M 
 
THE 
 
 PHILOSOPHY OF NATUEE 
 
lONDOIC 
 
 PBIffTED BY SPOTIISWOODB AND CO. 
 NEW-STBEET BQUABB 
 
THE 
 
 PHILOSOPHY OF NATUEE 
 
 A SYSTEMATIC TREATISE 
 
 ON THE 
 
 CAUSES AND LAWS OF NATURAL PHENOMENA 
 
 HENRY S, BOASE, M,D. F.R.8, & G.8, &c, 
 ^ 
 
 Honorary Member of the Royal Geological Society of Cornwall 
 
 LONDON 
 LONGMAN, GEEEN, LONGMAN, AND EOBEETS 
 
 I860 
 
PREFACE. 
 
 IN the following pages speculation enters more 
 largely than usual into the treatment of the 
 sciences ; and on this account may be repugnant 
 to many, as being too metaphysical. This work, 
 however, is not metaphysical, that is, mystical and 
 visionary, in the ordinary bad sense of the term : 
 on the contrary, it rests solely on the knowledge of 
 natural phenomena. In it the physical sciences 
 are referred to the fundamental principles of 
 realities ; and not only so, but even the abstract 
 sciences, which are commonly ascribed to the a 
 priori ideas of intellectual intuition, are based on 
 the direct interpretation of the rational forms of 
 nature. Whatever may be the merits of this 
 work, it is not a hasty and thoughtless production, 
 but the result of many years' diligent study, during 
 which it was, step by step, slowly completed after 
 several successive failures. 
 
 In his earnest search after truth, the author has 
 
 A 4 
 
VI PREFACE. 
 
 not hesitated to express his opinions freely, 
 whether heterodox or not, whenever they have 
 been arrived at by legitimate inferences from facts : 
 and as his opinions are often at variance with the 
 highest authorities, they can but have the appear- 
 ance of an arrogated wisdom, unfavourable to a 
 candid and patient consideration. So far the result 
 of his labours is unhappy : but. if, as he would fain 
 hope, some truths have been disclosed, though not 
 the whole truth, his work may for awhile be mis- 
 apprehended, but will ultimately be duly appre- 
 ciated. There is this justification for the expression 
 of so firm a conviction of the truth of his conclu- 
 sions ; that the differences of opinion have sprung 
 up, in unexpected quarters, as verifications of the 
 fundamental principle of his system : and such 
 suggestions are the surest and best characteristics 
 of what Comte calls a homogeneous doctrine. 
 
 A work, like the present one, embracing the 
 whole field of scientific knowledge, and venturing 
 on speculations, which in this country have en- 
 gaged but little attention, must necessarily contain 
 many errors ; let these be detected and corrected, 
 and a step in advance will be secured : there must 
 needs be many tentative hypotheses before that 
 happy guess be made which shall co-ordinate all 
 our knowledge into a perfect system. 
 
 The cultivators of science are still engaged in 
 
PREFACE. Vll 
 
 accumulating physical facts, according to the in- 
 ductive method, as recommended by Bacon; and 
 for the most part rest content with recording the 
 facts which they have thus discovered by observa- 
 tion and experimental research. This is an impor- 
 tant and indispensable preliminary toward the 
 construction of science : but this is not all that is 
 requisite, it is only the means to an end ; and this 
 end, for its accomplishment, requires the interposi- 
 tion of another factor, the logical intellect. So 
 that the facts having been acquired, it is competent 
 for others than their discoverers to generalise 
 them and to determine the relations of this gene- 
 ralisation to another of a higher order : what it 
 is desired to maintain is, that it does not follow 
 that a discoverer of facts and one who is well 
 acquainted with his special science, is alone quali- 
 fied for theorising; that in this case, as in most 
 affairs of life, the work is best performed when 
 there is a division of labour. The philosopher, 
 for instance, whose occupation is purely intellec- 
 tual, and who contemplates the analogies of all 
 kinds of knowledge, is much better qualified for 
 the task of colligation and generalisation. 
 
 All this, however, is well understood, and stands 
 on record. " It must never be forgotten," says 
 Sir John Herschel, "that it is principles, not pheno- 
 mena, the interpretation, not the mere knowledge 
 
Vlil PREFACE. 
 
 of facts, which are the objects of scientific in- 
 quiry." And so Comte observes, " that facts do 
 not constitute science, though they are its founda- 
 tion and material ; science consists in the systema- 
 tising of facts under established general laws." 
 Other authors might be quoted to the same purpose : 
 but this, as has been said, is well known ; and yet, 
 being known, it is virtually ignored. 
 
 There is, however, a growing conviction that 
 theories, not facts, are the great desiderata of modern 
 science : the tide is now turning in an opposite 
 direction, and the day may not be far distant, when 
 the method of deduction, that of the ancients, will 
 be more honoured than her twin sister induction, 
 which has so long enjoyed the pre-eminence. Our 
 knowledge will then be " transplanted out of the 
 external into the intellectual world ; and we shall 
 be enabled to push a priori reasoning to the utmost 
 limit of particularity, resulting in the form of indi- 
 vidual facts, of which we might have had no know- 
 ledge from immediate experience ; and thus we are 
 not only furnished with the explanation of all known 
 facts, but with the actual discovery of such as were 
 before unknown" These are not the sentiments 
 of a dreaming metaphysician, but of a philosopher ; 
 and of one too, who is deeply versed in the physical 
 sciences, and whose soundness of judgment is gen- 
 erally acknowledged. 
 
PREFACE. ix 
 
 Philosophy is the subject of the following pages, 
 and it may be well to state here the sense in which 
 this term is understood. Philosophy is the science 
 of the sciences, the summum genus of systematic 
 knowledge ; a synthesis of the diversity into 
 unity ; the universal from which by analysis all 
 particulars may be developed and demonstrated. 
 It is the pole-star of knowledge on which the eye 
 of science should ever be fixed in all its wander- 
 ings ; and which alone can ultimately guide man 
 to the attainment of the ardently desired object 
 of his curiosity, a knowledge of the Reason in 
 Nature. 
 
 If this be a correct statement of the case, such 
 a prima philosophia cannot surely be regarded as 
 mythical metaphysics. The sages of ancient 
 Greece believed in the possibility of such a philo- 
 sophy, and delighted in a Pisgah view of this tran- 
 scendent object : and day by day it is becoming 
 more and more evident, that their intellectual 
 vision was not a delusion, but the logical anticipa- 
 tion of a glorious truth. 
 
 Claverhouse near Dundee: July 1860. 
 
CONTENTS, 
 
 y CHAPTER I. 
 
 INTRODUCTORY REMARKS ON THE SYSTEMS OF PHILOSOPHY. 
 
 State of Knowledge unsatisfactory. What is Science? The Noun- 
 Substantive and logical Universal of Science. A universal System 
 of Knowledge the great Desideratum. The fundamental Principles 
 of Philosophy. Ancient and modern Systems of Philosophy. 
 Idealism and Realism ; the Necessity of their Union. Absolutism 
 of Germany. Positivism of Comte. The Identity of Physical 
 Forces : must end in Dynamism. Proposed Principle of Power, 
 a Reason-directed Force. Definition of Power. Natural Bodies 
 Dualisms of Powers. Single Powers non-existent in Nature. 
 Powers vary in Degrees of Order : so can be systematised 
 Correlation denned. The Archetype of all Dualisms. How 
 single Powers are manifested, The Relations in Dualisms for- 
 mulated. Powers are verce causes. Remarks on Causation. 
 Conclusion .... . Page 1 
 
 CHAP. II. 
 
 r ' 
 THE MINIMA AND MAXIMA OF MATTER, TH^ ATOMS OF MATTER, AND 
 
 THE CELESTIAL ORBS, ARE ALL DUALISMS OF PHYSICAL POWERS. 
 
 The System of Nature. Every Universal a Maximum, but not an 
 infinite quantity. Physical Substance or Matter the content of all 
 Bodies. What is Matter ? a Dualism of Attraction and Repul- 
 sion. Ether the physical content of Space is pure Matter. The 
 Universe originally a Sphere of Ether. Its attractive and repul- 
 sive Powers manifested as Centripetal and Centrifugal Forces. 
 Gravity and Centrifugy, correlative Forces, co-existent, but inde- 
 pendent in their Antagonism. Gravity generally regarded as the 
 
Xil , CONTENTS. 
 
 Universal Force. The forces of the Universe twofold : this Dualism 
 reconciles Kepler and Newton's views concerning the causes of 
 Celestial Motions. On the Laws of Motion. On the Conservation 
 of Forces. The primaeval condition of the Solar System. Its 
 relation to the Universe. The Origin of Planets by periodical 
 Fissions. Laplace's Theory. Comte's Remarks thereon. Solar 
 System virtually but one rotating Sphere. The relative Dis- 
 tances, Masses, and Volumes of the Planets. Has the Sun ceased 
 to evolve Planets? The Nebular Ring or Photosphere of the 
 Sun. The Zodiacal Light. Comets, different kinds of Their 
 Constitution, and mode of Formation. The Eccentricity of their 
 Courses : and their liability to Changes of Form. Astronomy not 
 an Artillery problem. Conclusion . . Page 35 
 
 CHAP. III. 
 
 THB MOLECULAR FORCES, COHESION AND HEAT, MODES OR PHASES 
 OF PHYSICAL POWERS. 
 
 All Modes of Physical Forces function in some form of Motion. 
 Molecular Motions individually inappreciable : only manifested in 
 the aggregate. Molecular Attraction called Cohesion ; Molecular 
 Repulsion, expansive Force or Heat. The term Micronomy pro- 
 posed for Molecular Physics. The Solid, Liquid, and Gaseous states 
 of Matter. The nature of Latent Heat. The Spheroidal Form 
 of Boutigny, not a fourth state of Matter. Cohesion a quantitative ; 
 Heat a qualitative Force : the former fixed and definite ; the latter 
 diffuse and variable. Condensations of Gases in porous Bodies. 
 Action of a plate of Platinum. The Quantity of Heat only deter- 
 mined relatively to a given Standard. The Zero of Heat unknow- 
 able. The Conduction of Heat. Expansion. Motion of Mole- 
 cules and Motion of Mass modes of the same Phenomenon. Joule's 
 Equivalent of a Unit of Heat. Convection of Heat in Fluids. The 
 ratio of Expansion in Gases, Expansion not an invariable indica- 
 tion of an increment of Heat. Specific Heats.- Condensation 
 evolves Heat: Heat absorbed on Rarefaction. Diffusion of Liquids 
 and Gases. Osmotic Phenomena. The Sum of Latent and Sen- 
 sible Heats and Vapours, the same for all tensions. High pressure 
 Vapours Paradoxical Effect of. Caigniard De la Tour's Ex- 
 periments thereon. Molecular Attraction. Crystallisation. 
 Isomorphism, Dimorphism. Allotropy. Conclusion . 71 
 
CONTENTS. Xill 
 
 CHAP. IV. 
 
 SOUND AND LIGHT, MOLECULAR AND ETHEBIAL UNDULATIONS. 
 
 Undulations of Material Bodies. The Medium of transmitting Force. 
 The Difference between Sound-waves and Light-waves. Light not 
 related to Heat and Electricity as Modes of the same Force. What 
 is Light? Sir John Herschel's Answer to this Question. Light, 
 like all other Motions, a Composition of Forces. According to 
 Comte, Light is something sui generis : heterogeneous to Motion. 
 All Undulations are not audible and visible. Limitation of the 
 Scale of Sound and Light Perceptions. The Analogies between 
 Sound and Light. The Origin and Constitution of Sound. Its 
 various Media : that of Air immediately concerned in Hearing. 
 The Sound-wave a Dualism of Forces. The Composition of Light 
 not yet understood. The Colours of the Prismatic Spectrum. 
 Distribution of Heat-rays and of Photographic-rays in the Spectrum. 
 These two kinds of Rays arranged in an inverse Ratio. Radiant 
 Heat and Actinism the component Forces of Light- waves. Heat 
 the Cause or Primum-moUle of Light. Actinism not a chemical 
 Force, but a Mode of Physical Attraction. Conclusion Page 104 
 
 CHAP. V. 
 
 ELECTRICITY AND MAGNETISM, PHASES OF PHYSICAL POWERS, FUNC- 
 TIONING IN THE POLAR MOVEMENTS OF MATERIAL MOLECULES. 
 
 Electricity and Magnetism, cosmical or universal Forces. Elec- 
 trology the least advanced Branch of Physics. Electricity and 
 Magnetism are not the Noun- Substantives of distinct Sciences. 
 The various Modes of producing Electricity Explanation of its 
 Origin. Electricity a Mode of Physical Repulsion. Bodies not 
 always in an electrical State. Positive and negative Electricities, 
 are co-existent and co-equal. Electrical Induction, the Action of 
 contiguous Particles. The Relations of positive and negative 
 Poles to the Current. Poles only manifested when Current passes 
 through different Media. Oersted on the Relation of electrical 
 and magnetic Currents. Heat evolved during Magnetisation. A 
 Current of Magnetism lengthens the metallic Medium: that of 
 Electricity shortens it. Explanation of these Phenomena. Dia- 
 magnetism discovered by Professor Faraday: supposed to be a 
 
XIV CONTENTS. 
 
 peculiar Force. Professor Tyndal's Experiments thereon. Mag- 
 necrystallie Force : a Crystal under its Influence virtually a Magnetic 
 Needle. Galvanism; Electro-magnetism; and other Forms of Polar 
 Forces. Conclusion . . , Page 130 
 
 CHAP. VI. 
 
 CHEMICAL SUBSTANCES, DUALISMS OF PHYSICAL AND CHEMICAL 
 POWERS. 
 
 The Union of dissimilar Substances, the characteristic of Chemical 
 Action. This a kind of Attraction. Does not act indiscriminately 
 between all Bodies: but is elective. This Attractive Force called 
 Affinity. Chemical Affinity and Electricity supposed to be identical. 
 
 -This Opinion advocated by Davy, Berzelius, and Faraday. 
 Comte regards this as confounding the Auxiliary with the Pheno- 
 
 . inenon. Electricity is a diffusive, decomposing Force; Affinity a 
 condensing, combining Force : can such Opposites be identical ? 
 The mutual Convertibility of these Forces more apparent than real. 
 Various Definitions of Chemistry. Chemical Elements, their Nature. 
 The Weight and Volume of each Element specific. The Elements 
 not Multiples of Hydrogen. Predisposing Affinity. Chemical 
 Compounds all Binaries or Dualisms. Chemical Notations. The 
 Duplication of Atoms an important Innovation. Allotropy. This 
 State of Elements not permanent. Duplication of Atoms re- 
 markably indestructible. The Hydrocarbons, basic or neutral, 
 electro-negative and electro-positive ; their Combinations as quasi- 
 elements, like Cyanogen. The typal and basic Combinations of 
 Nitrogen. Conclusion . . . . .153 
 
 CHAP. VII. 
 
 ORGANISMS, DUALISMS OF CHEMICAL AND VITAL POWERS. 
 
 Life or Vital Principle the efficient Cause of Organic Phenomena. 
 Opinions concerning this Force. The most recent that of Dr. 
 Carpenter. This Opinion evades one Difficulty by creating another 
 equally insoluble. All Forces said to be one and the same, 
 mutually convertible. Life is transformed Heat. The specialty 
 of the material Substratum alone determines the Character of the 
 Force. Whence then this Specialty? The organic Germ is 
 itself a living Organism ; Heat cherishes Life, but does not impart 
 it. Difference between chemical and organic Dualisms. The Re- 
 
CONTENTS. XV 
 
 lation of specific Vital Forces to universal Physical Forces. 
 Death, the Dissolution of the Organic Dualism. Life not the im- 
 mediate Producer of Motion It makes Physical Forces sub- 
 servient to this Purpose. Life is a directing, superintending 
 Energy. It functions in acquiring, appropriating, and utilising 
 other Forces, both physical and chemical. Dr. Carus on the Nature 
 of Life. Vital Force a final Cause: so in a sense are all other 
 Forces. The Development of Organisms. The vegetative Func- 
 tions of animated Creatures Reducible to simple Principles. 
 Vegetables the intermediate Link between Minerals and Animals. 
 Animals distinguished by the Attribute of Sensibility. The 
 Nervous and Muscular Systems of Animals. Instinct and Know- 
 ledge. On the Transmutation of Species. Conclusion. Page 182 
 
 CHAP. VIII. 
 
 MIND, OR CONSCIOUS POWER, THE HIGHEST PHASE OF VITALITY. 
 
 Mind and Matter not heterogeneous. Mind differs from the other 
 Parts of the Organism only in Degree. The mutual Dependence of 
 Mind and Body. The Phenomena of Mind the Subject of Psy- 
 chology. Brutes have Minds. The Infant Mind, as regards Ex- 
 perience^ tabula rasa. Primary Knowledge intuitive. Evidence 
 of the Senses reliable : Inferences deceptive. Sensation and Per- 
 ception. Abstraction, or Mental Analysis of Knowledge. Ex- 
 perience, acquired Knowledge : communicable by Example, as well 
 as by Precept. Memory. The Subjective and Objective Factors 
 of Knowledge. Intuitive Understanding, or Common Sense. 
 Perfect Knowledge analogous to Instinct. ~A posteriori and 
 a priori Ideas. Conceptions or Abstract Ideas Their Denomi- 
 nation ; Colligation; and Generalisation. The Moral Sentiments, 
 like Perceptions, are the intuitive Data of a higher Knowledge. 
 Brutes have moral and social Intuitions, or Instincts, as well as 
 Man. Man, in relation to the Morality of Brutes, stands in loco 
 Dei. The Nature of the Will or Conscious Power. The Science 
 of Morality or Ethics. Conclusion . - TT .- . 216 
 
 CHAP. IX. 
 
 THE IDEAL SIDE OF NATURAL POWERS MANIFESTED AS FORMAL KNOW- 
 LEDGE : THE LOGICAL INTERPRETATION OF THE REASON IN NATURE. 
 
 The rational Forms of Nature give the fundamental Principles of the 
 abstract Sciences. System, or the classified Order of Degrees, the 
 most abstract Idea of Nature. The Knowledge of such a System 
 
XVI CONTENTS. 
 
 is Science or Logic. All the Sciences are based on the Principles 
 of Logic. The Definitions of Logic. Aristotle's Dictum unjustly 
 denounced. Logic relates only to the Forms of Things, and not to 
 Things themselves. Logic, like all Sciences, formed by Induc- 
 tion ; and functions by Deduction. The Character of Genus and 
 Species. Universals and Particulars. Extension and Intension. 
 A Proposition ; and its Terms, the Subject and Predicate. The 
 various Kinds of Propositions. The Syllogism. Its three Proposi- 
 tions, the Major Premiss, the Minor Premiss, and the Conclusion. 
 The cardinal Propositions ; how symbolised. The Quantification of 
 the Predicate. The Formulae of Logic. Application of Algebraic 
 Notations to Logic.~That of Professor Boole not satisfactory, but 
 his Suggestion important. Conclusion . . Page 248 
 
 CHAP. X. 
 
 TELE FORMAL SCIENCES, THE KNOWLEDGE OF IDEAL SYSTEMS. 
 
 The Mathematics Sciences of Number, Space, and Time. Regarded 
 as the Basis of all the Sciences; but this Character belongs to 
 Logic. The Early Origin of the Abstract Sciences. Arithmetic, 
 the Science or Logic of Number. Geometry, the Science or 
 Logic of Space. These Sciences might have been immediately 
 derived from Logic. What is Space ? The Real and Ideal can 
 only exist by and in each other. Space not a Vacuum, but a 
 Plenum ; the Form of the real Content gives the Idea of Space. 
 Space an indefinite Maximum, not an Infinite. The Subject of 
 Geometry is universal Extension, and all particular or subordinate 
 Parts of Extension. Of Space and Partial Spaces. What is Time ? 
 Various Conjectures thereon. No beginning and no ending of 
 Time ; but a continuous flowing onwards. All Events occur in 
 Time. Time goes on whether anything happens or not. Time 
 one of the extrinsic Relations of Existence Conceivable only as an 
 indefinite Past, Present, and Future. The Formal Succession of 
 Events gives the Idea of Time. The Analogies between Space 
 and Time. What is the Science of Time? Not Rational Me- 
 chanics, nor Rational Arithmetic ; but a special Science, Chrono- 
 metry. Conclusion . -.-, , .'-' . . 273 
 
 CHAP. XI. 
 
 THE KNOWLEDGE OF CAUSATION, THE SCIENCE OF PHENOMENAL 
 VICISSITUDES. 
 
 Introduction: On the Character of Abstract Science. Arithmetic, 
 Geometry, and Chronometry only concerned with the exterior 
 
CONTENTS. XVll 
 
 Forms of Things : but variable Phenomena depend on the inner 
 Constitution of Things. Causes must be searched for below the 
 Surface of Things, Rational Mechanics only treats of Motion. 
 The Science of Energetics has been proposed as more comprehensive. 
 A Science required capable of treating of all Changes, physical, 
 chemical, and vital. Rational Mechanics, a Branch of such a Science. 
 The proposed Science of Substance or Hypostatics. Substance, 
 a pure abstract Idea of Matter, its Attributes those of Quantity 
 and Quality ; a Composition of Causes, the abstract Idea of Forces. 
 Its Definitions, Postulates, and Axioms. The particular Sciences 
 related to the universal Science of Hypostatics. Cinematics, the 
 Science of Motion.* Statics and Dynamics. The Idea of Vis- 
 inertia. All Motions Compositions of moving Causes. Remarks 
 on the Laws of Motion. Combination, a Kind of Change, gives the 
 Special Science of Rational Chemistry or Chemics. Organisation, 
 another Kind of Change, gives Rational Physiology or Organics. 
 Conclusion ..... Page 295 
 
 CHAP. XII. 
 
 RECAPITULATION AND CONCLUSION. 
 
