opinion be 
 relied on and accepted as truth if a question of the slightest 
 importance depended upon it ? They may be called ap- 
 proximations to the truth. But are approximations the 
 truth ? And is anything that is not the truth other than 
 untruth ? In every instance in which the actual truth is 
 required an opinion is worth absolutely nothing. Con- 
 viction is a perception of the truth itself ; Opinion is only 
 a guess at it. No man is entitled to hold it as the truth, 
 or act upon it as such, for it is plain that he can at will 
 change his opinions, but the truth will not change. 
 
 But we are told that men must form opinions and act 
 upon them in the business of life. Perhaps many men 
 
 a 
 
82 BEING AND FACULTIES OF MAN. 
 
 do so ; but let us show the fallacy of their so doing by au 
 illustration. Very lately a celebrated African traveller 
 was said to have been murdered by savage natives while 
 pursuing his magnanimous journey in the interior of that 
 country. When the news reached England, they were 
 fully credited by some and wholly discredited by 
 others. Neither of these parties by believing or dis- 
 believing could fix the actual fact ; their views of the 
 matter were mere opinions. But what we have to do with 
 here is, whether these opinions, either or both of them, 
 were, or could be, of any use as the basis of any action 
 that required to be taken in the circumstances. If the 
 parties who believed the illustrious traveller to be dead 
 were to take any action, what could their action be on the 
 basis of their opinion ? Could it be anything more than 
 merely to send out at their leisure and ascertain the 
 reality of the fact, which they held to be true already 
 hurry in the matter being unnecessary and out of the 
 question, because the traveller they were satisfied was 
 really dead ? On the other hand, what action could those 
 who did not believe the news of the traveller's murder 
 take on the basis of their opinion? Was it necessary 
 for them to do anything at all, seeing they were satisfied 
 that all was right ? It would be to discredit the wisdom 
 of their own opinion were they to do anything. Where, 
 then, is the value of opinion as a basis of action in such a 
 case? and where is there any case to which it better 
 applies? Any action taken by those who considered it 
 necessary to act in the case of the eminent traveller we 
 have mentioned was not taken on the basis of these 
 opinions, but by steering clear altogether of them. It did 
 occur in a sensible way, and as matter of fact, that certain 
 of the companions of the traveller's journey had returned 
 that was matter of fact. Part of the contemplated strength 
 of the enterprise was not with it, whatever its condition 
 
OPINION AND CONVICTION. 83 
 
 might be. It was therefore obvious as matter of fact and 
 of duty that we were bound to send out aid to replace 
 the ascertained deficiency, so that, if in time, it might not 
 be required in vain. These were truths and obligations 
 not opinions arrogantly expressed, but duty clearly ascer- 
 tained, without absolutely fixing anything but the wisdom 
 of distrusting opinions altogether. True, we are told that 
 men take and act on legal opinions day by day. But 
 this is really a confusion of ideas arising from mis- 
 application of language. A lawyer has the facts of a case 
 laid before him, and a sound lawyer states what the law 
 is in reference to these facts, not what in his opinion it is ; 
 not what he thinks, but what he knows it to be ; and just 
 in proportion as he states what he competently knows is 
 he a prudent adviser, and as he states what he merely 
 thinks is he utterly unsafe. 
 
 A mere opinion, even from a lawyer, is of very little 
 value, and the word is really a misnomer for the purpose 
 to which it is so applied in law. Clients wish to be in- 
 formed of the law which is certainly applicable to their 
 case, not of that uncertain thing opinion, the accuracy of 
 which has no present certainty, but has wholly to be 
 ascertained by a future result. Opinionative people are 
 great self-deceivers, and besides being very dogmatic 
 members of society, they are the most easy of all to be 
 misled. They are continually encountering those who 
 cannot be made, and are under no obligation, to think as 
 they do, but who could, if they chose to flatter, easily 
 encourage error rather than oppose it, with the most 
 obvious disadvantage to the opinionist. Surely such 
 people should take warning for their own sakes, as well 
 as for the comfort of others, to refrain from making 
 dogmatists of themselves ; for after all their labour and 
 persistency their opinions are really worth nothing. It 
 is a very small unction to lay to their souls to say their 
 
84 BEING AND FACULTIES OF MAN. 
 
 opinions are as good as the opinions of others ; for all 
 opinions are utterly worthless, and there is but one set of 
 fools greater than those who pertinaciously insist on 
 having their opinions respected, namely, those who 
 respect them. If there be noisy discussion and intem- 
 perate language it is sure to be over an opinion indis- 
 creetly maintained, and not over a truth that it is held, 
 for opinionative people spend many words and much 
 labour to prove Nothing. They may as well rest assured 
 at once that Truth is everything, and that, besides Truth, 
 there is only Error. But if they will not discipline their 
 own minds to appreciate this fact, how can they expect to 
 be armed by accurate logical habit to correct the errors 
 fallen into, or, worse and more dangerous still, the 
 impostures practised by others ? It ought ever to be re- 
 membered that opinion* are conclusions in the dark, and 
 before the truth is ascertained, about which all minds may 
 justifiably differ. 
 
 Assertion of Opinion, therefore, provokes only certain 
 and inevitable defeat, for in such encounters the person 
 who merely disputes the Opinion is not and never can be 
 in the wrong. It is the person who asserts the Opinion 
 who is in error, for the simple reason that Opinion is not 
 truth, and that in the absence of the truth the Opinion 
 cannot justifiably be insisted on. After the truth is 
 apparent, and can no longer be resisted, the region of 
 Opinion disappears, and anything but Conviction is im- 
 possible. 
 
 So much, then, for the proposition tliat every one is 
 entitled to have his own Opinion, which is only the most 
 arrogant assertion that can possibly bo propounded by 
 those who are determined at all hazards to stick to and 
 justify their errors, and inflict on others their own im- 
 perious, petulant, and blundering wilfulncss. Truth, and 
 that manifestation of it which justifies Conviction, will 
 
OPINION AND CONVICTION. 85 
 
 very rarely be disputed or mistaken, but Opinion can 
 never justifiably claim to be acquiesced in. It may be 
 modestly stated, but never as more than an Opinion, and 
 it would be better even then that it should wait till it is 
 asked for. 
 
 We have endeavoured, and the task is by no means 
 an easy one, nor one on the results of which we can very 
 greatly congratulate ourselves, to popularise within a 
 reasonable limit one of the most abstruse and important 
 departments of philosophy, strictly in unison with, though 
 antecedent to the subject of Natural Magic, and which 
 deserves from mankind a much more respectful attention 
 than it obtains as a means of self-knowledge, demonstra- 
 tion, and mental direction. Many of our readers will 
 probably have tired of the subject before reaching the 
 present page, even though our matter has been necessarily 
 limited to our space, and to the aim of dealing lucidly 
 and fully with a few, rather than ponderously and exhaus- 
 tively with many things ; for our facts have been selected 
 and explained at considerable length for the purpose 
 of showing that there are elements essential to accuracy 
 of judgment which are greatly neglected in the age 
 in which we live : an age in which correct and com- 
 petent judgment is pre-eminently required to guard 
 against deceptions ever increasing, and becoming more 
 subtle and intricate in their character from the ad- 
 vancing discovery of new scientific facts and appli- 
 ances. If these chapters are the means of showing 
 without undue tediousness to those who do care for 
 such subjects the powers of accurate perception and 
 conviction at our command, and the absence of any 
 necessity for forming fixed and positive opinions on 
 matters of which we are not thoroughly certain that 
 no mere opinion is worth forming .after all that the 
 judgment may in all cases IK safdy and wisely suspended 
 
00 BEING AND FACULTIES OF MAN. 
 
 without any practical inconvenience till the truth itself appears 
 let us hope they will sufficiently arm the prudent and 
 those who have a due respect for wisdom. Those who 
 prefer to learn in the school of experience must be left 
 to the lessons that instructor applies. 
 
LETTERS ON NATURAL MAGIC. 
 
LETTERS ON NATURAL MAGIC, 
 
 SIR WALTER SCOTT, BART. 
 
 LETTER I. 
 
 Extent and interest of the subject Science employed by ancient govern- 
 ments to deceive and enslave their subjects Influence of the super- 
 natural upon ignorant minds Means employed by the ancient 
 magicians to establish their authority Derived from a knowledge 
 of tlie phenomena of Nature From the influence of narcotic- 
 drugs upon the victims of their delusion From every branch, of 
 science Acoustics Hydrostatics Mechanics Optics M. Sal- 
 verte's work on the occult sciences Object of the following Letters. 
 
 MY DEAR SIR WALTER, 
 
 As it was at your suggestion that I undertook to 
 draw up a popular account of those prodigies of the 
 material world which have received the appellation of 
 Natural Magic, I have availed myself of the privilege of 
 introducing it under the shelter of your name. Although 
 I cannot hope to produce a volume at all approaching 
 in interest to that which you have contributed to the 
 Family Library, yet the popular character of some of 
 the topics which belong to this branch of Demonology 
 may atone for the defects of the following Letters ; and I 
 shall deem it no slight honour if they shall be considered 
 as forming an appropriate supplement to your valuable 
 work. 
 
90 LETTERS ON NATURAL MAGIC. 
 
 The subject of Natural Magic is one of great extent 
 as well as of deep interest. In its widest range, it 
 embraces the history of the governments and the super- 
 stitions of ancient times, of the means by which they 
 maintained their influence over the human mind, of the 
 assistance which they derived from the arts and the sciences, 
 and from a knowledge of the powers and phenomena of 
 nature. When the tyrants of antiquity were unable or 
 unwilling to found their sovereignty on the affections and 
 interests of their people, they sought to entrench them- 
 selves in the strongholds of supernatural influence, and to 
 rule with the delegated authority of heaven. The prince, 
 the priest, and the sage, were leagued in a dark conspiracy 
 to deceive and enslave their species ; and man who re- 
 fused his submission to a being like himself, became the 
 obedient slave of a spiritual despotism, and willingly 
 bound himself in chains when they seemed to have been 
 forged by the gods. 
 
 This system of imposture was greatly favoured by the 
 ignorance of these early ages. The human mind is at all 
 times fond of the marvellous, and the credulity of the 
 individual may be often measured by his own attachment 
 to the truth. When knowledge was the property of only 
 one caste, it was by no means difficult to employ it in the 
 subjugation of the great mass of society. An acquaintance 
 with the motions of the heavenly bodies, and the varia- 
 tions in the state of the atmosphere, enabled its possessor 
 to predict astronomical and meteorological phenomena 
 with a frequency and an accuracy which could not fail 
 to invest him with a divine character. The power of 
 bringing down fire from the heavens, even at times when 
 the electric influence was itself in a state of repose, could 
 be regarded only as a gift from heaven. The power of 
 rendering the human body insensible to fire was an irre- 
 sistible instrument of imposture ; and in the combinations 
 
BESOURCES OF THE ANCIENT MAGIC. 91 
 
 of chemistry, and the influence of drugs and soporific 
 embrocations on the human frame, the ancient magicians 
 found their most available resources. 
 
 The secret use which was thus made of scientific dis- 
 coveries 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. 
 
 The science of Acoustics furnished the ancient sorcerers 
 with some of their best deceptions. The imitation of 
 thunder in their subterranean temples could not fail to 
 indicate the presence of a supernatural agent. The 
 golden virgins whose ravishing voices resounded through 
 the temple of Delphos ; - the stone from the river Pac- 
 tolus, whose trumpet notes scared the robber from the 
 treasure which it guarded ; the speaking head which 
 uttered its oracular responses at Lesbos ; and the vocal 
 statue of Memnon, which began at the break of day to 
 accost the rising sun, were all deceptions derived from 
 science, and from a diligent observation of the phenomena 
 of nature. 
 
 The principles of Hydrostatics were equally available 
 in the work of deception. The marvellous fountain 
 which Pliny describes in the Island of Andros as dis- 
 charging wine for seven days, and water during the rest 
 of the year, the spring of oil which broke out in Rome 
 to welcome the return of Augustus from the Sicilian war, 
 the three empty urns which filled themselves with wine 
 at the annual feast of Bacchus in the city of Elis, the 
 
92 LETTERS ON NATURAL MAGIC. 
 
 glass tomb of Belus which was full of oil, and which, 
 when once emptied by Xerxes, could not again be filled, 
 the weeping statues, and the perpetual lamps of the 
 ancients, were all the obvious effects of the equilibrium 
 and pressure of fluids. 
 
 Although we have no direct evidence that the philo- 
 sophers of antiquity were skilled in Mechanics, yet there 
 are indications of their knowledge, by no means equivocal, 
 in the erection of the Egyptian obelisks, and in the 
 transportation of huge masses of stone, and their sub- 
 sequent elevation to great heights in their temples. The 
 powers which they employed, , and the mechanism by 
 which they operated, have been studiously concealed, but 
 their existence may be inferred from results otherwise 
 inexplicable, and the inference derives additional con- 
 firmation from the mechanical arrangements which seem 
 to have formed a part of their religious impostures. 
 When in some of the infamous mysteries of ancient Borne, 
 the unfortunate victims were carried off by the gods, there 
 is reason to believe that they were hurried away by the 
 power of machinery ; and when Apollonius, conducted by 
 the Indian sages to the temple of their god, felt the earth 
 rising and falling beneath his feet like the agitated sea, 
 he was no doubt placed upon a moving floor capable of 
 imitating the heavings of the waves. The rapid descent 
 of those who consulted the oracle in the cave of Tro- 
 phonius, the moving tripods which Apollonius saw in 
 the Indian temples, the walking statues at Antium, and 
 in the Temple of Hierapolis, and the wooden pigeon of 
 Archytas, are specimens of the mechanical resources of 
 the ancient magic. 
 
 But of all the sciences Optics is the most fertile in 
 marvellous expedients. The power of bringing the re- 
 motest objects within the very grasp of the observer, and 
 of swelling into gigantic magnitude the almost invisible 
 
GENERAL OBJECT OF THE WORK. 93 
 
 bodies of the material world, never fails to inspire with 
 astonishment even those who understand the means by 
 which these prodigies are accomplished. The ancients, 
 indeed, were not acquainted with those combinations of 
 lenses and mirrors which constitute the telescope and the 
 microscope, but they must have been familiar with the 
 property of lenses and mirrors to form erect and inverted 
 images of objects. There is reason to think that they 
 employed them to effect the apparition of their gods ; and 
 in some of the descriptions of the optical displays which 
 hallowed their ancient temples, we recognize all the 
 transformations of the modern phantasmagoria. 
 
 It would be an interesting pursuit to embody the 
 information which history supplies respecting the fables 
 and incantations of the ancient superstitions, and to show 
 how far they can be explained by the scientific knowledge 
 which then prevailed. This task has, to a certain extent, 
 been performed by M. Eusebe Salverte, in a work on the 
 occult sciences, which has recently appeared; but not- 
 withstanding the ingenuity and learning which it dis- 
 plays, the individual facts are too scanty to support the 
 speculations of the author, and the descriptions are too 
 meagre to satisfy the curiosity of the reader.* 
 
 In the following letters I propose to take a wider 
 range, and to enter into more minute and popular details. 
 The principal phenomena of nature, and the leading com- 
 binations of art, which bear the impress of a supernatural 
 character, will pass under our review, and our attention 
 will be particularly called to those singular illusions of 
 sense, by which the most perfect organs either cease to 
 
 * "We must caution the young reader against some of the views 
 given in M. Salverte's work. In his anxiety to account for every 
 thing miraculous by natural causes, he has ascribed to the same 
 origin some of those events in sacred history which Christians cannot 
 but regard as the result of diyine agency. 
 
94 LETTERS ON NATURAL MAGIC. 
 
 perform their functions, or perform them faithlessly ; and 
 where the efforts and the creations of the mind pre- 
 dominate over the direct perceptions of external nature. 
 
 In executing this plan, the task of selection is rendered 
 extremely difficult, by the superabundance of materials, 
 as well as from the variety of judgments for which these 
 materials must be prepared. Modern science may be 
 regarded as one vast miracle, whether we view it in 
 relation to the Almighty Being, by whom its objects and 
 its laws were formed, or to the feeble intellect of man, by 
 which its depths have been sounded, and its mysteries 
 explored : And if the philosopher who is familiarized 
 with its wonders, and who has studied them as necessary 
 results of general laws, never ceases to admire and adore 
 their Author, how great should be their effect upon less 
 gifted minds, who must ever view them in the light oi 
 inexplicable prodigies. Man has in all ages sought for a 
 sign from heaven, and yet he has been habitually blind to 
 the millions of wonders with which he is surrounded. If 
 the following pages should contribute to abate this de- 
 plorable indifference to all that is grand and sublime in 
 the universe, and if they should inspire the reader with a 
 portion of that enthusiasm of love and gratitude which 
 can alone prepare the mind for its final triumph, the 
 labours of the author will not have been wholly fruitless. 
 
POWER AND STRUCTURE OF THE EYE. 95 
 
 LETTER II. 
 
 The Eye the most important of our organs Popular description of it 
 The eye is the most fertile source of mental illusions Disappear- 
 ance of objects when their images 'fall upon the base of the optic 
 nerve Disappearance of objects when seen obliquely Deceptions 
 arising from viewing objects in a faint light Luminous figures 
 created by pressure on the eye either from external causes or from 
 the fulness of the blood-vessels Ocular spectra or accidental 
 colours Remarkable effects produced by intense light Influence 
 of the imagination in viewing these spectra Remarkable illusion 
 produced by this affection of the eye Duration of impressions of 
 light on the eye Thaumatrope Improvements upon it suggested 
 Disappearance of halves of objects or of one of two persons In~ 
 sensibility of the eye to particular colours Remarkable optical 
 illusion described. 
 
 OF all the organs by which we acquire a knowledge of 
 external nature the eye is the most remarkable and the 
 most important. By our other senses the information we 
 obtain is comparatively limited. The touch and the taste 
 extend no further than the surface of our own bodies. 
 The sense of smell is exercised within a very narrow 
 sphere, and that of recognizing sounds is limited to the 
 distance at which we hear the bursting of a meteor and 
 the crash of a thunderbolt. But the eye enjoys a bound- 
 less range of observation. It takes cognizance not only 
 of other worlds belonging to the solar system, but of other 
 systems of worlds infinitely removed into the immensity 
 of space ; and when aided by the telescope, the invention 
 of human wisdom, it is able to discover the forms, the 
 phenomena, and the movements of bodies whose distance 
 
96 LETTERS ON NATURAL MAGIC. 
 
 is as inexpressible in language as it is inconceivable in 
 thought. 
 
 While the human eye has been admired by ordinary 
 observers for the beauty of its form, tho power of its 
 movements, and the variety of its expression, it has excited 
 the wonder of philosophers by the exquisite mechanism of 
 its interior, and its singular adaptation to the variety of 
 purposes which it has to serve. The eyeball is nearly 
 globular, and is about an inch in diameter. It is formed 
 externally by a tough opaque membrane called the sclerotic 
 coat, which forms the white of the eye, with the exception 
 of a small circular portion in front called the cornea. 
 This portion is perfectly transparent, and so tough in its 
 nature as to afford a powerful resistance to external 
 injury. Immediately within the cornea, and in contact 
 with it, is the aqueous humour, a clear fluid, which 
 occupies only a small part of the front of the eye. Within 
 this humour is the iris, a circular membrane with a hole 
 in its centre called the pupil. The colour of the eye 
 resides in this membrane, which has the curious property 
 of contracting and expanding so as to diminish or enlarge 
 the pupil, an effect which human ingenuity has not 
 been able even to imitate. Behind the iris is suspended 
 the crystalline lens in a fine transparent capsule or bag of 
 the same form with itself. It is then succeeded by the 
 vitreous humour, which resembles the transparent white of 
 an egg, and fills up the rest of the eye. Behind the 
 vitreous humour, there is spread out on the inside of the 
 eyeball a fine delicate membrane, called the retina, which 
 is an expansion of the optic nerve, entering the back of the 
 eye, and communicating with the brain. 
 
 A perspective view and horizontal section of the left 
 eye, shown in the annexed figure, will convey a popular 
 idea of its structure. It is, as it were, a small camera 
 obscura, by means of which the pictures of external 
 
OCULAR ILLUSIONS. 97 
 
 objects are painted on the retina, and in a way of which 
 we are ignorant, it conveys the impression of them to the 
 brain. 
 
 Fig. 1. 
 
 r 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 handwriting 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 super- 
 
98 LETTERS ON NATUEAL MAGIC. 
 
 natural agency becomes under ordinary circumstances 
 unavoidable. 
 
 Hence it is not only an amusing but an useful occupa- 
 tion 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. I shall 
 therefore proceed to explain those illusions which have 
 their origin in the eye, whether they are general, or only 
 occasionally exhibited in particular persons, and under 
 particular circumstances. 
 
 There are few persons aware that when they look with 
 one eye there is some particular object before them to which 
 they are absolutely blind. If we look with the right eye this 
 point is always about 15 to the right of the object which 
 we are viewing, or to the right of the axis of the eye or the 
 point of most distinct vision. If we look with the left eye 
 the point is as far to the left. In order to be convinced of 
 this curious fact, which was discovered by M. Mariotte, place 
 two coloured wafers upon a sheet of white paper at the 
 distance of three inches, and look at the left-hand wafer 
 with the right eye at the distance of about 11 or 12 inches, 
 taking care to keep the eye straight above the wafer, and 
 the line which joins the eyes parallel to the line which 
 joins the wafers. When this is done, and the left eye 
 closed, the right-hand wafer will no longer be visible. The 
 same effect will be produced if we close the right eye and 
 look with the left eye at the right-hand wafer. When we 
 examine the retina to discover to what part of it this insensi- 
 bility to light belongs, we find that the image of the in- 
 visible wafer has fallen on the base of the optic nerve, or the 
 place where this nerve enters the eye and expands itself to 
 form the retina. This point is shown in the preceding figure 
 by a convexity at the place where the nerve enters the eye. 
 
 But though light of ordinary intensity makes no im- 
 
DARK SPOT ON THE RETINA, ETC. 99 
 
 pression upon this part of the eye, a very strong light 
 does, and even when we use candles or highly luminous 
 bodies in place of wafers the body does not wholly dis- 
 appear, but leaves behind a faint cloudy light, without, 
 however, giving anything like an image of the object 
 from which the light proceeds. 
 
 When the objects are white wafers upon a black ground, 
 the white wafer absolutely disappears, and the space which 
 it covers appears to be completely black ; and as the light 
 which illuminates a landscape is not much different from 
 that of a white wafer, we should expect, whether we use 
 one or both eyes,* to see a black or a dark spot upon 
 every landscape, within 15 of the point which most 
 particularly attracts our notice. The Divine Artificer, 
 however, has not left his work thus imperfect. Though 
 the base of the optic nerve is insensible to light that falls 
 directly upon it, yet it has been made susceptible of 
 receiving luminous impressions from the parts which 
 surround it, and the consequence of this is, that when the 
 wafer disappears, the spot which it occupied, in place of 
 being black, has always the same colour as the ground 
 upon which the wafer is laid, being white when the wafer 
 is placed upon a white ground, and red when it is placed 
 upon a red ground. This curious effect may be rudely 
 illustrated by comparing the retina to a sheet of blotting- 
 paper, and the base of the optic nerve to a circular portion 
 of it covered with a piece of sponge. If a shower falls 
 upon the paper, the protected part will not be wetted by 
 the rain which falls upon the sponge that covers it, but in 
 a few seconds it will be as effectually wetted by the 
 moisture which it absorbs from the wet paper with which 
 
 * When both eyes are open, the object whose image falls upon 
 the insensible spot of the one eye is seen by the other, so that though 
 it is not invisible, yet it will only be half as luminous, and therefore 
 two dark spots ought to be seen. 
 
100 LETTERS ON NATURAL MAGIC. 
 
 it is surrounded. In like manner the insensible spot on 
 the retina is stimulated by a borrowed light, and the 
 apparent defect is so completely removed that its exist- 
 ence can be determined only by the experiment already 
 described. 
 
 Of the same character, but far more general in its effects, 
 and important in its consequences, is another illusion of 
 the eye which presented itself to me several years ago. 
 When the eye is steadily occupied in viewing any parti- 
 cular object, or when it takes a fixed direction while the 
 mind is occupied with any engrossing topic of speculation 
 or of grief, it suddenly loses sight of, or becomes blind to, 
 objects seen indirectly, or upon which it is not fully 
 directed. This takes place whether we use one or both 
 eyes, and the object which disappears will reappear with- 
 out any change in the position of the eye, while other 
 objects will vanish and revive in succession without any 
 apparent cause. If a sportsman, for example, is watching 
 with intense interest the motions of one of his dogs, his 
 companion, though seen with perfect clearness by indirect 
 vision, will vanish, and the light of the heath or of the 
 sky will close in upon the spot which he occupied. 
 
 In order to witness this illusion, put a little bit of 
 white paper on a green cloth, and within three or four 
 inches of it, place a narrow strip of white paper. At the 
 distance of twelve or eighteen inches, fix one eye steadily 
 upon the little bit of white paper, and in a short time a 
 part or even the whole of the strip of paper will vanish as 
 if it had been removed from the green cloth. It will 
 again reappear, and again vanish, the effect depending 
 greatly on the steadiness with which the eye is kept fixed. 
 This illusion takes place when both the eyes are open, 
 though it is easier to observe it when one of them is 
 closed. The same thing happens when the object is 
 luminous. When a candle is thus seen by indirect vision, 
 
OBLIQUE VISION FEEBLE LIGHT. 101 
 
 it never wholly disappears, but it spreads itself out into a 
 cloudy mass, the centre of which is blue, encircled with a 
 bright ring of yellow light. 
 
 This inability of the eye to preserve a sustained vision 
 of objects seen obliquely, is curiously compensated by 
 the greater sensibility of those parts of the eye that have 
 this defect. The eye has the power of seeing objects 
 with perfect distinctness, only when it is directed straight 
 upon them ; that is, all objects seen indirectly are seen 
 indistinctly ; but it is a curious circumstance, that when 
 we wish to obtain a sight of a very faint star, such as one 
 of the satellites of Saturn, we can see it most distinctly 
 by looking away from it, and when the eye is turned full 
 upon it, it immediately disappears. 
 
 Effects still more remarkable are produced in the eye 
 when it views objects that are difficult to be seen from the 
 small degree of light with which they happen to be 
 illuminated. The imperfect view which we obtain of 
 such objects forces us to fix the eye more steadily upon 
 them ; but the more exertion we make to ascertain what 
 they are, the greater difficulties do we encounter to 
 accomplish our object. The eye is actually thrown into a 
 state of the most painful agitation, the object will swell 
 and contract, and partly disappear, and it will again 
 become visible when the eye has recovered from the 
 delirium into which it has been thrown. This phenomenon 
 may be most distinctly seen when the objects in a room 
 are illuminated with the feeble gleam of a fire almost 
 extinguished ; but it may be observed in daylight by the 
 sportsman when he endeavours to mark upon the mono- 
 tonous heath the particular spot where moor -game has 
 alighted. Availing himself of the slightest difference of 
 tint in the adjacent heath, he keeps his eye steadily fixed 
 on it as he advances, but whenever the contrast of illumina- 
 tion is feeble, he will invariably lose sight of his mark, 
 
102 LETTERS ON NATURAL MAGIC. 
 
 and if the retina is capable of taking it up, it is only to 
 lose it a second time. 
 
 This illusion is likely to be most efficacious in the 
 dark, when there is just sufficient light to render white 
 objects faintly visible, and to persons who are either timid 
 or credulous must prove a frequent source of alarm. Its 
 influence too is greatly aided by another condition of the 
 eye, into which it is thrown during partial darkness. 
 The pupil expands nearly to the whole width of the iris 
 in order to collect the feeble light which prevails ; but it 
 is demonstrable that in this state the eye cannot accom- 
 modate itself to see near objects distinctly, so that the 
 forms of persons and things actually become more shadowy 
 and confused when they come within the very distance 
 at which we count upon obtaining the best view of them. 
 These affections of the eye are, we are persuaded, very fre- 
 quent causes of a particular class of apparitions which are 
 seen at night by the young and the ignorant. The spectres 
 which are conjured up are always ivhite, because no other 
 colour can be seen, and they are either formed out of inani- 
 mate objects which reflect more light than others around 
 them, or of animals or human beings whose colour or change 
 of place renders them more visible in the dark. When 
 the eye dimly descries an inanimate object whose different 
 parts reflect different degrees of light, its brighter parts 
 may enable the spectator to keep up a continued view of 
 it ; but the disappearance and reappearance of its fainter 
 parts, and the change of shape which ensues, will ne- 
 cessarily give it the semblance of a living form, and if it 
 occupies a position which is unapproachable, and where 
 animate objects cannot find their way, the mind will soon 
 transfer to it a supernatural existence. In like manner a 
 human figure shadowed forth in a feeble twilight may 
 undergo similar changes, and after being distinctly seen 
 while it is in a situation favourable for receiving and 
 
PHOSPHORESCENCE OF THE RETINA. 103 
 
 reflecting light, it may suddenly disappear in a position 
 fully before, and within the reach of, the observer's eye ; 
 and if this evanescence takes place in a path or road 
 where there was no side-way by which the figure could 
 escape, it is not easy for an ordinary mind to efface the 
 impression which it cannot fail to receive. Under such 
 circumstances, we never think of distrusting an organ 
 which we have never found to deceive us ; and the truth 
 of the maxim that " seeing is believing," is too universally 
 admitted, and too deeply rooted in our nature to admit on 
 any occasion of a single exception. 
 
 In these observations we have supposed that the spec- 
 tator bears along with him no fears or prejudices, and is 
 a faithful interpreter of the phenomena presented to his 
 senses ; but if he is himself a believer in apparitions, and 
 unwilling to receive an ocular demonstration of their 
 reality, it is not difficult to conceive the picture which 
 will be drawn when external objects are distorted and 
 caricatured by the imperfect indications of his senses, 
 and coloured with all the vivid hues of the imagination. 
 
 Another class of ocular deceptions have their origin 
 in a property of the eye which has been very imperfectly 
 examined. The fine nervous fabric which constitutes the 
 retina, and which extends to the brain, has the singular 
 property of being phosphorescent by pressure. When we 
 press the eyeball outwards by applying the point of the 
 finger between it and the nose, a circle of light will be 
 seen, which Sir Isaac Newton describes as " a circle of 
 colours like those in the feather of a peacock s tail." He 
 adds, that " if the eye and the finger remain quiet, these 
 colours vanish in a second of time, but if the finger be 
 moved with a quavering motion they appear again." In 
 the numerous observations which I have made on these 
 luminous circles, I have never been able to observe any 
 colour but white, with the exception of a general red 
 
104 LETTERS ON NATURAL MAGIC. 
 
 tinge which is seen when the eyelids are closed, and 
 which is produced by the light which passes through 
 them. The luminous circles too always continue while 
 the pressure is applied, and they may be produced as 
 readily after the eye has been long in darkness as when it 
 has been recently exposed to light. When the pressure 
 is very gently applied, so as to compress the fine pulpy 
 substance of the retina, light is immediately created 
 when the eye is in total darkness ; and when in this state 
 light is allowed to fall upon it, the part compressed is 
 more sensible to light than any other part, and conse- 
 quently appears more luminous. If we increase the 
 pressure, the eyeball, being filled with incompressible 
 fluids, will protrude all round the point of pressure, and 
 consequently the retina at the protruded part will be 
 compressed by the outward pressure of the contained fluid, 
 while the retina on each side, namely, under the point of 
 pressure and beyond the protruded part, will be drawn 
 towards the protruded part or dilated. Hence the part 
 under the finger which was originally compressed is now 
 dilated, the adjacent parts compressed, and the more 
 remote parts immediately without this dilated also. Now 
 we have observed, that when the eye is, under these 
 circumstances, exposed to light, there is a bright luminous 
 circle shading off externally and internally into total 
 darkness. We are led therefore to the important con- 
 clusions, that when the retina is compressed in total 
 darkness it gives out light ; that when it is compressed 
 when exposed to light, its sensibility to light is increased ; 
 and that when it is dilated under exposure to light, it 
 becomes absolutely blind, or insensible to all luminous im- 
 pressions. 
 
 When the body is in a state of perfect health, this 
 phosphorescence of the eye shows itself on many occasions. 
 When the eye or the head receives a sudden blow, a 
 
EFFECTS OF PRESSURE ON THE RETINA. 105 
 
 bright flash of light shoots from the eyeball. In the act 
 of sneezing, gleams of light are emitted from each eye, 
 both during the inhalation of the air, and during its 
 subsequent protrusion, and in blowing air violently 
 through the nostrils, two patches of light appear above 
 the axis of the eye and in front of it, while other two 
 luminous spots unite into one, and appear as it were 
 about the point of the nose when the eyes are directed to 
 it. When we turn the eyeball by the action of its own 
 muscles, the retina is affected at the place where the 
 muscles are inserted, and there may be seen opposite 
 each eye and towards the nose, two semicircles of light, 
 and other two extremely faint towards the temples. At 
 particular times, when the retina is more phosphorescent 
 than at others, these semicircles are expanded into 
 complete circles of light. 
 
 In a state of indisposition, the phosphorescence of the 
 retina appears in new and more alarming forms. When 
 the stomach is under a temporary derangement accom- 
 panied with headache, the pressure of the blood-vessels 
 upon the retina shows itself, in total darkness, by a faint 
 blue light floating before the eye, varying in its shape, 
 and passing away at one side. This blue light increases 
 in intensity, becomes green and then yellow, and sometimes 
 rises to red, all these colours being frequently seen at 
 once, or the mass of light shades off into darkness. When 
 we consider the variety of distinct forms which in a state 
 of perfect health the imagination can conjure up when 
 looking into a burning fire, or upon an irregularly shaded 
 surface,* it is easy to conceive how the masses of coloured 
 
 * A very curious example of the influence of the imagination in 
 creating distinct forms out of an irregularly shaded surface, is 
 mentioned in the life of Peter Heaman, a Swede, who was executed 
 for piracy and murder at Leith in 1822. We give it in his own 
 words : [" One 
 
106 LETTEKS ON NATURAL MAGIC. 
 
 light which float before the eye may be moulded by the 
 same power into those fantastic and natural shapes which 
 so often haunt the couch of the invalid, even when the 
 mind retains its energy, and is conscious of the illusion 
 under which it labours. In other cases, temporary 
 blindness is produced by pressure upon the optic nerve, 
 or upon the retina, and under the excitation of fever or 
 delirium, when the physical cause which produces spectral 
 forms is at its height, there is superadded a powerful 
 influence of the mind, which imparts a new character to 
 the phantasms of the senses. 
 
 In order to complete the history of the illusions which 
 originate in the eye, it will be necessary to give some 
 account of the phenomena called ocular spectra, or acci- 
 dental colours. If we cut a figure out of red paper, and 
 placing it on a sheet of white paper, view it steadily for 
 some seconds with one or both eyes fixed on a particular 
 part of it, we shall observe the red colour to become less 
 brilliant. If we then turn the eye from the red figure 
 upon the white paper, we shall see a distinct green figure, 
 which is the spectrum, or accidental colour of the red 
 figure. With differently coloured figures we shall ob- 
 
 " One remarkable thing was, one day as we mended a sail, it 
 being a very thin one, after laying it upon deck in folds, I took the 
 tar-brush and tarred it over in the places which I thought needed 
 to be strengthened. But when we hoisted it up, I was astonished 
 to see that the tar I had put upon it represented a gallows and a 
 man under it without a head. The head was lying beside him. He 
 was complete, body, thighs, legs, arms, and in every shape like a 
 man. Now, I oftentimes made remarks upon it, and repeated them 
 to the others. I always said to them all, you may depend upon it 
 that something will happen. I afterwards took down the sail 
 on a calm day, and sewed a piece of canvas over the figure to cover 
 it, for I could not bear to have it always before my eyes.'' 
 
OCULAR SPECTRA. 107 
 
 serve differently coloured spectra, as in the following 
 table : 
 
 Colour of the Colour of the Spec- 
 
 Original figures. tral figures. 
 
 Eecl, Bluish-green. 
 
 Orange, Blue. 
 
 Yellow, Indigo. 
 
 Green, Keddish-violet. 
 
 Blue, Orange-red. 
 
 Indigo, Orange-yellow. 
 
 Violet, Yellow. 
 
 White, Black. 
 
 Black, White. 
 
 The two last of these experiments, viz., white and black 
 figures, may be satisfactorily made by using a white 
 medallion on a dark ground, and a black profile figure. 
 The spectrum of the former will be found to be black, 
 and that of the latter white. 
 
 These ocular spectra often show themselves without 
 any effort on our part, and even without our knowledge. 
 In a highly-painted room illuminated by the sun, those 
 parts of the furniture on which the sun does not directly 
 fall have always the opposite or accidental colour. If 
 the sun shines through a chink in a red window-curtain, 
 its light will appear green, varying, as in the above table, 
 with the colour of the curtain; and if we look at the 
 image of a candle reflected from the water in a Hue 
 finger glass, it will appear yellow. Whenever, in short, 
 the eye is affected with one prevailing colour, it sees at 
 the same time the spectral or accidental colour, just as 
 when a musical string is vibrating, the ear hears at the 
 same time its fundamental and its harmonic sounds. 
 
 If the prevailing light is white and very strong, the 
 spectra which it produces are no longer black, but of 
 various colours in succession. If we look at the sun, for 
 example, when near the horizon, or when reflected from 
 
108 LETTERS ON NATURAL MAGIC. 
 
 glass or water, so as to moderate its brilliancy, and keep 
 the eye upon it steadily for a few seconds, we shall see 
 even for hours afterwards, and whether the eye is open 
 or shut, a spectre of the sun varying in its colours. At 
 first, with the eye open, it is brownish-red with a sky-l)lue 
 border, and when the eye is shut, it is green with a red 
 border. The red becomes more brilliant, and the Uue 
 more vivid, till the impression is gradually worn off; but 
 even when they become very faint, they may be revived 
 by a gentle pressure on the eyeball. 
 
 Some eyes are more susceptible than others of these 
 spectral impressions, and Mr. Boyle mentions an indi- 
 vidual who continued for years to see the spectre of the 
 sun when he looked upon bright objects. This fact 
 appeared to Locke so interesting and inexplicable, that he 
 consulted Sir Isaac Newton respecting its cause, and 
 drew from him the following interesting account of a 
 similar effect upon himself : " The observation you mention 
 in Mr. Boyle's book of colours, I once made upon myself 
 with the hazard of my eyes. The manner was this : I 
 looked a very little while upon the sun in the looking- 
 glass with my right eye, and then turned my eyes into a 
 dark corner of my chamber, and winked, to observe the 
 impression made, and the circles of colours which encom- 
 passed it, and how they decayed by degrees, and at last 
 vanished. This I repeated a second and a third time. 
 At the third time, when the phantasm of light and 
 colours about it were almost vanished, intending my 
 fancy upon them to see their last appearance, I found, to 
 my amazement, that they began to return, and by little 
 and little to become as lively and vivid as when I had 
 newly looked upon the sun. But when I ceased to intend 
 my fancy upon them they vanished again. After this, I 
 found that, as often as I went into the dark, and intended 
 my mind upon them, as when a man looks earnestly to 
 
OCULAR SPECTRA. 109 
 
 see anything which is difficult to be seen, I could make 
 the phantasm return without looking any more upon the 
 sun ; and the oftener I made it return, the more easily I 
 could make it return again. And at length, by repeating 
 this without looking any more upon the sun, I made such 
 an impression on my eye, that, if I looked upon the 
 clouds, or a book, or any bright object, I saw upon it a 
 round bright spot of light like the sun, and, which is still 
 stranger, though I looked upon the sun with my right 
 eye only, and not with my left, yet my fancy began to 
 make an impression upon my left eye as well as upon my 
 right. For if I shut my right eye, and looked upon a 
 book or the clouds with my left eye, I could see the 
 spectrum of the sun almost as plain as with my right eye, 
 if I did but intend my fancy a little while upon it ; for at 
 first, if I shut my right eye, and looked with my left, the 
 spectrum of the sun did not appear till I intended my 
 fancy upon it ; but by repeating, this appeared every time 
 more easily. And now in a few hours' time I had brought 
 my eyes to such a pass, that I could look upon no bright 
 object with either eye but I saw the sun before me, so 
 that I durst neither write nor read ; but to recover the 
 use of my eyes, shut myself up in my chamber made 
 dark, for three days together, and used all means in my 
 power to direct my imagination from the sun. For if I 
 thought upon him, I presently saw his picture, though I 
 was in the dark. But by keeping in the dark, and em- 
 ploying my mind about other things, I began in three or 
 four days to have more use of my eyes again ; and by 
 forbearing to look upon bright objects, recovered them 
 pretty well ; though not so well but that, for some months 
 after, the spectrums of the sun began to return as often 
 as I began to meditate upon the phenomena, even though 
 I lay in bed at midnight with my curtains drawn. But 
 now I have been very well for many years, though I am 
 
110 LETTEES ON NATURAL MAGIC. 
 
 apt to think, if I durst venture my eyes, I could still 
 make the phantasm return by the power of my fancy. 
 This story I tell you, to let you understand, that in the 
 observation related by Mr. Boyle, the man's fancy 
 probably concurred with the impression made by the 
 sun's light to produce that phantasm of the sun which he 
 constantly saw in bright objects."* 
 
 I am not aware of any effects that had the character of 
 supernatural having been actually produced by the causes 
 above described ; but it is obvious, that, if a living figure 
 had been projected against the strong light which im- 
 printed these durable spectra of the stin, which might 
 really happen when the solar rays are reflected from 
 water, and diffused by its ruffled surface, this figure would 
 have necessarily accompanied all the luminous spectres 
 which the fancy created. Even in ordinary lights strange 
 appearances may be produced by even transient impres- 
 sions, and if I am not greatly mistaken, the case which 
 I am about to mention is not only one which may occur, 
 but which actually happened. A figure dressed in black 
 and mounted upon a white horse was riding along exposed 
 to the bright rays of the sun, which, through a small 
 opening in the clouds, was throwing its light only upon 
 that part of tjie landscape. The Hack figure was pro- 
 jected against a white cloud, and the white horse shone 
 with particular brilliancy by its contrast with the dark 
 soil against which it was seen. A person interested in 
 the arrival of such a stranger had been for some time 
 following his movements with intense anxiety, but upon 
 his disappearance behind a wood, was surprised to observe 
 the spectre of the mounted stranger in the form of a white 
 rider upon a black steed, and this spectre was seen for 
 some time in the sky, or upon any pale ground to which 
 the eye was directed. Such an occurrence, especially if 
 
 * See the Edinburgh Encyclopedia, Art. ACCIDENTAL COLOURS. 
 
DURATION OF LUMINOUS IMPRESSIONS. Ill 
 
 accompanied with a suitable combination of events, might, 
 even in modern times, have formed a chapter in the history 
 of the marvellous. 
 
 It is a curious circumstance, that when the image of 
 an object is impressed upon the retina only for a few 
 moments, the picture which is left is exactly of the same 
 colour with the object. If we look, for example, at a 
 window at some distance from the eye, and then transfer 
 the eye quickly to the wall, we shall see it distinctly but 
 momentarily with light panes and dark bars ; but in a 
 space of time incalculably short, this picture is succeeded 
 by the spectral impression of the window, which will con- 
 sist of black panes and white bars. The similar spectrum, 
 or that of the same colour as the object, is finely seen in the 
 experiment of forming luminous circles by whirling round 
 a burning stick, in which case the circles are always red. 
 
 In virtue of this property of the eye an object may be 
 seen in many places at once ; and we may even exhibit 
 at the same instant the two opposite sides of the same object, 
 or two pictures painted on the opposite sides of a piece of 
 card. It was found by a French philosopher, M. D'Arcet, 
 that the impression of light continued on the retina about 
 the eighth part of a second after the luminous body was 
 withdrawn, and upon this principle Dr. Paris has con- 
 structed the pretty little instrument, called the Thauma- 
 trope, or the Wonder-turner. It consists of a number of 
 circular pieces of card about two or three inches broad, 
 which may be twirled round with great velocity by the 
 application of the forefinger and thumb of each hand 
 to pieces of silk string attached to opposite points of 
 their circumference. On each side of the circular piece 
 of card is painted part of a picture, or a part of a figure, 
 in such a manner that the two parts would form a group 
 or a whole figure if we could see both sides at once. 
 Harlequin, for example, is painted on one side, and 
 
112 LETTERS ON NATURAL MAGIC. 
 
 Columbine on the other, so that by twirling round the 
 card the two are seen at the same time in their usual 
 mode of combination. The body of a Turk is drawn on 
 one side, and his head on the reverse, and by the rotation of 
 the card the head is replaced upon his shoulders. The 
 principle of this illusion may be extended to many other 
 contrivances. Part of a sentence may be written on one 
 side of a card and the rest on the reverse. Particular 
 letters may be given on one side, and others upon the 
 other, or even halves or parts of each letter may be put 
 upon each side, or all these contrivances may be com- 
 bined, so that the sentiment which they express can be 
 understood only when all the scattered parts are united 
 by the revolution of the card. 
 
 As the revolving card is virtually transparent, so that 
 bodies beyond it can be seen through it, the power of 
 the illusion might be greatly extended by introducing 
 into the picture other figures, either animate or inanimate. 
 The setting sun, for example, might be introduced into a 
 landscape : part of the flame of a fire might be seen to 
 issue from the crater of a volcano, and cattle grazing in a 
 field might make part of the revolutionary landscape. 
 For such purposes, however, the form of the instrument 
 would require to be completely changed, and the rotation 
 should be effected round a standing axis by wheels and 
 pinions, and a screen placed in front of the revolving 
 plane with open compartments or apertures, through 
 which the principal figures would appear. Had the 
 principle of this instrument been known to the ancients, 
 it would doubtless have formed a powerful engine of 
 delusion in their temples, and might have been more 
 effective than the optical means which they seem to have 
 employed for producing the apparitions of their gods. 
 
 In certain diseased conditions of the eye effects of a 
 very remarkable kind are produced. The faculty of seeing 
 
INSENSIBILITY TO COLOURS. 113 
 
 objects double is too common to be noticed as remarkable ; 
 and though it may take place with only one eye, yet, as 
 it generally arises from a transient inability to direct the 
 axes of both eyes to the same point, it excites little notice. 
 Thai! state of the eye, however, in which we lose sight 
 of half of every object at which we look, is more alarming 
 and more likely to be ascribed to the disappearance of 
 part of the object than to a defect of sight. Dr. Wollaston, 
 who experienced this defect twice, informs us that, after 
 taking violent exercise, he " suddenly found that he could 
 see but half of a man whom he met, and that, on attempt- 
 ing to read the name of JOHNSON over a door, he saw 
 only SON, the commencement of the name being 
 
 wholly obliterated from his view." In this instance, the 
 part of the object which disappeared was towards his left, 
 but on a second occurrence of the same affection, the part 
 which disappeared was towards his right. There are 
 many occasions on which this defect of the eye might 
 alarm the person who witnessed it for the first time. At 
 certain distances from the eye one of two persons would 
 necessarily disappear ; and by a slight change of position 
 either in the observer or the person observed, the person 
 that vanished would reappear, while the other would 
 disappear in his turn. The circumstances under which 
 these evanescences would take place could not be supposed 
 to occur to an ordinary observer., even if he should be 
 aware that the cause had its origin in himself. When 
 a phenomenon so strange is seen by a person in perfect 
 health, as it generally is, and who has never had occasion 
 to distrust the testimony of his senses, he can scarcely 
 refer it to any other cause than a supernatural one. 
 
 Among the affections of the eye which not only deceive 
 the person who is subject to them, but those also who 
 witness their operation, may be enumerated the insensi- 
 bility of the eye to particular colours. This defect is not 
 
114 LETTERS ON NATURAL MAGIC. 
 
 accompanied with any imperfection of vision, or connected 
 with any disease either of a local or a general nature, and it- 
 has hitherto been observed in persons who possess a strong 
 and a sharp sight. Mr. Huddart has described the case of 
 one Harris, a shoemaker, at Maryport, in Cumberland, 
 who was subject to this defect in a very remarkable 
 degree. He seems to have been insensible to every 
 colour, and to have been capable of recognizing only the 
 two opposite tints of black and white. " His first suspicion 
 of this defect arose when he was about four years old. 
 Having by accident found in the street a child's stocking, 
 he carried it to a neighbouring house to inquire for the 
 owner : he observed the people call it a red stocking, 
 though ho did not understand why they gave it that 
 denomination, as he himself thought it completely de- 
 scribed by being called a stocking. The circumstance, 
 however, remained in his memory, and, with other subse- 
 quent observations, led him to the knowledge of his defect. 
 He observed also that, when young, other children could 
 discern cherries on a tree by some pretended difference 
 of colour, though he could only distinguish them from 
 the leaves by their difference of size and shape. He 
 observed also that, by means of this difference of colour, 
 they could see the cherries at a greater distance than he 
 could, though he could see other objects at as great a 
 distance as they, that is, where the sight was not assisted 
 by the colour." Harris had two brothers whose perception 
 of colours was nearly as defective as his own. One of 
 these, whom Mr. Huddart examined, constantly mistook 
 light green for yellow, and orange for grass green. 
 
 Mr. Scott has described in the Philosophical Transac- 
 tions his own defect in perceiving colours. He states 
 that he does not know any green in the world ; that a pink 
 colour and a pale blue are perfectly alike ; that he has 
 often thought a full red and a full green a good match ; 
 
INSENSIBILITY TO COLOURS. 115 
 
 that he is sometimes baffled in distinguishing a full purple 
 from a deep blue, but that he knows light, dark, and 
 middle yellows, and all degrees of blue except sky-blue. 
 " I married my daughter to a genteel, worthy man, a few 
 years ago : the day before the marriage he came to my 
 house dressed in a new suit of fine cloth clothes. I was 
 much displeased that he should come, as I supposed, in 
 black ; and said that he should go back to change his 
 colour. But my daughter said, No No ; the colour is 
 very genteel ; that it was my eyes that deceived me. He 
 was a gentleman of the law, in a fine rich claret-coloured 
 dress, which is as much a black to my eyes as any black 
 that ever was dyed." Mr. Scott's father, his maternal 
 uncle, one of his sisters, and her two sons, had all the same 
 imperfection. Dr. Nichol has recorded a case where a 
 naval officer purchased a blue uniform coat and waistcoat 
 with red breeches to match the blue, and Mr. Harvey 
 describes the case of a tailor at Plymouth, who, on one 
 occasion, repaired an article of dress with crimson in place 
 of black silk, and on another, patched the elbow of a blue 
 coat with a piece of crimson cloth. It deserves to be 
 remarked that our celebrated countrymen the late Mr. 
 Dugald Stewart, Mr. Dalton, and Mr. Troughton, have a 
 similar difficulty in distinguishing colours. Mr. Stewart 
 discovered this defect when one of his family was admiring 
 the beauty of the Siberian crab-apple, which he could not 
 distinguish from the leaves but by its form and size. 
 Mr. Dalton cannot distinguish blue from pink, and the 
 solar spectrum consists only of two colours, yellow and 
 blue. Mr. Troughton regards red, ruddy pinks, and 
 brilliant oranges, as yellows, and greens as blues, so that 
 he is capable only of appreciating blue and yellow colours. 
 In all those cases which have been carefully studied, 
 at least in three of them in which I have had the advan- 
 tage of making personal observations, namely, those of 
 
116 LETTERS ON NATURAL MAGIC. 
 
 Mr. Troughton, Mr. Dalton, and Mr. Listen, the eye 
 is capable of seeing the whole of the prismatic spectrum, 
 the red space appearing to be yellow. If the red space 
 consisted of homogeneous or simple red rays, we should 
 be led to infer that the eyes in question were not insensible 
 to red light, but were merely incapable of discriminating 
 between the impressions of red and yellow light. I have 
 lately shown, however, that the prismatic spectrum 
 consists of three equal and coincident spectra of red, 
 yellow, and Hue light, and consequently, that much yellow 
 and a small portion of blue light exist in the red space ; 
 and hence it follows that those eyes which see only 
 two colours, viz., yellow and blue, in the spectrum, are 
 really insensible to the red light of the spectrum, and 
 see only the yellow with the small portion of blue with 
 which the red is mixed. The faintness of the yellow 
 light which is thus seen in the red space, confirms the 
 opinion that the retina has not appreciated the influence 
 of the simple red rays. 
 
 If one of the two travellers who, in the fable of the 
 chameleon, are made to quarrel about the colour of that 
 singular animal, had happened to possess this defect of 
 sight, they would have encountered at every step of their 
 journey new grounds of dissension without the chance 
 of finding an umpire who could pronounce a satisfactory 
 decision. Under certain circumstances, indeed, the arbiter 
 might set aside the opinions of both the disputants, and 
 render it necessary to appeal to some higher authority 
 
 to beg he'd tell 'em if he knew 
 
 Whether the thing was red or blue. 
 
 In the course of writing the preceding observations, an 
 ocular illusion occurred to myself of so extraordinary a 
 nature, that I am convinced it never was seen before, and 
 I think it far from probable that it will ever be seen 
 again. Upon directing my eyes to the candles that were 
 
REMARKABLE OPTICAL ILLUSION. 117 
 
 standing before me, I was surprised to observe, apparently 
 among my hair, and nearly straight above my head, and 
 far without the range of vision, a distinct image of one 
 of the candles inclined about 4.5 to the horizon, as shown 
 at A in Fig. 2. The image was as distinct and perfect 
 
 Fig. 2. 
 
 as if it had been formed by reflexion from a piece of 
 mirror glass, though of course much less brilliant, and 
 the position of the image proved that it must be formed 
 by reflexion from a perfectly flat and highly-polished 
 surface. But where such a surface could be placed, 
 and how, even if it were fixed, it could reflect the image 
 of the candle up through my head, were difficulties not 
 a little perplexing. Thinking that it might be something 
 lodged in the eyebrow, I covered it up from the light, 
 but the image still retained its place. I then examined 
 the eyelashes with as little success, and was driven to the 
 extreme supposition that a crystallization was taking 
 place in some part of the aqueous humour of the eye, and 
 that the image was formed by the reflexion of the light 
 of the candle from one of the crystalline faces. In this 
 
118 LETTERS ON NATURAL MAGIC. 
 
 state of uncertainty, and, I may add, of anxiety, for this 
 last supposition was by no means an agreeable one, I set 
 myself down to examine the phenomenon experimentally. 
 I found that the image varied its place by the motion of the 
 head and of the eyeball, which proved that it was either 
 attached to the eyeball or occupied a place where it was 
 affected by that motion. Upon inclining the candle at 
 different angles the image suffered corresponding variations 
 of position. In order to determine the exact place of the 
 reflecting substance, I now took an opaque circular body 
 and held it between the eye and the candle till it eclipsed 
 the mysterious image. By bringing the body nearer and 
 nearer the eyeball till its shadow became sufficiently 
 distinct to be seen, it was easy to determine the locality 
 of the reflector, because the shadow of the opaque body 
 must fall upon it whenever the image of the candle was 
 eclipsed. In this way I ascertained that the reflecting 
 body was in the upper eyelash, and I found that, in con- 
 sequence of being disturbed, it had twice changed its 
 inclination, so as to represent a vertical candle in the 
 horizontal position B, and afterwards in the inverted 
 position C. Still, however, I sought for it in vain, and 
 even with the aid of a magnifier I could not discover it. 
 At last, however, Mrs. B., who possesses the perfect vision 
 of short-sighted persons, discovered, after repeated exami- 
 nations, between two eyelashes, a minute speck, which, 
 upon being removed with great difficulty, turned out to be a 
 chip of red wax not above the hundredth part of an inch 
 in diameter, and having its surface so perfectly flat and 
 so highly polished that I could see in it the same image 
 of the candle, by placing it extremely near the eye. This 
 chip of wax had no doubt received its flatness and its 
 polish from the surface of a seal, and had started into my 
 eye when breaking the seal of a letter. 
 
 That this reflecting substance was the cause of the 
 
KEMARKABLE OPTICAL ILLUSION. 119 
 
 image of the candle cannot admit of a doubt; but the 
 wonder still remains how the images which it formed 
 occupied so mysterious a place as to be seen without 
 the range of vision, and apparently through the head. In 
 order to explain this, let m n, Fig. 2, be a lateral view of 
 the eye. The chip of wax was placed at m at the root of 
 the eyelashes, and being nearly in contact with the outer 
 surface of the cornea, the light of the candle which it re- 
 flected passed very obliquely through the pupil and fell 
 upon the retina somewhere to the left of n, very near 
 where the retina terminates; but a ray thus falling 
 obliquely on the retina is seen, in virtue of the law of 
 visible direction already explained, in a line n C perpen- 
 dicular to the retina at the point near n, where the ray 
 fell. Hence the candle was necessarily seen through the 
 head as it were of the observer, and without the range of 
 ordinary vision. The comparative brightness of the re- 
 flected image still surprises me ; but even this, if the 
 image really was brighter, may be explained by the fact, 
 that it was formed on a part of the retina upon which 
 light had never before fallen, and which may therefore 
 be supposed to be more sensible, than the parts of the 
 membrane in constant use, to luminous impressions. 
 
 Independent of its interest as an example of the mar- 
 vellous in vision, the preceding fact may be considered as 
 a proof that the retina retains its power to its very ter- 
 mination near the ciliary processes, and that the law of 
 visible direction holds true even without the range of 
 ordinary vision. It is therefore possible that a reflecting 
 surface favourably placed on the outside of the eye, or 
 that a reflecting surface in the inside of the eye, may 
 cause a luminous image to fall nearly on the extreme 
 margin of the retina, the consequence of which would be 
 that it would be seen in the back of the head half way 
 between a vertical and a horizontal line. 
 
120 LETTERS ON NATURAL MAGIC. 
 
 LETTER III. 
 
 Subject of spectral illusions Becent and interesting case of Mrs. A. 
 Her first illusion affecting the ear Spectral apparition of her 
 husband Spectral apparition of a cat Apparition of a near 
 and living relation in grave-clothes seen in a looking-glass Other 
 illusions affecting the ear Spectre of a deceased friend sitting in 
 an easy -chair Spectre of a coach and four filled with skeletons 
 Accuracy and value of the preceding cases State of health under 
 which they arose Spectral apparitions are pictures on the retina 
 The ideas of memory and imagination are also pictures on the 
 retina General views of the subject Approximate explanation of 
 spectral apparitions. 
 
 THE preceding account of the different sources of illusion 
 to which the eye is subject, is not only useful as indicating 
 the probable cause of any individual deception, but it has 
 a special importance in preparing the mind for understand- 
 ing those more vivid and permanent spectral illusions to 
 which some individuals have been either occasionally or 
 habitually subject. 
 
 In these lesser phenomena we find the retina so power- 
 fully influenced by external impressions as to retain the 
 view of visible objects long after they are withdrawn ; we 
 observe it to be so excited by local pressures of which we 
 sometimes know neither the nature nor the origin, as to 
 see in total darkness moving and shapeless masses of 
 coloured light ; and we find, as in the case of Sir Isaac 
 Newton and others, that the imagination has the power 
 of reviving the impressions of highly-luminous objects, 
 months and even years after they were first made. From 
 such phenomena, the mind feels it to be no violent transi- 
 
SPECTRAL ILLUSIONS. 121 
 
 tion to pass to those spectral illusions which, in particular 
 states of health, have haunted the most intelligent indi- 
 viduals, not only in the broad light of day, but in the 
 very heart of the social circle. 
 
 This curious subject has been so ably and fully treated 
 in your Letters on Demonology, that it would be presump- 
 tuous in me to resume any part of it on which you have 
 even touched ; but as it forms a necessary branch of a 
 Treatise on Natural Magic, and as one of the most remark- 
 able cases on record has come within my own knowledge, 
 I shall make no apology for giving a full account of the dif- 
 ferent spectral appearances which it embraces, and of adding 
 the results of a series of observations and experiments on 
 which I have been long occupied, with the view of throwing 
 some light on this remarkable class of phenomena. 
 
 A few years ago I had occasion to spend some days 
 under the same roof with the lady to whose case I have 
 above referred. At that time she had seen no spectral 
 illusions, .and was acquainted with the subject only from 
 the interesting volume of Dr. Hibbert. In conversing 
 with her about the cause of these apparitions, I mentioned 
 that, if she should ever see such a thing, she might distin- 
 guish a genuine ghost existing externally, and seen as an 
 external object, from one created by the mind, by merely 
 pressing one eye or straining them both so as to see objects 
 double ; for in this case the external object or supposed 
 apparition would invariably be doubled, while the impres- 
 sion on the retina created by the mind would remain 
 single. This observation recurred to her mind when she 
 unfortunately became subject to the same illusions ; but 
 she was too well acquainted with their nature to require 
 any such evidence of their mental origin ; and the state of 
 agitation which generally accompanies them- seems to 
 have prevented her from making the experiment as a 
 matter of curiosity. 
 
122 LETTERS ON NATURAL MAGIC. 
 
 1. The first illusion to which Mrs. A. was subject was 
 one which affected only the ear. On the 26th of De- 
 cember, 1830, about half-past four in the afternoon, she 
 was standing near the fire in the hall, and on the point 
 of going up stairs to dress, when she heard, as she sup- 
 posed, her husband's voice calling her by name, " 
 
 Come here ! come to me !" She imagined that he was 
 calling at the door to have it opened, but upon going 
 there and opening the door she was surprised to find no 
 person there. Upon returning to the fire, she again heard 
 the same voice calling out very distinctly and loudly, 
 
 " Come, come here!" She then opened two other 
 
 doors of the same room, and upon seeing no person she 
 returned to the fire-place. After a few moments she 
 
 heard the same voice still calling, " Come to me, come ! 
 
 come away !" in a loud, plaintive, and somewhat impa- 
 tient tone. She answered as loudly, " Where are you ? 
 I don't kcow where you are;" still imagining that he 
 was somewhere in search of her : but receiving no 
 answer she shortly went up stairs. On Mr. A/s return 
 to the house, about half an hour afterwards, she inquired 
 why he called to her so often, and where he was ; and she 
 was of course greatly surprised to learn that he had not 
 been near the house at the time. A similar illusion, 
 which excited no particular notice at the time, occurred to 
 Mrs. A. when residing at Florence about ten years before, 
 and when she was in perfect health. When she was un- 
 dressing after a ball, she heard a voice call her repeatedly 
 by name, and she was at that time unable to account for it. 
 
 2. The next illusion which occurred to Mrs. A. was of 
 a more alarming character. On the 30th of December, 
 about four o'clock in the afternoon, Mrs. A. came down 
 stairs into the drawing-room, which she had quitted only 
 a few minutes before, and on entering the room she saw 
 her husband, as she supposed, standing with his back to 
 
SPECTRAL ILLUSIONS. 123 
 
 the fire. As lie had gone out to take a walk about half an 
 hour before, she was surprised to see him there, and asked 
 him why he had returned so soon. The figure looked 
 fixedly at her with a serious and thoughtful expression of 
 countenance, but did not speak. Supposing that his mind 
 was absorbed in thought, she sat down in an arm-chair 
 near the fire, and within two feet at most of the figure, 
 which she still saw standing before her. As its eyes, how- 
 ever, still continued to be fixed upon her, she said after 
 
 the lapse of a few minutes, " Why don't you speak ?" 
 
 The figure immediately moved off 1 towards the window at 
 the farther end of the room, with its eyes still gazing on 
 her, and it passed so very close to her in doing so that 
 she was struck by the circumstance of hearing no step 
 nor sound, nor feeling her clothes brushed against, nor 
 even any agitation in the air. Although she was now con- 
 vinced that the figure was not her husband, yet she never 
 for a moment supposed that it was anything supernatural, 
 and was soon convinced that it was a spectral illusion. 
 As soon as this conviction had establised itself in her 
 mind, she recollected the experiment which I had suggested, 
 of trying to double the object ; but before she was able 
 distinctly to do this, the figure had retreated to the window, 
 where it disappeared. Mrs. A. immediately followed it, 
 shook the curtains and examined the window, the impres- 
 sion having been so distinct and forcible that she was 
 unwilling to believe that it was not a reality. Finding, 
 however, that the figure had no natural means of escape, 
 she was convinced that she had seen a spectral apparition 
 like those recorded in Dr. Hibbert's work, and she conse- 
 quently felt no alarm or agitation. The appearance was 
 seen in bright daylight, and lasted four or five minutes. 
 When the figure stood close to her it concealed the real 
 objects behind it, and the apparition was fully as vivid as 
 the reality. 
 
124 LETTEKS ON NATUKAL MAGIC. 
 
 3. On these two occasions Mrs. A. was alone, but when 
 the next phantasm appeared her husband was present. 
 This took place on the 4th of January, 1830. About ten 
 o'clock at night, when Mr. and Mrs. A. were sitting in 
 the drawing-room, Mr. A. took up the poker to stir the 
 fire, and when he was in the act of doing this, Mrs. A. 
 exclaimed, "Why there's the cat in the room! ""Where?" 
 asked Mr. A. " There, close to you," she replied. 
 " Where ?" he repeated. " Why on the rug to be sure, 
 between yourself and the coal-scuttle." Mr. A., who had 
 still the poker in his hand, pushed it in the direction 
 mentioned. " Take care," cried Mrs. A., " take care, you 
 are hitting her with the poker." Mr. A. again asked her 
 to point out exactly where she saw the cat. She replied, 
 " Why sitting up there close to your feet on the rug : she 
 is looking at me. .It is Kitty come here, Kitty !" 
 There were two cats in the house, one of which went by 
 this name, and they were rarely if ever in the drawing- 
 room. At this time Mrs. A. had no idea that the sight 
 of the cat was an illusion. When she was asked to touch 
 it, she got up for the purpose, and seemed as if she were 
 pursuing something which moved away. She followed a 
 few steps, and then said, " It has gone under the chair.'' 
 Mr. A. assured her it was an illusion, but she would not 
 believe it. He then lifted up the chair, and Mrs. A. saw 
 nothing more of it. The room was then searched all 
 over, and nothing found in it. There was a dog lying on 
 the hearth, who would have betrayed great uneasiness if a 
 cat had been in the room, but he lay perfectly quiet. In 
 order to be quite certain, Mr. A. rung the bell, and sent 
 for the two cats, both of which were found in the house- 
 keeper's room. 
 
 4. About a month after this occurrence, Mrs. A., who 
 had taken a somewhat fatiguing drive during the day, was 
 preparing to go to bed about eleven o'clock at night, and. 
 
SPECTRAL ILLUSIONS. 125 
 
 sitting before the dressing-glass, was occupied in arrang- 
 ing her hair. She was in a listless and drowsy state of 
 mind, but fully awake. When her fingers were in active 
 motion among the papillotes, she was suddenly startled 
 by seeing in the mirror the figure of a near relation, who 
 was then in Scotland, and in perfect health. The appa- 
 rition appeared over her left shoulder, and its eyes met 
 hers in the glass. It was enveloped in grave-clothes, 
 closely pinned, as is usual with corpses, round the head 
 and under the chin, and though the eyes were open, the 
 features were solemn and rigid. The dress was evidently 
 a shroud, as Mrs. A. remarked even the punctured pattern 
 usually worked in a peculiar manner round the edges of 
 that garment. Mrs. A. described herself a,s at the time 
 sensible of a feeling like what we conceive of fascination, 
 compelling her for a time to gaze on this melancholy 
 apparition, which was as distinct and vivid as any re- 
 flected reality could be, the light of the candles upon the 
 dressing-table appearing to shine fully upon its face. 
 After a few minutes, she turned round to look for the 
 reality of the form over her shoulder ; but it was not 
 visible, and it had also disappeared from the glass when 
 she looked again in that direction. 
 
 5. In the beginning of March, when Mr. A. had been 
 about a fortnight from home, Mrs. A. frequently heard 
 him moving near her. Nearly every night, as she lay 
 awake, she distinctly heard sounds like his breathing 
 hard on the pillow by her side, and other sounds such as 
 he might make while turning in bed. 
 
 6. On another occasion, during Mr. A.'s absence, while 
 
 riding with a neighbour, Mr. , she heard his voice 
 
 frequently as if he were riding by his side. She heard 
 also the tramp of his horse's feet, and was almost puzzled 
 by hearing him address her at the same time with the 
 person really in company. His voice made remarks on 
 
126 LETTERS ON NATURAL MAGIC. 
 
 the scenery, improvements, &c., such as he probably 
 would have done had he been present. On this occasion, 
 however, there was no visible apparition. 
 