 Has the Thesis been proved that the state of Modern Science is 
 unsatisfactory ? Freedom of Discussion necessary for the Advance- 
 ment of Science. There are Sciences of Realities and Sciences of 
 Ideas ; Concrete and Formal Sciences : the Data of the Former, 
 Facts; of the Latter, Truths. A Trinity in Unity incomprehensible. 
 Dualism the Condition of Nature, of which the Mental Faculties 
 partake; and are capable, by consciousness, of apprehending. 
 Phenomenal Knowledge directly perceived as a Monism. The 
 general Character of Science, the Progression of Knowledge in 
 different Ages, analogous to individual Development. Review of 
 the various Sciences. A System of the Sciences. Conclusion 330 
 
THE 
 
 PHILOSOPHY OF NATURE, 
 
 CHAPTER I. 
 
 INTRODUCTORY REMARKS ON THE SYSTEMS OF 
 PHILOSOPHY. 
 
 State of Knowledge unsatisfactory. What is Science? The Noun- 
 Substantive and logical Universal of Science. A universal System 
 of Knowledge the great Desideratum. The fundamental Principles 
 of Philosophy. Ancient and modern Systems of Philosophy. 
 Idealism and Realism : the Necessity of their Union. Absolutism 
 of Germany. Positivism of Comte. The Identity of Physical 
 Forces : must end in Dynamism. Proposed Principle of Power, 
 a Reason-directed Force. Definition of Power. Natural Bodies 
 Dualisms of Powers. Single Powers non-existent in Nature. 
 Powers vary in Degrees of Order : so can be systematised. Cor- 
 relation defined. The Archetype of all Dualisms. How single 
 Powers are manifested, The Relations in Dualisms formulated. 
 Powers are verts causes. Remarks on Causation. Conclusion. 
 
 Is our scientific knowledge in a satisfactory condition? 
 As compared with that of the ancients, has it not lost in 
 intension) or conciseness of comprehension, what it has 
 gained in extension, or diffusiveness of detail ? 
 
 The Baconian method of interrogating nature has, 
 indeed, put us in possession of many branches of know- 
 ledge which were entirely unknown in the Greek school ; 
 
 B/ 
 
2 THE PHILOSOPHY OF NATURE. 
 
 but, with few exceptions, these branches, these inductive 
 sciences, as they are called, are mere colligations of facts, 
 scarcely deserving the name of science ; and, in truth, 
 the very expression inductive, which is assumed as a mark 
 of superior excellence, indicates an imperfect condition ; 
 that they are not yet sciences, but only in the stage of 
 construction. 
 
 It may be objected to this statement, that these sciences 
 are called inductive to imply that they have been induc- 
 tively formed by a series of verified generalisations, and 
 also in order to distinguish them from the deductive or 
 pure sciences. Such a notion, we think, has originated 
 in an inadequate apprehension of the subject for every 
 science must necessarily have been attained by the method 
 of induction. In some cases, this process may have been 
 greatly abbreviated by an acuteness of intellect, by a 
 happy guess as it is termed, in detecting the characteristic 
 attribute of the summum genus ; but in every case, be the 
 process long or short, induction is indispensable in the 
 construction of a science ; when, however, a science is 
 completed, when it is indeed a science, it is no longer 
 concerned with induction ; it deals not with generalisa- 
 tions, but with amplifications demonstrating by deduction 
 a multiplicity of previously unknown particulars. 
 
 It is on this account that we have asserted that, whiW 
 modern knowledge has been greatly extended, it has lost 
 that high standard of perfection which so conspicuously 
 marks the sciences of ancient origin. Should a second 
 advent of the " dark ages " suddenly arrest the progress 
 of knowledge, and benumb the intellect for a thousand 
 years, with what bewilderment would the mind, on re- 
 
INTRODUCTORY REMARKS. 3 
 
 covery from its torpid state, gaze on the records which 
 escaped destruction ; a vast collection of interesting, but 
 loosely connected facts, would probably be preserved ; a 
 rudis indigestaque moles, affording no clue for threading 
 the labyrinth of knowledge. It was otherwise at the 
 "revival of literature." The legacy of the ancient school 
 contained several sciences, logic, arithmetic, and geometry, 
 not fully developed indeed, but vital germs fraught with 
 all their essential principles, and capable, by cultivation, 
 of attaining more than even their present expansion, ca- 
 pable also of becoming instrumental in the acquisition of 
 knowledge. The modern school, under like circumstances, 
 would only bequeath rational mechanics, an important 
 gift, indeed, one enabling us to determine correctly the 
 value of physical phenomena, and capable of ultimately 
 leading to an apprehension of the reason in nature ; but 
 even this branch of the mathematics, as will hereafter be 
 shown, is not a universal but only a particular science. 
 Besides this, all is imperfection. Astronomy is as yet 
 only an inductive science; and acoustics and optics are 
 not as far advanced as astronomy, and all the other induc- 
 tive sciences are mere groups of facts held together by 
 various and often incongruous theories. 
 
 In the endeavour to substantiate our assumed position, 
 that modern science is not in a satisfactory condition we 
 have no desire to overstate the case. It is only requisite 
 to turn to the definitions of the several physical sciences, 
 and to observe how various and inadequate they are to 
 denote their respective subject-matter, to be convinced 
 that the present method of philosophising is as defective 
 as that of the ancients, which we have been taught scru- 
 
 B 2 
 
b THE PHILOSOPHY OF NATURE. 
 
 pulously to avoid : the one fails to attain a knowledge of 
 the genus by being involved among the differentia of the 
 species ; the other, by having too rashly attempted to gain 
 its object, per saltum t from the accidents of the species. 
 
 The reason of failure in both cases is obvious. The 
 ancients, led astray by the facility with which they had 
 obtained some fundamental principles, and had constructed 
 sciences thereon, seem to have been under the delusion 
 that the whole domain of knowledge could be taken pos- 
 session of by the same rapid advance. Not that they 
 were ignorant of the inductive method and of its impor- 
 tant functions in the generalisation of facts, for all this is 
 fully and admirably set forth in Aristotle's " Posterior 
 Analytics ; " but they also knew that there was a royal 
 road to science, if the intellect were equal to the under- 
 taking, and that a science once attained, could by deduc- 
 tion disclose vast regions of knowledge. They had proved 
 all this by experience ; and it is not, therefore, surprising 
 that they preferred the dash of intellectual assaults to the 
 sure, but slow, approaches by regular induction. And 
 why were the later attempts of the ancients disappointed ? 
 Why was their success so suddenly arrested ? The multi- 
 tude and magnitude of things are outward conditions, and 
 readily furnish to the contemplative mind the fundamental 
 ideas of their respective sciences; but the vicissitude of 
 things, the variable phenomena, depends on inner and 
 more hidden principles, which can only be arrived at by 
 long and patient investigations ; and failing in this per- 
 severance, the ancients were not qualified for the task 
 which they undertook, and therefore their attempts to 
 construct natural sciences were necessarily futile. 
 
INTRODUCTORY REMARKS. 5 
 
 Bacon clearly discerned the rock on which ancient 
 philosophy was wrecked; and he pointed out the proper 
 method for the interpretation of nature, which has been 
 followed to the present time with unabated zeal, and has 
 been rewarded with considerable success. But as deeply 
 enamoured of the method of induction, as the ancients 
 were of that of deduction, moderns have been most ex- 
 clusively absorbed in the object of their devotion ; gene- 
 ralisation has been their chief employment, and with 
 generalisation alone they seem disposed to rest contented ; 
 so much so, indeed, that some writers, even on logic, so 
 magnify the office of induction, as to make it the chief, if 
 not the sole, factor in ratiocination. Now all this is very 
 well, if generalisation be the ultimate object of science ; if 
 the never-ending search after facts, and the co-ordination 
 of such accumulated details, be all that is required of 
 science, then moderns are properly engaged in their 
 vocation ; but if generalisation be only the means to an 
 end, the method of forming science which is afterwards to 
 fructify ; then are they wasting their labour in enlarging 
 instead of concentrating knowledge. They have done 
 well in laying sure foundations for science ; but the 
 ancients were far more intellectual in discerning the true 
 character of science, though their later efforts were wrongly 
 directed. 
 
 Such is the opinion of many who have attentively 
 considered this subject; but, though this has been ex- 
 plicitly recorded, it has not hitherto led to any practical 
 results ; on the contrary, the rigid and contracted views 
 of Positivism seem to be almost generally accepted. The 
 careful study of phenomena and of the laws of their pro- 
 
 B 3 
 
6 THE PHILOSOPHY OF NATURE. 
 
 duction is not repudiated, for they are the requisite 
 preliminaries in every science; but we do think that 
 phenomena and their laws do not constitute the sum 
 total of knowledge ; that all Nature is not a mere 
 continuous sequence of phenomena, but that they are 
 severally produced by their respective causes. "We are 
 aware that Positivism, in the plenitude of its dogmatism, 
 will denounce this opinion as a relapse into myths and 
 metaphysics ; but, we believe, and it is the object of this 
 thesis to endeavour to substantiate our belief, that as 
 surely as things exist in space, and as events occur in 
 time, so certainly is every natural change the effect of a 
 definite cause. 
 
 By these introductory remarks we are desirous of in- 
 timating the point of view from which we regard the 
 present state of knowledge : and, before entering on our 
 subject, a few remarks on some other topics may serve to 
 render the following exposition more intelligible. 
 
 In the first place, as the consideration of the sciences 
 will form so large a part of our subject, it may be as well 
 to state what we understand by the word Science. We 
 do not mean the science of this, of that, or of any other 
 particular subject ; but what we wish to state is that 
 which Socrates so accurately indicated and so ably dis- 
 cussed more than two thousand years ago. What is 
 science in itself, or per se as it is termed ? Science is not 
 unfrequently regarded as identical with knowledge : it is 
 indeed knowledge, but it is something more. Knowledge 
 in itself is the pure resultant produced by the concurrence 
 of the conscious mind and of knowable organic impres- 
 sions ; just as the motion of a body is the product of a 
 
INTRODUCTORY REMARKS. 7 
 
 moving force and of a body capable of being moved : in 
 either case there is a composition of forces ; and the 
 resulting compound is in the one case motion, and in the 
 other knowledge. When knowledge is not pure and 
 simple, but in relation to something else, this knowable 
 something marks the nature of the particular knowledge : 
 now, science is the knowledge of some particular idea 
 that of System ; in short, it is the knowledge of system or 
 systematic knowledge. 
 
 We cannot at present enter into details, but in its place 
 it will be fully discussed, so must rest content in the 
 meantime with assuming that science is no other than 
 logic; and hence it is that geometry is the science or 
 logic of space, and astronomy the science or logic of 
 celestial bodies or stars. So that logic underlies every 
 particular science; inasmuch as it is the mental uni- 
 versal, in which each and all of them must be contained. 
 And thus it comes to pass that every science enjoys in 
 common the methods of logic ; that of induction in its 
 formation and classification, and that of deduction in its 
 demonstrative developments ; and, corresponding thereto, 
 each science, though essentially one in the indissoluble 
 unity of its antithetic methods, may be viewed under a 
 twofold aspect which divides it into its natural history 
 and physical branches; or, as we would prefer calling 
 them, the phenomenal and casual branches of the science. 
 The one view presents the subject-matter in a statical 
 state, as a synthetic whole or system; the other as a 
 whole analysed into its component parts by dynamical 
 operations. 
 
 Every science, therefore, has its noun-substantive or 
 
 B 4 
 
8 THE PHILOSOPHY OF NATURE. 
 
 fundamental idea ; and this must be regarded as a logical 
 universal. A universal which cannot be either an infinite 
 or an absolute (that is in a metaphysical sense as an un- 
 conditioned), for such are unknowable, and can, therefore, 
 form no part of knowledge. But such a universal is a 
 summum genus, the equivalent of all its subordinate 
 genera and species; just as a whole is equal to all its 
 parts. This is the limitation of natural knowledge ; all 
 particulars must be related to each other ; and these in 
 turn must be related to their universal ; and the bond of 
 union in each science is its noun-substantive, which is 
 possessed in common by the universal and all its parti- 
 culars; the latter having in addition thereto some 
 differential characteristics. 
 
 If this statement be correct, not only each science but 
 each of its subordinate generalisations is a distinct uni- 
 versal, for each universal is a diversity in unity ; and if 
 so does it not follow that all the sciences may, in like 
 manner, be united into one supreme system or hierarchy ? 
 On such a plan, we think that a system of the sciences 
 may be ultimately accomplished ; but on the principle of 
 an absolute unity all attempts have hitherto failed, and 
 must fail, for the principle is impracticable. 
 
 Whether a universal system of knowledge be possible 
 or not, it is a fact that from the earliest dawn of the 
 intellect to the present time, it has been the great 
 desideratum of philosophy. The importance of such an 
 object, could it be accomplished, has till of late been very 
 generally admitted; and to deny it is, we conceive, to 
 ignore the utility of science altogether. We know that 
 the individual sciences are of great intrinsic value, and 
 
INTRODUCTORY REMARKS. 9 
 
 just as oriental pearls, when artistically strung together, 
 according to some beautiful design, have a value far 
 exceeding the aggregate of its individual parts, so a unity 
 of knowledge would have a peculiar value of its own 
 over and above that of the special sciences of which it is 
 composed. The sciences would no longer be independent 
 and insulated, but their filiations toward each other would 
 be known ; and this circumstance alone would bring out 
 more clearly the character of each science ; by which its 
 definition, and the precise limits of its domain, would be 
 better understood ; and each science, aided by a wider 
 field of analogies, could be more successfully cultivated. 
 
 Impressed with a deep conviction of the importance of 
 such a system of the sciences, this subject has occupied 
 our attention for the last seven years; during which 
 time three hypotheses have been successively worked out, 
 until they were found inadequate to sustain the required 
 superstructure. In each instance, however, the source of 
 error was detected ; and, although each trial proved un- 
 successful, yet each was an advance on its predecessor 
 toward attaining a higher principle of generalisation. 
 During the past year, the solution of this problem has 
 been attempted by a fourth method ; and the result seems 
 to be worthy of attention. 
 
 The principle of the proposed system is that of the 
 fundamental idea of POWER ; which is not to be conceived 
 of as a mere efficiency, but as a reason-directed force: 
 a power which is a law unto itself. The real content 
 of such a power is its principle of activity or force ; the 
 ideal form of the same, is its reason, whether intuitive or 
 conscious, according to which the force functions ; whilst 
 
10 THE PHILOSOPHY OF NATURE. 
 
 the power itself is the synthesis of the real and ideal) an 
 indissoluble union, which is manifested as an essential 
 entity, or individual being. By abstraction, however, a 
 power may be regarded on either one or the other side of 
 its existence; and, according to the stand-point from 
 which it is viewed, the knowledge is said to be real, or 
 ideal. Such is the character of a power, or reason- 
 directed force. In nature there are a great many 
 powers, each differing from all others in the peculiar 
 attribute of its force, and in the special law by which the 
 operations of its force are regulated. But the grand and 
 distinguishing character of natural powers is that they are 
 always associated together in pairs or dualisms : there is 
 no such thing in nature as a single insulated power; 
 such a power can only be an unconditioned or absolute 
 being. On this twofold constitution of all natural bodies 
 physical phenomena depend; for it renders action and 
 reaction possible, without which they could not function. 
 And not only so, but in each dualism, the powers are not 
 only co-existent but also directly opposite in their attri- 
 butes ; and it is to this antagonism of forces, that the 
 conditioned character of nature must be attributed ; for 
 the constituent powers of natural bodies mutually control 
 and limit each other's energies. 
 
 In propounding this principle of power as the founda- 
 tion of a new system of knowledge, no foolish expectation 
 is entertained that we have arrived at the final truth, for 
 the whole history of philosophy forbids such a vain hope ; 
 but we trust that we may be permitted to express a hope, 
 without being charged with overweening conceit, that this 
 work, the result of long-continued and intense thought, 
 
INTRODUCTORY REMARKS. 11 
 
 may prove a step of advance in the right direction, one of 
 the many steps which yet remain before we can expect to 
 arrive at the attainment of a perfect philosophy. 
 
 Previous to entering on a more detailed statement 
 concerning natural powers, it may be as well to take a 
 rapid glance at some of the principal systems of philoso- 
 phy, in order to point out the character of the fundamen- 
 tal ideas by which they have been attempted, and to 
 endeavour to show, aided by our principle of power, the 
 reasons why they have failed to accomplish their purpose. 
 ff The tendency of the mind to generalise its knowledge," 
 says Sir W. Hamilton*, " leads us to anticipate in nature 
 a corresponding uniformity, and as this anticipation is 
 found in harmony with experience, it not only affords the 
 efficient cause of philosophy, but the guiding principle of 
 its discoveries." Explain this, however, as you may ; the 
 fact is indisputable that this love of the unity of know- 
 ledge has been the ruling passion of the human intellect. 
 
 In Greece, at a very early period, strenuous efforts 
 were made to discover the ultimate principle of nature ; 
 and, as might have been expected, researches were first 
 directed to the external, or phenomenal, aspect of bodies. 
 From this objective point of view each of the four ele- 
 ments (earth, water, air and fire), were successively as- 
 sayed, and were lastly abandoned for more subtile and 
 abstract principles, which finally led to the adoption of the 
 subjective stand-point, to which we owe many interesting 
 speculations; but above all that of the divine idea, the 
 transcendent conjecture of Plato. Thus, even at this 
 
 * Lectures on Metaphysics. Lect. iv. vol. i. p. 69. 
 
12 THE PHILOSOPHY OF NATURE. 
 
 early period, we find philosophy vibrating between the 
 two extreme doctrines of realism and idealism, and during 
 the whole of its course it has never ceased to do so, even 
 down to the present time. This is a fact of great signifi- 
 cance ; it is a standing evidence in favour of the truth, 
 that being is essentially twofold in its entity. The mind 
 operates logically, according to its rational laws, in what- 
 ever direction its attention is engaged, and it will find a 
 portion of the truth whether it fixes its gaze on the real 
 or ideal side of being ; but if it desire the whole truth it 
 must not rest content with looking first on one side and 
 then on the other, but by a stereoscopic view, it must 
 conjoin both sides into a synthetic whole. Realism and 
 idealism are the opposite sides of knowledge, just as in- 
 duction and deduction are the antithetic, but inseparable 
 methods of logic ; we may by abstraction sever them and 
 investigate their respective characters, but mental func- 
 tions and mental phenomena, that is method and know- 
 ledge, can neither of them be perfect, but by the concur- 
 rence of their correlatives. 
 
 In modern times philosophy has been most energetically 
 cultivated in Germany, indeed no other country can lay 
 claim to a philosophy of its own, that is, one which has 
 any pretensions to the high standard of a universal 
 system of knowledge. In Germany idealism has been 
 carried out to its ultimate conclusion ; the absolute idea 
 having been posited as the fundamental principle, and the 
 identity of idea and being logically deduced therefrom. 
 This startling result has been regarded in this country, by 
 our matter-of-fact minds, as a reduclio ad absurdum ; and 
 very recently even the Germans themselves have arrived 
 
INTRODUCTOEY REMARKS. 13 
 
 at a similar opinion ; at all events it has not yielded the 
 fruitful harvest which a sound philosophy would have 
 doubtless afforded. Kegarding German idealism from our 
 stand-point we should condemn it as a one-sided view of 
 knowledge, and we should still more object to it because 
 its fundamental principle is not a logical universal, having 
 relation to all parts of its system. This objection respec- 
 tively applies to the doctrines of Fichte, Schelling, and 
 Hegel, for though each of these differ in many respects 
 from one another, they all agree in positing their peculiar 
 principles as absolutes, and consequently when the at- 
 tempt is made in either case to evolve therefrom relative 
 existences, the whole subject falls into inextricable confu- 
 sion. But we need not insist on this ; for Sir W. Hamil- 
 ton has unanswerably demonstrated that there is a gulf be- 
 tween the conditioned and the unconditioned which cannot 
 be bridged over, and that all attempts to do so, must end 
 in nihilism. In thus freely expressing our opinion con- 
 cerning idealism, we have no desire to undervalue the 
 intellectual labours of the Germans ; their philosophical 
 speculations are second only to those of ancient Greece, 
 and we believe that they have done more than any other 
 people toward the attainment of a system of the sciences. 
 Two other attempts at generalisation in modern times 
 require a passing notice ; the one is positivism, the other 
 the correlation or identity of physical forces. The best 
 exponent of the former is " The Positive Philosophy " of 
 Comte, In it we learn that its object is to frame a 
 hierarchy of the sciences, and to determine the invariable 
 laws to which all natural phenomena are subjected ; and 
 that " the ultimate perfection of such a system would be to 
 
14 THE PHILOSOPHY OP NATURE. 
 
 represent all phenomena as the particular aspects of a 
 single general fact, such as that of gravitation." 
 
 Now such a perfection, could it be accomplished, would 
 be a species of absolute realism. Gravitation is a uni- 
 versal force, consequently it actuates not only masses 
 but also the very atoms or ultimate particles of matter. 
 Under certain conditions gravitation can be manifested by 
 the weight of bodies, or as cohesion or crystallic force ; 
 but these and other phases of attraction, which might be 
 mentioned, do not comprise all known forces. Gravitation 
 cannot by any ingenuity be converted into, or become 
 identical with, the directly opposite forces of heat and 
 electricity, which in common with their homologue centri- 
 fugal force, always tend from and not toward the common 
 centre, as in the case of gravitation. 
 
 No wonder that Comte when he reflected on this in- 
 congruity of natural phenomena, was impressed with the 
 hopeless prospect of achieving the perfection of positivism. 
 " There is something chimerical," he says*, " in attempts 
 at universal explanation by a single law, for our intellec- 
 tual resources are too narrow, and the universe is too 
 complex, to leave any hope that it will ever be within our 
 power to carry scientific perfection to its last degree of 
 simplicity." This confession is sufficient for our purpose, 
 for it shows that the object of our inquiry is not to be 
 sought for in positivism. It would, however, have been 
 more satisfactory if Comte had not attributed his failure 
 to the imperfection of the intellect, but to the inadequacy 
 of the idea on which he had fixed to sustain his philo- 
 
 * Comte's Positive Philosophy, vol. i. p. 16. 
 
INTRODUCTORY REMARKS. 15 
 
 sophy. He begins well with the categorical statement, 
 that his system ought to rest on a single general principle, 
 and when he found that this was impracticable he should 
 have acknowledged his error and not blamed the mental 
 capacity ; but he even goes farther yet, he decries the per- 
 fection of philosophy, and says that " the value of such an 
 attainment, if possible, is greatly overrated," which ludi- 
 crously reminds one of the fable of the fox and the grapes. 
 
 It only now remains to ascertain whether the opinion, 
 very current at the present day, concerning the oneness 
 or identity of physical forces, is capable of solving this 
 problem of philosophy. In the " Correlation of the 
 Physical Forces," Grove says* : " The position which I 
 seek to establish is, that the various affections of matter 
 which constitute the main objects of experimental physics, 
 (viz. heat, light, electricity, magnetism, chemical affinity, 
 and motion), are all correlative, or have reciprocal de- 
 pendence. That neither taken abstractedly can be said 
 to be the essential cause of the others, but that either 
 may produce, or be convertible into, any of the others : 
 thus, heat may mediately or immediately produce elec- 
 tricity, electricity may produce heat ; and so of the rest, 
 each merging itself as the force it produces becomes 
 developed. The same must hold good of other forces ; 
 it being an irresistible inference from observed pheno- 
 mena, that a force cannot originate otherwise than by 
 devolution from some pre-existing force." 
 
 It is indisputably true, that some natural forces are 
 only modes or phases of some one distinct and universal 
 
 * At p. 15. 
 
16 THE PHILOSOPHY OF NATURE. 
 
 force ; and such forces are mutually convertible according 
 to the conditions under which they are manifested by 
 their corresponding phenomena : but that all natural 
 forces are indiscriminately capable of being reciprocally 
 changed into each other, is, we conceive, not only con- 
 trary to facts, but is inconsistent with that action and 
 reaction which pervades nature, and is the basis of all 
 physical phenomena. In the artillery problem, for in- 
 stance, could it be said that the force by which the 
 projectile is propelled, contrary to gravity, is the same 
 as that force which continually tends to draw it back 
 again to the earth ; or that cohesion and heat, on which the 
 states of matter depend, and which act in opposite direc- 
 tions, are modes of one and the same force, and mutually 
 convertible. Is it not more reasonable to suppose that 
 in these and similar cases the forces concerned are co- 
 existent and opposite, that is, that they are correlatives ? 
 And if so, it is quite inconsistent with the very idea of 
 correlation to conceive that its correlatives are identical 
 and capable of reciprocal transmutation. There is great 
 confusion of thought in the whole treatment of this 
 subject, as is evidenced by the fact of grouping motion 
 among the single forces; for it is well understood that 
 motion is a composition of co-existent motions, the ex- 
 istence of a single motion is purely hypothetical. In 
 truth, a motion is not a reality, but only the abstract 
 idea of a body in motion : the resultant of moving and 
 resisting forces, acting and reacting on each other in 
 different directions. 
 
 One and the same kind of force can only act with 
 greater or less intensity in one direction : it is not 
 
INTRODUCTORY REMARKS. 17 
 
 possible that a force can act and re-act on itself. And 
 if the idea of the identity of all forces be legitimately 
 carried out to its ultimate conclusion, it must necessarily 
 land in a pure, simple, and absolute force. And such a 
 result would be analogous to the absolute idea in which 
 German philosophy was involved : the aspects of these 
 absolutes are indeed different, for one is an idealism, and 
 the other a dynamism ; but they are both inconsistent 
 with the twofold constitution of nature, and cannot but 
 lead to the same barren results. 
 
 Such, in a few words, are our objections to the principles 
 of former philosophies: and we now proceed to set forth 
 power^ as already defined, as the fundamental principle 
 of a universal system. 
 
 Power is Being : this is an identical proposition, the 
 simplest form of enunciating knowledge. Either term, 
 taken alone, does not constitute a thought; the term 
 being is that which is, or exists ; but what is the that ? 
 It must be a something, a reality; and when we say 
 that it is a power, the mind rests satisfied, though both 
 ideas are the purest abstractions. But immediately the 
 suggestion arises, what is a power? and its definition 
 answers, that it is a reason-directed force, a force which 
 acts according to its innate rational law. 
 
 Natural beings, we have already stated, are dualisms 
 of powers. We can, however, conceive of an infinite and 
 absolute power, by positing it as the negation of a natural 
 conditioned power: and by contemplating the transcen- 
 dent wisdom manifested in the operations of finite powers, 
 we may infer that such a power is omniscient, as well as 
 omnipotent. Thus far, by the light of nature, man may 
 
 c 
 
18 THE PHILOSOPHY OP NATURE. 
 
 arrive at a conception of a Supreme Power : but if he seeks 
 to know the relation which he, in common with all other 
 subordinate natural powers, bears to the supreme, he desires 
 knowledge which nature cannot impart ; he can, therefore, 
 only obtain it through some supernatural channel. Re- 
 velation has taught us that Absolute Being, the Great I 
 Am, or Deity, is such a power as we are considering ; a 
 reason-directed force, to whom all things are possible ac- 
 cording to the counsel of his will, which is the perfection 
 of wisdom. The attributes of power, whether infinite or 
 finite, must not be regarded as a compound, as force plus 
 reason ; but as an indissoluble union of these, co- existent 
 and co-equal, neither one afore or after the other. 
 These remarks have a theological bearing ; they have not, 
 however, been made with this intent, but expressly for 
 another purpose. We are about to enter on the considera- 
 tion of the dualisms of powers, and it is, therefore, neces- 
 sary before doing so, to have it clearly understood what is 
 meant by a simple, or single power : and unless we are 
 yet more explicit, it may be supposed that the one, or 
 absolute power, is about to be ^employed as the element of 
 natural dualisms, a proceeding which would terminate in an- 
 other form of pantheism, so justly abhorred in this country. 
 A single independent power, as already stated, does 
 not exist in nature, and if it did, it could not function ; 
 for, as in the case of an arithmetical unit, it cannot be 
 reduced to a lower, or raised to a higher value. Its ex- 
 istence can be conceived, but being ex hypothesi, out of all 
 relations, it must be as a force inert ; and, therefore, un- 
 knowable, for a cause can only be manifested by its effects. 
 But since natural powers are dualisms, their internal as 
 
INTRODUCTORY REMARKS. 19 
 
 well as their external relations are very various ; so that 
 it becomes possible to make a general system of such 
 dualisms, a system of nature. Now the very idea of 
 system implies a subordination of orders, according to 
 their degrees ; and, as in each dualism the rational forms 
 correspond with their co- existent efficient realities, na- 
 tural forces necessarily dominate over each other accord- 
 ing to the intension of their attributes. If, then, we 
 regard nature only on the quantitative side of its twofold 
 constitution, there is no possibility of associating it with 
 absolute power, as the universal ; but viewed on the other 
 side as a hierarchy of powers or beings, systematic know- 
 ledge, as ontology, might be admissible, subordination of 
 powers being the principle of such a system. And as 
 one star differs from another in glory, so cosmical beings 
 rise one above another in dignity, till they culminate in 
 man, whose attributes are a microcosm, comprehending 
 all others, together with its distinguishing mark of con- 
 scious reason. The natural universal is distinguished 
 from the summum genus of ontology by its conditioned or 
 finite character ; and from the collateral branch of the 
 conditioned, the angelic host, in having material instead 
 of spiritual bodies. Or, in other words, the natural and 
 supernatural are distinct branches of conditioned beings, 
 subordinate to, but not forming part of, the Absolute or 
 Supreme Being. 
 
 This association of powers according to degrees of order, 
 which in the voluntary powers is that of authority, and in 
 the involuntary that of necessity or compulsion, may not 
 be readily accepted by those who have been in the habit 
 of regarding universals only in one direction, as wholes 
 
 c 2 
 
20 THE PHILOSOPHY OF NATURE. 
 
 made up of similar parts, that is, which only differ from 
 each other in quantity ; but when comprehended in its 
 twofold character, in its intension as well as in its exten- 
 sion, it will be perceived that these are only one and the 
 same logical subject, viewed from different stand-points, 
 and are always in the exact inverse ratio towards each other. 
 What we are desirous of showing is that we are not drawing 
 on our imagination, in order to smoothe down a difficulty ; 
 but are proceeding logically in our argument by making the 
 predicate of the proposition universal, and the subject par- 
 ticular. Perhaps our meaning may be made plainer by an 
 illustration. Natural powers rise one above another in 
 their domination, each one possessing a peculiar and higher 
 attribute in addition to those of its subaltern ; and all, even 
 the highest, man, being subordinate to absolute power, 
 inasmuch as their attributes are finite and inferior : but it 
 does not follow that we must therefore conceive of these 
 powers as parts and parcels of the Absolute ; just as parts 
 are of a whole. They may be, however, related thereto 
 by degrees ; as different orders are to the head of a hier- 
 archy ; or as subjects are to the sovereign in a nation, or 
 as soldiers to their general in an army. And in each case 
 the influence of the supreme power may be said to be over 
 all, through all, and in all ; since they are all actuated by 
 the will of the supreme : but they cannot be said to be 
 actually parts thereof. So, likewise, in works of art, we 
 perceive the manual dexterity, and the genius of the artist, 
 and acknowledge them as his works; but no one for a 
 moment supposes that these works are part and parcel of 
 the artist himself. So, in like manner, natural powers 
 bear the impress, some faint similitude of the reason- 
 
INTRODUCTORY REMARKS. 21 
 
 directed force of supreme power, which forms a bond of 
 relationship on the principle of subordination or hierarchi- 
 cal order; but absolute and conditioned powers have no 
 community of substance, as in the case of a universal sub- 
 ject. This explanation, however, is offered as professedly 
 imperfect ; an attempt only to obtain a glimpse of the 
 bond of union which traverses the obscure gulf between 
 the conditioned and unconditioned : and happily for our 
 thesis this subject forms no essential part of our under- 
 taking ; natural phenomena are the objects of our inquiry, 
 and these are capable of being arranged as a system of 
 nature. 
 
 All natural bodies, whether the vast orbs of the heavens, 
 or the microscopic molecules of matter; whether brute 
 matter itself, or the most perfect organism, man ; are all, 
 without exception, regarded, according to our views, as 
 dualisms of powers. In the contemplation of nature, the 
 constituents of each dualism may be viewed, either as to 
 their real contents, as antagonistic forces, or as ideal forms ; 
 in the former case, the systematic knowledge obtained is 
 called physics or natural philosophy ; in the latter, meta- 
 physics or mental philosophy. But these modes of 
 investigating nature are equally one-sided ; obtained by a 
 mental analysis of the concrete objects, which are in- 
 tuitively known to us by perception. These objects or 
 natural beings are very various, and by a knowledge of 
 their differences are capable of being classified : and thus 
 we obtain a system of nature, the subject-matter of natural 
 history. 
 
 According to this view natural history is no other than 
 the cosmical branch of ontology ; and hence it is that the 
 
 c s 
 
22 THE PHILOSOPHY OF NATURE. 
 
 treatment of each branch of physics is preceded by a de- 
 scription and classification of the special objects of its 
 subject, as has already been pointed out. In metaphysics, 
 however, this relationship between the content and form of 
 the subject is generally denied, its subject-matter being 
 regarded as pure a priori truths, independent of all experi- 
 ence; these truths, as the forms or reason in nature, 
 certainly exist previously to their interpretation by the 
 mind ; and so does nature herself, and also the mind which 
 is a part of nature ; but we cannot conceive the possibility 
 of acquiring any systematic knowledge but through ideas 
 obtained from the system of nature itself. We speak of 
 bodies existing in space, as if this were something real and 
 independent of bodies ; and this is one of the highest a 
 priori truths ; but we shall endeavour hereafter to show 
 that space is the formal condition of nature, an abstract 
 idea derived from the dimensions of material bodies, in 
 short, the form of nature divested of its real contents. 
 
 Thus we have seen that even knowledge itself is of a 
 dualistic character, which it necessarily must be as the in- 
 terpretation of nature ; and we cannot express this more 
 simply than by the logical idea of correlation, which is a 
 dualism of correlatives. A correlation can only exist in 
 the union of its correlatives ; which are indissolubly co- 
 existent and antithetically co-efficient ; so that the occur- 
 rence of one of them necessarily implies the existence of 
 the other ; and it is impossible to conceive of either, except 
 in their relationship. For example, in the correlation 
 family, and its correlatives, parents and children, we find 
 all the terms of this statement satisfied. And so, in any 
 material substance, its correlative properties are weight 
 
INTRODUCTORY REMARKS. 23 
 
 and volume, and vary the proportions of these as you may, 
 the resulting correlation, or substance, varies accordingly. 
 What an absolute or simple power of gravity, functioning 
 as absolute density would be, or what the power of rare- 
 faction, resulting in an infinite vacuum^ would be, we can 
 form no conception, for we know these powers only in 
 their relations towards each other ; and it is. not impro- 
 bable, that their very existence depends on their mutual 
 antagonism. 
 
 We propose, then, the following as the universal arche- 
 type of all dualisms : 
 
 1st Correlative -f 2nd Correlative = Correlation, 
 which may also be symbolised by the formula 
 A + B = AB. 
 
 And since the expression of this equation is, in fact, a 
 definition or identical proposition, its conversion may be 
 effected, but such an operation communicates no additional 
 knowledge ; but if we change the plus sign, and also con- 
 vert the equation, we can then express either correlative. 
 
 Thus, AB - B = A. 
 or AB - A = B. 
 
 For instance, substitute a concrete for this abstract 
 illustration : 
 
 Body + soul = man. 
 
 Man soul = a corpse. 
 
 Man body = a disembodied spirit. 
 
 c 4 
 
24 THE PHILOSOPHY OF NATURE. 
 
 So likewise, Attraction + repulsion r= matter. 
 Matter repulsion = attraction. 
 Matter attraction = repulsion. 
 
 In the first illustration man is destroyed by either 
 analysis : in the one case we get a tangible residuum, 
 which for a while remains in the figure and fashion of a 
 man, though in reality it is only part of a man. The 
 body of a man is a concrete complicated power sub- 
 ordinated to his specific power or humanity ; and it is 
 only by the concurrence of these opposite powers that 
 man functions as a living organism ; remove the presiding 
 power, and the body falls back into its former state of 
 existence, as chemical substances. In the second illustra- 
 tion we deal with matter, the opposite extreme of natural 
 beings : the former is the highest development of natural 
 complexity, but the latter is the simplest form of a natural 
 dualism ; and we are arrived at that point, when one 
 power cannot be separated from another by an actual 
 analysis. 
 
 How then is it possible to obtain a knowledge of the 
 constituents of such a dualism ? The method is very 
 simple, resting on the principle, that as substances are 
 known by their properties, and causes by their effects, so 
 powers are known by their attributes. In the archetypal 
 formula above given, the dualism is supposed to be in a 
 state of equilibrium, its correlatives being equal ; and 
 consequently the correlation is as it were a neutral com- 
 pound, a tertium quid; not characterised by either of its 
 correlatives, but distinguished by its own peculiarity! 
 Now such is only one of the conditions which dualisms 
 are capable of assuming ; they may also exist in dynami- 
 
INTRODUCTORY REMARKS. 25 
 
 cal states. One of the correlative powers may possess 
 a greater energy than its antagonist ; that is, it may be in 
 a plus or excited state ; up to the point of equilibrium 
 the plus power is neutralised or rendered latent ; but 
 beyond this point the excess of power is an efficiency, 
 producing phenomena which partake of the character of 
 the predominant power. And thus it comes to pass that 
 this excess is virtually as if the power, to which it belongs, 
 were in a simple insulated state : it is not so in reality, 
 but it manifests its attribute distinctly and individually, 
 and thereby enables us to arrive at a knowledge of its 
 nature. 
 
 The constitution of natural bodies is very uniform in 
 one respect, one power, simple or compound, forms the 
 basis or body of the dualism, and another its species or 
 type ; it is the latter power which alters its relations to 
 the former by various accessions or diminutions of energy ; 
 it is the qualitative power, whilst the quantitative or 
 basic power remains stationary. But this difference, 
 however accomplished, frequently occurs, sometimes the 
 one, and sometimes the other power predominating in the 
 dualism; and as the relative proportions of the powers 
 vary, so do the corresponding phenomena : and it is there- 
 fore requisite that the formula should denote these 
 mutations. 
 
 The following is not perhaps a correct expression, but 
 it answers the purpose in the meantime, and may be here- 
 after rectified. Let A stand for the basic, and B for the 
 typal power, and we shall have 
 
 A + B s= AB, the dualism in a statical state. 
 
26 THE PHILOSOPHY OF NATURE. 
 
 B 2 + A = B 2 A, the dualism in a typal dynamic state. 
 A 2 -f B = A 2 B, the dualism in a basic dynamic state. 
 
 By way of further illustration, let us formulate the 
 different states of matter, assuming its composition as 
 given above ; which yet remains to be proved. 
 
 Attraction -f repulsion = matter in a liquid state. 
 2 Attraction + repulsion = matter in a solid state. 
 2 Repulsion + attraction = matter as gas or vapour. 
 
 Let us suppose that the matter which is undergoing 
 these physical changes is water ; as a chemical substance, 
 water has its peculiar constitution, but this must be dis- 
 regarded or abstracted, and it must, for the present, only 
 be viewed as a material body, actuated by physical powers. 
 These powers are peculiar phases of attraction and repul- 
 sion, adapted to the molecular movements of matter, and 
 are commonly known as cohesion and heat. 
 
 Cohesion -f heat = water. 
 2 Cohesion + heat = ice. 
 2 Heat 4- cohesion = steam. 
 
 Or take a chemical substance, and having made abstrac- 
 tion of all its physical or material properties, we have the 
 following : 
 
 Base -f acid = salt in a neutral state. 
 
 2 Base + acid = salt in a sub, or alkaline state. 
 
 2 Acid + base = salt in a super, or acidulated state. 
 
 In all these cases it is evident how much more simply 
 and perfectly the variations of composition are expressed 
 
INTRODUCTORY REMARKS.. 27 
 
 by the literal formulas ; the different position of the letters, 
 with their affix, being sufficient to denote the relative 
 condition of each constituent, and also the character of the 
 resulting compound. 
 
 In the preceding statement concerning the archetypal 
 correlation, the illustrations have been taken from the real 
 side of being ; but the same holds good when the attention 
 is turned in the opposite direction : in the one case, the 
 subject is concerning forces, but in the other, concerning 
 logical forms; the reason in nature, which being inter- 
 preted gives abstract ideas. When we say that we have 
 an idea of anything, it is an assertion that we are conscious 
 of or know it ; but that which we know is only the ideal 
 form, corresponding indeed with its correlative real, and, 
 therefore, when we know the one, the conviction is imme- 
 diate and inevitable that we know the other also; and 
 hence it is that all knowledge is correctly described as 
 being formal. 
 
 A few instances of correlation on the ideal side of being 
 may suffice : 
 
 A + B = AB. 
 
 Object -f subject = idea. 
 Subject + predicate = proposition. 
 Re- action + action = effect. 
 Resistance + force = motion. 
 
 It may have been gathered from what has been already 
 said, that powers are by us regarded as causes ; as vercB 
 causes, and not as the mere antecedents of phenomena; 
 and, therefore, before entering on the details of our system, 
 
28 THE PHILOSOPHY OF NATURE. 
 
 it may be as well to say a few words on the vexed question 
 of causation. 
 
 The prevailing opinion seems to be that cause and effect 
 are only an invariable sequence of events ; that a cause is 
 nothing more than the antecedent of the consequence ; 
 that cause and effect are convertible terms, capable of 
 becoming either one or the other by a species of vibrating 
 succession. 
 
 All, however, are not of this opinion ; two at least, and 
 they are a host in themselves, have protested against this 
 doctrine. (f Whatever attempts may have been made to 
 reason away," says Sir John Herschel*, " the connection of 
 cause and effect, and to fritter it down into the unsatis- 
 factory relation of habitual sequence, it is certain that the 
 conception of some more real and intimate connection is 
 quite as strongly impressed upon the human mind as that 
 of the existence of an external world." And the Rev. 
 W. Whewellj has also observed, "that men cannot con- 
 template phenomena without clothing them in terms of 
 some hypothesis, and will not be schooled to suppress the 
 questionings which at every moment rise up within them 
 concerning the causes of phenomena: to debar science 
 from inquiries like these, on the ground that it is her 
 business to inquire into facts, and not to speculate about 
 causes, is a curious example of that barren caution which 
 hopes for truth without daring to venture upon the quest 
 of it." 
 
 One of the most talented advocates of Hume's hypothesis 
 
 * Outlines of Astronomy, p. 264. 
 
 f Philosophy of the Inductive Sciences, vol. ii. p. 268 et seq. 
 
INTRODUCTORY REMARKS. 29 
 
 (viz. that causation is the mere fact of the invariable 
 sequence of one event called the effect after the other 
 called the cause), has at considerable length discussed 
 this subject in his " System of Logic ;" great ingenuity 
 has been employed in the adaptation of facts to this 
 doctrine, but too much after the manner of the Procrus- 
 tean method. And we are inclined to think that no little 
 confusion has arisen from using the word cause in different 
 senses, as ably pointed out in Iron's " Dissertation on Final 
 Causes." If invariable sequence can explain the relation 
 of cause and effect, then is day the cause of night, and 
 night the cause of day ; for they have this characteristic 
 in perfection, and not only so, but also its other character, 
 that of being mutually convertible, on which the hypothesis 
 places great reliance. 
 