 7. On the 17th March, Mrs. A. was preparing for bed. 
 She had dismissed her maid, and was sitting with her 
 feet in hot water. Having an excellent memory, she had 
 been thinking upon and repeating to herself a striking 
 passage in the Edinburgh Eeview, when, on raising her 
 eyes, she saw seated in a large easy-chair before her the 
 figure of a deceased friend, the sister of Mr. A. The 
 figure was dressed, as had been usual with her, with great 
 neatness, but in a gown of a peculiar kind, such as Mrs. A. 
 had never seen her wear, but exactly such as had been 
 described to her by a common friend as having been worn 
 by Mr. A.'s sister during her last visit to England. 
 Mrs. A. paid particular attention to the dress, air, and 
 appearance of the figure, which sat in an easy attitude in 
 the chair, holding a handkerchief in one hand. Mrs. A- 
 tried to speak to it, but experienced a difficulty in doing 
 so, and in about three minutes the figure disappeared. 
 About a minute afterwards, Mr. A. came into the room, 
 and found Mrs. A. slightly nervous, but fully aware of 
 the delusive nature of the apparition. She described it 
 as having all the vivid colouring and apparent reality of 
 life; and for some hours preceding this and other visions, 
 she experienced a peculiar sensation in her eyes, which 
 seemed to be relieved when the vision had ceased. 
 
 8. On the 5th October, between one and two o'clock in 
 the morning, Mr. A. was awoke by Mrs. A., who told him 
 that she had just seen the figure of his deceased mother 
 draw aside the bed- curtains and appear between them. 
 The dress and the look of the apparition were precisely 
 those in which Mr. A.'s mother had been last seen by 
 Mrs. A. at Paris in 1824. 
 
 9. On the llth October, when sitting in the drawing 
 
SPECTRAL ILLUSIONS. 127 
 
 room, on one side of the fire-place, she saw the figure of 
 another deceased friend moving towards her from the 
 window at the farther end of the room. It approached 
 the fire-place, and sat down in the chair opposite. As 
 there were several persons in the room at the time, she 
 describes the idea uppermost in her mind to have been a 
 fear lest they should be alarmed at her staring, in the way 
 she was conscious of doing, at vacancy, and should fancy 
 her intellect disordered. Under the influence of this fear, 
 and recollecting a story of a similar effect in your work 
 on Demonology, which she had lately read, she summoned 
 up the requisite^resolution to enable her to cross the space 
 before the fire-place, and seat herself in the same chair with 
 the figure. The apparition remained perfectly distinct till 
 she sat down, as it were, in its lap, when it vanished." 
 
 10. On the 26th of the same month, about two P.M., 
 Mrs. A. was sitting in a chair by the window in the same 
 room with her husband. He heard her exclaim " What 
 have I seen?" And on looking at her, he observed a 
 strange expression in her eyes and countenance. A 
 carriage and four had appeared to her to be driving up 
 the entrance road to the house. As it approached, she 
 felt inclined to go up stairs to prepare to receive com- 
 pany, but, as if spell-bound, she was unable to move or 
 speak. The carriage approached, and as it arrived within 
 a few yards of the window, she saw the figures of the 
 postilions and the persons inside take the ghastly appear- 
 ance of skeletons and other hideous figures. The whole 
 then vanished entirely, when she uttered the above- 
 mentioned exclamation. 
 
 11. On the morning of the 30th October, when Mrs. A. 
 was sitting in her own room with a favourite dog in her 
 lap, she distinctly saw the same dog moving about the 
 room d uring the space of about a minute, or rather more. 
 
 12. On the 3rd December, about 9 P.M., when Mr. and 
 
128 LETTERS ON NATURAL MAGIC. 
 
 Mrs. A. were sitting near each other in the drawing-room 
 occupied in reading, Mr. A. felt a pressure on his foot. 
 On looking up, he observed Mrs. A.'s eyes fixed with a 
 strong and unnatural stare on a chair about nine or ten 
 feet distant. Upon asking her what she saw, the expres- 
 sion of her countenance changed, and upon recovering 
 herself, she told Mr. A. that she had seen his brother, 
 who was alive and well at the moment in London, seated 
 in the opposite chair, but dressed in grave-clothes, and 
 with a ghastly countenance, as if scarcely alive. 
 
 Such is a brief account of the various spectral illusions 
 observed by Mrs. A. In describing them I have used 
 the very words employed by her husband in his communi- 
 cations to me on the subject ; * and the reader may be 
 assured that the descriptions are neither heightened by 
 fancy nor amplified by invention. The high character 
 and intelligence of the lady, and the station of her hus- 
 band in society, and as a man of learning and science, 
 would authenticate the most marvellous narrative, and 
 satisfy the most scrupulous mind, that the case has been 
 philosophically as well as faithfully described. In nar- 
 rating events which we regard as of supernatural charac- 
 ter, the mind has a strong tendency to give more promi- 
 nence to what appears to itself the most wonderful ; but 
 from the very same cause, when we describe extraordinary 
 and inexplicable phenomena which we believe to be the 
 result of natural causes, the mind is prone to strip them 
 of their most marvellous points, and bring them down to 
 the level of ordinary events. From the very commence- 
 ment of the spectral illusions seen by Mrs. A. both she 
 and her husband were well aware of their nature and 
 origin, and both of them paid the most minute attention 
 to the circumstances which accompanied them, not only 
 
 * Edinburgh Journal of Science, New Series, No. iv. p. 218, 219 ; 
 No. vi. p. 244 ; and No. viii. p. 261. 
 
SPECTRAL ILLUSIONS. 129 
 
 with the view of throwing light upon so curious a subject, 
 but for the purpose of ascertaining their connection with 
 the state of health under which they appeared. 
 
 As the spectres seen by Nicolai and others had their 
 origin in bodily indisposition, it becomes interesting to 
 learn the state of Mrs. A.'s health when she was under 
 the influence of these illusions. During the six weeks 
 within which the three first illusions took place, she had 
 been considerably reduced and weakened by a troublesome 
 cough, and the weakness which this occasioned was in- 
 creased by her being prevented from taking a daily tonic. 
 Her general health had not been strong, and long experi- 
 ence has put it beyond a doubt, that her indisposition 
 arises from a disordered state of the digestive organs. 
 Mrs. A. has naturally a morbidly sensitive imagination, 
 which so painfully affects her corporeal impressions, that 
 the account of any person having suffered severe pain by 
 accident or otherwise occasionally produces acute twinges 
 of pain in the corresponding parts of her person. The 
 account, for example, of the amputation of an arm will 
 produce an instantaneous and severe sense of pain in her 
 own arm. She is subject to talk in her sleep with great 
 fluency, to repeat long passages of poetry, particularly 
 when she is unwell, and even to cap verses for half an 
 hour together, never failing to quote lines beginning with 
 the final letter of the preceding one till her memory is 
 exhausted. 
 
 Although it is not probable that we shall ever be able 
 to understand the actual manner in which a person of 
 sound mind beholds spectral- apparitions in the broad 
 light of day, yet we may arrive at such a degree of know- 
 ledge on the subject as to satisfy rational curiosity, and to 
 strip the phenomena of every attribute of the marvellous. 
 Even the vision of natural objects presents to us insur- 
 mountable difficulties, if we seek to understand the pre- 
 
130 LETTERS ON NATURAL MAGIC. 
 
 cise part which the mind performs in perceiving them ; 
 but the philosopher considers that he has given a satisfac- 
 tory explanation of vision when he demonstrates that 
 distinct pictures of external objects are painted on the 
 retina, and that this membrane communicates with the 
 brain by means of nerves of the same substance as itself, 
 and of which it is merely an expansion. Here we reach 
 the gulf which human intelligence cannot pass ; and if 
 the presumptuous mind of man shall dare to extend its 
 speculations farther, it will do it only to evince its inca- 
 pacity and mortify its pride. 
 
 In his admirable work on this subject, Dr. Hibbert has 
 shown that spectral apparitions are nothing more than 
 ideas or the recollected images of the mind, which in 
 certain states of bodily indisposition have been rendered 
 more vivid than actual impressions, or, to use other words, 
 that the pictures in the * mind's eye " are more vivid 
 than the pictures in the body's eye. This principle has 
 been placed by Dr. Hibbert beyond the reach of doubt ; 
 but I propose to go much farther, and to show that the 
 "mind's eye" is actually the body's eye, and that the 
 retina is the common tablet on which both classes of im- 
 pressions are painted, and by means of which they receive 
 their visual existence according to the same optical laws. 
 Nor is this true merely in the case of spectral illusions. 
 It holds good of all ideas recalled by the memory or 
 created by the imagination, and may be regarded as a 
 fundamental law in the science of pneumatology. 
 
 It would be out of place in a work like this to adduce 
 the experimental evidence on which it rests, or even to 
 explain the manner in which the experiments themselves 
 must be conducted ; but I may state in general, that the 
 spectres conjured up by the memory or the fancy have 
 always a "local habitation," and that they appear in front 
 of the eye, and partake in its movements exactly like the 
 
PICTURES ON THE RETINA. 131 
 
 impressions of luminous objects after the objects them- 
 selves are withdrawn. 
 
 In the healthy state of the mind and body, the relative 
 intensity of these two classes of impressions on the retina 
 are nicely adjusted. The mental pictures are transient 
 and comparatively feeble, and in ordinary temperaments 
 are never capable of disturbing or effacing the direct 
 images of visible objects. The affairs of life could not be 
 carried on if the memory were to intrude bright repre- 
 sentations of the past into the domestic scene, or scatter 
 them over the external landscape. The two opposite 
 impressions, indeed, could not coexist : the same nervous 
 fibre which is carrying from the brain to the retina the 
 figures of memory, could not at the same instant be carry- 
 ing back the impressions of external objects from the 
 retina to the brain. The mind cannot perform two 
 different functions at the same instant, and the direction 
 of its attention to one of the two classes of impressions 
 necessarily produce the extinction of the other : but so 
 rapid is the exercise of mental pawer, that the alternate 
 appearance and disappearance of the two contending 
 impressions is no more recognized than the successive 
 observations of external objects during the twinkling of 
 the eyelids. If we look, for example, at the facade of 
 St. Paul's, and, without changing our position, call to 
 mind the celebrated view of Mont Blanc from Lyons, the 
 picture of the cathedral, though actually impressed upon 
 the retina, is momentarily lost sight of by the mind, 
 exactly like an object seen by indirect vision ; and during 
 the instant the recollected image of the mountain, tower- 
 ing over the subjacent range, is distinctly seen, but in a 
 tone of subdued colouring, and indistinct outline. When 
 the purpose of its recall is answered, it quickly disappears, 
 and the picture of the cathedral again resumes the ascen- 
 dency. 
 
132 LETTERS ON NATURAL MAGIC. 
 
 In darkness and solitude, when external objects no 
 longer interfere with the pictures of the mind, they be- 
 come more vivid and distinct ; and in the state between 
 waking and sleeping, the intensity of the impressions 
 approaches to that of visible objects. With persons of 
 studious habits, who are much occupied with the operations 
 of their own minds, the mental pictures are much more 
 distinct than in ordinary persons ; and in the midst of 
 abstract thought, external objects even cease to make any 
 impression on the retina. A philosopher absorbed in his 
 contemplations experiences a temporary privation of the 
 use of his senses. His children or his servants will enter 
 the room directly before his eyes without being seen. 
 They will speak to him without being heard ; and they 
 will even try to rouse him from his reverie without being 
 felt ; although his eyes, his ears, and his nerves, actually 
 receive the impressions of light, sound, and touch. In 
 such cases, however, the philosopher is voluntarily pursu- 
 ing a train of thought on which his mind is deeply in- 
 terested; but even ordinary men, not much addicted to 
 speculations of any kind, often perceive in their mind's 
 eye the pictures of deceased or absent friends, or even 
 ludicrous creations of fancy, which have no connection 
 whatever with the train of their thoughts. Like spectral 
 apparitions, they are entirely involuntary, and though 
 they may have sprung from a regular series of associa- 
 tions, yet it is frequently impossible to discover a single 
 link in the chain. 
 
 If it be true, then, that the pictures of the mind and 
 spectral illusions are equally impressions upon the retina, 
 the latter will differ in no respect from the former, but in 
 the degree of vividness with which they are seen ; and 
 those frightful apparitions become nothing more than our 
 ordinary ideas, rendered more brilliant by some accidental 
 and temporary derangement of the vital functions. Their 
 
GENERAL VIEWS. 133 
 
 very vividness too, which is their only characteristic, is 
 capable of explanation. I have already shown that the 
 retina is rendered more sensible to light by voluntary 
 local pressure, as well as by the involuntary pressure of 
 the blood-vessels behind it; and if, by looking at the 
 sun, we impress upon the retina a coloured image of that 
 luminary, which is seen even when the eye is shut, we 
 may by pressure alter the colour of that image, in con- 
 sequence of having increased the sensibility of that part 
 of the retina on which it is impressed. Hence we may 
 readily understand how the vividness of the mental 
 pictures must be increased by analogous causes. 
 
 In the case both of Nicolai and Mrs. A. the immediate 
 cause of the spectres was a deranged action of the 
 stomach. When such a derangement is induced by poison, 
 or by substances which act as poisons, the retina is 
 peculiarly affected, and the phenomena of vision singularly 
 changed. Dr. Patouillet has described the case of a 
 family of nine persons who were all driven mad by eating 
 the root of the Hyoscyamus niger, or black Henbane. One 
 of them leapt into a pond. Another exclaimed that his 
 neighbour would lose a cow in a month, and a third 
 vociferated that the crown piece of sixty pence would in 
 a short time rise to five livres. On the following day 
 they had all recovered their senses, but recollected nothing 
 of what had happened. On the same day they all saw 
 objects double, and, what is still more remarkable, on the 
 third day every object appeared to them as red as scarlet. 
 Now this red light was probably nothing more than the 
 red phosphorescence produced by the pressure of the 
 blood-vessels on the retina, and analogous to the masses of 
 blue, green, yellow, and red light, which have been already 
 mentioned as produced by a similar pressure in headaches, 
 arising from a disordered state of the digestive organs. 
 
 Were we to analyse the various phenomena of spectral 
 
134 LETTERS ON NATURAL MAGIC. 
 
 illusions, we should discover many circumstances favour- 
 able to these views. In those seen by Nicolai the in- 
 dividual figures were always somewhat paler than natural 
 objects. They sometimes grew more and more indistinct, 
 and became perfectly white ; and, to use his own words, 
 " he could always distinguish, with the greatest precision, 
 phantasms from phenomena." Nicolai sometimes saw the 
 spectres when his eyes were shut, and sometime^ they 
 were thus made to disappear, effects perfectly identical 
 with those which arise from the impressions of very 
 luminous objects. Sometimes the figures vanished en- 
 tirely, and at other times only pieces of them disappeared, 
 exactly conformable to what takes place with objects seen 
 by indirect vision, which most of those figures must 
 necessarily have been. 
 
 Among the peculiarities of spectral illusions there is 
 one which merits particular attention, namely, that they 
 seem to cover or conceal objects immediately beyond them. 
 It is this circumstance more than any other which gives 
 them the character of reality, and at first sight it seems 
 difficult of explanation. The distinctness of any impres- 
 sion on the retina is entirely independent of the accommo- 
 dation of the eye to the distinct vision of external objects. 
 When the eye is at rest, and is not accommodated to 
 objects at any particular distance, it is in a state for 
 seeing distant objects most perfectly. When a distinct 
 spectral impression, therefore, is before it, all other objects 
 in its vicinity will be seen indistinctly, for while the eye 
 is engrossed with the vision, it is not likely to accommo- 
 date itself to any other object in the same direction. It 
 is quite common, too, for the eye to see only one of two 
 objects actually presented to it. A sportsman who has 
 been in the practice of shooting with both his eyes open 
 actually sees a double image of the muzzle of his fowling- 
 piece, though it is only with one of these images that he 
 
GENERAL VIEWS. 135 
 
 covers his game, having no perception whatever of the 
 other. But there is still another principle upon which 
 only one of two objects may be seen at a time. If we 
 look veryj steadily and continuously at a double pattern, 
 such as those on a carpet composed of two single patterns 
 of different colours, suppose red and yellow ; and if we 
 direct the mind particularly to the contemplation of the 
 red one, the green pattern will sometimes vanish entirely, 
 leaving the red one alone visible, and by the same process 
 the red one may be made to disappear. In this case, 
 however, the two patterns, like the two images, may be 
 seen together ; but if the very same portion of the retina 
 is excited by the direct rays of an external object, when 
 it is excited by a mental impression, it can no more see 
 them both at the same time than a vibrating string can 
 give out two different fundamental sounds. It is quite pos- 
 sible, however, that the brightest parts of a spectral figure 
 may be distinctly seen along with the brightest parts of 
 an object immediately behind it, but then the bright parts 
 of each object will fall upon different parts of the retina. 
 
 These views are illustrated by a- case mentioned by 
 Dr. Abercrombie. A gentleman, who was a patient of 
 his, of an irritable habit, and liable to a variety of uneasy 
 sensations in his head, was sitting alone in his dining- 
 room in the twilight, when the door of the room was a 
 little open. He saw distinctly a female figure enter, 
 wrapped in a mantle, with the face concealed by a large 
 black bonnet. She seemed to advance a few steps towards 
 him, and then stop. He had a full conviction that the 
 figure was an illusion of vision, and he amused himself 
 for some time by watching it ; at the same time observing 
 that he could see through the figure so as to perceive the 
 lock of the door, and other objects behind it.* 
 
 * Inquiries concerning the Intellectual Powers, and the Investi- 
 gation of Truth. 
 
136 
 
 LETTERS ON NATURAL MAGIC. 
 
 If these views be correct the phenomena of spectral 
 apparitions are stripped of all their terror, whether we 
 view them in their supernatural character or as indications 
 of bodily indisposition. Nicolai, even, in whose case 
 they were accompanied with alarming symptoms, derived 
 pleasure from the contemplation of them, and he not only 
 recovered from the complaint in which they originated, 
 but survived them for many years. Mrs. A., too, who 
 sees them only at distant intervals, and with whom they 
 have but a fleeting existence, will, we trust, soon lose her 
 exclusive privilege, when the slight indisposition which 
 gives them birth has subsided. 
 
SCIENCK USED AS AN INSTRUMENT OF IMPOSTURE. 137 
 
 LETTER IV. 
 
 Science used as an instrument of imposture Deceptions with plane 
 and concave mirrors practised by the ancients The magician's 
 mirror Effects of concave mirrors Aerial Images Images on 
 smoke Combination of mirrors for producing pictures from 
 living objects The mysterious dagger Ancient miracles with 
 concave mirrors Modern necromancy with them, as seen by 
 Cellini Description and effects of the magic lantern Improve- 
 ments upon it Phantasmagoric exhibitions of Philipstal and 
 others Dr. Young's arrangement of Lenses, &c., for the Phan- 
 tasmagoria Improvements suggested Catadioptrical phantas- 
 magoria for producing the pictures from living objects Method 
 of cutting off parts of the figures Kircher's mysterious hand- 
 writing on the wall His holloiv cylindrical mirror for aerial 
 images Cylindrical mirror for reforming distorted pictures 
 Mirrors of variable curvature for producing caricatures. 
 
 IN the preceding observations man appears as the victim 
 of his own delusions as the magician unable to exorcise 
 the spirits which he has himself called into being. We 
 shall now see him the dupe of preconcerted imposture 
 the slave of his own ignorance the prostrate vassal of 
 power and superstition. I have already stated that the 
 monarchs and priests of ancient times carried on a sys- 
 tematic plan of imposing upon their subjects a mode of 
 government which was in perfect accordance with their 
 religious belief : but it will scarcely be believed that the 
 same delusions w^ere practised after the establishment of 
 Christianity, and that even the Catholic sanctuary was 
 often the seat of these unhallowed machinations. Nor 
 was it merely the low and cunning priest who thus sought 
 to extort money and respect from the most ignorant of his 
 
 L 
 
138 LETTEKS ON NATURAL MAGIC. 
 
 flock : bishops and pontiffs themselves wielded the magi- 
 cian's wand over the diadems of kings and emperors, anrL 
 by the pretended exhibition of supernatural power, made 
 the mightiest potentates of Europe tremble upon their 
 thrones. It was the light of science alone which dispelled 
 this moral and intellectual darkness, and it is entirely in 
 consequence of its wide diffusion that we live in times 
 when sovereigns seek to reign only through the affections 
 of their people, and when the minister of religion asks no 
 other reverence but that which is inspired by the sanctity 
 of his office and the purity of his character. 
 
 It was fortunate for the human race that the scanty 
 knowledge of former ages afforded so few elements of 
 deception. What a tremendous engine would have been 
 worked against our species by the varied and powerful 
 machinery of modern science! Man would still have 
 worn the shackles which it forged, and his noble spirit 
 would still have groaned beneath its fatal pressure. 
 
 There can be little doubt that the most common, as 
 well as the most successful, impositions of the ancients 
 were of an optical nature, and were practised by means of 
 plane and concave mirrors. It has been clearly shown by 
 various writers that the ancients made use of mirrors of 
 steel, silver, and a composition of copper and tin, like 
 those now used for reflecting specula. It is also very 
 probable from a passage in Pliny, that glass mirrors were 
 made at Sidon ; but it is evident that, unless the object 
 presented to them was illuminated in a very high degree, 
 the images which they formed must have been very faint 
 and unsatisfactory. The silver mirrors, therefore, which 
 were universally used, and which are superior to those 
 made of any other metal, are likely to have been most 
 generally .J employed by the ancient magicians. They 
 were made to give multiplied and inverted images of 
 objects, that is, they were plane, polygonal or many- 
 
MAGICIAN'S MIRROR. 139 
 
 sided, and concave. There is one property, however, 
 mentioned by Aulus Gellius, which has given unnecessary 
 perplexity to commentators. He states that there were 
 specula which, when put in a particular place, gave no 
 images of objects, but, when carried to another place, 
 recovered their property of reflection.* M. Salverte is of 
 opinion that, in quoting Varro, Aulus Gellius was not 
 sufficiently acquainted with the subject, and erred in 
 supposing that the phenomenon depended on the place 
 instead of the position of the mirror ; but this criticism is 
 obviously made with the view of supporting an opinion of 
 his own, that the property in question may be analogous 
 to the phenomenon of polarised light, which at a certain 
 angle refuses to suffer reflection from particular bodies. 
 If this idea has any foundation, the mirror must have been 
 of glass or some other body not metallic, or, to speak 
 more correctly, there must have been two such mirrors, so 
 nicely adjusted not only to one another, but to the light 
 incident upon each, that the effect could not possibly be 
 produced but by a philosopher thoroughly acquainted 
 with the modern discovery of the polarisation of light by 
 reflection. Without seeking for so profound an explana- 
 tion of the phenomenon, we may readily understand how 
 a silver mirror may instantly lose its reflecting power, in 
 a damp atmosphere, in consequence of the precipitation of 
 moisture upon its surface, and may immediately recover it 
 when transported into drier air. 
 
 One of the simplest instruments of optical deception is 
 the plane mirror, and when two are combined for this 
 purpose it has been called the magician's mirror. An 
 observer in front of a plane mirror sees a distinct image 
 of himself ; but if two persons take up a mirror, and if 
 the one person is as much to one side of a line perpen- 
 
 * Ut speculum in loco certo positum nihil imagf.net ; aliorsum trant- 
 latumfadat imagines. Aul. Gel. Noct. Attic, lib. xvi. cap. 18. 
 
140 
 
 LETTEllS ON NATURAL MAGIC. 
 
 dicular to the middle of it as the other is to the other side, 
 they will see each other but not themselves. If we now 
 suppose M C, C D, N C, C D to be the partitions of two 
 adjacent apartments, let square openings be made in the 
 partitions at A and B, about five feet above the floor, and 
 let them be filled with plate glass, and surrounded with a 
 picture frame, so as to have the appearance of two mirrors. 
 Place two mirrors E, F, one behind each opening at A 
 and B, inclined 45 to the partition M N, and so large 
 that a person looking into the plates of glass at A and B 
 will not see their edges. When this is done it is obvious 
 
 Fig. 3. 
 
 that a person looking into the mirror A will not see him- 
 self but will see any person or figure placed at B. If he 
 believes that he is looking into a common mirror at A, 
 his astonishment will be great at seeing himself trans- 
 formed into another person, or into any living animal 
 that may be placed at B. The success of this deception 
 would be greatly increased if a plane mirror suspended 
 by a pulley could be brought immediately behind the 
 plane glass at A, and drawn up from it at pleasure. The 
 spectator at A having previously seen himself in this 
 moveable mirror, would be still more astonished when he 
 afterwards perceived in the same place a face different 
 
CONCAVE MIRRORS. 141 
 
 from liis own. By drawing the moveable mirror half up, 
 the spectator at A might see half of his own face joined 
 to half of the face placed at B ; but in the present day the 
 most ignorant persons are so familiar with the properties 
 of a looking-glass that it would be very difficult to employ 
 this kind of deception with the same success which must 
 have attended it in a more illiterate age. The optical 
 reader will easily see that the mirror F and the apartment 
 N C D are not absolutely necessary for carrying on this 
 deception ; for the very same effects will be produced if 
 the person at B is stationed at G, and looks towards the 
 mirror F in the direction G F. As the mirror F, however, 
 must be placed as near to A as possible, the person at G 
 would be too near the partition C N, unless the mirror F 
 was extremely large. 
 
 The effect of this and every similar deception is greatly 
 increased when the persons are illuminated with a strong 
 light, and the rest of the apartment as dark as possible ; 
 but whatever precautions are taken, and however skilfully 
 plane mirrors are combined, it is not easy to produce 
 with them any very successful illusions. 
 
 The concave mirror is the staple instrument of the 
 magician's cabinet, and must always perform a principal 
 part in all optical combinations. In order to be quite 
 perfect, every concave mirror should have its surface 
 elliptical, so that if any object is placed in one focus of 
 the ellipse, an inverted image of it will be formed in the 
 other focus. This image, to a spectator rightly placed, 
 appears suspended in the air, so that if the mirror and 
 the object are hid from his view, the effect must appear to 
 him almost supernatural. 
 
 The method of exhibiting the effect of concave mirrors 
 most advantageously is shown in Fig. 3, where C D is the 
 partition of a room having in it a square opening E F, the 
 centre of which is about five feet above the floor. This 
 
142 
 
 LETTERS ON NATURAL MAGIC. 
 
 opening might be surrounded with a picture-frame, and a 
 painting which exactly filled it might be so connected 
 with a pulley that it could be either slipped aside, or 
 raised so as to leave the frame empty. A large concave 
 mirror M N is then placed in another apartment, so that 
 when any object is placed at A, a distinct image of it 
 may be formed in the centre of the opening E F . Let us 
 suppose this object to be a plaster cast of any object made 
 as white as possible, and placed in an inverted position at 
 A. A strong light should then be thrown upon it by a 
 
 Fig. 4. 
 
 powerful lamp, the rays of which are prevented from 
 reaching the opening E F. When this is done, a spectator 
 placed at will see an erect image of the statue at B the 
 centre of the opening standing in the air, and differing 
 from the real statue only in being a little larger, while 
 the apparition will be wholly invisible to other spectators 
 placed at a little distance on each side of him. t 
 
 If the opening E F is filled with smoke rising either 
 from a chafing dish, in which incense is burnt, or made to 
 issue in clouds from some opening below, the image will 
 appear in the middle of the smoke depicted upon it as 
 upon a ground, and capable of being seen by those 
 spectators who could not see the image in the air. The 
 
MYSTERIOUS DAGGER. 143 
 
 rays of light, in place of proceeding without obstruction 
 to an eye at 0, are reflected as it were from those minute 
 particles of which the smoke is composed, in the same 
 manner as a beam of light is rendered more visible by 
 passing through an apartment filled with dust or smoke. 
 
 It has long been a favourite experiment to place at A, 
 a white and strongly-illuminated human skull, and, to 
 exhibit an image of it amid the smoke of a chafing dish 
 at B ; but a more terrific effect would be produced if a 
 small skeleton, suspended by invisible wires, were placed 
 as an object at A. Its image suspended in the air at B, 
 or painted upon smoke, could not fail to astonish the 
 spectator. 
 
 The difficulty of placing a living person in an inverted 
 position, as an object at A, has no doubt prevented the 
 optical conjurer from availing himself of so admirable a 
 resource ; but this difficulty may be removed by employing 
 a second concave mirror. This second mirror must be so 
 placed as to reflect towards M N, the rays proceeding from 
 an erect living object, and to form an inverted image of 
 this object at A. An erect image of this inverted image 
 will then be formed at B, either suspended in the air or 
 depicted upon a wreath of smoke. This aerial image will 
 exhibit the precise form and colours and movements of 
 the living object, and it will maintain its character as an 
 apparition if any attempt is made by the spectator to 
 grasp its unsubstantial fabric. 
 
 A deception of an alarming kind, called the Mysterious 
 dagger, has been long a favourite exhibition. If a person 
 with a drawn and highly-polished dagger, illuminated by 
 a strong light, stands a little farther from a concave 
 mirror than its principal focus, he will perceive in the air, 
 between himself and the mirror, an inverted and di- 
 minished image of his own person with the dagger 
 similarly brandished : if he aims the dagger at the centre 
 
144 LETTERS ON NATURAL MAGIC. 
 
 of the mirror's concavity, the two daggers will meet point 
 to point, and, by pushing it still farther from him towards 
 the mirror, the imaginary dagger will strike at his heart. 
 In this case it is necessary that the direction of the real 
 dagger coincides with a diameter of the sphere of which 
 the mirror is a part ; but if its direction is on one side of 
 that diameter, the direction of the imaginary dagger will 
 be as far on the other side of the diameter, and the latter 
 will aim a blow at any person who is placed in the proper 
 position for receiving it. If the person who bears the 
 real dagger is therefore placed behind a screen, or other- 
 wise concealed from the view of the spectator who is 
 made to approach to the place of the image, the thrust of 
 the polished steel at his breast will not fail to produce a 
 powerful impression. The effect of this experiment would 
 no doubt be increased by covering with black cloth the 
 person who holds the dagger, so that the image of his 
 hand only should be seen, as the inverted picture of him 
 would take away from the, reality of the appearance. By 
 using two mirrors, indeed, this defect might be remedied, 
 and the spectator would witness an exact image of the 
 assassin aiming the dagger at his life. 
 
 The common way of making this experiment is to place 
 a basket of fruit above the dagger, so that a distinct aerial 
 image of the fruit is formed in the focus of the mirror. 
 The spectator having been desired to take some fruit from 
 the basket, approaches for that purpose, while a person 
 properly concealed withdraws the real basket of fruit 
 with one hand, and with the other advances the dagger, 
 the image of which, being no longer covered by the fruit, 
 strikes at the body of the astonished spectator. 
 
 The powers of the concave mirror have been likewise 
 displayed in exhibiting the apparition of an absent or 
 deceased friend. For this purpose a strongly-illuminated 
 bust or picture of the person is placed before the concave 
 
CONCAVE MIRRORS. 145 
 
 mirror, and a distinct image of the picture will be seen 
 either in the air or among smoke in the manner already 
 described. If the background of the picture is tempo- 
 rarily covered with lamp-black, so that there is no light 
 about the picture but what falls upon the figure, the 
 effect will be more complete. 
 
 As in all experiments with concave mirrors the size 
 of the aerial image is to that of the real object as their 
 distances from the mirror, we may, by varying the dis- 
 tance of the object, increase or diminish the size of the 
 image. In doing this, however, the distance of the 
 image from the mirror is at the same time changed, so 
 that it would quit the place most suitable for its exhibition. 
 This defect may be removed by simultaneously changing 
 the place both of the mirror and the object, so that the image 
 may remain stationary, expanding itself from a luminous 
 spot to a gigantic size, and again passing through all inter- 
 mediate magnitudes, till it vanishes in a cloud of light. 
 
 Those who have studied the effects of concave mirrors 
 of a small size, and without the precautions necessary to 
 insure deception, cannot form any idea of the magical 
 effect produced by this class of optical apparitions. 
 When the instruments of illusion are themselves con- 
 cealed when all extraneous lights but those which 
 illuminate the real object are excluded when the mirrors 
 are large and well polished and truly formed the effect 
 of the representation on ignorant minds is altogether 
 overpowering, while even those who know the deception, 
 and perfectly understand its principles, are not a little 
 surprised at its effects. The inferiority in the effects of 
 a common concave mirror to that of a well-arranged 
 exhibition, is greater even than that of a perspective 
 picture hanging in an apartment to the same picture 
 exhibited under all the imposing accompaniments of a 
 dioramic representation. 
 
146 LETTERS ON NATURAL MAGIC. 
 
 It can scarcely be doubted, that a concave mirror was 
 the principal instrument by which the heathen gods were 
 made to appear in the ancient temples. In the imperfect 
 accounts which have reached us of these apparitions, we 
 can trace all the elements of an optical illusion. In the 
 ancient temple of Hercules at Tyre, Pliny mentions that 
 there was a seat made of a consecrated stone, "from 
 which the gods easily rose." Esculapius often exhibited 
 himself to his worshippers in his temple at Tarsus ; and 
 the temple of Enguinum in Sicily was celebrated as the 
 place where the goddesses exhibited themselves to mortals. 
 Jamblichus actually informs us that the ancient magicians 
 caused the gods to appear among the vapours disengaged 
 from fire ; and when the conjurer Maximus terrified his 
 audience by making the statue of Hecate laugh, while in 
 the middle of the smoke of burning incense, he was 
 obviously dealing with the image of a living object 
 dressed in the costume of the sorceress. 
 
 The character of these exhibitions in the ancient 
 temples is so admirably depicted in the following passage 
 of Damascius quoted by M. Salverte, that we recognize 
 all the optical effects which have been already described. 
 " In a manifestation," says he, " which ought not to be 
 revealed .... there appeared on the wall of the temple 
 a mass of light which at first seemed to be very remote ; 
 it transformed itself in coming nearer, into a face evi- 
 dently divine and supernatural, of a severe aspect, but 
 mixed with gentleness, and extremely beautiful. Accord- 
 ing to the institutions of a mysterious religion the Alex- 
 andrians honoured it as Osiris and Adonis." 
 
 Among more modern examples of this illusion, we may 
 mention the case of the Emperor Basil of Macedonia. 
 Inconsolable at the loss of his son, this sovereign had 
 recourse to the prayers of the Pontiff Theodore Santa- 
 baren, who was celebrated for his power of working 
 
MODERN NECROMANCY. 147 
 
 miracles. The ecclesiastical conjurer exhibited to him 
 the image of his beloved son magnificently dressed and 
 mounted upon a superb charger : the youth rushed 
 towards his father, threw himself into his arms, and 
 disappeared. M. Salverte judiciously observes, that this 
 deception could not have been performed by a real 
 person who imitated the figure of the young prince. 
 The existence of this person, betrayed by so remarkable 
 a resemblance, and by the trick of the exhibition, could 
 not fail to have been discovered and denounced, even if 
 we could explain how the son could be so instantaneously 
 disentangled from his father's embrace. The emperor, 
 in short, saw the aerial image of a picture of his son on 
 horseback, and as the picture was brought nearer the 
 mirror, the image advanced into his arms, when it of 
 course eluded his affectionate grasp. 
 
 These and other allusions to the operations of the 
 ancient magic, though sufficiently indicative of the 
 methods which were employed, are too meagre to convey 
 any idea of the splendid and imposing exhibitions which 
 must have been displayed. A national system of decep- 
 tion, intended as an instrument of government, must have 
 brought into requisition not merely the scientific skill of 
 the age, but a variety of subsidiary contrivances, cal- 
 culated to astonish the beholder, to confound his judg- 
 ment, to dazzle his senses, and to give a predominant 
 influence to the peculiar imposture which it was thought 
 desirable to establish. The grandeur of the means may 
 be inferred from their efficacy, and from the extent of 
 their influence. 
 
 This defect, however, is to a certain degree supplied 
 by an account of a modern necromancy, which has been 
 left us by the celebrated Benvenuto Cellini, and in which 
 he himself performed an active part. 
 
 "It happened," says he, "through a variety of odd 
 
148 LETTERS ON NATURAL MAGIC. 
 
 accidents, that I made acquaintance with a Sicilian priest, 
 who was a man of genius, and well versed in the Latin 
 and Greek authors. Happening one day to have some 
 conversation with him when the subject turned upon the 
 art of necromancy, I, who had a great desire to know 
 something of the matter, told him that I had all my life 
 felt a curiosity to be acquainted with the mysteries of 
 this art. 
 
 " The priest made answer, * That the man must be of a 
 resolute and steady temper who enters upon that study.' 
 T replied, ' That I had fortitude and resolution enough, if 
 I could but find an opportunity.' The priest subjoined, 
 * If you think you have the heart to venture, I will give 
 you all the satisfaction you can desire.' Thus we agreed 
 to enter upon a plan of necromancy. The priest one 
 evening prepared to satisfy me, and desired me to look 
 out for a companion or two. I invited one Vincenzio 
 Romoli, who was my intimate acquaintance : he brought 
 with him a native of Pistoia, who cultivated the black 
 art himself. We repaired to the Colosseo, and the priest, 
 according to the custom of necromancers, began to draw 
 circles upon the ground, with the most impressive cere- 
 monies imaginable : he likewise brought hither assa- 
 fcetida, several precious perfumes, and fire, with some 
 compositions also, which diffused noisome odours. As 
 soon as he was in readiness, he made an opening to the 
 circle, and having taken us by the hand, ordered the 
 other necromancer, his partner, to throw the perfumes 
 into the fire at a proper time, intrusting the care of the 
 fire and perfumes to the rest ; and thus he began his 
 incantations. This ceremony lasted above an hour and 
 a half, when there appeared several legions of devils, 
 insomuch that the amphitheatre was quite filled with them. 
 I was busy about the perfumes, when the priest, perceiv- 
 ing there was a considerable number of infernal spirits, 
 
MODERN NECROMANCY. 149 
 
 turned to me and said, ' Benvenuto, ask them something ?' 
 I answered, ' Let them bring me into the company of my 
 Sicilian mistress Angelica.' That night he obtained no 
 answer of any sort ; but I had received great satisfaction 
 in having my curiosity so far indulged. The necromancer 
 told me it was requisite we should go a second time, 
 assuring me that I should be satisfied in whatever I asked ; 
 but that I must bring with me a pure immaculate boy. 
 
 " I took with me a youth who was in my service, of 
 about twelve years of age, together with the same Vin- 
 cenzio Eomoli, who had been my companion the first 
 time, and one Agnolino Gaddi, an intimate acquaintance, 
 whom I likewise prevailed on to assist at the ceremony. 
 When we came to the place appointed, the priest having 
 made his preparations as before, with the same and even 
 more striking ceremonies, placed us within the circle, 
 which he had likewise drawn with a more wonderful art, 
 and in a more solemn manner, than at our former meeting. 
 Thus, having committed the care of the perfumes and the 
 fire to my friend Vincenzio, who was assisted by Agnolino 
 Gaddi, he put into my hand a pintaculo or magical chart, 
 and bid me turn it towards the places that he should 
 direct me ; and under the pintaculo I held the boy. The 
 necromancer, having begun to make his tremendous in- 
 vocations, called by their names a multitude of demons 
 who were the leaders of the several legions, and ques- 
 tioned them, by the power of the eternal uncreated God, 
 who lives for ever, in the Hebrew language, as likewise 
 in Latin and Greek; insomuch that the amphitheatre 
 was almost in an instant filled with demons more 
 numerous than at the former conjuration. Vincenzio 
 Romoli was busied in making a fire, with the assistance 
 of Agnolino, and burning a great ' quantity of precious 
 perfumes. I, by the directions of the necromancer, again 
 desired to be in the company of my Angelica. The 
 
150 LETTERS ON NATURAL MAGIC. 
 
 former thereupon turning to me, said, * Know, they have 
 declared that in the space of a month you shall be in her 
 company.' 
 
 " He thus requested me to stand resolutely by him, 
 because the legions were now above a thousand more in 
 number than he had designed ; and besides, these were 
 the most dangerous ; so that, after they had answered my 
 question, it behoved him to be civil to them and dismiss 
 them quietly. At the same time the boy under the 
 pintaculo was in a terrible fright, saying that there were 
 in that place a million of fierce men, who threatened to 
 destroy us ; and that, moreover, four armed giants of 
 enormous stature were endeavouring to break into our 
 circle. During this time, whilst the necromancer, 
 trembling with fear, endeavoured by mild and gentle 
 methods to dismiss them in the best way he could, 
 Vincenzio Eomoli, who quivered like an aspen leaf, took 
 care of the perfumes. Though I was as much terrified 
 as any of them, I did my utmost to conceal the terror 
 I felt ; so that I greatly contributed to inspire the rest 
 with resolution ; but the truth is, I gave myself over for 
 a dead man, seeing the horrid fright the necromancer was 
 in. The boy placed his head between his knees and said, 
 ' In this posture will I die ; for we shall all surely perish.' 
 I told him that all these demons were under us, and what 
 he saw was smoke and shadow ; so bid him hold up his 
 head and take courage. No sooner did he look up than 
 he cried out, ' The whole amphitheatre is burning, and 
 the fire is just falling upon us.' So covering his eyes 
 with his hands, he again exclaimed, ' That destruction 
 was inevitable, and desired to see no more.' The necro- 
 mancer entreated me to have a good heart, and take care 
 to burn proper perfumes ; upon which I turned to Romoli, 
 and bid him burn all the most precious perfumes he had. 
 At the same time I cast my eye upon Agnolino Gaddi, 
 
MODERN NECROMANCY. 151 
 
 who was terrified to such a degree that he could scarce 
 distinguish objects, and seemed to be half-dead. Seeing 
 him in this condition, I said, ' Agnolino, upon these 
 occasions a man should not yield to fear, but should 
 stir about and give his assistance, so come directly and 
 put on some more of these.' The effects of poor Agno- 
 lino's fear were overpowering. The boy hearing a crepi- 
 tation ventured once more to raise his head, when, seeing 
 me laugh, he began to take courage, and said ' That the 
 devils were flying away with a vengeance.' 
 
 "In this condition we stayed till the bell rung for 
 morning prayers. The boy again told us, that there 
 remained but few devils, and these were at a great 
 distance. When the magician had performed the rest of 
 his ceremonies, he stripped off his gown, and took up 
 a wallet full of books which he had brought with him. 
 
 " We all went out of the circle together, keeping as 
 close to each other as we possibly could, especially the 
 boy, who had placed himself in the middle, holding the 
 necromancer by the coat, and me by the cloak. As we 
 were going to our houses in the quarter of Banchi, the 
 boy told us that two of the demons whom we had seen at 
 the amphitheatre went on before us leaping and skipping, 
 sometimes running upon the roofs of the houses, and 
 sometimes upon the ground. The priest declared, that 
 though he had often entered magic circles, nothing so 
 extraordinary had ever happened to him. As we went 
 along, he would fain persuade me to assist with him at 
 consecrating a brook from which, he said, we should 
 derive immense riches : we should then ask the demons 
 to discover to us the various treasures with which the 
 earth ajbounds, which would raise us to opulence and 
 power ; but that these love-affairs were mere follies, from 
 whence no good could be expected. I answered, ' That 
 I would readily have accepted his proposal, if I under- 
 
152 LETTERS ON NATURAL MAGIC. 
 
 stood Latin.' He redoubled his persuasions, assuring me 
 that the knowledge of the Latin language was by no 
 means material. He added, that he could have Latin 
 scholars enough, if he had thought it worth while to look 
 out for them, but that he could never have met with a 
 partner of resolution and intrepidity equal to mine, and 
 that I should by all means follow his advice. Whilst we 
 were engaged in this conversation, we arrived at our re- 
 spective houses, and all that night dreamt of nothing but 
 devils." 
 
 It is impossible to peruse the preceding description 
 without being satisfied that the legions of devils were not 
 produced by any influence upon the imaginations of the 
 spectators, but were actual optical phantasms, or the 
 images of pictures or objects produced by one or more 
 concave mirrors or lenses. A fire is lighted, and perfumes 
 and incense are burnt, in order to create a ground for the 
 images, and the beholders are rigidly confined within the 
 pale of the magic circle. The concave mirror and the 
 objects presented to it having been so placed that the 
 persons within the circle could not see the aerial image 
 of the objects by the rays directly reflected from the 
 mirror, the work of deception was ready to begin. The 
 attendance of the magician upon his mirror was by no 
 means necessary. He took his place along with the spec- 
 tators within the magic circle. The images of the devils 
 were all distinctly formed in the air immediately above 
 the fire, but none of them could be seen by those within 
 the circle. The moment, however, that perfumes were 
 thrown into the fire to produce smoke, the first wreath of 
 smoke that rose through the place of one or more of the 
 images would reflect them to the eyes of the spectator, 
 and they could again disappear if the wreath was not 
 followed by another. More and more images would be 
 rendered visible as new wreaths of smoke arose, and the 
 
MODERN NECROMANCY. 153 
 
 whole group would appear at once when the smoke was 
 uniformly diffused over the place occupied by the images. 
 
 The " compositions which diffused noisome odours " 
 were intended to intoxicate or stupify the spectators, so 
 as to increase their liability to deception, or to add to 
 the real phantasms which were before their eyes others 
 which were the offspring only of their own imaginations. 
 It is not easy to gather from the description what parts 
 of the exhibition were actually presented to the eyes of 
 the spectators, and what parts of it were imagined by 
 themselves. It is quite evident that the boy, as well as 
 Agnolino Gaddi, were so overpowered with terror that 
 they fancied many things which they did not see ; but 
 when the boy declares that four armed giants of an enor- 
 mous stature were threatening to break into their circle, 
 he gives an accurate description of the effect that would 
 be produced by pushing the figures nearer the mirror, 
 and then magnifying their images, and causing them to 
 advance towards the circle. Although Cellini declares 
 that he was trembling with fear, yet it is quite evident 
 that he was not entirely ignorant of the machinery which 
 was at work, for in order to encourage the boy, who was 
 almost dead with fear, he assured them that the devils 
 were under their power, and that " what he saw was 
 smoke and shadow." 
 
 Mr. Roscoe, from whose Life of Cellini the preceding 
 description is taken, draws a similar conclusion from the 
 consolatory words addressed to the boy, and states that 
 they " confirm him in the belief, that the whole of these 
 appearances, like a phantasmagoria, were merely the 
 effects of a magic lantern produced on volumes of smoke 
 from various kinds of burning wood." In drawing this 
 conclusion, Mr. Roscoe has not adverted to the fact, that 
 this exhibition took place about the middle of the sixteenth 
 century, while the magic lantern was not invented by 
 
 M 
 
154 LETTERS ON NATURAL MAGIC. 
 
 Kircher till towards the middle of the seventeenth century, 
 Cellini having died in 1570, and Kircher having been 
 born in 1601. There is no doubt that the effects described 
 could be produced by this instrument, but we are not 
 entitled to have recourse to any other means of explana- 
 tion but those which were known to exist at the time of 
 Cellini. If we suppose, however, that the necromancer 
 either had a regular magic lantern, or that he had fitted 
 up his concave mirror in a box containing the figures of 
 his devils, and that this box with its lights was carried 
 home with the party, we can easily account for the decla- 
 ration of the boy, " that, as they were going home to their 
 houses in the quarter of Banchi, two of the demons whom 
 we had seen at the amphitheatre, went on before us leaping 
 and skipping, sometimes running upon the roofs of the houses, 
 and sometimes upon the ground." 
 
 The introduction of the magic lantern as an optical in- 
 strument, supplied the magicians of the seventeenth century 
 with one of their most valuable tools. The use of the 
 concave mirror, which does not appear to have been even 
 put up into the form of an instrument, required a separate 
 apartment, or at least that degree of concealment which 
 it was difficult on ordinary occasions to command ; but 
 the magic lantern, containing in a small compass its 
 lamp, its lenses, and its sliding figures, was peculiarly 
 fitted for the itinerant conjurer, who had neither the 
 means of providing a less portable and more expensive 
 apparatus, nor the power of transporting and erecting it. 
 
 The magic lantern shown in the annexed figure consists 
 of a dark lantern A B, containing a lamp G, and a con- 
 cave metallic mirror M N ; and it is so constructed that 
 when the lamp is lighted, not a ray of light is able to 
 escape from it. Into the side of the lantern is fitted a 
 double tube C D, the outer half of which D, is capable 
 of moving within the other half. A large plano-convex 
 
MAGIC LANTERN. 
 
 155 
 
 lens C, is fixed at the inner end of the double tube, and 
 a small convex lens D, at the outer end ; and to the fixed 
 tube C E, there is joined a groove E F, in which the 
 sliders containing the painted objects are placed, and 
 through which they can be moved. Each slider contains 
 a series of figures or pictures painted on glass with highly- 
 
 Fig. 5. 
 
 transparent colours. The direct light of the lamp G, and 
 the light reflected from the mirror M N, falling upon the 
 illuminating lens C, is concentrated by it so as to throw 
 a brilliant light upon the painting on the slider, and as 
 this painting is in the conjugate focus of the convex lens 
 D, a magnified image of it will be formed on a white wall 
 or white cloth placed at P Q. If the lens D is brought 
 nearer to E F, or to the picture, the distinct image will 
 be more magnified, and will be formed at a greater dis- 
 tance from D, so that if there is any particular distance 
 of the image which is more convenient than another, or any 
 particular size of the object which we wish, it can be 
 obtained by varying the distance of the lens D from E F. 
 When the image is received on an opaque ground, as is 
 commonly the case, the spectators are placed in the same 
 room with the lantern ; but for the purposes of deception, 
 
156 LETTEES ON NATURAL MAGIC. 
 
 it would be necessary to place the lantern in another 
 apartment like the mirror in Fig. 4, and to throw the 
 magnified pictures on a large plate of ground glass, or a 
 transparent gauze screen, stretched across an opening 
 E F, Fig. 4, made in the partition which separates the 
 spectators from the exhibitor. The images might, like 
 those of the concave mirror, be received upon wreaths of 
 smoke. These images are of course always inverted in 
 reference to the position of the painted objects ; but in 
 order to render them really erect, we have only to invert 
 the sliders. The representations of the magic lantern 
 never fail to excite a high degree of interest, even when 
 exhibited with the ordinary apparatus ; but by using 
 double sliders, and varyin^their movements, very striking 
 effects may be produced. A smith, for example, is made 
 to hammer upon his anvil, a figure is thrown into the 
 attitude of terror by the introduction of a spectral appa- 
 rition, and a tempest at sea is imitated, by having the 
 sea on one slider, and the ships on other sliders, to which 
 an undulatory motion is communicated. 
 
 The magic lantern is susceptible of great improvement 
 in the painting of the figures, and in the mechanism and 
 combination of the sliders. A painted figure which ap- 
 pears well executed to the unassisted eye, becomes a mere 
 daub when magnified 50 or 100 times ; and when we 
 consider what kind of artists are employed in their execu- 
 tion, we need not wonder that this optical instrument has 
 degenerated into a mere toy for the amusement of the 
 young. Unless for public exhibition, the expense of 
 exceedingly minute and spirited drawings could not be 
 afforded ; but I have no doubt that if such drawings were 
 executed, a great part of the expense might be saved by 
 engraving them on wood, and transferring their outline 
 to the glass sliders. 
 
 A series of curious representations m ight be effected, 
 
MAGIC LANTERN. 157 
 
 by inserting glass plates containing suitable figures in a 
 trough having two of its sides parallel, and made of plate 
 glass. The trough must be introduced at E F, so that 
 the figure on the glass is at the proper distance from the 
 object lens D. When the trough is filled with water or 
 with any transparent fluid, the picture at P Q will be 
 seen with the same distinctness as if the figure had been 
 introduced by itself into the groove E F ; but if any 
 transparent fluid of a different density from water is 
 mixed with it, so as to combine with it quickly or slowly, 
 the appearance of the figure displayed at P Q will under- 
 go singular changes. If spirits of wine, or any ardent 
 spirit, are mixed with the water, so as to produce through- 
 out its mass partial variations of density, th figure at 
 P Q will be as it were broken down into a thousand 
 parts, and will recover its continuity and distinctness 
 when the two fluids have combined. If a fluid of less 
 density than water is laid gently upon the water, so as to 
 mix with it gradually, and produce a regular diminution 
 of density downwards ; or if saline substances soluble in 
 water are laid at the bottom of the trough, the density 
 will diminish upwards, and the figure will undergo the 
 most curious elongations and contractions. Analogous 
 effects may be produced by the application of heat to the 
 surface or sides of the trough, so that we may effect at 
 the same time both an increase and a diminution in the 
 density of the water, in consequence of which the magni- 
 fied images will undergo the most remarkable transforma- 
 tions. It is not necessary to place the glass plate which 
 contains the figure within the trough. It may be placed 
 in front of it, and by thus creating as it were an atmo- 
 sphere with local variations of density we may exhibit the 
 phenomena of the mirage and of looming, in which the in- 
 verted images of ships and other objects are seen in the 
 air, as described in another letter. 
 
158 LETTERS ON NATURAL MAGIC. 
 
 The power of the magic lantern has been greatly ex- 
 tended by placing it on one side of the transparent screen 
 of taffetas which receives the images while the spectators 
 are placed on the other side, and by making every part of 
 the glass sliders opaque, excepting the part which forms 
 the figures. Hence all the figures appear luminous on a 
 black ground, and produce a much greater effect with the 
 same degree of illumination. An exhibition depending 
 on these principles was brought out by M. Pliilipstal in 
 1802 under the name of the Phantasmagoria, and when it 
 was shown in London and Edinburgh it produced the 
 most impressive effects upon the spectators. The small 
 theatre of exhibition was lighted only by one hanging 
 lamp, the dame of which was drawn up into an opaque 
 chimney or shade when the performance began. In this 
 " darkness visible " the curtain rose, and displayed a cave 
 with skeletons and other terrific figures in relief upon its 
 walls. The flickering light was then drawn up beneath 
 its shroud, and the spectators, in total darkness, found 
 themselves in the middle of thunder and lightning. A 
 thin transparent screen had, unknown to the spectators, 
 been let down after the disappearance of the light, and 
 upon it the flashes of lightning and all the subsequent 
 appearances were represented. This screen being half- 
 way between the spectators and the cave which was first 
 shown, and being itself invisible, prevented the observers 
 from having any idea of the real distance of the figures, 
 and gave them the entire character of aerial pictures. 
 The thunder and lightning were followed by the figures 
 of ghosts, skeletons, and known individuals, whose eyes 
 and mouth were made to move by the shifting of combined 
 sliders. After the first figure had been exhibited for a 
 short time, it began to grow less and less, as if removed 
 to a great distance, and at last vanished in a small cloud 
 of light. Out of this same cloud the germ of another 
 
MAGIC LANTERN. 159 
 
 figure began to appear, and gradually grew larger and 
 larger, and approached the spectators till it attained its 
 perfect development. In this manner, the head of Dr. 
 Franklin was transformed into a skull; figures which 
 retired with the freshness of life came back in the form 
 of skeletons, and the retiring skeletons returned in the 
 drapery of flesh and blood. 
 
 The exhibition of these transmutations was followed by 
 spectres, skeletons, and terrific figures, which, instead of 
 receding and vanishing as before, suddenly advanced 
 upon the spectators, becoming larger as they approached 
 them, and finally vanished by appearing to sink into the 
 ground. The effect of this part of the exhibition was 
 naturally the most impressive. The spectators were not 
 only surprised but agitated, and many of them were of 
 opinion that they could have touched the figures. M. 
 Robertson, at Paris, introduced along with his pictures the 
 direct shadows of living objects, which imitated coarsely 
 the appearance of those objects in a dark night or in 
 moonlight. 
 
 All these phenomena were produced by varying the 
 distance of the magic lantern A B, Fig. 5, from the screen 
 P Q, which remained fixed, and at the same time keeping 
 the image upon the screen distinct, by increasing the 
 distance of the lens D from the sliders in E F. When 
 the lantern approached to P Q, the circle of light P Q, or 
 the section of the cone of rays P D Q, gradually dimi- 
 nished, and resembled a small bright cloud, when D was 
 close to the screen. At this time a new figure was put 
 in, so that when the lantern receded from the screen, the 
 old figure seemed to have been transformed into the new 
 one. Although the figure was always at the same distance 
 from the spectators, yet, owing to its gradual diminution 
 in size, it necessarily appeared to be retiring to a distance. 
 When the magic lantern was withdrawn from P Q, and 
 
160 
 
 LETTERS ON NATURAL MAGIC. 
 
 the lens D at the same time brought nearer to E F, the 
 image in P Q gradually increased in size, and therefore 
 seemed in the same proportion to be approaching the 
 spectators. 
 
 Superior as this exhibition was to any representation 
 that had been previously made by the magic lantern, it 
 still laboured under several imperfections. The figures 
 were poorly drawn, and in other respects not well executed, 
 and no attempt whatever was made to remove the optical 
 incongruity of the figures becoming more luminous when 
 they retired from the observer, and more obscure when 
 they approached to him. The variation of the distance of 
 the lens D from the sliders in E F was not exactly 
 adapted to the motion of the lantern to and from the 
 screen, so that the outline of the figures was not equally 
 distinct during their variations of magnitude. 
 
 Dr. Thomas Young suggested the arrangement shown 
 in Fig. 6 for exhibiting the phantasmagoria. The magic 
 
 Fig. 6. 
 
 lantern is ' mounted on a small car H, which runs on 
 wheels W W. The direct light of the lamp G, and that 
 reflected from the mirror M, is condensed by the illumina- 
 ting lenses C, upon the transparent figures in the opaque 
 sliders at E, and the image of these figures is formed at 
 
PHANTASMAGORIC EXHIBITIONS. 161 
 
 P Q, by the object lens D. When the car H is drawn 
 back on its wheels, the rod I K brings down the point K, 
 and, by means of the rod K L, pushes the lens D nearer 
 to the sliders in E F, and when the car advances to P Q, 
 the point K is raised, and the rod K L draws out the lens 
 D from the slider, so that the image is always in the 
 conjugate focus of D, and therefore distinctly painted on 
 the screen. The rod K N must be equal in length to I K , 
 and the point I must be twice the focal length of the lens 
 D before the object, L being immediately under the focus 
 of the lens. In order to diminish the brightness of the 
 image when it grows small and appears remote, Dr. Young 
 contrived that the support of the lens D should suffer a 
 screen S to fall and intercept a part of the light. This 
 method, however, has many disadvantages ; and we are 
 satisfied that the only way of producing a variation in the 
 light corresponding to the variation in the size of the 
 image, is to use a single illuminating lens C, and to cause 
 it to approach E F, and throw less light upon the figures 
 when D is removed from E F, and to make C recede 
 from E F when D approaches to it. The lens C should 
 therefore be placed in a mean position corresponding to a 
 mean .distance of the screen and to the ordinary size of 
 the figures, and should have the power of being removed 
 from the slider E F, when a greater intensity of light is 
 required for the images when they are rendered gigantic, 
 and of being brought close to E F when the images are 
 made small. The size of the lens C ought of course to be 
 such that the section of its cone of rays at E F is equal to 
 the size of the figure on the slider when C is at its greatest 
 distance from the slider. 
 
 The method recommended by Dr. Young for pulling 
 out and pushing in the object lens D, according as the 
 lantern approaches to or recedes from the screen, is very 
 ingenious and effective. It is, however, clumsy in itself, 
 
162 LETTERS ON NATURAL MAGIC. 
 
 and the connexion of the levers with the screen, and their 
 interposition between it and the lantern, must interfere 
 with the operations of the exhibitor. It is, besides, suited 
 only to short distances between the screen and the lantern ; 
 for when that distance is considerable, as it must sometimes 
 require to be, the levers K L, K I, K T would bend by 
 the least strain, and become unfitted for their purpose. 
 For these reasons, the mechanism which adjusts the lens 
 D should be moved by the axle of the front wheels, the 
 tube which contains the lens should be kept at its greatest 
 distance from E F by a slender spring, and should be 
 pressed to its proper distance by the action of a spiral 
 cam suited to the optical relation between the two con- 
 jugate focal distances of the lens. 
 
 Superior as the representations of the phantasmagoria 
 are to those of the magic lantern, they are still liable to 
 the defect which we have mentioned, namely, the necessary 
 imperfection of the minute transparent figures when mag- 
 nified. This defect cannot be remedied by employing 
 the most skilful artists. Even Michael Angelo would 
 have failed in executing a figure an inch long with trans- 
 parent varnishes, when all its imperfections were to be 
 magnified. In order, therefore, to perfect the art of repre- 
 senting phantasms, the objects must be living ones, and in 
 place of chalky ill-drawn figures mimicking humanity by 
 the most absurd gesticulations, we shall have phantasms 
 of the most perfect delineation, clothed in real drapery, 
 and displaying all the movements of life. The apparatus 
 by which such objects may be used may be called the 
 catadioptrical phantasmagoria, as it operates both by re- 
 flection and refraction. 
 
 The combination of mirrors and lenses which seems 
 best adapted for this purpose is shown in Fig. 7, where 
 A B is a living figure placed before a large concave 
 mirror M N, by means of which a diminished and inverted 
 
CATADIOPTRICAL PHANTASMAGORIA. 
 
 163 
 
 image of it is formed at a b. If P Q is the transparent 
 screen upon which the image is to be shown to the spec- 
 tators on the right hand of it, a large lens L L must be so 
 placed before the image a b as to form a distinct and erect 
 picture of it at A' B' upon the screen. When the image 
 A' B' is required to be the exact size of A B, the lens L L 
 must magnify the small image a b as much as the mirror 
 M N diminishes the figure A B. The living object A B, 
 the mirror M N, and the lens L L, must all be placed in 
 a moveable car for the purpose of producing the variations 
 in the size of the phantasms, and the transformations of 
 one figure into another. The contrivance for adjusting 
 the lens L L to give a distinct picture at different 
 
 Fig. 7. 
 
 M 
 
 distances of the screen will of course be required in the 
 present apparatus. In order to give full effect to the 
 phantasms, the living objects at A B will require to be 
 illuminated in the strongest manner, and should always 
 be dressed either in white or in very luminous colours, 
 and in order to give them relief a black cloth should be 
 stretched at some distance behind them. Many interesting 
 effects might also be produced by introducing at A B fine 
 paintings and busts. 
 
164 
 
 LETTERS ON NATURAL MAGIC. 
 
 It would lead us into too wide a field were we to detail 
 the immense variety of resources which the science of optics 
 furnishes for such exhibitions. One of these, however, is 
 too useful to be passed without notice. If we interpose a 
 prism with a small refracting angle between the image a b, 
 Fig. 7, and the lens L L, the part of the figure immediately 
 opposite to the prism will be as it were detached from the 
 figure, and will be exhibited separately on the screen P Q. 
 Let us suppose that this part is the head of the figure. 
 It may be detached vertically, or lifted from the body as 
 if it were cut off, or it may be detached downwards and 
 placed on the breast as if the figure were deformed. In 
 detaching the head vertically or laterally, an opaque screen 
 must be applied to prevent any part of the head from 
 being seen by rays which do not pass through the prism ; 
 but this and other practical details will soon occur to those 
 who put the method to an experimental trial. The applica- 
 tion of the prism is shown in Fig. 8, where a b is the 
 
 Fig. S. 
 
 inverted image formed by a concave mirror, A B C a 
 prism with a small refracting angle B C A, placed between 
 a b and the lens L L, s a small opaque screen, and A B 
 the figure with its head detached. A hand may be made 
 to grasp the hair of the head, and the aspect of death may 
 be given to it, as if it had been newly cut off. Such a 
 representation could be easily made, and the effect upon 
 
CATADIOPTRICAL PHANTASMAGORIA. 165 
 
 the spectators would be quite overpowering. The lifeless 
 head might then be made to recover its vitality, and be 
 safely replaced upon the figure. If the head A of the 
 living object A B, Fig. 7, is covered with black cloth, the 
 head of a person or of an animal placed above A might be 
 set upon the shoulders of the figure A B by the refraction 
 of a prism. 
 
 When the figure a 6, Fig. 8, is of very small dimensions, 
 as in the magic lantern, a small prism of glass would 
 answer the purpose required of it ; but in public exhibi- 
 tions, where the image a b must be of a considerable size, 
 if formed by a concave mirror, a very large prism would 
 be necessary. This, however, though impracticable with 
 solid glass, may be easily obtained by means of two large 
 pieces of plate glass made into a prismatic vessel and filled 
 with water. Two of the glasses of a carriage window 
 would make a prism capable of doubling the whole of the 
 bust of a living person placed as an object at A B, Fig. 7, 
 so that two perfectly similar phantasms might be exhibited. 
 In those cases where the images before the lens L L are 
 small, they may be doubled and even tripled by interposing 
 a well-prepared plate of calcareous spar, that is, crossed 
 by a thin film. These images would possess the singular 
 character of being oppositely coloured, and of changing 
 their distances and their colours by slight variations in 
 the positions of the plate.* 
 
 In order to render the images which are formed by the 
 glass and water prisms as perfect as possible, it would 
 be easy to make them achromatic, and the figures might 
 be multiplied to any extent by using several prisms, 
 having their refracting edges parallel, for the purpose of 
 giving a similarity of position to all the images. 
 
 Among the instruments of natural magic which were 
 in use at the revival of science, there was one invented by 
 * See Edin. Encyclopaedia, Art. OPTICS, vol. xv. p. 61 1. 
 
166 LETTERS ON NATURAL MAGIC. 
 
 Kircher for exhibiting the mysterious handwriting on the 
 wall of an apartment from which the magician and his 
 apparatus were excluded. The annexed figure represents 
 this apparatus, as given by Schottus. The apartment in 
 which the spectators are placed is between L L and G H, 
 and there is an open window in the side next L L, 
 G H being the inside of the wall opposite to the window. 
 Upon the face of the plane speculum E F are written the 
 words to be introduced, and when a lens L L is placed at 
 such a distance from the speculum, and of such a focal 
 length that the letters and the place of their representa- 
 tion are in its conjugate foci, a distinct image of the 
 
 Fig. 9. 
 
 writing will be exhibited on the wall at G H. The letters 
 on the speculum are of course inverted, as seen at E F, 
 and when they are illuminated by the sun's rays S, 
 as shown in the figure, a distinct image, as Schottus 
 assures us, may be formed at the distance of 500 feet. In 
 this experiment the speculum is by no means necessary. 
 If the letters are cut out of an opaque card, and illumi- 
 nated by the light of the sky in the day, or by a lamp 
 during night, their delineation on the wall would be 
 equally distinct. In the daytime it would be necessary 
 to place the letters at one end of a tube or oblong box, 
 and the lens at the other end. As this deception is per- 
 formed when the spectators are unprepared for any such 
 
KIBCHER'S MYSTERIOUS HANDWRITING. 167 
 
 exhibition, the warning written in luminous letters on the 
 wall, or any word associated with the fate of the individual 
 observer, could not fail to produce a singular effect upon 
 his mind. The words might be magnified, diminished, 
 multiplied, coloured, and obliterated, in a cloud of light, 
 from which they might again reappear by the methods 
 already described, as applicable to the magic lantern. 
 
 The art of forming aerial representations was a great 
 desideratum among the opticians of the seventeenth 
 century. Vitellio and others had made many unsuccess- 
 ful attempts to produce such images, and the speculations 
 of Lord Bacon on the subject are too curious to be with- 
 held from the reader. 
 
 " It would be well bolted out," says he, " whether great 
 refractions may not be made upon reflections, as well as 
 upon direct beams. For example, take an empty basin, 
 put an angel or what you will into it ; then go so far from 
 the basin till you cannot see the angel, because it is not 
 in a right line ; then fill the basin with water, and yon 
 shall see it out of its place, because of the refraction. 
 To proceed, therefore, put a looking-glass into a basin of 
 water. I suppose you shall not see the image in a right 
 line or at equal angles, but wide. I know not whether 
 this experiment may not be extended, so as you might see 
 the image and not the glass, which, for beauty and strange- 
 ness, were a fine proof, for then you should see the image 
 like a spirit in the air. As, for example, if there be a 
 cistern or pool of water, you shall place over against it 
 the picture of the devil, or what you will, so as that you 
 do not see the water. Then put a looking-glass in the 
 water ; now if you can see the devil's picture aside, not 
 seeing the water, it would look like the devil indeed. They 
 have an old tale in Oxford, that Friar Bacon walked 
 between two steeples, which was thought to be done by 
 glasses, when he walked upon the ground." 
 