 " The Correlation of Physical Forces " is quoted as 
 affording unanswerable arguments in favour of the doc- 
 trine of sequence and convertibility. For instance, it is 
 stated that motion produces heat (or rather the effect of 
 heat, that is, expansion), and heat occasions motion; again, 
 that heat produces chemical action, and vice versa. Now, 
 we have no hesitation in asserting that these and similar 
 statements are true, only in part, but not wholly true; 
 and even when in a measure correct, it is only a question 
 of degrees. Heat is not the cause of chemical action, but 
 only the cause of a molecular condition which is favour- 
 able to chemical action ; it is, therefore, only the occasion 
 or means of facilitating combination, whilst the action 
 itself is sui generis^ as the name chemical denotes. And 
 conversely, chemical action is not the cause of the extrica- 
 tion of heat, for it can only function in combining differ- 
 
30 THE PHILOSOPHY OF NATURE. 
 
 ent kinds of molecules ; but in the act of effecting this 
 union a condensation of molecules takes place, which is a 
 secondary result of a purely physical description, and as 
 such accompanied by the extrication of heat. Chemical 
 bodies are, in common with all other natural bodies, ma- 
 terial, and therefore have physical as well as chemical 
 properties ; but physical powers cannot produce chemical 
 effects, nor can chemical powers cause physical effects, 
 which we hope hereafter to demonstrate. And as regards 
 the other proposition it is partly true, for the cause is the 
 same in both cases but under different modes or phases* 
 Thus heat produces motion) it causes the molecules of mat- 
 ter to recede from each other, which is a change of position 
 in space or motion ; and if the aggregate expansion be me- 
 chanically applied, the multitude of individually invisible 
 motions may be concentrated into the visible motion bf a 
 mass. Thus heat does indeed produce motion, and if the 
 moving mass be subjected to friction, heat is in its turn 
 evolved, that is, the aggregate motion will again break up 
 into parts, and by "putting the molecules in motion or caus- 
 ing them to repel each other, it reassumes the phenomenon 
 of expansion from which it originated. But we say that 
 such an effect is not equivalent to the energy of the 
 original cause ; for, in each repetition of such action and 
 reaction, there is an enormous reduction in degree ; and so 
 it will be until the plus state, by a continuous progression, 
 is diffused among the surrounding bodies. 
 
 " A phenomenon," says Sir W. Hamilton *, " is this. 
 When aware of a new appearance we are unable to con- 
 
 * Discussions on Philosophy and Literature, p. 585. 
 
INTRODUCTORY REMARKS. 31 
 
 ccivc that therein has originated any new existence, and 
 are, therefore, constrained to think that what now appears 
 under a new form had previously an existence under 
 others. These others (for they are always plural) are 
 called its cause ; and a cause (or more properly causes) 
 we cannot but suppose, for a cause is simply everything 
 without which the effect would not result, and all such 
 concurring the effect cannot but result." Even a motion 
 itself is not one thing ; but it is a composition of diverse 
 motions, each of which co-exists in the compound, retain- 
 ing its independent character. This is an abstract prin- 
 ciple of rational mechanics; and if this abstraction be 
 carried up to a higher generalisation, we shall have that 
 of reaction + action = resultant or effect, a principle which 
 includes motion as well as all other kinds of abstract 
 changes, and will be found, if we mistake not, to offer a 
 solution of causation. Let us give it another cast to 
 elucidate the correlation. 
 
 Resisting body + moving body = body in motion. 
 Opposing motion + direct motion = motion. 
 Re- agent + agent = action. 
 Passive cause + active cause = effect. 
 
 We now stand face to face with our subject, without 
 any extraneous concrete ideas to distract our attention ; 
 and it is now evident that, though we speak familiarly of 
 the cause of an effect, as if it were only one, yet there are l 
 in truth two causes concerned in every effect. The reason 
 of this elliptical mode of speaking, in common use, is now 
 apparent, and it is perfectly justifiable when so understood. 
 
32 THE PHILOSOPHY OF NATURE. 
 
 The active cause is the positive or plus agent, the passive 
 cause being the negative or latent re-agent ; latent, in so 
 far that it is balanced by an equivalent part of its anta- 
 gonist, but indestructible, effectively co-existing in all its 
 entirety ; and this latent cause is, we conceive, the nexus 
 in causation, which has been so long sought for in vain, 
 and so defiantly demanded by the advocates of Hume's 
 hypothesis. 
 
 The two causes act and react on each other, and the 
 resultant or effect is a composition of causes, the character 
 of the effect depending on the relative proportion of the 
 constituent causes toward each other ; and when we 
 regard causes, not as formal abstractions, but as real 
 forces, the resulting phenomena are of a similar character. 
 In short, every phenomenon is the then existing condition 
 of natural powers, as it appears to be in its manifestation 
 to consciousness, and when the phenomenon changes, we 
 intuitively refer this change to some alteration in the 
 condition of the natural object, and look around for the 
 cause of this change. We say intuitively or instinctively, 
 for even the brute beast does so, and when it becomes 
 instinctively acquainted therewith, it has acquired know- 
 ledge for the direction of its future conduct. Man enjoys 
 also the same empirical knowledge, but he also possesses 
 a higher faculty which enables him to look below the 
 surface of things, and to strive to understand the precise 
 character of the changes, to search out their causes, and 
 also the modus operandi of these causes. And as the 
 Mantuan poet has well observed, 
 
 " Felix qui potuit rerum cognoscere causas." 
 
INTRODUCTORY REMARKS. 3 
 
 Whether we shall in any degree participate in this 
 happy lot depends on the success in establishing our 
 thesis, that all natural bodies are compounds or dualisms 
 of powers, and that powers are reason-directed forces, 
 which are a law unto themselves, the reason in Nature, 
 according to which they function in the production of 
 phenomena; and lastly, that natural powers are verce 
 causce in their subordinate sphere of operations, that is, 
 derived or delegated efficiencies in relation to absolute 
 power, the Great First Cause. 
 
 Some apology may be deemed due for occupying at- 
 tention with a subject more speculative than is usually 
 brought forward, indeed, in times past, it would have been 
 inexcusable when sufficient data had not been collected 
 for such an undertaking ; but now, theories not facts are 
 the more claimant desiderata of science ; on all sides there 
 is a growing conviction that it is high time to gather 
 together and condense our knowledge into the possible 
 compass of a life-long study. Facts must be digested and 
 assimilated by the logical intellect before science can be 
 organised: as justly observed by the President of the 
 Royal Society, in his last anniversary address ; t( In the 
 pursuit of the physical sciences, the imagination supplies 
 the hypothesis which bridges over the gulf that separates 
 the known from the unknown. It may be only a phantom, 
 it may prove to be a reality." It has also been well 
 remarked by the Rev. James M'Cosh *, that " natural 
 science itself is ever touching on the borders of meta- 
 physics, and compelling physicists to rest on certain 
 
 * The Intuitions of the Mind, Introduction, p. 7. 
 D 
 
34 THE PHILOSOPHY OF NATUKE. 
 
 fundamental convictions as to extension and force. The 
 truth is, in very proportion as material science advances 
 do thinking minds feel the need of something to go down 
 deeper and mount up higher than the senses can do. 
 Whatever the physicist may think, philosophy is an 
 underlying power, of vast importance because of mighty 
 influence. It is because it is fundamental and radical 
 that it is unseen by those who notice only what is above 
 the surface. Let us see, then, that the foundation be 
 well laid, that the root be properly planted." 
 
35 
 
 CHAP. II. 
 
 THE MINIMA AND MAXIMA OP MATTER, THE ATOMS 
 OF MATTER, AND THE CELESTIAL ORBS, ARE ALL 
 DUALISMS OF PHYSICAL POWERS. 
 
 The System of Nature. Every Universal a Maximum, but not an 
 infinite quantity. Physical Substance or Matter the content of all 
 Bodies. What is Matter? a Dualism of Attraction and Repul- 
 sion. Ether the physical content of Space is pure Matter. The 
 Universe originally a Sphere of Ether. Its attractive and repul- 
 sive Powers manifested as Centripetal and Centrifugal Forces. 
 Gravity and Centrifugy, correlative Forces, co-existent, but inde- 
 pendent in their antagonism. Gravity generally regarded as the 
 Universal Force. The forces of the Universe twofold: this Dualism 
 reconciles Kepler and Newton's views concerning the causes of 
 Celestial Motions. On the Laws of Motion. On the conservation 
 of Forces. The primaeval condition of the Solar System. Its 
 relation to the Universe. The Origin of Planets by periodical 
 Fissions. Laplace's Theory. Comte's Remarks thereon. Solar 
 System virtually but one Rotating Sphere. The relative Dis- 
 tances, Masses, and Volumes of the Planets. Has the Sun ceased 
 to evolve Planets ? The Nebular Ring or Photosphere of the 
 Sun. The Zodiacal Light. Comets, different kinds of Their 
 Constitution, and mode of Formation. The Eccentricity of their 
 Courses : and their liability to Changes of Form. Astronomy not 
 an Artillery problem. Conclusion. 
 
 WHEN we regard the universe of natural beings in its 
 oneness, we conceive of it as the system of nature, where- 
 in the various species of objects are grouped together in 
 subordinate genera, according to the order of classification. 
 
 D 2 
 
36 MATERIAL ATOMS AND MASSES. 
 
 A summum genus must have its own individual charac- 
 teristic, and, since this is a universal, all its particular 
 subalterns must partake of the same character ; conjoined, 
 however, with specific properties, on which their differen- 
 tiation depends. 
 
 Every universal is a maximum ; that is, it contains 
 every existing thing which possesses its distinguishing 
 mark: this maximum is not an infinite quantity, for all 
 that relates to nature is limited, but it is an unknown 
 quantity, and therefore indefinite. " The definite and the 
 indefinite," says Sir W. Hamilton, "are the only quan- 
 tities of which we ought to hear in logic ; " and logic is 
 the rational archetype of all the sciences. A universal, 
 therefore, is an indefinite maximum, and so its definition 
 must be assumed ; and the same holds good with the 
 minimum part into which this maximum is divided ; it can 
 only be regarded as an ultimate unit, incapable of farther 
 division, and which, being indefinite, its value cannot be 
 appreciated. Thus the maximum divisibile and the mini- 
 mum indivisibile, the two extreme terms, must be assumed 
 as data in the evolution of every science. Well has it 
 then been said that all our knowledge begins and ends 
 in ignorance ; in this life we must rest content with an 
 imperfect knowledge, corresponding with our finite and 
 temporal capacities ; but hereafter, when freed from these 
 material limitations, we may hope, as taught by revelation, 
 to know even as we are known. 
 
 What then is the universal character of Nature ? It is 
 physical substance or matter ; which is the substratum, or 
 basis of all natural bodies : to matter all bodies owe their 
 physical properties, which are manifested as physical phe- 
 
DUALISMS OF PHYSICAL POWERS. 37 
 
 nomena. There are indeed other properties besides the 
 physical, viz. the chemical, and the organic ; but these are 
 special, over and above those of matter which are common 
 to all bodies ; and which therefore must for the present be 
 set aside, or abstracted, as we have now only to deal with 
 Nature as a material universe. 
 
 Such a universe of matter is the sum total of everything 
 material, and this summum genus is an indefinite maximum, 
 divisible into innumerable parts, all of which must be 
 equal to the whole, which, however, is an unknown quan- 
 tity. And so the minimum part of matter is an indefinite, 
 but indivisible unit, but still a part, and as such, endowed 
 with all the attributes of matter, whatever they may be ; 
 in short it is a material atom, beyond which, as its name 
 implies, division cannot be carried. 
 
 But what is Matter ? It is usually regarded as an un- 
 known substratum ; the basis, or support, of the properties 
 of bodies; a something in which properties inhere, and 
 without which the existence of properties cannot be con- 
 ceived. According to such a view, matter is the ultimate 
 analysis of all things, but such an analysis is worthless, a 
 mere caput mortuum; for having no attribute of its own, 
 it cannot be an object of knowledge. Some think that it 
 is an actual reality, having extension and impenetrability ; 
 but such matter is not a substratum divested of all proper- 
 ties, but a concrete natural body. 
 
 The whole tendency of modern science points to the 
 probability that natural forces are not only the causes of 
 phenomena, but that they are, in truth, the very pheno- 
 mena themselves ; that is, that all natural bodies are com- 
 positions of forces. Boscovich long ago maintained, that 
 
 D 3 
 
38 MATERIAL ATOMS AND MASSES. 
 
 the atoms of matter are physical points, or centres of at- 
 tractive and repulsive forces ; and Newton has recorded it 
 as his opinion " that the particles of bodies are either im- 
 pelled to each other and cohere, according to regular 
 figures, or are repelled or recede from each other ; which 
 forces being unknown, philosophers have hitherto made 
 their attempts upon nature in vain." * But Newton's 
 particles were hard indestructible atoms, on which natural 
 forces acted, unknown metaphysical substrata, and not, as 
 the atoms ofBoscovich, compositions of forces. 
 
 Many object to this dynamical constitution of matter 
 " that it is inconceivable, that attraction and repulsion are 
 unthinkable, unless we first think aggregated matter, as 
 that which is attracted and repelled : to obtain the cog- 
 nition of matter on this ground, we must, by a petitio 
 principii, first think the aggregate ; the very thing to be 
 explained."! Now such an objection rests on the old notion 
 of an unknown substratum ; and argue as you may with its 
 advocates, they always return again in the endless rounds 
 of this charmed circle. There must be something, they say, 
 to be attracted and repelled ; but it is in vain to search for 
 this something, for it is unknowable : now this admission 
 ought to be a sufficient refutation. We only know things 
 by their attributes, and to imagine anything void of attri- 
 butes, pronounces it to be a nonentity ; and to conceive 
 such a condition to be requisite for the action and reaction 
 of forces is tantamount to the abnegation of the reality of 
 Nature. 
 
 * As quoted in the Philosophy of the Inductive Sciences, vol. i. 
 p. 251. 
 
 f The Ecclesiastic and Theologian. May, 1859. 
 
DUALISMS OF PHYSICAL POWERS. 39 
 
 Abstract from natural bodies all their properties, except 
 their material or physical, and there remains only weight 
 and volume, as the primary properties of matter : now we 
 know that the former depends on gravity or attraction, 
 and the latter on repulsion ; the ratio of these properties 
 toward each other may be indefinitely varied, but they can 
 never be dissevered. If a body has weight and volume, 
 what more is requisite to constitute it a material body ? 
 And if we conceive of attraction and repulsion, as an- 
 tagonistic and reason-directed forces or powers, there can 
 be no difficulty in understanding that a material atom is a 
 compound of an unit of each of these forces ; and that the 
 aggregations of such atoms form molecules and masses : and 
 the latter thus formed afford a field for the operations of 
 attraction and repulsion in any proportions, and also for 
 the action and reaction of chemical and vital powers. 
 
 At all events such a conception of matter may be provi- 
 sionally conceded ; and, in the sequel, we hope to show that 
 the assumption is not improbable. We therefore posit 
 
 Attraction -f repulsion = matter. 
 
 By attraction is understood the power of attraction, an 
 attractive force capable of operating according to an in- 
 nate rational law of action ; and by repulsion, the power 
 of repulsion, a force similarly constituted but of a directly 
 opposite character ; and, lastly, by matter is understood 
 a union of these correlative forces, a dualism which has a 
 peculiar character of its own when its constituents are 
 equal, but which partakes of that of either when one or 
 other predominates. 
 
 Such being the constitution and character of matter the 
 
 D 4 
 
40 MATERIAL ATOMS AND MASSES. 
 
 question naturally arises, where is such matter to be 
 found ? All tangible and visible bodies are material, but 
 they are something more, they are either chemical or or- 
 ganic, and although we can deprive organisms of life and 
 reduce them to chemical substances, we cannot carry the 
 actual analysis any farther by the separation of the chemi- 
 cal from the material properties ; it can only be accom- 
 plished by mental abstraction. It would, however, be 
 exceedingly interesting if we could detect in nature pure 
 uncombined matter, a dualism of the physical powers in 
 all its simplicity ; and unless we greatly err, there is such 
 a substance extensively diffused as interstellar and inter- 
 stitial ether, commonly known as the ether of space, the 
 acknowledged medium by which the radiations of light 
 and heat are accomplished. 
 
 The opinion has already been advanced by Grove that 
 this highly elastic fluid is material, that it actually pos- 
 sesses weight, though inappreciable; and he thinks that 
 ether is the vapour of chemical substances, such as might 
 emanate from the sun and its planets, forming an exten- 
 sion of their atmospheres which intermingle in space. 
 This view is very different from that which we have pro- 
 posed ; viz. that ether is pure matter or physical sub- 
 stance; and it may be objected to Grove's view, that such 
 a diffusion of vapours would transfer matter from one 
 celestial body to another, on the principle of the cryo- 
 phorus ; and that in the case of insterstitial ether such a 
 content would seriously affect the chemical constitution of 
 bodies. 
 
 According to our conception ether is matter in the state 
 of a highly elastic and permanent gas, an indissoluble 
 
DUALISMS OF PHYSICAL POWERS. 41 
 
 compound of attractive and repulsive powers ; and conse- 
 quently it must possess the universal characteristics of 
 matter, weight and volume. In this dualism attraction is 
 the quantitative or basic power, and repulsion the quali- 
 tative or typical power ; and just as a chemical compound 
 can combine with another element, so ether may become a 
 compound basic power in a more complex dualism. Thus 
 ether or pure matter, in different quantities, may impart 
 the atomic weights to the various chemical elements ; the 
 specific powers of which appropriate definite amounts of 
 etherial atoms to frame their bodies, which have definite 
 volumes as crystalline forms. The enormous condensa- 
 tions which must have accompanied such combinations 
 will enable us to explain some interesting phenomena ; and 
 we need not be surprised at the amazing energy of such 
 powers, for known chemical action has taught us that 
 gases may be liquefied and even solidified thereby, which 
 have resisted the intensest cold and extraordinary me- 
 chanical pressures. 
 
 It may seem difficult to apprehend that the highly 
 elastic fluid ether is a material substance : but since solids 
 may be so attenuated as to become inappreciable vapours, 
 it does not require a great stretch of the imagination to 
 conceive that ether may be gaseous matter ; and that such 
 a fluid, though its atoms are mutually repulsive, will, 
 when in the vicinity of masses, be coerced thereby, and 
 suffer a corresponding condensation, just as the atmo- 
 spheres of celestial bodies. Space, therefore, is not a 
 vacuum but a plenum ; and as Grove has observed, the 
 ancient aphorism, Nature abhors a vacuum, though meta- 
 phorical in expression, contains a comprehensive truth. 
 
42 MATERIAL ATOMS AND MASSES. 
 
 The immensity of space is so vast compared with the total 
 volume of celestial bodies, that ether its content, invisible 
 and subtile as it is, must possess an amount of matter by 
 no means inconsiderable in proportion to that of tangible 
 and visible bodies; but whatever may be their relative 
 proportion, these two forms of matter constitute the entire 
 material universe. 
 
 Universal matter, then, is one vast dualism of attraction 
 and repulsion, and these powers, as a whole, can suffer no 
 increase or decrease ; the conservation of natural forces 
 being a fundamental principle. But though the physical 
 powers are in this respect invariable and permanent, they 
 have the capacity of altering their relations, by unequal 
 distributions, in different parts of the common system, 
 and these mutations produce the physical phenomena of 
 Nature. 
 
 Each material atom is a unit of the central forces attrac- 
 tion and repulsion, which act and react on each other 
 according to their respective laws, the one toward, and 
 the other from, the common centre ; and this antagonism 
 causes the atom to revolve on its axis, according to the 
 law of couples. And this statement is equally applicable 
 to the entire system of matter, for it is the generic cha- 
 racter which connotes all the parts, as well as the univer- 
 sal itself. Our experience contradicts the notion of a 
 universal equilibrium; for the solar system, the part of 
 the universe with which we are best acquainted, manifests 
 a constant succession of dynamical actions. This is true, 
 but such a condition of things may, in a sense, be regarded 
 as abnormal ; it has been brought about by the inter- 
 position of specific powers, which have produced the 
 
DUALISMS OF PHYSICAL POWERS. 43 
 
 perturbations which we witness ; but in all these actions 
 and reactions there is ever a tendency to the restoration 
 of equilibrium, and it is this that occasions the regular 
 sequence of natural phenomena. 
 
 The universe of matter may have originally consisted 
 solely of ether one stupendous sphere of this highly 
 elastic fluid. And supposing this to have been the case, 
 what would have been the condition of such a sphere? 
 The universal power of attraction, the sum of all the 
 aggregated atoms, would tend toward a common centre, 
 where the whole intensity of the power would be concen- 
 trated ; and the sum of the universal power of repulsion 
 would be similarly circumstanced, but in a contrary di- 
 rection, tending from, and not toward the common centre, 
 and therefore radiating to every point of the circumference 
 of the sphere ; these forces probably flowed, and continue 
 to flow, in tangential currents, after the manner of elec- 
 tricity and magnetism, by which currents the universal 
 sphere would be maintained in a state of equable rotation. 
 The internal arrangement of such a sphere would not be 
 homogeneous throughout, but would consist of concentric 
 zones, densest toward the centre and rarest toward the 
 circumference ; that is, the greatest weight and the greatest 
 volume, being in opposite directions, corresponding with 
 the amount of attractive and repulsive forces, by which 
 these phenomena are produced ; just as all correlatives, 
 whether those of real forces or of ideal or logical forms, 
 increase in intension as they decrease in extension, and 
 vice versa, being uniformly in the inverse ratio of each other. 
 
 Attraction and repulsion, thus viewed, become the 
 universal physical powers, centripetal and centrifugal 
 
44 MATERIAL ATOMS AND MASSES. 
 
 forces, which are, therefore, only peculiar phases of at- 
 traction and repulsion. The former force is also called 
 gravity, and its action gravitation ; the latter, initiatory 
 or tangential force, but which we shall speak of as centri- 
 fugy, and its action as centrifugation. Gravity and cen- 
 trifugy, as correlatives, are necessarily co- existent, co-equal, 
 and co-efficient, at least this is the condition of these 
 forces in their totality, but they are partially subject to 
 unequal distributions ; but, however their relations may 
 be changed in this respect, they cannot be entirely severed 
 from each other, for they are indissolubly united together 
 as a dualism of natural powers. 
 
 In this case, then, we are at variance with the current 
 opinion on this subject. All treatises on astronomy con- 
 sider gravity as the universal force, the only one with 
 which we are concerned in the consideration of celestial 
 motions; the tangential force being regarded as an ini- 
 tiatory impulse, once and extrinsically imparted to each 
 celestial body, which continues to act for ever, according 
 to the first law of motion provided for this special purpose. 
 Without such an assumption, the composition of forces, 
 which orbits of revolution require, could not be accom- 
 plished ; but why the tangential force should be afterwards 
 set aside in order to maintain the autocracy of gravitation, 
 is not satisfactorily explained. And the reputed origin 
 of tangential force by the express interposition of Deity, 
 is an unworthy expedient for such a science as astronomy, 
 which ought not to be involved in such a perplexity as to 
 be driven to the Deus ex machina the last resort of 
 ignorance. 
 
 In the "History of the Inductive Sciences," it is observed 
 
DUALISMS OF PHYSICAL POWERS. 45 
 
 that " the conception of Newton, equally bold and grand, 
 disclosed between all the bodies of the universe forces of 
 the same kind as those which produce the weight of bodies 
 at the earth ; " " and it has been found that the theory of 
 universal gravitation takes up all the facts of astronomy, 
 as far as they have been hitherto ascertained." This 
 statement completely subverts our view of the subject ; it 
 is requisite, therefore, to make a few remarks thereon, in 
 order to ascertain, if possible, which is correct. 
 
 According to Newton, each particle of matter has 
 gravity ; and the weight of any mass is the sum of the 
 weight of all its particles, and the force with which two 
 bodies attract each other is directly as their mass, and 
 inversely as the square of the distance. Thanks to New- 
 ton, our knowledge of gravity is almost, if not altogether, 
 perfect; but still, as regards astronomical phenomena, it 
 is but one side of the question, it leaves us to contend 
 with centrifugy as a mere assumption. We know that 
 it is the sum of attracting units which makes up the 
 gravity or weight of a mass ; and why, then, should we 
 ignore that the volume of the mass depends in like manner 
 on its units of repulsion ? Every mass has not only 
 weight^ but volume also, and it is impossible to conceive a 
 body destitute of either of these properties. Density or 
 specific gravity is a quantity, directly as the weight and 
 inversely as the volume ; and specific volume or capacity 
 is a magnitude, directly as the volume and inversely as 
 the weight. Now if it be important in molecular physics 
 to consider not only the force which causes particles to 
 cohere, but also the correlative force which causes them 
 to expand or be driven asunder, to investigate and 
 
46 MATERIAL ATOMS AND MASSES. 
 
 acknowledge the importance of heat as well as that of 
 cohesion; why in celestial physics should attention be 
 restricted to one force, when we know that two are 
 required in every motion, since it is a composition of 
 forces ? We contend that, if gravity be recognised as a 
 universal force, centrifugy is fairly entitled to the same 
 distinction. 
 
 Now in maintaining that centrifugy is a distinct physical 
 force demanding particular consideration as much as gra- 
 vitation, in that the one is concerned as much as the 
 other in every astronomical phenomenon, we are not 
 dealing with a mere fanciful imagination, but with facts. 
 Centrifugal force is a vera causa, it enters into the com- 
 position of all celestial motions ; gravitation tends to draw 
 all the planets to the centre of the solar system ; centri- 
 fugal force counteracts this endeavour and maintains them 
 in their orbits. It has been well observed by Sir John 
 Herschel, that " that which opposes and neutralises force 
 is force ; " and it therefore follows that, since gravitation 
 is a force and treated of as a real cause, so centrifugal 
 force, as one of the factors in celestial motions, ought to 
 be dealt with in a similar manner. We are justified in 
 this conclusion by the excellent directions which the 
 above-mentioned able author has given for conducting 
 philosophical inquiries. " In framing a theory which 
 shall render a rational account of any natural phenomenon, 
 we have first to consider the agents on which it depends, 
 or the causes to which we regard it as ultimately referable. 
 These agents are not to be arbitrarily assumed, they must 
 be such as we have good inductive grounds to believe do 
 exist in nature, and do perform a part in phenomena 
 
DUALISMS OF PHYSICAL POWERS. 47 
 
 analogous to those we would render an account of, or such 
 whose presence in the actual case can be demonstrated by 
 unequivocal signs. They must be vera causce, in short, 
 which we can not only show to exist and to act, but the 
 laws of whose action we can derive independently, by 
 direct induction, from experiments purposely instituted ; 
 or, at least, make such suppositions respecting them as 
 shall not be contrary to our experience, and which will 
 remain to be verified by the coincidence of the conclusions 
 we shall deduce from them with facts." * All these re- 
 quirements are said to be satisfied in the case of gravita- 
 tion ; and if so, mutatis mutandis, the same applies to 
 centrifugal force. 
 
 If this point be conceded, it affords an interesting 
 result ; it reconciles the apparently discordant theories of 
 the two greatest astronomers, it shows that Kepler and 
 Newton were both right and both wrong inasmuch as 
 neither of them took into account both sides of the ques- 
 tion. Kepler erred in assuming that centrifugal force was 
 the energy which keeps up the motions of the planets ; and 
 Newton, in regarding the force which deflects these motions, 
 as the main object of research. " Kepler's forces," says 
 Whewell f, " were certain imaginary qualities which ap- 
 peared in the motion which bodies had ; Newton's forces 
 were causes which appeared by the change of motion. If 
 Kepler's forces were destroyed, the body would instantly 
 stop; if Newton's were annihilated, the body would go 
 on uniformly in a straight line." 
 
 This illustration will enable us to put in a clearer light 
 
 * Discourses on the Study of Natural Philosophy (209), p. 197. 
 f History of the Inductive Sciences, vol. ii. p. 19. 
 
48 MATERIAL ATOMS AND MASSES. 
 
 our notion concerning the correlative powers, gravity and 
 centrifugy. If the force of Kepler were destroyed the 
 body would lose its volume and collapse into absolute 
 density, a density void of all relations, and therefore a 
 nonentity in nature ; and if Newton's force were annihi- 
 lated the body would be reduced to a mere vacuum, void 
 of all ponderous content, and therefore incapable of motion 
 of any sort. This is self-evident, for if a body only gravi- 
 tates as the sum of its gravitating atoms, and these be 
 taken away, how can it thus function? Unless indeed 
 we return to the " beggarly element " of an unknown 
 metaphysical substratum, and regard this as the body in 
 which forces inhere, which would sadly mar the beauty of 
 Newton's theory. 
 
 But there is another argument against the supposed 
 result which would follow on the destruction of Newton's 
 force ; viz. that the body would go on uniformly in a 
 straight line. This is based on the first law of motion ; 
 but there is another law, that of Galileo, which was 
 arrived at by the investigation of facts, and does not rest, 
 like the former, on the postulated hypothesis of inertia ; 
 and according to this law every motion is a composition of 
 motions or of forces which independently co-exist in every 
 motion. How can these two laws be reconciled? The 
 one contemplates a motion arising from the operation of a 
 single force, the other says that every motion is a composi- 
 tion of forces. According to Newton's law of motion also 
 there is action and reaction in every motion. Now from 
 what has been already stated, that all natural bodies are 
 dualisms of forces, and that all, quoad their physical or 
 material part, consist of attraction and repulsion ; it fol- 
 
DUALISMS OF PHYSICAL POWERS. 49 
 
 lows from such a constitution that when these physical 
 forces function as motions, that both forces must indepen- 
 dently co-exist in each and every phenomenon ; and that 
 such phenomenon must have resulted from the action and 
 reaction of its constituent forces, and according to the 
 character of their relation so will be that of the corre- 
 sponding effect. This is the view of the case from the 
 realistic stand-point, regarding the motions as bodies 
 moved ; but dealing with motions as an abstract question, 
 as belonging to rational mechanics, the laws of motion may 
 be thus expressed. 
 
 First law. Motion is the composition of independent 
 but co-existent motions. 
 
 Second law. Motion is curvilinear, the resultant of its 
 component motions, which act and react on each other 
 from opposite directions. 
 
 Third law. Motion approximates to the rectilinear in 
 proportion as one component motion predominates over its 
 antagonist. 
 
 No natural motion can be absolutely rectilinear, for no 
 physical powers, the cause of motion, can be insulated 
 from their dualism ; therefore it can only be inferred from 
 the tendency of attraction toward a common centre, and 
 of repulsion directly therefrom, that, if either could pos- 
 sibly act alone, it would operate in a rectilinear direction. 
 In the enumeration of the laws of motion the chronologi- 
 cal order of their origin is usually followed, but we have 
 above given the preference to the logical order of their 
 evolution. 
 
 On our view of the subject gravity and centrifugy are 
 universal powers, phases or modes of the physical powers 
 
 E 
 
50 MATERIAL ATOMS AND MASSES. 
 
 attraction and repulsion ; powers which are indissolubly 
 associated together, and which exert their peculiar and 
 antagonistic forces according to their respective reason- 
 directing laws; the former acting directly as the mass 
 and inversely as the distance ; the latter, directly as the 
 distance and inversely as the mass. This antagonism, 
 ever varying in its actions and reactions, produces the 
 great diversity of motions which are manifested by the 
 celestial bodies. 
 
 This conception of a dualism of central forces will 
 render, we think, the apprehension of astronomical pheno- 
 mena more easy for the student to whom the one-sided 
 view of gravitation, as the universal force, has always 
 been a stumbling-block; to the man of science it may 
 be superfluous, because he tacitly admits, and can duly 
 appreciate the necessity of the initiatory force. This 
 criticism may be deemed over-fastidious ; but when we 
 call to mind that it is only a few years ago when such a 
 man as Faraday did not hesitate to declare his perplexity 
 concerning gravitation, it affords sufficient evidence that 
 our knowledge on this subject is not very definite. Fara- 
 day has candidly expressed his opinion that the law of 
 gravitation is at variance with the principle of the conser- 
 vation of forces ; he argues that the increase and decrease 
 of this force, according to the position of a body, seem 
 to indicate a creation and annihilation of force ; and if our 
 memory fail not, he came to the conclusion that the phe- 
 nomenon could not be explained unless by the joint idea of 
 polarity, such as that of magnetism, an antagonism of op- 
 posite poles which might throw some light on the subject. 
 
 This difficulty is, we think, easily explained on the 
 
DUALISMS OF PHYSICAL POWERS. 51 
 
 view which we are advocating, that gravity and centrifugy 
 constitute a dualism of physical powers. For it follows 
 that since they are both ever present, acting on each other 
 in opposite directions, an additional force in either one or 
 other direction must increase the relative proportion of 
 the corresponding force. For instance, the sun draws a 
 planet, and the planet the sun, and the tendency of this 
 mutual action is to bring the bodies together, but at the 
 same time these bodies mutually repel each other, and the 
 result of this conjoint action and reaction is that the 
 planet occupies a position at a definite distance from the 
 sun, where these forces are in a state of equilibrium. 
 Now, thus circumstanced, the planet is in a condition to 
 respond to any external impulse, whether toward or from 
 the sun, as happens in the case of natural perturbations ; 
 but in whatever direction this takes place, the force over- 
 powered, by any intervention, is in nowise diminished in 
 energy ; for as soon as the extraneous force is withdrawn 
 the planet regains its original position, precisely as a gas 
 when condensed is restored by its inherent elasticity to its 
 former volume on removal of the condensing pressure. So 
 if a body be forcibly brought nearer to the centre of 
 gravity of another body, the force employed in effecting 
 this is equivalent to an increase of gravity since it acts in 
 the same direction ; and so if a body be projected from . 
 the earth, the relative proportion of its attraction and 
 repulsion is altered thereby, and when the dominating 
 force is dissipated its inherent gravity comes into play 
 and restores the body to the earth. 
 
 The increase and decrease of forces, continual occur- 
 rences in every department of nature, are not indications 
 
 2 
 
52 MATEKIAL ATOMS AND MASSES. 
 
 of the creation and annihilation of force, but are only 
 local disturbances of co-existing and opposite forces by 
 the variations of their relative proportions; whilst the 
 total amount of these forces in the entire system remains 
 unchanged according to the principle of the conservation 
 of forces. 
 
 Let us now endeavour to apply this assumption, that 
 gravity and centrifugy constitute a dualism of correlative 
 forces, to the explanation of some astronomical pheno- 
 mena, and more particularly of those of the solar system. 
 
 The solar system is supposed to have originally con- 
 sisted of one vast sphere of nebular matter, revolving on 
 its axis, and from which all the parts of the present 
 system have been derived by continuous condensation 
 around its centre, accompanied by successive and periodi- 
 cal disruptions at the circumference of the sphere. But 
 before noticing these developments of the solar system it 
 may be as well to inquire concerning its relations with 
 the universal system. 
 
 Is the solar system, as a subordinate, immediately and 
 directly connected with the common centre of the uni- 
 verse? Or is it associated with another sun after the 
 manner of binary stars, and this combination in its turn, 
 through ascending series of generalisations, connected 
 with the summum genus of the universal system ? Many 
 circumstances seem to indicate that the latter is the more 
 probable relationship. The retrograde motions of Ura- 
 nus' satellites and the great inclinations of their orbits to 
 the ecliptic, point to some disturbing influence on the 
 confines of our system, such as might be induced by the 
 action of a twin sun. The parabolic course also of some 
 
DUALISMS OF PHYSICAL POWERS. 53 
 
 comets, which implies that their return to our system is 
 not probable, might by a twin sun be so diverted and 
 curved around its focus as to enable them to complete 
 their orbits by an inverse and retrograde motion. 
 
 Our sun not only rotates on its axis, but has an onward 
 course in the heavens, carrying along with it all the parts 
 of its system, and moving at the rate of 150 millions of 
 miles during a terrestrial year. According to M. Arge- 
 lancler, this course tends, by some grand path, towards a 
 point in the constellation Hercules; this apparent path 
 may well seem to be undeviating, when the nearest fixed 
 star is about twenty billions of miles off a distance almost 
 inconceivable. It is probable that the sun's course is 
 curved like that of other celestial bodies, so that the 
 direction in which it points will vary accordingly. It is 
 not, however, probable that this course lies through the 
 immensity of space, immediately influenced by the central 
 attraction of the universe; analogy rather leads us to 
 expect, that as the solar system is comparatively small 
 and definite, that its orbit will partake of a similar cha- 
 racter : even if the diameter of its orbit were three billions 
 of miles, its circumference of about ten billions would find 
 ample space for its revolution and that of its twin sun 
 within the bounds of other stellar systems. 
 
 But where is this twin sun to be found ? Did we but 
 know its position and motion we might hope to be able to 
 settle our sun's path. It is possible that this sun may 
 only exist as a star so small as hitherto to have escaped 
 observation, as happened in the case of the planet Uranus. 
 It has also been conjectured that this body may be opaque, 
 and consequently only visible by reflected light, and if so, 
 
 E 3 
 
54 MATERIAL ATOMS AND MASSES. 
 
 it could but appear as the faintest of nebulae, for its distance 
 is probably thrice that of Neptune from the sun. This 
 conjecture is so far consistent, that whether a body be 
 autopliotic or not, it is still capable of acting and reacting 
 on other bodies, according to the laws of central forces ; 
 and though the bodies of the twin suns are far apart, their 
 systems, with their enveloping spheres of ether, may be 
 approximated or even overlapping each other, so that 
 their respective currents of undulations may freely mingle 
 and intersect each other, by which the communication of 
 the physical forces would be maintained. But in what- 
 ever way the solar system may be connected with other 
 systems, this one thing is certain, that it cannot stand 
 alone, but must be in relation with others, as being an 
 integrant part of the universal system. 
 
 The solar system, in its individuality, is supposed to 
 have been originally one rotating sphere. A sphere 
 which, throughout all its parts, was subject to the action 
 and reaction of the physical forces attraction and repulsion, 
 the former concentrating its energy at the centre, and the 
 latter at the circumference; the immediate parts of the 
 sphere communicating together by axial currents of gravity, 
 and by equatorial currents of centrifugy. In this manner 
 all the parts of the sphere are held together, bound, as it 
 were, to the axis of gravitating force, whilst at the equator 
 the parts of the sphere experience a constant tendency to 
 he thrown off by centrifugy. Such a system, though 
 nearly spherical, that is, in a state of equilibrium, would 
 not be homogeneous, but made up of concentric zones, the 
 inner ones gradually increasing in density as the outer 
 ones do in rarefaction ; there would, however, be an inter- 
 
DUALISMS OF PHYSICAL POWERS. 55 
 
 mediate zone in which these properties are equal, a nodal 
 region of statical rest, a condition favourable to a momen- 
 tous change in the system. 
 
 We are not able to determine whether the universal 
 sphere of ether was disturbed by the interposition of 
 chemical powers, or whether this cause of differentiation 
 was reserved for our solar system ; at all events, the latter 
 seems to have been constituted as an aggregate of chemical 
 substances in a vesicular or nebular state, interpenetrated 
 by, and immersed in, the ocean of ether. Now, by the 
 very act of the formation of the chemical elements by the 
 union of physical and chemical powers, an enormous con- 
 densation must have taken place, accumulating gravitating 
 matter at the centre, and extricating an enormous heat, 
 which would flow outwardly as* centrifugal force, thereby 
 accelerating the rotation of the sphere. Our idea of 
 rotation is so naturally formed on the spinning round of a 
 solid in which all the concentric parts, though increasing 
 in volume, according to their distance from the centre, 
 perform their revolution in the same time, that it is diffi- 
 cult to imagine the internal condition of a rotating nebular 
 sphere, but in all probability its concentric zones have 
 different times, according to their densities, imparting a 
 spiral arrangement, and such a condition is confirmed by 
 the observed forms of many nebulae now existing. 
 
 The experiments of Professor Plateau * on the figures 
 of rotating liquid masses ai*e very interesting, and in some 
 degree are applicable to fluids generally ; the condition of 
 aerial motions around rotating bodies also offers a good 
 
 * Taylor's Scientific Memoirs, vol. iv. p. 16. 
 E 4 
 
56 MATERIAL ATOMS AND MASSES. 
 
 subject for investigation. But whether the internal motion 
 of the nebular sphere be spiral or concentric, there is a 
 constant tendency of the equatorial fluid part to extend 
 itself uniformly in a given plane ; and thus it is that the 
 positions and motions of the now independent portions of 
 the system are all nearly related to the ecliptic. In the 
 case of the sphere, there is a limit to its extension ; when 
 the continually increasing centrifugal force, increasing 
 pari passu with the central condensation, has reduced the 
 sphere to an extreme state of ellipticity, the tension of 
 gravity will be overcome, and a fission of the sphere pro- 
 duced, which will be greatly facilitated and determined by 
 the nodal zone of equilibrium. This fission would have 
 been immediately followed by a collapse of the inner 
 sphere, and consequently by a renewal of the process of 
 condensation, as the first step in the repetition of a similar 
 series of operations. The detached zone would whirl 
 around in eddying waves, gradually enlarging its undula- 
 tions until it reached that position in space where the 
 mutual attractions and repulsions, between it and the 
 inner sphere, now become a sun to the outer planetary 
 zone, arrive at a state of equilibrium. The ring would 
 continue to rotate, until by its rupture, which the spiral 
 motion greatly aids, it would be rolled up and gathered 
 together into a distinct planet. The explosion of a bubble 
 of phosphuretted hydrogen, when the air is still, gives an 
 apt illustration of this nebular ring and its subsequent 
 rolling up into a cloud, which only wants the restraint of 
 a central attraction to complete the analogy. We need 
 not, however, follow out the formation of each planet by 
 the successive fissions of the central sphere, nor that of 
 
DUALISMS OF PHYSICAL POWERS. 57 
 
 the rings and satellites of the planets by the repetition 
 of a similar process, for this has been already fully de- 
 scribed by Laplace in the explication of his celebrated 
 theory. 
 
 The theory of Laplace accounts for the rotation of the 
 sun and of the planets in the same direction, and in nearly 
 the same plane, by ascribing them to the original rotation 
 of the primaeval system ; so far, this is preferable to the 
 notion of an initiatory impulse for each planet by divine 
 interposition, but it gives no insight into the cause of this 
 original rotation, nor into the nature of the condensation 
 which produced the intense ignition. " The cosmogony 
 of Laplace," says Comte *, ee seems to me to present the 
 most plausible theory of any yet proposed. It has the 
 eminent merit of requiring for the formation of our system 
 only the simple agents weight and heat, which meet us 
 everywhere, and which are the only two principles of action 
 which are absolutely general." And why are these prin- 
 ciples two in number? And why are they general? 
 Because matter itself, the sum and substance of the 
 system, is a dualism of attraction and repulsion, and all 
 the various physical forces are only modes or phases of 
 these powers ; one while attraction is manifested as solidity 
 and at another as weight, being called cohesion or gravity 
 according to its mode of action, and so in like manner 
 repulsion may appear as either centrifugy or heat. These 
 antagonistic forces, by their actions and reactions, produce 
 all physical phenomena, and since they co-exist throughout 
 nature, they must be absolutely general. 
 
 * Positive Philosophy, vol. i. p. 211 
 
58 MATERIAL ATOMS AND MASSES. 
 
 The principle of dualism teaches us that the solar sys- 
 tem, in its present condition, is actuated by the central 
 forces in a similar manner as when it was originally one 
 uniform sphere. It now, as then, rotates by the action of 
 the same tangential currents ; then, indeed, they traversed 
 a mass somewhat homogeneous, but now they traverse 
 different media, and are consequently modified thereby. 
 Thus from the centre to the surface of the sun the medium 
 is very different from that of the ether of space, and there- 
 fore the undulating currents, though capable of being pro- 
 pagated through both media, cannot be so in precisely the 
 same manner : just as molecular undulations as sounds are 
 transmitted through both solids and the atmosphere, 
 though their velocity and other conditions greatly vary 
 according to the medium. What we are desirous of 
 maintaining is that the planets are still connected with 
 the sun by tangential currents of forces, just as when 
 they formed continuous parts, or concentric zones, of the 
 same sphere ; that they are thereby maintained in definite 
 positions, which in relation to the sun are those of equi- 
 librium, and that their revolutions are concentric rotations 
 of their parts of the system, all of which are regulated by 
 and centre in the sun ; the solar system being still vir- 
 tually but one sphere of revolving ether, the sun and its 
 planets being parts, predominant indeed, but still parts of 
 the same sphere. 
 