168 
 
 LETTERS ON NATURAL MAGIC. 
 
 Kircher also devoted himself to the production of such 
 images, and he has given in the annexed figure his method 
 of producing them. At the bottom of a polished cylin- 
 drical vessel A B he placed a figure C D, which we pre- 
 sume must have been highly illuminated from below, and 
 to the spectators who looked into the vessel in an oblique 
 direction there was exhibited an image placed vertically in 
 the air as if it were ascending at the mouth of tLe vessel. 
 Kircher assures us that he once exhibited in this manner 
 a representation of the Ascension of our Saviour, and that 
 
 Fir. 10. 
 
 the images were so perfect that the spectators could not 
 be persuaded, till they had attempted to handle them, that 
 they were not real substances. Although Kircher does 
 not mention it, yet it is manifest that the original figure 
 A B must have been a deformed or anamorphous drawing, 
 in order to give a reflected image of just proportions. We 
 doubt, indeed, if the representation or the figure was ever 
 exhibited. It is entirely incompatible with the laws of 
 reflection. 
 
 Among the ingenious arid beautiful deceptions of the 
 seventeenth century, we must enumerate that of the refor- 
 
CYLINDRICAL MIRRORS. 
 
 169 
 
 mation of distorted pictures by reflection from cylindrical 
 and conical mirrors. In these representations the orig inal 
 image from which a perfect picture is produced is o ften 
 so completely distorted, that the eye cannot trace i n it 
 the resemblance to any regular figure, and the greatest 
 degree of wonder is of course excited, whether the original 
 
 Fig. 11. 
 
 image is concealed or exposed to view. These distorted 
 pictures may be drawn by strict geometrical rules ; but I 
 have shown in Fig. 11 a simple and practical method 
 of executing them. Let M N be an accurate cylincler 
 made of tin-plate or of thick pasteboard. Out of the farther 
 side of it cut a small aperture abed; and out of the 
 nearer side cut a larger one A B C D, the size of the 
 picture to be distorted. Having perforated the outline of 
 
170 LETTERS ON NATURAL MAGIC. 
 
 the picture with small holes, place it on the opening 
 A B C D so that its surface may be cylindrical. Let a 
 candle or a bright luminous object, the smaller the better, 
 be placed at S, as far behind the picture A B C D as the 
 eye is afterwards to be placed before it, and the light 
 passing through the small holes will represent on a hori- 
 zontal plane a distorted image of the picture A' B' C' D', 
 which when sketched in outline with a pencil, and shaded 
 or coloured, will be ready for use. If we now substitute 
 a polished cylindrical mirror of the same size in place of 
 
 Fig. 12. 
 
 M N, then the distorted picture when laid horizontally at 
 A. ! B' C' D' will be restored to its original state when seen 
 by reflection at A B C D in the polished mirror. It 
 would be an improvement on this method to place at 
 A B C D a thin and flexible plate of transparent mica, 
 having drawn upon it with a sharp point or painted upon 
 it the figure required. The projected image of this 
 figure at A' B' C' D' may then be accurately copied. 
 
 "flie effect of a cylindrical mirror is shown in Fig. 12, 
 which is copied from an old one which we have seen in 
 use. 
 
 The method above described is equally applicable to 
 concave cylindrical mirrors, and to those of a conical form, 
 
MIEEOES OF VAEIABLE CUEVATUEE. 
 
 171 
 
 and it may also be applied to mirrors of variable curvature, 
 which produce different kinds of distortions from different 
 parts of their surfaces. 
 
 By employing a mirror whose surface has a variable 
 curvature like ABC, Fig. 13, we obtain an instrument 
 for producing an endless variety of caricatures, all of 
 which are characterized by their resemblance to the 
 original, If a figure M N is placed before such a mirror 
 
 Fig. 13. 
 A 
 
 it will of course appear distorted and caricatured ; but even 
 if the figure takes different distances and positions, the 
 variations which the image undergoes are neither suffi- 
 ciently numerous or remarkable to afford much amusement. 
 But if the figure M N is very near the mirror, so that new 
 distortions are produced by the different distances of its 
 different parts from the mirror, the most singular carica- 
 tures may be exhibited. If the figure, for example, bends 
 forward his head and the upper part of his body, they 
 will swell in size, leaving his lower extremities short and 
 slender. If it draws back the upper part of the body, and 
 advances the limbs, the opposite effect will take place. 
 In like manner different sides of the head, the right or 
 the left side of it, the brow or the chin, may be swelled 
 
172 LETTERS ON NATURAL MAGIC. 
 
 and contracted at pleasure. By stretching out the arms 
 before the body they become like those of an orang-outang, 
 and by drawing them back they dwindle into half their 
 regular size. All these effects, which depend greatly on 
 the agility and skill of the performer, may be very much 
 increased by suitable distortions in his own features and 
 figure. The family likeness, which is of course never 
 lost in all the variety of figures which are thus produced, 
 adds greatly to the interest of the exhibition ; and we 
 have seen individuals so annoyed at recognizing their own 
 likeness in the hideous forms of humanity which were 
 thus delineated, that they could not be brought to con- 
 template them a second time. If the figure is inanimate, 
 like the small cast of a statue, the effect is very curious, 
 as the swelling and contracting of the parts and the sudden 
 change of expression give a sort of appearance of vitality 
 to the image. The inflexibility of such a figure, however, 
 is unfavourable to its transformation into caricatures. 
 
 Interesting as these metamorphoses are, they lose in 
 the simplicity of the experiment much of the wonder 
 which they could not fail to excite if exhibited on a great 
 scale, where the performer is invisible, and where it is 
 practicable to give an aerial representation of the cari- 
 catured figures. This may be done by means of the 
 apparatus shown in Fig. 7,* where we may suppose A B 
 to be the reduced image seen in the reflecting surface 
 ABC, Fig. 13.f By bringing this image nearer the 
 mirror M N, Fig. 7, a magnified and inverted image of it 
 may be formed at a 6, of such a magnitude as to give the 
 last image in P Q the same size as life. Owing to the 
 loss of light by the two reflections, a very powerful illu- 
 mination would be requisite for the original figure. If 
 such an exhibition were well got up the effect of it would 
 be very striking. 
 
 * Page 163. f Page 171. 
 
CONVERSION OF CAMEOS INTO INTAGLIOS. 173 
 
 LETTER V. 
 
 Miscellaneous optical illusions Conversions of cameos into intaglios 
 or elevations into depressions, and the reverse. Explanation of 
 this c/ass of deceptions Singular effects of illumination with 
 light of one simple colour Lamps for producing homogeneous 
 yellow light Meth^s of increasing the effect of this exhibition 
 Method of reading the inscription of coins in the dark Art of 
 deciphering the effaced inscription of coins Explanation of these 
 singular effects Apparent motion of the eyes in portraits 
 Remarkable examples of this Apparent motion of the features 
 of a portrait, when the eyes are made to move Remarkable 
 experiment of breathing light and darkness. 
 
 IN the preceding letter I have given an account of the 
 most important instruments of Natural Magic which 
 depend on optical principles ; but there still remain 
 several miscellaneous phenomena on which the stamp of 
 the marvellous is deeply impressed, and the study of 
 which is pregnant with instruction and amusement. 
 
 One of the most curious of these is that false percep- 
 tion in vision by which we conceive depressions to be 
 elevations and elevations depressions, or by which in- 
 taglios are converted into cameos, and cameos into in- 
 taglios. This curious fact seems to have been first 
 observed at one of the early meetings of the Royal Society 
 of London, when one of the members, in looking at a 
 guinea through a compound microscope of new construc- 
 tion, was surprised to see the head upon the coin de- 
 pressed, while other members could only see it embossed 
 as it really was. 
 
 While using telescopes and compound microscopes, 
 Dr. Gmelin of Wurtemburg observed the same fact. The 
 
174 LETTERS ON NATURAL MAGIC. 
 
 protuberant parts of objects appeared to him depressed, 
 and the depressed parts protuberant ; but what perplexed 
 him extremely, this illusion took place at some times and 
 not at others, in some experiments and not in others, and 
 appeared to some eyes and not to others. 
 
 After making a great number of experiments, Dr. Gme- 
 lin is said to have constantly observed the following 
 effects : Whenever he viewed fc any object rising upon a 
 plane of any colour whatever, provided it was neither 
 white nor shining, and provided the eye and the optical 
 tube were directly opposite to it, the elevated parts 
 appeared depressed, and the depressed parts elevated. 
 This happened when he was viewing a seal, and as often 
 as he held the tube of the telescope perpendicularly, and 
 applied it in such a manner that its whole surface almost 
 covered the last glass of the tube. The same effect was 
 produced when a compound microscope was used. When 
 the object hung perpendicularly from a plane, and the 
 tube was supported horizontally and directly opposite to 
 it, the illusion also took place, and the appearance was 
 not altered when the object hung obliquely and even 
 horizontally. Dr. Gmelin is said to have at last dis- 
 covered a method of preventing this illusion, which was, 
 by looking not towards the centre of the convexity, but 
 at first to the edges of it only, and then gradually taking 
 in the whole. " But why these things should so happen, 
 he did not pretend to determine." 
 
 The best method of observing this deception is to view 
 the engraved seal of a watch with the eye-piece of an 
 achromatic telescope, or with a compound microscope, or 
 any combination of lenses which inverts the objects that 
 are viewed through it.* The depression in the seal will 
 
 * A single convex lens will answer the .purpose, provided we hold 
 the eye six or eight inches behind the image of the seal formed in 
 is conjugate focus. 
 
CONVERSION OF CAMEOS INTO INTAGLIOS, 
 
 175 
 
 immediately appear an elevation, like the wax impression 
 which is taken from it ; and though we know it to be 
 hollow, and feel its concavity with the point of our 
 finger, the illusion is so strong that it continues to appear 
 a protuberance. The cause of this will be understood 
 from Fig. 14, where S is the window of the apartment, 
 
 Fig. 14. 
 
 or the light which illuminates the hollow seal L E, whose 
 shaded side is of course on the same side L with the 
 light. If we now invert the seal with one or more lenses, 
 so that it may look in. the opposite direction, it will 
 appear to the eye as in Fig. 15, with the shaded side L 
 
 Fig. 15. 
 
 farthest from the window. But as we know that the 
 window is still on our left hand, and that the light falls 
 in the direction K L, and as every body with its shaded 
 side farthest from the light must necessarily be convex 
 or protuberant, we immediately believe that the hollow 
 seal is now a cameo or bas-relief. The proof which the 
 eye thus receives of the seal being raised, overcomes the 
 evidence of its being hollow derived from our actual 
 knowledge, and from the sense of touch. In this experi- 
 
176 LETTERS ON NATURAL MAGIC. 
 
 ment the deception takes place from our knowing the 
 real direction of the light which falls upon the seal ; for 
 if the place of the window, with respect to the seal, had 
 been inverted as well as the seal itself, the illusion could 
 not have taken place. 
 
 In order to explain this better, let us suppose the seal 
 L K, Fig. 14, to be illuminated with a candle S, the 
 place of which we can change at pleasure. If we invert 
 L K it will rise into a cameo, as in Fig. 15 ; and if we 
 then place another candle D on the other side of it, as in 
 Fig. 16, the hollow seal will be equally illuminated on 
 all sides, and it will sink down into a cavity or intaglio. 
 If the two candles do not illuminate the seal equally, or 
 
 Fig. 16. 
 
 if any accidental circumstance produces a belief that the 
 light is wholly or principally on one side, the mind will 
 entertain a corresponding opinion respecting the state of 
 the seal, regarding it as a hollow if it believes the light 
 to come wholly or principally from the right hand, and as 
 a cameo if it believes the light to come from the left 
 hand. 
 
 If we use a small telescope to invert the seal, and if 
 we cover up all the candle but its flame, and arrange the 
 experiment so that the candle may be inverted along 
 with the image, the seal will still retain its concavity, 
 because the shadow is still on the same side with the 
 illuminating body. 
 
 If we make the same experiments with the raised im- 
 pression of the seal taken upon wax, we shall observe the 
 
CONVERSION OF CAMEOS INTO INTAGLIOS. 177 
 
 very same phenomena, the seal being depressed when it 
 alone is inverted, and retaining its convexity when the 
 light is inverted along with it. 
 
 The illusion, therefore, under our consideration is the 
 result of an operation of our own minds, whereby we 
 judge of the forms of bodies by the knowledge we have 
 acquired of light and shadow. Hence the illusion depends 
 on the accuracy and extent of our knowledge on this 
 subject ; and while some persons are under its influence, 
 others are entirely insensible to it. When the seat or 
 hollow cavity is not polished, but ground, and the surface 
 round it of uniform colour and smoothness, almost every 
 person, whether young or old, learned or ignorant, will 
 be subject to the illusion ; because the youngest and the 
 most careless observers cannot but know that the shadow 
 
 Fig. 17. 
 
 of a hollow is always on the side next the light, and the 
 shadow of a protuberance on the side opposite to the 
 light ; but if the object is the raised impression of a seal 
 upon wax, I have found that when inverted it still seemed 
 raised to the three youngest of six persons, while the 
 three eldest were subject to the deception. 
 
 This illusion may be dissipated by a process of reason- 
 ing arising from the introduction of a new circumstance 
 in the experiment. Thus, let E L, Fig. 18, be the in- 
 verted seal, which consequently appears raised, and let 
 an opaque and unpolished pin A be placed on one side of 
 the seal. Its shadow will be of course opposite the 
 candle as at B. In this case the seal, which had become 
 
178 LETTERS ON NATURAL MAGIC. 
 
 a cameo by its inversion, will now sink down into a 
 cavity by the introduction of the pin and its shadow ; for as 
 the pin and its shadow are inverted, as shown in Fig. 18, 
 while the candle retains its place, the shadow of the pin 
 falling in the direction A B is a stronger proof to the 
 eye that the light is coming from the right hand, than 
 the actual knowledge of the candle being on the left 
 hand, and therefore the cameo necessarily sinks into a 
 cavity, or the shadow is now on the same side as the light. 
 This experiment will explain to us why on some occasions 
 an* acute observer will elude the deception, while every 
 other person is subject to it. Let us suppose that a 
 
 Fig. 18. 
 
 particle of dust, or a little bit of wax, capable of giving 
 a shadow, is adhering to the surface of the seal, an 
 ordinary observer will take no notice of this, or if he 
 does, he will probably not make it a subject of considera- 
 tion, and will therefore see the head on the seal raised 
 into a cameo; but the attentive observer noticing the 
 little protuberance, and observing that its shadow lies 
 to the left of it, will instantly infer that the light comes 
 in that direction, and will still see the seal hollow. 
 
 I have already mentioned that in some cases even the 
 sense of touch does not correct the erroneous perception. 
 We of course feel that the part of the hollow on which 
 the finger is placed is actually hollow ; but if we look at 
 the other part of the hollow it will still appear raised. 
 
 By using two candles yielding different degrees of light, 
 
CONVERSION OF CAMEOS INTO INTAGLIOS. 179 
 
 and thus giving an uncertainty to the direction of the 
 light, we may weaken the illusion in any degree we 
 choose, so as to overpower it by touch or by a process of 
 reasoning. 
 
 I have had occasion to observe a series of analogous 
 phenomena arising from the same cause, but produced 
 without any instrument for inverting the object. If A B, 
 for example, is a plate of mother-of-pearl, and L K a 
 circular or any other cavity (Fig. 19) ground or turned 
 in it, then if this cavity is illuminated by a candle or a 
 
 Fig. 19. 
 
 window at S, in place of there being a shadow of the mar- 
 gin L of the hollow next the light, as there would have 
 been had the body been opaque, a quantity of bright re- 
 fracted light will appear where there would have been a 
 shadow, and the rest of the cavity will be comparatively 
 obscure, as if it were in shade. The necessary consequence 
 of this is, that the cavity will appear as an elevation when 
 seen only by the naked eye, as it is only an elevated sur- 
 face that could have its most luminous side at L. 
 
 Similar illusions take place in certain pieces of polished 
 wood, calcedony, and mother-of-pearl, where the surface 
 is perfectly smooth. This arises from there being at that 
 place a knot or growth, or nodule of different transparency 
 from the surrounding mass, and the cause of it will be 
 understood from Fig. 20. Let m o be the surface of a 
 mahogany table, A m o B a section of the table, and m n o 
 a section of a knot more transparent than the rest of the 
 
180 LETTERS ON NATURAL MAGIC. 
 
 mass. Owing to the transparency of the thin edge at o, 
 opposite to the candle S, the side o is illuminated, while 
 the rest of the knot is comparatively dark, so that on the 
 principles already explained the spot m n o appears to be 
 a hollow in the table. From this cause arises the appear- 
 ance of dimples in certain plates of calcedony called 
 hammered calcedony, owing to its having the look of 
 being dimpled with a hammer. The surface on which 
 these cavities are seen is a section of small spherical 
 aggregations of siliceous matter, which exhibit the same 
 
 Fig. 20. 
 
 phenomena as the cavities in wood. Mother-of-pearl 
 presents the very same phenomena, and it is indeed so 
 common in this substance that it is nearly impossible to 
 find a mother-of-pearl button or counter which seems to 
 have its surface flat, although they are perfectly so when 
 examined by the touch. Owing to the different refraction 
 of the incident light by the different growths of the shell 
 cut in different directions by the artificial surface, like the 
 annual growth of wood in a dressed plank, the surface has 
 necessarily an unequal and undulating appearance. 
 
 Among the wonders of science there are perhaps none 
 more surprising than the effects produced upon coloured 
 objects by illuminating them with homogeneous light, or 
 light of one colour. The light which emanates from the 
 sun, and by which all the objects of the material world 
 are exhibited to us, is composed of three different colours, 
 red, yellow, and blue, by the mixture of which in different 
 
HOMOGENEOUS YELLOW LIGHT. 181 
 
 proportions all the various hues of nature may be pro- 
 duced. These three colours, when mixed in the propor- 
 tion in which they occur in the sun's rays, compose a 
 purely white light ; but if any body on which this white 
 light falls shall absorb, or stop, or detain within its sub- 
 stance any part of any one or more of these simple colours, 
 it will appear to the eye of that colour which arises from 
 the mixture of all the rays which it does not absorb, or of 
 that colour which white light would have if deprived of 
 the colours which are absorbed. Scarlet cloth, for example, 
 absorbs most of the blue rays and many of the yellow, and 
 hence appears red. Yellow cloth absorbs most of the blue 
 and many of the red rays, and therefore appears yellow, 
 and blue cloth absorbs most of the yellow and red rays. 
 If we were to illuminate the scarlet cloth with pure and 
 unmixed yellow light, it would appear yellow, because the 
 scarlet cloth does not absorb all the yellow rays, but 
 reflects some of them ; and if we illuminate blue cloth 
 with yellow light, it will appear nearly black, because it 
 absorbs all the yellow light, and reflects almost none of it. 
 But whatever be the nature and colour of the bodies on 
 which the yellow light falls, the light which it reflects 
 must be yellow, for no other light falls upon them, and 
 those which are not capable of reflecting yellow light must 
 appear absolutely black, however brilliant be their colour 
 in the light of day. 
 
 As the methods now discovered of producing yellow 
 light in abundance were not known to the ancient con- 
 jurers, nor even to those of later times, they have never 
 availed themselves of this valuable resource. It has been 
 long known that salt thrown into the wick of a flame pro- 
 duces yellow light, but this light is mixed with blue arid 
 green rays, and is, besides, so small in quantity that it 
 illuminates objects only that are in the immediate vicinity 
 of the flame. A method which I have found capable of 
 
182 LETTERS ON NATURAL MAGIC. 
 
 producing it in abundance is shown in Fig. 21, where A B 
 is a lamp containing at A a large quantity of alcohol and 
 water or ardent spirits, which gradually descends into a 
 platina or metallic cup D. This cup is strongly heated 
 by a spirit-lamp L, inclosed in a dark lantern ; and when 
 the diluted alcohol in D is inflamed, it will burn with a 
 fierce and powerful yellow flame : if the flame should 
 not be perfectly yellow, owing to an excess of alcohol, a 
 
 Fi~ 21. 
 
 proportion of salt thrown into the cup will answer the 
 same purpose as a further dilution of the alcohol.* 
 
 A monochromatic lamp for producing yellow light may 
 be constructed most effectually by employing a portable 
 gas lamp containing compressed oil gas. If we allow the 
 gas to escape in a copious stream, and set it on fire, it will 
 form an explosive mixture with the atmospheric air, and 
 will no longer burn with a white flame, but will emit a 
 bluish and reddish light. The force of the issuing gas, 
 * See Edinburgh Transactions, vol. ix. p. 435. 
 
HOMOGENEOUS YELLOW LIGHT. 
 
 183 
 
 or any accidental current of air, is capable of blowing out 
 this flame, so that it is necessary to have a contrivance 
 for sustaining it. The method which I used for this pur- 
 pose is shown in Fig. 22. A small gas tube a b c, arising 
 from the main burner M N of the gas lamp P Q, termi- 
 nates above the burner, and has a short tube d e, moveable 
 up and down within it, so as to be gas-tight. This tube 
 d e, closed at e, communicates with the hollow ring / g, in 
 the inside of which four apertures are perforated in such 
 
 Fig. 22. 
 
 a manner as to throw their jets of gas to the apex of a 
 cone, of which / g is the base. When we cause the gas to 
 flow from the burner M, by opening the main cock A, it 
 will rush into the tube abed, and issue in small flames 
 at the four holes in the ring/</. The size of these flames 
 is regulated by the cock 6. The inflammation, therefore, 
 of the ignited gas will be sustained by these four subsidiary 
 flames through which it passes, independent of any agita- 
 tion of the air, or of the force with which it issues from 
 the burner. On a projecting arm e h, carrying a ring A, 
 
184 LETTERS ON NATURAL MAGIC. 
 
 I fixed a broad collar, made of coarse cotton wick, which 
 had been previously soaked in a saturated solution of 
 common salt. When the gas is allowed to escape at M, 
 with such force as to produce a long and broad column of 
 an explosive mixture of gas and atmospheric air, the bluish 
 flame occasioned by the explosion passes through the 
 salted collar, and is converted by it into a mass of homo- 
 geneous yellow light. This collar will last a long time 
 without any fresh supply of salt, so that the gas lamp will 
 yield a permanent monochromatic yellow flame, which 
 will last as long as there is gas in the reservoir. In place 
 of a collar of cotton wick, a hollow cylinder of sponge, 
 with numerous projecting tufts, may be used, or a collar 
 may be similarly constructed with asbestos cloth, and, if 
 thought necessary, it might be supplied with a saline 
 solution from a capillary fountain. 
 
 Having thus obtained the means of illuminating any 
 apartment with yellow light, let the exhibition be made 
 in a room with furniture of various bright colours, with 
 oil or water coloured paintings on the wall. The party 
 which is to witness the experiment should be dressed in a 
 diversity of the gayest colours ; and the brightest coloured 
 flowers and highly-coloured drawings should be placed on 
 the tables. The room being at first lighted with ordinary 
 lights, the bright and gay colours of everything that it 
 contains will be finely displayed. If the white lights are 
 now suddenly extinguished, and the yellow lamps lighted, 
 the most appalling metamorphosis will be exhibited. The 
 astonished individuals will no longer be able to recognise 
 each other. All the furniture in the room and all the 
 objects which it contains will exhibit only one colour. 
 The flowers will lose their hues. The paintings and 
 drawings will appear as if they were executed in China 
 ink, and the gayest dresses, the brightest scarlets, the 
 purest lilacs, the richest blues, and the most vivid greens 
 
HOMOGENEOUS YELLOW LIGHT. 185 
 
 will all be converted into one monotonous yellow. The 
 complexions of the parties too will suffer a corresponding 
 change. One pallid death-like yellow, 
 
 -like the unnatural hue 
 
 Which autumn plants upon the perished leaf, 
 
 will envelop the young and the old, and the sallow faces 
 will alone escape from the metamorphosis. Each indi- 
 vidual derives merriment from the cadaverous appearance 
 of his neighbour, without being sensible that he is himself 
 one of the ghostly assemblage. 
 
 If, in the midst of the astonishment which is thus 
 created, the white lights are restored at one end of the 
 room, while the yellow lights are taken to the other end, 
 one side of the dress of every person, namely, that next 
 the white light, will be restored to its original colours, 
 while the other side will retain its yellow hue. One 
 cheek will appear in a state of health and colour, while 
 the other retains the paleness of death, and, as the indi- 
 viduals change their position, they will exhibit the most 
 extraordinary transformations of colour. 
 
 If, when all the lights are yellow, beams of white light 
 are transmitted through a number of holes like those in a 
 sieve, each luminous spot will restore the colour of the 
 dress or furniture upon which it falls, and the nankeen 
 family will appear all mottled over with every variety of 
 tint. If a magic lantern is employed to throw upon the 
 walls or upon the dresses of the company luminous figures 
 of flowers or animals, the dresses will be painted with 
 these figures in the real colour of the dress itself. Those 
 alone who appeared in yellow, and with yellow com- 
 plexions, will to a great degree escape all these singular 
 changes. 
 
 If red and blue light could be produced with the same 
 facility and in the same abundance as yellow light, the 
 
 o 
 
186 LETTERS ON NATURAL MAGIC. 
 
 illumination of the apartment with these lights in succes- 
 sion would add to the variety and wonder of the exhibition. 
 The red light might perhaps be procured in sufficient 
 quantity from the nitrate and other salts of strontian ; 
 but it would be difficult to obtain a blue flame of sufficient 
 intensity for the suitable illumination of a large room. 
 Brilliant white lights, however, might be used, having for 
 screens glass troughs containing a mass one or two inches 
 thick of a solution of the ammoniacal carbonate of copper. 
 This solution absorbs all the rays of the spectrum but the 
 blue, and the intensity of the blue light thus produced 
 would increase in the same proportion as the white light 
 employed. 
 
 Among the numerous experiments with which science 
 astonishes ' and sometimes even strikes terror into the 
 ignorant, there is none more calculated to produce this 
 effect than that of displaying to the eye in absolute dark- 
 ness the legend or inscription upon a coin. To do this, 
 take a silver coin (I have always used an old one), and 
 after polishing the surface as much as possible, make the 
 parts of it which are raised rough by the action of an acid, 
 the parts not raised, or those which are to be rendered 
 darkest, retaining their polish. If the coin thus prepared 
 is placed upon a mass of red-hot iron, and removed into a 
 dark room, the inscription upon it will become less 
 luminous than the rest, so that it may be distinctly read 
 by the spectator. The mass of red-hot iron should be 
 concealed from the observer's eye, both for the purpose of 
 rendering the eye fitter for observing the effect, and of 
 removing all doubt that the inscription is really read in 
 the dark, that is, without receiving any light, direct or 
 reflected, from any other body. If, in place of polishing 
 the depressed parts, and roughening its raised parts, we 
 make the raised parts polished, and roughen the depressed 
 parts, the inscription will now be less luminous than the 
 
BEADING COINS IN THE DARK. 187 
 
 depressed parts, and we shall still be able to read it, from 
 its being as it were written in black letters on a white 
 ground. The first time I made this experiment, without 
 being aware of what would be the result, I used a French 
 shilling of Louis XV., and I was not a little surprised to 
 observe upon its surface in black letters the inscription 
 BENEDICTUM SIT NOMEN DEI. 
 
 The most surprising form of this experiment is when 
 we use a coin from which the inscription has been either 
 wholly obliterated, or obliterated in such a degree as to 
 be illegible. When such a coin is laid upon the red-hot 
 iron, the letters and figures become oxidated, and the film 
 of oxide radiating more powerfully than the rest of the 
 coin will be more luminous than the rest of the coin, and 
 the illegible inscription may be now distinctly read, to the 
 great surprise of the observer, who had examined the 
 blank surface of the coin previous to its being placed upon 
 the hot iron. The different appearances of the same coin, 
 according as the raised parts are polished or roughened, 
 are shown in Figs. 23 and 24. 
 
 In order to explain the cause of these remarkable 
 effects, we must notice a method which has been long 
 known, though never explained, of deciphering the in- 
 scriptions on worn-out coins. This is done by merely 
 placing the coin upon a hot iron. An oxidation takes 
 place over the whole surface of the coin, the film of oxide 
 changing its tint with the intensity or continuance of the 
 heat. The parts, however, where the letters of the inscrip- 
 tion had existed oxidate at a different rate from the sur- 
 rounding parts, so that these letters exhibit their shape, 
 and ; become legible, in consequence of the film of oxide 
 which covers them having a different thickness, and there- 
 fore reflecting a different tint from that of the adjacent 
 parts. The tints thus developed sometimes pass through 
 many orders of brilliant colours, particularly pink and 
 
188 
 
 LETTERS ON NATURAL MAGIC. 
 
 green, and settle in a bronze, and sometimes a black tint, 
 resting upon the inscription alone. In some cases the 
 tint left on the trace of the letters is so very faint that it 
 can just be seen, and may be entirely removed by a slight 
 rub of the finger. 
 
 When the experiment is often repeated with the same 
 coin, and the oxidations successively removed after each 
 experiment, the film of oxide continues to diminish, and at 
 last ceases to make its appearance. It recovers the 
 property, however, in the course of time. When the coin 
 is put upon the hot iron, and consequently when the oxi- 
 dation is the greatest, a considerable smoke arises from 
 
 Fig. 24. 
 
 the coin, and this diminishes, like the film of oxide, by 
 frequent repetition. A coin which had ceased to emit 
 this smoke, smoked slightly after having been exposed 
 twelve hours to the air. I have found from numerous 
 trials that it is always the raised parts of the coin, and in 
 modern coins the elevated ledge round the inscription, 
 that becomes first oxidated. In an English shilling of 
 1816 this ledge exhibited a brilliant yellow tint before it 
 appeared on any other part of the coin. 
 
 If we use an uniform and homogeneous disc of silver 
 that has never been hammered or compressed, its surface 
 will oxidate equally, provided all its parts are equally 
 heated. In the process of converting this disc into a coin, 
 
READING- COINS IN THE DARK. 189 
 
 the sunk parts have obviously been most compressed by the 
 prominent parts of the die, and the elevated parts least 
 compressed, the metal being in the latter left as it were in 
 its natural state. The raised letters and figures on a coin 
 have therefore less density than the other parts, and these 
 parts oxidate sooner, or at a lower temperature. When the 
 letters of the legend are worn off by friction, the parts 
 immediately below them have also less density than the 
 surrounding metal, and the site as it were of the letters 
 therefore receives from heat a degree of oxidation, and a 
 colour different from that of the surrounding surface. 
 Hence we obtain an explanation of the revival of the 
 invisible letters by oxidation. 
 
 The same influence of difference of density may be 
 observed in the beautiful oxidations which are produced 
 on the surface of highly-polished steel, heated in contact 
 with air, at temperatures between 430 and 630 of 
 Fahrenheit.* When the steel has hard portions called 
 pins by the workmen, the uniform tint of the film of oxide 
 stops near these hard portions, which always exhibit 
 colours different from those of the rest of the mass. 
 These parts, on account of their increased density, absorb 
 the oxygen of atmospheric air less copiously than the 
 surrounding portions. Hence we see the cause why steel 
 expanded by heat absorbs oxygen, which, when united 
 with the metal, forms the coloured superficial film. As 
 the heat increases, a greater quantity of oxygen is absorbed, 
 and the film increases in thickness. 
 
 These observations enable us to explain the legibility 
 of inscriptions in the dark, whether the coin is in a perfect 
 state, or the letters of it worn off. All black or rough 
 surfaces radiate light more copiously than polished or 
 smooth surfaces, and hence the inscription is luminous when 
 it is rough, and obscure when it is polished, and the letters 
 
 * See Edinburgh Encyclopedia, Art. STEEL, vol. xviii. p. 387. 
 
190 LETTERS ON NATURAL MAGIC. 
 
 covered with black oxide are more luminous than the 
 adjacent parts, on account of the superior radiation of 
 light by the black oxide which covers them. 
 
 By the means now described invisible writing might be 
 conveyed by impressing it upon a metallic surface, and 
 afterwards erasing it by grinding and polishing that 
 surface perfectly smooth. When exposed to a proper 
 degree of heat, the secret would display itself written in 
 oxidated letters. Many amusing experiments might be 
 made upon the same principle. 
 
 A series of curious and sometimes alarming deceptions, 
 arises from the representation of objects in perspective 
 upon a plane surface. One of the most interesting of 
 these depends on the principles which regulate the 
 apparent direction of the eyes in a portrait. Dr. Wollaston 
 has thought this subject of sufficient importance to be 
 treated at some length in the Philosophical Transactions. 
 When we look at any person we direct to them both our 
 face and our eyes, and in this position the circular iris 
 will be in the middle of the white of the eyeball, or, what 
 is the same thing, there will be the same quantity of white 
 on each side of the iris. If the eyes are now moved to 
 either side, while the head remains fixed, we shall readily 
 judge of the change of their direction by the greater or 
 less quantity of white on each side of the iris. This test, 
 however, accurate as it is, enables us only to estimate the 
 extent to which the eyes deviate in direction from the 
 direction of the face to which they belong. But their 
 direction in reference to the person who views them is 
 entirely a different matter ; and Dr. Wollaston is of 
 opinion, that we are not guided by the eyes alone, but are 
 unconsciously aided by the concurrent position of the 
 entire face. 
 
 If a skilful painter draws a pair of eyes with great 
 correctness directed to the spectator, and deviating from 
 
MOTION OF THE EYES IN PORTRAITS. 
 
 191 
 
 tlie general position of the face as much as is usual in 
 good portraits,' it is very difficult to determine their 
 direction, and they will appear to have different directions 
 to different persons. But what is very curious, Dr. 
 Wollaston has shown that the same pair of eyes may be 
 made to direct themselves either to or from the spectator 
 by the addition of other features in which the position of 
 the face is changed. Thus in Fig. 25, the pair of eyes are 
 Fig. 25. 
 
 Fig. 26. 
 
 The nose is obviously the principal feature which pro- 
 duces this change of direction, as it is more subject to 
 change of perspective than any of the other features ; but 
 Dr. Wollaston has shown, by a very accurate experiment, 
 that even a small portion of the nose introduced with the 
 features will carry the eyes along with it. He obtained 
 four exact copies of the same pair of eyes looking at the 
 
190 
 
 LETTERS ON NATURAL MAGIC. 
 
 covered with black oxide are more luminous than the 
 adjacent parts, on account of the superior radiation of 
 light by the black oxide which covers them. 
 
 By the means now described invisible writing might be 
 conveyed by impressing it upon a metallic surface, and 
 afterwards erasing it by grinding and polishing that 
 surface perfectly smooth. When exposed to a proper 
 degree of heat, the secret would display itself written in 
 oxidated letters. Many amusing experiments might be 
 made upon the same principle. 
 
 A series of curious and sometimes alarming deceptions, 
 arises from the representation of objects in perspective 
 
 direction in reference to the person who views them is 
 entirely a different matter ; and Dr. Wollaston is of 
 opinion, that we are not guided by the eyes alone, but are 
 unconsciously aided by the concurrent position of the 
 entire face. 
 
 If a skilful painter draws a pair of eyes with great 
 correctness directed to the spectator, and deviating from 
 
MOTION OF THE EYES IN PORTRAITS. 
 
 191 
 
 the general position of the face as much as is usual in 
 good portraits,' it is very difficult to determine their 
 direction, and they will appear to have different directions 
 to different persons. But what is very curious, Dr. 
 Wollaston has shown that the same pair of eyes may be 
 made to direct themselves either to or from the spectator 
 by the addition of other features in which the position of 
 the face is changed. Thus in Fig. 25, the pair of eyes are 
 Fig. 25. 
 
 looking intently at the spectator, and the face has a cor- 
 responding direction ; but when we cover up the face in 
 Fig. 25 with the face in Fig. 26, which looks to the right, 
 the eyes change their direction, and look to the right also. 
 In like manner, eyes drawn originally to look a little to 
 the right or the left of the spectator may be made to look 
 directly at him by adding suitable features. 
 
 The nose is obviously the principal feature which pro- 
 duces this change of direction, as it is more subject to 
 change of perspective than any of the other features ; but 
 Dr. Wollaston has shown, by a very accurate experiment, 
 that even a small portion of the nose introduced with the 
 features will carry the eyes along with it. He obtained 
 four exact copies of the same pair of eyes looking at the 
 
192 LETTERS ON NATURAL MAGIC. 
 
 spectator, by transferring them upon copper from a steel 
 plate, and having added to each of two pair of them, a 
 nose in one case directed to the right, and in the other, to 
 the left, and to each of the other two pairs a very small 
 portion of the upper part of the nose, all the four pair of 
 eyes lost their front direction, and looked to the right or 
 to the left, according to the direction of the nose, or of the 
 portion of it which was added. 
 
 But the effect thus produced is not limited, as Dr. 
 Wollaston remarks, to the mere change in the direction of 
 the eyes, " for a total difference of character may be given 
 to the same eyes by a due representation of the other 
 features. A lost look of devout abstraction in an uplifted 
 countenance may be exchanged for an appearance of 
 inquisitive archness in the leer of a younger face turned 
 downwards and obliquely towards the opposite side," as in 
 Fig. 27, 28. This, however, is perhaps not an exact 
 expression of the fact. The new character which is said 
 to be given to the eyes is given only to the eyes in com- 
 bination with the new features, or, what is probably more 
 correct, the inquisitive archness is in the other features, 
 and the eye does not belie it. 
 
 Dr. Wollaston has not noticed the converse of these 
 illusions, in which a change of direction is given to fixed 
 features by a change in the direction of the eyes. This 
 effect is finely seen in some magic lantern sliders, where 
 a pair of eyes is made to move in the head of a figure 
 which invariably follows the motion of the eyeballs. 
 
 Having thus determined the influence which the general 
 perspective of the face has upon the apparent direction of 
 the eyes in a portrait, Dr. Wollaston applies it to the ex- 
 planation of the well-known fact, that when the eyes 
 of a portrait look at a spectator in front of it they will 
 follow him, and appear to look at him in every other 
 direction. This curious fact, which has received less con. 
 
MOTION OF THE FEATURES OF A PORTRAIT. 193 
 
 sideratiori than it merits, has been often skilfully em- 
 ployed by the novelist, in alarming the fears or exciting 
 the courage of his hero. On returning to the hall of his 
 ancestors, his attention is powerfully fixed on the grim 
 portraits which surround him. The parts which they 
 have respectively performed in the family history rise 
 to his mind : his own actions, whether good or evil, are 
 called up in contrast, and as the preserver or the destroyer 
 of his line, he stands as it were in judgment before them. 
 
 Fig. 27. 
 
 Fig. 28. 
 
192 LETTERS ON NATURAL MAGIC. 
 
 spectator, by transferring them upon copper from a steel 
 plate, and having added to each of two pair of them, a 
 nose in one case directed to the right, and in the other, to 
 the left, and to each of the other two pairs a very small 
 portion of the upper part of the nose, all the four pair of 
 eyes lost their front direction, and looked to the right or 
 to the left, according to the direction of the nose, or of the 
 portion of it which was added. 
 
 But the effect thus produced is not limited, as Dr. 
 Wollaston remarks, to the mere change in the direction of 
 the eyes, " for a total difference of character may be given 
 to the same eyes by a due representation of the other 
 features. A lost look of devout abstraction in an uplifted 
 countenance may be exchanged for an appearance of 
 inquisitive archness in the leer of a younger face 
 downwards and obliquely towards the 
 Fig. 27, 28. This, 
 expression of t-lr* * 
 to ^ ' 
 
MOTION OF THE FEATURES OF A PORTRAIT. 193 
 
 sideration than it merits, has been often skilfully em- 
 ployed by the novelist, in alarming the fears or exciting 
 the courage of his hero. On returning to the hall of his 
 ancestors, his attention is powerfully fixed on the grim 
 portraits which surround him. The parts which they 
 have respectively performed in the family history rise 
 to his mind : his own actions, whether good or evil, are 
 called up in contrast, and as the preserver or the destroyer 
 of his line, he stands as it were in judgment before them. 
 
 Fig. 27. 
 
 His imagination, thus excited by conflicting feelings, 
 transfers a sort of vitality to the canvas, and if the person- 
 ages do not " start from their frames," they will at least 
 bend upon him their frowns or their approbation. It is 
 in vain that he tries to evade their scrutiny. Wherever 
 he goes their eyes eagerly pursue him ; they will seem 
 even to look at him over their shoulders, and he will find 
 
1 94 LETTERS ON NATURAL MAGIC. 
 
 it impossible to shun their gaze but by quitting the 
 apartment. 
 
 As the spectator in this case changes his position in 
 a horizontal plane, the effect which we have described 
 is accompanied by an apparent diminution in the breadth 
 of the human face, from only seven or eight inches till 
 it disappears at a great obliquity. In moving, therefore, 
 from a front view to the most oblique view of the face, 
 the change in its apparent breadth is so slow that the 
 apparent motion of the head of the figure is scarcely 
 recognized as it follows the spectator. But if the per- 
 spective figure has a great breadth in a horizontal plane, 
 such as a soldier firing his musket, an artilleryman his 
 piece of ordnance, a bowman drawing his bow, or a lancer 
 pushing his spear, the apparent breadth of the figure 
 will vary from five to six feet or upwards till it disappears, 
 and therefore the change of apparent magnitude is suffi- 
 ciently rapid to give the figure the dreaded appearance 
 of turning round, and following the spectator. One of 
 the best examples of this must have been often observed 
 in the foreshortened figure of a dead body lying horizon- 
 tally, which has the appearance of following the observer 
 with great rapidity, and turning round upon the head as 
 the centre of motion. 
 
 The cause of this phenomenon is easily explained. 
 Let us suppose a portrait with its face and its eyes 
 directed straight in front, so as to look at the spectator. 
 Let a straight line be drawn through the tip of the nose 
 and half way between the eyes, which we shall call the 
 middle line. On each side of this middle line there will be 
 the same breadth of head, of cheek, of chin, and of neck, and 
 each iris will be in the middle of the whole of the eye. 
 If we now go to one side, the apparent horizontal breadth 
 of every part of the head and face will be diminished, 
 but the parts on each side of the middle line will be 
 
MOTION OF THE FEATURES OF A PORTRAIT. 195 
 
 diminished equally, and at any position, however oblique, 
 there will be the same breadth of face on each side of the 
 middle line, and the iris will be in the centre of the 
 whole of the eyeball, so that the portrait preserves all 
 the characters of a figure looking at the spectator, and 
 must necessarily do so wherever he stands. 
 
 This explanation might be illustrated by a picture 
 which represents three artillerymen, each firing a piece 
 of ordnance in parallel directions. Let the gun of the 
 middle one be pointed accurately to the eye of the specta- 
 tor, so that he sees neither its right side nor its left, nor 
 its upper nor its under side, but directly down its muzzle, 
 so that if there was an opening in the breech he would 
 see through it. In like manner the spectator will see the 
 left side of the gun on his left hand, and the right side of 
 the gun on his right hand. If the spectator now changes 
 his place, and takes ever such an oblique position, either 
 laterally or vertically, he must still see the same thing, 
 because nothing else is presented to his view. The gun 
 of the middle soldier must always point to his eye, and 
 the other guns to the right and left of him. They must 
 therefore all three seem to move as he moves, and follow 
 his eye in all its changes of place. The same observa- 
 tions are of course applicable to buildings and streets 
 seen in perspective. 
 
 In common portraits the apparent motion of the head 
 is generally rendered indistinct by the canvas being 
 imperfectly stretched, as the slightest concavity or con- 
 vexity entirely deforms the face when the obliquity is 
 considerable. The deception is therefore best seen when 
 the painting is executed on a very flat board, and in 
 colours sufficiently vivid to represent every line in the 
 face with tolerable distinctness at great obliquities. This 
 distinctness of outline is indeed necessary to a satisfactory 
 exhibition of this optical illusion. The most perfect 
 
196 LETTERS ON NATURAL MAGIC. 
 
 exhibition, indeed, that I ever saw of it was in the case 
 of a painting of a ship upon a sign-board, executed in 
 strongly gilt lines. It contained a view of the stern, and 
 side of a ship in the stocks, and, owing to the flatness 
 of the board and the brightness of the lines, the gradual 
 development of the figure from the most violent fore- 
 shortening at great obliquities till it attained its perfect 
 form, was an effect which surprised every person that saw 
 it. 
 
 The only other optical illusion which our limits will 
 permit us to explain, is the very remarkable experiment 
 of what may be truly called breathing light or darkness. 
 Let S be a candle where light falls at an angle of 56 45' 
 upon two glass plates A, B, placed close to each other, 
 and let the reflected rays A C, B D, fall at the same 
 angle upon two similar plates 0, D, but so placed that 
 the plane of reflection from the latter is at right angles 
 to the plane of reflection from the former. An eye placed 
 
 at E, and looking at the same time into the two plates 
 C and D, will see very faint images of the candle S, which 
 by a slight adjustment of the place may be made to dis- 
 appear almost wholly. Allowing the plate C to remain 
 as it is, change the position of D, till its inclination to 
 the ray B D is diminished about 3, or made nearly 
 53 11'. "When this is done, the image that had dis- 
 appeared on looking into D will be restored, so that the 
 
BREATHING LIGHT AND DARKNESS. 197 
 
 spectator at E. upon looking into the two mirrors C, D f 
 will see no light in C, because the candle has nearly 
 disappeared, while the candle is distinctly seen in D. 
 If, while the spectator is looking into these two 
 mirrors, either he or another person breathes upon them 
 gently and quickly, the breath will revive the ex- 
 tinguished image in C, and will extinguish the visible 
 image in D. The following is the cause of this singular 
 result. The light A C, B D, is polarized by reflection 
 from the plates A, B, because it is incident at the polariz- 
 ing angle of 56 45' for glass. When we breathe upon 
 the plates C, D, we form upon their surface a thin film 
 of water, whose polarizing angle is 53 11', so that if the 
 polarized rays A C, B D, fell upon the plates C, D, at 
 an angle of 53 11', the candle from which they proceeded 
 would not be visible, or they would not suffer reflection 
 from the plates C D. At all other angles the light would 
 be reflected and the candles visible. Now the plate D 
 is placed at an angle of 53 11', and C at an angle of 
 56 45', so that when a film of water is breathed upon 
 them the light will be reflected from the latter, and none 
 from the former : that is, the act of breathing upon the 
 plates will restore the invisible, and extinguish the visible 
 image. 
 
198 LETTERS ON NATURAL MAGIC. 
 
 LETTER VI. 
 
 Natural phenomena marked with the marvellous Spectre of the 
 Bracken described Analogous phenomena Aerial spectres seen 
 in Cumberland Fata Morgana in the Straits of Messina Objects 
 below the horizon raised and magnified by refraction Singular 
 example seen at Hastings Dover Castle seen through the hill on 
 which it stands Erect and inverted images of distant ships seen 
 in the air Similar phenomena seen in the Arctic regions En- 
 chanted coast Mr. Scoresby recognizes his father's ship by its 
 aerial image Images of cows seen in the air Inverted images 
 of horses seen in South America Lateral images produced by 
 refraction Ai'rial spectres by reflection Explanation of the pre- 
 ceding phenomena. 
 
 AMONG the wonders of the natural world which are every 
 day presented to us, without either exciting our surprise 
 or attracting our notice, some are occasionally displayed 
 which possess all the characters of supernatural phe- 
 nomena. In the names by which they are familiarly 
 known, we recognize the terror which they inspired, and 
 even now, when science has reduced them to the level of 
 natural phenomena, and developed the causes from which 
 they arise, they still retain their primitive importance, 
 and are watched by the philosopher with as intense 
 an interest as when they were deemed the immediate 
 effects of Divine power. Among these phenomena 
 we may enumerate the Spectre of the BrocJcen, the Fata 
 Morgana of the Straits of Messina, the Spectre Ships which 
 appear in the air, and the other extraordinary effects of the 
 Mirage.* 
 
 * la the Sanscrit, says Baron Humboldt, the phenomenon of the 
 Mirage is called Mriga Trichna, " thirst or desire of the antelope," no 
 
SPECTRE OF THE BKOCKEN. 199 
 
 The Brocken is the name of the loftiest of the Hartz 
 Mountains, a picturesque range which lies in the kingdom 
 of Hanover. It is elevated 3300 feet above the sea, and 
 commands the view of a plain seventy leagues in extent, 
 occupying nearly the two-hundredth part of the whole of 
 Europe, and animated with a population of above five mil- 
 lions of inhabitants. From the earliest periods of authentic 
 history, the Brocken has been the seat of the marvellous. 
 On its summits are still seen huge blocks of granite, 
 called the Sorcerer's Chair and the Altar. A spring of 
 pure water is known by the name of the Magic Fountain, 
 and the anemone of the Brocken is distinguished by the 
 title of the Sorcerer's Flower. These names are supposed 
 to have originated in the rites of the great Idol Cortho, 
 whom the Saxons worshipped in secret on the summit of 
 the Brocken, when Christianity was extending her 
 benignant sway over the subjacent plains. 
 
 As the locality of these idolatrous rites, the Brocken 
 must have been much frequented, and we can scarcely 
 doubt that the spectre which now so often haunts it at 
 sunrise must have been observed from the earliest times ; 
 but it is nowhere mentioned that this phenomenon was in 
 any way associated with the objects of their idolatrous 
 worship. One of the best accounts of the spectre of the 
 Brocken is that which is given by M. Haue, who saw it on 
 the 23rd of May, 1797. After having been on the summit 
 of the mountain no less than thirty times, he had at last 
 the good fortune of witnessing the object of his curiosity. 
 The sun rose about four o'clock in the morning through 
 a serene atmosphere. In the south-west, towards Achter- 
 
 doubt because this animal, Mriga, compelled by thirst, Trichua, 
 approaches those barren plains where, from the effect of unequal 
 refraction, he thinks he perceives the undulating surface of the 
 waters. Personal Narrative, vol. iii. p. 554. 
 
200 LETTERS ON NATURAL MAGIC. 
 
 mannshohe, a brisk west wind carried before it tlie trans- 
 parent vapours, which had not yet been condensed into 
 thick heavy clouds. About a quarter past four he went 
 towards the inn, and looked round to see whether the 
 atmosphere would afford him a free prospect towards the 
 south-west, when he observed at a very great distance, 
 towards Achtermannshohe, a human figure of a monstrous 
 size. His hat, having been almost carried away by a 
 violent gust of wind, he suddenly raised his hand to his 
 head, to protect his hat, and the colossal figure did the 
 same. He immediately made another movement by 
 
 Fig. 30. 
 
 bending his body, an action which was repeated by the 
 spectral figure. M. Haue was desirous of making further 
 experiments, but the figure disappeared. He remained, 
 however, in the same position, expecting its return, and 
 in a few minutes it again made its appearance on the 
 Achtermannshohe, when it mimicked his gestures as 
 before. He then called the landlord of the inn, and 
 having botli taken the same position which he had before, 
 they looked towards the Achtermannshohe but saw nothing. 
 In a very short space of time, however, two colossal 
 figures were formed over the above eminence, and after 
 bending their bodies and imitating the gestures of the 
 
AERIAL SPECTRES IN CUMBERLAND. 201 
 
 two spectators, they disappeared. Ketaining their posi- 
 tion, and keeping their eyes still fixed upon the same spot> 
 the two gigantic spectres again stood before them, and 
 were joined by a third. Every movement that they made 
 was imitated by the three figures, but the effect varied in 
 its intensity, being sometimes weak and faint, and at 
 other times strong and well defined. 
 
 In the year 1798 M. Jordan saw the same phenomenon 
 at sunrise, and under similar circumstances, but with less 
 distinctness and without any duplication of the figures.* 
 
 Phenomena perfectly analogous to the preceding, though 
 seen under less imposing circumstances, have been often 
 witnessed. "When the spectator sees his own shadow 
 opposite to the sun upon a mass of thin fleecy vapour 
 passing near him, it not only imitates all his movements, 
 but its head is distinctly encircled with a halo of light. 
 The aerial figure is often not larger than life, its size and 
 its apparent distance depending, as we shall afterwards 
 see, upon particular causes. I have often seen a similar 
 shadow when bathing in a bright summer's day in an 
 extensive pool of deep water. When the fine mud 
 deposited at the bottom of the pool is disturbed by 
 the feet of the bather, so as to be disseminated through 
 the mass of water in the direction of his shadow, his 
 shadow is no longer a shapeless mass formed upon the 
 bottom, but is a regular figure formed upon the floating 
 particles of mud, and having the head surrounded with 
 a halo, not only luminous, but consisting of distinct radi- 
 ations. 
 
 One of the most interesting accounts of aerial 'spectres 
 with which we are acquainted has been given by Mr. 
 James Clarke, in his Survey of the Lakes of Cumberland, 
 and the accuracy of this account was confirmed by the 
 
 * See J. F. Gmelin's Gottingischen Journal der Wissenchaften, 
 vol. i. part iii. 1798. 
 
 P 
 
202 LETTERS ON NATURAL MAGIC. 
 
 attestations of two of the persons by whom the pheno- 
 mena were first seen. On a summer's evening in the 
 year 1743, when Daniel Stricket, servant to John Wren 
 of Wilton Hall, was sitting at the door along with his 
 master, they saw the figure of a man with a dog pursuing 
 some horses along Souterfell side, a place so extremely 
 steep that a horse could scarcely travel upon it at all. 
 The figures appeared to run at an amazing pace, till they 
 got out of sight at the lower end of the Fell. On the 
 following morning Stricket and his master ascended the 
 steep side of the mountain, in the full expectation of 
 finding the man dead, and of picking up some of the shoes 
 of the horses, which they thought must have been cast 
 while galloping at such a furious rate. Their expecta- 
 tions, however, were disappointed. No traces either of 
 man or horse could be found, and they could not even 
 discover upon the turf the single mark of a horse's hoof. 
 These strange appearances, seen at the same time by two 
 different persons in perfect health, could not fail to make 
 a deep impression on their minds. They at first con- 
 cealed what they had seen, but they at length disclosed it, 
 and were laughed at for their credulity. 
 
 In the following year, on the 23rd June, 1744, Daniel 
 Stricket, who was then servant to Mr. Lancaster of Blake- 
 hills (a place near Wilton Hall, and both of which places 
 are only about half a mile from Souterfell), was walking, 
 about seven o'clock in the evening, a little above the 
 house, when he saw a troop of horsemen riding on 
 Souterfell side in pretty close ranks, and at a brisk pace. 
 Recollecting the ridicule that had been cast upon him the 
 preceding year, he continued to observe the ngures for 
 some time in silence ; but being at last convinced that 
 there could be no deception in the matter, he went to the 
 house and informed his master that he had something 
 curious to show him. They accordingly went out to- 
 
FATA MORGANA. 203 
 
 gether; but before Stricket had pointed out the place 
 Mr. Lancaster's son had discovered the aerial figures. 
 The family was then summoned to the spot, and the 
 phenomena were seen alike by them all. The equestrian 
 figures seemed to come from the lowest parts of Souterfell 
 and became visible at a place called Knott. They then 
 advanced in regular troops along the side of the Fell, till 
 they came opposite to Blakehills, when they went over 
 the mountain, after describing a kind of curvilineal path. 
 The pace at which the figures moved was a regular swift 
 walk, and they continued to be seen for upwards of two 
 hours, the approach of darkness alone preventing them 
 from being visible. Many troops were seen in succes- 
 sion ; and frequently the last but one in a troop quitted 
 his position, galloped to the front, and took up the same 
 pace with the rest. The changes in the figures were seen 
 equally by all the spectators, and the view of them was 
 not confined to the farm of Blakehills only, but they were 
 seen by every person at every cottage within the distance 
 of a mile, the number of persons who saw them amounting 
 to about twenty-six. The attestation of these facts, signed 
 by Lancaster and Stricket, bears the date of the 21st 
 July, 1744. 
 
 These extraordinary sights were received not only with 
 distrust but with absolute incredulity. They were not 
 even honoured with a place in the records of natural 
 phenomena, and the philosophers of the day were neither 
 in possession of analogous facts, nor were they acquainted 
 with those principles of atmospherical refraction upon 
 which they depend. The strange phenomena, indeed, of 
 the Fata Morgana, or the Castles of the Fairy Morgana, 
 had been long before observed, and had been described by 
 Kircher in the seventeenth century, but they presented 
 nothing so mysterious as the aerial troopers of Souterfell : 
 a nd the general characters of the two phenomena were so 
 
204 LETTERS ON NATURAL MAGIC. 
 
 unlike, that even a philosopher might have been excused 
 for ascribing them to different causes. 
 
 This singular exhibition has been frequently seen in 
 the Straits of Messina between Sicily and the coast of 
 Italy, and whenever it takes place, the people, in a state 
 of exultation, as if it were not only a pleasing but a lucky 
 phenomenon, hurry down to the sea, exclaiming Morgana, 
 Morgana. When the rays of the rising sun form an angle 
 of 45 on the sea of Eeggio, and when the surface of the 
 water is perfectly unruffled either by the wind or the 
 current, a spectator placed upon an eminence in the city, 
 and having his back to the sun and his face to the sea, 
 observes upon the surface of the water superb palaces 
 with their balconies and windows, lofty towers, herds and 
 flocks grazing in wooded valleys and fertile plains, armies 
 of men on horseback and on foot, with multiplied frag- 
 ments of buildings, such as columns, pilasters, and arches. 
 These objects pass rapidly in succession along the surface 
 of the sea during the brief period of their appearance. 
 The various objects thus enumerated are pictures of 
 palaces and buildings actually existing on shore, and the 
 living objects are of course only seen when they happen 
 to form a part of the general landscape. 
 
 If at the time that these phenomena are visible the 
 atmosphere is charged with vapour or dense exhalations, 
 the same objects which are depicted upon the sea will be 
 seen also in the air occupying a space which extends from 
 the surface to the height of twenty-five feet. These 
 images, however, are less distinctly delineated than the 
 former. 
 
 If the air is in such a state as to deposit dew, and is 
 capable of forming the rainbow, the objects will be seen 
 only on the surface of the sea, but they all appear fringed 
 with red, yellow, and blue light as if they were seen 
 through a prism. 
 
OBJECTS BELOW THE HORIZON MAGNIFIED. 205 
 
 In our own country, and in our own times, facts still 
 more extraordinary have been witnessed. From Hastings, 
 on the coast of Sussex, the cliffs on the French coast are 
 fifty miles distant, and they are actually hid by the con- 
 vexity of the earth ; that is, a straight line drawn from 
 Hastings to the French coast would pass through the sea. 
 On Wednesday, the 26th July, 1798, about five o'clock in 
 the afternoon, Mr. Latham, a Fellow of the Royal Society, 
 then residing at Hastings, was surprised to see a crowd of 
 people running to the seaside. Upon inquiry into the 
 cause of this, he learned that the coast of France could be 
 seen by the naked eye, and he immediately went down to 
 witness so singular a sight. He distinctly saw the cliffs 
 extending for some leagues along the French coast, and 
 they appeared as if they were only a few miles off. They 
 gradually appeared more and more elevated, and seemed 
 to approach nearer to the eye. The sailors with whom 
 Mr. Latham walked along the water's edge were at first 
 unwilling to believe in the reality of the appearance, but 
 they soon became so thoroughly convinced of it, that they 
 pointed out and named to him the different places which 
 they had been accustomed to visit, and which they con- 
 ceived to be as near as if they were sailing at a small 
 distance into the harbour. These appearances continued 
 for nearly an hour, the cliffs sometimes appearing brighter 
 and nearer, and at other times fainter and more remote. 
 Mr. Latham then went upon the eastern cliff or hill, 
 which is of considerable height, when, as he remarks, a 
 most beautiful scene presented itself to his view. He 
 beheld at once Dungeness, Dover Cliffs, and the French 
 coast all along from Calais, Boulogne, &c., to St. Vallery, 
 and, as some of the fishermen affirmed, as far west as 
 Dieppe. With the help of a telescope, the French 
 fishing-boats were plainly seen at anchor, and the dif- 
 ferent colours of the land upon the heights, together with 
 
206 LETTERS ON NATURAL MAGIC. 
 
 the buildings, were perfectly discernible. Mr. Latham 
 likewise states that the cape of land called Dungeness, 
 which extends nearly two miles into the sea, and is about 
 sixteen miles in a straight line from Hastings, appeared as 
 if quite close to it, and the vessels and fishing-boats which 
 were sailing between the two places appeared equally 
 near, and were magnified to a high degree. These curious 
 phenomena continued " in the highest splendour " till 
 past eight o'clock, although a black cloud had for some 
 time totally obscured the face of the sun. 
 
 A phenomenon no less marvellous was seen by Pro- 
 fessor Vince of Cambridge and another gentleman on the 
 Fig. 31. 
 
 6th August, 1806, at Ramsgate. The summits v w x y of 
 the four turrets of Dover Castle are usually seen over the 
 hill A B, upon which it stands, lying between Kamsgate 
 and Dover ; but on the day above mentioned, at seven 
 o'clock in the evening, when the air was very still and a little 
 hazy, not only were the tops v w x y of the four towers of 
 Dover Castle seen over the adjacent hill A B, but the whole 
 of the castle, m n r s, appeared as if it were situated on the 
 side of the hill next Ramsgate, and rising above the hill as 
 much as usual. This phenomenon was so very singular and 
 unexpected, that at first sight Dr. Vince thought it an illu- 
 sion ; but upon continuing his observations, he became 
 satisfied that it was a real image of the* castle. Upon 
 
INVERTED IMAGE OF A SHIP. 207. 
 
 this he gave a telescope to a person present, who, upon 
 attentive examination, saw also a very clear image of the 
 castle, as the Doctor had described it. He continued to 
 observe it for about twenty minutes, during which time 
 the appearance remained precisely the same, but rain 
 coming on, they were prevented from making any further 
 observations. Between the observers and the land from 
 which the hill rises, there was about six miles of sea, and 
 from thence to the top of the hill there was about the 
 same distance. Their own height above the surface of 
 the water was about seventy feet. 
 
 This illusion derived great force from the remarkable 
 circumstance, that the hill itself did not appear through 
 the image, as it might have been expected to do. The 
 image of the castle was very strong and well denned, and 
 though the rays from the hill behind it must undoubtedly 
 have come to the eye, yet the strength of the image of the 
 castle so far obscured the background, that it made no 
 sensible impression on the observers. Their attention 
 was, of course, principally directed to the image of the 
 castle; but if the hill behind had been at all visible, 
 Dr. Vince conceives that it could not have escaped their 
 observation, as they continued to look at it for a consider- 
 able time with a good telescope. 
 
 Hitherto our aerial visions have been seen only in their 
 erect and natural positions, either projected against the 
 ground or elevated in the air ; but cases have occurred in 
 which both erect and inverted images of objects have 
 been seen in the air, sometimes singly, sometimes com- 
 bined, sometimes when the real object was invisible, and 
 sometimes when a part of it had begun to show itself to 
 the spectator. 
 
 In the year 1793, Mr. Huddart, when residing at 
 Allonby, in Cumberland, perceived the inverted image of 
 a ship beneath the image, as shown in Fig. 32 ; but 
 
208 LETTERS ON NATURAL MAGIC. 
 
 Dr. Vince, who afterwards observed this phenomenon 
 
 under a greater variety of forms, found that the ship 
 
 Fig. 32. 
 
 which was here considered the real one, was only an erect 
 image of the real ship, which was at the time beneath the 
 horizon, and wholly invisible. 
 
 In August, 1798, Dr. Yince observed a great variety of 
 these aerial images of vessels approaching the horizon. 
 Fig. 33. 
 
ERECT AND INVERTED IMAGES OF SHIPS. 209 
 
 Sometimes there was seen only one inverted image above 
 the real ship, and this was generally the case when the 
 real ship was full in view. But when the real ship was 
 just beginning to show its topmast above the horizon, as 
 at A, Fig. 33, two aerial images of it were seen, one at B 
 inverted, and the other in its natural position at C. In 
 this case the sea was distinctly visible between the erect 
 and inverted images, but in other cases the hull of the 
 one image was immediately in contact with the hull of 
 the other. 
 
 Analogous phenomena were seen by Captain Scoresby 
 when navigating with the ship Baffin in the icy sea in the 
 immediate neighbourhood of West Greenland. On the 
 28th of June, 1820, he observed about eighteen sail of 
 ships at the distance of ten or fifteen miles. The sun 
 had shone during the day without the interposition of a 
 cloud, and his rays were peculiarly powerful. The inten- 
 sity of its light occasioned a painful sensation in the eyes, 
 while its heat softened the tar in the rigging of the ship, 
 and melted the snow on the surrounding ice with such 
 rapidity, that pools of fresh water were formed on almost 
 every place, and thousands of rills carried the excess into 
 the sea. There was scarcely a breath of wind : the sea 
 was as smooth as a mirror. The surrounding ice was 
 crowded together, and exhibited every variety, from the 
 smallest lumps to the most magnificent sheets. Bears 
 traversed the fields and floes in unusual numbers, and 
 many whales sported in the recesses and openings among 
 the drift ice. About six in the evening, a light breeze at 
 N.W. having sprung up, a thin stratus or ""fog bank," at 
 first considerably illuminated by the sun, appeared in the 
 same quarter, and gradually rose to the altitude of about 
 a quarter of a degree. At this time most of the ships 
 navigating at the distance of ten or fifteen miles began to 
 change their form and magnitude, and when examined by 
 
210 LETTERS ON NATURAL MAGIC. 
 
 a telescope from the masthead exhibited some extra- 
 ordinary appearances, which differed at almost every 
 point of the compass. One ship had a perfect image, as 
 dark and distinct as the original, united to its masthead 
 in a reverse position. Two others presented two distinct 
 inverted images in the air, one of them a perfect figure of 
 the original, and the other wanting the hull. Two or 
 three more were strangely "distorted, their masts appearing 
 of at least twice their proper height, the top-gallant mast 
 forming one-half of the total elevation, and other vessels 
 exhibited an appearance totally different from all the pre- 
 ceding, being as it were compressed in place of elongated. 
 Their masts seemed to be scarcely one-half of their 
 proper altitude, in consequence of which one would have 
 supposed that they were greatly heeled to one side, or in 
 the position called careening. Along with all the images 
 of the ships a reflection of the ice, sometimes in two 
 strata, also appeared in the air, and these reflections 
 suggested the idea of cliffs composed of vertical columns 
 of alabaster. 
 
 On the 15th, 16th, and 17th of the same month, 
 Mr. Scoresby observed similar phenomena, sometimes 
 extending continuously through half the circumference of 
 the horizon, and at other times appearing only in 
 detached spots in various quarters. The inverted images 
 of distant vessels were often seen in the air, while the ships 
 themselves were far beyond the reach of vision. Some 
 ships were elevated to twice their proper height, while 
 others were compressed almost to a line. Hummocks of 
 ice were surprisingly enlarged, and every prominent 
 object in a proper position was either magnified or 
 distorted. 
 
 But of all the phenomena witnessed by Mr. Scoresby, 
 that of the Enchanted Coast, as it may be called, must 
 have been the most remarkable. This singular effect was 
 
ENCHANTED COAST. 211 
 
 seen on the 18th July, when the sky was clear, and a 
 tremulous and perfectly transparent vapour was par- 
 ticularly sensible and profuse. At nine o'clock in the 
 morning, when the phenomenon was first seen, the ther- 
 mometer stood at 42 Fahr., but in the preceding evening 
 it must have been greatly lower, as the sea was in many 
 places covered with a considerable pellicle of new ice, a 
 circumstance which in the very warmest time of the year 
 must be considered as quite extraordinary, especially 
 when it is known that 10 farther to the north no freezing 
 of the sea at this season had ever before been observed. 
 Having approached on this occasion so near the unex- 
 plored shore of Greenland that the land appeared distinct 
 and bold, Mr. Scoresby was anxious to obtain a drawing 
 of it, but on making the attempt he found that the outline 
 was constantly changing, and he was induced to examine 
 the coast with a telescope, and to sketch the various 
 appearances which presented themselves. These are 
 shown, without any regard to their proper order, in 
 Fig. 34, which we shall describe in Mr. Scoresby's own 
 words : " The general telescopic appearance of the coast 
 was that of an extensive ancient city abounding with the 
 ruins of castles, obelisks, churches and monuments, with 
 other large and conspicuous buildings. Some of the hills 
 seemed to be surmounted by turrets, battlements, spires, 
 and pinnacles; while others, subjected to one or two 
 reflections, exhibited large masses of rock, apparently 
 suspended in the air, at a considerable elevation above 
 the actual termination of the mountains to which they 
 referred. The whole exhibition was a grand phantas- 
 magoria. Scarcely was any particular portion sketched 
 before it changed its appearance, and assumed the form of 
 an object totally different. It was perhaps alternately a 
 castle, a cathedral, or an obelisk ; then expanding hori- 
 zontally, and coalescing with the adjoining hills, united 
 
212 
 
 LETTERS ON NATURAL MAGIC. 
 
 the intermediate valleys, though some miles in width, by a 
 bridge of a single arch, of the most magnificent appearance 
 and extent. Notwithstanding these repeated changes, the 
 various figures represented in the drawing had all the 
 distinctness of reality ; and not only the different strata, 
 but also the veins of the rocks, with the wreaths of snow 
 occupying ravines and fissures, formed sharp ancl distinct 
 lines, and exhibited every appearance of the most 'perfect 
 solidity." 
 