 From this it follows that rotation on an axis is the one 
 and universal motion produced by the action and reaction 
 of central physical forces, and however varied the 
 different kinds of motion may be, they are but diverse 
 asp ects or modifications of rotation. 
 
DUALISMS OF PHYSICAL TOWERS. 59 
 
 In a system thus constituted we see why comets in 
 their eccentric courses, crossing many planetary zones, 
 may suffer perturbation in their passage through ether ; 
 whilst the planets are less liable thereto, not only on 
 account of the greater density of their bodies, but also 
 because they are moving in the same direction as the ether 
 itself, which is also rotating as part of the solar system. 
 
 The view which we have been advocating concerning 
 the relations of gravity and centrifugy in astronomical 
 phenomena is suggestive of many remarks on other parts of 
 this subject ; such remarks may, on examination, prove 
 for the most part worthless, still the very process of re- 
 futing them may elicit truths which would have otherwise 
 escaped attention. 
 
 How came it to pass that the planets, as we recede 
 from the sun, are separated from each other by distances 
 of a progressively increasing ratio ? According to Bode's 
 law, if the distance between Mercury and Venus be taken 
 at three, the successive doubling of this number with the 
 common constant of 4 for each planet gives the ratio of 
 the planetary distances from the sun. This hypothesis 
 has been found to answer except in the case of Neptune, 
 which makes a breach of the law ; this law, however, is 
 wholly empirical, it offers no physical explanation of the 
 regularity of an arrangement which cannot be devoid of 
 some rational foundation. 
 
 Such an arrangement we conceive was produced in 
 accordance with the construction of the original sphere 
 from which the planets were evolved. As already stated, 
 the tangential currents of central forces which actuated the 
 sphere, by their interferences produced nodal lines, on which 
 
60 MATERIAL ATOMS AND MASSES. 
 
 ruptures would take place as points of least resistance ; 
 these lines, from the centre to the circumference of the 
 sphere, would comprise spaces progressively increasing just 
 as the law of radiation ; and consequently the planets when 
 evolved would partake of the same symmetrical arrange- 
 ment. And if so the position of the planets might possibly 
 have been determined a priori by geometrical processes. 
 
 On the same principle we account for the enormous 
 volume and the comparatively small weight or gravitating 
 matter in the outer planets, whilst the inner planets are 
 small and ponderous, gravity being in the ascendant in 
 the latter, centrifugy in the former. For the condition of 
 the intermediate asteroids we also find some explanation 
 in supposing it to be the intermediate region of the solar 
 system, where the central forces are in a state of equili- 
 brium. Not the original node of the total central forces, 
 but the resulting node from the then existing altered state 
 of the system, and during such a balanced state it might 
 be expected that small accessions of centrifugal force 
 would operate promptly and repeatedly in the successive 
 discharge of small zones, containing but little ponderable 
 matter. Be this as it may, the fact is that the mass of the 
 planetoids is very small, even thirty of them not exceeding 
 a quarter part of the earth's weight. Olbers has suggested 
 the idea, that these numerous planetoids have been pro- 
 duced by the explosion of a planet which ought, according 
 to Bode's law, to have existed between Mars and Jupiter. 
 But granting the possibility of such an occurrence, the frag- 
 ments ought to have returned, and circulated around their 
 original centre of gravity. 
 
 In the consideration, however, of the distances, volumes, 
 
DUALISMS OF PHYSICAL POWERS. 61 
 
 and weights of the planets, there are many irregularities 
 which are not fully resolved by the above explanation. 
 For instance, Neptune is not as distant from the sun as 
 the increasing ratio of the adjacent planets would lead us 
 to expect; and, moreover, Neptune has one- third more 
 matter and double the specific gravity as Uranus, whilst 
 their volumes are very nearly equal. As the existence of 
 a twin sun is uncertain, we cannot speculate on the prob- 
 able influence of such a perturbation on the outer region 
 of our system. But chemical forces may be verce causce, 
 which must not be overlooked. We know that many sub- 
 stances in a state of vapour are highly rarefied, and yet 
 condense into dense liquids and solids; whilst, on the other 
 hand, some vapours are very ponderous, and yet when 
 solidified form substances of low specific gravity; and be- 
 tween these extremes there are great variations. It does 
 not follow that the chemical elements known to us exist 
 in any other planet, and the awanting numbers in the 
 scale of chemical equivalents are sufficiently numerous to 
 afford a great variety of unknown chemical elements. And 
 if so, the corresponding variety of physical properties, 
 which such elements would possess, might afford data for 
 the explanation of some of the planetary peculiarities. 
 
 The great latitude which has been permitted in astro- 
 nomical speculations, is our only apology for venturing to 
 offer a reason, but probably not the reason, why our earth 
 alone of all the inner planets has got a moon, and why, 
 coincidently with this circumstance, the distance between 
 the earth and Mars is almost double that between the 
 earth and Venus. This would seem to indicate that there 
 is a planet awanting between the earth and Mars; and may 
 
62 MATERIAL ATOMS AND MASSES. 
 
 not the moon be that planet, drawn out of its orbit by- 
 some extraordinary occurrence ? We search in vain for a 
 physical, but may there not be a chemical cause? The 
 waters, which now cover so large a portion of the earth's 
 surface, could not have existed as a chemical compound, 
 but only as oxygen and hydrogen during the intense heat 
 of the earth long after its formation, nor could they have 
 combined until the earth had experienced a great reduction 
 of temperature ; but when their union did take place, the 
 explosion must have been stupendous. Could not the re- 
 coil of such an explosion have been sufficient to have 
 drawn the adjacent small planet, Luna, within the influence 
 of the earth's attraction ? 
 
 The sun which originally, as the entire solar sphere 
 possessed a radius of probably not less than 10,000 millions 
 of miles, has, by successive fissions and separations of 
 planetary zones, been reduced to a diameter of 882,000 
 miles ; and its period of rotation has by the same events 
 been brought down from about 200 years to less than 
 twenty-six days. Recent observations render it probable 
 that at least one planet exists between Mercury and the 
 sun ; but it is an interesting question whether the for- 
 mative process of the sun has yet terminated, whether the 
 production of new planets may be still looked for. The 
 appearance of the sun indicates that the first stage of such 
 a process has been commenced ; it is, however, not im- 
 probable that its present annular zone, and even succeed- 
 ing ones, may be permanent like the rings of Saturn. 
 The present ring is of a nebular or cometic consistency, 
 and acts the part of a photosphere, by becoming brilliantly 
 illuminated by the impinging rays proceeding from the 
 
DUALISMS OF PHYSICAL POWERS. 63 
 
 mass of the sun. Between this photosphere and the at- 
 mosphere of highly elastic vapours immediately resting 
 on the sun, there must be a zone of ether ; the sun and 
 its elastic envelope, including the ether, could not be 
 visible, but the rays darting from this intensely heated 
 mass, and impinging on the vesicular substance of the 
 photosphere, would produce a most dazzling effulgence, 
 just as dust or filings projected into a highly heated, but 
 invisible gas, immediately become luminous. The sun's 
 heat and light have been attributed to combustion, to 
 showers of aerolites falling on the sun, and to many other 
 causes ; but on the principle of " least action," the pheno- 
 menon is better explained by that process of condensation 
 which is going on at the centre of the system. The 
 vaporous state of the sun's atmosphere has been established 
 by the experiments of Arago on the polarisation of the 
 sun's light, and such an atmosphere would be subject to 
 similar currents from the equator to the pole, as take 
 place on our planet, accompanied by whirlwinds stupen- 
 dous exaggerations of our tropical tornadoes. Such vor- 
 tices, viewed by us, would have the appearance of spots 
 like those which occur on the sun, they would suck in 
 and be filled with ether, just as the interior of a whirlpool 
 is filled with common air ; and, consequently, the radia- 
 tions through the ether would be invisible, but striking 
 on the compressed sides of the vortices, the reflected rays 
 would render the sides luminous. These spots are con- 
 fined to a limited region on each side of the sun's equator, 
 and their increase and decrease, according to Schwabe, are 
 subject to a periodical cycle. 
 
 The curious and interesting phenomenon of the zodiacal 
 
64 MATERIAL ATOMS AND MASSES. 
 
 light was long regarded as the outer portion of the sun's 
 atmosphere, but, according to Laplace *, this is a dynamical 
 impossibility, for it could not extend, he says, more than 
 one-third of the distance between the sun and Mercury. 
 This limitation somewhat approximates to the node of 
 indifference where attraction and repulsion are in equili- 
 brium a limitation which S. M. Drachf places at sixteen 
 millions of miles from the centre of the sun. A very 
 prevalent opinion concerning this light is, that it is pro- 
 duced by the circulation of a stream of meteors around 
 the sun, which are individually too small to be discerned 
 otherwise than as diffused nebular light, but which period- 
 ically coalesce into larger bodies and become manifested 
 as showers of falling stars. According to our view of the 
 solar system, the zodiacal light may receive another expla- 
 nation. The vast expanse of ether within the bounds of 
 this system is an important constituent part thereof, and 
 since it is an elastic fluid, it must, in accordance with the 
 laws of such, experience condensation around every centre 
 of gravity ; and consequently the most considerable com- 
 pression in the vicinity of the sun, the general centre of 
 the system, in other words, the amount of condensation 
 would be according to the sum of attraction mutually 
 exerted between the sun and its ethereal atmosphere. 
 The substance of such a spheroid of compressed ether 
 would probably be much inferior to that of the rarest 
 comets, but still sufficiently dense to be illuminated by 
 the sun's rays. The lenticular form of the zodiacal light 
 is such as might be expected to result from the great 
 
 * Encyclopaedia of Physical Science. Art. Zodiacal Light, 
 f Times Newspaper, Feb. 2, 1859. 
 
DUALISMS OF PHYSICAL POWERS. 65 
 
 velocity of the sun's rotation ; and its position, a little 
 removed from that of the ecliptic, is in accordance with 
 this view. It may also be remarked that the existence 
 of such a region of condensed ether around the sun would 
 account for some of the changes which comets undergo 
 when in the vicinity of this luminary. This explanation 
 is not inconsistent with the view recently advanced by 
 Professor Olmsted of Yule College. " He agrees with 
 Laplace in thinking that this light is a nebular body 
 revolving in the plane of the solar equator ; and, from long 
 and careful observation, he is of opinion that it has a 
 period of something less than a year ; and in the position 
 assigned by him to its orbit, showers of shooting stars 
 may happen in April and November." * 
 
 Before concluding these brief and cursory remarks on 
 astronomical phenomena, we must not lightly pass over 
 that extraordinary class of cosmical bodies which, as 
 comets, form so interesting, yet erratic, part of the solar 
 system ; they have already furnished the means of becom- 
 ing better acquainted with its constitution, and will pro- 
 bably, when better understood, be instrumental in solving 
 many momentous problems. 
 
 Comets move in ellipses of various degrees of eccen- 
 tricity, and also describe other figures of the conic sec- 
 tions ; and this enables us to divide them into three classes, 
 the elliptical, the parabolic, and the hyperbolic comets. 
 Elliptical comets might also be termed solar, as their 
 orbits are confined to our system ; that is, these bodies not 
 only at their perihelion describe a regular curve, but also 
 
 * Mrs. Somerville's Connexion of the Physical Sciences, p. 449. 
 
 F 
 
66 MATERIAL ATOMS AND MASSES. 
 
 at their aphelion, which is within the limits of the sun's 
 attraction. Whilst, however, the planets form ellipses but 
 little removed from circles which are arranged concentri- 
 cally around the sun, the solar comets revolving in ellipses 
 of extreme eccentricity must necessarily intersect the 
 planetary orbits, and consequently be seriously affected 
 by their occasional proximity, though this is in some 
 measure diminished by the plane of the cometary orbits 
 being greatly inclined to the ecliptic. As regards the 
 substance of comets they all possess enormous volumes in 
 comparison to their weights; a constitution which also 
 characterises the outer planets, but which in the comets 
 is greatly exaggerated ; indeed their substance is so rare, 
 that stars even of small magnitude have not only been 
 seen through their tails, but even through the densest part 
 their nucleus or head. They probably consist of a 
 gaseous elastic fluid, rendered somewhat opaque for the 
 better reflection of light, by the diffusion of the vesicles 
 of volatile liquids. Such a material body, though capable 
 of retaining its individuality, would be so sensitive to 
 extraneous influences as to be perfectly Protean in form. 
 And such is the case with comets: one while they 
 are gathered together into regular spheres, at others 
 greatly elongated ; sometimes the lighter part trails behind 
 like the tail of a rocket, and this will continue as the 
 comet approaches the sun ; but after its perihelion the tail 
 will take precedence of the body. The reason of the 
 latter curious condition is, that the denser part of the 
 comet must needs be opposite to the sun, according to the 
 law of gravity ; and the lighter part must be in the con- 
 trary direction, elastic fluids becoming rarer and rarer as 
 
DUALISMS OP PHYSICAL POWERS. 67 
 
 they recede from the centre of attraction : so that in reality 
 the position of all the parts of a comet, in relation to its 
 centre of gravity, remains unaltered. It has been ascer- 
 tained that the nucleus of comets becomes much con- 
 densed as it approaches the sun ; <^hich from their elastic 
 constitution might have been anticipated : and such an 
 occurrence must be accompanied by an evolution of heat, 
 which accounts for the extraordinary splendour of some 
 comets in such a position ; an antophotence similar to that 
 of the sun, and having the self-same origin, that of 
 material condensation. 
 
 Strongly contrasted as planets and comets are, both in 
 their constitution and in their movements, there is every 
 reason to believe that, as parts of the same system, they 
 have been produced by the operation of the same causes, 
 under different conditions: central condensation by the 
 influence of gravity evolves centrifugal force, which tend- 
 ing outward, throws off a portion of the revolving sphere ; 
 and since all these portions are not similar, they manifest 
 that the action has taken place under different circum- 
 stances. The regular coherence of the sphere, and the 
 gradually increasing pressure of centrifugy, would quietly 
 separate the planetary zones ; but the presence of rarer 
 and less coherent matter, at the circumference of the 
 sphere, would modify the result; such matter might at 
 any time, more especially during periodical paroxysms, be 
 hurled off by centrifugal force, and be propelled with pro- 
 digious violence resembling the flight of a rocket. Such 
 discharges might take place during the evolution of each 
 of the planets, and their orbits would vary accordingly, 
 corresponding with the periods of their birth. This, how- 
 
 F 2 
 
68 MATERIAL ATOMS AND MASSES. 
 
 ever, is only conjecture, but it is consistent with facts; 
 rotation causes liquid spheres to become more and more 
 oblate, till they become a mere plane, and then throw off 
 a ring, that is if the rotation be equable and the material 
 sufficiently coherent; but if violent the parts fly off at 
 a tangent. We cannot pause to show how well this ex- 
 plains the positions of the inner or elliptical comets : but 
 there is one circumstance relating to Halley's comet, which 
 may be noticed. It. is the only one of all the known 
 periodical comets, which moves in a contrary direction to 
 that of the planets, that is, against the order of the signs ; 
 and it is worthy of remark, that its orbit extends beyond 
 that of Neptune, where a counter action may be in opera- 
 tion, such as a twin sun might produce, and which would 
 also account for the retrograde motion of Uranus' satellites* 
 The existence of a twin sun would account for the orbits 
 of the parabolic comets : such comets, whether projected 
 originally from the system of our sun, or from that of the 
 other sun, would follow a course almost straight, in the 
 region intermediate between the two systems, where the 
 forces of both are nodal; but on coming within the more 
 direct influence of either sun, their course would form re- 
 entering curves, and thus by inverse operations, may be 
 alternately restored to either system, revolving around its 
 respective sun. And so likewise hyperbolic comets 
 may not be wanderers through boundless space, travers- 
 ing all the systems of the universe, but the bonds of union 
 between our twin system and some other analogous 
 system, which though far removed from each other,, may 
 be periodically encompassed by these visitors ; that these 
 comets do not call once for all, and then desert us for 
 
DUALISMS OF PHYSICAL POWERS. 69 
 
 ever, though their visits are, like those of angels, few and 
 far between. 
 
 From this hasty sketch of the application of the principle 
 of dualism to astronomy, it is hoped that sufficient has 
 been said to show why we consider that this science is not 
 an artillery problem, as is generally supposed. "The 
 identity of weight and the moon's tendency toward the 
 earth," says Comte*, "places the whole of celestial 
 mechanics in a new light. It shows us the motion of the 
 stars as exactly like that of projectiles, which we have 
 under our immediate observation. If we could start our 
 projectiles with a sufficient and continuous force beyond 
 the resisting atmosphere, we should find them the models 
 of the planetary system, or in other words, astronomy has 
 become an artillery problem, simplified by the absence of 
 the resisting medium, but complicated by the variety and 
 plurality of weights." 
 
 The inadequacy of an initiatory impulse, as a primum 
 mobile, and as a counterpoise to the continuous force of 
 gravitation, has been discussed and shown to be superfluous; 
 since, in nature, there is a co-existent and opposite force, 
 which provides all the antagonism which gravity requires 
 in order to function as astronomical phenomena. If the 
 earth, as well as the moon, did not exert a mutually repul- 
 sive, as well as a mutually attractive power, toward each 
 other, they would inevitably come together; to prevent 
 this the tangential force must be continously applied ; one 
 artillery discharge would not be sufficient, an incessant 
 succession of discharges would be required to balance the 
 
 * Positive Philosophy, vol. i. p. 181. 
 F 3 
 
70 MATERIAL ATOMS AND MASSE 84, 
 
 continuous currents of gravitation. This is well illustrated 
 by the familiar toy of the pea and tobacco pipe, and also 
 by a ball playing on the top of a water jet ; in both cases 
 the rotating projectiles can only be maintained in an ele- 
 vated and definite position, by continuous impulses. 
 Comte, in his analogy, postulates the absence of a resisting 
 medium which cannot occur ; for the ether of space meets 
 us in every part of the solar system, an important material 
 constituent without which physical forces could not operate. 
 Now such a medium, if astronomy were a mere artillery 
 problem, would as surely cause a planet to fall, as an 
 ordinary projectile; whereas we know that the orbits of 
 the planets, though continually perturbed, are perpetually 
 conserved as instantaneous ellipses. 
 
 This subject is very interesting, but we must conclude 
 with pointing out how the natural powers thus far obtained 
 are related in their respective dualisms. 
 
 Attraction + repulsion = physical substance or matter. 
 Gravity + centrifugy = celestial bodies or stars. 
 
 The action and re-action of the correlative forces of matter 
 produce physical phenomena, and the correlation, matter, 
 is the subject or noun-substantive of physics. So the stars, 
 using the term in its largest sense, are particular forms of 
 matter, and as such the subject of the particular physical 
 science, astronomy. Descriptive astronomy is the natural 
 history of the stars depending on definitions and classifica- 
 tion; physical astronomy regards the internal constitution 
 of the stars, as compounds of gravity and centrifugy; and 
 a knowledge of the action and re-action of these forces 
 constitutes celestial mechanics. 
 
CHAP. III. 
 
 THE MOLECULAR FORCES, COHESION AND HEAT, MODES 
 OR PHASES OF PHYSICAL POWERS. 
 
 All modes of Physical Forces function in some form of Motion. 
 Molecular motions individually inappreciable : only manifested in 
 the aggregate. Molecular Attraction called Cohesion. Molecular 
 Repulsion, expansive Force or Heat. The term Micronomy pro- 
 posed for Molecular Physics. The Solid, Liquid, and Gaseous states 
 of Matter. The nature of Latent Heat. The Spheroidal Form 
 of Boutigny, not a fourth state of Matter. Cohesion a quantitative ; 
 Heat a qualitative Force : the former fixed and definite ; the latter 
 diffuse and variable. Condensations of Gases in porous Bodies. 
 Action of a plate of Platinum. The Quantity of Heat only deter- 
 mined relatively to a given Standard. The Zero of Heat unknow- 
 able. The Conduction of Heat. Expansion. Motion of Mole- 
 cules and Motion of Mass modes of the same Phenomenon. Joule's 
 Equivalent of a Unit of Heat. Convection of Heat in Fluids. The 
 ratio of Expansion in Gases. Expansion not an invariable indica- 
 tion of an increment of Heat. Specific Heats. Condensation 
 evolves Heat: Heat absorbed on Rarefaction. Diffusion of Liquids 
 and Gases. Osmotic Phenomena. The Sum of Latent and Sen- 
 sible Heats and Vapours, the same for all tensions. High pressure 
 Vapours Paradoxical effect of. Caigniard De la Tour's Ex- 
 periments thereon. Molecular Attraction. Crystallisation. 
 Isomorphism, Dimorphism. Allotropy. Conclusion. 
 
 HAVING considered the forces of gravity and centrifugy, 
 as modes of the universal dualism of the physical powers, 
 attraction and repulsion; and having shown that these 
 
 F 4 
 
72 COHESION AND HEAT, MOLECULAR FORCES. 
 
 reason- directed forces are the immediate causes of celestial 
 phenomena ; we now turn to the consideration of physical 
 powers, under a different aspect, as molecular forces, the 
 causes of the different states of matter. 
 
 The changes of material bodies, which take place as 
 molecular motions, are so minute that they cannot be 
 individually seen and measured : these constitute the 
 subject matter of molecular physics, a science much more 
 complicated than astronomy, and, consequently, not so far 
 advanced in its development ; but one which, notwith- 
 standing its intricate character, is making good progress in 
 consequence of the superior advantage which it enjoys in 
 the privilege of experimenting, by which it is enabled to 
 reproduce its phenomena at pleasure, for the verification 
 of observations. 
 