 Fig. 34. 
 
 One of the most remarkable facts respecting aerial 
 images presented itself to Mr. Scoresby in a later voyage 
 which he performed to the coast of Greenland in 1822. 
 Having seen an inverted image of a ship in the air he 
 directed to it his telescope ; he was able to discover it to 
 be his father's ship, which was at the time below the 
 horizon. " It was," says he, "so well defined, that I could 
 distinguish by a telescope every sail, the general rig of 
 the ship, and its particular character ; insomuch, that I 
 confidently pronounced it to be my father's ship, the 
 Fame, which it afterwards proved to be ; though, on 
 comparing notes with my father, I found that our relative 
 position, at the time, gave a distance from one another 
 of very nearly thirty miles, being about seventeen miles 
 
AERIAL SPECTRES BY REFLECTION. 213 
 
 beyond the horizon, and some leagues beyond the limit of 
 direct vision. I was so struck with the peculiarity of the 
 circumstance, that I mentioned it to the officer of the 
 watch, stating my full conviction that the Fame was then 
 cruising in the neighbouring inlet." 
 
 Several curious effects of the mirage were observed by 
 Baron Humboldt during his travels in South America. 
 When he was residing at Cumana, he frequently saw the 
 islands of Picuita and Boracha suspended in the air, and 
 sometimes with an inverted image. On one occasion he 
 observed small fishing-boats swimming in the air, during 
 more than three or four minutes, above the well-defined 
 horizon of the sea, and when they were viewed through a 
 telescope, one of the boats had an inverted image 
 accompanying it in its movements. This distinguished 
 traveller observed similar phenomena in the barren 
 steppes of the Caraccas, and on the borders of the Orinoco, 
 where the river is surrounded by sandy plains. Little 
 hills and chains of hills appeared suspended in the air, 
 when seen from the steppes, at three or four leagues 
 distance. Palm trees standing single in the Llanos 
 appeared to be cut off at bottom, as if a stratum of air 
 separated them from the ground ; and, as in the African 
 desert, plains destitute of vegetation appeared to be rivers 
 or lakes. At the Mesa de Pavona M. Humboldt and 
 M. Bonpland saw cows suspended in the air at the distance 
 of 1000 toises, and having their feet elevated 3' 20" above 
 the soil. In this case the images were erect, but the 
 travellers learned from good authority that inverted 
 images of horses had been seen suspended in the air near 
 Calabozo. 
 
 In all these cases of aerial spectres the images were 
 directly above the real object; but a curious case was 
 observed by MM. Jurine and Soret on the 17th Sep- 
 tember, 1818, where the image of the vessel was on one 
 
214 LETTERS ON NATURAL MAGIC. 
 
 side of the real one. About 10 h P.M. a bark at the dis- 
 tance of about 4000 toises from Bellerive, on the lake of 
 Geneva, was seen approaching to Geneva, by the left 
 bank of the lake, and at the same time an image of the 
 sails was observed above the water, which, instead of 
 following the direction of the bark, separated from it, 
 and appeared to approach Geneva by the right bank of 
 the lake, the image moving from east to west, while the 
 bark moved from north to south. When the image first 
 separated from the bark they had both the same mag- 
 nitude, but the image diminished as it receded from it, 
 and was reduced to one-half when the phenomenon 
 disappeared. 
 
 A very unusual example of aerial spectres occurred to 
 Dr. A> P. Buchan while walking on the cliff about a mile 
 to the east of Brighton on the morning of the 28th 
 November, 1804. " While watching the rising of the 
 sun," says he, " I turned my eyes directly towards the 
 sea, just as the solar disc emerged from the surface of the 
 water, and saw the face of the cliff on which I was 
 standing represented precisely opposite to me at some 
 distance on the ocean. Calling the attention of my 
 companion to this appearance, we discerned our own 
 figures standing on the summit of the apparent opposite 
 cliff, as well as the representation of the windmill near at 
 hand. 
 
 " The reflected images were most distinct precisely 
 opposite to where we stood, and the false cliff seemed to 
 fade away, and to draw near to the real one, in proportion 
 as it receded towards the west. This phenomenon lasted 
 about ten minutes, or till the sun had risen nearly his 
 own diameter above the surface of the ocean. The whole 
 then seemed to be elevated into the air, and successively 
 disappeared, giving an impression very similar to that 
 which is produced by the drawing up of a drop scene in 
 
SHADOW IMAGE OF MOUNT .ETNA. 215 
 
 the theatre. The horizon was cloudy, or perhaps it 
 might with more propriety be said that the surface of the 
 sea was covered with a dense fog of many yards in height, 
 and which gradually receded before the rays of the sun." 
 
 An illusion of a different kind, though not less interest- 
 ing, is described by the Eeverend Mr. Hughes in his 
 Travels in Greece, as seen from the summit of Mount 
 ^Btna. " I must not forget to mention," says he, " one 
 extraordinary phenomenon which we observed, and for 
 which I have searched in vain for a satisfactory solution. 
 At the extremity of the vast shadow which Mtna, projects 
 across the island, appeared a perfect and distinct image of 
 the mountain itself elevated above the horizon, and 
 diminished as if viewed in a concave mirror. Where or 
 what the reflector could be which exhibited this image 
 I cannot conceive; we could not be mistaken in its 
 appearance, for all our party observed it, and we had been 
 prepared for it beforehand by our Catanian friends. It 
 remained visible about ten minutes, and disappeared as 
 the shadow decreased. Mr. Jones observed the same 
 phenomenon, as well as some other friends with whom I 
 conversed upon the subject in England." 
 
 It is impossible to study the preceding phenomena 
 without being impressed with the conviction that nature 
 is full of the marvellous, and that the progress of science 
 and the diffusion of knowledge are alone capable of 
 dispelling the fears which her wonders must necessarily 
 excite even in enlightened minds. When a spectre 
 haunts the couch of the sick, or follows the susceptible 
 vision of the invalid, a consciousness of indisposition 
 divests the apparition of much of its terror, while its 
 invisibility to surrounding friends soon stamps it with 
 the impress of a false perception. The spectres of the 
 conjurer too, however skilfully they may be raised, quickly 
 lose their supernatural character, and even the most 
 
216 LETTERS ON NATURAL MAGIC. 
 
 ignorant beholder regards the modern magician as but an 
 ordinary man, who borrows from the sciences the best 
 working implements of his art. But when, in the midst 
 of solitude, and in situations where the mind is undis- 
 turbed by sublunary cares, we see our own image de- 
 lineated in the air, and mimicking in gigantic perspective 
 the tiny movements of humanity ; when we see troops in 
 military array performing their evolutions on the very 
 face of an almost inaccessible precipice; when in the 
 eye of day a mountain seems to become transparent, and 
 exhibits on one side of it a castle which we know to exist 
 only on the other ; when distant objects, concealed by 
 the roundness of the earth, and beyond the cognizance of 
 the telescope, are actually transferred over the intervening 
 convexity and presented in distinct and magnified outline 
 to our accurate examination; when such varied and 
 striking phantasms are seen also by all around us, and 
 therefore appear in the character of real phenomena of 
 nature, our impressions of supernatural agency can only 
 be removed by a distinct and satisfactory knowledge of 
 the causes which gave them birth. 
 
 It is only within the last forty years that science has 
 brought these atmospherical spectres within the circle of 
 her dominion ; and not only are all their phenomena 
 susceptible of distinct explanation, but we can even re- 
 produce them on a small scale with the simplest elements 
 of our optical apparatus. 
 
 In order to convey a general idea of the causes of these 
 phenomena, let A B C k D, Fig. 35, be a glass trough 
 filled with water, and let a small ship be placed at S. 
 An eye situated about E, will see the topmast of the ship 
 S directly through the plate of glass B D. Fix a convex 
 lens a of short focus upon the plate of glass B B, and a 
 little above a straight line S E joining the ship and the eye ; 
 and immediately above the convex lens a place a concave 
 
EXPLANATION OF SPECTRE SHIPS. 
 
 217 
 
 one 6. The eye will now see through the convex lens a an 
 inverted image of the ship at S', and through the concave 
 lens 6, an erect image of the ship at S", representing in a 
 
 Fig. 35. 
 
 general way the phenomena shown in Fig. 33. But it 
 will be asked, where are the lenses in nature to produce 
 these effects ? This question is easily answered. If we 
 take a tin tube with glass plates at each end, and fill it 
 with water, and if we cool it on the outside with ice, it 
 will act like a concave lens when the cooling effect has 
 reached the axis ; and, on the other hand, if we heat the 
 same tube filled with water, on the outside, it will act as 
 a convex glass. In the first case the density of the water 
 diminishes towards the centre, and in the second it in- 
 creases towards the centre. The very same effects are 
 produced in the air, only a greater tract of air is neces- 
 sary for showing the effect produced, by heating and 
 cooling it unequally. If we now remove the lenses a, fc, 
 and hold a heated iron horizontally above the water in 
 the trough ABC, the heat will gradually descend, 
 expanding or rendering rarer the upper portions of the 
 fluid. If, when the heat has reached within a little of the 
 bottom, we look through the trough at the ship S in the 
 direction E S', we shall see an inverted image at S', and 
 an erect one at S", and if we hide from the eye at E all 
 
 Q 
 
218 LETTERS ON NATURAL MAGIC. 
 
 the ship S excepting the topmast, we shall have an exact 
 representation of the phenomenon in Fig. 33, The 
 experiment will succeed better with oil in place of water ; 
 and the same result may be obtained without heat, by 
 pouring clear syrup into the glass trough till it is nearly 
 one-third full, and then filling it up with water. The 
 water will gradually incorporate with the syrup, and 
 produce, as Dr. Wollaston has shown, a regular gradation 
 of density, diminishing from that of the pure syrup to 
 that of the pure water. Similar effects may be obtained 
 by using masses of transparent solids, such as glass, rock 
 salt, &c. 
 
 Now it is easy to conceive how the changes of density 
 which we can thus produce artificially may be produced 
 in nature. If in serene weather the surface of the sea is 
 much colder than the air of the atmosphere, as it fre- 
 quently is, and as it was to a very great degree during the 
 phenomena described by Mr. Scoresby, the air next the 
 sea will gradually become colder and colder, by giving 
 out its heat to the water ; and the air immediately above 
 will give out its heat to the cooler air immediately below 
 it, so that the air from the surface of the sea, to a con- 
 siderable height upwards, will gradually diminish in 
 density, and therefore must produce the very phenomena 
 we have described. 
 
 The phenomenon of Dover Castle, seen on the Eamsgate 
 side of the hill, was produced by the air being more dense 
 near the ground, and above the sea, than at greater heights, 
 and hence the rays proceeding from the castle reached the 
 eye in curved lines, and the cause of its occupying its 
 natural position on the hill, and not being seen in the air, 
 was that the top of the hill itself, in consequence of being 
 so near the castle, suffered the same change from the 
 varying density of the air, and therefore the castle and 
 the hill were equally elevated and retained their relative 
 
EXPLANATION OF SPECTRE SHIPS. 
 
 219 
 
 positions. The reason why the image of the castle and 
 the hill appeared erect was that the rays from the top and 
 bottom of the castle had not crossed before they reached 
 Kamsgate; but as they met at Eamsgate, an eye at a 
 greater distance from the castle, and in the path of the 
 rays, would have seen the image inverted. This will be 
 better understood from the annexed diagram, which re- 
 presents the actual progress of the rays, from a ship S P, 
 concealed from the observer at E by the convexity of the 
 
 Fig. 36. 
 
 earth P Q E. A ray proceeding from the keel of the 
 ship P is refracted into the curve line P c x c E, and a 
 ray proceeding from the topmast S is refracted in the 
 direction S d x d E, the two rays crossing at x, and pro- 
 ceeding to the eye E with the ray from the keel P 
 uppermost ; hence the ship must appear inverted as at s p. 
 Now if the eye E of the observer had been placed nearer 
 the ship as at x, before the rays crossed, as was the case 
 at Ramsgate, it would have seen an erect image of the 
 ship raised a little above the real ship S P. Bays S m, 
 S n, proceeding higher up in the air, are refracted in the 
 directions SmmE,SnwE, but do not cross before they 
 reach the eye, and therefore they afford the erect image 
 of the ship shown at s' p'. 
 
220 LETTERS ON NATURAL MAGIC. 
 
 The aerial troopers seen at Souterfell were produced by 
 the very same process as the spectre of Dover Castle, 
 having been brought by unequal refraction from one side 
 of the hill to the other. It is not our business to dis- 
 cover how a troop of soldiers came to be performing their 
 evolutions on the other side of Souterfell; but if there 
 was then no road along which they could be marching, it 
 is highly probable that they were troops exercising among 
 the hills in secret previous to the breaking out of the 
 Eebellion in 1745. 
 
 The image of the Genevese bark which was seen sailing 
 at a distance from the real one, arose from the same 
 cause as the images of ships in the air, with this difference 
 only, that in this case the strata of equal density were 
 vertical or perpendicular to the water, whereas in the 
 former cases they were horizontal or parallel to the 
 water. The state of the air which produced the lateral 
 image may be produced by a headland or island, or even 
 rocks, near the surface, and covered with water. These 
 headlands, islands, or sunken rocks being powerfully 
 heated by the sun in the daytime, will heat the air 
 immediately above them, while the adjacent air over the 
 sea will retain its former coolness and density. Hence 
 there will necessarily arise a gradation of density varying 
 in the same horizontal direction, or where the lines of 
 equal density are vertical. If we suppose the very same 
 state of the air to exist in a horizontal plane which exists 
 in a vertical plane, in Fig. 36, then the same images 
 would be seen in a horizontal line, viz., an inverted one at 
 s p, and an erect one at s p. In the case of the Genevese 
 bark the rays had not crossed before they reached the eye, 
 and therefore the image was an erect one. Had the real 
 Genevese bark been concealed by some promontory or 
 other cause from the observation of MM. Jurine and 
 Soret, they might have attached a supernatural character 
 
EXPLANATION OF PHENOMENA. 221 
 
 to the spectral image, especially if they had seen it 
 gradually decay, and finally disappear on the still and 
 unbroken surface of the lake. No similar fact had been 
 previously observed, and there were no circumstances 
 in the case to have excited the suspicion that it was 
 the spectre of a real vessel produced by unequal refrac- 
 tion. 
 
 The spectre of the Brocken and other phenomena of 
 the same kind have essentially a different origin from those 
 which arise from unequal refraction. They are merely 
 shadows of the observer projected on dense vapour or thin 
 fleecy clouds, which have the power of reflecting much 
 light. They are seen most frequently at sunrise, because 
 it is at that time that the vapours and clouds necessary 
 for their production are most likely to be generated ; and 
 they can be seen only when the sun is throwing his rays 
 horizontally, because the shadow of the observer would 
 otherwise be thrown either up in the air, or down upon 
 the ground. If there are two persons looking at the 
 phenomenon, as when M. Haue and the landlord saw it 
 together, each observer will see his own image most 
 distinctly, and the head will be more distinct than the 
 rest of the figure, because the rays of the sun will be 
 inore copiously reflected at a perpendicular incidence ; 
 and as from this cause the light reflected from the vapour 
 or cloud becomes fainter farther from the shadow, the 
 appearance of a halo round the head of the observer is 
 frequently visible. M. Haue mentions the extraordinary 
 circumstance of the two spectres of him and the land- 
 lord being joined by a third figure, but he unfortunately 
 does not inform us which of the two figures was doubled, 
 for it is impossible that a person could have joined their 
 party unobserved. It is very probable that the new 
 spectre forms a natural addition to the group, as we have 
 represented it in Fig. 30, and if this was the case, it could 
 
222 LETTERS ON NATURAL MAGIC. 
 
 only have been produced by a duplication of one of the 
 figures produced by unequal refraction. 
 
 The reflected spectre of Dr. Buchan standing upon 
 the cliff at Brighton arose from a cause to which we have 
 not yet adverted. It was obviously no shadow, for it is 
 certain, from the locality, that the rays of the sun fell 
 upon the face of the cliff and upon his person at an angle 
 of about 73 from the perpendicular, so as to illuminate 
 them strongly. Now there are t\vo ways in which such 
 an image may have been reflected, namely, either from 
 strata of air of variable density, or from a vertical stratum 
 of vapour, consisting of exceedingly minute globules of 
 water. Whenever light suffers refraction, either in 
 passing at once from, one medium into another, or from 
 one part of the same medium into another of different 
 density, a portion of it suffers reflection. If an object, 
 therefore, were strongly illuminated, a sufficiently distinct 
 image, or rather shadow of it, might be seen by reflection 
 from strata of air of different density. As the tem- 
 perature at which moisture is deposited in the atmosphere 
 varies with the density of the air, then at the same tem- 
 perature moisture might be depositing in a stratum of one 
 density, while no deposition is taking place in the adjacent 
 stratum of a different density. Hence there would exist as 
 it were in the air a vertical wall or stratum of minute 
 globules of water, from the surface of which a suffi- 
 ciently distinct image of a highly-illuminated object 
 might be reflected. That this is possible may be proved 
 by breathing upon glass. If the particles deposited upon 
 the glass are large, then no distinct reflection will take 
 place ; but if the particles be very small, we shall see a 
 distinct image formed by the surface of the aqueous film. 
 
 The phenomena of the Fata Morgana have been too 
 imperfectly described to enable us to offer a satisfactory 
 explanation of them. The aerial images are obviously 
 
EXPLANATION OF PHENOMENA. 223 
 
 those formed by unequal refraction. The pictures seen 
 on the sea may be either the aerial images reflected from 
 its surface, or from a stratum of dense vapour, or they 
 may be the direct reflections from the objects themselves. 
 The coloured images, as described by Minasi, have never 
 been seen in any analogous phenomena, and require to 
 be better described before they can be submitted to 
 scientific examination. 
 
 The representation of ships in the air by unequal 
 refraction has no doubt given rise in early times to those 
 superstitions which have prevailed in different countries 
 respecting " phantom ships," as Mr. Washington Irving 
 calls them, which always sail in the eye of the" wind, and 
 plough their way through the smooth sea, where there is 
 not a breath of wind upon its surface. In his beautiful 
 story of the storm ship, which makes its way up the 
 Hudson against wind and tide, this elegant writer has 
 finely embodied one of the most interesting supersti- 
 tions of the early American colonists. The Flying 
 Dutchman had in all probability a similar origin, and the 
 wizard beacon-keeper of the Isle of France, who saw in 
 the air the vessels bound to the island long before they 
 appeared in the offing, must have derived his power from 
 a diligent observation of the phenomena of nature. 
 
224 LETTERS ON NATURAL MAGIC. 
 
 LETTER VII. 
 
 Illusions depending on the ear Practised by the ancients Speaking 
 and singing heads of the ancients Exhibition of the invisible girl 
 described and explained Illusions arising from the difficulty of 
 determining the direction of sounds Singular example of this 
 illusion Nature of ventriloquism Exhibitions of some of the 
 most celebrated ventriloquists M. St. Gille Louis Brabant 
 M. Alexandre Captain Lyons account of Esquimaux ventrilo- 
 quists. 
 
 NEXT to the eye the ear is the most fertile source of our 
 illusions, and the ancient magicians seem to have been 
 very successful in turning to their purposes the doctrines 
 of sound. In the labyrinth of Egypt, which contained 
 twelve palaces and 1500 subterraneous apartments, the 
 gods were made to speak in a voice of thunder ; and Pliny, 
 in whose time this singular structure existed, informs us 
 that some of the palaces were so constructed that their 
 doors could not be opened without permitting the peals 
 of thunder from being heard in the interior. When 
 Darius Hystaspes ascended the throne, and allowed his 
 subjects to prostrate themselves before him as a god, the 
 divinity of his character was impressed upon his wor- 
 shippers by the bursts of thunder and flashes of lightning 
 which accompanied their devotion. History has of course 
 not informed us how these effects were produced ; but it 
 is probable that, in the subterraneous and vaulted apart- 
 ments of the Egyptian labyrinth, the reverberated sounds 
 arising from the mere opening and shutting of the doors 
 themselves afforded a sufficient imitation of ordinary 
 
SPEAKING AND SINGING HEADS. 225 
 
 thunder. In the palace of the Persian king, however, a 
 more artificial imitation is likely to have been employed, 
 and it is not improbable that the method used in our 
 modern theatres was known to the ancients. A thin 
 sheet of iron, three or four feet long, such as that used 
 for German stoves, is held by one corner between the 
 finger and the thumb, and allowed to hang freely by its 
 own weight. The hand is then moved or shaken hori- 
 zontally, so as to agitate the corner in a direction at right 
 angles to the surface of the sheet. By this simple process 
 a great variety of sounds will be produced, varying from 
 the deep growl of distant thunder to those loud and 
 explosive bursts which rattle in quick succession from 
 clouds immediately over our heads. The operator soon 
 acquires great power over this instrument, so as to be 
 able to produce from it any intensity and character of 
 sound that may be required. The same effect may be 
 produced by sheets of tin plate, and by thin plates of 
 mica ; but on account of their small size, the sound is 
 shorter and more acute. In modern exhibitions an admi- 
 rable imitation of lightning is produced by throwing the 
 powder of rosin, or the dust of lycopodium, through a flame, 
 and the rattling showers of rain which accompany these 
 meteors are well imitated by a well-regulated shower of 
 peas. 
 
 The principal pieces of acoustic mechanism used by 
 the ancients were speaking or singing heads, which were con- 
 structed for the purpose of representing the gods, or of 
 uttering oracular responses. Among these, the speaking 
 head of Orpheus, which uttered its responses at Lesbos, 
 is one of the most famous. It was celebrated not only 
 throughout Greece, but even in Persia, and it had the 
 credit of predicting, in the equivocal language of the 
 heathen oracles, the bloody death which terminated the 
 expedition of Cyrus the Great into Scythia. Odin, the 
 
226 
 
 LETTERS ON NATURAL MAGIC. 
 
 mighty magician of the north, who imported into Scan- 
 dinavia the magical arts of the east, possessed a speaking 
 head, said to be that of the sage Minos, which he had 
 enchased in gold, and which uttered responses that had all 
 the authority of a divine revelation. The celebrated 
 mechanic Gerbert, who filled the Papal chair A.D. 1000, 
 under the name of Sylvester II., constructed a speaking 
 head of brass. Albertus Magnus is said to have executed 
 a head in the thirteenth century, which not only moved 
 but spoke. It was made of earthenware, and Thomas 
 Aquinas is said to have been so terrified when he saw it, 
 that he broke it in pieces, upon which the mechanist 
 exclaimed, " There goes the labour of thirty years." 
 
 It has been supposed by some authors, that in the 
 ancient speaking-machines the deception was effected by 
 means of ventriloquism, the voice issuing from the juggler 
 himself ; but it is more probable that the sound was con- 
 veyed by pipes from a person in another apartment to the 
 mouth of the figure. Lucian, indeed, expressly informs 
 us that the impostor Alexander made his figure of JEscu- 
 lapius speak, by transmitting his voice through the gullet 
 of a crane to the mouth of the statue; and that this 
 method was general, appears from a passage in Theo- 
 doretus, who assures us that in the fourth century, when 
 Bishop Theophilus broke to pieces the statues at Alex- 
 andria, he found some which were hollow, and which were 
 so placed against a wall, that the priest could conceal 
 himself behind them, and address the ignorant spectators 
 through their mouths. 
 
 Even in modern times, speaking-machines have been 
 constructed on this principle. The figure is frequently a 
 mere head placed upon a hollow pedestal, which, in order 
 to promote the deception, contains a pair of bellows, a 
 sounding-board, a cylinder and pipes supposed to repre- 
 sent the organs of speech. In other cases these are dis- 
 
THE INVISIBLE GIRL. 227 
 
 pensed with, and a simple wooden head utters its sounds 
 through a speaking-trumpet. At the court of Charles II. 
 this deception was exhibited with great effect by one 
 Thomas Irson, an Englishman, and when the astonishment 
 had become very general, a popish priest was discovered 
 by one of the pages in an adjoining apartment. The 
 questions had been proposed to the wooden figure by 
 whispering into its ear, and this learned personage had 
 answered them all with great ability, by speaking through 
 a pipe in the same language in which the questions 
 were proposed. Professor Beckmann informs us that 
 children and women were generally concealed either in 
 the juggler's box, or in the adjacent apartment, and that 
 the juggler gave them every assistance by means of signs 
 previously agreed upon. When one of these exhibitions 
 was shown at Gottingen, the Professor was allowed, on 
 the promise of secrecy, to witness the process of deception. 
 He saw the assistant in another room, standing before the 
 pipe with a card in his hand, upon which the signs agreed 
 upon had been marked, and he had been introduced so 
 privately into the house that even the landlady was 
 ignorant of his being there. 
 
 An exhibition of the very same kind has been brought 
 forward in our own day, under the name of the Invisible 
 Girl; and as the mechanism employed was extremely 
 ingenious, and is well fitted to convey an idea of this 
 class of deceptions, we shall give a detailed description 
 of it. 
 
 The machinery, as contructed by M. Charles, is shown 
 in Fig. 37 in perspective, and a plan of it in Fig. 38. 
 The four upright posts A, A, A, A, are united at top 
 by a cross rail B, B, and by two similar rails at bottom. 
 Four bent wires a, a, a, a, proceeded from the top of these 
 posts, and terminated at c. A hollow copper ball M, 
 about a foot in diameter, was suspended from these 
 
228 
 
 LETTERS ON NATURAL MAGIC. 
 
 wires by four slender ribands b, 6, b, b, and into the 
 copper ball were fixed the extremities of four trumpets 
 T, T, T, T, with their mouths outwards. 
 
 Fig. 37. 
 
 The apparatus now described was all that was visible 
 to the spectator; and though fixed in one spot, yet it 
 had the appearance of a piece of separate machinery, 
 which might have occupied any other part of the room. 
 
 When one of the spectators was requested by the exhibitor 
 to propose some question, he did it by speaking into one 
 of the trumpets at T. An appropriate answer was then 
 
THE INVISIBLE GIKL. 229 
 
 returned from all the trumpets, and the sound issued 
 with sufficient intensity to be heard by an ear applied to 
 any of them, and yet it was so weak that it appeared to 
 come from a person of very diminutive size. Hence the 
 sound was supposed to come from an invisible girl, 
 though the real speaker was a full-grown woman. The 
 invisible lady conversed in different languages, sang 
 beautifully, and made the most lively and appropriate 
 remarks on the persons in the room. 
 
 This exhibition was obviously far more wonderful 
 than the speaking heads which we have described, as 
 the latter invariably communicated with a wall, or with 
 a pedestal through which pipes could be carried into the 
 next apartment. But the ball M and its trumpets com- 
 municated with nothing through which sound could be 
 conveyed. The spectator satisfied himself by examination 
 that the ribands 6, 6, were real ribands, which concealed 
 nothing, and which could convey no sound, and as he 
 never conceived that the ordinary piece of frame-work A B, 
 could be of any other use than its apparent one of support- 
 ing the sphere M, and defending it from the spectators, 
 he was left in utter amazement respecting the origin of 
 the sound, and his surprise was increased by the difference 
 between the sounds which were uttered and those of 
 ordinary speech. 
 
 Though the spectators were thus deceived by their 
 own reasoning, yet the process of deception was a very 
 simple one. In two of the horizontal railings A, A, 
 Fig. 38, opposite the trumpet mouths T, there was an 
 aperture communicating with a pipe or tube which went 
 to the vertical post B, and descending it, as shown at 
 T A A, Fig. 39, went beneath the floor// in the direc- 
 tion p. p, and entered the apartment N, where the invisible 
 lady sat. On the side of the partition about h, there 
 was a small hole, through which the lady saw what was 
 
230 LETTKRS ON NATURAL MAGIC. 
 
 going on in the exhibition room, and communications 
 were no doubt made to her by signals from the person 
 who attended the machine. When one of the spectators 
 asked a question by speaking into one of the trumpets T, 
 the sound was reflected from the mouth of the trumpet 
 back to the aperture at A, in the horizontal rail, Fig. 38, 
 
 Fig. 39. 
 
 and was distinctly conveyed along the closed tube into 
 the apartment N. In like manner the answer issued 
 from the aperture A, and being reflected back to the ear 
 of the spectator by the trumpet, he heard the sounds 
 with that change of character which they receive when 
 transmitted through a tube and then reflected to the 
 ear. 
 
 The surprise of the auditors was greatly increased by 
 the circumstance, that an answer was returned to ques- 
 tions put in a whisper, and also by the conviction that 
 nobody but a person in the middle of the audience could 
 observe the circumstances to which the invisible figure 
 frequently adverted. 
 
 Although the performances of speaking heads were 
 generally effected by the methods now described, yet 
 there is reason to think that the ventriloquist sometimes 
 presided at the exhibition, and deceived the audience 
 
ILLUSIONS OF SOUND. 231 
 
 by his extraordinary powers of illusion. There is no 
 species of deception more irresistible in its effects than 
 that which arises from the uncertainty with which we 
 judge of the direction and distance of sounds. Every 
 person must have noticed how a sound in their own ears 
 is often mistaken for some loud noise moderated by the 
 distance from which it is supposed to come ; and the 
 sportsman must have frequently been surprised at the 
 existence of musical sounds humming remotely in the 
 extended heath, when it was only the wind sounding in 
 the barrel of his gun. The great proportion of apparitions 
 that haunt old castles and apartments associated with 
 death exist only in the sounds which accompany them. 
 The imagination even of the boldest inmate of a place 
 hallowed by superstition, will transfer some trifling 
 sound near his own person to a direction and to a distance 
 very different from the truth, and the sound which other- 
 wise might have no peculiar complexion will derive 
 another character from its new locality. Spurning the 
 idea of a supernatural origin, he determines to unmask 
 the spectre, and grapple with it in its den. All the 
 inmates of the house are found to be asleep even the 
 quadrupeds are in their lair there is not a breath of 
 wind to ruffle the lake that reflects through the casement 
 the reclining crescent of the night ; and the massive 
 walls in which he is inclosed forbid the idea that he has 
 been disturbed by the warping of panelling or the 
 bending of partitions. His search is vain ; and he remains 
 master of his own secret, till he has another opportunity 
 of investigation. The same sound again disturbs him, 
 and, modified probably by his own position at the time, 
 it may perhaps appear to come in a direction slightly 
 different from the last. His searches are resumed, and 
 he is again disappointed. If this incident should recur 
 night #fter night with the same result ; if the sound 
 
232 LETTERS ON NATURAL MAGIC. 
 
 should appear to depend upon his own motions, or be 
 anyhow associated with himself, with his present feelings, 
 or with his past history, his personal courage will give 
 way, a superstitious dread, at which he himself perhaps 
 laughs, will seize his mind, and he will rather believe 
 that the sounds have a supernatural origin than that 
 they could continue to issue from a spot where he knows 
 there is no natural cause for their production. 
 
 I have had occasion to have personal knowledge of a 
 case much stronger than that which has now been put. 
 A gentleman, devoid of all superstitious feelings, and living 
 in a house free from any gloomy associations, heard night 
 after night in his bedroom a singular noise unlike any 
 ordinary sound to which he was accustomed. He had 
 slept in the same room for years without hearing it, and 
 he attributed it at first to some change of circumstances 
 in the roof or in the walls of the room, but after the 
 strictest examination no cause could be found for it. It 
 occurred only once in the night ; it was heard almost 
 every night, with few interruptions. It was over in an 
 instant, and it never took place till after the gentleman 
 had gone to bed. It was always distinctly heard by his 
 companion, to whose time of going to bed it had no 
 relation. It depended on the gentleman alone, and it 
 followed him into another apartment with another bed, 
 on the opposite side of the house. Accustomed to such 
 investigations, he made the most diligent but fruitless 
 search into its cause. The consideration that the sound 
 had a special reference to him alone, operated upon his 
 imagination, and he did not scruple to acknowledge that 
 the recurrence of the mysterious sound produced a 
 superstitious feeling at the moment. Many months 
 afterwards it was found that the sound arose from the 
 partial opening of the door of a wardrobe which was 
 within a few feet of the gentleman's head, and > which 
 
VENTRILOQUISM EXPLAINED. 233 
 
 had been taken into the other apartment. This wardrobe 
 was almost always opened before he retired to bed, and 
 the door being a little too tight, it gradually forced itself 
 open with a sort of dull sound, resembling the note of a 
 drum. As the door had only started half an inch out of 
 its place, its change of place never attracted attention. 
 The sound, indeed, seemed to come in a different direction, 
 and from a greater distance. 
 
 When sounds so mysterious in their origin are heard 
 by persons predisposed to a belief in the marvellous, 
 their influence over the mind must be very powerful. 
 An inquiry into their origin, if it is made at all, will be 
 made more in the hope of confirming than of removing 
 the original impression, and the unfortunate victim of 
 his own fears will also be the willing dupe of his own 
 judgment. 
 
 This uncertainty with respect to the direction of sound 
 is the foundation of the art of ventriloquism. If we place 
 ten men in a row at such a distance from us that they 
 are included in the angle within which we cannot judge 
 of the direction of sound, and if in a calm day each of 
 them speaks in succession, we shall not be able with 
 closed eyes to determine from which of the ten men any 
 of the sounds proceeds, and we shall be incapable of 
 perceiving that there is any difference in the direction of 
 the sounds emitted by the two uttermost. If a man and 
 a child are placed within the same angle, and if the man 
 speaks with the accent of a child without any correspond- 
 ing motion in his mouth or face, we shall necessarily 
 believe that the voice comes from the child : nay, if the 
 child is so distant from the man that the voice actually 
 appears to us to come from the man, we will still continue 
 in the belief that the child is the speaker ; and this con- 
 viction would acquire additional strength if the child 
 favoured the deception by accommodating its features and 
 
234 LETTERS ON NATURAL MAGIC. 
 
 gestures to the words spoken by the man. So powerful, 
 indeed, is the influence of this deception, that if a jack- 
 ass placed near the man were to open its mouth, and 
 shake its head responsive to the words uttered by his 
 neighbour, we would rather believe that the ass spoke 
 than that the sounds proceeded from a person whose 
 mouth was shut, and the muscles of whose face were in 
 perfect repose. If our imagination were even directed 
 to a marble statue or a lump of inanimate matter, as the 
 source from which we were to expect the sounds to issue, 
 we would still be deceived, and would refer the sounds 
 even to these lifeless objects. The illusion would be 
 greatly promoted if the voice were totally different in 
 its tone and character from that of the man from whom 
 it really comes ; and if he occasionally speak in his own 
 full and measured voice, the belief will be irresistible that 
 the assumed voice proceeds from the quadruped or from 
 the inanimate object. 
 
 When the sounds which are required to proceed from 
 any given object are such as they are actually calculated 
 to yield, the process of deception is extremely easy, and 
 it may be successfully executed even if the angle between 
 the real and the supposed directions of the sound is much 
 greater than the angle of uncertainty. Mr. Dugald 
 Stewart has stated some cases in which deceptions of this 
 kind were very perfect. He mentions his having seen 
 a person who, by counterfeiting the gesticulations of a 
 performer on the violin, while he imitated the music by 
 his voice, riveted the eyes of his audience on the instru- 
 ment, though every sound they heard proceeded from his 
 own mouth. The late Savile Carey, who imitated the 
 whistling of the wind through a narrow chink, told Mr. 
 Stewart that he had frequently practised this deception 
 in the corner of a coffee-house, and that he seldom 
 failed to see some of the company rise to examine the 
 
VENTRILOQUISM EXPLAINED. 235 
 
 tightness of the windows, while others, more intent on 
 their newspapers, contented themselves with putting on 
 their hats and buttoning their coats. Mr. Stewart 
 likewise mentions an exhibition formerly common in 
 some of the continental theatres, where a performer on 
 the stage displayed the dumb show of singing with his 
 lips and eyes and gestures, while another person unseen 
 supplied the music with his voice. The deception in 
 this case he found to be at first so complete as to impose 
 upon the nicest ear and the quickest eye ; but in the pro- 
 gress of the entertainment he became distinctly sensible 
 of the imposition, and sometimes wondered that it should 
 have misled him for a moment. In this case there can be 
 no doubt that the deception was at first the work of the 
 imagination, and was not sustained by the acoustic 
 principle. The real and the mock singer were too distant, 
 and when the influence of the imagination subsided, the 
 true direction of the sound was discovered. This detec- 
 tion of the imposture, however, may have arisen from 
 another cause. If the mock singer happened to change 
 the position of his head, while the real singer made no 
 corresponding change in his voice, the attentive spectator 
 would at once notice this incongruity, and discover the 
 imposition. 
 
 In many of the feats of ventriloquism the performer 
 contrives, under some pretence or other, to conceal his 
 face, but ventriloquists of great distinction, such as M. 
 Alexandre, practise their art without any such conceal- 
 ment. 
 
 Ventriloquism loses its distinctive character if its 
 imitations are not performed with a voice from the belly. 
 The voice, indeed, does not actually come from that 
 region, but when the ventriloquist utters sounds from the 
 larynx without moving the muscles of his face, he gives 
 them strength by a powerful action of the abdominal 
 
236 LETTERS ON NATUBAL MAGIC. 
 
 muscles. Hence he speaks by means of his belly, 
 although the throat is the real source from which the 
 sounds proceed. Mr. Dugald Stewart has doubted the 
 fact, that ventriloquists possess the power of fetching a 
 voice from within : he cannot conceive what aid could be 
 derived from such an extraordinary power ; and he con- 
 siders that the imagination, when seconded by such 
 powers of imitation as some mimics possess, is quite 
 sufficient to account for all the phenomena of ventriloquism 
 which he has heard. This opinion, however, is strongly 
 opposed by the remark made to Mr. Stewart himself by a 
 ventriloquist, " that his art would be perfect if it were 
 possible only to speak distinctly without any movement of 
 the lips at all." But, independent of this admission, it is 
 a matter of absolute certainty, that this internal power is 
 exercised by the true ventriloquist. In the account 
 which the Abbe Chapelle has given of the performances 
 of M. St. Gille and Louis Brabant, he distinctly states 
 that M. St. Gille appeared to be absolutely mute while he 
 was exercising his art, and that no change in his counte- 
 nance could be discovered.* He affirms also that the 
 countenance of Louis Brabant exhibited no change, and 
 that his lips were close and inactive. M. Eicherand, who 
 attentively watched the performances of M. Fitz-James, 
 assures us that during his exhibition there was a disten- 
 sion in the epigastric region, and that he could not long 
 continue the exertion without fatigue. 
 
 The influence over the human mind which the ventrilo- 
 quist derives from the skilful practice of his art is 
 greater than that which is exercised by any other species 
 of conjurer. The ordinary magician requires his theatre? 
 his accomplices, and the instruments of his art, and he 
 enjoys but a local sovereignty within the precincts of his 
 
 * Edinburgh Journal of Science, No. xviii. p. 254. 
 
VENTRILOQUISM OF M. ST. GILLE. 237 
 
 own magic circle. The ventriloquist, on the contrary, 
 has the supernatural always at his command. In the 
 open fields, as well as in the crowded city, in the private 
 apartment, as well as in the public hall, he can summon 
 up innumerable spirits ; and though the persons . of his 
 fictitious dialogue are not visible to the eye, yet they 
 are as unequivocally present to the imagination of his 
 auditors as if they had been shadowed forth in the silence 
 of a spectral form. In order to convey some idea of the 
 influence of this illusion, I shall mention a few well- 
 authenticated cases of successful ventriloquism. 
 
 M. St. Gille, a grocer of St. Germain-en-Laye, whose 
 performances have been recorded by the Abbe de la 
 Chapelle, had occasion to shelter himself from a storm in 
 a neighbouring convent, where the monks were in deep 
 mourning for a much-esteemed member of their community 
 who had been recently buried. While lamenting over 
 the tomb of their deceased brother the slight honours 
 which had been paid to his memory, a voice was suddenly 
 heard to issue from the roof of the choir, bewailing the 
 condition of the deceased in purgatory, and reproving the 
 brotherhood for their want of zeal. The tidings of this 
 supernatural event brought the whole brotherhood to the 
 church. The voice from above repeated its lamentations 
 and reproaches, and the whole convent fell upon their 
 faces, and vowed to make a reparation of their error. 
 They accordingly chanted in full choir a De Profundis, 
 during the intervals of which the spirit of the departed 
 monk expressed his satisfaction at their pious exercises. 
 The prior afterwards inveighed against modern scepticism 
 on the subject of apparitions, and M. St. Gille had great 
 difficulty in convincing the fraternity that the whole was 
 a deception. 
 
 On another occasion, a commission of the Royal 
 Academy of Sciences at Paris, attended by several 
 
238 LETTERS ON NATURAL MAGIC. 
 
 persons of the highest rank, met at St. Germain-en-Laye to 
 witness the performances of M. St. Gille. The real object 
 of their meeting was purposely withheld from a lady of 
 the party, who was informed that an aerial spirit had 
 lately established itself in the neighbourhood, and that the 
 object of the assembly was to investigate the matter. 
 When the party had sat down to dinner in the open air, 
 the spirit addressed the lady in a voice which seemed to 
 come from above their heads, from the surface of the 
 ground at a great distance, or from a considerable depth 
 under her feet. Having been thus addressed at intervals 
 during two hours the lady was firmly convinced of the 
 existence of the spirit, and could with difficulty be 
 undeceived. 
 
 Another ventriloquist, Louis Brabant, who had been 
 valet de chambre to Francis I., turned his powers to a 
 more profitable account. Having fallen in love with a 
 rich and beautiful heiress, he was rejected by her 
 parents as an unsuitable match for their daughter. On 
 the death of her father, Louis paid a visit to the widow, 
 and he had no sobner entered the house than she heard 
 the voice of her deceased husband addressing her 
 from above, "Give my daughter in marriage to Louis 
 Brabant, who is a man of large fortune and excellent 
 character. I endure the inexpressible torments of 
 purgatory for having refused her to him. Obey this 
 admonition, and give everlasting repose to the soul of 
 your poor husband." This awful command could not be 
 resisted, and the widow announced her compliance 
 with it. 
 
 As our conjurer, however, required money for the 
 completion of his marriage, he resolved to work upon the 
 fears of one Cornu, an old banker at Lyons, who had 
 amassed immense wealth by usury and extortion. 
 Having obtained an interview with the miser, he intro- 
 
VENTRILOQUISM OF M. BRABANT, ETC. 239 
 
 duced the subjects of demons and spectres and the 
 torments of purgatory, and, during an interval of silence, 
 the voice of the miser's deceased father was heard com- 
 plaining of his dreadful situation in purgatory, and 
 calling upon his son to rescue him from his sufferings 
 by enabling Louis Brabant to redeem the Christians that 
 were enslaved by the Turks. The awe-struck miser was 
 also threatened with eternal damnation if he did not thus 
 expiate his own sins ; but such was the grasp that the 
 banker took of his gold that the ventriloquist was 
 obliged to pay him another visit. On this occasion, not 
 only his father, but all his deceased relations appealed to 
 him in behalf of his own soul and theirs, and such was 
 the loudness of their complaints that the spirit of the 
 banker was subdued, and he gave the ventriloquist ten 
 thousand crowns to liberate the Christian captives. 
 When the miser was afterwards undeceived, he is said to 
 have been so mortified that he died of vexation. 
 
 The ventriloquists of the nineteenth century made great 
 additions to their art, and the performances of M. Fitz- 
 James and M. Alexandre, which must have been seen by 
 many of our countrymen, were far superior to those of 
 their predecessors. Besides the art of speaking by the 
 muscles of the throat and the abdomen, without moving 
 those of the face, these artists had not only studied with 
 great diligence and success the modifications which sounds 
 of all kinds undergo from distance, obstructions and other 
 causes, but had acquired the art of imitating them in the 
 highest perfection. The ventriloquist was therefore able 
 to carry on a dialogue in which the dramatis voces, as they 
 may be called, were numerous ; and when on the outside 
 of an apartment he could personate a mob with its infinite 
 variety of noise and vociferation. Their influence over an 
 audience was still further extended by a singular power 
 over the muscles of the body. M. Fitz-James actually 
 
240 LETTERS ON NATUKAL MAGIC. 
 
 succeeded in making the opposite or corresponding 
 muscles act differently from each other ; and while one 
 side of his face was merry and laughing, the other was 
 full of sorrow and in tears. At one moment he was tall, 
 thin, and melancholic, and after passing behind a screen 
 he came out "bloated with obesity and staggering with 
 fulness." M. Alexandre possessed the same power over 
 his face and figure, and so striking was the contrast of two 
 of these forms, that an excellent sculptor, Mr. Joseph, has 
 perpetuated them in marble. 
 
 This new acquirement of the ventriloquist enabled him, 
 in his own single person and with his own single voice, to 
 represent upon the stage a dramatic composition which 
 would have required the assistance of several actors. 
 Although only one character in the piece could be seen at 
 the same time, yet they all appeared during its perform- 
 ance, and the change of face and figure on the part of 
 the ventriloquist was so perfect that his personal identity 
 could not be recognised in the dramatis personce. This 
 deception was rendered still more complete by a par- 
 ticular construction of the dresses, which enabled the 
 performer to reappear in a new character after an interval 
 so short that the audience necessarily believed that it was 
 another person. 
 
 It is a curious circumstance that Captain Lyon found 
 among the Esquimaux of Igloolik ventriloquists of no 
 mean skill. There is much rivalry amongst the pro- 
 fessors of the art, who do not expose each other's secrets, 
 and their exhibitions derive great importance from the 
 rarity of their occurrence. The following account of one 
 of them is so interesting that we shall give the whole of 
 it in Captain Lyon's words. 
 
 " Amongst our Igloolik acquaintances were two females 
 and a few male wizards, of whom the principal was 
 Toolemak. This personage was cunning and intelligent, 
 
ESQUIMAUX VENTRILOQUISTS. 241 
 
 and, whether professionally, or from his skill in the 
 chase, but perhaps from both reasons, was considered by 
 all the tribe as a man of importance. As I invariably 
 paid great deference to his opinion on all subjects con- 
 nected with his calling, he freely communicated to me his 
 superior knowledge, and did not scruple to allow of my 
 being present [at his interviews with Tornga, or his 
 patron spirit. In consequence of this, I took an early 
 opportunity of requesting my friend to exhibit his skill 
 in my cabin. His old wife was with him, and by much 
 flattery and an accidental display of a glittering knife 
 and some beads, she assisted me in obtaining my request. 
 All light excluded, our sorcerer began chanting to his 
 wife with great vehemence, and she in return answered 
 by singing the Amna-aya, which was not discontinued 
 during the whole ceremony. As far as I could hear, he 
 afterwards began turning himself rapidly round, and in a 
 loud powerful voice vociferated for Tornga with great 
 impatience, at the same time blowing and snorting like a 
 walrus. His noise, impatience, and agitation increased 
 every moment, and he at length seated himself on the 
 deck, varying his tones, and making a rustling with his 
 clothes. Suddenly the voice seemed smothered, and was 
 so managed as to sound as if retreating beneath the 
 deck, each moment becoming more distant, and ultimately 
 giving the idea of being many feet below the cabin, when 
 it ceased entirely. His wife now, in answer to my 
 queries, informed me very seriously that he had dived, 
 and that he would send up Tornga. Accordingly, in 
 about half a minute, a distant blowing was heard very 
 slowly approaching, and a voice, which differed from 
 that at first heard, was at times mingled with the 
 blowing, until at length both sounds became distinct, 
 and the old woman informed me that Tornga was come 
 to answer my questions. I accordingly asked several 
 
242 LETTERS ON NATURAL MAGIC. 
 
 questions of the sagacious spirit, to each of which 
 inquiries I received an answer by two loud claps on 
 the deck, which I was given to understand were favour- 
 able. 
 
 " A very hollow, yet powerful voice, certainly much 
 different from the tones of Toolemak, now chanted for 
 some time, and a strange jumble of hisses, groans, shouts, 
 and gabblings like a turkey succeeded in rapid order. 
 The old woman sang with increased energy, and as I took it 
 for granted that this was all intended to astonish the 
 Kabloona, I cried repeatedly that I was very much 
 afraid. This, as I expected, added fuel to the fire, until 
 the poor immortal, exhausted by its own might, asked 
 leave to retire. 
 
 " The voice gradually sunk from our hearing as at first, 
 and a very indistinct hissing succeeded ; in its advance it 
 sounded like the tone produced by the wind on the bass 
 chord of an ^Elolian harp. This was soon changed to a 
 rapid hiss like that of a rocket, and Toolemak with a yell 
 announced his return. I had held my breath at the first 
 distant hissing, and twice exhausted myself, yet our con- 
 jurer did not once respire, and even his returning and 
 powerful yell was uttered without a previous stop or 
 inspiration of air. 
 
 "Light being admitted, our wizard, as might be ex- 
 pected, was in a profuse perspiration, and certainly much 
 exhausted by his exertions, which had continued for at 
 least half an hour. We now observed a couple of bunches, 
 each consisting of two stripes of white deer-skin and a 
 long piece of sinew, attached to the back of his coat. 
 These we had not seen before, and were informed that 
 they had been sewn on by Tornga while he was below."* 
 
 Captain Lyon had the good fortune to witness another 
 of Toolemak's exhibitions, and he was much struck with 
 * Private Journal of Captain G. F. Lyon, pp. 358, 361. 
 
ESQUIMAUX VENTBILOQUISTS. 243 
 
 the wonderful steadiness of the wizard throughout the 
 whole performance, which lasted an hour and a half. 
 He did not once appear to move, for he was so close to 
 the skin behind which Captain Lyon sat, that if he had 
 done so he must have perceived it. Captain Lyon did 
 not hear the least rustling of his clothes, or even dis- 
 tinguish his breathing, although his outcries were made 
 with great exertion.* 
 
 * Private Journal of Captain G. F. Lyon, p. 366. 
 
244 LETTERS ON NATURAL MAGIC. 
 
 LETTER VIII. 
 
 Musical and harmonic sounds explained Power of tweaking glasses 
 with the voice Musical sounds from the vibration of a column of 
 air And of solid bodies Kaleidophone Singular acoustic 
 figures produced on sand laid on vibrating plates of glass, and 
 on stretched membranes Vibration of fiat rulers, and cylinders 
 of glass Production of silence from two sounds Production of 
 darkness from two lights Explanation of these singular effects 
 Acoustic automaton Droz's bleating sheep Maillardefs singing 
 bird Vaucanson's flute-player His pipe and labor player 
 Baron Kempelen's talking engine Kratzenstein s speaking 
 machine Mr. Willis's researches. 
 
 AMONG the discoveries of modern science there are few 
 more remarkable than those which relate to the produc- 
 tion of harmonic sounds. We are all familiar with the 
 effects of musical instruments, from the deep-toned voice 
 of the organ to the wiry shrill of the Jew's harp. We sit 
 entranced under their magical influence, whether the ear 
 is charmed with the melody of their sounds, or the heart 
 agitated by the sympathies which they rouse. But 
 though we may admire their external form, and the skill 
 of the artist who constructed them, we never think of 
 inquiring into the cause of such extraordinary combina- 
 tions. 
 
 Sounds of all kinds are conveyed to the organ of hearing 
 through the air ; and if this element were to be destroyed 
 all nature would be buried in the deepest silence. Noises 
 of every variety, whether they are musical or discordant, 
 high or low, move through the air of our atmosphere at 
 the surface of the earth with a velocity of 1090 feet in a 
 
MUSICAL AND HARMONIC SOUNDS EXPLAINED. 245 
 
 second, or 765 miles per hour ; but in sulphurous acid 
 gas sound moves only through 751 feet in a second, while 
 in hydrogen gas it moves with the great velocity of 3000 
 feet. Along fluid and solid bodies its progress is still 
 more rapid. Through water it moves at the rate of 4708 
 feet in a second, through tin at the rate of 8175 feet, and 
 through iron, glass, and some kinds of wood, at the rate 
 of 18,530 feet. 
 
 When a number of single and separate sounds follow 
 each other in rapid succession, they produce a continued 
 sound, in the same manner as a continuous circle of light 
 is produced by whirling round a burning stick before the 
 eye. In order that the sound may appear a single one to 
 the ear, nearly sixteen separate sounds must follow one 
 another every second. When these sounds are exactly 
 similar, and recur at equal intervals, they form a musical 
 sound. In order to produce such sounds from the air, it 
 must receive at least sixteen equally distant impulses or 
 strokes in a second. The most common way of producing 
 this effect is by a string or wire A B, Fig. 40, stretched 
 between the fixed points A, B. If this string is taken by 
 the middle and pulled aside, or if it is suddenly struck, it 
 will vibrate between its two fixed points, as shown in the 
 figure, passing alternately on each side of its axis A B, 
 the vibrations gradually diminishing by the resistance of 
 the air till the string is brought to rest. Its vibrations, 
 however, may be kept up by drawing a rosined fiddle-bow 
 across it, and while it is vibrating it will give out a sound 
 corresponding to the rapidity of its vibrations, and arising 
 from the successive blows or impulses given to the air by 
 the string. This sound is called the fundamental sound 
 of the string, and its acuteness or sharpness increases 
 with the number of vibrations which the string performs 
 in a second. 
 
 If we now touch the vibrating string A' B' lightly with 
 
246 
 
 LETTERS ON NATURAL MAGIC. 
 
 the finger, or with a feather at the middle point C, Fig. 
 40, it will give out a more acute but fainter sound than 
 before, and while the extent of its vibrations is diminished, 
 their frequency is doubled. In like manner, if we touch 
 the string A" B", Fig. 40, at a point C, so that A" C is 
 one-third of A" B", the note will be still more acute, and 
 correspond to thrice the number of vibrations. All this 
 might have been expected, but the wonderful part of the 
 experiment is, that the vibrating string A' B' divides 
 itself at C into two parts A' C, C B', the part A' C 
 vibrating round A' and C as fixed points, and the part 
 C B' round C and B', but always so that the part A' C is 
 
 Fig. 40. 
 
 at the same distance on the one side of the axis A' B' as 
 at A m C, while the part C B is on the other side, as at 
 C n B. Hence the point C, being always pulled by equal 
 and opposite forces, remains at rest as if it were absolutely 
 fixed. This stationary point is called a node, and the 
 vibrating portions A' m C, C n B' loops. The very same 
 is true of the string A" B", the points C and D being 
 stationary points ; and upon the same principle a string 
 may be divided into any number of vibrating portions. 
 In order to prove that the string is actually vibrating in 
 these equal subdivisions, we have only to place a piece of 
 light paper with a notch in it on different parts of the 
 
MUSICAL SOUNDS FROM VIBRATION OF AIR. 247 
 
 string. At the nodes C and D it will remain perfectly at 
 rest, while at m or n in the middle of the loops it will be 
 thrown off or violently agitated. 
 
 The acute sounds given out by each of the vibrating 
 portions are called harmonic sounds, and they accompany 
 the fundamental sound of the string in the very same 
 manner, as we have already seen, that the eye sees the 
 accidental or harmonic colours while it is affected with 
 the fundamental colour. 
 
 The subdivision of the string, and consequently the 
 production of harmonic sounds, may be effected without 
 touching the string at all, and by means of a sympathetic 
 action conveyed by the air. If a string A B, for example, 
 Fig. 40, is at rest, and if a shorter string A" C, one- third 
 of its length, fixed at the two points A" and C is set 
 a-vibrating in the same room, the string A B will be set 
 a-vibrating in three loops like A" B", giving out the 
 same harmonic sounds as the small string A" C. 
 
 It is owing to this property of sounding bodies that 
 singers with great power of voice are able to break into 
 pieces a large tumbler glass, by singing close to it its 
 proper fundamental note ; and it is from the same sym- 
 pathetic communication of vibrations that two pendulum 
 clocks fixed to the same wall, or two watches lying upon 
 the same table, will take the same rate of going, though 
 they would not agree with one another if placed in sepa- 
 rate apartments. Mr. Ellicott even observed that the 
 pendulum of the one clock will stop that of the other, and 
 that the stopped pendulum will after a certain time resume 
 its vibrations, and in its turn stop the vibrations of the 
 other pendulum. 
 
 The production of musical sounds by the vibrations of 
 a column of air in a pipe is familiar to every person, but 
 the extraordinary mechanism by which it is effected is 
 known principally to philosophers. A column of air in a 
 
248 
 
 LETTERS ON NATURAL MAGIC. 
 
 pipe may be set a-vibrating by blowing over the open end 
 of it, as is done in Pan's pipes, or by blowing over a bole 
 in its side as in the flute, or by blowing through an aper- 
 ture called a reed, with a flexible tongue, as in the 
 clarionet. In order to understand the nature of this 
 vibration, let A B, Fig. 41, be a pipe or tube, and let us 
 place in it a spiral spring A B, in which the coil or spire 
 are at equal distances, each end of the spiral being fixed to 
 the end of the tube. This elastic spring may be supposed 
 to represent the air in the pipe, which is of equal density 
 throughout. If we take hold of the spring at m, and push 
 
 Fig. 41. 
 
 N A 
 
 
 
 the point m towards A and towards B in succession, it 
 will give us a good idea of the vibration of an elastic 
 column of air. When m is pushed towards A, the spiral 
 spring will be compressed or condensed, as shown at m A, 
 No. 2, while at the other end it will be dilated or rarefied, 
 as shown at m B, and in the middle of the tube it will 
 have the same degree of compression as in No. 1. When 
 the string is drawn to the other end of the tube B, the 
 spring will be, as in No. 3, condensed at the end B, and 
 dilated at the end A. Now when a column of air vibrates 
 in a pipe A B, the whole of it rushes alternately from B 
 to A, as in No. 2, and from A to B, as in No. 3, being 
 condensed at the end A, No. 2, and dilated or rarefied at 
 the end B, while in No. 3 it is rarefied at A and con- 
 
MUSICAL SOUNDS FROM VIBRATION OF AIR. 249 
 
 densed at B, preserving its natural density at the middle 
 point between A and B. In the case of the spring the 
 ends A B are alternately pushed outwards and pulled 
 inwards by the spring, the end A being pushed outwards 
 in No. 2, and B pulled inwards, while in No. 3 A is 
 pulled inwards and B pushed outwards. 
 
 That the air vijbrating in a pipe is actually in the state 
 now described may be shown by boring small holes in the 
 pipe, and putting over them pieces of a fine membrane. 
 The membrane opposite to the middle part between A 
 and B, where the particles of the air have the greatest 
 motion, will be violently agitated, while at points nearer 
 the ends A and B it will be less and less affected. 
 
 Let us now suppose two pipes A B, B C, to be joined 
 together as in Fig. 42, and to be separated by a fixed 
 
 N'2 
 
 partition at B ; and let a spiral spring be fixed in each. 
 Let the spring A B be now pushed to the end A, while the 
 spring B C is pushed to C, as in No, 1, and back again, as 
 in No. 2, but always in opposite directions ; then it is 
 obvious that the partition B is in No. 1 drawn in opposite 
 directions towards A and towards C, and always with 
 forces equal to each other, that is, when B is drawn 
 slightly towards A, which it is at the beginning of the 
 motion, it is also drawn slightly towards C, and when it 
 is drawn forcibly towards A, as it is at the end of the 
 motion of the spring, it is also drawn forcibly towards C. 
 If the partition B, therefore, is moveable, it will still 
 
250 LETTERS ON NATURAL MAGIC. 
 
 remain fixed during the opposite excursions of the spiral 
 springs : nay, if we remove the partition, and hook the 
 end of one spiral spring to the end of the other, the node 
 or point of junction will remain stationary during the 
 movements of the springs, because at every instant that 
 point is drawn by equal and opposite forces. If three, 
 four, or five spiral springs are joined in a similar manner, 
 we may conceive them all vibrating between their nodes 
 in the same manner. 
 
 Upon the very same principles we may conceive a long 
 column of air without partitions dividing itself into two, 
 three, or four smaller columns, each of which will vibrate 
 between its nodes in the same manner as the spiral spring. 
 At the middle point of each small vibrating column the 
 air will be of its natural density like that of the atmo- 
 sphere, while at the nodes B, &c., it will be in a state of 
 condensation and rarefaction alternately. 
 
 If, when the air is vibrating in one column in the pipe 
 A B, as in Fig. 41, Nos. 2, 3, we conceive a hole made in 
 the middle, the atmospheric air will not rush in to 
 disturb the vibration, because the air within the pipe and 
 without it has exactly the same density. Nay, if, instead 
 of a single hole, we were to cut a ring out of the pipe at 
 the middle point, the column would vibrate as before. 
 But if we bore a hole between the middle and one of the 
 ends, where the vibrating column must be either in a 
 state of condensation or rarefaction, the air must either 
 rush out or rush in, in order to establish the equilibrium. 
 The air opposite the hole will then be brought to the 
 state of the external air like that in the middle of the 
 pipe, it will become the middle of a vibrating column, 
 and the whole column of air, instead of vibrating as one, 
 will vibrate as two columns, each column vibrating with 
 twice the velocity, and yielding harmonic sounds along 
 with the fundamental sound of the whole columns, in the 
 
MUSICAL SOUNDS FROM VIBRATION OF SOLID BODIES. 251 
 
 same manner as we have already explained with regard to 
 vibrating strings. By opening other holes we may sub- 
 divide a vibrating column into any number of smaller 
 vibrating columns. The holes in flutes, clarionets, &c., 
 are made for this purpose. When they are all closed up 
 the air vibrates in one column, and by opening and 
 shutting the different holes in succession, the number of 
 vibrating columns is increased or diminished at pleasure, 
 and consequently the harmonic sounds will vary in a 
 similar manner. 
 
 Curious as these phenomena are, they are still surpassed 
 by those which are exhibited during the vibration of solid 
 bodies. A rod or bar of metal or glass may be made to 
 vibrate either longitudinally or laterally. 
 
 An iron rod will vibrate longitudinally like a column 
 of air if we strike it at one end in the direction of its 
 length, or rub it in the same direction with a wetted 
 finger, and it will emit the same fundamental note as a 
 column of air ten or eleven times as long, because sound 
 moves as much faster in iron than in air. When the iron 
 rod is thus vibrating along its length, the very same 
 changes which we have shown in Fig. 41, as produced in 
 a spiral spring or in a column of air, take place in the 
 solid metal. All its particles move alternately towards A 
 and towards B, the metal being in the one case condensed 
 at the end to which the particles move, and expanded at 
 the end from which they move, and retaining its natural 
 density in the middle of the rod. If we now hold this 
 rod in the middle, by the finger and thumb lightly 
 applied, and rub it in the middle either of A B or B C 
 with a piece of cloth sprinkled with powdered rosin, or 
 with a well-rosined fiddle-bow drawn across the rod, it 
 will divide itself into two vibrating portions A B, B C, 
 each of which will vibrate, as shown in Pig. 42, like the 
 two adjacent columns of air, the section of the rod, or the 
 
252 
 
 LETTERS ON NATURAL MAGIC. 
 
 particles which compose that section at B, being at perfect 
 rest. By holding the rod at any intermediate point be- 
 tween A and B, so that the distance from A to the finger 
 and thumb is one-third, one-fourth, one-fifth, &c., of the 
 whole length A C, and rubbing one of the divisions in 
 the middle, the rod will divide itself into 3, 4, 5, &c., 
 vibrating portions, and give out corresponding harmonic 
 sounds. 
 
 A rod of iron may be made to vibrate laterally or 
 transversely by fixing one end of it firmly as in a vice, 
 and leaving the other free, or by having both ends free or 
 both fixed. When a rod, fixed at one end and free at the 
 other, is made to vibrate, its mode of vibrating may bo 
 rendered evident to the eye ; and for the purpose of doing 
 this Mr. Wheatstone has contrived a curious instrument 
 called the KaleidopJione, which is shown in Fig. 43. It 
 
 Fig. 43. 
 
 consists of a circular base of wood A B, about nine inches 
 in diameter and one inch thick, and having four brass 
 sockets firmly fixed into it at C, D, E, and F. Into these 
 sockets are screwed four vertical steel rods, C, D, E, and 
 F, about 13 or 14 inches long, one being a square rod, 
 another a bent cylindrical one, and the other two cylin- 
 
ACOUSTIC FIGURES. 253 
 
 drical ones of different diameters. On the extremities of 
 these rods are fixed small quicksilvered glass beads, either 
 singly or in groups, so that when the instrument is 
 placed in the light of the sun or in that of a lamp, bright 
 images of the sun or candle are seen reflected on each 
 bead. If any of these rods is set a-vibrating, these 
 luminous images will form continuous and returning 
 curve lines in a state of constant variation, each different 
 rod giving curves of different characters. 
 
 The melodion, an instrument of great power, embracing 
 five octaves, operates by means of the vibrations of 
 metallic rods of unequal lengths, fixed at one end and 
 free at the other.* A narrow and thin plate of copper is 
 screwed to the free extremity of each rod, and at right 
 angles to its length ; and its surface is covered with a 
 small piece of felt impregnated with rosin. This narrow 
 band is placed near the circumference of a revolving 
 cylinder, and by touching the key it is made to descend 
 till it touches the revolving cylinder, and gives out its 
 sound. The sweetness and power of this instrument are 
 unrivalled, and such is the character of its tones, that 
 persons of a nervous temperament are often entirely 
 overpowered by its effects. 
 
 The vibrations of plates of metal or glass of various 
 forms exhibit a series of the most extraordinary phenomena 
 which are capable of being shown by very simple means. 
 These phenomena are displayed in an infinite variety of 
 regular figures assumed by sand, or fine lycopodium 
 powder, strewed over the surface of the glass plate. In 
 order to produce these figures, we must pinch or damp 
 the plate at one or more places, and when the sand is 
 strewed upon its surface it is thrown into vibrations by 
 drawing a fiddle-bow over different parts of its circum- 
 
 * See Edinburgh Encyclopaedia, Art. SCIENCE, CURIOSITIES IN, 
 vol. xvii. p. 563. 
 
254 
 
 LETTERS ON NATURAL MAGIC. 
 
 ference. The method of damping or pinching plates is 
 shown in Fig. 44. In No. 1 a square plate of glass A B, 
 ground smooth at its edges, is pinched by the finger and 
 thumb. In No. 2 a circular plate is held by the thumb 
 against the top c of a perpendicular rod, and damped by 
 the fingers at two different points of its circumference. 
 In No. 3 it is damped at three points of its circumference, 
 c and d, by the thumb and finger, and at e by pressing it 
 against a fixed obstacle a b. By means of a clamp like 
 that at No. 4, it may be damped at a greater number of 
 points. 
 
 Fiff. 44. 
 
 N'2, 
 
 If we take a square plate of glass, such as that shown in 
 Fig. 45, No. 1, and pinching it at its centre, draw the 
 fiddle-bow near one of its angles, the sand will accumulate 
 in the form of a cross, as shown in the figure, being 
 thrown off the parts of the plate that are in a state of 
 vibration, and settling in the nodes or parts which are at 
 rest. If the bow is drawn across the middle of one of the 
 edges, the sand will accumulate as in No, 2. If the plate 
 is pinched at N, No. 3, and the bow applied at F, and 
 perpendicular to A B, the sand will arrange itself in three 
 
ACOUSTIC FIGURES. 
 
 255 
 
 parallel lines, perpendicular to a fourth passing through 
 F and N. But if the point N, where it is pinched, is a 
 little farther from the edge than in No. 3, the parallel 
 lines will change into curves as in No. 4. 
 
 If the plate of glass is circular and pinched at its 
 centre, and also at a point of its circumference, and if the 
 bow is applied at a point 45 from the last point, the 
 figure of the sand will be as in Fig. 46. No. 1. If with 
 
 Fig 45. 
 
 the same plate, similarly pinched, the bow is drawn over 
 a part 30 from the pinched point of the circumference, 
 the sand will form six radii as in No. 2. When the 
 centre of the plate is left free, a different set of figures is 
 produced, as shown in No. 3 and No. 4. When the' plate 
 is pinched near its edge, and the bow applied 45 from 
 the point pinched, a circle of sand will pass through that 
 point, and two diameters of sand at right angles to each 
 other will be formed, as in No. 3. When a point of the 
 circumference is pressed against a fixed obstacle, and the 
 bow applied 30 from that point, the figure in No. 4 is 
 produced. 
 
256 
 
 LETTERS ON NATURAL MAGIC. 
 
 If, in place of a solid plate, we strew the sand over a 
 stretched membrane, the sand will form itself into figures, 
 even when the vibrations are communicated to the 
 membrane through the air. In order to make these 
 experiments, we must stretch a thin sheet of wet paper, 
 such as vegetable paper, over the mouth of a tumbler 
 glass with a footstalk, and fix it to the edges with glue. 
 When the paper is dry, a thin layer of dry sand is strewed 
 upon its surface. If we place this membrane upon a 
 
 No. 1. 
 
 Fig. 46. 
 
 No. 2. 
 
 No. 3. 
 
 No. 4. 
 
 table, and hold immediately above it, and parallel to the 
 membrane, a plate of glass vibrating so as to give any of 
 the figures shown in Fig. 46, the sand upon the membrane 
 will imitate exactly the figure upon the glass. If the 
 glass plate, in place of vibrating horizontally, is made to 
 vibrate in an inclined position, the figures on the mem- 
 brane will change with the inclination, and the sand will 
 assume the most curious arrangements. The figures thus 
 produced vary with the size of the membrane, with its 
 material, its tension, and its shape. When the same 
 
SILENCE FROM TWO SOUNDS. 257 
 
 figure occurs several times in succession, a breath upon 
 the paper will change its degree of tension and produce 
 an entirely new figure, which, as the temporary moisture 
 evaporates, will return to the original figure, through a 
 number of intermediate ones. The pipe of an organ at 
 the distance of a few feet, or the notes of a flute at the 
 distance of half a foot, will arrange the sand on the 
 membrane into figures which perpetually change with the 
 sound that is produced. 
 
 The manner in which flat rulers and cylinders of glass 
 perform their vibrations is very remarkable. If a glass 
 plate about twenty-seven inches long, six-tenths of an inch 
 broad, and six-hundredths of an inch thick, is held by the 
 edges between the finger and thumb, and has its lower 
 surface, near either end, rubbed with a piece of wet cloth, 
 sand laid upon its upper surface will arrange itself in 
 parallel lines at right angles to the length of the plate. 
 If the place of these lines is marked with a dot of ink, 
 and the other side of the glass ruler is turned upwards, 
 and the ruler made to vibrate as before, the sand will 
 now accumulate in lines intermediate between the former 
 lines, so that the motions of one-half the thickness of the 
 glass ruler are precisely the reverse of those of the cor- 
 responding parts of the other half. 
 
 As these singular phenomena have not yet been made 
 available by the scientific conjurer, we must be satisfied 
 with this brief notice of them ; but there is still one pro- 
 perty of sound, which has its analogy also in light, too 
 remarkable to be passed without notice. This property 
 has more of the marvellous in it than any result within 
 the wide range of the sciences. Two loud sounds may be 
 made to produce silence, and two strong lights may be made 
 to produce darkness ! 
 
 If two equal and similar strings, or the columns of air 
 in two equal and similar pipes, perform exactly 100 
 
258 LETTERS ON NATURAL MAGIC. 
 
 vibrations in a second, they will produce each equal 
 waves of sound, and these waves will conspire in gene- 
 rating an uninterrupted sound, double of either of the 
 sounds heard separately. If the two strings or the two 
 columns of air are not in unison, but nearly so, as in the 
 case where the one vibrates 100, and the other 101 times 
 in a second, then at the first vibration the two sounds 
 will form one of double the strength of either ; but the 
 one will gradually gain upon the other, till at the fiftieth 
 vibration it has gained half a vibration on the other. At 
 this instant the two sounds will destroy one another , and an 
 interval of perfect silence will take place. The sound 
 will instantly commence, and gradually increase till it 
 becomes loudest at the hundredth vibration, where the 
 two vibrations conspire in producing a sound double of 
 either. An interval of silence will again occur at the 
 150th, 250th, 350th vibration, or every second, while a 
 sound of double the strength of either will be heard at 
 the 200dth, SOOdth, and 400dth vibration. When the 
 unison is very defective, or when there is a great dif- 
 ference between the number of vibrations which the two 
 strings or columns of air perform in a second, the suc- 
 cessive sounds and intervals of silence resemble a rattle. 
 With a powerful organ the effect of this experiment is very 
 fine, the repetition of the sounds wow wow wow repre- 
 senting the doubled sound and the interval the silence 
 arising from the total extinction of the two separate sounds. 
 The phenomena corresponding to this in the case of 
 light are perhaps still more surprising. If a beam of red 
 light issues from a luminous point, and falls upon the 
 retina, we shall see distinctly the luminous object from 
 which it proceeds ; but if another pencil of red light 
 issues from another luminous point anyhow situated, 
 provided the difference between its distance and that of 
 the other luminous point from the point of the retina, on 
 
DARKNESS FROM TWO LIGHTS. 259 
 
 which the first beam fell, is the 258th thousandth part 
 of an inch, or exactly twice, thrice, four times, &c., that 
 distance; and if this second beam falls upon the same 
 point of the retina, the one light will increase the inten- 
 sity of the other, and the eye will see twice as much light 
 as when it received only one of the beams separately. 
 All this is nothing more than what might be expected 
 from our ordinary experience. But if the difference in 
 the distances of the two luminous points is only one-half 
 of the 258th thousandth part of an inch, or 1 J, 2-J, 3^, 4^ 
 times that distance, the one light will extinguish the other, 
 and produce absolute darkness. If the two luminous points 
 are so situated, that the difference of their distances from 
 the point of the retina is intermediate between 1 and 1 J, 
 or 2 and 2^, above the 258th thousandth part of an inch, 
 the intensity of the effect which they produce will vary 
 from absolute darkness to double the intensity of either 
 light. At 1J, 2J, 3J times, &c., the 258th thousandth of 
 an inch, the intensity of the two combined lights will be 
 equal only to one of them acting singly. If the lights, 
 in place of falling upon the retina, fall upon a sheet of 
 white paper, the very same effect will be produced ; a 
 black spot being produced in the one case, and a bright 
 white one in the other, and intermediate degrees of bright- 
 ness in intermediate cases. If the two lights are violet, 
 the difference of distances at which the preceding phe- 
 nomena will be produced will be the l7th thousandth 
 part of an inch, and it will be intermediate between the 
 258th and the 157th thousandth part of an inch, for the 
 intermediate colours. This curious phenomenon may be 
 easily shown to the eye, by admitting the sun's light into 
 a dark room through a small hole about the 40th or 50th 
 part of an inch in diameter, and receiving the light on a 
 sheet of paper. If we hold a needle or piece of slender 
 wire in this light, and examine its shadow, we shall find 
 
260 LETTERS ON NATURAL MAGIC. 
 
 that the snadow consists of bright and dark stripes suc- 
 ceeding each other alternately, the stripe in the very 
 middle or axis of the shadow being a bright one. The 
 rays of light which are bent into the shadow, and which 
 meet in the very middle of the shadow, have exactly the 
 same length of path, so that they form a bright fringe of 
 double the intensity of either ; but the rays which fall 
 upon a point of the shadow at a certain distance from the 
 middle have a difference in the length of their paths, 
 corresponding to the difference at which the lights destroy 
 each other, so that a black stripe is produced on each side 
 of the middle bright one. At a greater distance from the 
 middle, the difference becomes such as to produce a bright 
 stripe, and so on, a bright and a dark stripe succeeding 
 each other to the margin of the shadow. 
 
 The explanation which philosophers have given of these 
 strange phenomena is very satisfactory, and may be easily 
 understood. When a wave is made on the surface of a 
 still pool of water, by plunging a stone into it, the wave 
 advances along the surface, while the water itself is never 
 carried forward, but merely rises into a height and falls 
 into a hollow, each portion of the surface experiencing an 
 elevation and a depression in its turn. If we suppose two 
 waves equal and similar to be produced by two sepa- 
 rate stones, and if they reach the same spot at the same 
 time, that is, if the two elevations should exactly coincide, 
 they would unite their effects and produce a wave twice 
 the size of either ; but if the one wave should be just so 
 far before the other that the hollow of the one coincided 
 with the elevation of the other, and the elevation of the 
 one with the hollow of the other, the two waves would 
 obliterate or destroy one another, the elevation as it were 
 of the one filling up half the hollow of the other, and the 
 hollow of the one taking away half the elevation of the 
 other, so as to reduce the surface to a level. These 
 
DARKNESS FROM TWO LIGHTS. 261 
 
 effects will be actually exhibited by throwing two equal 
 stones into a pool of water, and it will be seen that there 
 are certain lines of a hyperbolic form where the water is 
 quite smooth, in conseqence of the equal waves obliterating 
 one another, while in other adjacent parts the water is 
 raised to a height corresponding to both the waves united. 
 
 In the tides of the ocean, we have a fine example of the 
 same principle. The two immense waves arising from 
 the action of the sun and moon upon the ocean produce 
 our spring-tides by their combination, or when the ele- 
 vations of each coincide, and our neap-tides, when the 
 elevation of the one wave coincides with the depression 
 of the other. If the sun and moon had exerted exactly 
 the same force upon the ocean, or produced tide waves 
 of the same size, then our neap-tides would have disap- 
 peared altogether, and the spring-tide would have been 
 a wave double of the wave produced by the sun and moon 
 separately. An example of the effect of the equality 
 of the two waves occurs in the port of Batsha, where the 
 two waves arrive by channels of different lengths, and 
 actually obliterate each other. 
 
 Now, as sound is produced by undulations or waves in 
 the air, and as light is supposed to be produced by waves 
 or undulations in an ethereal medium, filling all nature, 
 and occupying the pores of transparent bodies, the suc- 
 cessive production of sound and silence, by two loud 
 sounds, or of light and darkness by two bright lights, 
 may be explained in the very same manner as we have 
 explained the increase and the obliteration of waves 
 formed on the surface of water. If this theory of light 
 be correct, then the breadth of a wave of red light will 
 be the 258th thousandth part of an inch, the breadth of 
 a wave of green light the 207th thousandth part of an 
 inch, and the breadth of a wave of violet light the 157th 
 thousandth part of an inch. 
 
262 LETTERS ON NATURAL MAGIC. 
 
 Among the wonders of modern skill, we must enumerate 
 those beautiful automata by which the motions and actions 
 of man and other animals have been successfully imitated. I 
 shall therefore describe at present some of the most remark- 
 able acoustic automata, in which the production of musical 
 and vocal sounds has been the principal object of the artist- 
 
 Many very ingenious pieces of acoustic mechanism 
 have been from time to time exhibited in Europe. The 
 celebrated Swiss mechanist, M. le Droz, constructed for 
 the King of Spain the figure of a sheep, which imitated 
 in the most perfect manner the bleating of that animal, 
 and likewise the figure of a dog watching a basket of fruit, 
 which, when any of the fruit was taken away, never 
 ceased barking till it was replaced. 
 
 The singing-bird of M. Maillarclet, which he exhibited 
 in Edinburgh many years ago, is still more wonderful.* 
 An oval box, about three inches long, was set upon the 
 table, and in an instant the lid flew up, and a bird of the 
 size of the humming-bird, and of the most beautiful 
 plumage, started from its nest. After fluttering its wings, 
 it opened its bill and performed four different kinds of 
 the most beautiful warbling. It then darted down into 
 its nest, and the lid closed upon it. The moving power 
 in this piece of mechanism is said to have been springs 
 which continued their action only four minutes. As 
 there was no room, within so small a figure, for accom- 
 modating pipes to produce the great variety of notes which 
 were warbled, the artist used only one tube, and produced 
 all the variety of sounds by shortening and lengthening 
 it with a moveable piston. 
 
 Ingenious as these pieces of mechanism are, they sink 
 into insignificance when compared with the machinery of 
 M. Vaucanson, which had previously astonished all 
 
 * A similar piece of mechanism had been previously made by 
 M. le Droz. 
 
VAUCANSON'S FLUTE-PLAYER. 263 
 
 Europe. His two principal automata were the flute- 
 player, and the pipe and tabor player. The flute-player 
 was completed in 1736, and wherever it was exhibited it 
 produced the greatest sensation. When it came to Paris 
 it was received with great suspicion. The French savans 
 recollected the story of M. Eaisin, the organist of Troyes, 
 who exhibited an automaton player upon the harpsichord, 
 which astonished the French court by the variety of its 
 powers. The curiosity of the King could not be restrained, 
 and in consequence of his insisting upon examining the 
 mechanism, there was found in the figure a pretty little 
 musician five years of age. It was natural, therefore, 
 that a similar piece of mechanism should be received with 
 some distrust ; but this feeling was soon removed by 
 M. Vaucanson, who exhibited and explained to a com- 
 mittee of the Academy of Sciences the whole of the 
 mechanism. This learned body was astonished at the 
 ingenuity which it displayed ; and they did not hesitate 
 to state, that the machinery employed for producing the 
 sounds of the flute performed in the most exact manner 
 the very operations of the most expert flute-player, and 
 that the artist had imitated the effects produced, and the 
 means employed by nature, with an accuracy which had 
 exceeded all expectation. In 1738, M. Vaucanson pub- 
 lished a memoir, approved of by the Academy, in which 
 he gave a full description of the machinery employed, 
 and of the principles of its- construction. Following this 
 memoir, I shall therefore attempt to give as popular a 
 description- of the automaton as can be done without 
 lengthened details and numerous figures. 
 
 The body of the flute-player was about 5-J feet high, and 
 was placed upon a piece of rock, surrounding a square 
 pedestal 4i feet high by three and a half wide. When 
 the panel which formed the front of the pedestal was 
 opened, there was seen on the right a clock movement, 
 
264 LETTERS ON NATURAL MAGIC. 
 
 which, by the aid of several wheels, gave a rotatory motion 
 to a steel axis about 2J feet long, having cranks at six 
 equidistant points of its length, but lying in different 
 directions. To each crank was attached a cord, which 
 descended and was fixed by its other end to the upper 
 board of a pair of bellows, 2J feet long and six inches 
 wide. Six pair of bellows arranged along the bottom of 
 the pedestal were then wrought, or made to blow in 
 succession, by turning the steel axis. 
 
 At the upper face of the pedestal, and upon each pair of 
 bellows, is a double pulley, one of whose rims is 3 inches 
 in diameter, and the other 1J. The cord which proceeds 
 from the crank coils round the smallest of these pulleys, 
 and that which is fixed to the upper board of the bellows 
 goes round the larger pulley. By this means the upper 
 board of the bellows is made to rise higher than if the 
 cords went directly from them to the cranks. 
 
 Bound the larger rims of three of these pulleys, viz., 
 those on the right hand, there are coiled three cords, 
 which, by means of several smaller pulleys, terminate in 
 the upper boards of other three pairs of bellows placed on 
 the top of the box. 
 
 The tension of each cord when it begins to raise the 
 board of the bellows to which it is attached, gives motion 
 to a lever placed above it between the axis and the double 
 pulley in the middle and lower region of the box. The 
 other end of this lever keeps open the valve in the lower 
 board of the bellows, and allows the air to enter freely, 
 while the upper board is rising to increase the capacity of 
 the bellows. By this means there is not only power 
 gained, in so far as the air gains easier admission through 
 the valve, but the fluttering noise produced by the action 
 of the air upon the valves is entirely avoided, and the nine 
 pair of bellows are wrought with great ease, and without 
 any concussion or noise. 
 
VAUCANSON'S FLUTE-PLAYER. 265 
 
 These nine bellows discharge their wind into three 
 different and separate tubes. Each tube receives the wind 
 of three bellows, the upper boards of one of the three pair 
 being loaded with a weight of four pounds, those of the 
 second three pair with a weight of two pounds, and those 
 of the other three pair with no weight at all. These three 
 tubes ascended through the body of the figure, and termi- 
 nated in three small reservoirs placed in its trunk. These 
 reservoirs were thus united into one, which, ascending into 
 the throat, formed by its enlargement the cavity of the 
 mouth terminated by two small lips, which rested upon 
 the hole of the flute. These lips had the power of 
 opening more or less, and by a particular mechanism they 
 could advance or recede from the hole in the flute. 
 Within the cavity of the mouth there is a small moveable 
 tongue for opening and shutting the passage for the wind 
 through the lips of the figure. 
 
 The motions of the fingers, lips, and tongue, of the 
 figure were produced by means of a revolving cylinder 
 thirty inches long, and twenty-one in diameter. By 
 means of pegs and brass staples fixed in fifteen different 
 divisions in its circumference, fifteen different levers, 
 similar to those in a barrel-organ, were raised and 
 depressed. Seven of these regulated the motions of the 
 seven fingers for stopping the holes of the flute, which 
 they did by means of steel chains rising through the body 
 and directed by pulleys to the shoulder, elbow, and fingers. 
 Other three of the levers, communicating with the valves 
 of the three reservoirs, regulated the ingress of the air, so 
 as to produce a stronger or a weaker tone. Another lever 
 opened the lips so as to give a free passage to the air, and 
 another contracted them for the opposite purpose. A third 
 lever drew them backwards from the orifice of the flute, 
 and a fourth pushed them forward. The remaining lever 
 enabled the tongue to stop up the orifice of the flute. 
 
266 LETTERS ON NATURAL MAGIC. 
 
 Such is a very brief view of the general mechanism by 
 which the requisite motions of the flute-player were 
 produced. The airs which it played were probably equal 
 to those executed by a living performer, and its construc- 
 tion, as well as its performances, continued for many years 
 to delight and astonish the philosophers and musicians of 
 Europe. 
 
 Encouraged by the success of this machine M. Vaucan- 
 son exhibited in 1741 other automata, which were equally, 
 if not more, admired. One of these was the automaton 
 duck, which performed all the motions of that animal, and 
 not only ate its food, but digested it ; * and the other was 
 his pipe and tabor-player, a piece of mechanism which re- 
 quired all the resources of his fertile genius. Having 
 begun this machine before he was aware of its peculiar 
 difficulties, he was often about to abandon it in despair, 
 but his patience and his ingenuity combined enabled him 
 not only to surmount every difficulty, but to construct an 
 automaton which performed complete airs, and greatly ex- 
 celled the most esteemed performers on the pipe and tabor. 
 
 The figure stands on a pedestal, and is- dressed like a 
 dancing shepherd. He holds in one hand a flageolet, and 
 in the other the stick with which he beats the tambourin 
 as an accompaniment to the airs of the flageolet, about 
 twenty of which it is capable of performing. The 
 flageolet has only three holes, and the variety of its tones 
 depends principally on a proper variation of the force of 
 the wind, and on the different degrees with which the 
 orifices are covered. These variations in the force of the 
 wind required to be given with a rapidity which the ear 
 can scarcely follow, and the articulation of the tongue was 
 required for the quickest notes, otherwise the effect was 
 far from agreeable. As the human tongue is not capable 
 of giving the requisite articulations to a rapid succession 
 * See Letter XL 
 
KEATZENSTEIN'S TALKING AUTOMATON. 267 
 
 of notes, and generally slurs over one-half of them, the 
 automaton was thus able to excel the best performers, as 
 it played complete airs with articulations of the tongue at 
 every note. 
 
 In constructing this machine M. Vaucanson observed 
 that the flageolet must be a most fatiguing instrument for 
 the human lungs, as the muscles of the chest must make 
 an effort equal to 56 pounds in order to produce the 
 highest notes. A single ounce was sufficient for the 
 lowest notes, so that we may, from this circumstance, 
 form an idea of the variety of intermediate effects required 
 to be produced. 
 
 While M. Vaucanson was engaged in the construction 
 of these wonderful machines, his mind was filled with the 
 strange idea of constructing an automaton containing the 
 whole mechanism of the circulation of the blood. From 
 some birds which he made he was satisfied of its practica- 
 bility ; but as the whole vascular system required to be made 
 of elastic gum or caoutchouc, it was supposed that it could 
 only be executed in the country where the caoutchouc-tree 
 was indigenous. Louis XVI. took a deep interest in the 
 execution of this machine. It was agreed that a skilful 
 anatomist should proceed to Guiana to superintend the 
 construction of the blood-vessels, and the King had not 
 only approved of, but had given orders for, the voyage. 
 Difficulties, however, were thrown in the way : Vaucanson 
 became disgusted, and the scheme was abandoned. 
 
 The two automata which we have described were 
 purchased by Professor Bayreuss of Helmstadt; but we 
 have not been able to learn whether or not they still 
 exist. 
 
 Towards the end of the nineteenth century a bold and 
 almost successful attempt was made to construct a talking 
 automaton. In the year 1779, the Imperial Academy of 
 Sciences at St. Petersburgh proposed as the subject of one 
 
268 
 
 LETTERS ON NATURAL MAGIC. 
 
 of their annual prizes an inquiry into the nature of the 
 vowel sounds A, E, I, O and U, and the construction of 
 an instrument for artificially imitating them. This prize 
 was gained by M. Kratzenstein, who showed that all the 
 vowels could be distinctly pronounced by blowing through 
 a reed into the lower ends of the pipes of the annexed 
 figures, as shown in Fig. 47, where the corresponding 
 vowels are marked on the different pipes. The vowel I is 
 
 Fig. 47. 
 
 pronounced by merely blowing into the pipe a 6, of the 
 pipe marked I, without the use of a reed. 
 
 About the same time that Kratzenstein was engaged in 
 these researches, M. Kempelen of Vienna, a celebrated 
 mechanician, was occupied with the same subject. In his 
 first attempt he produced the vowel sounds, by adapting a 
 reed R, Fig. 48, to the bottom of a funnel-shaped cavity 
 A B, and placing his hand in various positions within the 
 funnel. This contrivance, however, was not fitted for his 
 purpose ; but after long study, and a diligent examination of 
 the organs of speech, he contrived a hollow oval box, divided 
 into two portions attached by a hinge so as to resemble 
 jaws. This box received the sound which issued from the 
 tube connected with the reed, and by opening and closing 
 the jaws he produced the sounds A, 0, O U, and an 
 imperfect E, but no indications of an I. After two years' 
 labour he succeeded in obtaining from different jaws the 
 
KEMPELEN S TALKING ENGINE. 
 
 269 
 
 sounds of the consonants P, M, L, and by means of these 
 vowels and consonants, he could compose syllables and 
 words, such as mama, papa, aula, lama, mulo. The sounds 
 of two adjacent letters, however, run into each other, and 
 an aspiration followed some of the consonants, so that 
 instead of papa the word sounded phaa-ph-a ; these diffi- 
 culties he contrived with much labour to surmount, and he 
 found it necessary to imitate the human organs of speech 
 Fig. 48. 
 
 by having only one mouth and one glottis. The mouth 
 consisted of a funnel or bell-shaped piece of elastic gum, 
 which approximated, by its physical properties, to the 
 softness and flexibility of the human organs.* To the 
 mouth-piece was added a nose made of two tin tubes, 
 which communicated with the mouth. When both these 
 tubes were open, and the mouth-piece closed, a perfect M 
 was produced, and when one was closed and the other 
 open, an N was sounded. M. Kempelen could have 
 succeeded in obtaining the four letters D, G, K, T, but by 
 using a P instead of them, and modifying the sound in a 
 particular manner, he contrived to deceive the ear by a 
 tolerable resemblance of these letters. 
 
 * Had M. Kempelen known the modern discovery of giving 
 caoutchouc any degree of softness, by mixing it "with molasses or 
 sugar, which is always absorbing moisture from the atmosphere, he 
 might have obtained a still more perfect imitation of the human 
 organs. 
 
270 LETTERS ON NATURAL MAGIC. 
 
 There seems to be no doubt that he at last was able to 
 produce entire words and sentences, such as opera, 
 astronomy, Constantinopolis, vous etes mon ami, je vous aime 
 de tout mon cceur, venez avec moi a Paris, Leopoldus secundus, 
 Homanorum imperator semper Augustus, &c., but he never 
 fitted up a speaking figure, and probably, from being 
 dissatisfied with the general result of his labours, he 
 exhibited only to his private friends the effects of the 
 apparatus, which was fitted up in the form of a box. 
 
 This box was rectangular, and about three feet long, 
 and was placed upon a table and covered with a cloth. 
 When any particular word was mentioned by the com- 
 pany, M. Kempelen caused the machine to pronounce 
 it, by introducing his hands beneath the cloth, and appa- 
 rently giving motion to some parts of the apparatus. Mr. 
 Thomas Collinson, who had seen this machine in London, 
 mentions in a letter to Dr. Hutton, that he afterwards saw 
 it at M. Kempelen's own house in Vienna, and that he 
 then gave it the same word to be pronounced which he 
 gave it in London, viz., the word Exploitation, which, he 
 assures us, it again distinctly pronounced with the French 
 accent. 
 
 M. Kratzen stein seems to have been equally unsuccess- 
 ful, for though he assured M. De Lalande, when he saw 
 him in Paris in 1786, that he had made a machine which 
 could speak pretty well, and though he showed him some 
 of the apparatus by which it could sound the vowels, and 
 even such syllables as papa and mama, yet there is no 
 reason to believe that he had accomplished more than 
 this. 
 
 The labours of Kratzenstein and Kempelen have been 
 recently pursued with great success by our ingenious 
 countryman Mr. Willis of Cambridge. In repeating 
 Kempelen's experiment shown in Fig. 48, he used a 
 shallower cavity, such as that in Fig. 49, and found that 
 
WILLIS'S VOWEL MACHINE. 271 
 
 he could entirely dispense with 'the introduction of the 
 hand, and could obtain the whole series of vowels, by 
 sliding a flat board C D over the mouth of the cavity. 
 Mr. Willis then conceived the idea of adapting to the reed 
 cylindrical tubes, whose length could be varied by sliding 
 joints. When the tube was greatly less than the length 
 of a stopped pipe in unison with the reed, it sounded I, 
 and by increasing the length of the tube it gave E, A, 
 and U in succession. But what was very unexpected, 
 
 Fig. 49. 
 
 when the tube was so much lengthened as to be 1J times 
 the length of a stopped pipe in unison with the reed, the 
 vowels began to be again sounded in an inverted order, 
 viz., U, 0, A, E, and then again in a direct order, I, E, A 
 O, U, when the length of the tube was equal to twice that 
 of a stopped pipe, in unison with the reed. 
 
 Some important discoveries have been recently made by 
 M. Savart respecting the mechanism of the human voice,* 
 and we have no doubt that, before another century is 
 completed, a Talking and a Singing machine will be 
 numbered among the conquests of Science. 
 
 * See Edinburgh Journal of Science, No. viii. p. 200. 
 
272 LETTERS ON NATURAL MAGIC. 
 
 LETTER IX. 
 
 Singular effects in nature depending on sound Permanent character 
 of speech Influence of great elevations on the character of soimds* 
 and on the powers of speech Poiver of sound in throwing down 
 buildings Dog killed by sound Sounds greatly changed under 
 particular circumstances Great audibility of sounds during the 
 night explained Sounds deadened in media of different densities 
 Illustrated in the case of a glass of champagne, and in that of 
 new-fallen snow Remarkable echoes Reverberations of thunder 
 Subterranean noises Remarkable one at the Solfaterra Echo 
 at the Menai Suspension Bridge Temporary deafness produced in 
 diving-bells Inaudibility of particular sounds to particular ears 
 Vocal powers of the statue of Memnon Sounds in granite rocks 
 Musical mountain of El-Nakous. 
 
 ALTHOUGH among the phenomena of the material world 
 there is scarcely one which, when well considered, is not 
 an object of wonder, yet those which we have been 
 accustomed to witness from our infancy lose all their 
 interest from the frequency of their occurrence, while to 
 the natives of other countries they are unceasing objects of 
 astonishment and delight. The inhabitant of a tropical 
 climate is confounded at the sight of falling snow, and he 
 almosts discredits the evidence of his senses when he sees 
 a frozen river carrying loaded waggons on its surface. 
 The diffusion of knowledge by books, as well as by 
 frequent communication between the natives of different 
 quarters of the globe, have deprived this class of local 
 wonders of their influence, and the Indian and the 
 Scandinavian can visit each other's lands without any 
 violent excitement of surprise. Still, however, there are 
 
PERMANENT CHARACTER OF SPEECH. 273 
 
 phenomena of rare occurrence, of which no description can 
 convey the idea, and which continue to be as deeply 
 marked with the marvellous as if they had been previously 
 unknown. Among these we may rank the remarkable 
 modifications which sound undergoes in particular situa- 
 tions and under particular circumstances. 
 
 In the ordinary intercourse of life, we recognise indi- 
 viduals as much by their voice as by the features of their 
 face and the form of their body. A friend who has been 
 long absent will often stand before us as a stranger, till 
 his voice supplies us with the full power of recognition. 
 The brand imprinted by time on his outer form may 
 have effaced the youthful image which the memory had 
 cherished, but the original character of his voice and its 
 yet remembered tones will remain unimpaired. 
 
 An old friend with a new face is not more common in 
 its moral than in its physical acceptation, and though the 
 sagacity of proverbial wisdom has not supplied us with the 
 counterpart in relation to the human voice, yet the 
 influence of its immutability over the mind has been 
 recorded by the poet in some of his most powerful 
 conceptions. When Manfred was unable to recognise in 
 the hectic phantom of Astarte the endeared lineaments of 
 the being whom he loved, the mere utterance of his name 
 recalled "the voice which was his music," and invested 
 her with the desired reality : 
 
 Say on, say on 
 I live but in the Sound It is thy voice ! 
 
 BYRON. 
 
 The permanence of character thus impressed upon 
 speech exists only in those regions to whose atmosphere 
 our vocal organs are adapted. If either the speaker or the 
 hearer is placed in air differing greatly in density from 
 that to which they are accustomed, the voice of the one 
 will emit different sounds, or the same sounds will pro- 
 
274 LETTERS ON NATURAL MAGIC. 
 
 duce a different impression on the ear of the other. But 
 if both parties are placed in this new atmosphere, their 
 tones of communication will suffer the most remarkable 
 change. The two extreme positions, where such effects 
 become sufficiently striking, are in the compressed air of 
 the diving-bell, when it is immersed to a great depth in 
 the sea, or in the rarefied atmosphere which prevails on 
 the summit of the Himalaya or the Andes. 
 
 In the region of common life, and even at the stillest 
 hour of night, the ear seldom rests from its toils. When 
 the voice of man and the bustle of his labours have ceased, 
 the sounds of insect life are redoubled, the night breeze 
 awakens among the rustling leaves, and the swell of the 
 distant ocean, and the sounds of the falling cataract or of 
 the murmuring brook, fill the air with their pure and 
 solemn music. The sublimity of deep silence is not to 
 be found even in the steppes of the Volga, or in the 
 forests of the Orinoco. It can be felt only in those lofty 
 
 regions 
 
 Where the tops of the Andes 
 Shoot soaringly forth. 
 
 As the traveller rises above the limit of life and motion, 
 and enters the region of habitual solitude, the death-like 
 silence which prevails around him is rendered still more 
 striking by the diminished density of the air which he 
 breathes. The voice of his fellow-traveller ceases to be 
 heard even at a moderate distance, and sounds which 
 would stun the ear at a lower level make but a feeble 
 impression. The report of a pistol on the top of Mont 
 Blanc is no louder than that of an Indian cracker. But 
 while the thinness of the air thus subdues the loudest 
 sounds, the voice itself undergoes a singular change : the 
 muscular energy by which we speak experiences a great 
 diminution, and our powers of utterance, as well as our 
 power of hearing, are thus singularly modified. Were the 
 
INFLUENCE OF ELEVATION ON SOUNDS. 275 
 
 magician, therefore, who is desirous to impress upon his 
 victim or upon his pupil the conviction of his supernatural 
 power, to carry him, under the injunction of silence, 
 
 to breathe 
 
 The difficult air of the iced mountain's top, 
 Where the birds dare not build, nor insect's wing 
 Flit o'er the herbless granite, 
 
 he would experience little difficulty in asserting his power 
 over the elements, and still less in subsequently com- 
 municating the same influence to his companion. 
 
 But though the air at the tops of our highest mountains 
 is scarcely capable of transmitting sounds of ordinary 
 intensity, yet sounds of extraordinary power force their 
 way through its most attenuated strata. At elevations 
 where the air is three thousand times more rare than that 
 which we breathe, the explosion of meteors is heard like 
 the sound of cannon on the surface of the earth, and the 
 whole air is often violently agitated by the sound. This 
 fact alone may give us some idea of the tremendous nature 
 of the forces which such explosions create, and it is 
 fortunate for our species that they are confined to the 
 upper regions of the atmosphere. If the same explosions 
 were to take place in the dense air which rests upon the 
 earth, our habitations and our lives would be exposed to 
 the most imminent peril. 
 
 Buildings have often been thrown down by violent 
 concussions of the air, occasioned either by the sound of 
 great guns or by loud thunder, and the most serious 
 effects upon human and animal life have been produced 
 by the same cause. Most persons have experienced the 
 stunning pain produced in the ear when placed near a 
 cannon that is discharged. Deafness has frequently been 
 the result of such sudden concussions, and if we may 
 reason from analogy, death itself must often have been the 
 consequence. When peace was proclaimed in London in 
 
276 LETTERS ON NATURAL MAGIC. 
 
 1697, two troops of horse were dismounted and drawn tip 
 in line in order to fire their volleys. Opposite the centre 
 of the line was the door of a butcher's shop, where there 
 was a large mastiff dog of great courage. This dog was 
 sleeping by the fire, but when the first volley was fired, it 
 immediately started up, ran into another room, and hid 
 itself under a bed. On the firing of the second volley, the 
 dog rose, run several times about the room, trembling 
 violently and apparently in great agony. When the third 
 volley was fired, the dog ran about once or twice with 
 great violence, and instantly fell down dead, throwing up 
 blood from his mouth and nose. 
 
 Sounds of known character and intensity are often 
 singularly changed even at the surface of the earth, accord- 
 ing to the state of the ground and the conditions of the 
 clouds. On the extended heath, where there are no solid 
 objects capable of reflecting or modifying sound, the 
 sportsman must frequently have noticed the unaccountable 
 variety of sounds which are produced by the report of 
 his fowling-piece. Sometimes they are flat and prolonged, 
 at other times short and sharp, and sometimes the noise 
 is so strange that it is referred to some mistake in the 
 loading of the gun. These variations, however, arise 
 entirely from the state of the air, and from the nature and 
 proximity of the superjacent clouds. In pure air of 
 uniform density the sound is sharp and soon over, as the 
 undulations of the air advance without any interrupting 
 obstacles. In a foggy atmosphere, or where the vapours 
 produced by heat are seen dancing as it were in the air, 
 the sound is dull and prolonged ; and when these clouds 
 are imm diately overhead, a succession of echoes from 
 them produces a continued or a reverberating sound. 
 When the French astronomers were determining the 
 velocity of sound by firing great guns, they observed that 
 the report was always single and sharp under a perfectly 
 
SOUNDS DURING THE NIGHT. 277 
 
 clear sky, but indistinct, and attended by a long-continued 
 roll like thunder, when a cloud covered a considerable 
 part of the horizon. It is no doubt owing to the same 
 cause, namely, the reflection from the clouds, that the 
 thunder rolls through the heavens, as if it were produced 
 by a succession of electric explosions. 
 
 The great audibility of sounds during the night is a 
 phenomenon of considerable interest, and one which had 
 been observed even by the ancients. In crowded cities or 
 in their vicinity, the effect was generally ascribed to the 
 rest of animated beings, while in localities where such 
 an explanation was inapplicable, it was supposed to arise 
 from a favourable direction of the prevailing wind. Baron 
 Humboldt was particularly struck with this phenomenon 
 when he first heard the rushing of the great cataracts of 
 the Orinoco in the plain which surrounds the mission of 
 the Apures. These sounds he regarded as three times 
 louder during the night than during the day. Some 
 authors ascribed this fact to the cessation of the humming 
 of insects, the singing of birds, and the action of the 
 wind on the leaves of the trees, but M. Humboldt justly 
 maintains that this cannot be the cause of it on the 
 Orinoco, where the buzz of insects is much louder in the 
 night than in the day, and where the breeze never rises 
 till after sunset. Hence he was led to ascribe the pheno- 
 menon to the perfect transparency and uniform density 
 of the air, which can exist only at night after the heat of 
 the ground has been uniformly diffused through the 
 atmosphere. When the rays of the sun have been beating 
 on the ground during the day, currents of hot air of 
 different temperatures, and consequently of different 
 densities, are constantly ascending from the ground and 
 mixing with the cold air above. The air thus ceases to 
 be a homogeneous medium, and every person must have 
 observed the effects of it upon objects seen through it 
 
278 LETTERS ON NATURAL MAGIC. 
 
 which are very indistinctly visible, and have a tremulous 
 motion, as if they were " dancing in the air." The very 
 same effect is perceived when we look at objects through 
 spirits and water that are not perfectly mixed, or when 
 we view distant objects over a red-hot poker or over a 
 flame. In all these cases the light suffers refraction in 
 passing from a medium of one density into a medium of 
 a different density, and the refracted rays are constantly 
 changing their direction as the different currents rise in 
 succession. Analogous effects are produced when sound 
 passes through a mixed medium, whether it consists of 
 two different mediums, or of one medium where portions 
 of it have different densities. As sound moves with 
 different velocities through media of different densities, 
 the wave which produces the sound will be partly reflected 
 in passing from one medium to the other, and the direc- 
 tion of the transmitted wave changed; and hence in 
 passing through such media different portions of the wave 
 will reach the ear at different times, and thus destroy the 
 sharpness and distinctness of the sound. This may be 
 proved by many striking facts. If we put a bell in a 
 receiver containing a mixture of hydrogen gas and atmo- 
 spheric air, the sound of the bell can scarcely be heard. 
 During a shower of rain or of snow, noises are greatly 
 deadened, and when sound is transmitted along an iron 
 wire or an iron pipe of sufficient length, we actually hear 
 two sounds, one transmitted more rapidly through the 
 solid, and the other more slowly through the air. The 
 same property is well illustrated by an elegant and easily- 
 repeated experiment of Chladni's. When sparkling 
 champagne is poured into a tall glass till it is half full, 
 the glass loses its power of ringing by a stroke upon its 
 edge, and emits only a disagreeable and puffy sound. 
 This effect will continue while the wine is filled with 
 bubbles of air, or as long as the effervescence lasts ; but 
 
REMARKABLE ECHOES. 279 
 
 when the effervescence begins to subside, the sound 
 becomes clearer and clearer, and the glass rings as usual 
 when the air-bubbles have vanished. If we reproduce 
 the effervescence by stirring the champagne with a 
 piece of bread the glass will again cease to ring. The 
 same experiment will succeed with other effervescing 
 fluids. 
 
 The difference in the audibility of sounds that pass 
 over homogeneous and over mixed media is sometimes 
 so remarkable as to astonish those who witness it. The 
 following fact is given on the evidence of an officer 
 who observed it. When the British and the American 
 forces were encamped on each side of a river, the outposts 
 were so near that the forms of individuals could be easily 
 distinguished. An American drummer made his appear- 
 ance and began to beat his drum, but though the motion 
 of his arms was distinctly seen, not a single sound 
 reached the ear of the observer. A coating of snow that 
 had newly fallen upon the ground, and the thickness of 
 the atmosphere, had conspired to obstruct the sound. An 
 effect the very reverse of this is produced by a coating 
 of glazed or hardened snow, or by an extended surface of 
 ice or water. Lieutenant Foster was able to carry on a 
 conversation with a sailor across Port Bowen harbour, a 
 distance of no less than a mile and a quarter, and the 
 sound of great guns has been heard at distances varying 
 from 120 to 200 miles. Over hard and dry ground of 
 an uniform character, or where a thin soil rests upon a 
 continuous stratum of rock, the sound is heard at a great 
 distance, and hence it is the practice among many eastern 
 tribes to ascertain the approach of an enemy by applying 
 the ear to the ground. 
 
 Many remarkable phenomena in the natural world are 
 produced by the reflection and concentration of sound. 
 Every person is familiar with the ordinary Echo which 
 
280 LETTERS ON NATURAL MAGIC. 
 
 arises from the reflection of sound from an even surface, 
 such as the face of a wall, of a house, of a rock, of a hill, 
 or of a cloud. As sound moves at the rate of 1090 feet 
 in a second, and as the sound which returns to the person 
 who emits it has travelled over a space equal to twice his 
 distance from the reflecting surface, the distance in feet 
 of the body which occasions the echo may be readily found 
 by multiplying 545 by the number of seconds which 
 elapse between the emission of the sound and its return 
 in the form of an echo. This kind of echo, where the 
 same person is the speaker and the hearer, never takes 
 place unless when the observer is immediately in front of 
 the reflecting surface, or when a line drawn from his 
 mouth to the flat surface is nearly perpendicular to it, 
 because in this case alone the wave of sound is reflected 
 in the very same direction from the wall in which it 
 reaches it. If the speaker places himself on one side of 
 this line, then the echo will be heard most distinctly by 
 another person as far on the other side of it, because the 
 waves of sound are reflected like light, so that the angle 
 of incidence or the inclination at which the sound falls 
 upon the reflected surface is equal to the angle of reflec- 
 tion, or the inclination at which the sound is returned 
 from the wall. If two persons, therefore, are placed 
 before the reflecting wall, the one will hear the echo of 
 the sound emitted by the other, and obstacles may inter- 
 vene between these two persons so that neither of them 
 hears the direct sound emitted by the other ; in the same 
 manner as the same persons similarly placed before a 
 looking-glass would see each other distinctly by reflection, 
 though objects might obstruct their direct view of each 
 other. 
 
 Hitherto we have supposed that there is only one 
 reflecting surface, in which case there will be only one 
 echo ; but if there are several reflecting surfaces, as is 
 
REMARKABLE ECHOES. 281 
 
 the case in an amphitheatre of mountains, or during a 
 thunder-storm, where there are several strata or masses 
 of clouds ; or if there are two parallel or inclined surfaces 
 between which the sound can be repeatedly reflected, or 
 if the surface is curved so that the sound reflected from 
 one part falls upon another part, like the sides of a 
 polygon inscribed in a circle in all these cases there 
 will be numerous echoes, which produce a very singular 
 effect. Nothing can be more grand and sublime than the 
 primary and secondary echoes of a piece of ordnance 
 discharged in an amphitheatre of precipitous mountains. 
 The direct or primary echoes from each reflecting surface 
 reach the ear in succession, according to their different 
 distances, and these are either blended with or succeeded 
 by the secondary echoes which terminate in a prolonged 
 growl ending in absolute silence. Of the same character 
 are the reverberated claps of a thunder-bolt reflected from 
 the surrounding clouds, and dying away in the distance. 
 The echo which is produced by parallel walls is finely 
 illustrated at the Marquis of Simonetta's villa near Milan, 
 which has been described by Addison and Keysler, and 
 which we believe is that described by Mr. Southwell in 
 the Philosophical Transactions for 1746. Perpendicular 
 to the main body of this villa there extend two parallel 
 wings about fifty-eight paces distant from each other, and 
 the surfaces of which are unbroken either with doors or 
 windows. The sound of the human voice, or rather a 
 word quickly pronounced, is repeated above forty times, 
 and the report of a pistol from fifty-six to sixty times. 
 The repetitions, however, follow in such rapid succession 
 that it is difficult to reckon them, unless early in the 
 morning before the equal temperature of the atmosphere 
 is disturbed, or in a calm still evening. The echoes 
 appear to be best heard from a window in the main 
 building between the two projecting walls, from which the 
 
 u 
 
282 LETTEKS ON NATURAL MAGIC, 
 
 pistol also is fired. Dr. Plot mentions an echo in Wood- 
 stock Park which repeats seventeen syllables by day 
 and twenty by night. An echo on the north side of 
 Shipley Church in Sussex repeats twenty-one syllables. 
 Sir John Herschel mentions an echo in the Manfroni 
 palace at Venice, where a person standing in the centre 
 of a square room about twenty -five feet high, with a 
 concave roof, hears the stamp of his foot repeated a great 
 many times, but as his position deviates from the centre, 
 the echoes become feebler, and at a short distance entirely 
 cease. The same phenomenon, he remarks, occurs in the 
 large room of the library of the museum at Naples. 
 M. Genefay has described as existing near Eouen a 
 curious oblique echo which is not heard by the person 
 who emits the sound. A person who sings hears only 
 his own voice, while those who listen hear only the echo, 
 which sometimes seems to approach, and at other times 
 to recede from the ear ; one person hears a single sound, 
 another several sounds, and one hears it on the right and 
 another on the left, the effect always changing as the 
 hearer changes his position. Dr. Birch has described 
 an extraordinary echo at Eoseneath in Argyleshire, which 
 certainly does not now exist. When eight or ten notes 
 were played upon a trumpet they were correctly repeated, 
 but on a key a third lower. After a short pause another 
 repetition of the notes was heard in a still lower tone, 
 and after another short interval they were repeated in a 
 still lower tone. 
 
 In the same manner as light is always lost by reflection, 
 so the waves of sound are enfeebled by reflection from 
 ordinary surfaces, and the echo is in such cases fainter 
 than the original sound. If the reflecting surface, how- 
 ever, is circular, sound may be condensed and rendered 
 stronger in the same manner as light. I have seen a fine 
 example of this in the circular turn of a garden wall 
 
WHISPERING GALLERY. 283 
 
 nearly a mile distant from a weir across a river. When 
 the air is pure and homogeneous, the rushing sound 
 of the water is reflected from the hollow surface 
 of the wall, and concentrated in a focus, the place of 
 which the ear can easily discover from the intensity of 
 the sound being there a maximum. A person not ac- 
 quainted with the locality conceives that the rushing 
 noise is on the other side of the wall. 
 
 In Whispering Galleries, or places where the lowest 
 whispers are carried to distances at which the direct 
 sound is inaudible, the sound may be conveyed in two 
 ways, either by repeated reflections from a curved surface 
 in the direction of the sides of a polygon inscribed in a 
 circle, or where the whisperer is in the focus of one 
 reflecting surface, and the hearer in the focus of another 
 reflecting surface, which is placed so as to receive the 
 reflected sounds. The first of these ways is exemplified in 
 the whispering gallery of St. Paul's, and in the octagonal 
 gallery of Gloucester Cathedral, which conveys a whisper 
 seventy- five feet across the nave, and the second in the 
 baptistery of a church in Pisa, where the architect Giovanni 
 Pisano is said to have constructed the cupola on purpose. 
 The cupola has an elliptical form, and when one person 
 whispers in one focus, it is distinctly heard by the person 
 placed in the other focus, but not by those who are placed 
 between them. The sound first reflected passes across the 
 cupola, and enters the ears of the intermediate persons, but 
 it is too feeble to be heard till it has been condensed by a 
 second reflection to the other focus of ellipse. A naval 
 officer, who travelled through Sicily in the year 1824, 
 gives an account of a powerful whispering place in the 
 cathedral of Girgenti, where the slightest whisper is 
 carried with perfect distinctness through a distance of 
 250 feet, from the great western door to the cornice 
 behind the high altar. By an unfortunate coincidence 
 
284 LETTERS ON NATURAL MAGIC. 
 
 the focus of one of the reflecting surfaces was chosen for 
 the place of the confessional, and when this was acci- 
 dentally discovered, the lovers of secrets resorted to the 
 other focus, and thus became acquainted with confessions 
 of the gravest import. This divulgence of scandal con- 
 tinued for a considerable time, till the eager curiosity of 
 one of the dilettanti was punished, by hearing his wife's 
 avowal of her own infidelity. This circumstance gave 
 publicity to the whispering peculiarity of the cathedral, 
 and the confessional was removed to a place of greater 
 secrecy. 
 
 An echo of a very peculiar character has been described 
 by Sir John Herschel in his Treatise on Sound, as pro- 
 duced by the suspension bridge across the Menai Strait in 
 Wales. " The sound of a blow with a hammer," says he, 
 " on one of the main piers is returned in succession from 
 each of the cross beams which support the road-way, and 
 from the opposite pier at a distance of 576 feet ; and in 
 addition to this, the sound is many times repeated between 
 the water and the road-way. The effect is a series of 
 sounds which may be thus written : the first return is 
 
 Fig. 50. 
 
 f rrrrrrrr 
 
 sharp and strong from the road-way overhead ; the rattling 
 which succeeds dies away rapidly, but the single reper- 
 cussion from the opposite pier is very strong, and is suc- 
 ceeded by a faint palpitation repeating the sound at the 
 rate of twenty-eight times in five seconds, and which, 
 therefore, corresponds to a distance of 184 feet, or very 
 nearly the double interval from the road-way to the 
 water. Thus it appears that in the repercussion between 
 
SUBTERRANEAN ECHO, 285 
 
 the water and road-way, that from the latter only affects 
 the ear, the line drawn from the auditor to the water 
 being too oblique for the sound to diverge sufficiently in 
 that direction. Another peculiarity deserves especial 
 notice, namely, that the echo from the opposite pier is 
 best heard when the auditor stands precisely opposite to 
 the middle of the breadth of the pier, and strikes just on 
 that point. As it deviates to one or the other side, the 
 return is proportionally fainter, and is scarcely heard by 
 him when his station is a little beyond the extreme edge 
 of the pier, though another person, stationed (on the 
 same side of the water) at an equal distance from the 
 central point, so as to have the pier between them, hears 
 it well." 
 
 A remarkable subterranean echo is often heard when 
 the hoofs of a horse or the wheels of a carriage pass over 
 particular spots of ground. This sound is frequently 
 very similar to that which is produced in passing over an 
 arch or vault, and is commonly attributed to the existence 
 of natural or artificial caves beneath. As such caves have 
 often been constructed in times of war as places of secu- 
 rity for persons and property, many unavailing attempts 
 have been made to discover hidden treasures where their 
 locality seemed to be indicated by subterraneous sounds. 
 But though these sounds are sometimes produced by ex- 
 cavations in the ground, yet they generally arise from the. 
 nature of the materials of which the ground is composed, 
 and from their manner of combination. If the hollow of 
 a road has been filled up with broken rock, or with large 
 water-worn stones, having hollows either left entirely 
 empty, or filled up with materials of different density, 
 then the sound will be reflected in passing from the loose 
 to the dense materials, and there will arise a great number 
 of echoes reaching the ear in rapid succession, and forming 
 by their union a hollow rumbling sound. This principle 
 
286 LETTERS ON NATURAL MAGIC. 
 
 lias been very successfully applied by Sir John Herscliel 
 to explain the subterranean sounds with which every 
 traveller is familiar who has visited the Solfaterra near 
 Naples. When the ground at a particular place is struck 
 violently by throwing a large stone against it, a peculiar 
 hollow sound is distinctly heard. This sound has been 
 ascribed by some geologists to the existence of a great 
 vault communicating with the ancient seat of the volcano, 
 by other writers to a reverberation from the surrounding 
 hills with which it is nearly concentric, and by others to 
 the porosity of the ground. Dr. Daubeny, who says that 
 the hollow sound is heard when any part of the Solfaterra 
 is struck, accounts for it by supposing that the hill is not 
 made up of one entire rock, but of a number of detached 
 blocks, which, hanging as it were by each other, form a 
 sort of vault over the abyss within which the volcanic 
 operations are going on.* Mr. Forbes, who has given 
 the latest and most interesting description of this singular 
 volcano,f agrees in opinion with Dr. Daubeny, while 
 Mr. Scrope J and Sir John Herschel concur in opinion 
 that no such cavities exist. " It seems most probable," 
 says the latter, " that the hollow reverberation is nothing 
 more than an assemblage of partial echoes arising from 
 the reflection of successive portions of the original sound 
 in its progress through the soil at the innumerable half- 
 coherent surfaces composing it : were the whole soil a 
 mass of sand, these reflections would be so strong and 
 frequent as to destroy the whole impulse, in too short an 
 interval to allow of a distinguishable after-sound. It is a 
 case analogous to that of a strong light, thrown into a 
 milky medium or smoky atmosphere ; the whole medium 
 
 * Description of Volcanoes, p. 170. 
 
 t Edinburgh Journal of Science, N. Series, No. i. p. 124. 
 J Considerations on Volcanoes, and Edinburgh Journal of Science, 
 No, xx. p. 261, and No. xiv. p. 265. 
 
MOMENTARY DEAFNESS. 287 
 
 appears to shine with a nebulous undefined light. This 
 is to the eye what such a hollow sound is to the ear.''* 
 
 It has been recently shown by M. Savart, that the 
 human ear is so extremely sensible as to be capable of 
 appreciating sounds which arise from about twenty-four 
 thousand vibrations in a second, and consequently, that it 
 can hear a sound which lasts only the twenty-four thou- 
 sandth part of a second. Vibrations of such frequency 
 afford only a shrill squeak or chirp ; and Dr. Wollaston 
 has shown that there are many individuals with their 
 sense of hearing entire, who are altogether insensible to 
 such acute sounds, though others are painfully affected by 
 them. Nothing, as Sir John Herschel remarks, can be 
 more surprising than to see two persons, neither of them 
 deaf, the one complaining of the penetrating shrillness of 
 a sound, while the other maintains there is no sound at 
 all. Dr. Wollaston has also shown that this is true also 
 of very grave sounds, so that the hearing or not hearing 
 of musical notes at both extremities of the scale seems to 
 depend wholly on the pitch or frequency of vibration con- 
 stituting the note, and not upon the intensity or loudness 
 of the noise. This affection of the ear sometimes appears 
 in cases of common deafness, where a shrill tone of voice, 
 such as that of women and children, is often better heard 
 than the loud and deeper tone of men. 
 
 Dr. Wollaston remarked, that when the mouth and 
 nose are shut, the tympanum or drum of the ear may be 
 so exhausted by a forcible attempt to take breath by the 
 expansion of the chest, the pressure of the external air 
 upon the membrane gives it such a tension, that the ear 
 becomes insensible to grave tones, without losing in any 
 degree the perception of sharper sounds. Dr. Wollaston 
 found, that after he had got into the habit of making the 
 experiment, so as to be able to produce a great degree of 
 
 * Art. SOUND, Encyd. Metrop. 110. 
 
288 LETTERS ON NATURAL MAGIC. 
 
 exhaustion, his ears were insensible to all sounds below 
 F, marked by the base clef. "If I strike the table before 
 me," says he, "with the end of my finger, the whole 
 board sounds with a deep dull note. If I strike it with 
 my nail, there is also at the same time a sharp sound pro- 
 duced by quicker vibrations of parts around the point of 
 contact. When the ear is exhausted it hears only the 
 latter sound, without perceiving in any degree the deeper 
 note of the whole table. In the same manner, in listening 
 to the sound of a carriage, the deeper rumbling noise of 
 the body is no longer heard by an exhausted ear ; but the 
 rattle of a chain or loose screw remains at least as audible 
 as before exhaustion." Dr. Wollaston supposes that this 
 excessive tension of the drum of the ear, when produced 
 by the compressed air in the diving-bell, will also produce 
 a corresponding deafness to low tones. This curious experi- 
 ment has been since made by Dr. Colladon, when descend- 
 ing in the diving-bell at Howth in 1820. "We de- 
 scended," says he, " so slowly that we did not notice the 
 motion of the bell ; but as soon as the bell was immersed 
 in water, we felt about the ears and the forehead a sense 
 of pressure, which continued increasing during some 
 minutes. I did not, however, experience any pain in the 
 ears ; but my companion suffered so much that we were 
 obliged to stop our descent for a short time. To remedy 
 that inconvenience, the workmen instructed us, after 
 having closed our nostrils and mouth, to endeavour to 
 swallow, and to restrain our respiration for some moments, 
 in order that, by this exertion, the internal air might act 
 on the Eustachian tube. My companion, however, having 
 tried it, found himself very little relieved by this remedy. 
 After some minutes, we resumed our descent. My friend 
 suffered considerably ; he was pale ; his lips were totally 
 discoloured; his appearance was that of a man on the 
 point of fainting; he was in involuntary low spirits, 
 
INAUDIBILITY OF CERTAIN SOUNDS. 289 
 
 owing, perhaps, to the violence of the pain, added to that 
 kind of apprehension which our situation unavoidably 
 inspired. This appeared to me the more remarkable, as 
 my case was totally the reverse. I was in a state of ex- 
 citement resembling the effect of some spirituous liquor. 
 I suffered no pain ; I experienced only a strong pressure 
 round my head, as if an iron circle had been bound about 
 it. I spoke with the workmen and had some difficulty in 
 hearing them. This difficulty of hearing rose to such a 
 height, that during three or four minutes I could not hear 
 them speak. I could not, indeed, hear myself speak, 
 though I spoke as loudly as possible ; nor did even the 
 great noise caused by the violence of the current against 
 the sides of the bell reach my ears." 
 
 The effect thus described by Dr. Colladon is different 
 from that anticipated by Dr. Wollaston. He was not 
 merely deaf to low tones but to all sounds whatever ; and 
 I have found by repeated experiment, that my own ears 
 become perfectly insensible even to the shrill tones of the 
 female voice, and of the voice of a child, when the drum 
 of the ear is thrown into a state of tension by yawning. 
 
 With regard to sounds of high pitch at the other 
 extremity of the scale, Dr. Wollaston has met with 
 persons, whose hearing was in other respects perfect, who 
 never heard the chirping of the Gryllus campestris, which 
 commonly occurs in hedges during a summer's evening, 
 or that of the house-cricket, or the squeak of the bat, or 
 the chirping of the common house-sparrow. The note of 
 the bat is a full octave higher than that of the sparrow ; 
 and Dr. Wollaston believes that the note of some insects 
 may reach one octave more, as there are sounds decidedly 
 higher than that of a small pipe, one-fourth of an inch in 
 length, which he conceives cannot be far from six octaves 
 above the middle E of the pianoforte. " The suddenness 
 of the transition," says Dr. Wollaston, "from perfect 
 
21)0 LETTERS ON NATURAL MAGIC. 
 
 hearing to total want of perception occasions a degree of 
 surprise, which renders an experiment on this subject with 
 a series of small pipes among several persons rather 
 amusing. It is curious to observe the change of feeling 
 manifested by various individuals of the party, in succes- 
 sion, as the sounds approach and pass the limits of their 
 hearing. Those who enjoy a temporary triumph are often 
 compelled in their turn to acknowledge to how short a 
 distance their little superiority extends." In concluding 
 his interesting paper on this subject, Dr. Wollaston con- 
 jectures that animals, like the grylli (whose powers of 
 hearing appear to commence nearly where ours terminate), 
 may have the power of hearing still sharper sounds which 
 at present we do not know to exist, and that there may be 
 other insects having nothing in common with us, but who 
 are endowed with a power of exciting, and a sense of per- 
 ceiving vibrations which make no impression upon our 
 organs, while their organs are equally insensible to the 
 slower vibrations to which we are accustomed. 
 
 With the view of studying the class of sounds inaudible 
 to certain ears, we would recommend to the young 
 naturalist to examine the sounds emitted by the insect 
 tribe, both in relation to their effect upon the human ear, 
 and to the mechanism by which they are produced. The 
 CicadaB or locusts in North America appear, from the 
 observations of Dr. Hildreth,* to be furnished with a 
 bagpipe on which they play a variety of notes. " When 
 any one passes," says he, " they make a great noise and 
 screaming with their air-bladder or bagpipes. These bags 
 are placed under, and rather behind, the wings in the 
 axilla, something in the manner of using the bagpipes 
 with the bags under the arms, I could compare them to 
 nothing else ; and, indeed, I suspect the first inventor of 
 the instrument borrowed his ideas from some insect of 
 
 * Edinburgh Journal of Science, No. xvii. p. 158. 
 
VOCAL STATUE OF MEMNON. 291 
 
 this kind. They play a variety of notes and sounds, one 
 of which nearly imitates the scream of the tree-toad." 
 
 Among the acoustic wonders of the natural world 
 may be ranked the vocal powers of the statue of Memnon, 
 the son of Aurora, which modern discoveries have with- 
 drawn from among the fables of ancient Egypt. The 
 history of this remarkable statue is involved in much 
 obscurity. Although Strabo affirms that it was over- 
 turned by an earthquake, yet as Egypt exhibits no traces 
 of such a convulsion, it has been generally believed that 
 the statue was mutilated by Cambyses. Ph. Casselius, 
 in his dissertation on vocal or speaking stones, quotes 
 the remark of the scholiast in Juvenal, "that, when 
 mutilated by Cambyses, the statue which saluted both the 
 sun and the king, afterwards saluted only the sun." 
 Philostratus, in his life of Apollo, informs us, that the 
 statue looked to the east, and that it spoke as soon as the 
 rays of the rising sun fell upon its mouth. Pausanias, 
 who saw the statue in its dismantled state, says that it is 
 a statue of the sun, that the Egyptians call it Phamenophis, 
 and not Memnon, and that it emits sounds every morning at 
 sunrise, which can be compared only to that of the breaking of 
 the string of a lyre. Strabo speaks only of a single sound 
 which he heard ; but Juvenal, who had probably heard it 
 often during his stay in Egypt, describes it as if it 
 emitted several sounds : 
 
 Dimidio magicee resonant ubi Memnone chordae. 
 Where broken Memnon sounds his magic strings. 
 
 The simple sounds which issued from the statue were in 
 the progess of time magnified into intelligible words, and 
 even into an oracle of seven verses, and this prodigy has 
 been recorded in a Greek inscription on the left leg of 
 the statue. But though this new faculty of the colossus 
 was evidently the contrivance of the Egyptian priests, yet 
 
292 LETTERS ON NATURAL MAGIC. 
 
 we are not entitled from this to call in question the 
 simple and perfectly credible fact that it emitted sounds. 
 This property, indeed, it seems to possess at the present 
 day ; for we learn,* that an English traveller, Sir A. 
 Smith, accompanied with a numerous escort, examined 
 the statue, and that at six o'clock in the morning he 
 heard very distinctly the sounds which had been so cele- 
 brated in antiquity. He asserts that this sound does not 
 proceed from the statue but from the pedestal ; and he 
 expresses his belief that it arises from the impulse of the 
 air upon the stones of the pedestal, which are arranged so 
 as to produce this surprising effect. This singular 
 description is to a certain extent confirmed by the descrip- 
 tion of Strabo, who says that he was quite certain that he 
 heard a sound which proceeded either from the base, or 
 from the colossus, or from some one of the assistants. 
 As there were no Egyptian priests in the escort of Sir 
 A. Smith, we may now safely reject this last, and, for 
 many centuries, the most probable hypothesis. 
 
 The explanation suggested by Sir A. Smith, had been 
 previously given in a more specific form by M. Dussaulx, 
 the translator of Juvenal. " The statue," says he, " being 
 hollow, the heat of the sun heated the air which it con- 
 tained, and this air, issuing at some crevice, produced the 
 sounds of which the priests gave their own interpretation." 
 
 Rejecting this explanation, M. Langles, in his dis- 
 sertation on the vocal statue of Memnon, and M. Salverte, 
 in his work on the occult sciences, have ascribed the 
 sounds entirely to Egyptian priestcraft, and have even 
 gone so far as to describe the mechanism by which the 
 statue not only emitted sounds, but articulated distinctly 
 the intonations appropriate to the seven Egyptian vowels, 
 and consecrated to the seven planets. M. Langles con- 
 ceives that the sounds may be produced by a series of 
 
 * Revue Encydope'dique, 1821, Tom. ix. p. 592. 
 
VOCAL STATUE OF MEMNON. 293 
 
 hammers, which strike either the granite itself, or sonorous 
 stones like those which have been long used in China 
 for musical instruments. M. Salverte improves this imper- 
 fect apparatus, by supposing that there might be adapted 
 to these hammers a clepsydra or water-clock, or any 
 other instrument fitted to measure time, and so constructed 
 as to put the hammers in motion at sunrise. Not satisfied 
 with this supposition, he conjectures that the spring of 
 all this mechanism was to be found in the art of con- 
 centrating the rays of the sun, which was well known to 
 the ancients. Between the lips of the statue, or in some 
 less remarkable part of it concealed from view by its 
 height, he conceives an aperture to be perforated, con- 
 taining a lens or a mirror capable of condensing the 
 rays of the rising sun upon one or more metallic levers 
 which by their expansion put in motion the seven 
 hammers in succession. Hence he explains why the 
 sounds were emitted only at sunrise, and when the solar 
 rays fell upon the mouth of the statue, and why they 
 were never again heard till the sun returned to the eastern 
 horizon. As a piece of mechanism, this contrivance is 
 defective in not providing for the change in the sun's 
 amplitude, which is very considerable even in Egypt, for 
 as the statue and the lens are both fixed, and as the 
 sounds were heard at all seasons of the year, the same 
 lens which threw the midsummer rays of the sun upon 
 the hammers could not possibly throw upon them 
 his rays in winter. But even if the machinery were 
 perfect, it is obvious that it could not have survived 
 the mutilation of the statue, and could not, short of a 
 miracle, have performed its part in the time of Sir A. 
 Smith. 
 
 If we abandon the idea of the whole being a trick of the 
 priesthood, which has been generally done, and which the 
 recent observations of Sir A. Smith authorizes us to do. 
 
294 r LETTERS ON NATURAL MAGIC. 
 
 we must seek some natural cause for the phenomena 
 similar to that suggested by Dussaulx. It is curious to 
 observe how the study of nature gradually dispels the 
 consecrated delusions of ages, and reduces to the level of 
 ordinary facts what time had invested with all the 
 characters of the supernatural. And in the present case 
 it is no less remarkable that the problem of the statue of 
 Memnon should have been first solved by means of an 
 observation made by a solitary traveller wandering on the 
 banks of the Orinoco. " The granitic rock," says Baron 
 Humboldt, " on which we lay is one of those where 
 travellers on the Orinoco have heard from time to time, 
 towards sunrise, subterraneous sounds resembling those 
 of the organ. The missionaries call these stones loxas de 
 musica. ' It is witchcraft,' said our young Indian pilot. 
 We never ourselves heard these mysterious sounds either 
 at Carichana Vieja or in the upper Orinoco ; but from 
 information given us by witnesses worthy of belief, the 
 existence of a phenomenon that seems to depend on a 
 certain state of the atmosphere cannot be denied. The 
 shelves of rock are full of very narrow and deep crevices. 
 They are heated during the day to about 50. I often 
 found their temperature at the surface during the night 
 at 39, the surrounding atmosphere being at 28. It 
 may easily be conceived that the difference of temperature 
 between the subterraneous and the external air attains 
 its maximum about sunrise, or at that moment which is at 
 the same time farther from the period of the maximum 
 of the heat of the preceding day. May not these sounds 
 of an organ, then, which are heard when a person sleeps 
 upon the rock, his ear in contact with the stone, be the 
 effect of a current of air that issues out through the 
 crevices ? Does not the impulse of the air against the 
 elastic spangles of mica that intercept the crevices con- 
 tribute to modify the sounds ? May we not admit that 
 
SOUNDS IN GRANITE ROCKS. 295 
 
 the ancient inhabitants of Egypt, in passing incessantly 
 up and down the Nile, had made the same observation 
 on some rock of the Thebaid, and that the music of the 
 rocks there led to the jugglery of the priests in the statue 
 of Memnon ?" 
 