 We proceed in the first place to inquire into the nature 
 of the forces which actuate the molecules of material 
 bodies. These forces produce motions, and it is thereby 
 determined that they are phases of physical powers, for 
 it is the characteristic attribute of such powers to cause 
 motion, that is, change of position in space. The forces 
 which we now have to deal with do not exert their influ- 
 ence over vast extents, from common centres, though they 
 are fundamentally modifications of the same universal 
 attraction and repulsion ; but, having a different field of 
 action, they assume a different aspect. The molecules of 
 matter attract each other, and become aggregated together 
 into various forms, and the force by which this is effected, 
 is called cohesion : the molecules, however, thus aggregated, 
 never come into actual contact, but are kept apart, at 
 various distances from each other, by a repulsive energy^ 
 
SPECIFIC MODES OF PHYSICAL POWERS. 73 
 
 inherent in the molecules, and co-existent with cohesion; 
 a mode of repulsion which is distinguished from centrifugy 
 as expansive force or heat. Cohesion and heat are, there- 
 fore, the correlative phases of physical forces, as viewed 
 in relation to molecules, just as gravity and centrifugy are 
 phases of the same universal powers, in relation to cosmi- 
 cal masses or stars. The terms cohesion and heat are so 
 firmly established that we shall continue to use them, 
 though the former gives a very inadequate idea of the at- 
 traction concerned in liquids and gases; we should have 
 preferred such terms as those of synogy or synogetic force, 
 and thermacy or thermotic force. 
 
 Whilst engaged in preliminary remarks, we may also 
 notice what appears to us an ill-advised and unsyste- 
 matic attempt to construct a science of heat, as Thermotics. 
 The analogy which seems to have suggested the attempt 
 13 that of dynamics in rational mechanics : but if such a 
 proceeding were sanctioned, we ought, according to this 
 rule, to have also sciences of centrifugy and of gravity, 
 which would be superfluous, since astronomy is compre- 
 hensive enough to embrace all these considerations ; and 
 so molecular physics includes within its scope all that need 
 be known concerning heat and cohesion, the correlative 
 powers of its dualism. It would, however, be convenient 
 if we had an individual name for molecular physics : this is 
 good as far as it goes, just as we speak of celestial physics 
 to mark another branch of general physics ; but which is 
 better distinguished by the special name of astronomy. 
 So molecular physics ought to have a particular name, and 
 we think that of micronomy might answer the purpose. 
 Then micronomy would be the science or systematic know- 
 
74 COHESION AND HEAT, MOLECULAR FORCES. 
 
 ledge of small things or molecules, as astronomy is that of 
 celestial masses or stars. 
 
 When treating of a rotating body, or system of bodies, 
 we saw that the central forces were unequally distributed ; 
 that whilst gravity prevailed at the centre and centrifugy 
 at the circumference, these forces at the intermediate part 
 of the system were in a state of equilibrium. Molecular 
 forces also are capable of a similar unequal distribution ; 
 but the circumstances being different, the phenomena 
 by which they are manifested assume different characters. 
 We deal not now with an entire system made up of many 
 parts and concentrated around a common centre ; but we 
 regard distinct individual parts of the system, and find that 
 in such limited portions of matter the molecules may be 
 one while under the influence of an excess of cohesion, and 
 at another of heat ; or they may be in a statical state, these 
 forces being equal. So that we can consider molecular 
 bodies under three distinct forms, commonly called the 
 states of matter ; the solid, the liquid, and the gaseous 
 or vaporous ; and it is now admitted that it is physically 
 possible for all bodies to be capable of existing in either or 
 all of these states. 
 
 In considering the changes of bodies from one state to 
 another ; we naturally view them from our every-day, 
 or common sense stand-point: surrounded as we are by 
 the effects of gravity, we are more impressed by the state 
 of. solidity than of the others ; and so we ordinarily speak 
 of the melting of solids, and the boiling of liquids ; and thus 
 Miller in his Chemistry says, that "all gases may be 
 regarded as the vapours of liquids of an extreme degree of 
 volatility.' The course of nature, however, seems to have 
 
SPECIFIC MODES OF PHYSICAL POWERS. 75 
 
 been the reverse of this : originally all material things ex- 
 isted as highly elastic fluids, and the solids and liquids which 
 we now see around us are condensations from the normal 
 gaseous condition by the interposition of extraneous 
 forces. When we treat of chemistry, this will be more 
 fully explained 5 but in the meantime it must be borne in 
 mind that each element has a material or physical body 
 of a specific atomic weight and of a definite volume ; and 
 hence it is that the different kinds of molecular substances 
 vary so greatly in their physical properties according to 
 the relative masses of the chemical atoms, as is well 
 illustrated in the case of the specific heats of different 
 bodies. For, of course, if the molecules to be moved 
 differ in weight and volume, they will require the appli- 
 cation of different amounts of force to change their con- 
 dition. Recent researches have shown that the weights 
 of equal volumes of most gases (and of vapours when 
 sufficiently removed from the point of liquefaction), are in 
 the ratio of the chemical equivalents ; but in the case of 
 liquids and of solids no such relation obtains. In solids 
 the molecules are frequently arranged in symmetrical 
 forms, varying greatly in volume, and a careful attention to 
 their atomic volumes as well as their atomic weights, would 
 give a mean result, which might explain the physical pro- 
 perties of many substances. 
 
 Let us briefly illustrate the relations of the correlative 
 molecular forces, in the three states of matter, as ice, 
 water, and steam. Ice is a crystalline solid in which 
 cohesion predominates over heat; the latter force is also 
 present and acts the part of the passive or resisting force 
 in the composition of forces, the material body or dualism 
 
76 COHESION AND HEAT, MOLECULAR FORCES. 
 
 of physical powers. By the predominance of cohesion in 
 ice the molecules are brought together and constrained at 
 so many different points that there is little freedom of 
 motion, and that only corresponding to the crystalline 
 axes. At the earth's surface ice melts when the tempe- 
 rature rises above 32 Fahr. and it becomes water ; the 
 excess of its cohesive force being balanced by the acquired 
 heat, the molecules are in a statical state and free to obey 
 an impulse in either direction, whether that of heat or 
 cohesion. In the liquid state it is evident that, although 
 neither one nor other of the molecular forces predominates, 
 both are present ; for small portions or drops attract each 
 other and run together, and maintain a spheroidal form, 
 but cannot so far cohere as to become solid on account of 
 the repulsive energy of the combined heat. Under or- 
 dinary circumstances if water be heated to 212 it flies off 
 in the form of steam or gaseous vapour ; in steam heat is 
 in the ascendant, and in consequence thereof its molecules 
 repel each other with great energy, so that cohesion exerts 
 its force inwardly toward condensation, in which respect 
 its action is analogous to that of gravity ; and heat, like 
 centrifugy, has an outward tendency, putting the mole- 
 cules in motion by expansion, which, utilised by mechanical 
 contrivances, becomes a driving power in the industrial 
 arts. 
 
 This statement, though correct as far it goes (only 
 pointing out that material bodies melt and boil under 
 ordinary circumstances at definite and unvarying tempe- 
 ratures), yet it leaves out of notice a most important 
 consideration, viz. that such changes do not take place 
 suddenly when the given temperatures are attained, but 
 
SPECIFIC MODES OF PHYSICAL POWERS. 77 
 
 gradually, during which a considerable amount of heat 
 disappears or becomes passive or latent, as it is termed, 
 and is the efficient cause of the change of condition. The 
 operation is very simple. In liquefaction, for instance, the 
 molecules of the solid are held in certain positions by an 
 excess of cohesion, and when they arrive at such a tempe- 
 rature that they cannot be farther moved without changing 
 their relative positions, on which solidity depends, they 
 require sufficient heat to equalise cohesion before they 
 can be maintained in new positions; and so when the 
 liquid returns to a solid the process is reversed.* In 
 vaporisation a similar action takes place, only in com- 
 parison to that of liquefaction a much larger proportion 
 of heat is required ; but this is accompanied by a corre- 
 sponding increase in the result, for the molecules are 
 removed much farther from each other, and therefore, 
 as might be expected, require a greater force to preserve 
 them in such a position. These changes of state, like the 
 change of a body from rest to motion, depend on the 
 alteration of the previous relation of its correlative phy- 
 sical forces ; if a body at rest is to be moved, the force 
 which keeps it stationary must be balanced or neutralised 
 by an opposite kind of force, and during the accomplish- 
 ment of this object the latter force will appear to be 
 entirely lost or rendered latent, though in fact it is per- 
 fectly efficient, operating in overcoming the force which 
 tends to produce a state of rest. And thus a liquid is like a 
 machine at the point of moving, its forces are statically 
 balanced, and it is ready to obey an excess of either of its 
 forces, attraction or repulsion ; becoming either solid or 
 gaseous, according to the character of the predominant 
 
78 COHESION AND HEAT, MOLECULAR FORCES. 
 
 force, just as the machine, under like circumstances, either 
 moves or falls back into a state of rest. 
 
 We must not omit to notice the spheroidal form which 
 liquids assume when poured on very hot metallic surfaces, 
 which has been carefully investigated by M. Boutigny, 
 who regards it as a new or fourth state of matter : but 
 we cannot accept his conclusion ; for although the ap- 
 pearance is very curious, it is not singular ; it is still that 
 of a liquid in an unusual position. It seems to belong 
 to the same class of facts as liquid globules on repulsive 
 surfaces, as dew on the leaves of plants, drops of oil on 
 wet paper, of mercury on the table, and the like ; in all 
 of which gravity being equipoised, the attraction of co- 
 hesion between the molecules of the liquid comes into 
 play and arranges them around a common centre, which 
 produces the globular form. The concomitant phenomena 
 of spheroidal heat, such as the reduction of temperature 
 in the interior of the globular liquid by its superficial 
 evaporation, and others, are secondary results arising from 
 the ordinary relations of liquids to heat. The main cir- 
 cumstance, the elevation of the spheroidal liquid above 
 and completely out of contact with the heated metal, seems 
 to depend on the evolution of high pressure vapour, in 
 the first instance, which may be continued by the same, 
 or by a current of highly heated air, as when the experi- 
 ment is performed on wire gauze over the flame of a lamp. 
 In short, it is precisely of the same character as some 
 paradoxical effects of solid carbonic acid ; this substance, 
 though possessing the astonishingly low temperature of 
 106, may be immersed in water without causing it to 
 freeze, and may even be handled with impunity; whilst 
 
SPECIFIC MODES OF PHYSICAL POWERS. 79 
 
 iron only at 40 will destroy the flesh as effectually as 
 the actual cautery : but these facts are easily explained, 
 for the solid acid, in fact, never touches either the water 
 or the hand, but is separated therefrom by an atmosphere 
 of its own vapour in a high state of elasticity. 
 
 The different states of matter are so distinct and so 
 peculiarly characterised that their consideration, as sepa- 
 rate branches of knowledge, is readily suggested ; and 
 the more so as by such a method we are enabled to treat 
 of the motions of all the various natural bodies under the 
 three heads of solids, liquids, and gases. These branches 
 of molecular physics are very important, and their culti- 
 vation has been promoted by the application of the most 
 profound processes of the calculus ; but they still afford a 
 wide field for investigation. The gaseous state of bodies 
 is the one which of late years has been most studied, in 
 consequence of the great importance of steam, as a moving 
 power ; it is. also much more simple in its relations, the 
 predominance of repulsion obliterating those innumerable 
 differences which the atomic weights of molecules occasion 
 in solids by acting in the same direction as cohesion ; and 
 hence it is that many generalisations have been arrived 
 at, as those concerning the condensation, expansion, and 
 diffusion of gases. The weights and volumes of bodies 
 are ever varying according to the relative proportions of 
 their constituents, the molecular forces ; these, as the 
 results of the actions and reactions of their forces, are 
 important considerations, but let us observe the modus 
 operandi of these forces. 
 
 In astronomy we have no power to alter the course of 
 nature, the science is purely one of observation; but in 
 
80 COHESION AND HEAT, MOLECULAR FOECES. 
 
 micronomy we can subject the objects of study to experi- 
 ments, we can alter the relations of their correlative forces 
 by the addition or subtraction of either, and note the 
 results. In such experiments it has been found that 
 molecular forces, cohesion and heat, comport themselves 
 very differently. If we take a body having a definite 
 weight and volume, we can augment the latter consider- 
 ably by placing it near another body which is much 
 hotter, that is, which has an excess of thermotic force; and 
 the increase of its volume will be in proportion to the 
 degree of heat employed. On removing the expanded 
 body from the source of heat, it will gradually return to 
 its original volume ; but in all its changes its weight will 
 remain unaltered. Now if we desire to reverse the ex- 
 periment by placing a body of great density in contact 
 with a lighter body, we find no tendency to an equilibrium 
 of density, for each body retains its original weight. It 
 is true that a similar state of things occurs in astronomy ; 
 gravitation is a fixed and invariable quantity in each 
 member of the solar system, whilst centrifugal force is 
 in a continuous current of diffusion from the centre to 
 the extreme limits of the system ; and this fixed stability 
 of the one force seems to determine the position of the 
 axis, whilst the outward pressure of the other force causes 
 the equatorial rotation. Thus in the dualism of physical 
 powers, it would appear that attraction, in all its phases, 
 is the quantitative force, whilst repulsion and its congeners 
 are qualitative. But even in the case of gravitation, we see 
 a force concentrated at the centre of a system and acting 
 with its united energy on other bodies; so that turn it 
 as you may, there seems to be a deficiency of explanation 
 
SPECIFIC MODES OF PHYSICAL POWERS. 81 
 
 in the case of cohesion, the attractive force in molecular 
 physics. There is evidently something awanting akin to 
 the central action of gravity : we can detect some indi- 
 cations of it, but it looms very hazily. 
 
 The weight of bodies can only be altered by adding or 
 abstracting ponderable molecules ; but may they not exert 
 attractive and condensing influences on each other, so as 
 to alter the relative weights of their parts whilst the 
 entire weight of the whole is conserved? In searching 
 for a corroboration of this conjecture, the attention must 
 be turned to those bodies which are far removed from 
 each other in density, such as solids and gases. Now we 
 know that when gases are subjected to the action of that 
 very dense substance platinum, they have been found to 
 experience unlooked-for changes. Had this experiment 
 been only tried with one gas at a time, or with gases 
 having no affinity for each other, the resulting phenome- 
 non would have escaped detection. Fortunately, how- 
 ever, the experiment was tried with a mixture of oxygen 
 and hydrogen gases, and still more fortunately, the in- 
 vestigation was conducted by Faraday. In this experi- 
 ment we find what we are in search of. The great 
 density of the platinum acts as an attracting molecular 
 force, exerting on the adjacent molecules of the gases a 
 pressure, by which a certain amount of condensation is 
 produced, sufficient to bring the approximated molecules 
 within the sphere of chemical action. One condition of 
 success was found necessary the surface of the metal 
 must be perfectly clean, which may be attributed to the 
 insulating effect of interposed dirt or grease. The delicacy 
 of the manipulation is shown by the fact that if the metal 
 
 G 
 
82 COHESION AND HEAT, MOLECULAR FOKCES. 
 
 be cleaned by friction and immediately plunged into the 
 mixed gases, the action will be retarded by the repulsive 
 influence of the heated metal. 
 
 The condensation of gases in porous bodies, such as 
 spongy platinum, charcoal, &c., is, we conceive, of the 
 same character, as is also that of the adhesion of solid 
 bodies to each other and to liquids : capillary attraction, 
 also endosmose and exosmose ascribed to osmotic force, 
 cell-force, and many other kind of influences, which 
 operate in complicated organic structures ; all such actions, 
 in as far as they are physical, may be referred to the 
 influence of cohesive force, diffused and extending beyond 
 the immediate limits of the molecules to which it more 
 immediately belongs. Such an influence, as from a com- 
 mon centre, draws towards itself and envelops adjacent 
 forces of the same kind, and by this aggregate force 
 produces effects which have always seemed marvellous 
 when compared with their apparently inadequate causes. 
 
 As yet, however, we only see this subject through a 
 glass darkly; we must await a farther accumulation of 
 knowledge thereon before we can expect to comprehend 
 it : but, in the case of heat, the correlative molecular 
 force, the antagonist of cohesion, we are better acquainted 
 with its modes of operation ; it is a qualitative, variable, 
 and diffusive force, and as such capable of being transferred 
 from one body to another. 
 
 Our knowledge, however, of even such a force, can, like 
 all other human learning, be only relative. The attribute 
 -of heat as a power is to expand bodies, which it effects by 
 adding to the repulsive force of molecules, and thus 
 causing them to recede farther npart from each other. The 
 
SPECIFIC MODES OF PHYSICAL POWERS. 83 
 
 amount of this expansive power we measure by making a 
 given body partaker of this action, the given body being 
 kept apart, and its degrees of expansion marked on a scale 
 by means of a contrivance called a thermometer. In 
 framing this scale some particular standard must be adopted 
 which is perfectly conventional. So that our knowledge 
 is only relative to this standard, and therefore the idea of 
 an absolute zero of heat, or of an absolute maximum, is a 
 vain pursuit, and contrary to the sound logical principle that 
 the maxima and minima of knowledge are not cognisable. 
 
 By the assistance of the thermometer we have been en- 
 abled to collect a vast amount of facts concerning the phe- 
 nomena of thermotic force. In the first place, we learn that 
 *iot only the different states of matter conduct heat in pecu- 
 liar manners, but at various rates, and that each kind of 
 substance has a particular conducting power. Thus, when 
 solids are exposed to heat they are affected thereby with 
 different degrees of rapidity, according to which they are 
 called good or bad conductors of heat ; amorphous solids con- 
 duct equally well in any direction, so that it matters not to 
 what part of the body the heat is applied; but this is not the 
 case with solids which have a regular structure. Senarmont 
 ascertained that crystals of the regular system also uni- 
 formly conduct heat in every direction, whilst those crystals 
 which do not belong thereto conduct best in directions 
 which are related to their optical axes. So likewise, ac- 
 cording to Delafive and Decandolle, woods conduct much 
 better with the grain than across it, that is, better in a 
 direction parallel to the fibres ; and, according to Dr. 
 Tyndall, more rapidly in a direction from the external 
 surface toward the centre than parallel with the ligneous 
 
 G 2 
 
84 COHESION AND HEAT, MOLECULAR FORCES. 
 
 rings ; all of which facts show that the action of heat in 
 solid bodies is variously modified by molecular arrange- 
 ments. It is evident that as these arrangements depend in 
 a great measure on the predominance of cohesion, this force 
 must offer greater opposition to its antagonist, heat, in cer- 
 tain directions ; that is, there will be lines of lesser and 
 greater resistance. This, however, is not the only modi- 
 fying circumstance; when a solid has parts varying in 
 degrees of cohesive tension, such in relation to each other 
 are different media through which force is always propagated 
 at different rates. It therefore follows that though, in 
 the lines of crystalline axes, the cohesive force would 
 oppose the strongest resistance to any structural change, 
 yet, on account of its uniformity and density, may more 
 readily transmit heat, on the principle of being a better 
 conductor. 
 
 But how do solid bodies conduct heat ? What is the 
 modus operandi of expansive force? is it by impulsive un- 
 dulations, by polar rotations, or how is the motion accom- 
 plished ? Now, in the case of radiant heat we know that 
 the transmission of the force is effected by a succession of 
 vibrating undulations ; and when these motions impinge on 
 the molecules of a solid the latter will also be moved; but 
 on account of the difference of the medium, the motions will 
 be greatly modified. The repulsive force will be absorbed 
 by the molecules of the solid, that is, enormously reduced 
 in the dimension of its effects or its motions, which instead 
 of being measurable will be inappreciably minute, but by 
 a continuance of the action will be ultimately manifested 
 as an expansion of the solid body. Now, if the entire 
 body expand, it can only be by the enlargement or expan- 
 
SPECIFIC MODES OF PHYSICAL POWERS. 85 
 
 sion of its individual molecules; the molecules that are 
 heated by the impinging undulations of radiant heat, by 
 the very act of expansion undergo minute motions which 
 are communicated to adjacent molecules, and thus propa- 
 gated after the same manner, though not with the same 
 immediate equalising result, as occurs through a series of 
 balls suspended in contact, when either extremity is struck. 
 And hence it is that the densest and most elastic solids are 
 the best conductors of heat; their structures are more uni- 
 form and their molecules more closely approximated than 
 solids of an opposite character, so that the minute expan- 
 sions are more rapidly transmitted. 
 
 The degree of expansion depends on the temperature, 
 that is, on the amount of repulsive force or heat present ; 
 and so, if on the other hand we can approximate the 
 molecules, that is, reduce the volume of the solid, a cer- 
 tain amount of heat on which the abstracted volume 
 depended will be set at liberty, and appear as an excess 
 or a plus state of heat, which will be diffused on adjacent 
 bodies. Thus a rod of iron by rapid hammering may be 
 made red hot, and indeed all malleable and ductile metals 
 by hammering, rolling, or punching, as in coining, become 
 heated, and increase in specific gravity, becoming at the 
 same time harder and more brittle ; but by strong heating 
 and subsequent slow cooling their original state will be 
 restored, that is, the effects of the compressing force, 
 applied in the direction and augmentation of cohesion, 
 will be overcome by the application of heat, so that the 
 molecules will return to their normal condition. Count 
 Rumford made some interesting observations on the heat 
 evolved during the boring of cannon, by which two gallons 
 
 G 3 
 
86 COHESION AND HEAT, MOLECULAR FORCES. 
 
 of water were made to boil in two hours and a half; but 
 Sir Humphry Davy performed a much more curious ex- 
 periment, by causing two pieces of ice to rub against each 
 other in vacua preserved at 32; sufficient heat was evolved 
 by the friction to melt the ice. 
 