 This curious case of the production of sounds in granite 
 rocks at sunrise might have been regarded as a trans- 
 atlantic wonder which was not applicable to Egypt ; but 
 by a singular coincidence of observation, MM. Jomard, 
 Jollois, and Devilliers, who were travelling in Egypt 
 nearly about the same time that M. Humboldt was 
 traversing the wilds of South America, heard, at sunrise, 
 in a monument of granite, situated near the centre of the 
 spot on which the palace of Carnac stands, a noise resem- 
 bling that of a breaking string, the very expression by 
 which Pausanias characterizes the sound in the Mem- 
 nonian granite. The travellers regarded these sounds as 
 arising from the transmission of rarefied air through the 
 crevices of a sonorous stone, and they were of the same 
 opinion with Humboldt, that these sounds might have 
 suggested to the Egyptian priests the juggleries of the Mem- 
 nonium. Is it not strange that the Prussian and the French 
 travellers should not have gone a step farther, and solved 
 the problem of two thousand years, by maintaining that 
 the sound of the statue of Memnon was itself a natural 
 phenomenon, or a granite sound elicited at sunrise by the 
 very same causes which operated on the Orinoco and in 
 the Temple of Carnac, in place of regarding it as a trick 
 in imitation of natural sounds? If, as Humboldt sup- 
 poses, the ancient inhabitants of Egypt had, in passing 
 incessantly up and down the Nile, become familiar with 
 the music of the granite rocks of the Thebaid, how could 
 the imitation of such natural and familiar sounds be 
 regarded by the priests as a means of deceiving the 
 people ? There could be nothing marvellous in a colossal 
 
296 LETTERS ON NATURAL MAGIC. 
 
 statue of granite giving out the very same sounds that 
 were given out at the same time of the day by a granite 
 rock ; and in place of reckoning it a supernatural fact, 
 they could regard it in no other light than as the dupli- 
 cate of a well-known natural phenomenon. It is a mere 
 conjecture, however, that such sounds were common in the 
 Thebaid, and it is therefore probable that a granite rock, 
 possessing the property of emitting sounds at sunrise, had 
 been discovered by the priests, who were at the same time 
 the philosophers of Egypt, and that the block had been 
 employed in the formation of the Memnonian statue for the 
 purpose of impressing upon it a supernatural character, 
 and enabling them to maintain their influence over a 
 credulous people. 
 
 The inquiries of recent travellers have enabled us to 
 corroborate these views, and to add another remarkable 
 example of the influence of subterraneous sounds over 
 superstitious minds. About three leagues to the north 
 of Tor, in Arabia Petraea, is a mountain, within the bosom 
 of which the most singular sounds have been heard. 
 The Arabs of the Desert ascribe these sounds to a convent 
 of monks preserved miraculously under ground, and the 
 sound is supposed to be that of the Nakous, a long narrow 
 metallic ruler, suspended horizontally, which the priest 
 strikes with a hammer for the purpose of assembling the 
 monks to prayer. A Greek was said to have seen the 
 mountain open, and to have descended into the subter- 
 ranean convent, where he found fine gardens and delicious 
 water ; and, in order to give proof of his descent, he pro- 
 duced some fragments of consecrated bread, which he 
 pretended to have brought from the subterranean convent. 
 The inhabitants of Tor likewise declare that the camels 
 are not only frightened but rendered furious when they 
 hear these subterraneous sounds. 
 
 M. Seetzen, the first European traveller who visited 
 
MUSICAL MOUNTAIN OF EL-NAKOUS. 297 
 
 this extraordinary mountain, set out from Woodyel Nackel 
 on the 17th of June at five o'clock in the morning. He 
 was accompanied by a Greek Christian and some Bedouin 
 Arabs, and after a quarter of an hour's walk they reached 
 the foot of a majestic rock of hard sandstone. The 
 mountain itself was quite bare and entirely composed of 
 it. He found inscribed upon the rock several Greek and 
 Arab names, and also some Koptic characters, which 
 proved that it had been resorted to for centuries. About 
 noon the party reached the foot of the mountains called 
 Nakous, where at the foot of a ridge they beheld an insu- 
 lated peaked rock. This mountain presented upon two 
 of its sides two sandy declivities about 150 feet high, and 
 so inclined that the white and slightly .adhering sand 
 which rests upon its surface is scarcely able to support 
 itself ; and when the scorching heat of the sun destroys 
 its feeble cohesion, or when it is agitated by the smallest 
 motions, it slides down the two acclivities. These declivi- 
 ties unite behind the insulated rock, forming an acute 
 angle, and, like the adjacent surfaces, they are covered 
 with steep rocks which consist chiefly of a white and 
 friable freestone. 
 
 The first sound which greeted the ears of -the travellers 
 took place at an hour and a quarter after noon. They 
 had climbed with great difficulty as far as the sandy 
 declivity, a height of seventy or eighty feet, and had 
 rested beneath the rocks where the pilgrims are accustomed 
 to listen to the sounds. 
 
 While in the act of climbing, M. Seetzen heard the 
 sound from beneath his knees, and hence he was led to 
 think that the sliding of the sand was the cause of the 
 sound, and not the effect of the vibration which it occa- 
 sioned. At three o'clock the sound became louder, and 
 continued six minutes, and after having ceased for ten 
 minutes, it was again heard. The sound appeared to have 
 
298 LETTERS ON NATURAL MAGIC. 
 
 the greatest resemblance to that of the humming-top, 
 rising and falling like that of an Eolian harp. Believing 
 that he had discovered the true origin of the soimd, M. 
 Seetzeen was anxious to repeat the experiment, and with 
 this view he climbed with the utmost difficulty to the 
 highest rocks, and, sliding down as fast as he could, he 
 endeavoured, with the help of his hands and feet, to set 
 the sand in motion. The effect thus produced far exceeded 
 his expectetions, and the sand in rolling beneath him 
 made so loud a noise that the earth seemed to tremble to 
 such a degree that he states he should certainly have been 
 afraid if he had been ignorant of the cause. 
 
 M. Seetzen throws out some conjectures respecting the 
 cause of these sounds. Does the rolling layer of sand, 
 saps he, act like the fiddle -bow, which on being rubbed 
 upon a plate of glass raises and distributes into regular 
 figures the sand with which the plate is covered ? Does 
 the adherent and fixed layer of sand perform here the 
 part of the plate of glass, and the neighbouring rocks that 
 of the sounding body? W cannot pretend to answer 
 these questions, but we trust that some philosopher com- 
 petent to the task will have an opportunity of examining 
 these interesting phenomena with more attention, and 
 describing them with greater accuracy. 
 
 The only person, so far as I can learn, who has visited 
 El Nakous since the time of Seetzen is Mr. Gray, of 
 University College, Oxford ; but he has not added much 
 to the information acquired by his predecessor. During 
 the first visit which he made to the place, he heard at the 
 end of a quarter of an hour a low continuous murmuring 
 sound beneath his feet, which gradually changed into 
 pulsations as it became louder, so as to resemble the 
 striking of a clock, and at the end of five minutes it 
 became so strong as to detach the sand. Returning to the 
 spot next day, he heard the sound still louder than before. 
 
MUSICAL MOUNTAIN OF EL-NAKOUS. 299 
 
 He could not observe any crevices by which the external 
 air could penetrate, and as the sky was serene and the air 
 calm, he was satisfied that the sounds could not arise from 
 this cause.* 
 
 * See Edinburgh Journal of Science, No. xi. p. 153, and No. xiii. 
 p. 51. 
 
300 LETTERS ON NATURAL MAGIC. 
 
 LETTER X. 
 
 Meclmnical inventions of the ancients few in number Ancient and 
 modern feats of strength Feats of Eckeberg particularly de- 
 scribed General explanation of them Real feats of strength 
 performed by Thomas Topham Remarkable power of lifting 
 heavy persons when the lungs are inflated Belzonis feat of 
 sustaining pyramids of men Deception of walking along the 
 ceiling in an inverted position Pneumatic apparatus in the foot 
 of the house-fly for enabling it to walk in opposition to gravity 
 Description of the analogous apparatus employed by the gecko 
 lizard for the same purpose Apparatus used by the Ecliineis 
 remora or sucking fish. 
 
 THE mechanical knowledge of the ancients was principally 
 theoretical, and though they seem to have executed some 
 jninor pieces of mechanism which were sufficient to delude 
 the ignorant, yet there is no reason for believing that 
 they have executed any machinery that was capable ,of 
 exciting much surprise, either by its ingenuity or its 
 magnitude. The properties of the mechanical powers, 
 however, seem to have been successfully employed in 
 performing feats of strength which were beyond the reach 
 even of strong men, and which could not fail to excite the 
 greatest wonder when exhibited by persons of ordinary 
 size. 
 
 Firmus, a native of Seleucia, who was executed by the 
 Emperor Aurelian for espousing the cause of Zenobia, was 
 celebrated for his feats of strength. In his account of the 
 life of Firmus, who lived in the third century, Vopiscus 
 informs us, that he could suffer iron to be forged upon an 
 
FEATS OF ECKEBERG. 301 
 
 anvil placed upon his breast. In doing this he lay upon 
 his back, and resting his feet and shoulders against some 
 support, his whole body formed an arch as we shall after- 
 wards more particularly explain. Until the end of the 
 sixteenth century the exhibition of such feats does not 
 seem to have been common. About the year 1703, a 
 native of Kent of the name of Joyce exhibited such feats 
 of strength in London and other parts of England, that he 
 received the name of the second Sampson. His own 
 personal strength was very great ; but he had also dis- 
 covered, without the aid of theory, various positions of his 
 body in which men even of common strength could perform 
 very surprising feats. He drew against horses, and raised 
 enormous weights ; but as he actually exhibited his power 
 in ways which evinced the enormous strength of his own 
 muscles, all his feats were ascribed to the same cause. In 
 the course of eight or ten years, however, his methods 
 were discovered, and many individuals of ordinary strength 
 exhibited a number of his principal performances, though 
 in a manner greatly inferior to Joyce. 
 
 Some time afterwards, John Charles Van Eckeberg, a 
 native of Harzgerode in Anhalt, travelled through Europe 
 under the appellation of Sampson, exhibiting very remark- 
 able examples of his strength. This we believe is the 
 same person whose feats are particularly described by Dr. 
 Desaguliers. He was a man of the middle size, and of 
 ordinary strength ; and as Dr. Desaguliers was convinced 
 that his feats were exhibitions of skill and not of strength, 
 he was desirous of discovering his methods, and with this 
 view he went to see him accompanied with the Marquis of 
 Tullibardine, Dr. Alexander Stuart, and Dr. Pringle, and 
 his own mechanical operator. They placed themselves 
 round the German so as to be able to observe accurately 
 all that he did, and their success was so great, that they 
 were able to perform most of the feats tho same evening 
 
302 
 
 LETTERS ON NATURAL MAGIC. 
 
 by themselves, and almost all the rest when they had 
 provided the proper apparatus. Dr. Desaguliers exhi- 
 bited some of the experiments before the Royal Society. 
 and has given such a distinct explanation of the principles 
 on which they depend, that we shall endeavour to give a 
 popular account of them. 
 
 1. The performer sat upon an inclined board A B 
 placed upon a frame ODE, with his feet abutting against 
 
 Fig. 51. 
 
 the upright board C. Eound his loins was placed a strong 
 girdle F G, to the iron ring of which at G was fastened a 
 rope by means of a hook. The rope passed between his 
 legs through a hole in the board C, and several men, or 
 two horses pulling at the other end of the rope, were 
 unable to draw the performer out of his place. His hands 
 at G seemed to pull against the men, but they were of no 
 advantage to him whatever. 
 
 2. Another of the German's feats is shown in Fig. 52. 
 Having fixed the rope above mentioned to a strong post 
 at A, and made it pass through a fixed iron eye at B, to 
 the ring in his girdle, he planted his feet against the post 
 at B, and raised himself from the ground by the rope, as 
 shown in the figure. He then suddenly stretched out his 
 legs and broke the rope, falling back on a feather-bed at 
 C, spread out to receive him. 
 
 3. In imitation of Firmus, he laid himself down on the 
 ground, as shown in Fig. 53, and when an anvil A was 
 
FEATS OF ECKEBERG. 
 Ffc. 52. 
 
 303 
 
 placed upon his breast, a man hammered with all his force 
 
 the piece of iron B, with a sledge-hammer, and sometimes 
 
 Fig. 53. 
 
 tw o smiths cut in two with chisels a great cold bar of iron 
 laid upon the anvil. At other times a stone of huge 
 dimensions, half of which is shown at C, was laid upon his 
 belly, and broken with a blow of the great hammer. 
 4. The performer then placed his shoulders upon one 
 
LETTERS ON NATURAL MAGIC. 
 
 chair, and his heels upon another, as in Fig. 54, forming 
 with his back-bone, thighs, and legs, an arch springing 
 from its abutments at A and B. One or two men then 
 stood upon his belly, rising up and down while the per- 
 
 Fig. 54. 
 
 former breathed. A stone one and a half feet long, one 
 foot broad, and half a foot thick, was then laid upon his 
 belly and broken by a sledge-hammer, an operation which 
 may be performed with much less danger than when his 
 back touched the ground, as in Fig. 53. 
 
 5. His next feat was to lie down on the ground as in 
 Fig. 55. A man being then placed on his knees, he draws 
 his heels towards his body, and raising his knees, he lifts 
 up the man gradually, till having brought his knees 
 perpendicularly under him, as in Fig. 56, he raises his 
 own body up, and placing his arms around the man's legs, 
 lie rises with him, and sets him down on some low table 
 or eminence of the same height as his knees. This feat 
 he sometimes performed with two men in place of one. 
 
FEATS OF ECKEBERG. 
 
 305 
 
 Fig. 55. 
 
 Fig. 5G 
 
306 
 
 LETTERS ON NATURAL MAGIC. 
 
 6. The last, and apparently the most wonderful, per- 
 formance of the German is shown in Fig. 57, where he 
 
 i<r. 57. 
 
 appears to raise a cannon A, placed upon a scale, the 
 four ropes of the scale being fixed to a rope or chain 
 attached to his girdle in the manner already described. 
 Previous to the fixing of the ropes, the cannon and scale 
 rest upon two rollers B C, but when all is ready, the 
 two rollers are knocked from beneath the scale, and the 
 cannon is sustained by the strength of his loins. 
 
 The German also exhibited his strength in twisting 
 into a screw a flat piece of iron like A, Fig. 58. He 
 first bent the iron into a right angle as at B, and then 
 wrapping his handkerchief about its broad upper end, he 
 
FEATS OF ECKEBERG. 
 
 307 
 
 held that end in his left hand, and with his right applied 
 to the other end, twisted about the angular point, as 
 
 Fig. 58. 
 
 shown at C. Lord Tullibardine succeeded in doing the 
 same thing, and even untwisted one of the irons which 
 the German had twisted. 
 
 It would lead into details by no means popular, were 
 I to give a minute explanation of the mechanical prin 
 ciples upon which these feats depend. A few general 
 observations will perhaps be sufficient for ordinary 
 readers. The feats No. 1, 2, and 6, depend entirely on 
 the natural strength of the bones of the pelvis, which 
 form a double arch, which it would require an immense 
 force to break, by any external pressure directed to the 
 centre of the arch ; and as the legs and thighs are capable 
 of sustaining four or five thousand pounds when they 
 stand quite upright, the performer has no difficulty in 
 resisting the force of two horses, or of sustaining the 
 weight of a cannon weighing two or three thousand 
 pounds. 
 
 The feat of the anvil is certainly a very surprising one. 
 
308 LETTERS ON NATURAL MAGIC. 
 
 The difficulty, however, really consists 'in sustaining the 
 anvil, for when this is done the effect of the hammering 
 is nothing. If the anvil were a thin piece of iron, or 
 even two or three times heavier than the hammer, the 
 performer would be killed by a few blows ; but the blows 
 are scarcely felt when the anvil is very heavy, for the 
 more matter the anvil has, the greater is its inertia, and 
 it is the less liable to be struck out of its place ; for 
 when it has received by the blow the whole momentum 
 of the hammer, its velocity will be so much less than that 
 of the hammer, as its quantity of matter is greater. 
 When the blow, indeed, is struck, the man feels less of 
 the weight of the anvil than he did before, because in the 
 reaction of the stone all the parts of it round about the 
 hammer rise towards the blow. This property is illus- 
 trated by the well-known experiment of laying a stick 
 with its ends upon two drinking glasses full of water, 
 and striking the stick downwards in the middle with an 
 iron bar. The stick will in this case be broken without 
 breaking the glasses, or spilling the water. But if the 
 stick is struck upwards as if to throw it up in the air, 
 the glasses will break if the blow be strong, and if the 
 blow is not very quick, the water will be spilt without 
 breaking the glasses. 
 
 When the performer supports a man upon his belly as 
 in Fig. 54, he does it by means of the strong arch formed 
 by his backbone, and the bones of his legs and thighs. If 
 there were room for them he could bear three or four, or, 
 in their stead, a great stone, to be broken with one blow. 
 
 A number of feats of real and extraordinary strength 
 were exhibited about a century ago, in London, by 
 Thomas Topham, who was five feet ten inches high, and 
 about 31 years of age. He was entirely ignorant of any 
 of the methods for making his strength appear more 
 surprising, and he often performed by his own natural 
 
PEATS OF STRENGTH OP TOPHAM. 309 
 
 powers what he learned had been done by others by 
 artificial means. A distressing example of this occurred 
 in his attempt to imitate the feat of the German Sampson 
 by pulling against horses. Ignorant of the method which 
 we have already described, he seated himself on the 
 ground with his feet against two stirrups, and by the 
 weight of his body he succeeded in pulling against a 
 single horse ; but in attempting to pull against two horses, 
 he was lifted out of his place and one of his knees was 
 shattered against the stirrups, so as to deprive him of 
 most of the strength of one of his legs. The following 
 are the feats of real strength which Dr. Desaguliers sa\v 
 him perform. 
 
 1. Having rubbed his fingers with coal ashes to keep 
 them from slipping, he rolled up a very strong and large 
 pewter plate. 
 
 2. Having laid seven or eight short and strong pieces of 
 tobacco-pipe on the first and third finger, he broke them 
 by the force of his middle finger. 
 
 3. He broke the bowl of a strong tobacco-pipe placed 
 between his first and third finger, by pressing his fingers 
 together sideways. 
 
 4. Having thrust such another bowl under his garter, 
 his legs being bent, he broke it to pieces by the tendons 
 of his hams, without altering the bending of his leg. 
 
 5. He lifted with his teeth, and held in a horizontal 
 position for a considerable time, a table six feet long, with 
 half a hundredweight hanging at the end of it. The feet 
 of the table rested against his knees. 
 
 6. Holding in his right hand an iron kitchen poker 
 three feet long and three inches round, he struck upon his 
 bare left arm, between the elbow and the wrist, till he- 
 bent the poker nearly to a right angle. 
 
 7. Taking a similar poker, and holding the ends of it 
 in his hands, and the middle against the back of his neck, 
 
310 LETTERS ON NATURAL MAGIC. 
 
 he brought both ends of it together before him, and he 
 then pulled it almost straight again. This last feat was 
 the most difficult, because the muscles which separate the 
 arms horizontally from each other are not so strong as 
 those which bring them together. 
 
 8. He broke a rope about two inches in circumference, 
 which was partly wound about a cylinder four inches in 
 diameter, having fastened the other end of it to straps that 
 went over his shoulder. 
 
 9. Dr. Desaguliers saw him lift a rolling stone of about 
 800 Ibs. weight with his hands only, standing in a frame 
 above it, and taking hold of a frame fastened to it. Hence 
 Dr. Desaguliers gives the following relative view of the 
 strengths of individuals : 
 
 Strength of the weakest men - - 125 Ibs. 
 Strength of very strong men - - 400 
 Strength of Topham - - - 800 
 The weight of Topham was about 200. 
 
 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 II. 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 
 
LIFTING HEAVY PERSONS. ; 311 
 
 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 hand s 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 experi- 
 ment 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. 
 
 Among the remarkable exhibitions of mechanical 
 strength and dexterity, we may enumerate that of support- 
 ing pyramids of men. This exhibition is a very ancient 
 one. It is described, though not very clearly, by the 
 Koman poet Claudian, and it has derived some importance 
 
312 LETTERS ON NATUBAL MAGIC. 
 
 in modern times, in consequence of its having been per- 
 formed in various parts of great Britain by the celebrated 
 traveller Belzoni, before he entered upon the more 
 estimable career of an explorer of Egyptian antiquities. 
 The simplest form of this feat consists in placing a number 
 of men upon each other's shoulders, so that each row con- 
 sists of a man fewer till they form a pyramid terminating 
 in a single person, upon whose head a boy is sometimes 
 placed with his feet upwards. 
 
 Among the displays of mechanical dexterity, though 
 not grounded on any scientific principle, may be mentioned 
 the art of walking along the ceiling of an apartment with 
 the head downwards. This exhibition, which we have 
 witnessed in one of the London Theatres, never failed to 
 excite the wonder of the audience, although the movements 
 of the inverted performer were not such as to inspire us 
 with any high ideas of the mechanism by which they 
 were effected. The following was probably the method 
 by which the performer was carried along the ceiling. 
 Two parallel grooves or openings were made in the 
 ceiling at the same distance as the foot tracks of a person 
 walking on sand. These grooves were narrower than the 
 human foot, so as to permit a rope or chain or strong wire, 
 attached to the feet of the performer, to pass through the 
 ceiling ; where they were held by two or more persons 
 above it. In this way the inverted performer might be 
 carried along by a sliding or shuffling motion, similar to 
 that which is adopted in walking in the dark, and in 
 which the feet are not lifted from the ground. A more 
 regular motion, however, might be produced by a contriv- 
 ance for attaching the rope or chain to the sole of the 
 foot, at each step, and subsequently detaching it. In this 
 way, when the performer is pulled against the ceiling by 
 his left foot, he would lift his right foot, and having made 
 a step with it, and planted it against the grooves, the rope 
 
WALKING ALONG THE CEILING. 313 
 
 would be attached to it, and when the rope was detached 
 from the left foot, it would make a similar step, while the 
 right foot was pulled against the ceiling. These effects 
 might be facilitated and rendered more natural by attach- 
 ing to the body or to the feet of the performer strong 
 wires invisible to the audience, and by using friction 
 wheels, if a sliding motion only is required. 
 
 A more scientific method of walking upon the ceiling 
 is suggested by those beautiful pneumatic contrivances by 
 which insects, fishes, and even some lizards are enabled 
 
 to support the weight of their bodies against the force of 
 gravity. The house-fly is well known to have the power 
 of walking in an inverted position upon the ceilings of 
 rooms, as well as upon the smoothest surfaces. In this 
 case the fly does not rest upon its legs, and must therefore 
 adhere to the ceiling, either by some glutinous matter 
 upon its feet, or by the aid of some apparatus given it for 
 
 Y 
 
314 LETTERS ON NATURAL MAGIC. 
 
 that purpose. In examining the foot of the fly with a 
 po \verful microscope, it is found to consist of two conca- 
 vities, as shown in Fig. 59 and 60, the first of which is 
 copied from a drawing by G. Adams, published in 1746, 
 and the second by J. C. Keller, a painter at Nuremberg, 
 who drew it for a work published in 1766. The author 
 of this work maintains that these concavities are only 
 used when the fly moves horizontally, and that, when it 
 moves perpendicularly or on the ceiling, they are turned 
 up out of the way, and the progressive motion is effected 
 by fixing the claws shown in the figure into the irregu- 
 larities of the surface upon which the fly moves, whether 
 
 it is glass, porcelain, or any other subtance. Sir Everard 
 Home, however, supposes with great reason, that these 
 concave surfaces are (like the leathern suckers used by 
 children for lifting stones) employed to form a vacuum, 
 so that the foot adheres as it were by suction to t;he 
 ceiling, and enables the insect to support itself in an 
 inverted position. 
 
FOOT OF THE GECKO. OlD 
 
 This conclusion Sir Everard has been led to draw from 
 an examination of the foot of the Lacerta Gecko. Sir 
 Joseph Banks had mentioned to him in the year 1815, 
 that this lizard, which is a native of the island of Java, 
 comes out in the evening from the roofs of the houses, 
 and walks down the smooth, hard, polished chunam walls 
 in search of the flies which settle upon them, and which 
 are its natural food. When Sir Joseph was at Batavia, 
 he amused himself in catching this lizard. He stood close 
 to the wall at some distance from the animal, and, by 
 suddenly scraping the wall with a long flattened pole, he 
 was able to bring the animal to the ground. 
 
 Having procured from Sir Joseph a very large specimen 
 of the Gecko, which weighed 5| ounces avoirdupois, Sir 
 Everard Home was enabled to ascertain the peculiar 
 mechanism by which the feet of this animal have the 
 power of keeping hold of a smooth, hard, perpendicular 
 wall, and carry up so heavy a weight as that of its body. 
 
 The foot of the Gecko has five toes, and at the end of 
 each of them, except the thumb, is a very sharp, and highly- 
 curved claw. On the under surface of each toe are six- 
 teen transverse slits, leading to as many cavities or pockets, 
 the depth of which is nearly equal to the length of the 
 slit that forms the surface. These cavities all open 
 forwards, and the external edge of each opening is serrated 
 like the teeth of a small toothed comb. The cavities are 
 lined with a cuticle, which also covers the serrated edges. 
 
 This structure Sir Everard Home found to bear a con- 
 siderable resemblance to that portion of the head of the 
 Echineis remora, or sucking-fish, by which it attaches itself 
 to the shark, or the bottoms of ships. It is of an oval 
 form, and is surrounded by a broad, loose, moveablo edge, 
 capable of applying itself closely to the surface on which 
 it is set. It consists of two rows of cartilaginous plates, 
 connected by one edge to the surface on which they are 
 
316 LETTERS ON NATURAL MAGIC. 
 
 placed, the other, or the external edge, being serrated like 
 that in the cavities of the feet of the Gecko. The two 
 rows are separated by a thin ligamentous partition, and 
 the plates being raised or depressed by the voluntary 
 mucles form so many vacua, by means of which the adhe- 
 sion of the fish is effected. 
 
 These beautiful contrivances of Divine Wisdom cannot 
 fail to arrest the attention and excite the admiration of 
 the reader ; but though there can be little doubt that they 
 are pneumatic suckers wrought by the voluntary muscles 
 of the animals to which they belong, yet we would 
 recommend the farther examination of them to the atten- 
 tion of those who have good microscopes at their command. 
 
MECHANICAL AUTOMATA OF THE ANCIENTS 31'/ 
 
 LETTEE XI. 
 
 Mechanical automata of the ancients Moving tripods Automata of 
 Dsedalus Wooden pigeon of Archytas Automatic clock of 
 Cliarlemagne Automata made by Turrianus for Charles V. 
 Camus s automatic carriage made for Louis XIV. Degennes s 
 mechanical peacocl: Vaucanson's duck which ate and digested 
 its food Du Moulin s automata Baron Kempelen's automaton 
 chess-play ?r Drawing and writing automata Maillardet's 
 conjurer Benefits derived from the passion for automata 
 Examples of wonderful machinery for useful purposes Duncan's 
 tambouring machinery Watt's statue-turning machinery Bab- 
 bage's calculating machinery. 
 
 WE have already seen that the ancients had attained some 
 degree of perfection in the construction of automata or 
 pieces of mechanism which imitated the movements of 
 man and the lower animals. The tripods which Homer * 
 mentions as having been constructed by Vulcan for the 
 banqueting hall of the gods, advanced of their own accord 
 to the table, and again returned to their place. Self- 
 moving tripods are mentioned by Aristotle, and Philos- 
 tratus informs us, in his life of Apollonius, that this 
 philosopher saw and admired similar pieces of mechanism 
 among the sages of India. 
 
 Dasdalus enjoys also the reputation of having constructed 
 machines that imitated the motions of the human body. 
 Some of his statues are said to have moved about spon- 
 taneously, and Plato, Aristotle, and others have related 
 that it was necessary to tie them, in order to prevent them 
 
 * Iliad, Lib. xviii. 373378. 
 
818 LETTERS ON NATURAL MAGIC. 
 
 from running away. Aristotle speaks of a wooden Venus, 
 which moved about in consequence of quicksilver being 
 poured into its interior; but Callistratus, the tutor of 
 Demosthenes, states with some probability, that the statues 
 of Daedalus received their motion from the mechanical 
 powers. Beckmann is of opinion that the statues of 
 Daedalus differed only from those of the early Greeks and 
 Egyptians in having their eyes open and their feet and 
 hands free, and that the reclining posture of some, and the 
 attitude of others, " as if ready to walk/' gave rise to the 
 exaggeration that they possessed the power of locomotion. 
 This opinion, however, cannot be maintained with any 
 show of reason ; for if we apply such a principle in one 
 case, we must apply it in all, and the mind would be left 
 in a state of utter scepticism respecting the inventions of 
 ancient times. 
 
 We are informed by Aulus Gellius, on the authority of 
 Favorinus, that Archytas of Tarentum, who nourished 
 about 400 years before Christ, constructed a wooden pigeon 
 which was capable of flying. Favorinus relates, that when 
 it had once alighted, it could not again resume its flight, 
 and Aulus Gellius adds, that it was suspended by balancing, 
 and animated by a concealed aura or spirit. 
 
 Among the earliest pieces of modern mechanism was 
 the curious water-clock presented to Charlemagne by the 
 Kaliph Harun al Easchid. In the dial-plate there were 
 twelve small windows corresponding with the divisions of 
 the hours. The hours were indicated by the opening of 
 the windows, which let out little metallic balls, which 
 struck the hour by falling upon a brazen bell. The doors 
 continued open till twelve o'clock, when twelve little 
 knights, mounted on horseback, came out at the same 
 instant, and after parading round the dial, shut all the 
 windows and returned to their apartments.* 
 * Annales Loisiliani. Anno 807. 
 
TURRIANUS'S AUTOMATA. 319 
 
 The next automata of which any distinct account has 
 been preserved are those of the celebrated John Muller or 
 Regiomontauus, which have been mentioned by Kircher, 
 Baptista Porta, Gassendi, Lana, and Bishop Wilkins. 
 This philosopher is said to have constructed an artificial 
 eagle, which flew to meet the Emperor Maximilian when 
 lie arrived at Nuremberg on the 7th June, 1470. After 
 soaring aloft in the air, the eagle is stated to have met the 
 Emperor at some distance from the city, and to have 
 returned and perched upon the town gate, where it waited 
 his approach. When the Emperor reached the gate, the ' 
 eagle stretched out its wings, and saluted him by an 
 inclination of its body. Muller is likewise reported to 
 have constructed an iron fly, which was put in motion by 
 wheel-work, and which flew about and leapt upon the 
 table. At an entertainment given by this philosopher to 
 some of his familiar friends, the fly flew from his hand, 
 and after performing a considerable round, it returned 
 again to the hand of its master. 
 
 The Emperor Charles V., after his abdication of the 
 throne, amused himself in his later years with automata of 
 various kinds. The artist whom he employed was 
 Janellus Turrianus of Cremona. It was his custom after 
 dinner to introduce upon the table figures of armed men 
 and horses. Some of these beat drums, others played upon 
 flutes, while a third set attacked each other with spears. 
 Sometimes he let fly wooden sparrows, which flew back 
 again to their nest. He also exhibited corn-mills so 
 extremely small that they could be concealed in a glove, 
 yet so powerful that they could grind in a day as much 
 corn as would supply eight men with food for a day. 
 
 The next piece of mechanism of sufficient interest to 
 merit our attention is that which was made by M. Camus 
 for the amusement of Louis XIV. when a child. It con- 
 sisted of a small coach, which was drawn by two horses, 
 
320 LETTERS ON NATURAL MAGIC. 
 
 and which contained the figure of a lady within, with a 
 footman and page behind. When this machine was 
 placed at the extremity of a table of the proper size, the 
 coachman smacked his whip, and the horses instantly set 
 off, moving their legs in a natural manner, and drawing 
 the coach after them. When the coach reached the oppo- 
 site edge of the table, it turned sharply at a right angle, 
 and proceeded along the adjacent edge. As soon as it 
 arrived opposite the place where the King sat it stopped ; 
 the page descended and opened the coach door ; the lady 
 'alighted, and with a curtsey presented a petition, which 
 she held in her hand to the King. After waiting some 
 time she again curtsied and re-entered the carriage. The 
 page closed the door, and having resumed his place 
 behind, the coachman whipped his horses and drove on. 
 The footman who had previously alighted, ran after the 
 carriage and jumped up behind into his former place. 
 
 Not content with imitating the movements of animals, 
 the mechanical genius of the 17th and 18th centuries 
 ventured to perform by wheels and pinions the functions 
 of vitality. We are informed by M. Lobat, that General 
 Degennes, a French officer who defended the colony of St. 
 Christopher's against the English forces, constructed a 
 peacock, which could walk about as if alive, pick up 
 grains of corn from the ground, digest them as if they 
 had been submitted to the action of the stomach, and 
 afterwards discharge them in an altered form. Degennes 
 is said to have invented various machines of great use in 
 navigation and gunnery, and to have constructed clocks 
 without weights or springs. 
 
 The automaton of Degennes probably suggested to M. 
 Vaucanson the idea of constructing his celebrated duck, 
 which excited so much interest throughout Europe, and 
 which was perhaps the most wonderful piece of mechanism 
 that was ever made. Vaucanson's duck exactly resembled 
 
AUTOMATON CHESS-PLAYER. 321 
 
 the living animal in size and appearance. It executed 
 accurately all its movements and gestures, it ate and drank 
 with avidity, performed all the quick motions of the head 
 and throat which are peculiar to the living animal, and 
 like it, it muddled the water which it drank with its bill. 
 It produced also the sound of quacking in the most natural 
 manner. In the anatomical structure of the duck, the 
 artist exhibited the highest skill. Every bone in the real 
 duck had its representative in the automaton, and its 
 wings were anatomically exact. Every cavity, apophysis, 
 and curvature was imitated, and each bone executed its 
 proper movements. When corn was thrown down before 
 it, the duck stretched out its neck to pick it up, it swallowed 
 it, digested it, and discharged it, in a digested condition. 
 The process of digestion was effected by chemical solution, 
 and not by trituration, and the food digested in the 
 stomach was conveyed away by tubes to the place of its 
 discharge. 
 
 The automata of Vaucanson were imitated by one Du 
 Moulin, a silversmith, who travelled with them through 
 Germany in 1752, and who died at Moscow in 1765. 
 Beckmann informs us that he saw several of them after 
 the machinery had been deranged ; but that the artificial 
 duck, which he regarded as the most ingenious, was still 
 able to eat, drink, and move. Its ribs, which were made 
 of wire, were covered with duck's feathers, and the motion 
 was communicated through the feet of the duck by means 
 of a cylinder and fine chains like that of a watch. 
 
 Ingenious as all these machines are, they sink into 
 insignificance when compared with the automaton chess- 
 player, which for a long time astonished and delighted 
 the whole of Europe. In the year 1769, M. Kempelen, a 
 gentleman of Presburg in Hungary, constructed an auto- 
 maton chess-player, the general appearance of which is 
 shown in the annexed figures. The chess-player is a 
 
322 
 
 LETTERS ON NATURAL MAGIC. 
 
 figure as large as life, clothed in a Turkish dress, sitting 
 behind a large square chest or box three feet and a half 
 long, two feet deep, and two and a half high. The machine 
 runs on casters, and is either seen on the floor when the 
 doors of the apartment are thrown open, or is wheeled 
 into the room previous to the commencement of the exhi- 
 bition. The Turkish chess-player sits on a chair fixed to 
 the square chest : his right arm rests on the table, and in 
 the left he holds a pipe, which is removed during the 
 game, as it is with this hand that he makes the moves. A 
 chess-board, eighteen inches square, and bearing the usual 
 number of pieces, is placed before the figure. The 
 
 Fig. 61. 
 
 Fig. 62. 
 
 exhibitor then announces to the spectators his intention of 
 showing them the mechanism of the automaton. For this 
 purpose he unlocks the door A, Fig. 61, and exposes to 
 view a small cupboard lined with black or dark coloured 
 cloth, and containing cylinders, levers, wheels, pinions, 
 and different pieces of machinery, which have the appearance 
 of occupying the whole space. He next opens the door 
 B, Fig. 62, at the back of the same cupboard, and holding 
 a lighted candle at the opening, he still further displays 
 the enclosed machinery to the spectators, placed in front 
 of A, Fig. 61. When the candle is withdrawn, the door 
 
AUTOMATON CHESS-PLAYER. 323 
 
 B is then locked ; and the exhibitor proceeds to open the 
 drawer G, G, Fig. 61, in front of the chest. Out of this 
 drawer he takes a small box of counters, a set of chess- 
 men, and a cushion for the support of the automaton's 
 arm, as if this was the sole object of the drawer. The 
 two front doors, C, C, of the large cupboard, Fig. 61, are 
 then opened, and at the back-door D of the same cup- 
 board, Fig. 62, the exhibitor applies a lighted candle, as 
 before, for the purpose of showing its interior, which is 
 lined with dark cloth like the other, and contains only a 
 few pieces of machinery. The chest is now wheeled 
 round, as in Fig. 62 : the garments of the figure are 
 lifted up, and the door E in the trunk, and another door 
 F in the thigh, are opened, the doors B and D having 
 been previously closed. When this exhibition of the 
 interior of the machine is over, the chest is wheeled back 
 into its original position on the floor. The doors A, C, C, 
 in front, and the drawer G, G, are closed and locked, and 
 the exhibitor, after occupying himself for some time at the 
 back of the chest, as if he were adjusting the mechanism, 
 removes the pipe from the hand of the figure, and winds 
 up the machinery. 
 
 The automaton is now ready to play, and when an 
 opponent has been found among the company, the figure 
 takes the first move. At every move made by the 
 automaton, the wheels of the machine are heard in action ; 
 the figure moves its head, and seems to look over every 
 part of the chess-board. When it gives check to its 
 opponent, it shakes its head thrice, and only twice when it 
 checks the queen. It likewise shakes its head when a 
 false move is made, replaces the adversary's piece on the 
 square from which it was taken, and takes the next move 
 itself. In general, though not always, the automaton 
 wins the game. 
 
 During the progress of the game, the exhibitor often 
 
324 LETTEKS ON NATURAL MAGIC. 
 
 stood near the machine, and wound it up like a clock 
 after it had made ten or twelve moves. At other times he 
 went to a corner of the room, as if it were to consult a 
 small square box, which stood open for this purpose. 
 
 The chess-playing machine, as thus described, was 
 exhibited after its completion in Presburg, Vienna, and 
 Paris, to thousands, and in 1783 and 1784 it was exhibited 
 in London and different parts of England, without the 
 secret of its movements having been discovered. Its 
 ingenious inventor, who was a gentleman and a man of 
 education, never pretended that the automaton itself 
 really played the game. On the contrary, he distinctly 
 stated, " that the machine was a bagatelle, which was not 
 without merit in point of mechanism, but that the effects 
 of it appeared so marvellous only from the ^boldness of 
 the conception, and the fortunate choice of the methods 
 adopted for promoting the illusion." 
 
 Upon considering the operations of this automaton, it 
 must have been obvious that the game of chess was 
 performed either by a person enclosed in the chest, or by 
 the exhibitor himself. The first of these hypotheses was 
 ingeniously excluded by the display of the interior of the 
 machine, for as every part contained more or less 
 machinery, the spectator invariably concluded that the 
 smallest dwarf could not be accommodated within, and 
 this idea was strengthened by the circumstance, that no 
 person of this description could be discovered in the suite 
 of the exhibitor. Hence the conclusion was drawn, that 
 the exhibitor actuated the machine either by mechanical 
 means conveyed through its feet, or by a magnet concealed 
 in the body of the exhibitor. That mechanical communi- 
 cation was not formed between the exhibitor and the 
 figure, was obvious from the fact, that no such communi- 
 cation was visible, and that it was not necessary to place 
 the machine on any particular part of the floor. Hence 
 
AUTOMATON CHESS-PLAYER. 325 
 
 the opinion became very prevalent that the agent was a 
 magnet ; but even this supposition was excluded, for the 
 exhibitor allowed a strong and well-armed loadstone to 
 be placed upon the machine during the progress of the 
 game. Had the moving power been a magnet, the whole 
 action of the machine would have been deranged by the 
 approximation of a loadstone concealed in tlie pockets of 
 any of the spectators. 
 
 As Baron Kempelen himself had admitted that there 
 was an illusion connected with the performance of the 
 automaton, various persons resumed the original conjecture, 
 that it was actuated by a person concealed in its interior, 
 who either played the game of chess himself, or performed 
 the moves which the exhibitor indicated by signals. A 
 Mr. J. F. Freyhere of Dresden published a book on the 
 subject in 1789, in which he endeavoured to explain, by 
 coloured plates, how the effect was produced; and he 
 concluded, " that a well-taught boy, very thin and tall of 
 his age (sufficiently so that he could be concealed in a 
 drawer almost immediately under the chess-board), agitated 
 the whole." 
 
 In another pamphlet which had been previously pub- 
 lished at Paris in 1785, the author not only supposed that 
 the machine was put in motion by a dwarf, a famous chess- 
 player, but he goes so far as to explain the manner in 
 which he could be accommodated within the machine. 
 The invisibility of the dwarf when the doors were opened 
 was explained by his legs and thighs being concealed in 
 two hollow cylinders, while the rest of his body was out 
 of the box, and hid by the petticoats of the automaton. 
 When the doors were shut the clacks produced by the 
 swivel of a ratchet-wheel permitted the dwarf to change 
 his place and return to the box unheard ; and while the 
 machine was wheeled about the room, the dwarf had an 
 opportunity of shutting the trap through which he passed 
 
326 LETTERS ON NATURAL MAGIC. 
 
 into the machine. The interior of the figure was next 
 shown, and the spectators were satisfied that the box con- 
 tained no living agent. 
 
 Although these views were very plausible, yet they 
 were never generally adopted ; and when the automaton 
 was exhibited in Great Britain in 1819 and 1820, by 
 M. Maelzel, it excited as intense an interest as when it 
 was first produced in Germany. There can be little 
 doubt, however, that the secret has been discovered ; and 
 an anonymous writer has shown in a pamphlet, entitled 
 " An attempt to analyse the Automaton Chess-player of M. 
 Kempelen," that it is capable of accommodating an 
 ordinary-sized man ; and he has explained in the clearest 
 manner how the inclosed player takes all the different 
 positions, and performs all the motions which are necessary 
 to produce the effects actually observed. The following 
 is the substance of his observations : 
 
 The drawer G G when closed does not extend to the 
 back of the chest, but leaves a space O behind it (see 
 Figs. 69, 70, and 71), fourteen inches broad, eight inches 
 high, and three feet eleven inches long. This space is 
 never exposed to the view of spectators. The small 
 cupboard seen at A is divided into two parts by a door or 
 screen I, Fig. 68, which is moveable upon a hinge, and is 
 so constructed that it closes at the same instant that B is 
 closed. The whole of the front compartment as far as I is 
 occupied with the machinery H. The other compartment 
 behind I is empty, and communicates with the space () 
 behind the drawer, the floor of this division being removed. 
 The back of the great cupboard C C is double, and the 
 part P Q,-to which the quadrants are attached, moves on 
 a joint Q, at the upper part, and forms when raised an 
 opening S, between the two cupboards, by carrying wifli 
 it part of the partition E, which consists of cloth tightly 
 stretched. The false back is shown closed in Fig. 69, 
 
AUTOMATON CHESS-PLAYER. 
 
 327 
 
 while Fig. 70 shows the same back raised, so as to form 
 the opening S between the chambers. 
 
 When the spectator is allowed to look into the trunk 
 of the figure by lifting up the dress, as in Fig. 70, it will 
 be observed that a great part of the space is occupied by 
 an inner trunk N, Fig. 70, 71, which passes off to the 
 back in the form of an arch, and conceals from the 
 spectators a portion of the interior. This inner trunk N 
 opens and communicates with the chest by an aperture T, 
 Fig. 72, about twelve inches broad and fifteen high. 
 When the false back is raised, the two cupboards, the 
 
 Fig. 63. 
 
 Fig. 64. 
 
 trunk N, and the space behind the drawer, are all con- 
 nected together. 
 
 The construction of the interior being thus understood, 
 the chess-player may be introduced into the chest through 
 the sliding panel U, Fig. 69. He will then raise the 
 false back of the large cupboard, and assume the position 
 represented by the shaded figure in Fig. 63 and 64. 
 Things being in this state, the exhibitor is ready to begin 
 his process of deception. He first opens the door A of 
 the small cupboard, and from the crowded and very 
 ingenious disposition of the machinery within it, the eye 
 is unable to penetrate far beyond the opening, and the 
 spectator concludes without any hesitation that the whole 
 
328 LETTERS ON NATURAL MAGIC. 
 
 of the cupboard is filled, as it appears to be, with similar 
 machinery. This false conclusion is greatly corroborated 
 by observing the glimmering light which plays among 
 the wheel-work when the door B is opened, and a candle 
 held at the opening. This mode of exhibiting the interior 
 of the cupboard satisfies the spectator also that no opaque 
 body capable of holding or concealing any of the parts 
 of a hidden agent is interposed between the light and the 
 observer. The door B is now locked and the screen I 
 closed, and as this is done at the time that the light is 
 withdrawn it will wholly escape observation. 
 
 The door B is so constructed as to close by its own 
 weight, but as the head of the chess-player will soon be 
 placed very near it, the secret would be disclosed if, in 
 turning round, the chest door should by any accident fly 
 open. This accident is prevented by turning the key, 
 and, lest this little circumstance should excite notice, it 
 would probably be regarded as accidental, as the keys 
 were immediately wanted for the other locks. 
 
 As soon as the door B is locked, and the screen I closed, 
 the secret is no longer exposed to hazard, and the ex- 
 hibitor proceeds to lead the minds of the spectators still 
 farther from the real state of things. The door A is left 
 open to confirm the opinion that no person is concealed 
 within, and that nothing can take place in the interior 
 without being observed. 
 
 The drawer G G is now opened, apparently for the 
 purpose of looking at the chess-men, cushion and counters 
 which it contains ; but the real object of it is to give time 
 to the player to change his position, as shown in the 
 annexed figure, and to replace the false back and partition 
 preparatory to the opening of the great cupboard. The 
 chess-player, as the figure shows, occupies with his body 
 the back compartment of the small cupboard, while his 
 legs and thighs are contained in the space 0, behind the 
 
AUTOMATON CHESS-PLAYER. 329 
 
 drawer G G, his body being concealed by the screen I, 
 and his limbs by the drawer G G. 
 
 The great cupboard C is now opened, and there is so 
 little machinery in it that the eye instantly discovers that 
 no person is concealed in it. To make this more certain, 
 however, a door is opened at the back, and a lighted 
 candle held to it, to allow the spectators to explore every 
 corner and recess. 
 
 Fig. 65. 
 
 The front doors of the great and small cupboard being 
 left opened, the chest is wheeled round to show the trunk 
 of the figure, and the bunch of keys is allowed to remain 
 in the door D, as the apparent carelessness of such a pro- 
 ceeding will help to remove any suspicion which may 
 have been excited by the locking of the door B. 
 
 When the drapery of the figure has been raised, and 
 the doors E and F in the trunk and thigh opened, the 
 chest is wheeled round again into its original position, 
 and the doors E and F closed. In the mean time the 
 player withdraws his legs from behind the drawer, as he 
 cannot so easily do this when the drawer G G is pushed in. 
 
 In all these operations, the spectator flatters himself 
 that he has seen in succession every part of the chest, 
 while in reality some parts have been wholly concealed 
 from his view, and others but imperfectly shown, while at 
 
 z 
 
330 
 
 LETTERS ON NATURAL MAGIC. 
 
 the present time nearly half of the chest is excluded from 
 view. 
 
 When the drawer G G is pushed in, and the doors A 
 and C closed, the exhibitor adjusts the machinery at the 
 back, in order to give time to the player to take the posi- 
 tion shown in a front view in Fig. 66, and in profile in 
 Fig. 67. In this position he will experience no difficulty 
 in executing every movement made by the automaton. 
 As his head is above the chess-board, he will see through 
 
 Fig. 66. 
 
 Fig. 67. 
 
 the waistcoat of the figure, as easily as through a veil, the 
 whole of the pieces on the board, and he can easily take 
 up and put down a chess-man without any other mechan- 
 ism than that of a string communicating with the finger 
 of the figure. His right hand being within the chest may 
 be employed to keep in motion the wheel-work for pro- 
 ducing the noise which is heard during the moves, and to 
 perform the other movements of the figure, such as that 
 of moving the head, tapping on the chest, &c. 
 
 A very ingenious contrivance is adopted to facilitate 
 the introduction of the player's left arm into the arm of 
 the figure. To permit this, the arm of the figure requires 
 to be drawn backwards ; and for the purpose of conceal- 
 ing, and at the same time explaining this strained attitude, 
 
AUTOMATON CHESS-PLAYER. 
 
 331 
 
 a pipe is ingeniously placed in the automaton's hand- 
 For this reason the pipe is not removed till all the other 
 arrangements are completed. When everything has been 
 thus prepared, the pipe is taken from the figure, and the 
 exhibitor winds up as it were the inclosed machinery, for 
 the double purpose of impressing upon the company the 
 belief that the effect is produced by machinery, and of 
 giving a signal to the player to put in motion the head of 
 the automaton. 
 
 Fig. 68. 
 
 Fig. 69. 
 
 This ingenious explanation of the chess automaton is, 
 our author states, greatly confirmed by the regular and 
 undeviating mode of disclosing the interior of the chest ; 
 and he also shows that the facts which have been observed 
 respecting the winding-up of the machine " afford positive 
 proof that the axis turned by the key is quite free and 
 unconnected either with a spring or weight, or any system 
 of machinery." 
 
 In order to make the preceding description more intel- 
 ligible, I shall add the following more detailed explana- 
 tion of the figures. 
 
 Fig. 61 is a perspective view of the automaton seen in 
 front with all the doors thrown open. 
 
 Fig. 62 is an elevation of the automaton, as seen from 
 behind. 
 
332 
 
 LETTERS ON NATURAL MAGIC. 
 
 Fig. 63 is an elevation of the front of the chest, the 
 shaded figure representing the enclosed player in his 
 first position, or when the door A is opened. 
 
 Fig. 64 is a side elevation, the shaded figure represent- 
 ing the player in the same position. 
 
 Fig. 65 is a front elevation, the -'shaded figure showing 
 the player in his second position, or that which he takes 
 after the door B and screen I are closed, and the great 
 cupboard opened. 
 
 Fig. 66 is a front elevation, the shaded figure showing 
 the player in his third position, or that in which he plays 
 the game. 
 
 Fig. 70. 
 
 Fig. 71. 
 
 Fig. 67 is a side elevation, showing the figure in the 
 same position. 
 
 Fig. 68 is an horizontal section of the chest through 
 the line W W in Fig. 66. 
 
 Fig. 69 is a vertical section of the chest through the 
 line X X in Fig. 68. 
 
 Fig. 70 is a vertical section through the line Y Y, 
 Fig. 66 showing the false back closed. 
 
 Fig. 71 is a similar vertical section showing the false 
 back raised. ^ 
 
 The following letters of reference are employed in all 
 the figures : 
 
 A. Front door of the small cupboard. 
 
 B. Back door of ditto. 
 
DRAWING AND WRITING AUTOMATA. 333 
 
 C C. Front doors of large cupboard. 
 
 D. Back door of ditto. 
 
 E. Door of ditto. 
 
 F. Door of the thigh. 
 G G. The drawer. 
 
 H. Machinery in front of the small cupboard. 
 
 I. Screen behind the machinery. 
 
 K. Opening caused by the removal of part of the floor 
 of the small cupboard. 
 
 L. A box which serves to conceal an opening in the 
 floor of the large cupboard, made to facilitate the first 
 position; and which also serves as a seat for the third 
 position. 
 
 M. A similar box to receive the toes of the player in 
 the first position. 
 
 N. The inner chest filling up part of the trunk. 
 
 O. The space behind the drawer. 
 
 P Q. The false back turning on a joint at Q. 
 
 E. Part of the partition formed of cloth stretched tight, 
 which is carried up by the false back to form the opening 
 between the chambers. 
 
 S. The opening between the chambers. 
 
 T. The opening connecting the trunk and chest, which 
 is partly concealed by the false back. 
 
 U. Panel which is slipt aside to admit the player. 
 
 Various pieces of mechanism of wonderful ingenuity 
 have been constructed for the purposes of drawing and 
 writing. One of these, invented by M. Le Droz, the son 
 of the celebrated Droz of Chaux le Fonds, has been de- 
 scribed by Mr. Collinson. The figure was the size of life. 
 It held in its hand a metallic style, and when a spring was 
 touched, so as to release a detent, the figure immediately 
 began to draw upon a card of Dutch vellum previously 
 laid under its hand. After the drawing was executed on 
 the first card, the figure rested. Other five cards were 
 
334 LETTERS ON NATURAL MAGIC. 
 
 then put in in succession, and upon these it delineated in 
 the same manner different subjects. On the first card it 
 drew "elegant portraits, and likenesses of the king and 
 queen facing each other;" and Mr. Collinson remarks, 
 that it was curious to observe with what precision the 
 figure lifted up its pencil in its transition from one point 
 of the drawing to another without making the slightest 
 mistake. 
 
 M. Maillardet has executed an automaton which both 
 writes and draws. The figure of a boy kneeling on one 
 knee holds a pencil in his hand. When the figure begins 
 to work, an attendant dips the pencil in ink, and adjusts 
 the drawing-paper upon a brass tablet. Upon touching a 
 spring, the figure proceeds to write, and when the line is 
 finished its hand returns to dot and stroke the letters 
 when necessary. In this manner it executes four beauti- 
 ful pieces of writing in French and English, and three 
 landscapes, all of which occupy about one hour. 
 
 One of the most popular pieces of mechanisn which we 
 have seen is the magician constructed by M. Maillardet 
 for the purpose of answering certain given questions. A 
 figure, dressed like a magician, appears seated at the 
 bottom of a wall, holding a wand in one hand and a book 
 in the other. A number of questions ready prepared are 
 inscribed on oval medallions, and the spectator takes any 
 of these which he chooses, and to which he wishes an 
 answer ; and having placed it in a drawer ready to receive 
 it, the drawer shuts with a spring till the answer is returned. 
 The magician then rises from his seat, bows his head, 
 describes circles with his wand, and, consulting the book 
 as if in deep thought, he lifts it toward his face. Having 
 thus appeared to ponder over the proposed question, he 
 raises his wand, and striking with it the wall above his 
 head, two folding-doors fly open, and display an appropri- 
 ate answer to the question. The doors again close, the 
 
MAILLAKDET'S AUTOMATA. 335 
 
 magician resumes his original position, and the drawer 
 opens to return the medallion. There are twenty of these 
 medallions, all containing different questions, to which 
 the magician returns the most suitable and striking 
 answers. The medallions are thin plates of brass of an 
 elliptical form, exactly resembling each other. Some of 
 the medallions have a question inscribed on each side, 
 both of which the magician answers in succession. If the 
 drawer is shut without a medallion being put into it, the 
 magician rises, consults his book, shakes his head, and re- 
 sumes his seat. The folding-doors remain shut, and the 
 drawer is returned empty. If two medallions are put into 
 the drawer together, an answer is returned only to the lower 
 one. When the machinery is wound up, the movements 
 continue about an hour, during which time about fifty ques- 
 tions may be answered. The inventor stated, that the 
 means by which the different medallions acted upon the 
 machinery, so as to produce the proper answers to the 
 questions which they contained, were extremely simple.* 
 
 The same ingenious artist has constructed various other 
 automata representing insects and other animals. One of 
 these was a spider entirely made of steel, which exhibited 
 all the movements of the animal. It ran on the surface of 
 a table during three minutes, and to prevent it from run- 
 ning off, its course always tended towards the centre of the 
 table. He constructed likewise a caterpillar, a lizard, 
 a mouse, and a serpent. The serpent crawls about in 
 every direction, opens its mouth, hisses and darts out its 
 tongue. 
 
 Ingenious and beautiful as all these pieces of mechanism 
 are, and surprising as their effects appear even to scientific 
 spectators, the principal object of their inventors was to 
 astonish and amuse the public. We should form an 
 
 * See the Edinburgh Encyclopedia, Art. ANDROIDES, Vol. ii. 
 p. 66. 
 
336 LETTERS ON NATURAL MAGIC. 
 
 erroneous judgment, however, if we supposed that this was 
 the only result of the ingenuity which they displayed. The 
 passion for automatic exhibitions which characterised the 
 eighteenth century gave rise to the most ingenious mechani- 
 cal devices, and introduced among the higher orders of 
 artists habits of nice and accurate execution in the formation 
 of the most delicate pieces of machinery. The same combi- 
 nation of the mechanical powers which made the spider 
 crawl, or which waved the tiny rod of the magician, con- 
 tributed in future years to purposes of higher import. 
 Those wheels and pinions, which almost eluded our senses 
 by their minuteness, reappeared in the stupendous 
 mechanism of our spinning-machines and our steam- 
 engines. The elements of the tumbling puppet were 
 revived in the chronometer, which now conducts our navy 
 through the ocean; and the shapeless wheel which 
 directed the hand of the drawing automaton has served in 
 the present age to guide the movements of the tambouring 
 engine. Those mechanical wonders which in one century 
 enriched only the conjurer who used them, contributed in 
 another to augment the wealth of the nation ; and those 
 automatic toys which once amused the vulgar, are now 
 employed in extending the power and promoting the 
 civilization of our species. In whatever way, indeed, the 
 power of genius may invent or combine, and to whatever 
 low or even ludicrous purposes that invention or combina- 
 tion may be originally applied, society receives a gift 
 which it can never lose ; and though the value of the 
 seed may not be at once recognized, and though it may lie 
 long unproductive in the ungenial till of human knowledge, 
 it will some time or other evolve its germ, and yield to 
 mankind its natural and abundant harvest. 
 
 Did the limits of so popular a volume as this ought to 
 be permit it, I should have proceeded to give a general 
 description of some of these extraordinary pieces of 
 
MR. DUNCANS TAMBOURING MACHINE. 
 
 337 
 
 machinery, the construction and effects of which never 
 fail to strike the spectator with surprise. This, however, 
 would lead me into a field too extensive, and I shall 
 therefore confine myself to a notice of three very remark- 
 able pieces of mechanism which are at present very little 
 known to the general reader, viz., the tambouring machine 
 of Mr. Duncan, the statue-turning machine of Mr. Watt, 
 and the calculating machinery of Mr. Babbage. 
 
 The tambouring of muslins, or the art of producing 
 upon them ornamental flowers and figures, has been long 
 known and practised in Britain, as well as in other 
 countries; but it was not long before the year 1790 that 
 it became an object of general manufacture in the west of 
 Scotland, where it was chiefly carried on. At first it was 
 under the direction of foreigners ; but their aid was not 
 long necessary, and it speedily extended to such a degree 
 as to occupy, either wholly or partially, more than 20,000 
 females. Many of these labourers lived in the neighbour- 
 hood of Glasgow, which was the chief seat of the manufac- 
 ture ; but others were scattered through every part of 
 Scotland, and supplied by agents with work and money. 
 In Glasgow, a tambourer of ordinary skill could not in 
 general earn more than five or six shillings a week by 
 constant application ; but to a labouring artisan, who had 
 several daughters, even these low wages formed a source 
 of great wealth. At the age of five years, a child capable 
 of handling a needle was devoted to tambouring, even 
 though it could not earn more than a shilling or two in a 
 week ; and the consequence of this was, that female 
 children were taken from school, and rendered totally 
 unfit for any social or domestic duty. The tambouring 
 population was therefore of the worst kind, and it must 
 have been regarded as a blessing rather than as a calamity, 
 when the work which they performed was entrusted to 
 regular machinery. 
 
338 LETTERS ON NATURAL MAGIC. 
 
 Mr. John Duncan of Glasgow, the inventor of the 
 tambouring machinery, was one of those unfortunate 
 individuals who benefit their species without benefiting 
 themselves, and who died in the meridian of life the 
 victim of poverty and of national ingratitude. He con- 
 ceived the idea of bringing into action a great number of 
 needles at the same time, in order to shorten the process 
 by manual labour, but he at first was perplexed about the 
 diversification of the pattern. This difficulty, however, he 
 soon surmounted by employing two forces at right angles 
 to each other, which gave him a new force in the direction 
 of the diagonal of the parallelogram, whose sides were 
 formed by the original forces. His first machine was 
 very imperfect ; but after two years' study he formed a 
 company, at whose expense six improved machines were 
 put in action, and who secured the invention by a patent. 
 At this time the idea of rendering the machine automatic 
 had scarcely occurred to him; but he afterwards suc- 
 ceeded in accomplishing this great object, and the tam- 
 bouring machines were placed under the surveillance of a 
 steam-engine. Another patent was taken for these 
 improvements. The reader who desires to have a minute 
 account of these improvements, and of the various parts of 
 the machinery, will be amply gratified by perusing the 
 inventor's own account of the machinery in the article 
 CHAINWOKK in the Edinburgh Encyclopaedia. At present 
 it will be sufficient to state, that the muslin to be tam- 
 boured was suspended vertically in a frame, which was 
 capable of being moved both in a vertical and a horizontal 
 direction. Sixty or more needles lying horizontal occu- 
 pied a frame in front of the muslin web. Each of these 
 working-needles, as 'they are called, was attended by a 
 feeding-needle, which by a circular motion round the 
 working-needle lodged upon the stem of the latter the loop 
 of the thread. The sixty needles then penetrated the web, 
 
MR. WATT'S STATUE-TURNING MACHINE. 339 
 
 and in order that they might return again without injuring 
 the fabric, the barb or eye of the needle, which resembled 
 the barb of a fishing hook, was shut by a slider. The 
 muslin web then took a new position by means of the 
 machinery that gave it its horizontal and vertical motion, 
 so that the sixty needles penetrated it, at their next move- 
 ment, at another point of the figure or flower. This 
 operation went on till sixty flowers were completed. The 
 web was then slightly wound up, that the needles might 
 be opposite that part of it on which they were to work 
 another row of flowers. 
 
 The flowers were generally at an inch distance, and the 
 rows were placed so that the flowers formed what are 
 called diamonds. There were seventy-two rows of flowers 
 in a yard, so that in every square yard there were nearly 
 4000 flowers, and in every piece of ten yards long 40,000. 
 The number of loops or stitches in a flower varied with 
 the pattern, but on an average there was about thirty. 
 Hence the number of stitches in a yard was 120,000, and 
 the number in a piece was 1,200,000. The average work 
 done in a week by one machine was fifteen yards, or 
 60,000 flowers, or 1,800,000 stitches, and by comparing 
 this with the work done by one person with the hand, it 
 appeared that the machine enabled one person to do the 
 work of twenty-four persons. 
 
 One of the most curious and important applications of 
 machinery to the arts which has been suggested in modern 
 times was made by the late Mr. Watt, in the construction 
 of a machine for copying or reducing statues and sculp- 
 ture of all kinds. The art of multiplying busts and 
 statues, by casts in plaster of Paris, has been the means 
 of diffusing a knowledge of this branch of the fine arts ; 
 but from the fragile nature of the material, the copies 
 thus produced were unfit for exposure to the weather, and 
 therefore ill calculated for ornamenting public buildings, 
 
340 LETTERS ON NATURAL MAGIC. 
 
 or for perpetuating the memory of public achievements. 
 A machine, therefore, which is capable of multiplying 
 the labours of the sculptor in the durable materials of 
 marble or of brass was a desideratum of the highest value, 
 and one whicli could have been expected only from a 
 genius of the first order. During many years Mr. Watt 
 carried on his labours in secret, and he concealed even his 
 intention of constructing such a machine. After he had 
 made considerable progress in its execution, and had 
 thought of securing his invention by a patent, he learned 
 that an ingenious individual in his own neighbourhood 
 had been long occupied in the same pursuit; and Mr. 
 Watt informed me, that he had every reason to believe 
 that this gentleman was entirely ignorant of his labours. 
 A proposal was then made that the two inventors should 
 combine their talents, and secure the privilege by a joint 
 patent ; but Mr. Watt had experienced so frequently the 
 fatal operation of our patent laws, that he saw many diffi- 
 culties in the way of such an arrangement, and he was 
 unwilling, at his advanced age, to embark in a project so 
 extensive, and which seemed to require for its successful 
 prosecution all the ardour and ambition of a youthful 
 mind. The scheme was therefore abandoned ; and such 
 is the unfortunate operation of our patent laws, that the 
 circumstance of two individuals having made the same 
 invention has prevented both from bringing it to perfec- 
 tion, and conferring a great practical benefit upon their 
 species. The machine which Mr. Watt had constructed 
 had actually executed some excellent pieces of work. I 
 have seen in his house at Heathfield copies of basso 
 relievos, and complete statues of a small size ; and some 
 of his friends have in their possession other specimens of 
 its performance. 
 
 Of all the machines which have been constructed in 
 modern times, the calculating machine is doubtless the 
 
MR. BABBAGE'S CALCULATING MACHINE. 341 
 
 most extraordinary. Pieces of mechanism for perform- 
 ing particular arithmetical operations have been long ago 
 constructed, but these bear no comparison either in 
 ingenuity or in magnitude to the grand design conceived 
 and nearly executed by Mr. Babbage. Great as the power 
 of mechanism is known to be, yet we venture to say that 
 many of the most intelligent of our readers will scarcely 
 admit it to be possible that astronomical and navigation 
 tables can be accurately computed by machinery ; that 
 the machine can itself correct the errors which it may 
 commit; and that the results of its calculations, when 
 absolutely free from error, can be printed off, without the 
 aid of human hands, or the operation of human intelli- 
 gence. All this, however, Mr. Babbage's machine can do ; 
 and as I have had the advantage of seeing it actually 
 calculate, and of studying its construction with Mr. 
 Babbage himself, I am able to make the above statement 
 on personal observation. The calculating machine now 
 constructing under the superintendence of the inventor 
 has been executed at the expense of the British Govern- 
 ment, and is of course their property. It consists essen- 
 tially of two parts, a calculating part, and a printing part, 
 both of which are necessary to the fulfilment of Mr. 
 Babbage's views, for the whole advantage would be lost 
 if the computations made by the machine were copied by 
 human hands and transferred to types by the common 
 process. The greater part of the calculating machinery 
 is already constructed, and exhibits workmanship of such 
 extraordinary skill and beauty that nothing approaching 
 to it has been witnessed. In order to execute it, parti- 
 cularly those parts of the apparatus which are dissimilar 
 to any used in ordinary mechanical constructions, tools 
 and machinery of great expense and complexity have been 
 invented and constructed ; and in many instances contriv- 
 ances of singular ingenuity have been resorted to, which 
 
342 LETTERS ON NATURAL MAGIC. 
 
 cannot fail to prove extensively useful in various branches 
 of the mechanical arts. 
 
 The drawings of this machinery, which form a large 
 part of the work, and on which all the contrivance has 
 been bestowed, and all the alterations made, cover upwards 
 of 400 square feet of surface, and are executed with ex- 
 traordinary care and precision. 
 
 In so complex a piece of mechanism, in which inter- 
 rupted motions are propagated simultaneously along a 
 great variety of trains of mechanism, it might have been 
 supposed that obstructions would arise, or even incompa- 
 tibilities occur, from the impracticability of foreseeing all 
 the possible combinations of the parts ; but this doubt has 
 been entirely removed, by the constant employment of a 
 system of mechanical notation invented by Mr. Babbage, 
 which places distinctly in view, at every instant, the pro- 
 gress of motion through all the parts of this or any other 
 machine, and by writing down in tables the times required 
 for all the movements, this method renders it easy to 
 avoid all risk of two opposite actions arriving at the same 
 instant at any part of the engine. 
 
 In the printing part of the machine less progress has 
 been made in the actual execution than in the calculating 
 part. The cause of this is the greater difficulty of its 
 contrivance, not for transferring the computations from 
 the calculating part to the copper or other plate destined 
 to receive it, but for giving to the plate itself that number 
 and variety of movements which the forms adopted in 
 printed tables may call for in practice. 
 
 The practical object of the calculating engine is to 
 compute and print a great variety and extent of astronomi- 
 cal and navigation tables, which could not be done with- 
 out enormous intellectual and manual labour, and which, 
 even if executed by such labour, could not be calculated 
 with the requisite accuracy. Mathematicians, astronomers, 
 
ME. BABBAGE'S CALCULATING MACHINE. 343 
 
 and navigators do not require to be informed of the real 
 value of such tables ; but it may be proper to state, for 
 the information of others, that seventeen large folio 
 volumes of logarithmic tables alone were calculated at an 
 enormous expense by the French Government ; and that 
 the British Government regarded these tables to be of 
 such national value that they proposed to the French 
 Board of Longitude to print an abridgment of them at the 
 joint expense of the two nations, and offered to advance 
 5000Z. for that purpose. Besides logarithmic tables, Mr. 
 Babbage's machine will calculate tables of the powers and 
 products of numbers, and all astronomical tables for 
 determining the positions of the sun, moon, and planets ; 
 and the same mechanical principles have enabled him to 
 integrate innumerable equations of finite differences ; that 
 is, when the equation of differences is given, he can, by 
 setting an engine, produce at the end of a given time any 
 distant term which may be required, or any succession of 
 terms commencing at a distant point. 
 
 Besides the cheapness and celerity with which this 
 machine will perform its work, the absolute accuracy of the 
 printed results deserves especial notice. By peculiar 
 contrivances, any small error produced by accidental dust, 
 or by any slight inaccuracy in one of the wheels, is cor- 
 rected as soon as it is transmitted to the next, and this is 
 done in such a manner as effectually to prevent any ac- 
 cumulation of small errors from producing an erroneous 
 figure in the result. 
 
 In order to convey some idea of this stupendous under- 
 taking, we may mention the effects produced by a small 
 trial engine constructed by the inventor, and by which he 
 computed the following table from the formula # 2 -{- % -f- 41. 
 The figures as they were calculated by the machine were 
 not exhibited to the eye as in sliding rules and similar 
 instruments, but were actually presented to the eye on two 
 
344 LETTERS ON NATURAL MAGIC. 
 
 opposite sides of the machine ; the number 383, for example, 
 appearing in figures before the person employed in 
 copying. 
 
 Table calculated ly a small Trial Engine. 
 
 41 
 
 131 
 
 383 
 
 797 
 
 1373 
 
 43 
 
 151 
 
 421 
 
 853 
 
 1447 
 
 47 
 
 173 
 
 461 
 
 911 
 
 1523 
 
 53 
 
 197 
 
 583 
 
 971 
 
 1601 
 
 61 
 
 223 
 
 547 
 
 1033 
 
 1681 
 
 71 
 
 251 
 
 598 
 
 1097 
 
 1763 
 
 83 
 
 281 
 
 641 
 
 1163 
 
 1847 
 
 97 
 
 313 
 
 691 
 
 1231 
 
 1933 
 
 113 347 743 1301 2021 
 
 While the machine was occupied in calculating this table, 
 a friend of the inventor undertook to write down the 
 numbers as they appeared. In consequence of the copyist 
 writing quickly, he rather more than kept pace with the 
 engine, but as soon as five figures appeared, the machine 
 was at least equal in speed to the writer. At another 
 trial thirty-two numbers of the same table were calculated 
 in the space of two minutes and thirty seconds, and as these 
 contained eighty-two figures, the engine produced thirty- 
 three figures every minute, or more than one figure in 
 every two seconds. On another occasion it produced 
 forty-four figures per minute. This rate of computation 
 could be maintained for any length of time ; and it is 
 probable that few writers are able to copy with equal 
 speed for many hours together. ' 
 
 Some of that class of individuals who envy all great 
 men, and deny all great inventions, have ignorantly stated 
 that Mr. Babbage's invention is not new. The same 
 persons, had it suited their purpose, would have maintained 
 that the invention of spectacles was an anticipation of the 
 telescope ; but even this is more true than the allegation, 
 that the arithmetical machines of Pascal and others were 
 
MR. BABBAGE'S CALCULATING MACHINE. 345 
 
 the types of Mr. Babbage's engine. The object of these 
 machines was entirely different. Their highest functions 
 were to perform the operations of common arithmetic. 
 Mr. Babbage's engine, it is true, can perform these opera- 
 tions also, and can extract the roots of numbers, and 
 approximate to the roots of equations, and even to their 
 impossible roots. But this is not its object. Its 
 function, in contradistinction to that of all other contriv- 
 ances for calculating, is to embody in machinery the 
 method of differences, which has never before been done ; 
 and the effects which it is capable of producing, and the 
 works which in the course of a few years we expect to see 
 it execute, will place it at an infinite distance from all 
 other efforts of mechanical genius.* 
 
 * A popular account of this engine will be found in Mr. Babbage's 
 interesting volume On the Economy of Manufactures, 
 
 2 A 
 
346 LETTERS ON NATURAL MAGIC. 
 
 LETTER XII. 
 
 Wonders of chemistry Origin, progress, and objects of alchemy Art 
 of breathing fire Employed by Barchochebas, Eunus, &c. 
 Modern method Art of walking upon burning coals and red-hot 
 iron, and of plunging the hands in melted lead and boiling water 
 Singular property of boiling tar Workmen plunge their hands 
 in melted copper Trial of ordeal by fire Aldini's incombustible 
 dresses Examples of their ivonderful power in resisting flame 
 Power of breathing and enduring air of high temperatures 
 Experiments made by Sir Joseph Banks, Sir Charles Blagden, 
 and Mr. Chantry. 
 
 THE science of chemistry has from its infancy been pre- 
 eminently the science of wonders. In her laboratory the 
 alchemist and the magician have revelled uncontrolled, 
 and from her treasures was forged the sceptre which was 
 so long and so fatally wielded over human reason. The 
 changes which take place in the bodies immediately 
 around us are too few in number and too remote from ob- 
 servation to excite much of our notice ; but when the sub- 
 stances procured directly from nature, or formed casually 
 by art, become objects of investigation, they exhibit in 
 their simple or combined actions the most extraordinary 
 effects. The phenomena which they display, and the 
 products which they form, so little resemble those with 
 which we are familiar, that the most phlegmatic and the 
 least speculative observer must have anticipated from them 
 the creation of new and valuable compounds. It can 
 scarcely, therefore, be a matter of surprise that minds of 
 the highest order, and spirits of the loftiest ambition, 
 
ORIGIN OF ALCHEMY. 347 
 
 should have sought in the transmutations of chemistry 
 for those splendid products which were conceived to be 
 most conducive to human happiness. 
 
 The disciple of Mammon grew pale over his crucible in 
 his ardour to convert the baser metals into gold : the 
 philosopher pined in secret for the universal solvent 
 which might develop the elements of the precious stones, 
 and yield to him the means of their production ; and the 
 philanthropist aspired after a universal medicine, which 
 might arrest disease in its course, and prolong indefinitely 
 the life of man. To us who live under the meridian of 
 knowledge, such expectations must appear as presumptuous 
 as they were delusive ; but when we consider that gold 
 and silver were actually produced by chemical processes 
 from the rude ores of lead and copper j that some of the 
 most refractory bodies had yielded to the disintegrating 
 and solvent powers of chemical agents; and that the 
 mercurial preparations of the Arabian physicians had 
 operated like charms in the cure of diseases that had 
 resisted the feeble medicines of the times, we may find 
 some apology for the extravagant expectations of the 
 alchemists. 
 
 An object of lofty pursuit, even if it be one of impossible 
 attainment, is not unworthy of philosophical ambition. 
 Though we cannot scale the summit of the volcanic cone, 
 we may yet reach its heaving flanks, and though we can- 
 not decompose its loftiest fires, we may yet study the lava 
 which they have melted and the products which they have 
 sublimed. In like manner, though the philosopher's 
 stone has not been found, chemistry has derived rich 
 accessions from its search; though the general solvent 
 has not been obtained, yet the diamond and the gems 
 have surrendered to science their adamantine strength ; 
 and though the elixir of life has never been distilled, yet 
 other medicines have soothed u the ills which flesh is heir 
 
348 LETTERS ON NATURAL MAGIC. 
 
 to," and prolonged in no slight degree the average term 
 of our existence. 
 
 Thus far the pursuits of the alchemist were honourable 
 and useful; but when his calling was followed, as it 
 soon was, by men prodigal of fortune and of character, 
 science became an instrument of crime ; secrets unattained 
 were bartered for the gold of the credulous and the igno- 
 rant, and books innumerable were composed to teach these 
 pretended secrets to the world. An intellectual reaction, 
 however, soon took place, and those very princes who had 
 sought to fill their exhausted treasuries at the furnace of 
 the chemist, were the first to enact laws against the frauds 
 which they had encouraged, and to dispel the illusions 
 which had so long deceived their subjects. 
 
 But even when the moral atmosphere of Europe was 
 thus disinfected, chemistry supplied the magician with his 
 most lucrative wonders, and those who could no longer 
 delude the public with dreams of wealth and longevity, 
 now sought to amuse and astonish them by the exhibition 
 of their skill. The narrow limits of this volume will not 
 permit me to give even a general view of those extra- 
 ordinary effects which this popular science can display. 
 I must therefore select from its inexhaustible stores those 
 topics which are most striking in their results, and most 
 popular in their details. 
 
 One of the most ancient feats of magic was the art of 
 breathing flame an art which even now excites the asto- 
 nishment of the vulgar. During the insurrection of the 
 slaves in Sicily in the second century before Christ, a 
 Syrian named Eunus acquired by his knowledge the rank 
 of their leader. In order to establish his influence over 
 their minds, he pretended to possess miraculous power. 
 When he wished to inspire his followers with courage, he 
 breathed flames or sparks among them from his mouth, at 
 the same time that he was rousing them by his eloquence. 
 
WALKING ON BURNING COALS, ETC. 349 
 
 St. Jerome informs us, that the Kabbi Barchochebas, who 
 headed the Jews in their last revolt against Hadrian, made 
 them believe that he was the Messiah, by vomiting names 
 from his mouth ; and at a later period, the Emperor Con- 
 stantius was thrown into a state of alarm when Valentinian 
 informed him that he had seen one of the body guards 
 breathing out fire and flames. We are not acquainted 
 with the exact methods by which these effects were pro- 
 duced ; but Florus informs us, that Eunus filled a per- 
 forated nut-shell with sulphur and fire, and having con- 
 cealed it in his mouth, he breathed gently through it 
 while he was speaking. This art is performed more 
 simply by the modern juggler. Having rolled together 
 some flax or hemp, so as to form a ball the size of a 
 walnut, he sets it on fire, and allows it to burn till it is 
 nearly consumed : he then rolls round it while burning 
 some additional flax, and by these means the fire may be 
 retained in it for a considerable time. At the commence- 
 ment of his exhibition he introduces the ball into his 
 mouth, and while he breathes through it the fire is revived, 
 and a number of burning sparks are projected from his 
 mouth. These sparks are too feeble to do any harm, pro- 
 vided he inhales the air through his nostrils. 
 
 The kindred art of walking on burning coals or red- 
 hot iron belongs to the same antiquity. The priestesses 
 of Diana at Castabala in Cappadocia were accustomed, 
 according to Strabo, to walk over burning coals ; and at 
 the annual festival, which was held in the temple of 
 Apollo on Mount Soracte in Etruria, the Hirpi marched 
 over burning coals, and on this account they were exempted 
 from military service, and received other privileges from 
 the Koman Senate. This power of resisting fire was 
 ascribed even by Varro to the use of some liniment with 
 which they anointed the soles of their feet. 
 
 Of the same character was the art of holding red-hot 
 
350 LETTERS ON NATURAL MAGIC. 
 
 iron in the hands or between the teeth, and of plunging 
 the hands into boiling water or melted lead. About the 
 close of the seventeenth century, an Englishman of the 
 name of Richardson rendered himself famous by chewing 
 burning coals, pouring melted lead upon his tongue, and 
 swallowing melted glass. That these effects are produced 
 partly by deception, and partly by a previous preparation 
 of the parts subjected to the heat, can scarcely admit of a 
 doubt. The fusible metal, composed of mercury, tin, and 
 bismuth, which melts at a low temperature, might easily 
 have been substituted in place of lead ; and fluids of easy 
 ebullition may have been used in place of boiling water. 
 A solution of spermaceti or sulphuric ether, tinged with 
 alkanet root, which becomes solid at 50 of Fahrenheit, 
 and melts and boils with the heat of the hand, is supposed 
 to be the substance which is used at Naples when the 
 dried blood of St. Januarius melts spontaneously, and 
 boils over the vessel which contains it. 
 
 But even when the fluid requires a high temperature to 
 boil, it may have other properties, which enable us to 
 plunge our hands into it with impunity. This is the case 
 with boiling tar, which boils at a temperature of 220, 
 even higher than that of water. Mr. Davenport informs 
 us, that he saw one of the workmen in the King's Dock- 
 yard at Chatham immerse his naked hand in tar of that 
 temperature. He drew up his coat sleeves, dipped in his 
 hand and wrist, bringing out fluid tar, and pouring it off 
 from his hand as from a ladle. The tar remained in com- 
 plete contact with his skin, and he wiped it off with tow. 
 Convinced that there was no deception in this experiment, 
 Mr. Davenport immersed the entire length of his fore- 
 finger in the boiling cauldron, and moved it about a short 
 time before the heat became inconvenient. Mr. Daven- 
 port ascribes this singular effect to the slowness with 
 which the tar communicates its heat, which he conceives 
 
HANDS PLUNGED IN MELTED COPPER. 351 
 
 to arise from the abundant volatile vapour which is 
 evolved " carrying off rapidly the caloric in a latent state, 
 and intervening between the tar and the skin, so as to 
 prevent the more rapid communication of heat." He con- 
 ceives also, that when the hand is withdrawn, and the hot 
 tar adhering to it, the rapidity with which this vapour is 
 evolved from the surface exposed to the air cools it im- 
 mediately. The workmen informed Mr. Davenport, that, 
 if a person put his hand into the cauldron with his glove 
 on, he would be dreadfully burnt, but this extraordinary 
 result was not put to the test of observation. 
 
 But though the conjurers with fire may have availed 
 themselves of these singular properties of individual 
 bodies, yet the general secret of their art consisted in 
 rendering the skin of the exposed parts callous and in- 
 sensible to heat an effect which may be produced by 
 continually compressing or singeing them till the skin 
 acquires a horny consistence. A proof of this opinion is 
 mentioned by Beckmann, who assures us that in September, 
 1765, when he visited the copper-works at Awestad, one 
 of the workmen, bribed by a little money to drink, took 
 some of the melted copper in his hand, and after showing 
 it to the company, threw it against a wall. He then 
 squeezed the fingers of his horny hand close to each other, 
 held it a few minutes under his arm-pit to make it perspire, 
 as he said, and taking it again out, drew it over a ladle 
 filled with melted copper, some of which he skimmed off 
 and moved his hand backwards and forwards very quickly 
 by way of ostentation. During this performance M. 
 Beckmann noticed a smell like that of singed horn or 
 leather, though the hand of the workman was not burned. 
 This callosity of the skin may be effected by frequently 
 moistening it with dilute sulphuric acid. Some allege 
 that the juices of certain plants produce the same effect, 
 while others recommend the frequent rubbing of the skin 
 
352 LETTERS ON NATURAL MAGIC. 
 
 with oil. The receipt given by Albertus Magnus for this 
 purpose was of a different nature. It consisted of a non- 
 conducting calcareous paste, which was made to adhere to 
 the skin by the sap of the marsh-mallow, the slimy seeds 
 of the flea-bane, and the white of an egg. 
 
 As the ancients were acquainted with the incombus- 
 tibility of asbestos or amianthus, and the art of weaving 
 it into cloth, it is highly probable that it was employed 
 in the performance of some of their miracles, and it is 
 equally probable that it was subsequently used, along 
 with some of the processes already described, in enabling 
 the victims of superstition to undergo without hazard the 
 trial of ordeal by fire. In every country where this bar- 
 barous usage prevailed, whether in the sanctuary of the 
 Christian idolater, or in the pagan temple of the Bramin, 
 or under the wild orgies of the African savage, Providence 
 seems to have provided the means of meeting it with im- 
 punity. In Catholic countries this exculpatory judgment 
 was granted chiefly to persons in weak health, who were 
 incapable of using arms, and particularly to monks and 
 ecclesiastics who could not avail themselves of the trial 
 by single combat. The fire ordeal was conducted in the 
 church under the inspection of the clergy : mass was at 
 the same time celebrated, and the iron and the victim^ 
 were consecrated by the sprinkling of holy water. The 
 preparatory steps were also under the direction of the 
 priests. It was necessary that the accused should be 
 placed three days and three nights under their care, both 
 before and after the trial. Under the pretence of prevent- 
 ing the defendant from preparing his hands by art, and 
 in order to ascertain the result of the ordeal, his hands 
 were covered up and sealed during the three days which 
 preceded and followed the fiery application ; and it has 
 been plausibly conjectured by Beckmann, that during the 
 first three days the preventative was applied to those 
 
ALDINI S INCOMBUSTIBLE DRESSES. 
 
 353 
 
 whom they wished to acquit, and that the last three days 
 were requisite to bring back the hands to their natural 
 condition. In these and other cases, the accused could 
 not have availed himself directly of the use of asbestos 
 gloves, unless we could suppose them so made as to 
 imitate the human skin at a distance ; but the fibres of 
 that mineral may have been imbedded in a paste which 
 applied itself readily to all the elevations and depressions 
 of the skin. 
 
 In our own times the art of defending the hands and 
 face, and indeed the whole body, from the action of 
 heated iron and intense fire, has been applied to the 
 nobler purpose of saving human life, and rescuing pro- 
 perty from the flames. The revival and the improvement 
 of this art we owe to the benevolence and the ingenuity of 
 the Chevalier Aldini of Milan, who has travelled through 
 all Europe to present this valuable gift to his species. 
 Sir H. Davy had long ago shown that a safety lamp for 
 illuminating mines, containing inflammable air, might be 
 constructed of wire-gauze alone, which prevented the 
 flame within, however large or intense, from setting fire to 
 the inflammable air without. This valuable property, 
 which has been long in practical use, he ascribed to the 
 conducting and radiating power of the wire-gauze, which 
 carried off the heat of the flame, and deprived it of its 
 power. The Chevalier Aldini conceived the idea of apply- 
 ing the same material in combination with other badly- 
 conducting substances, as a protection against fire. The 
 incombustible pieces of dress which he uses for the body, 
 arms, and legs, are formed out of strong cloth, which has 
 been steeped in a solution of alum, while those for the 
 head, hands, and feet, are made of cloth of asbestos or 
 amianthus. The head-dress is a large cap which enve- 
 lops the whole head down to the neck, having suitable 
 perforations for the eyes, nose, and mouth. The stockings 
 
354 LETTERS ON NATURAL MAGIC. 
 
 and cap are single, but the gloves are made of double 
 amianthus cloth, to enable the fireman to take into his 
 hand burning or red-hot bodies. The piece of ancient 
 asbestos cloth preserved in the Vatican was. formed, we 
 believe, by mixing the asbestos with other fibrous sub- 
 stances ; but M. Aldini has executed a piece of nearly the 
 same size, nine feet five inches long, and five feet three 
 inches wide, which is much stronger than the ancient 
 piece, and possesses superior qualities, in consequence of 
 having been woven without the introduction of any 
 foreign substance. In this manufacture the fibres are 
 prevented from breaking by the action of steam, the cloth 
 is made loose in its fabric, and the threads are about the 
 fiftieth of an inch in diameter. 
 
 The metallic dress which is superadded to these means 
 of defence consists of five principal pieces, viz., a casque or 
 cap, with a mask large enough to leave a proper space 
 between it and the asbestos cap ; a cuirass with its brass- 
 ets ; a piece of armour for the trunk and thighs ; a pair of 
 boots of double wire-gauze ; and an oval shield five feet 
 long by 2 wide, made by stretching the wire-gauze over 
 a slender frame of iron. All these pieces are made of 
 iron wire-gauze, having the interval between its threads 
 the twenty-fifth part of an inch. 
 
 In order to prove the efficacy of this apparatus, and 
 inspire the firemen with confidence in its protection, he 
 showed them that a finger first enveloped in asbestos, and 
 then in a double case of wire-gauze, might be held a long 
 time in the flame of a spirit-lamp or candle before the 
 heat became inconvenient. A fireman having his hand 
 within a double asbestos glove, and its palm protected by 
 a piece of asbestos cloth, seized with impunity a large 
 piece of red-hot iron, carried it deliberately to the distance 
 of 150 feet, inflamed straw with it, and brought it back 
 again to the furnace. On other occasions, the firemen 
 
ALDINl's INCOMBUSTIBLE DRESSES. 
 
 355 
 
 handled blazing wood and burning substances, and walked 
 during five minutes upon an iron grating placed over 
 flaming faggots. 
 
 In order to show how the head, eyes, and lungs, are 
 protected, the fireman put on the asbestos and wire-gauze 
 cap, and the cuirass, and held the shield before his breast. 
 A fire of shavings was then lighted, and kept burning in a 
 large raised chafing-dish, and the fireman plunged his 
 head into the middle of the flames with his face to the 
 fuel, and in that position went several times round the 
 
 Fig. 72. 
 
 chafing-dish for a period longer than a minute. In a 
 subsequent trial at Paris, a fireman placed his head in the 
 middle of a large brasier filled with flaming hay and 
 wood, as in Fig. 72, and resisted the action of the fire 
 during five or six minutes, and even ten minutes. 
 
 In the experiments which were made at Paris in the 
 presence of a committee of the Academy of Sciences, two 
 
356 LETTERS ON NATUBAL MAGIC. 
 
 parallel rows of straw and brushwood, supported by iron 
 wires, were formed at the distance of three feet from 
 each other, and extended thirty feet in length. When 
 this combustible mass was set on fire, it was necessary to 
 stand at the distance of eight or ten yards to avoid the 
 heat. The flames from both the rows seemed to fill up 
 the whole space between them, and rose to the height of 
 nine or ten feet. At this moment six firemen, clothed in 
 the incombustible dresses, and marching at a slow pace 
 behind each other, repeatedly passed through the whole 
 length between the two rows of flame, which were con- 
 stantly fed with additional combustibles. One of the 
 firemen carried on his back a child eight years old 
 in a wicker basket covered with metallic gauze, and the 
 child had no other dress than a cap made of amianthine 
 cloth. 
 
 In February, 1829, a still more striking experiment was 
 made in the yard of the barracks of St. Gervais. Two 
 towers were erected two stories high, and were surrounded 
 with heaps of inflamed materials, consisting of faggots and 
 straw. The firemen braved the danger with impunity. In 
 opposition to the advice of M. Aldini, one of them, with 
 the basket and child, rushed into a narrow place, where 
 the flames were raging eight yards high. The violence of 
 the fire was so great that he could not be seen, while a 
 thick black smoke spread around, throwing out a heat 
 which was unsupportable by the spectators. The fireman 
 remained so long invisible that serious doubts were 
 entertained of his safety. He at length, however, issued 
 from the fiery gulf uninjured, and proud of having suc- 
 ceeded in braving so great a danger. 
 
 It is a remarkable result of these experiments, that the 
 firemen are able to breathe without difficulty in the 
 middle of the flames. This effect is owing not only to 
 the heat being intercepted by the wire gauze as it passes 
 
SIR c. BLAGDEN'S EXPERIMENTS. 357 
 
 to the lungs, in consequence of which its temperature 
 becomes supportable, but also to the singular power 
 which the body possesses of resisting great heats, and of 
 breathing air of high temperatures. 
 
 A series of curious experiments were made on this sub- 
 ject by M. Tillet, in France, and by Dr. Fordyce and Sir 
 Charles Blagden, in England. Sir Joseph Banks, Dr. 
 Solander, and Sir Charles Blagden, entered a room in 
 which the air had a temperature of 198 Fahr. and re- 
 mained ten minutes ; but as the thermometer sunk very 
 rapidly, they resolved to enter the room singly. Dr. 
 Solander went in alone, and found the heat 210. and Sir 
 Joseph entered when the heat was 211. Though exposed 
 to such an elevated temperature, their bodies preserved 
 their natural degree of heat. Whenever they breathed 
 upon a thermometer it sunk several degrees : every 
 expiration, particularly if strongly made, gave a pleasant 
 impression of coolness to their nostrils, and their cold 
 breath cooled their fingers whenever it reached them. On 
 touching his side, Sir Charles Blagden found it cold like 
 a corpse, and yet the heat of his body under his tongue 
 was 98. Hence they concluded that the human body 
 possesses the power of destroying a certain degree of 
 heat when communicated with a certain degree of 
 quickness. This power, however, varies greatly in differ- 
 ent media. The same person who experienced no incon- 
 venience from air heated to 211, could just bear rectified 
 spirits of wine at 130, cooling oil at 129, cooling water 
 at 123, and cooling quicksilver at 117. A familial- 
 instance of this occurred in the heated room. All the 
 pieces of metal there, even their watch-chains, felt so hot, 
 that they could scarcely bear to touch them for a moment, 
 while the air from which the metal had derived all its 
 heat was only unpleasant. MM. Duhamel and Tillet 
 observed at Rochefoucault in France, that the girls who were 
 
358 LETTERS ON NATURAL MAGIC. 
 
 accustomed to attend ovens in a bakehouse were capable 
 of enduring for ten minutes a temperature of 270. 
 
 The same gentlemen who performed the experiments 
 above described ventured to expose themselves to still 
 higher temperatures. Sir Charles Blagden went into a 
 room where the heat was 1 or 2 3 above 260, and re- 
 mained eight minutes in this situation, frequently walking 
 about to all the different parts of the room, but standing 
 still most of the time in the coolest spot, where the heat 
 was above 240. The air, though very hot, gave no pain, 
 and Sir Charles and all the other gentlemen were of 
 opinion that they could support a much greater heat. 
 During seven minutes, Sir C. Blagden 's breathing con- 
 tinued perfectly good, but after that time he felt an 
 oppression in his lungs, with a sense of anxiety, which 
 induced him to leave the room. His pulse was then 144, 
 double its ordinary quickness. In order to prove that 
 there was no mistake respecting the degree of heat indi- 
 cated by the thermometer, and that the air which they 
 breathed was capable of producing all the well-known 
 effects of such a heat on inanimate matter, they placed 
 some eggs and a beef-steak upon a tin frame near the 
 thermometer, but more distant from the furnace than from 
 the wall of the room. In the space of twenty minutes 
 the eggs were roasted quite hard, and in forty -seven 
 minutes the steak was not only dressed, but almost dry. 
 Another beef-steak, similarly placed, was rather overdone 
 in thirty-three minutes. In the evening, when the heat 
 was still more elevated, a third beef-steak was laid in the 
 same place, and as they had noticed that the effect of the 
 hot air was greatly increased by putting it in motion, they 
 blew upon the steak with a pair of bellows, and thus 
 hastened the dressing of it to such a degree, that the 
 greatest portion of it was found to be pretty well done in 
 thirteen minutes. 
 
MR. CHANTEY'S EXPERIMENTS. 359 
 
 Our distinguished countryman, Mr. Chantry, has very 
 recently exposed himself to a temperature still higher 
 than any which we have mentioned. The furnace which 
 he employs for drying his moulds is about 14 feet long, 
 12 feet high, and 12 feet broad. When it is raised to its 
 highest temperature, with the doors closed, the thermo- 
 meter stands at 350, and the iron floor is red hot. The 
 workmen often enter it at a temperature of 340, walking 
 over the iron floor with wooden clogs, which are of course 
 charred on the surface. On one occasion Mr. Chantry, 
 accompanied by five or six of his friends, entered the 
 furnace, and, after remaining two minutes, they brought 
 out a thermometer which stood at 320. Some of the 
 party experienced sharp pains in the tips of their ears, 
 and in the septum of the nose, while others felt a pain 
 in their eyes. 
 
360 LETTERS ON NATURAL MAGIC. 
 
 LETTER XIII. 
 
 Spontaneous combustion In the absorption of air by powdered 
 charcoal, and of hydrogen by spongy platinum Dobereiner's 
 lamp Spontaneous combustion in the bowels of the earth 
 Burning cliffs Burning soil Combustion without flame Spon- 
 taneous combustion of human beings Countess Zangari Grace 
 Pett Natural fire temples of the Guebres Spontaneous fires in 
 the Caspian Sea Springs of inflammable gas near Glasgow 
 Natural light-house of Maracaybo New elastic fluids in the 
 cavities of gems Chemical operation going on in their cavities 
 Explosions produced in them by heat Eemarkdble changes of 
 colour from chemical causes Effects of the nitrous oxide or 
 paradise gas when breathed Itemarkable cases described 
 Conclusion. 
 
 AMONG the wonderful phenomena which chemistry pre- 
 sents to us, there are few more remarkable than those of 
 spontaneous combustion, in which bodies, both animate 
 and inanimate, emit flames, and are sometimes entirely 
 consumed by internal fire. One of the commonest experi- 
 ments in chemistry is that of producing inflammation by 
 mixing two fluids perfectly cold. Becker, we believe, was 
 the first person who discovered that this singular effect 
 was produced by mixing oil of vitrol with oil of turpen- 
 tine. Borrichios showed that aquafortis produced the 
 same effect as oil of vitrol. Tournefort proved that spirit 
 of nitre and oil of sassafras took fire when mixed ; and 
 Homberg discovered that the same property was possessed 
 by many volatile oils when mixed with spirit of nitre. 
 
 Every person is familiar with the phenomena of heat 
 and combustion produced by fermentation. Ricks of hay 
 
SPONTANEOUS COMBUSTION. 361 
 
 and stacks of corn have been frequently consumed by the 
 heat generated during the fermentation produced from 
 moisture; and gunpowder magazines, barns, and paper- 
 mills have been often burnt by the fermentation of the 
 materials which they contained. Galen informs us that 
 the dung of a pigeon is sufficient to set fire to a house, 
 and he assures us that he has often seen it take fire when 
 it had become rotten. Casati likewise relates on good 
 authority, that the fire which consumed the great church 
 of Pisa was ^occasioned by the dung of pigeons that had 
 for centuries built their nests under its roof. 
 
 Among the substances subject to spontaneous combus- 
 tion, pulverized or finely-powdered charcoal is one of the 
 most remarkable. During the last thirty years no fewer 
 than four cases of the spontaneous inflammation of pow- 
 dered charcoal have taken place in France. When char- . 
 coal is triturated in tuns with bronze bruisers it is reduced 
 into the state of the finest powder. In this condition it 
 has the appearance of an unctuous fluid, and it occupies a 
 space three times less than it does in rods of about six 
 inches long. In this state of extreme division it absorbs 
 air much more readily than it does when in rods. This 
 absorption, which is so slow as to require several days for 
 its completion, is accompanied with a disengagement of 
 heat, which rises from 340 to 360 nearly of Fahrenheit, 
 and which is the true cause of the spontaneous inflam- 
 mation. The inflammation commences near the centre of 
 the mass, at the depth of five or six inches beneath its 
 surface, and at this spot the temperature is always higher 
 than at any other. Black charcoal strongly distilled 
 heats and inflames more easily than the orange, or that 
 which is little distilled, or than the charcoal made in 
 boilers. The most inflammable charcoal must have a 
 mass of at least 66 Ibs. avoirdupois, in order that it may 
 be susceptible of spontaneous inflammation. With the 
 
 2 B 
 
362 LETTERS ON NATURAL MAGIC. 
 
 other less inflammable varieties, the inflammation takes 
 place only in larger masses. 
 
 T.he inflammation of powdered charcoal is more active 
 in proportion to the shortness of the interval between its 
 carbonization and trituration. The free admission of air 
 to the surface of the charcoal is also indispensable to its 
 spontaneous combustion. 
 
 Colonel Aubert, to whom we owe these interesting 
 results, likewise found that when sulphur and saltpetre 
 are added to the charcoal, it loses its power of inflaming 
 spontaneously. But as there is still an absorption of 
 air and a generation of heat, he is of opinion that it would 
 not be prudent to leave these mixtures in too large masses 
 after trituration.* 
 
 A species of spontaneous combustion, perfectly analo- 
 gous to that now described, but produced almost instan- 
 taneously, was discovered by Professor Dobereiner of 
 Jena in 1824. He found that when a jet of hydrogen gas 
 was thrown upon recently-prepared spongy platinum, the 
 metal became almost instantly red hot, and set fire to the 
 gas. In this case the minutely-divided platinum acted 
 upon the hydrogen gas, in the same manner as the minutely- 
 divided charcoal acted upon common air. Heat and com- 
 bustion were produced by the absorption of both gases, 
 though in the one case the effect was instantaneous, and in 
 the other was the result of a prolonged absorption. 
 
 This beautiful property of spongy platinum was happily 
 applied to the construction of lamps for producing an 
 instantaneous light. The form given to the lamp by 
 Mr. Garden of London is shown in the annexed figure, 
 where A B is a globe of glass, fitting tightly into another 
 glass globe C D by a ground shoulder m n. The globe 
 A B terminates in a hollow tapering neck m n o p, on the 
 
 * See Edinburgh Journal of Science, New Series, No. viii. p. 274. 
 
SPONTANEOUS COMBUSTION. 
 
 363 
 
 lower end of which is placed a small cylinder of zinc o p. 
 A brass tube a b c is fitted at a into the neck of the globe 
 C D, and through this tube, which is furnished with a 
 stop-cock d, the gas can escape at the small aperture c. 
 A brass pin c /, carrying a brass box P, is made to slide 
 through a hole h, so that the brass box P, in which the 
 spongy platinum is placed, can be set at any required 
 distance from the aperture c. If sulphuric acid diluted 
 
 Fig. 73. 
 
 with an equal quantity of water is now poured into the 
 vessel A B by its mouth at S, now closed with a stopper, 
 the fluid will descend through the tube m n o p, and if the 
 cock d is shut, it will compress the air contained in C D. 
 The dilute acid thus introduced into C D will act upon 
 the ring of zinc o p, and generate hydrogen gas, which 
 after the atmospheric air in C D is let off, will gradually 
 fill the vessel C D, the diluted acid being forced up the 
 tube o p m n, into the glass globe A B. The ring of zinc 
 o p floats on a piece of cork, so that when C D is full of 
 
364 LETTERS ON NATURAL MAGIC. 
 
 hydrogen, the diluted acid does not touch the zinc, and 
 consequently is prevented from producing any more gas. 
 The instant, however, that any gas is let off at c, the pres- 
 sure of the fluid in the globe A B, and tube m, n o p, over- 
 comes the elasticity of the remaining gas in C D, and 
 forces the diluted acid up to the zinc o p, so as to enable 
 it to produce more gas to supply what has been used. 
 
 The lamp being supplied with hydrogen in the manner 
 now described, it is used in the following manner : The 
 spongy platinum in P being brought near c, the cock d 
 is turned, and the gas is thrown upon the platinum. An 
 intense heat is immediately produced, the platinum be- 
 comes red hot, and the hydrogen inflames. A taper is 
 then lighted at the flame, and the cock d is shut. Pro- 
 fessor Gumming of Cambridge found it necessary to cover 
 up the platinum with a cap after every experiment. This 
 ingenious chemist likewise found that, with platinum 
 foil the 9000dth part of an inch thick kept in a close tube, 
 the hydrogen was inflamed ; but when the foil was only the 
 GOOOdth of an inch thick, it was necessary to raise it 
 previously to a red heat. 
 
 Spontaneous combustion is a phenomenon which occurs 
 very frequently, and often to a great extent, within the 
 bowels of the earth. The heat by which it is occasioned 
 is ^produced by the decomposition of mineral bodies, and 
 other causes. This heat increases in intensity till it is 
 capable of melting the solid materials which are exposed 
 to it. Gases and aqueous vapours of powerful elasticity 
 are genrated, new fluids of expansive energy imprisoned 
 in cavities under great pressure are set free, and these 
 tremendous agents, acting under the repressing forces of 
 the superincumbent strata, exhibit their power in desolat- 
 ing earthquakes ; or, forcing their way through the super- 
 ficial crust of the globe, they waste their fury in volcanic 
 eruptions. 
 
COMBUSTION WITHOUT FLAME. 365 
 
 When the phenomena of spontaneous combustion take 
 place near the surface of the earth, its effects are of a less 
 dangerous character, though they frequently give birth to 
 permanent conflagrations, which no power can extinguish. 
 An example of this milder species of spontaneous combus- 
 tion has been recently exhibited in the burning cliff at 
 Weymouth ; and a still more interesting one exists at this 
 moment near the village of Bradley, in Staffordshire. 
 The earth is here on fire, and this fire has continued for 
 nearly sixty years, and has resisted every attempt that has 
 been made to extinguish it. This fire, which has reduced 
 many acres of land to a mere calx, arises from a burning 
 stratum of coal about four feet thick and eight or ten 
 yards deep, to which the air has free access, in conse- 
 quence of the main coal having been dug from beneath it. 
 The surface of the ground is sometimes covered for many 
 yards with such quantities of sulphur that it can be easily 
 gathered. The calx has been found to be an excellent 
 material for the roads, and the workmen who collect it 
 often find large beds of alum of an excellent quality. 
 
 A singular species of invisible combustion, or of com- 
 bustion without flame, has been frequently noticed. I 
 have observed this phenomenon in the small green wax 
 tapers in common use. When the flame is blown out, the 
 wick will continue red hot for many hours, and if the 
 taper were regularly and carefully uncoiled, and the room 
 kept free from currents of air, the wick would burn on in 
 this way till the whole of the taper was consumed. The 
 same effects are not produced when the colour of the wax 
 is red. In this experiment the wick, after the flame is 
 blown out, has sufficient heat to convert the wax into 
 vapour, and this vapour, being consumed without flame, 
 keeps the wick at its red heat. A very disagreeable 
 vapour is produced during this imperfect combustion of 
 the wax. 
 
366 LETTERS ON NATURAL MAGIC. 
 
 Professor Dobereiner of Jena observed, that when the 
 alcohol in a spirit of wine lamp was nearly exhausted, the 
 wick became carbonized, and though the flame disappeared, 
 the carbonized part of the wick became red hot, and con- 
 tinued so while a drop of alcohol remained, and provided 
 the air in the room was undisturbed. On one occasion 
 the wick continued red hot for twenty-four hours, and a 
 very disagreeable acid vapour was formed. 
 
 On these principles depend the lamp without flame 
 which was originally constructed by Mr. Ellis. It is 
 shown in the annexed figure, where A B is the lamp, and 
 A a cylindrical coil of platinum wire, the hundredth part 
 
 Fig. 74. 
 
 of an inch in diameter. This spiral is so placed that four 
 or five of the twelve, coils of which the cylinder consists 
 arc upon the wick, and the other seven or eight above it. 
 If the lamp is lighted, and continues burning till the 
 cylindrical coil is red hot, then if the flame is blown out, 
 the vapour which arises from the alcohol will by its com- 
 bustion keep the coils above the wick red hot, and this 
 red heat will in its turn keep up the vaporisation of the 
 alcohol till the whole of the alcohol is consumed. The 
 heat of the wire is always sufficient to kindle a piece of 
 German fungus or saltpetre paper, so that a sulphur match 
 may at any time be lighted. Mr. Gill found that a wick 
 composed of twelve threads of the cotton yarn commonly 
 
SPONTANEOUS COMBUSTION. 367 
 
 used for lamps will require half an ounce of alcohol to 
 keep the wire red hot for eight hours. This lamp has 
 been kept burning for sixty hours ; but it can scarcely be 
 recommended for a bed-room, as an acid vapour is disen- 
 gaged during the burning of the alcohol. When perfumes 
 are dissolved in the alcohol, they are diffused through the 
 apartment during the slow combustion of the vapour. 
 
 A species of combustion without flame, and analogous 
 to that which has been described, is exhibited in the 
 extraordinary phenomena of the spontaneous combustion 
 of living bodies. That animal bodies are liable to 
 internal combustion is a fact which was well known to the 
 ancients. Many cases which have been adduced as ex- 
 amples of spontaneous combustion are merely cases of 
 individuals who were highly susceptible of strong electrical 
 excitation. In one of these cases, however, Peter Bovisteau 
 asserts, that the sparks of fire thus produced reduced to 
 ashes the hair of a young man ; and John De Viana 
 informs us, that the wife of Dr. Freilas, physician to the 
 Cardinal de Royas, Archbishop of Toledo, emitted by 
 perspiration an inflammable matter of such a nature, that 
 when the ribbon which she wore over her shift was taken 
 from her and exposed to the cold air, it instantly took fire, 
 and shot forth like grains of gunpowder. Peter Borelli 
 has recorded a fact of the very same kind respecting a 
 peasant whose linen took fire, whether it was laid up in a 
 box when wet, or hung up in the open air. The same 
 author speaks of a woman who, when at the point of 
 death, vomited flames; and Thomas Bartholin mentions 
 this phenomenon as having often happened to persons 
 who were great drinkers of wine or brandy. Ezekiel de 
 Castro mentions the singular case of Alexandrinus Mege- 
 tius, a physician, from one of whose vertebrae there issued 
 a fire which scorched the eyes of the beholders; and 
 Krantzius relates, that during the wars of Godfrey of 
 
368 LETTERS ON NATURAL MAGIC. 
 
 Boulogne, certain people of the territory of Nivers were 
 burning with invisible fire, and that some of them cut off' 
 a foot or a hand where the burning began, in order to 
 arrest the calamity. Nor have these effects been confined 
 to man. In the time of the Roman consuls Gracchus and 
 Juventius, a flame is said to have issued from the mouth 
 of a bull without doing any injury to the animal. 
 
 The reader will judge of the decree of credit which 
 may belong to these narrations when he examines the 
 effects of a similar kind which have taken place in less 
 fabulous ages, and nearer our own times. John Henry 
 Cohausen informs us, that a Polish gentleman in the time 
 of the Queen Bona Sforza, having drunk two dishes of a 
 liquor called brandy- wine, vomited flames, and was burned 
 by them, and Thomas Bartholin* thus describes a similar 
 accident : " A poor woman at Paris used to drink spirit 
 of wine plentifully for the space of three years, so as to 
 take nothing else. Her body contracted such a com- 
 bustible disposition, that one night, when she lay down 
 on a straw couch, she was all burned to ashes except her 
 skull and the extremities of her fingers." John Christ 
 Sturmius informs us in the German Ephemerides, that in 
 the northern countries of Europe flames often evaporate 
 from the stomachs of those who are addicted to the 
 drinking of strong liquors ; and he adds, " that seventeen 
 years before, three noblemen of Corn-land drank by 
 emulation strong liquors, and two of them died scorched 
 and suffocated by a flame which issued from their 
 stomach." 
 
 One of the most remarkable cases of spontaneous 
 combustion is that of the Countess Cornelia Zangari and 
 Bandi of Cesena, which has been minutely described by 
 the Reverend Joseph Bianchini, a prebend in the city of 
 
 * Acta Medico, et Philosophica Hafniensia, 1673. 
 
CASE OF COUNTESS ZANGARI. 369 
 
 Verona. This lady, who was in the sixty-second year of 
 her age, retired to bed in her usual health. Here she 
 spent above three hours in familiar conversation with her 
 maid and in saying her prayers ; and having at last fallen 
 asleep, the door of her chamber was shut. As her maid 
 was not summoned at the usual hour, she went into the 
 bed-room to wake her mistress ; but receiving no answer 
 she opened the window, and saw her corpse on the floor 
 in the most dreadful condition. At the distance of four 
 feet from the bed there was a heap of ashes. Her legs, 
 with the stockings on, remained untouched, and the head, 
 half -burned, lay between them. Nearly all the rest of 
 the body was reduced to ashes. The air in the room was 
 charged with floating soot. A small oil lamp on the floor 
 was covered with ashes, but had no oil in it ; and in two 
 candlesticks, which stood upright upon a table, the cotton 
 wick of both the candles was left, and the tallow of both 
 had disappeared. The bed was not injured, and the 
 blankets and sheets were raised on one side as if a 
 person had risen up from it. From an examination of all 
 the circumstances of this case, it has been generally 
 supposed that an internal combustion had taken place; 
 that the lady had risen from her bed to cool herself, and 
 that, in her way to open the window, the combustion had 
 overpowered her, and consumed her body by a process in 
 which no flame was produced which could set fire to the 
 furniture or the floor. The Marquis Scipio Maffei was 
 informed by an Italian nobleman who passed through 
 Cesena a few days after this event, that he heard it stated 
 in that town, that the Countess Zangari was in the habit, 
 when she felt herself indisposed, of washing all her body 
 with camphorated spirit of wine. 
 
 So recently as 1744 a similar example of spontaneous 
 combustion occurred in our own country at Ipswich. A 
 fisherman's wife of the name of Grace Pett, of the parish 
 
370 LETTERS ON NATURAL MAGIC. 
 
 of St. Clements, had been in the habit for several years of 
 going down stairs every night after she was half-undressed 
 to smoke a pipe. She did this on the evening of the 9th 
 of April, 1744. Her daughter, who lay in the same bed 
 with her, had fallen asleep, and did not miss her mother 
 till she awaked early in the morning. Upon dressing 
 herself, and going down stairs, she found her mother's 
 body lying on the right side with her head against the 
 grate, and extended over the hearth with her legs on the 
 deal floor, and appearing like a block of wood burning 
 with a glowing fire without flame. Upon quenching the 
 fire with two bowls of water, the neighbours, whom the 
 cries of the daughter had brought in, were almost stifled 
 with the smell. The trunk of the unfortunate woman 
 was almost burned to ashes, and appeared like a heap of 
 charcoal covered with white ashes. The head, arms, legs, 
 and thighs, were also much burned. There was no fire 
 whatever in the grate, and the candle was burned out in 
 the socket of the candlestick, which stood by her. The 
 clothes of a child on one side of her, and a paper screen 
 on the other, were untouched; and the deal floor was 
 neither singed nor discoloured. It was said that the woman 
 had drunk plentifully of gin overnight in welcoming a 
 daughter who had recently returned from Gibraltar. 
 
 Among the phenomena of the natural world which are 
 related to those of spontaneous combustion, are what have 
 been called the natural fire temples of the Guebres, and 
 the igneous phenomena which are seen in their vicinity. 
 The ancient sect of the Guebres or Parsees, distinguished 
 from all other sects as the worshippers of fire, had their 
 origin in Persia; but, being scattered by persecution, 
 they sought an asylum on the shores of India. Those 
 who refused to expatriate themselves continued to inhabit 
 the shores of the Caspian Sea, and the cities of Ispahan, 
 Yezd, and Kerman. Their great fire temple called Attush 
 
FIRE TEMPLES OF THE GEUBRES. 371 
 
 Kudda stands in the vicinity of Badku, one of the largest 
 and most commodious ports in the Caspian. In the 
 neighbourhood of this town the earth is impregnated with 
 naphtha, an inflammable mineral oil, and the inhabitants 
 have no other fuel, and no other light, but what is derived 
 from this substance. 
 
 The remains of the ancient fire temples of the Guebres 
 are still visible about ten miles to the north-east of the 
 town. The temple in which the Deity is worshipped 
 under the form of fire is a space about thirty yards square, 
 surrounded with a low wall, and containing many apart- 
 ments. In each of these a small volcano of sulphureous 
 fire issues from the ground through a furnace or funnel in 
 the shape of a Hindoo altar. On closing the funnel the 
 fire is instantly extinguished, and by placing the ear at 
 the aperture a hollow sound is heard, accompanied with a 
 strong current of cold air, which may be lighted at 
 pleasure by holding to it any burning substance. The 
 flame is of a pale clear colour, without any perceptible 
 smoke, and emits a highly-sulphureous vapour, which 
 impedes respiration, unless when the mouth is .kept 
 beneath the level of the furnace. This action on the 
 lungs gives the Guebres a wan and emaciated appear- 
 ance, and oppresses them with a hectic cough, which 
 strangers also feel while breathing this insalubrious atmo- 
 sphere. 
 
 For about two miles in circumference, round the 
 principal fire, the whole ground, when scraped to the 
 depth of two or three inches, has the singular property of 
 being inflamed by a burning coal. In this case, however, 
 it does not communicate fire to the adjacent ground ; but 
 if the earth is dug up with a spade, and a torch brought 
 near it, an extensive, but instantaneous conflagration takes 
 place, in which houses have often been destroyed, and the 
 lives of the people exposed to imminent danger. 
 
372 LETTERS ON NATURAL MAGIC. 
 
 When the sky is clear and the weather serene, the 
 springs in their ebullition do not rise higher than two or 
 three feet ; but in gloomy weather, and during the pre- 
 valence of stormy clouds, the springs are in a state of the 
 greatest ebullition, and the naphtha, which often takes fire 
 spontaneously at the earth's surface, flows burning in 
 great quantities to the sea, which is frequently covered 
 with it, in a state of flame, to the distance of several 
 leagues from the shore. 
 
 Besides the fires in the temple there is a large one 
 which springs from a natural cliff in an open situation, 
 and which continually burns. The general space in 
 which this volcanic fire is most abundant is somewhat less 
 than a mile in circuit. It forms a low flat hill sloping to 
 the sea, the soil of which is a sandy earth mixed with 
 stones. Mr. Forster did not observe any violent eruption 
 of flame in the country around the Attush Kudda ; but 
 Kinneir informs us, that the whole country round Badku 
 has at times the appearance of being enveloped in flames. 
 "It often seems," he adds, "as if the fire rolled down 
 from, the mountains in large masses, and with incredible 
 velocity; and during the clear moonshine nights of 
 November and December, a bright blue light is observed 
 at times to cover the whole western range. The fire does 
 not consume, and if a person finds himself in the middle 
 of it no warmth is felt." 
 
 The inhabitants apply these natural fires to domestic 
 purposes, by sinking a hollow cane or merely a tube of 
 paper, about two inches in the ground, and by blowing 
 upon a burning coal held near the orifice of the tube, 
 there issues a slight flame, which neither burns the cane 
 nor the paper. By means of these canes or paper tubes, 
 from which the fire issues, the inhabitants boil the water 
 in their coffee-urns, and even cook different articles of 
 food. The flame is put out by merely plugging up the 
 
SPRINGS OF INFLAMMABLE GAS. 373 
 
 orifice. The same tubes are employed for illuminating 
 houses that are not paved. The smell of naphtha is of 
 course diffused through the house, but after any person is 
 accustomed to it it ceases to be disagreeable. The 
 inhabitants also employ this natural fire in calcining 
 lime. The quantity of naphtha procured in the plain to 
 the south-east of Badku is enormous. It is drawn from 
 wells, some of which yield from 1000 to 1500 Ibs. per day. 
 As soon as these wells are emptied, they fill again till the 
 naphtha rises to its original level. * 
 
 Inflammable gases issuing from the earth have been 
 used both in the old and the new world for domestic 
 purposes. In the salt mine of Gottesgabe at Rheims, in 
 the county of Fecklenburg, there is a pit called the Pit of 
 the Wind, from which a constant current of inflammable 
 gas has issued for sixty years. M. Boeder, the inspector 
 of the mines, has used this gas for two years not only as 
 a light, but for all the purposes of domestic economy. In 
 the pits which are not worked he collects the gas and 
 conveys it in tubes to his house. It burns with a white 
 and brilliant flame, has a density of about 0'66, and con- 
 tains traces of carbonic acid gas and sulphuretted hydro- 
 gen.f 
 
 Near the village of Fredonia in North America, on the 
 shores of Lake Erie, are a number of burning springs as 
 they are called. The inflammable gas which issues from 
 these springs is conveyed in pipes to the village, which is 
 actually lighted by them.J 
 
 In the year 1828, a copious spring of inflammable gas 
 was discovered in Scotland in the bed of a rivulet which 
 crosses the north road between Glasgow and Edinburgh, 
 a little to the east of the seventh mile-stone from Glasgow, 
 
 * See Former's Travels, and Kinneirs Geog. Memoir. 
 t Edinburgh Journal of Science, No. xv. p. 183. 
 1 Id. Id. 
 
374 LETTERS ON NATURAL MAGIC. 
 
 and only a few fyundred yards from the house of Bedlay. 
 The gas is said to issue for more than half a mile along 
 the banks of the rivulet. Dr. Thomson, who has analysed 
 the gas, saw it issuing only within a space about fifty 
 yards in length, and about half as much in breadth. 
 " The emission of gas was visible in a good many places 
 along the declivity to the rivulet in the immediate 
 neighbourhood of a small farm-house. The farmer had 
 set the gas on fire in one place about a yard square, out of 
 which a great many small jets were issuing. It had 
 burnt without interruption during five weeks, and the soil 
 (which was clay) had assumed the appearance of pounded 
 brick all around. 
 
 " The flame was yellow and strong, and resembled 
 perfectly the appearance which carburetted hydrogen gas or 
 fire damp presents when burnt in daylight. But the 
 greatest issue of gas was in the rivulet itself, distant 
 about twenty yards from the place where the gas was 
 burning. The rivulet when I visited the place was 
 swollen and muddy, so as to prevent its bottom from being 
 seen. But the gas issued up through it in one place with 
 great violence, as if it had been in a state of compression 
 under the surface of the earth ; and the thickness of the 
 jet could not be less than two or three inches in diameter. 
 We set the gas on fire as it issued through the water. 
 It burnt for some time with a good deal of splendour ; 
 but as the rivulet was swollen and rushing along with 
 great impetuosity, the regularity of the issue was neces- 
 sarily disturbed, and the gas was extinguished." Dr. 
 Thomson found this gas to consist of two volumes of 
 hydrogen gas and one volume of vapour of carbon ; and 
 as its specific gravity was 0*555, and as it issues in great 
 abundance, he remarks that it might be used for filling 
 air-balloons. "Were we assured," he adds, "that it 
 would continue to issue in as great abundance as at pre- 
 
NATURAL LIGHTHOUSE OF MARACAYBO. 375 
 
 sent, it might be employed in lighting the streets of 
 Glasgow."* 
 
 A very curious natural phenomenon, called the Lantern 
 or Natural Lighthouse of Maracaybo, has been witnessed 
 in South America. A bright light is seen every night on 
 a mountainous and uninhabited spot on the banks of the 
 river Catatumbo, near its junction with the Sulia. It is 
 easily distinguished at a greater distance than forty 
 leagues, and as it is nearly in the meridian of the opening 
 of the Lake of Maracaybo, navigators are guided by it as 
 by a lighthouse. This phenomenon is not only seen from 
 the sea coast but also from the interior of the country, 
 at Merida, for example, where M. Palacios observed it for 
 two years. Some persons have ascribed this remarkable 
 phenomenon to a thunderstorm, or to electrical explosions, 
 which might take place daily in a pass in the mountains ; 
 and it has even been asserted that the rolling of thunder is 
 heard by those who approach the spot. Others suppose it 
 to be an air volcano, like those on the Caspian Sea, and 
 that it is caused by asphaltic soils like those of Mena. 
 It is more probable, however, that it is a sort of carburetted 
 hydrogen, as hydrogen gas is disengaged from the ground 
 in the same district. f 
 
 Grand as the chemical operations are which are going 
 on in the great laboratory of Nature, and alarming as their 
 effects appear when they are displayed in the terrors of 
 the earthquake and the volcano, yet they are not more 
 wonderful to the philosopher than the minute though 
 analogous operations which are often at work near our 
 own persons, unseen and unheeded. It is not merely in 
 the bowels of the earth that highly-expansive elements are 
 imprisoned and restrained, and occasi9nally called into 
 tremendous action by the excitation of heat and other 
 
 * Edinburgh Journal of Science, No. i. New Series, pp. 71 75. 
 f Humboldt's Personal Narrative, Vol. iv. p. 254, note. 
 
376 LETTERS ON NATURAL MAGIC. 
 
 causes. Fluids and vapours of a similar character exist 
 in the very gems and precious stones which science has 
 contributed to luxury and to the arts. 
 
 In examining with the microscope the structure of 
 mineral bodies, I discovered in the interior of many of the 
 gems thousands of cavities of various forms and sizes. 
 Some had the shape of hollow and regularly-formed 
 crystals : others possessed the most irregular outline, and 
 consisted of many cavities and branches united without 
 order, but all communicating with each other. These 
 cavities sometimes occurred singly, but most frequently in 
 groups forming strata of cavities, at one time perfectly flat 
 and at another time curved. Several such strata were 
 often found in the same specimen, sometimes parallel to 
 each other, at other times inclined, and forming all 
 varieties of angles with the faces of the original crystal. 
 
 These cavities, which occurred in sapphire, clirysoberyl, 
 topaz, beryl, quartz, amethyst, peridot, and other substances, 
 were sometimes sufficiently large to be distinctly seen by 
 the naked eye, but most frequently they were so small as 
 to require a high magnifying power to be well seen, and 
 often they were so exceedingly minute that the highest 
 magnifying powers were unable to exhibit their outline. 
 
 The greater number of these cavities, whether large or 
 small, contain two new fluids different from any hitherto 
 known, and possessing remarkable physical properties. 
 These two fluids are in general perfectly transparent and 
 colourless, and they exist in the same cavity in actual 
 contact, without mixing together in the slightest degree. 
 One of them expands thirty times more than water ; and at 
 a temperature of about 80 of Fahrenheit it expands so as 
 to fill up the vacuity in the cavity. This will be under- 
 stood from the annexed figure, where A B C D is the 
 cavity, m n p o the highly-expansible fluid'in which at low 
 temperatures there is always a vacuity V, like an air-bubble 
 
VAPOUR CAVITIES IN MINERALS. 377 
 
 in common fluids, and A m n, Cop, the second fluid 
 occupying the angles A and C. When heat such as that 
 of the hand is applied to the specimen, the vacuity V 
 gradually contracts in size, and wholly vanishes at a 
 temperature of about 80, as shown in Fig. 76. The 
 fluids are shaded, as in these two figures, when they are 
 seen by light reflected from their surfaces. 
 
 Fig. 75. 
 
 When the cavities are large, as in Fig. 77, compared 
 with the quantity of expansible fluid m n p o, the heat 
 converts the fluid into vapour, an effect which is shown by 
 the circular cavity V becoming larger and larger till it 
 fills the whole space m no p. 
 
 Fig. 76. 
 
 When any of these cavities, whether they are filled with 
 fluid or with vapour, is allowed to cool, the vacuity V 
 reappears at a certain temperature. In the fluid cavities 
 the fluid contracts, and the small vacuity appears, which 
 grows larger and larger till it resumes its original size. 
 When the cavities are large several small vacuities make 
 
 2 c 
 
378 LETTERS ON NATURAL MAGIC. 
 
 their appearance and gradually unite into one, though they 
 sometimes remain separate. In deep cavities a very 
 remarkable phenomenon accompanies the reappearance of 
 the vacuity. At the instant that the fluid has acquired the 
 temperature at which it quits the sides of the cavity, an 
 effervescence or rapid ebullition takes place, and the 
 transparent cavity is for a moment opaque, with an infinite 
 number of minute vacuities, which instantly unite into one 
 that goes on enlarging as the temperature diminishes. In 
 the vapour cavities the vapour is reconverted by the cold 
 into fluid, and the vacuity V, Fig. 77, gradually contracts 
 till all the vapour has been precipitated. It is curious to 
 
 Fig. 77. 
 
 observe, when a great number of cavities are seen at once 
 in the field of the microscope, that the vacuities all dis- 
 appear and reappear at the same instant. 
 
 While all these changes are going on in the expansible 
 fluid, the other denser fluid at A and C, Figs. 75, 76, 
 remains unchanged either in its form or magnitude. On 
 this account I experienced considerable difiiculty in prov- 
 ing that it was a fluid. The improbability of two fluids 
 existing in a transparent state in absolute contact, without 
 mixing in the slightest degree, or acting upon each other, 
 induced many persons to whom I showed the phenomenon 
 to consider the lines m n op, Figs. 75, 76, as a partition 
 
CAVITIES IN MINERALS. 379 
 
 in the cavity, or the spaces A m n, C o p, either as filled 
 with solid matter, or as corners into which the expanding 
 fluid would not penetrate. The regular curvature, how- 
 ever, of the boundary line m n o p, and other facts, 
 rendered these suppositions untenable. 
 
 This difficulty was at last entirely removed by the 
 discovery of a cavity of the form shown in the annexed 
 figure, where A, B, and are three portions of the 
 expansible fluid separated by the interposition of the 
 second fluid D E F. The first portion A of the expansible 
 fluid had four vacuities V, X, Y, Z, while the other two 
 portions B, C had no vacuity. In order to determine if 
 the vacuities of the portions B, C had passed over to A, I 
 
 took an accurate drawing of the appearances at a tempera- 
 ture of 50, as shown in the figure, and I watched the 
 changes which took place in raising the temperature to 
 83. The portion A gradually expanded itself till it 
 filled up all the four vacuities V, X, Y, and Z ; but as 
 the portions B, C had no vacuities, they could expand 
 themselves only by pushing back the supposed second 
 fluid D E F. This effect actually took place. The 
 dense fluid quitted the side of the cavity at F. The two 
 portions B, C of the expansible fluid instantly united, and 
 the dense fluid having retreated to the limit m n n o, its 
 other limit advanced to p q r, thus proving it to be a real 
 fluid. This experiment, which I have often shown to 
 others, involves one of those rare combinations of circuin 
 
380 
 
 LETTERS ON NATURAL MAGIC. 
 
 stances which nature sometimes presents to us in order to 
 illustrate her most mysterious operations. Had the por- 
 tions B, C been accompanied, as is usual, with their 
 vacuities, the interposed fluid would have remained 
 immoveable between the two equal and opposite expan- 
 sions ; but owing to the accidental circumstance of these 
 vacuities having passed over into the other branch A of 
 the cavity, the fluid yielded to the difference of the 
 expansive forces between which it lay, and thus exhibited 
 its fluid character to the eye. 
 
 Fig. 79. 
 
 When we examine these cavities narrowly, we find that 
 they are actually little laboratories, in which chemical ope- 
 rations are constantly going on, and beautiful optical phe- 
 nomena continually displaying themselves. Let A B D C, 
 for example, be the summit of a crystallized cavity in 
 topaz, S S representing the dense, N N the expansible 
 fluid, bounded by a circular line abed, and V V the 
 vacuity in the new fluid, bounded by the circle e f g h. 
 If the face A B D C is placed under a compound micro- 
 scope, so that light may be reflected at an angle 
 less than that of total reflection, and if the observer now 
 looks through the microscope, the temperature of the 
 room being 50, he will see the second fluid S S shining 
 
FLUIDS IN MINERALS. 381 
 
 with a very feeble reflected light, the dense fluid N N 
 with a light perceptibly brighter, and the vacuity V V 
 with a light of considerable brilliancy. The boundaries 
 a 6 c d, e f g h are marked by a well-defined outline, and 
 also by the concentric coloured rings of thin plates produced 
 by the extreme thinness of each of the fluids at their edges. 
 If the temperature of the room is raised slowly to 
 58, a brown spot will appear at x in the centre of the 
 vacuity V V. This spot indicates the commencement of 
 evaporation from the expansible fluid below, and arises 
 from the partial precipitation of the vapour in the roof of 
 the cavity. As the heat increases, the brown spot en- 
 larges and becomes very dark. It is then succeeded by a 
 white spot, and one or more coloured rings rise in the 
 centre of the vacuity. The vapour then seems to form a 
 drop, and all the rings disappear by retiring to the centre, 
 but only to reappear with new lustre. During the 
 application of heat, the circle efgh contracts and dilates 
 like the pupil of the eye. When the vaporization is so 
 feeble as to produce only a single ring of one or two tints of 
 the second order, they vanish instantly by breathing upon 
 the crystal, but when the slight heat of the breath reaches the 
 fluid, it throws off fresh vapour, and the rings again appear. 
 If a drop of ether is put upon the crystal when the rings 
 are in a state of rapid play, the cold produced by its 
 evaporation causes them to disappear, till the temperature 
 again rises. When the temperature is perfectly uniform, 
 the rings are stationary, as shown between V and V in 
 Fig. 79 ; and it is interesting to observe the first ring 
 produced by the vapour swelling out to meet the first 
 ring at the margin of the fluid, and sometimes coming so 
 near it that the darkest parts of both form a broad black 
 band. As the heat increases, the vacuity V V diminishes, 
 and disappears at 79, exhibiting many curious phenomena 
 which we have not room to describe. 
 
382 LETTERS ON NATURAL MAGIC. 
 
 Having fallen upon a method of opening the cavities, 
 and looking at the fluids, I was able to examine their 
 properties with more attention. When the expansible 
 fluid first rises from the cavity upon the surface of the 
 topaz, it neither remains still like the fixed oils, nor 
 disappears like evaporable fluids. Under the influence, 
 no doubt, of heat and moisture it is in a state of constant 
 motion, now spreading itself on a thin plate over a large 
 surface, and now contracting itself into a deeper and 
 much less extended drop. These contractions and exten- 
 sions are marked by very beautiful optical phenomena. 
 When the fluid has stretched itself out into a thin plate, it 
 ceases to reflect light like the thinnest part of the soap- 
 bubble, and when it is again accumulated into a thicker 
 drop, it is covered with the coloured rings of thin 
 plates. 
 
 After performing these motions, which sometimes last 
 for ten minutes, the fluid suddenly disappears, and leaves 
 behind it a sort of granular residue. When examining 
 this with a single microscope, it again started into a fluid 
 state, and extended and contracted itself as before. This 
 was owing to the humidity of the hand which held the 
 microscope, and I have been able to restore by moisture 
 the fluidity of these grains twenty days after they were 
 formed from the fluid. This portion was shown to the 
 Reverend Dr. Fleming, who remarked that, had he 
 observed it accidentally, he would have ascribed its 
 apparent vitality to the movements of some of the animals 
 of the genus Planaria. 
 
 After the cavity has remained open for a day or two, the 
 dense fluid comes out and quickly hardens into a trans- 
 parent and yellowish resinous-looking substance, which 
 absorbs moisture, though with less avidity than the other. 
 It is not volatilized by heat, and is insoluble in water 
 and alcohol. It readily dissolves, however, with efferves- 
 
NEW FLUIDS IN MINERALS. 38H 
 
 cence in the sulphuric, nitric, and muriatic acids. The 
 residue of the expansible fluid is volatilized by heat, and 
 is dissolved, but without effervescence, in the above-men- 
 tioned acids. The refractive power of the dense fluid is 
 about 1'295, and of the expansible one 1*131. 
 
 The particles of the dense fluid have a very powerful 
 attraction for each other and for the mineral which con- 
 tains them, while those of the expansible fluid have a 
 very slight attraction for one another, and also for the 
 substance of the mineral. Hence the two fluids never 
 mix, the dense fluid being attracted to the angles of angu- 
 lar cavities, or filling the narrow necks by which two 
 cavities communicate. The expansible fluid, on the other 
 hand, fills the wide parts of the cavities, and in deep and 
 round cavities it lies above the dense fluid. 
 
 When the dense fluid occupies the necks which join two 
 cavities, it performs the singular function of a fluid 
 valve, opening and shutting itself according to the expan- 
 sions or contractions of the other fluid. The fluid valves 
 thus exhibited in action may suggest some useful hints to 
 the mechanic and the philosopher, while they afford 
 ground of curious speculation in reference to the functions 
 of animal and vegetable bodies. In the larger organiza- 
 tions of ordinary animals, where gravity must in general 
 overpower, or at least modify, the influence of capillary 
 attraction, such a mechanism is neither necessary nor 
 appropriate ; but, in the lesser functions of the same 
 animals, and in almost all the microscopic structures of 
 the lower world, where the force of gravity is entirely 
 subjected to the more powerful energy of capillary forces, 
 it is extremely probable that the mechanism of immiscible 
 fluids and fluid valves is generally adopted. 
 
 In several cavities in minerals I have found crystal- 
 lised and other bodies, sometimes transparent crystals, 
 sometimes black spicular crystals, and sometimes black 
 
384 LETTERS ON NATURAL MAGIC. 
 
 spheres, all of which are moveable within the cavity. In 
 some cavities the two new fluids occur in an indurated 
 state, and others I have found to be lined with a powdery 
 matter. This last class of cavities occurred in topaz, and 
 they were distinguished from all others by the extraordi- 
 nary beauty and symmetry of their form. One of these 
 cavities represented a finely-ornamented sceptre, and, 
 what is still more singular, the different parts of which it 
 is composed lay in different planes. 
 
 When the gem which contains the highly-expansive 
 fluid is strong, and the cavity not near the surface, heat 
 may be applied to it without danger ; but in the course of 
 my experiments on this subject, the mineral has often 
 burst with a tremendous explosion, and in one case 
 wounded me on the brow. An accident of the same kind 
 occurred to a gentleman, who put a crystal into his mouth 
 for the purpose of expanding the fluid. The specimen 
 burst with great force and cut his mouth, and the fluid 
 which was discharged from the cavity had a very disagree- 
 able taste. 
 
 In the gems which are peculiarly appropriated for 
 female ornaments, cavities containing the expansible fluid 
 frequently occur, and if these cavities should happen to be 
 very near the surface or the edge of the stonej the fever f 
 heat of the body might be sufficient to burst them with an 
 alarming and even dangerous explosion. I have never 
 heard of any such accident having occurred ; but if it has, 
 or if it ever shall occur, and if its naturally marvellous 
 character shall be heightened by any calamitous results, the 
 phenomena described in the preceding pages will strip it 
 of its wonder. 
 
 There are no facts in chemistry more interesting than 
 those which relate to the changes of colour which are 
 produced by the mixture of fluids, and to the creation of 
 brilliant colours by the combination of bodies in which no 
 
CHANGE OF COLOUK IN CLOTHES. 385 
 
 colouring matter is visible. Feats of this kind are too 
 common and too generally known to require to be noticed 
 in a work like this. The art of producing such changes 
 was known to some of the early impostors, who endea- 
 voured to obtain a miraculous sanction to their particular 
 dogmas. Marcos, the head of one of the sects that wished 
 to engraft paganism upon Christianity, is said to have 
 filled three transparent glasses with white wine, and while 
 he prayed, the wine in one of the glasses became red like 
 blood, that in another became purple, and that in the third 
 sky-blue. Such transformations present no difficulty to 
 the chemist, There are several fluids, such as some of the 
 coloured juices of plants, which change their colour 
 rapidly and without any additional ingredient; and in 
 other cases, there would be no difficulty in making addi- 
 tions to fluids, which should produce a change of colour at 
 any required instant. 
 
 A very remarkable experiment of an analogous nature 
 has been publicly exhibited in modern times. Professor 
 Beyruss, who lived at the court of the Duke of Brunswick, 
 one day pronounced to his highness that the dress which 
 he wore should during dinner become red ; and the change 
 actually took place to the astonishment of the prince and 
 the rest of his guests. M. Vogel, who has recorded this 
 curious fact, has not divulged the secret of the German 
 chemist ; but he observes, that, if we pour lime-water into 
 the juice of beet-root, we shall obtain a colourless liquid ; 
 and that a piece of white cloth dipped in this liquid and 
 dried rapidly will in a few hours become red by the mere 
 contact of air. M. Vogel is also of opinion that this 
 singular effect would be accelerated in an apartment where 
 champagne or other fluids charged with carbonic acid are 
 poured out in abundance. 
 
 Among the wonders of chemistry we must number the 
 remarkable effects produced upon the human frame by the 
 
386 LETTERS ON NATURAL MAGIC. 
 
 inhalation of paradise or intoxicating gas, as it has been 
 called. This gas is known to chemists by the name of the 
 nitrous oxide, or the gaseous oxide of azote, or the protoxide 
 of nitrogen. It differs from atmospheric air only in the 
 proportion of its ingredients, atmospheric air being com- 
 posed of twenty-seven parts of oxygen and seventy-three of 
 nitrogen, while the nitrous oxide consists of thirty-seven 
 parts of oxygen and sixty-seven of nitrogen. The most 
 convenient way of procuring the gas is to expose nitrate of 
 ammonia in a tubulated glass retort to the heat of an 
 argand's lamp between 400 and 500 of Fahrenheit. The 
 salt first melts ; bubbles of gas begin to rise from the 
 mass, and in a short time a brisk effervescence takes place, 
 which continues till all the salt has disappeared. The 
 products of this operation are the nitrous oxide and 
 water, the watery vapour being condensed in the neck of 
 the retort while the gas is received over water. The gas 
 thus obtained is generally white, and hence, when it is 
 to be used for the purposes of respiration, it should remain 
 at least an hour over water, which will absorb the small 
 quantity of acid and of nitrate of ammonia which adhere 
 to it. A pound of the nitrate of ammonia will in this way 
 yield five cubic feet of gas fit for the purpose of inhala- 
 tion. 
 
 It was discovered by Sir Humphry Davy, that this gas 
 could be safely taken into the lungs, and that it was 
 capable of supporting respiration for a few minutes. In 
 making this experiment he was surprised to find that it 
 produced a singular species of intoxication, which he thus 
 describes : " I breathed," says he, " three quarts of oxide 
 from and into a silk bag for more than half a minute 
 without previously closing my nose or exhausting my 
 lungs. The first inspiration caused a slight degree of 
 giddiness. This was succeeded by an uncommon sense of 
 fulness in the head, accompanied with loss of distinct 
 
EFFECTS OF INTOXICATING GAS. 387 
 
 sensation and voluntary power, a feeling analogous to that 
 produced in the first stage of intoxication, but unattended 
 by pleasurable sensations." In describing the effects of 
 another experiment, he says, " Having previously closed 
 my nostrils and exhausted my lungs, I breathed four 
 quarts of nitrous oxide from and into a silk bag. The 
 first feelings were similar to those produced in the last 
 experiment, but in less than half a minute, the respiration 
 being continued, they diminished gradually, and were 
 succeeded by a highly-pleasurable thrilling, particularly 
 in the chest and the extremities. The objects around me 
 became dazzling, and my hearing more acute. Towards 
 the last respiration the thrilling increased, the sense of 
 muscular power became greater, and at last an irresistible 
 propensity to action was indulged in. I recollect but 
 indistinctly what followed ; I knew that my motions were 
 varied and violent. These effects very rarely ceased after 
 respiration. In ten minutes I had recovered my natural 
 state of mind. The thrilling in the extremities continued 
 longer than the other sensations. This experiment was 
 made in the morning; no languor or exhaustion was 
 consequent, my feelings through the day were as usual, 
 and I passed the night in undisturbed repose." 
 
 In giving an account of another experiment with this 
 gas, Sir Humphry thus describes his feelings : " Imme- 
 diately after my return from a long journey, being 
 fatigued, I respired nine quarts of nitrous oxide, having 
 been precisely thirty-three days without breathing any. 
 The feelings were different from those I had experienced 
 on former experiments. After the first six or seven 
 respirations, I gradually began to lose the perception of 
 external things, and a vivid and intense recollection of 
 some former experiments passed through my mind, so 
 that I called out, ' what an annoying concatenation of 
 ideas.'" 
 
388 LETTERS ON NATURAL MAGIC. 
 
 Another experiment made by the same distinguished 
 chemist was attended by still more remarkable results. 
 He was shut up in an air-tight breathing box, having a 
 capacity of about nine and a-half cubic feet, and he allowed 
 himself to be habituated to the excitement of the gas, 
 which was gradually introduced. After having undergone 
 this operation for an hour and a quarter, during which 
 eighty quarts of gas were thrown in, he came out of the 
 box and began to respire twenty quarts of unmingled 
 nitrous oxide. " A thrilling," says he, " extending from 
 the chest to the extremities, was almost immediately pro- 
 duced. I felt a sense of tangible extension, highly plea- 
 surable in every kind, my visible impressions were 
 dazzling, and apparently magnified. I heard distinctly 
 every sound in the room, and was perfectly aware of my 
 situation. By degrees, as the pleasurable sensation in- 
 creased, I lost all connection with external things ; trains 
 of vivid visible images rapidly passed through my mind, 
 and were connected with words in such a manner as to 
 produce perceptions perfectly novel. I existed in a world 
 of newly connected and newly modified ideas. When I 
 was awakened from this same delirious trance by Dr. King- 
 lake, who took the bag from my mouth, indignation and pride 
 were the first feelings produced by the sight of the persons 
 about me. My emotions were enthusiastic and sublime, 
 and for a moment I walked round the room, perfectly 
 regardless of what was said to me. As I recovered my 
 former state of mind, I felt an inclination to communicate 
 the discoveries I had made during the experiment. I 
 endeavoured to recal the ideas ; they were feeble and 
 indistinct. One recollection of terms, however, presented 
 itself, and with the most intense belief and prophetic 
 manner I exclaimed to Dr. Kinglake, ' nothing exists but 
 thoughts ; the universe is composed of impressions, ideas, 
 pleasures, and pains.' " 
 
EFFECTS OF INHALING NITROUS OXIDE. 389 
 
 These remarkable properties induced several persons to 
 repeat the experiment of breathing this exhilarating 
 medicine. Its effects were, as might have been expected, 
 various in different individuals ; but its general effect was 
 to produce in the gravest and most phlegmatic the highest 
 degree of exhilaration and happiness, unaccompanied with 
 languor or depression. In some it created an irresistible 
 disposition to laugh, and in others a propensity to mus- 
 cular exertion. In some it impaired the intellectual func- 
 tions, and in several it had no sensible effect, even when it 
 was breathed in the purest state and in considerable 
 quantities. It would be an inquiry of no slight interest to 
 ascertain the influence of this gas over persons of various 
 bodily temperaments, and upon minds varying in their 
 intellectual and moral character. 
 
 Although Sir Humphry Davy experienced no unpleasant 
 effects from the inhalation of the nitrous oxide, yet such 
 effects are undoubtedly produced ; and there is reason to 
 believe that even permanent changes in the constitution 
 may be induced by the operation of this remarkable 
 stimulant. Two very interesting cases of this kind pre- 
 sented themselves to Professor Silliinan of Yale College, 
 when the nitrous oxide was administered to some of his 
 pupils. The students had been in the habit for several 
 years of preparing this gas and administering it to one 
 another, and these two cases were the only remarkable 
 ones which deserved to be recorded. We shall describe 
 them in Professor Silliman's own words : 
 
 4 ' A gentleman about nineteen years of age, of a san- 
 guine temperament, and cheerful temper, and in the most 
 perfect health, inhaled the usual quantity of the nitrous 
 oxide when prepared in the ordinary manner. Imme- 
 diately his feelings were uncommonly elevated, so that, 
 as he expressed it, he could not refrain from dancing and 
 shouting. Indeed to such a degree was he excited, that 
 
390 LETTERS ON NATURAL MAGIC. 
 
 he was thrown into a frightful fit of delirium, and his 
 exertions became so violent, that after a while he sunk to 
 the earth exhausted, and there remained, until having by 
 quiet in some degree recovered his strength, he again 
 arose only to renew the most convulsive muscular efforts, 
 and the most piercing screams and cries ; within a few 
 moments, overpowered by the intensity of the paroxysm, 
 he again fell to the ground apparently senseless and pant- 
 ing vehemently. The long continuance and violence of 
 the affection alarmed his companions, and they ran for 
 professional assistance. They were, however, encouraged 
 by the person to whom they applied to hope that he would 
 come out of his trance without injury, but for the space 
 of two hours these symptoms continued ; he was perfectly 
 unconscious of what he was doing, and was in every 
 respect like a maniac. He states, however, that his feelings 
 vibrated between perfect happiness and the most consum- 
 mate misery. In the course of the afternoon, and after 
 the first violent effects had subsided, he was compelled to 
 lie down two or three times, from excessive fatigue, 
 although he was immediately aroused upon any one's 
 entering the room. The effects remained in a degree for 
 three or four days, accompanied by a hoarseness, which he 
 attributed to the exertion made while under the immediate 
 influence of the gas. This case should produce a degree 
 of caution, especially in persons of a sanguine tempera- 
 ment, whom, much more frequently than others, we have 
 seen painfully and even alarmingly affected." 
 
 The other case described by Professor Silliman was 
 that of a man of mature age, and of a grave and respectable 
 character. " For nearly two years previous to his taking 
 the gas his health had been very delicate, and his mind 
 frequently gloomy and depressed. This was peculiarly 
 the case for a few days immediately preceding that time, 
 and his general state of health was such that he was 
 
CONCLUSION. 391 
 
 obliged almost entirely to discontinue his studies, and was 
 about to have recourse to medical assistance. In this 
 state of bodily and mental debility he inspired about 
 three quarts of nitrous oxide. The consequences were, 
 an astonishing invigoration of his whole system, and the 
 most exquisite perceptions of delight. TJiese were mani- 
 fested by an uncommon disposition for pleasantry and 
 mirth, and by extraordinary muscular power. The effects 
 of the gas were felt without diminution for at least thirty 
 hours, and in a greater or less degree for more than a 
 week. 
 
 " But the most remarkable effect was that upon the 
 organs of taste. Antecedently to taking the gas,' he 
 exhibited no peculiar choice in the articles of food, but 
 immediately subsequent to that event, he manifested a taste 
 for such things only as were sweet, and for several days ate 
 nothing but sweet calx. Indeed this singular taste was 
 carried to such excess, that he used sugar and molasses not 
 only upon his bread and butter and lighter food, but upon his 
 meat and vegetables. This he continues to do even at the 
 present time, and although eight weeks have elapsed since 
 he inspired the gas, he is still found pouring molasses over 
 beef, fish, poultry, potatoes, cabbage, or whatever animal or 
 vegetable food is placed before him. . 
 
 " His health and spirits since that time have been uni- 
 formly good, and he attributes the restoration of his 
 strength and mental energy to the influence of the nitrous 
 oxide. He is entirely regular in his mind, and now ex- 
 periences no uncommon exhilaration, but is habitually 
 cheerful, while before he was as habitually grave, and 
 even to a degree gloomy." 
 
 Such is a brief and a general account of the principal 
 phenomena of Nature, and the most remarkable deductions 
 of science, to which the name of Natural Magic has been 
 
392 LETTERS ON NATURAL MAGIC. 
 
 applied. If those who have not hitherto sought for in- 
 struction and amusement in the study of the material 
 world shall have found a portion of either in the preceding 
 pages, they will not fail to extend their inquiries to other 
 popular departments of science, even if they are less 
 marked with the attributes of the marvellous. In every 
 region of space, from the infinitely distant recesses of the 
 heavens to the "dark unfathomed caves of ocean," the 
 Almighty has erected monuments of miraculous grandeur, 
 which proclaim the power, the wisdom, and the beneficence 
 of their author. The inscriptions which they bear the 
 handwriting which shines upon their walls appeal to the 
 understanding and to the affections, and demand the ad- 
 miration and the gratitude of every rational being. To 
 remain willingly ignorant of these revelations of the 
 Divine Power is a crime next to that of rejecting the 
 revelation of the Divine will. Knowledge, indeed, is at 
 once the handmaid and the companion of true religion. 
 They mutually adorn and support each other ; and beyond 
 the immediate circle of our secular duties, they are the 
 only objects of rational ambition. While the calm deduc- 
 tions of reason regulate the ardour of Christian zeal, the 
 warmth of a holy enthusiasm gives a fixed brightness to 
 the glimmering lights of knowledge. 
 
 It is one of the darkest spots in/ the history of man that 
 these noble gifts have been so seldom combined. In the 
 young mind alone can the two kindred seeds be effectually 
 sown ; and among the improvements which some of our 
 public institutions require, we yet hope to witness a 
 national system of instruction, in which the volumes of 
 Nature and of Eevelation shall be simultaneously perused. 
 
 D. BEEWSTER. 
 
ADDITIONAL PHENOMENA 
 
 OF 
 
 NATURAL MAGIC. 
 
 CHAPTEE I. 
 
 Optical illusions The Mirage of the desert Belzoni's description 
 Quintus Curtius's account Probable cause Apathy of the Arabs 
 and neglect of the example of the patriarchs Prospect of a 
 remedy Optical illusion of Mr. W. G. S. Association of ideas 
 Cause of vividness of such phenomena And of dreams over 
 ordinary events Magic lantern improved by photography 
 and the improvements in artificial light, &c. Professor Pepper's 
 ghost The decapitated head speaking Floating cherubs The 
 automatic Leotard The high merits of these Polytechnic in- 
 ventions Herr Frikel's " Masks and Faces " Aurora Borealis 
 Sensitive flames Shadow pantomime. 
 
 ON the subject of optical illusions little falls to be added 
 to the preceding Letters, beyond what Sir David Brewster 
 has already so fully written. The mirage in the Arctic 
 regions has been considerably dilated on in more recent 
 voyages than those Sir David has referred to, but 
 nothing has been added to the interest of this phenomenon 
 which would be regarded as more than mere amplification 
 of details in the present volume. The following, on 
 what is called the mirage in the desert, however, possesses 
 sufficiently distinctive features to justify notice. M. 
 Belzoni, writing of the desert in Upper Egypt, on the 
 western side of the Eed Sea, which he crossed, and which 
 
 2 D 
 
394 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 is parallel with the great desert on the eastern side, the 
 scene of the wanderings of the Israelites, says : " Generally 
 speaking, in a desert there are few springs of water: 
 some of them at the distance of four, six, and eight days' 
 journey from one another, and not all of sweet water : 
 on the contrary, it is generally salt or bitter, so that if 
 the thirsty traveller drinks it, it increases his thirst, and 
 he suffers more than before. But when the calamity 
 happens that when the next well, which is so anxiously 
 sought for, is found dry, the misery of such a situation 
 cannot be well described. The camels, which afford the 
 only means of escape, are so thirsty that they cannot 
 proceed to another well ; and if the travellers kill them, 
 to extract the little liquid which remains in their 
 stomachs, they themselves cannot advance any further. 
 The situation must be dreadful, and admits of no resource. 
 Many perish victims of the most horrible thirst. It is 
 then that the value of a cup of water is really felt. He 
 that has a zenzabra of it is the richest of all. In such 
 a case there is no distinction. If the master has none 
 the servant will not give it to him ; for very few are the 
 instances where a man will voluntarily lose his life to 
 save that of another, particularly in a caravan in the 
 desert, where people are strangers to each other. What a 
 situation for a man, though a rich one, perhaps the 
 owner of all the caravans! He is dying for a cup of 
 water no one gives it to him : he offers all he possesses 
 no one hears him : they are all dying though by 
 walking a few hours further they might be saved. If the 
 camels are lying down, and cannot be made to rise, no 
 one has strength to walk. Only he that has a glass of 
 that precious liquor lives to walk a mile further, and 
 perhaps dies too. * * * In short, to be thirsty in the 
 desert without water, exposed to the burning sun without 
 shelter, and no hopes of finding either, is the most 
 
MIRAGE IN THE DESERT. 395 
 
 terrible situation that a man can be placed in, and one 
 of the greatest sufferings that a human being can sustain : 
 the eyes grow inflamed, the tongue and lips swell, a 
 hollow sound is heard in the ears, which brings on 
 deafness, and the brain appears to grow thick and inflamed. 
 All these feelings arise from the want of a little water. 
 In the midst of all this misery, the deceitful morasses appear 
 before the traveller at no great distance something like a 
 lalfe or river of clear fresh water. If, perchance, a 
 traveller is not undeceived he hastens his pace to reach it 
 sooner : the more he advances towards it the more it recedes 
 from him, till at last it vanishes entirely, and the deluded 
 passenger often asks where is the water lie saw at no great 
 distance ? He can scarcely believe that he was so deceived ; lie 
 protests that he saw the waves running before the wind, and 
 the reflection of the high rocks in the water." Elsewhere 
 M. Belzoni gives the following further particulars of 
 this desert mirage : " It generally appears like a still lake, 
 so unmoved by the wind that everything above is to be 
 seen most distinctly reflected by it. If the wind agitate 
 any of the plants that rise above the horizon of the 
 mirage the motion is seen perfectly at a great distance. 
 If the traveller stands elevated much above the mirage 
 the apparent water seems less united and less deep ; for 
 as the eyes look down upon it, there is not thickness 
 enough in the vapour on the surface of the ground to 
 conceal the earth from the sight ; but if the traveller be 
 on a level with the horizon of the mirage he cannot see 
 through it, so that it appears to him clear water. By 
 putting my head first to the ground, and then mounting 
 a camel, the height of which from the ground might 
 have been about ten feet at the most, I found a great 
 difference in the appearance of the mirage. On approach- 
 ing it, it becomes thinner, and appears as if agitated by 
 the wind, like a field of ripe corn. It gradually vanishes 
 
396 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 as the traveller approaches, and at last entirely disappears 
 when he is on the spot." Belzoni's Narrative, pp. 341- 
 343, and p. 196. This description substantially coincides 
 with that of Quintus Curtius, who, in detailing the 
 passage of Alexander the Great and his army through 
 the deserts of Sogdiana, says : " Amidst a dearth of 
 water, despair of obtaining any created thirst before it 
 was excited by nature. Throughout four hundred stadia 
 not a drop of water springs. As soon as the summer 
 heat pervades the sand everything is dried up as in a 
 burning kiln. Steaming from the fervid expanse, which 
 appears like a surface of sea, a cloudy vapour darkens the 
 day," &c. Quint. Curt., lib. vii. c. 5. The phenomenon 
 described by these writers is supposed to be produced by 
 a decrease in the density of the stratum of the atmosphere 
 in immediate contact with the ground, arising from the 
 intense heat of the sun upon the sand; but there is 
 probably also a small amount of vapour or steam at the 
 high temperature of invisibility along with it, and which 
 would in that state rather increase the inconvenience 
 of the traveller, and even aid to blister his skin, as 
 Curtius further remarks, than modify the heat and 
 drought, or help him ; for more recent travellers seem to 
 indicate from their observations that there is water at no 
 very great depth below the sand. And, indeed, it is a 
 remarkable fact that the Arabs, with the well-remembered 
 examples of the patriarchs before them, whose Artesian 
 works remain, and are pointed out by them to this day, 
 should not have dug wells at convenient distances for 
 their caravan journeys, and established caravansaries 
 at them, to prevent the horrors Belzoni has described, 
 and with the fatal features of which they have had grim 
 familiarity down through all the ages of their history. 
 The desire for short routes and railway communication 
 will probably come to their aid at last, and accomplish 
 
OPTICAL ILLUSION OF MR. W. G. S. 397 
 
 this object by the sinking of Artesian wells and the 
 dissemination of streams of water along the surface of the 
 ground by means of steam pumps, which would soon be 
 sheltered by vegetation if water were steadily supplied, 
 for it is astonishing how rapidly the desert blooms and 
 becomes covered with verdure whenever plants find 
 moisture to support them. And there appears little 
 reason to doubt that these deserts are great basins full of 
 water, but only fuller still of sand. Dean Stanley, in 
 his " Sinai and Palestine," speaking of the general charac- 
 teristics of the wadys or valleys, says : " There is nearly 
 everywhere a thin, it might almost be said a transparent 
 coating of vegetation." 
 
 Allied to the class of optical illusions mentioned in Sir 
 David's third Letter, the following, communicated to the 
 editor by the gentleman by whom it was experienced, is 
 sufficiently distinctive to deserve notice. One day, not 
 many years since, Mr. W. G. S., the gentleman in question, 
 was after an interval of years walking along a picturesque 
 country road in the neighbourhood of Edinburgh, when 
 reaching a certain point he was suddenly, and without any 
 previous preparation for such a spectacle, surprised by the 
 appearance of a magnificent cavalcade of knights and 
 dames on horseback arrayed in the costume of the Middle 
 Ages, accompanied with a suitable following of squires 
 and other attendants, with hounds and hawks : many 
 of the ladies with falcons on their wrists, as if the party 
 were bent on hunting. The cavalcade consisted of a 
 numerous company, and defiled with gay but graceful 
 dignity, passed him and disappeared in a woodland path. 
 The gentleman stood riveted in surprise for some moments 
 after the spectacle had disappeared ; for, convinced it was 
 only an illusion, he was astonished at its vivid magnificence 
 and complete details. At length, overcoming his wonder, 
 he proceeded on his walk, still ruminating on the pageant 
 
398 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 lie had seen, and striving to explain it to himself, when he 
 at last recollected that in his boyhood, many years before, 
 when he had given himself up to the reading of romance- 
 literature, at the period when it was most in fashion, he 
 had been in the habit of identifying himself with the sub- 
 jects he had read ; and being of a peculiarly intense 
 character, with a highly-picturesque imagination, had on 
 many occasions during his solitary country rambles aban- 
 doned himself to the enthusiasm of the time and imagined 
 himself one of the characters in just such chivalrous and 
 romantic pageants ; and he then felt fully satisfied that 
 some peculiarity in the appearance of the road at the 
 point where he had just beheld the spectacle mentioned 
 had recalled the whole association of ideas connected with 
 a past visit to the spot, and revived in this vivid form a 
 day-dream of his youth. 
 
 The mere vividness, however, of such an incident was 
 its only peculiarity. The association of ideas is so strong 
 and so well known, that we can scarce hear certain subjects 
 mentioned, or look upon certain articles, without having at 
 once a long train of the past suggested to the mind's eye, 
 and the intensity with which the subject presents itself 
 often passes unnoticed on account of its being expected 
 and a matter of course. Thus the presence of an article 
 of furniture such as an old chair will set the fancy into a 
 trance of contemplation as to some departed and venerable 
 occupant, and the whole thought in connection with it will 
 be pictured by the mind, for it is a mistake to say we 
 think in language only ; we think in pictures also, just as 
 much as we dream in pictures, and the only reason why 
 such pictures do not strike us with surprise is that they 
 are, if not pictures resulting from direct volition, at all 
 events pictures tacitly acquiesced in, and therefore such as 
 we are mentally prepared for. It is in fact only when we 
 think without the will or consent that the imagery of the 
 
MAGIC LANTEEN. 399 
 
 mind, unfamiliar under that aspect, is more than usually, 
 vivid from the effect of surprise. Indeed, reality is in 
 much the same condition with us. We meet friends day 
 by day who have been the associates of our lives, and we 
 scarce realize the fact that they have been with us. A 
 familiar face may appear, a familiar step enter the study 
 while we are busily engaged, and pass out again without 
 our recognition, and scarcely with our consciousness that 
 they have been with us. But should any friend long 
 absent appear suddenly and unexpectedly in the same way, 
 surprise and the intensity of special recognition will be 
 evoked at once, and a vividness of the whole incident 
 impressed upon the mind which will produce the strongest 
 impression at the moment, and leave elements for per- 
 manent reflection afterwards when things common have 
 been long forgotten. The vividness of dreams is very 
 much, if not wholly, attributable to the same cause. The 
 will in our mental life to a certain extent directs and 
 controls the current of ideas under ordinary circumstances, 
 and with regard to real incidents, we are in contact with a 
 series of causes, all the associations and results of which 
 are regarded as matter of course, calculated on and looked 
 for. They are therefore looked forward to before they 
 take place, or so far foreknown as to have their interest 
 and novelty exhausted before they occur ; but dreams are 
 things out of the list of anticipation, for they never are, 
 when vivid or impressive, what we expected them to be ; 
 hence the impression of their novelty is not and cannot be 
 forestalled, and they strike us with as much vividness as 
 any surprising or unexpected incident in the eventualities 
 of life. 
 
 Among artificial illusions many ingenious novelties have 
 appeared of late years. The ingenious suggestions of Sir 
 David Brewster, before mentioned, for the improvement of 
 the magic lantern have been all more or less exceeded by 
 
400 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 the great progress of recent discovery. Photography has 
 given accuracy of detail and life-like intensity to the 
 subjects displayed by the lantern, while improvements in 
 the mechanism, together with lime ball, magnesium, and 
 other powerful means of illumination, have been success- 
 fully applied to produce almost a daylight clearness on 
 the screen compared with the darkness in which the 
 audience sits in viewing such objects. How far Sir David 
 had anticipated some of the most advanced improvements 
 by his suggestions however will appear from the following 
 passage in a recent publication compared with his letter 
 on this subject : 
 
 " An ingenious experimentalist, desirous of showing 
 various chemical phenomena by means of the magic 
 lantern, makes a glass tank, into which different liquids 
 or solutions may be poured, which will illustrate the effect 
 of refraction on light and other phenomena. If a pipette 
 be skilfully used to introduce some of the solutions into 
 the water in the tank, the appearance thrown on the 
 screen is that of a submarine volcano, pouring forth 
 clouds of smoke and torrents of lava, which, however, are 
 soon absorbed in the surrounding ocean. A solution of 
 cochineal in alcohol, similarly introduced, produces the 
 effect of a magnificent crimson fountain : a solution of 
 litmus appears as a delicate blue sky ; a few drops of acid 
 being let fall into this give a variety of forms and com- 
 binations, as of clouds seen in a sunset sky. Black, 
 stormy clouds may be produced by dropping into the 
 water a small quantity of sulphate of copper in solution 
 and weak ammonia ; and with dilute sulphuric acid and 
 ferrocyanide of potassium, other cloud-effects can be repre- 
 sented which have a most impressive appearance on the 
 screen. It is possible also to show the changes in colour 
 produced by chemical reaction, the decomposition of water 
 by a galvanic current, and the convection of heat by 
 
PROFESSOR PEPPER'S GHOST. SPEAKING HEAD, ETC. 401 
 
 liquids ; and to exhibit all these operations to a large 
 number of persons at once, opens a new application of the 
 magic lantern which clever operators will no doubt turn 
 to account ; any one familiar with the manipulation of 
 apparatus will know how to contrive the tanks for the 
 different purposes." 
 
 The eminently-ingenious Professor Pepper also, in 
 conjunction with the other talented gentlemen forming 
 the staff of the Koyal Polytechnic Institution of London, 
 has distinguished himself by great success not only 
 in showing all the illusions practised by charlatans who 
 claim a higher authority than mere skill and dexterity for 
 their seances, but in the forestalling by their inventive 
 genius discoveries which otherwise might have been used 
 in course of time to deceive and operate upon the super- 
 stitious by vile and unprincipled pretenders to the super- 
 natural. 
 
 Among other novelties, Professor Pepper's ghost, the 
 speaking head, floating cherubs, automatic Leotard, &c., 
 deserve special mention and the highest praise. The 
 ghost is got up in a very simple yet remarkably effective 
 way, and suggests the idea that the Professor must have 
 caught sight of his own image in a plate-glass window 
 more than once before he engaged in spirit-makiug. This 
 illusion is easily accomplished by placing a large sheet of 
 plate glass E F on the stage before a dark-green cloth under 
 a subdued light, and throwing the reflection of a person 
 acting the ghost upon it by having him placed in front in 
 such a position as to cause his image to appear at the 
 point desired. For this purpose the person acting the 
 ghost must be placed with a screen of dark-green cloth 
 behind him, as shown in the following diagram. In this 
 way the reflection of the dark-green cloth A B behind the 
 figure will not appear, but will blend with the colour of 
 the dark- green cloth C D behind the sheet of plate glass. 
 
402 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 while the figure will appear reflected alone. The light 
 being kept more subdued upon the stage than upon the 
 figure to be reflected, the presence of any real actor upon 
 the stage will appear less vivid under the subdued light 
 than that of the ghost. If the plate glass be so arranged 
 that the actor on the stage in approaching or passing the 
 shadow can go behind or in front of the plate glass at 
 pleasure, the illusion of passing through the shadow or 
 appearing to strike, stab, or grasp it in vain, will be very 
 perfectly shown. The distance between the figure and its 
 reflection at E F is necessarily circumscribed by the limits 
 of our space. The angularity of the glass to the audience, 
 so as to throw the image of the ghost only toward them, 
 and all other reflection on it in other directions, is easily 
 arranged. 
 
 The speaking head, floating cherubs, &c., are accom- 
 plished by similar arrangements of plate glass and dark 
 background. But in these cases the figures seen may, or 
 may not be in shadow or reflection, at the option of the con- 
 ductor. When not reflections, the arrangement may be 
 accomplished by having the plate glass divided into 
 pieces. Thus a half sheet from the bottom of the stage, 
 with a screen of green cloth in front of the performer, will 
 
POLYTECHNIC INVENTIONS. 403 
 
 conceal the whole body but the head, which may appear to 
 be resting on a pole or narrow pedestal in front of the 
 glass. In this way Blue Beard places the carefully- 
 embalmed head of a deceased wife, the victim of his 
 cruelty, upon the pedestal to look at. This head, if an 
 excellent wax likeness of some lady performer of the esta- 
 blishment, is easily put out of the way when being placed 
 on the pedestal and represented by the lady performer 
 herself, who appears from behind, showing only so much 
 of her head as replaces and represents the wax likeness. 
 Blue Beard then retires to smoke and contemplate, 
 when to his astonishment and horror the dead head 
 addresses him, opens its eyes, &c. This illusion is very 
 ingenious and perfect. Cherubs may be made to float 
 about by representing heads of children or young 
 performers in the same way, their bodies being concealed 
 by a screen of green cloth in front of the floating stage on 
 which they stand. The great advantage of the dark- 
 green cloth groundwork in blending, though in separate 
 pieces, as if it were only one continuous background, is of 
 great importance, together with such a subdued and 
 appropriate arrangement of the light as prevents the plate 
 glass from glancing and becoming apparent to the 
 audience, and the ingenious invention is capable of far 
 higher dramatic effects than it has yet been applied to. 
 Professor Pepper's ghosts, like those of Shakespeare, are 
 almost too refined and gentlemanly for any but those 
 delicate and metaphysical qualities of mind which ap- 
 preciate the characteristics of propriety and logical con- 
 nection in everything. The white sheet horror is more 
 suited to the modern sensational drama. But there 
 really is some defect in the representation of Shakes- 
 peare's grand ghost scenes, which modern science might 
 surely apply itself to remedy. The ghost of Hamlet's 
 father and others want a glistering, phosphorescent and 
 
404 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 self-lighted aspect to distinguish their spectral character 
 vividly from the living actors with whom they mingle, 
 and doubtless Shakespeare's own ideal was something of 
 this kind, though the resources of the time did not afford 
 very satisfactory means of realising it. The innocuous 
 allotropic phosphorus now in use, with perhaps some other 
 chemical appliances, might afford means of overcoming 
 this difficulty. 
 
 The automatic Leotard is another of those admirably- 
 achieved Polytechnic illusions which may be said to 
 surpass in some respects even the living prototype. This 
 figure is admirably formed, and its possible motions, with 
 their swing, are well kept within the range of easy 
 physical action in the natural joints. To the close 
 observer it becomes at once apparent, from the want of 
 bend in the elbow-joints and the complete circles per- 
 formed by the shoulders of the figure, that the hands and 
 inflexible arms are permanently fixed to the cross-bar of 
 the trapeze, which is made to revolve in any direction by 
 means of rods and wheels connected with its ends and 
 set in motion from above, the rods being concealed by 
 what appear to be the cords by which the whole is 
 suspended, which also have a manifest inflexibility and 
 an otherwise unnecessary thickness. These peculiarities, 
 however, are far from detracting from the merit of this 
 admirable Polytechnic invention. Professor Pepper 
 manfully disavows the power to work impossibilities. 
 He only aims at accomplishing apparent impossibilities 
 by the most skilful and graceful application of possible 
 means, and assuredly these are of them. To what 
 infamous purposes, by contrast, the ancient statecrafts and 
 priestcrafts would have turned these meritorious and 
 honourable ingenuities, had they known them, many a 
 passage in the preceding Letters of Sir David Brewster 
 will abundantly suggest. 
 
405 
 
 The illusion as to the direction of sight and the 
 expression of faces, mentioned in one of the preceding 
 Letters, has been further and most successfully illustrated 
 lately by the "Masks and Faces" of the talented and 
 ingenious Herr Frikel, who by the mere arrangement 
 of head-gear and appropriate accessories has shown 
 how readily the same face may be made to realise our 
 typical ideas of the European and Asiatic, Hindoo, 
 Chinese, Turk, or Tartar, &c., as well as the masculine or 
 feminine expression and countenance. Indeed our 
 attention or inattention to facts, which perhaps do or do 
 not strongly affect us, is apt to make us imagine there are 
 greater differences in some cases and less differences in 
 others than really exist. The man who would never 
 doubt, until confronted with one of Herr Frikel's trans- 
 formations, that he could at once tell, by the aspect of 
 the countenance, the difference between a German and a 
 Chinaman would be apt to deny the possibility of a 
 shepherd being able to distinguish every individual sheep 
 of a numerous flock which has been for a short time under 
 his care. Yet any one who takes the trouble to look 
 carefully at a flock of sheep driven through the streets 
 will be able to see that, even in the shape of the nose, 
 sheep are as much distinguished from each other in- 
 dividually by all the varieties of Eoman, Greek, and snub 
 nose as human beings are, and that all the other features 
 are equally marked by individual identity. Indeed, the 
 aphorism "as like as two peas" is by no means so very 
 close or proximate a resemblance as the expression appears 
 to assume. We doubt if there ever were two peas 
 exactly alike since the creation of the world, any more 
 than two kinds or specimens of handwriting. Nay, much 
 as identity in this latter respect is distinctively recog- 
 nisable, we doubt if any man ever wrote his own 
 signature exactly alike twice in the whole course of his 
 
406 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 life ; and yet a man with perfect integrity and justifiability 
 swears to his own handwriting, and others acquainted 
 with it do so also, in the perfect and conscientious 
 certainty of the fact. 
 
 One of the subjects which it appears justifiable to 
 introduce here, along with the associated subject of the 
 mirage which has been so interestingly treated by Sir 
 David Brewster, is the aurora borealis, which is displayed 
 with remarkable brilliance within the Arctic circle during 
 the prolonged winter darkness of that region, which is 
 much indebted to this splendid phenomenon for the relief 
 of its prolonged and inhospitable gloom. Those who 
 observe this phenomenon attentively will find that its 
 point of convergence, or the centre towards which its 
 " streamers " point, is generally identical with, or very 
 nearly approximate to, that point of the heavens which is 
 opposite to the sun during the manifestation of the 
 spectacle. It is a point, in fact, only seen in the northern 
 and southern regions beyond the range of the ecliptic, 
 while the sun is within that plane, and on the opposite 
 side of the earth, and everything conspires to show that 
 while the atmosphere of the world acts like a sphere of 
 glass enclosing the earth, by which the rays of the sun 
 are refracted as if they were intercepted by a globular or 
 double convex lens, these rays so refracted are converged 
 on the opposite side of this atmospheric lens, from the 
 edges of the terrestrial disc exposed to the sun, according 
 to the greater or less purity of the atmosphere under that 
 region forming the edge of the disc, and that the coloured 
 rays seen to prevail sometimes are mere prolongations of 
 the gorgeous tints of sunset or of dawn then prevailing at 
 those points of the workVs surface from which the re- 
 fraction takes place. The rapidity with which the aurora 
 darts its rays, and changes, is readily accounted for from 
 the presence of intercepting clouds, projecting ice, and 
 
SENSITIVE FLAMES. 407 
 
 mountain ranges, and other inequalities along the cir- 
 cumference of the earth's disc exposed to the solar action, 
 combined with the rapidity of the earth's motion (diurnal 
 and orbitual) with reference to the sun ; while the 
 weather which such an appearance is held to presage is 
 also accounted for by the atmospheric conditions necessary 
 to enable the phenomenon to take place. 
 
 One of the remarkable discoveries of recent scientific 
 inquiry is that of Mr. Barrett, late Assistant at the Royal 
 Institution, with regard to what are called " sensitive 
 flames." A metal pipe with an orifice of steatite, when 
 emitting such an amount of gas as to afford that quantity 
 of flame which a burner gives forth just before the flame 
 " roars," as we are accustomed to hear it called, from the 
 excessive pressure of the gas, furnishes a light which is 
 exceedingly sensitive to certain sounds. A grave sound 
 such as a low whistle will cause it to shoot out numerous 
 tongues of flame, which subside when the sound is discon- 
 tinued. By different arrangements of the burner this 
 may be varied. An aperture supplying a column of flame 
 of about two feet in length will cower and quiver under 
 the influence of certain sibilant sounds. Words contain- 
 ing the letters, s, x, and z, especially the former, power- 
 fully affect it even when pronounced at a considerable 
 distance from it. And a variety of manifestations may be 
 occasioned by certain notes of the pianoforte. Under one 
 set of conditions the effect being produced by high, and 
 under another by low notes. This peculiarity is mani- 
 festly the effect of vibration on highly-elastic elements, 
 which may either be the gas forming the supporter of 
 combustion, or the metallic orifice from which the flame 
 proceeds. Indeed, every element known is more or less 
 elastic, and it is quite possible to conceive that certain 
 sounds, by the peculiarity of their vibration, could shiver 
 solid bodies to pieces, and that the character of the sound, 
 
408 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 more than the power of the atmospheric concussion 
 involved, might produce the most serious consequences. 
 Who is not familiar with that most disagreeable of sounds, 
 the sharpening of a saw with a file, to recall the very 
 recollection of which is to conjure up a sensation of 
 horror ? It is not in such a case because our dislike is 
 arbitrary and capricious that we hate the sensation pro- 
 duced, but because it is really disagreeable, and to some 
 delicate constitutions has a positively injurious physical 
 effect, that repugnance to it prevails, and the nerves 
 shrink and quiver painfully beneath its action. 
 
 A very amusing novelty has recently been successfully 
 exhibited at one of the London amphitheatres, which may 
 be called " Shadow Pantomime." The body of the house 
 or room being darkened, a white screen is interposed 
 between the audience and the performers, with a light 
 behind it, by means of which the shadows of the per- 
 formers only are given projected on the screen. When 
 a performer approaches near to the light at the back of 
 the stage his shadow is greatly magnified and appears of 
 gigantic proportions, while the other performers approach- 
 ing nearer to the screen appear upon it by their shadows 
 of nearly their natural size. The effect is highly striking 
 and effective, as well as amusing, as the hand of an 
 individual near the light will appear larger by its shadow 
 on the screen than the whole body of an actor more 
 remote from the light, and nearer to the screen. Jack 
 the Giant Killer, and the adventures of Gulliver, admit of 
 a highly effective and comic representation by means of 
 this very ingenious adaptation of shadow, and the arrange- 
 ments are so simple and easily made that the amusements 
 of the nursery may be readily and greatly enhanced and 
 illustrated by it at absolutely no expense, and scarcely 
 any trouble. 
 
SUSPENDED ANIMATION. 409 
 
 CHAPTER II. 
 
 Life and suspended animation, or asphyxia Interment alive Pheno- 
 mena of the grave Coma, or extraordinarily long sleeps Sears 
 Toads found in rocks Tadpoles: separated vitality Polypes 
 Annelides, or worms Process of restoring severed parts Sus- 
 pended and restored animation Eotifera Reproductive powers 
 of animals and plants Divisibility of matter Facts beyond the 
 range of physics Extraordinary divisibility of life Ne w fact in 
 philosophy The philosophers of fixity Superiority of a child s 
 logic A fact of science for Unitarians Conclusion. 
 
 THE extraordinary circumstances under which life may 
 sometimes continue to exist has given rise to many 
 remarkable, and, in some instances, painful impressions 
 among mankind. The dormant condition of bears and 
 other animals during their winter's sleep of many months' 
 duration, and many well-authenticated instances of un- 
 usually long periods of sleep by human beings, who 
 during this condition have maintained their vitality with- 
 out food and at a very low and all but suspended rate of 
 vital action, have doubtless given rise to those popularly- 
 recited cases of asphyxia, or suspended animation, under 
 which people have been said to be buried alive, and which 
 many living individuals have a horror may be their fate 
 if left to the charge of the careless and incautious at the 
 time of death. Many have felt this apprehension so 
 oppressive that they have desired that their interment 
 should not take place after apparent death under ordinary 
 circumstances, unless in addition some violence were done 
 to the physical organization, so as to prevent the pos- 
 sibility of their coming to life again after the earth had 
 been closed in upon them ; and many have wished to do 
 
 2 E 
 
410 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 away with interment altogether to avoid suffering the 
 horror of suffocation in the tomb. This kind of death, it 
 is idle to deny, has a character of horror for the human 
 mind, the metaphysical associations of which invest it 
 with an ideal, but not on that account the less a real 
 agony, eminently beyond every other conceivable form of 
 terminating our mortality. That instances well authen- 
 ticated of people being buried alive under misapprehension 
 have occurred cannot be gainsayed, and a circumstance 
 was brought before public attention not many years ago 
 which appeared to support the idea that this was much 
 more common than was usually suspected, for it was found 
 on opening many tombs for the purposes of subsequent 
 interments in the same place that the faces of the parties 
 previously interred were generally found turned downward. 
 This was concluded to be evidence of the persons having 
 awoke in the grave after their interment, and in their 
 helpless and hopeless struggles for relief turning round 
 upon their faces, and dying under these dark circum- 
 stances in despair. Fortunately a more careful investiga- 
 tion of the facts satisfactorily dispelled this truly horrible 
 impression. It was found that, though the skull was face 
 downward, it was not until decay had so far progressed 
 as to effect separation of the vertebrae of the neck that it 
 was so, and that the rest of the skeleton still remained 
 upon its back. This fact was utterly at variance with 
 the idea of the person having become alive in the tomb 
 and afterwards dying of suffocation, because the position 
 of the face downwards, and the body on its back, was 
 impossible as a result of voluntary action which any one 
 may prove by attempting to turn the head round so as 
 to see directly behind him while retaining the breast 
 in the opposite direction ; and a little further investiga- 
 tion showed that the skull when separated by decay from 
 the neck could not balance itself on the back of the head, 
 
SUSPENDED ANIMATION. 411 
 
 but invariably turned round on the face under the law of 
 its own gravitation. But though this satisfactorily dis- 
 pelled a most painful impression, it has neither fully 
 dissipated the popular horror of being buried alive, nor 
 disproved instances in which that has actually taken 
 place ; and a general belief prevails that there are cases of 
 unusually long-suspended animation, or asphyxia, under 
 which the same thing is continually liable to be repeated. 
 That the medical profession have not been able to 
 authenticate any such cases of long-continued asphyxia, or 
 suspended animation, is however a very important fact. 
 To suspect that highly honourable profession of any 
 collusive suppression on the subject seems impossible; 
 but that the reader may fully understand the subject, and 
 place the question beyond suspicion to his own intel- 
 ligence, let him consider what the conditions of asphyxia, 
 or suspended animation, are. Now a complete cessation 
 of the pulse, and a consequently complete stoppage in the 
 circulation of the blood, which cannot proceed without 
 pulsation, are primary features of asphyxia ; and such 
 conditions have not been found capable of continuing 
 beyond a certain time without such a change taking place 
 in the stagnated blood as utterly unfits it from resuming 
 its circulation or retaining those elements of vitality 
 which are necessary to the resumption of human life. 
 The time usually allowed for this fatal change taking 
 place in the condition of the blood is that ascribed to 
 cases beyond which restoration from drowning, hanging, 
 syncope or fainting, and suffocation, have never been 
 known to take place, and is held by such experience not 
 to exceed a few hours. On this subject an eminent 
 authority, Mr. Smee, says : " Where one dies suddenly 
 without a clear equivalent cause which is irremediable, the 
 heat of the body should be maintained at least twelve hours 
 by hot bottles, and artificial respiration should be at- 
 
412 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 tempted as for drowning. Remember that the death may 
 be only apparent, and your care may be repaid by the 
 inexpressible delight of seeing life gradually resumed and 
 the party restored to his family." This excellent advice 
 cannot be too carefully adhered to, for there can be no 
 doubt that where people have been buried alive culpable 
 carelessness has had much to do with the matter. There 
 is a condition to which humanity is in extraordinary 
 instances liable, where, without absolute asphyxia or 
 complete stoppage of the circulation, the pulsation may 
 be so low that, though the person is only in a very pro- 
 found state of prolonged sleep and low vitality, the 
 evidence of circulation in the blood and consequent 
 pulsation may escape ordinary attention, and the coldness 
 of the breath, from the temperature of the body being 
 allowed by those in attendance to get too low, may not 
 even mist a mirror held before the face. This, however, 
 which is only a state of coma, will not deceive the com- 
 petent physician, who in all such cases will be able at 
 once to detect the difference between coma and asphyxia ; 
 and the danger of interment alive to the sufferer will only 
 occur where medical aid has not been called. Instances 
 of coma being produced artificially are said to be known 
 to the Hindoos, who will allow themselves to be thrown 
 into it, and even buried alive, for short periods, in 
 shallow graves, where the porousness of the earth allows 
 sufficient air to reach them for the low rate of respiration 
 which takes place while they are in that state. More 
 astonishing instances occur among some of the other 
 animals that of bears in the northern districts of Europe 
 and elsewhere, which has been already referred to, being 
 sufficiently well known. And those remarkable cases of 
 toads found in stones in the course of quarrying, and 
 other excavations of the earth's crust, where the animal 
 must to all appearance have remained imprisoned for 
 
TOADS FOUND INCLOSED IN ROCKS. 413 
 
 thousands of years, are instances of vitality supported 
 under circumstances so abnormal as to excite the utmost 
 wonder at its tenacity. Such cases are manifestly 
 not asphyxia, and can hardly be said to be even coma. 
 The toad, as is well known to naturalists, is a foul- 
 blooded animal, and does not purify its blood perfectly 
 at the lungs during circulation. It seems capable, there- 
 fore, of living under similar circumstances to those under 
 which thick-leaved plants exist in hermetically-closed 
 conservatories without renewed air or water, and is able 
 sufficiently to purify the air around it for the purposes 
 of its own respiration. It can, therefore, live in a less 
 quantity of air, and with a less degree of absolute purity 
 in the atmosphere by which it is surrounded, than would 
 be possible for a pure-blooded animal, or one which, as 
 an essential of its health, required to purify its blood 
 perfectly at the lungs. But it is well known that the 
 toad possesses remarkable powers of vitality in the earlier 
 stages of its existence, i.e., when in the tadpole state, in 
 which, with gills like a fish, it may be seen in our slow 
 running streams and stagnant pools during the period of 
 its development as a small black comet-shaped creature, 
 consisting of a round nucleus or head, and a tail. In this 
 state, if separated from the head, the tail will continue 
 to live, and even grow for many days ; while, in the mean- 
 while, the head grows a new tail for itself, repairing the 
 injury and restoring the completeness of the animal. 
 But this power of vitality in animals, as well as in plants, 
 is in many instances more remarkable than the above. 
 In plants, as is well known, propagation by slips and off- 
 shoots is easily effected, and inversion of the whole 
 direction of vitality may be accomplished, for trees and 
 shrubs capable of being propagated by cuttings seem 
 generally to possess this remarkable peculiarity that 
 either end of the cutting may be inserted into the ground 
 
414 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 or into the stock in grafting, and the cutting will reverse 
 the action of its fluids, and throw out its branches with a 
 downward, instead of an upward tendency, such as we see 
 in that plant now so much cultivated, the weeping, or 
 drooping ash, which is a tree grafted on this principle. 
 Among animals the polypes seem to possess still more 
 wonderful powers of vitality. They are tube-like forms, 
 and if turned inside out the outer coating will become a 
 stomach, and the stomach an outer skin. They can be 
 cut into pieces, and each piece will continue to live and 
 become a perfect polype. If punctured, the punctured 
 part will shoot forth a young polype, which may be cut 
 off and separated from the parent, and cut into pieces, and 
 each piece become an independent and perfect polype. The 
 annelides, or earth-worms (Lumbricidce), seem possessed of 
 similar vital energies. These worms, like the leeches, are 
 hermaphrodites (Monoicous), the one end being male and 
 the other female. If cut in two both ends will become 
 separate individuals, and will grow into perfect worms by 
 reproducing the ends of which they are deprived. Nothing 
 is more common in turning up soil than to see worms 
 with a thick and a thin end. These are worms which 
 have been severed by the spade or other cause, the thick 
 end being one of the halves of the original worm, and the 
 thin end being a reproduction of the severed part. In 
 such cases it might be said that the hermaphrodite is two 
 animals joined together, but capable of separate existence, 
 and possessed of distinct and separable vitalities ; and so 
 of plants capable of being propagated by cuttings, 
 and of polypes that they are a combination of many 
 distinct and separable vitalities, and capable, when 
 severed from each other, of self-restoring powers : the 
 plant restoring itself by reproducing the severed root, 
 and the animal by reproducing the severed member. In 
 both plant and animal the hermaphrodite peculiarity in 
 
DORMANT VITALITY. 415 
 
 such cases prevails. The animal and the plant are equally 
 capable of reproducing in the ordinary way, as well as 
 by cuttings, and the long period during which vitality may 
 be entirely dormant in plant life, as well as in some 
 animals, bears a very close analogy. In plants we have 
 the example of the mummy wheat, representing thousands 
 of years of dormant life ; but it is also found, not only 
 that seeds may be kept for many years without injury 
 to their vegetating power, but that even the pollen or 
 yellow dust from the anthers of flowers may be kept for 
 years, and afterwards used in hybridizing and in pro- 
 ducing seed. While in animal life, that of the toad, which 
 we have already referred to, might be supplemented by 
 many instances of the prolonged dormancy of eggs or 
 ova, and also by the remarkable experiments by Spallan- 
 zani, Davaine, Gavarret, and others with the Tardigrades 
 and Rotifera, or Wheel Animalcules, which it has been 
 found can be dried and moistened, or killed and revived 
 as it was at one time considered, and the experiment 
 repeated with them many times after intervals of years. 
 At one time it was supposed these animalculse could bear 
 to be perfectly desiccated, but more careful observation 
 has shown that, unless a small essential quantity of 
 moisture remains in them, replacing them in water will 
 fail to restore their vitality. Of course their vitality 
 is never actually gone, it is merely in a state of suspen- 
 sion or dormancy. 
 
 But these remarks are introduced less because they are 
 conclusions, than because they form the threshold, and 
 merely the threshold, of an exceedingly great and interest- 
 ing and, at the same time, utterly incomprehensible sub- 
 ject the great life chain of reality. Take up any link 
 of this wonderful subject and examine it carefully, and we 
 will find that, instead of being within the range of intelli- 
 gible and natural laws, we are altogether thrown out of 
 
416 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 our logic into a region for which nature has no law, but 
 which is not the less a vivid reality, most deeply and per- 
 manently concerning ourselves. We have many wonder- 
 ful statements in scientific works on the subject of matter 
 and its divisibility. It is stated, for example, that there 
 are more animals in the milt of a single codfish than 
 there are men on the whole earth, and that a single grain 
 of sand is larger than four millions of these animals. 
 But let us take a moderate estimate of this fact, far 
 within the limits of truth, and therefore free from all 
 hyperbole, for the purpose of reaching a deeper and more 
 interesting region of reality beyond it. Let us, for 
 example, content ourselves with assuming that there are 
 only ten millions of those animals in a single codfish, it 
 follows that this single codfish was but one of ten 
 millions in the milt of its progenitor, and that progenitor 
 but one of ten millions in the milt of its parent, and so 
 on backward until you reach the three-hundredth ancestor 
 in a direct line of reproduction ; and here you find the 
 fact utterly surpassing all our possible investigation into 
 its physical reality, but not the less a fact on that account, 
 that this three-hundredth ancestor must at that stage of his 
 existence when he was in the milt of his parent, and only, 
 say, a millionth part the size of a grain of sand for we 
 are speaking of the progeny in the milt, not in the roe 
 this animal in this minute condition, we say, must have 
 had within him in turn a progeny whose numbers in the 
 three-hundredth generation after him would be so nume- 
 rous that, were we to begin at the top of this page with 
 the number ten millions, we should have to add as many 
 ciphers as there is space for types in the whole page to 
 note them down. Taking the page, then, at thirty- six lines 
 of three inches long, we should have for this number a line 
 of figures, of the size of the present type, three yards long. 
 Carrying this curious calculation back to the time of Caesar 
 
DIVISIBILITY OF MATTER FACTS BEYOND PHYSICS. 417 
 
 Augustus, the product would fill six pages of this work ; 
 and if extended in a single line of figures as large as our 
 type would form a sum eighteen yards long : carried back 
 to the founding of the Chinese Empire, according to some 
 historians, it would fill thirteen of our pages, and give a 
 single line of figures thirty-nine yards long, as any of 
 our readers may satisfy himself by multiplying the first 
 ten millions by ten millions for the succeeding year, and 
 so on, and observing that each year adds seven ciphers to 
 the product. He has therefore merely to take the number 
 of years and add seven ciphers for each. And yet this 
 extraordinary result is probably as far within the mark as 
 it may at first sight appear hyperbolical and excessive, 
 for we have not merely assumed, within our limits, that 
 the cod milt contains only ten millions, instead of more 
 nearly eight or ten hundred millions, but that each fish 
 reproduces its species only once a year, and once in a life- 
 time. At the same time it is not essential to our calcula- 
 tion, or its object, that these animals do not all reach full 
 development and maturity ; it is enough for what we are 
 about to observe on the subject that they exist even for 
 only an instant at any stage of their vitality. Now we do 
 not state this for the purpose of illustrating the infinitesi- 
 mal divisibility of matter, nor the extent of its practicable 
 divisibility in the hands of its great Maker and Master ; 
 for while we freely and reverently acknowledge God's per- 
 fectly illimitable omnipotence in this as in all directions, 
 we do not believe that He lias chosen to subdivide matter to 
 this degree, and we venture to think that various chemical 
 facts are inconsistent with such a hypothesis. We think, 
 on the contrary, that we are on the verge of a new dis- 
 covery, and a discovery with which we cannot hope to 
 laurel ourselves, for it will only, we fear, reveal to us how 
 little we know how little of palpable and unchallengeable 
 fact and reality we ever here can hope to know. In editing 
 
418 ADDITIONAL PHENOMENA OF NATUEAL MAGIC. 
 
 Joyce's Scientific Dialogues for Mr, Tegg, the present 
 writer ventured, at p. 324 of that work, to say that, while 
 it was impossible to conceive of any body or particle of 
 matter so small as not to have two surfaces, the one of 
 which must be capable of physical separation from the 
 other, had we means sufficiently fine to accomplish the 
 separation, " yet there is reason to believe that the sub- 
 division of matter stops short of this infinitesimal redu- 
 cibility of parts in a definite and ultimate molecular form, 
 very minute indeed, but beyond which material elements 
 never are divided, though it is of course impossible to 
 conceive that these molecules or atoms of matter are in- 
 capable of being divided still further had we the means ; 
 only if further divided they would cease to be molecules, 
 and would only be fragments of molecules. Chemistry, 
 from the proportions in which different elements chemi- 
 cally combine, has long pointed to, and now absolutely 
 demands, this solution of the structure of matter." The 
 view above stated we find no good ground for qualifying 
 here, even in the presence of the extraordinary fact as to 
 reproduction in the codfish which has just been set forth, 
 and which is greatly exceeded in the reproductive history 
 of many other animals and in many plants. What we 
 maintain is, that the subdivision we have set forth in this 
 case of animated nature is far beyond the molecular, and 
 very, very far beyond the possible organic subdivision of 
 matter, taking nature as it is that the hundredth pro- 
 geny or descendant of a codfish has, consequently, no phy- 
 sical or organic existence whatever in its hundredth 
 ancestor or progenitor, and that its connection with its 
 ancestor during the earlier stages of that ancestor's exist- 
 ence and development is not and cannot be a physical one. 
 We do not at the same time deny that the connection 
 exists, or existed at that stage ; on the contrary, we affirm 
 that it did then exist, and was in the parent as essentially 
 
NEW FACT IN PHILOSOPHY. 419 
 
 as the parent's own life and reproductive powers were in it. 
 But then it must have been in it only in the condition of 
 life in that mysterious yet real, but utterly incompre- 
 hensible state of dormant vitality, of which nature's laws 
 which hazy philosophies make the absolute and dominant 
 rule of everything in these days can give us not the very 
 slightest knowledge, and material criteria not the vestige 
 of available measurement. 
 
 There is certainly little corroboration to be derived 
 from facts like the preceding in behalf of the ex nihilo 
 nihilfit philosophy. It is a remarkable circumstance that 
 all who have ventured to state these absolute and ultimate 
 propositions have had but a very limited knowledge of 
 scientific fact, even while claiming to be exclusively 
 scientific men. In the age in which these philosophies 
 sprang up all the science known, even had it been all com- 
 prehended in one mind, was, as compared with that of our 
 own age, limited and imperfect. Among modern philo- 
 sophers who have ventured to reproduce these propositions 
 we have never found one who had a wide and comprehen- 
 sive knowledge of comparative science who was more 
 than distinguished in some particular department within 
 which his knowledge was respectable enough and worthy 
 of being received as authority, but beyond which it* was 
 all but contemptible and feebler than that of a child, as 
 well as more erring because more confident who ever 
 could draw a wider analogy than that which his own 
 limited department of study afforded, or look upon the 
 illimitable range of general philosophy save with a mono- 
 chromatic vision coloured exclusively by the light per- 
 vading his own point of view. If all scientific knowledge 
 when these propositions were first dogmatised was in- 
 adequate as a basis for ultimate and absolute conclusions, 
 how much less can the professor distinguished by merely 
 one branch of study now be justified in rearing up his 
 
420 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 solitary testimony in behalf of them when reproduced in 
 an age like this, in which we are only beginning to feel 
 fully the littleness of achievement, the feebleness of human 
 capacity, and the inexhaustible harvest of eternal discovery 
 and expansion before us ? " Through the EVIDENCE con- 
 viction, manifestation, demonstration, EXty^oc OF THINGS 
 NOT SEEN" (for that is the apostolic and authoritative 
 meaning of Christian FAITH, which those who do not know 
 it call credulity), " we understand that the worlds were 
 framed by the word of God, so that things that are seen 
 were not made of things which do appear." How far such 
 a fact reaches through and beyond the uttermost depths 
 of present scientific achievement, even when we deal with 
 the subject of Matter only ! What, for example, do we 
 really know or explain of any portion of matter by saying, 
 in the ultimatum of scientific language, It is a primary 
 element? "What is gold made of?" a child will ask of 
 a philosopher. " Gold ! why gold is gold it is a primary 
 element, my dear it is nothing but gold :" so replies the 
 scientific sage. "Yes, but what is it made of?" insists 
 the pertinacious child ; for a child is a healthy inquirer, 
 and has not learned to be silenced with an unsatisfactory 
 answer. " What can it be made of but gold ?" says the 
 stultified philosopher ; " chemistry can reduce it into 
 nothing else gold is gold." But the child is not 
 answered. He is not yet acquainted with Mammon's 
 fluctuating, but on the whole approximately satisfactory 
 solution of its value ; he is not questioning his broker, 
 and is innocent of the ways of 'Change, so he pecks 
 another fathom deep into the wisdom of the vexed philo- 
 sopher, and spits him through his shallows with the broad 
 and startlingly assertive proposition, " But gold must be 
 made of something ;" and then, petulantly reiterative, adds, 
 " What is it made of?" The philosopher, remembering 
 when he also had such a question suggested by his own 
 
SUPERIORITY OF A CHILD'S LOGIC. 421 
 
 mind, feels that lie is on the verge of a primeval headache, 
 and seeing the vivacious child attracted by some new 
 subject, waits till his attention is fairly tackled, and 
 quietly leaves the throne of philosophy vacant. 
 
 But the child is right after all, and how clearly and 
 confidently he knows it ! Gold is made of something. It 
 has a molecular structure of some kind, apart from which 
 and its chemical ratios it would cease to be gold, 
 chemically and monetarily. Its ultimate molecule, whether 
 we are right in all we have said of its structure in 
 Joyce's Scientific Dialogues, p. 324, or not, is divisible 
 into something else could we but reach it, and its mole- 
 cular structure once divided its whole chemical ratios and 
 combinations would be destroyed. The philosopher may 
 be satisfied with the fact that gold is gold, but the unso- 
 phisticated child will reason straight up to his Maker, and 
 be satisfied with no explanation short of that which 
 satisfies all his awed and deep-felt consciousness that He 
 who could make himself could also make gold, whatever 
 lesser ultimatum science may proclaim on the basis of 
 primary and hypothetically irresoluble elements. This 
 is not quite intuition in a child, it is the honest energy of 
 unvitiated dialectics penetrating to the legitimate ulti- 
 matum of all causation : the only possible source of those 
 things not seen which the apostle and our own experience 
 alike demonstrate to us have their evidence in the meta- 
 physical existence and consciousness of us all. The child 
 knows he has been but recently brought into existence 
 himself, and by a competent Power which he perctives by 
 analogy to be competent to bring anything else into ex- 
 istence. In mathematical language, the first of these facts 
 is an axiom, the second is its corollary ; and both, if not 
 explanatory, are at least irresistibly convincing. But the 
 proposition that gold is self-existent is a hypothesis not 
 based on any axiomatic premise. Gold, we know, has a 
 
422 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 structure which we find can be chemically acted on. 
 But structure implies construction, and therefore gold 
 must have been constructed. We also know that self- 
 existence must reside, not in the thing constructed, but in 
 the primary constructor ; anpT thus wejinalytically prove 
 the superiority of a child's logic over that of a philosopher. 
 It may be asked, why does man as he grows up lose this 
 originally high and clear reasoning power reaching to abso- 
 lute conclusions ? The answer is, that as man grows up 
 he acquires bias, and starts favourite theories and hypo- 
 theses within the limits of his powers. It is the unvitiated 
 candour of a child that constitutes its superiority and its 
 conclusiveness reaching to the utmost penetrable limits. 
 
 Here in a department then of distinctly demonstrable 
 and experienced scientific fact we have as it were the 
 evidence that from the Creator's vital energy all conscious 
 existence has been produced, in that He has conferred upon 
 vitality a reproductive power which would be almost as 
 wonderful as his own, were it, like his, exerted by an 
 absolute, conscious, and fully enlightened volition. 
 
 What a marvellous essence then is this intrinsic element 
 of us all called life ! An element whose association with 
 physical nature is merely factitious, not inherent which 
 requires no physical space for its accommodation, and 
 does not disturb the quiescence, nor displace the juxta- 
 position or volume of matter while traversing through or 
 touching it. Matter may touch matter, and cause motion 
 or action in it ; but while life may also touch matter, and 
 by its presence endow it with vital powers, it is not, save 
 when associated with feeling, as in animals but not in 
 plants conscious of its contact with the matter in which 
 it exists, any more than a stone is conscious of contact 
 with a stone, where the contact is not the less real that 
 consciousness does not perceive it. Life may indeed 
 cause motion in matter, but not by direct but only by 
 
CONCLUSION. 423 
 
 secondary agency it must use matter to act on matter. 
 We may place the hand on an object, and vainly by force 
 of will endeavour, because our vital power is placed in 
 simple contact with it, to make that object move. We 
 must use the physical power of the hand to compel the 
 motion we require ; so that the will, without the physical 
 agency, is practically nothing. But in such a case as the 
 reproduction of animal forms which has just been referred 
 to, how divisible must this vital principle Life be, which 
 yet itself requires no physical space to contain it ! The 
 divisibility of matter is a fact obvious and apparent, but 
 this divisibility of life, associated as it is in man with an 
 equally extensive and incomprehensible divisibility of 
 mind and feeling, is a metaphysical phenomenon in- 
 herently all that importantly and essentially constitutes 
 ourselves before which the facts of natural magic within 
 their physical limits dwarf into insignificance, and which 
 makes us, even in this life, denizens of a reality wholly 
 beyond their range. 
 
 The philosophers of fixity would tell us that two and 
 two cannot make any other number than four ; that it 
 is impossible they can make any other number even with 
 God, and that Omnipotence itself has here a limit. How 
 would such theorists of the abstract-absolute explain that 
 demonstration of Omnipotence in the concrete, by which 
 life in the Polypes and Annelides is capable of being 
 subdivided from one life into many distinct and inde- 
 pendent lives ? Even accepting the theory that a polype 
 may be a combination of many lives in one, this explana- 
 tion, if it could be substantiated in that case, would not 
 apply to a worm to the same extent. For even assuming 
 that a worm as a hermaphrodite is a duplex animal, or 
 two animals in one, that fact would not explain how by 
 being cut in halves it became two such duplex animals 
 instead of one, or four animals instead of two. We can 
 
424 ADDITIONAL PHENOMENA OF NATURAL MAGIC. 
 
 understand the separation of the material part or body of 
 the animal, for the matter of the one is not the matter 
 of the other, but we cannot so easily understand the 
 division of one life into two lives, or two lives into four, 
 for that is changing an identity into more than .one. 
 Perhaps the Unitarians, who have so long denied the 
 existence of the Trinity, on the ground of its absolute 
 impossibility, will aid us with their logical taper here. 
 
 Some of our readers will possibly think the argumentum 
 ad hominem might be applied to us on this subject, on the 
 ground of what we have said ourselves in a preceding 
 page as to the fixity of truth, but it must be borne in 
 mind that we have never with the inherent consciousness 
 of our own purely contingent and dependent existence 
 ventured to assert, or been able to find any ground for 
 asserting, the essential fixity and unchangeableness of 
 anything, as being positive, eternal, or superior to Omnipo- 
 tence, and we have nowhere found science able to de- 
 monstrate anything of the kind. Manifestly nothing is 
 absolutely fixed m this life but by the choice of Omnipo- 
 tence, and only during the pleasure of that Great Power ; 
 and scientific men may ridicule miracles, and talk of 
 impossibility as they will, while they cannot demonstrate 
 to themselves, or to any one else, the primary law of their 
 own existence, or the permanency of it, or that what is 
 what they are most sure about, viz., their own lives may 
 not cease to be. If this, then, be all the certainty of 
 what men are most sure of, what becomes of other realities 
 on the argument of analogy ? Change is everywhere, and 
 something more than change- in the mysterious region of 
 vitality creation and extinction, increase and diminution, 
 numerical as well as quantitative, are everywhere. 
 
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