 Hence it would appear that the action and reaction of 
 the physical powers are the joint causes of motion as well 
 as expansion, these only differing from each other as 
 effects in the different circumstances under which they 
 occur ; the one being the motion of a body or mass, and 
 the other of the molecules which constitute the sum and 
 substance of a body. In these cases moving force and 
 heat, being the plus or actuating energies, are commonly 
 regarded as the immediate causes of the body moving or 
 expanding; and as these are convertible effects, so their 
 causes are referred to the same force, repulsion. And 
 thus far we accept the common opinion of the identity and 
 mutual convertibility of forces ; for centrifugy, heat, and 
 electricity are, each and all, only modes or phases of the 
 universal physical force repulsion : but they must not be 
 confounded with their correlatives, their co-existing 
 antagonists, the various phases of attraction. 
 
 This analogy between motion and expansion, which now 
 seems to us so apparently self-evident, was long in being 
 clearly understood ; it is only of late years, through the 
 researches of Joule and Mayer, that much light has been 
 thrown on this interesting subject. Joule* ascertained 
 that the quantity of heat evolved by friction is in the ratio 
 of the moving force expended ; and that this is not de- 
 
 * Philpsophical Transactions for 1850. 
 
SPECIFIC MODES OF PHYSICAL POWERS. 87 
 
 pendent on the nature of the substances rubbed together, 
 but universally holds good. He found that one pound of 
 water was raised 1 Fahr. by the expenditure of a force 
 equal to 772 Ibs. raised one foot in height, communicated 
 to the water by means of a paddle-wheel revolving therein ; 
 when mercury was employed a force of 774 Ibs. was re- 
 quired to produce a like effect ; and when friction between 
 iron and cast iron was used, the equivalent force was found 
 to be 775 Ibs. These results so closely approximate, 
 that there is every reason to believe that the number of 
 foot-pounds of mechanical work expended is about 775 ; 
 a number which has been called Joule's Equivalent of a 
 Unit of Heat. 
 
 On this view of the subject it is easily apprehended 
 how molecular forces, whether those of the steam-engine 
 or of the animal frame, can function in the visible motions 
 of bodies, and how these again in their turn may return 
 to the condition of molecular movements, individually 
 inappreciable. We know that masses and molecules 
 present very different appearances; they are the maxima 
 and minima of matter; and so it might be expected that 
 their respective motions would afford a corresponding 
 difference of phenomena : when molecules are united we 
 have a mass, and when molecular expansions are conjoined 
 we have a visible body in motion, and so, conversely, the 
 mass and the motion may be broken up into indefinitely 
 minute molecules and expansions. 
 
 We have seen that the transmission of heat through 
 solids by conduction is very various, the force of repulsion 
 in these cases acting under great disadvantage ; in solids, 
 cohesion, the antagonist of heat, is in the ascendant, and 
 
 o 4 
 
88 COHESION AND HEAT, MOLECULAR FORCES. 
 
 therefore until this is equalised (which cannot be in 
 solids) the action of heat will produce some modification 
 quantum valeat ; but it cannot assume its normal mode of 
 action, an outward tendency opposite to that of gravity, 
 because the molecules are under the restraint of a superior 
 power. When, however, bodies are in the liquid state, 
 when the correlative forces, cohesion and heat, are in a 
 state of equilibrium, then the molecules are free to move ; 
 and when increased in volume, or expanded by heat, they 
 recede from the centre of gravity and ascend toward the 
 upper layers of the liquid, a movement which is facilitated 
 by the downward movement of the denser molecules 
 according to the law of gravity. This form of the propa- 
 gation of heat has been distinguished from conduction by 
 the name of convection. It follows from the nature of 
 this process that if heat be applied to the uppermost 
 surface of a liquid there will be no change of place, and 
 the heat will not be even gradually extended downward 
 by diffusion, if the liquid can freely evaporate. The 
 experiment usually adduced to prove that water does in 
 some small degree conduct downward, is objectionable; 
 in it, conduction by the vessel's sides has been guarded 
 against, but the radiation through the liquid remains ; and 
 the impinging rays on the bottom of the vessel must 
 produce some small effect, which to this extent cannot but 
 vitiate the result. 
 
 Liquids regularly expand by given increments of heat 
 until they approach a change of state, the boiling point ; 
 when various irregularities occur, but not so great as 
 those which attend the melting of solids. Gases, like 
 liquids, transmit heat by convection ; and since in their 
 
SPECIFIC MODES OF PHYSICAL POWERS. 89 
 
 constitution cohesion is completely overborne by repulsion, 
 they are free to respond to the action of heat, each 
 addition of which produces a corresponding equivalent of 
 expansion. The ratio of expansion for gases, and for 
 vapours when sufficiently remote from the boiling point 
 of their liquids, has been found to be about ^-^th part of 
 their volume for each degree of Fahrenheit. According 
 to the experiments of Regnault and Magnus, the co- 
 efficient of expansion is not rigidly uniform for all gases, 
 the expansion being greatest for those most readily con- 
 densible, whilst for the gases which have resisted all 
 efforts to liquefy them scarcely any appreciable difference 
 can be observed. This is as might have been expected, 
 cohesion being completely neutralised in the perfect gas, 
 but capable of producing some perturbations near the 
 point of liquefaction. 
 
 "When bodies change their state, as in liquefaction and 
 in vaporisation, it has been stated that definite quantities 
 of heat are combined with the molecules in a latent state, 
 which is the cause of the molecules being retained in 
 their new positions. And so, likewise, when the tempe- 
 rature of any body is changed without producing a dif- 
 ferent state, it is found that they all require different 
 amounts of heat to bring them to the same temperature, 
 that is, to the same relative degree of expansion ; which 
 could not well have been otherwise, for if each chemical 
 substance has a peculiar and definite atomic weight, dif- 
 ferent amounts of repulsive force must necessarily be 
 required to affect them in an equivalent manner. This 
 has been empirically arrived at in investigating the phe- 
 nomena of specific heats ; it was found that by multiply- 
 
90 COHESION AND HEAT, MOLECULAR FORCES. 
 
 ing the atomic weights of bodies into their respective 
 specific gravities, a near approximation to a constant num- 
 ber was obtained, which clearly indicated that the specific 
 heats were subject to some particular law. These inves- 
 tigations, however, are as yet in their infancy, so that a 
 satisfactory explanation cannot be expected ; but we think 
 that in the consideration of this and other physical 
 questions concerning molecular phenomena, the atomic 
 volumes, as well as atomic weights, will prove to be import- 
 ant data. 
 
 Expansion, as a general rule, denotes an increase of tem- 
 perature; but there are exceptions thereto, as in the notable 
 instance of ice and some other substances, which on solidi- 
 fying expand and become lighter, so as to float on their 
 respective liquids, showing that at a less temperature they 
 have a greater volume. Hence we learn, that whilst it is 
 the normal character of heat to expand bodies, this effect 
 may be also obtained by the reaction of its correlative force 
 cohesion, which by aggregating the molecules around par- 
 ticular axes, may produce an enlarged volume by peculiar 
 structural arrangements. This anomaly, then, which is 
 one of structure, interferes with the uniformity of relations 
 between specific heats and specific gravities : such compli- 
 cations are very perplexing, but they are invaluable, as 
 leading to a closer scrutiny of nature, and may ultimately 
 teach us the necessary compensations to be made in our 
 explanations. 
 
 The weights and volumes of bodies are continually 
 varying, and are the manifestations of the actions and 
 reactions of molecular forces. In gases (which, according 
 to our view, is the normal condition of matter), repulsion 
 
SPECIFIC MODES OF PHYSICAL POWERS. 91 
 
 or thermotic force is at a maximum, and any circumstances 
 which tend to alter their volume must cause a correspond- 
 ing alteration in the relative proportion of their molecular 
 forces. 
 
 When we exhaust the receiver of an air-pump, the tem- 
 perature within falls, which is the reverse of what happens 
 when air is compressed into a smaller volume : in the latter 
 case, the denser air being reduced in capacity, heat is set 
 free, which being in a plus or energetic state diffuses itself 
 on surrounding bodies, until equilibrium is restored; in 
 the former, the reduced quantity of air expands and fills 
 the entire receiver by its innate elasticity or repulsive 
 force, which was previously restrained by the ordinary 
 pressure of the atmosphere, and its specific heat undergoes 
 a corresponding increase, so that it absorbs heat from 
 around, in order to attain the common temperature. 
 
 At first sight this operation seems to be very puzzling ; 
 for one is apt to imagine that when air is rarefied, its in- 
 creased volume being attained, the process would seem to 
 be at an end ; but it is not so. The capability of an almost 
 indefinite expansion is the characteristic of the gaseous 
 state, and however much the gas may be compressed, this 
 property is ever present; and when the restraint is removed, 
 by its elasticity it increases in volume, its specific heat 
 being at the same time augmented; so that the degree of heat 
 which before maintained it at the surrounding temperature 
 is quite inadequate for this purpose, so that it becomes 
 colder, and therefore as a recipient of heat abstracts it from 
 adjacent bodies, according to the usual process of the 
 equalisation of heat between bodies at different tempera- 
 tures. We know that as we ascend in the air it becomes 
 
92 COHESION AND HEAT, MOLECULAR FORCES. 
 
 more rare, and the temperature gradually falls, so that in 
 the upper regions of the atmosphere, which are exceedingly 
 rarefied, an intense cold prevails. Some curious specula- 
 tions have been brought forward, particularly by Fourier, 
 concerning the temperature of space: the degree of cold is 
 supposed to be below any hitherto ascertained at the 
 earth's surface ; but even this is probably too high. Above 
 the perpetual snow line the atmosphere itself is so rare a 
 medium that the sun's rays pass freely through it without 
 heating, and the heat communicated from below by con- 
 vection must be quite inadequate to make any impression, 
 and even if it did would be dissipated faster by radiation 
 into space, which on account of its extreme rarity must 
 have an insatiable capacity for heat. 
 
 We know the amount of pressure in pounds-weight on 
 the atmosphere at the earth's surface ; and supposing the 
 height of the atmosphere to be fifty miles, its volume is 
 reduced by this pressure to about one-millionth part: 
 and from these data we may calculate what the density 
 would be at the centre of the earth, supposing the whole 
 of our planet to consist of air. This is not a vague and 
 objectless speculation : it may give a more definite notion 
 concerning the constitution of the comets, which seem to 
 be aeriform; and enable us to understand the Protean 
 changes which they undergo, one while expanding and at 
 another condensing, according to their position in relation 
 to denser bodies, by the attraction of which they suffer 
 compression when in their vicinity. 
 
 The extremes of rarefaction and of condensation which 
 gaseous bodies are capable of experiencing afford an end- 
 less variety of curious and useful applications ; these con- 
 
SPECIFIC MODES OF PHYSICAL POWERS. 93 
 
 ditions may be produced by purely physical forces, or by 
 chemical forces, or by both conjointly ; but our remarks 
 must now be restricted to the first mentioned. 
 
 Gaseous bodies, that is, gases and vapours, mutually 
 interpenetrate or become diffused through each other with 
 great facility; but the greater the difference in their 
 specific gravities, the greater the rapidity with which the 
 lighter gas is transfused. It is also a curious fact, first 
 made known by Dalton, that each gas is to another as 
 & vacuum, affected only by its own pressure ; and thus it 
 is that the independent existence of each causes the total 
 volume to be increased or diminished according to the 
 quantity of each gas present; so that whilst they are 
 equably diffused throughout each other, there is no actual 
 interpenetration. 
 
 It is for this reason that the vapour of water exists in 
 the atmosphere at all temperatures, even below that of 
 the freezing point of water ; the higher the temperature 
 the greater the weight of vapour in a given volume of air, 
 and consequently the greater the tension of the vapour; 
 and this goes on in a rapidly increasing progression, until 
 the temperature reaches 212, when the tension is equal 
 to the pressure of the atmosphere, and the water flies off 
 freely in the state of steam. It is worthy of remark that 
 the low vapour of water at 32 has a larger amount of 
 latent heat than the same weight of ordinary steam at 
 212. This curious fact was first made known by Watt, 
 who gave it the following expression : When latent heat 
 is added to sensible heat, the sum is a constant quantity 
 for the same vapour at all temperatures. This statement 
 is sufficiently correct for practical purposes, but not 
 
94 COHESION AND HEAT, MOLECULAR FORCES. 
 
 absolutely so ; for M. Eegnault has shown that the sum 
 increases as the temperature rises, by a constant quantity 
 of 0'305 for each degree of Fahrenheit. 
 
 As the pressure of the atmosphere varies, so does the 
 boiling point of liquids rise and fall ; and so, in accord- 
 ance therewith, liquids may be exposed to high tempera- 
 tures without being converted into vapour, provided they 
 are subjected to the requisite amount of pressure. And 
 the same holds good with the melting of solids; the 
 greater the pressure, the more heat is required for the 
 change of state. This is evidently owing to the resistance 
 of a force antagonistic to heat; a force which, acting in 
 the direction of cohesion, must favour its operation, and so 
 far opposes heat by requiring a larger amount of the latter 
 before it can become efficient. When liquids have been 
 thus superheated, on the sudden removal of the pressure 
 highly elastic vapour rushes out of the aperture with 
 great impetus ; and on this principle Perkins constructed 
 his steam-gun. The hand may be plunged into a stream 
 of high-pressure steam, as it escapes in a jet from the 
 boiler, without being injured ; a curious fact, and one 
 which remained long unexplained ; but now it is known 
 to belong to the same category as the cooling effect of 
 air suddenly rarefied during the exhaustion of the receiver 
 of an air-pump: the enlarged volume requires heat to 
 satisfy its increased capacity, which it absorbs rapidly 
 from adjacent bodies; and thus the hand in the above 
 case is for the instant cooled rather than heated. 
 
 Thus we learn that a liquid under great pressure may 
 be heated far above its boiling point without sustaining 
 a change of state : such a condition is tantamount to an 
 
SPECIFIC MODES OF PHYSICAL POWERS. 95 
 
 increase of cohesive force, for pressure acts in the direc- 
 tion opposite to that of repulsion. In connection with 
 this subject, M. Cagniard de la Tour has recorded some ex- 
 traordinary circumstances. It was long known that vapour 
 subjected to pressure is reduced to the liquid state by a 
 reaction which has just been explained; but it occurred 
 to him that, provided a sufficient space be allowed above 
 the liquid, the whole might be converted into high-pressure 
 vapour ; and he not only verified this conjecture, but also 
 ascertained the amount of pressure required for the pur- 
 pose. Alcohol, with an empty space equal only to one 
 and a-half time its volume, was entirely converted into 
 vapour at a temperature of 404 and a pressure of 119 
 atmosptieres. Water required four times its volume, and 
 such a high degree of heat and pressure that the glass tube 
 was decomposed and disintegrated by the steam. 
 
 Startling, however, as these experiments are, they are 
 perfectly consistent with our knowledge : we can conceive 
 of no limit in the degree of compression of highly heated 
 vapours than the volume of the liquid state itself at a cor- 
 responding temperature. At this point it would be a 
 superheated liquid, but should it become somewhat more 
 expanded, it would become high-pressure vapour of the 
 greatest possible density. 
 
 Our attention has been for some time engaged in the 
 consideration of that branch of molecular physics in which 
 repulsive force, as heat, has been in the ascendant ; a force 
 so energetic and continually varying, that the natural 
 history view, or outward descriptions of its objects, are 
 lost sight of in the absorbing interest of searching for the 
 causes of its physical phenomena ; and we have seen that, 
 
86 COHESION AND HEAT, MOLECULAR FORCES. 
 
 although heat is the predominant, it is not the sole cause, 
 and that we cannot arrive at satisfactory explanations 
 without taking into account the actions and reactions of 
 both the correlative causes, cohesion and heat ; the one 
 tending to condensation, the other to rarefaction. We 
 must now, however, take a brief view of the other branch 
 of the science, in which cohesion is in the ascendant, and 
 we shall find that it has a very different character : this 
 force tends to a state of rest in rigid solidity, and presents 
 an aspect which calls more for description and classifica- 
 tion, and much less for physical considerations ; and there- 
 fore its objects, if less interesting, are capable of being 
 better known. 
 
 When molecular attraction or cohesion predominates in 
 bodies, it functions in the production of those morphic 
 forms of matter called crystals. In crystals the molecules 
 are symmetrically arranged around one or more axes of 
 aggregation ; and the nature of this arrangement seems in 
 a great measure to depend on the primary forms which 
 the molecules of each chemical element possess. Each 
 molecule, then, according to its crystallographic system, 
 has definite poles, by which it is united and held together 
 with other molecules, according to the laws of polarity. 
 Now, in consequence of this axial arrangement of the 
 molecules, a body will be variously affected by extraneous 
 physical forces, according to the direction of their appli- 
 cation, the degree of fixidity of the molecular poles on 
 different axes offering a corresponding resistance. This 
 subject has of late years been much studied, as has also 
 the determination of all possible forms by increments and 
 decrements on certain planes and angles, which is treated 
 
SPECIFIC MODES OP PHYSICAL POWERS. 97 
 
 of under " Crystallography," a subdivision of this branch 
 of Physics. 
 
 Very different substances may crystallise in the same 
 forms, but they are not called isomorphous ; this term 
 being restricted to similarity of form, when conjoined with 
 analogous chemical constitution. Different substances 
 having the same form may perfectly resemble each other, 
 when they belong to the regular or tessular system ; but 
 when they belong to other systems, their forms are not 
 exactly similar, for a measurement of the angles of prisms 
 and octahedra shows considerable differences in the length 
 of their axes ; and in the case of two oblique systems, 
 guch crystals may appear to be very like, but their axes 
 are variously inclined toward each other. Mitscherlich, 
 to whom we are indebted for much information on this 
 subject, has been led to conclude, that whilst crystalline 
 forms "depend on a physical grouping, and not on the 
 chemical nature of the atoms, yet that the same number 
 of atoms of analogous chemical substances, when com- 
 bined, always produce the same crystalline form. "If 
 Mitscherlich's law," observes Professor Miller *, " be con- 
 fined to compound bodies, the facts which have been 
 supposed to militate against it will prove a remarkable 
 corroboration of its truth, as they show that the number 
 and collocation of the atoms may overcome the tendency 
 of some elementary components to assume different forms. 
 It also shows that it is unsafe to infer isomorphism in the 
 elements, simply from the occurrence of isomorphism in 
 the compounds which they form." 
 
 * Elements of Chemistry, vol. i. p. 109. 
 H 
 
98 COHESION AND HEAT, MOLECULAR FORCES. 
 
 We are not as yet in a position to determine, a priori, 
 what forms will result from the combinations of given 
 elementary forms ; though this would seem not to tran- 
 scend the sphere of geometry, nor yet to ascertain why 
 the molecules of some chemical elements have the same 
 crystalline forms ; whilst the number of material atoms 
 in each chemical atom is so disproportionate, as in the 
 case of carbon and of gold, which crystallise similarly, 
 though the weight of the latter is sixteen times greater 
 than that of the former. But doubtless some law of 
 physical aggregation is followed in these cases ; and if the 
 molecular form of each element were determined, applied 
 geometry ought to give all the possible combinations, 
 provided the volumes of such elements remained unaltered 
 during aggregation ; for of course a change, in this respect, 
 would produce a corresponding disturbance. There is, 
 indeed, every reason to believe that such changes do occur 
 when the weight of the element is considerable, that is, 
 is composed of many material atoms, for in such cases 
 condensations around common centres, being various, 
 would favour the production of different crystalline forms. 
 
 That such a condition is not only possible but probable, 
 is demonstrated by the well-known phenomenon, dimor- 
 phism, which consists in the same substance crystallising 
 not only in many congenerous forms, but also in forms 
 which are geometrically incompatible, belonging to dif- 
 ferent systems. This is not a chemical change, but one 
 purely physical ; though the new arrangement may be 
 such as to facilitate chemical affinities which were not 
 possible in the original condition. To give an instance of 
 dimorphism. Sulphur is found native in oblique rhombic 
 
SPECIFIC MODES OF PHYSICAL POWERS. 99 
 
 octahedrons ; and these crystals are comparatively hard, 
 do not readily change on exposure to the air, and have a 
 density of 2 -05; but when these crystals are melted and 
 slowly cooled, prismatic forms are obtained, which belong 
 to the fifth or oblique system, whilst the original octa- 
 hedrons belong to the fourth, or prismatic system of 
 crystals. The density of the prismatic crystals is only 
 1 -98, and they are not permanent in the air, but soon lose 
 their transparency ; and although they retain for awhile 
 their prismatic form, the coherence of their molecules is 
 so slight, that when pressed they easily crumble into 
 powder, which under the microscope is found to consist of 
 minute rhombic octahedra. 
 
 The following may be the explanation of these changes. 
 The octahedral form may be the normal crystal of sulphur, 
 that is, of this chemical element, that in which cohesion 
 is exerted with its fullest force ; and hence a correspond- 
 ing degree of hardness, density, and persistency. In the 
 prismatic crystals, however, the molecules arrange them- 
 selves differently during the gradual recovery of their 
 cohesion from the melted state, by which difference of 
 form they acquire a greater volume, and consequently 
 diminished density ; and this new arrangement being a 
 state of instability, the molecules are capable of regaining 
 the normal state, in which their centres of gravity are in 
 firmer positions. It is possible that the prismatic crystals 
 may be aggregations of the octahedra, but we are inclined 
 to think that the change is much more fundamental, that 
 these crystals are different arrangements of the material 
 atoms which form the body or basic power of the chemical 
 element sulphur. 
 
 H 2 
 
100 COHESION AND HEAT, MOLECULAR FORCES. 
 
 Many facts concerning dimorphism and trimorphism 
 might be adduced, all pointing in the same direction and 
 capable of a similar explanation ; all depending on co- 
 hesion, and varying as this force is modified by the relative 
 proportions of repulsive force in the substances. Indeed, 
 what is commonly called the three states of matter is, in 
 fact, but an example of trimorphism, in which the mole- 
 cules of the same substance are arranged in three different 
 forms, according to the proportions of their correlative 
 forces cohesion and heat. 
 
 Dimorphism, trimorphism, and similar terms, however, 
 are more correctly restricted to variations of crystalline 
 forms; and the term allotropy has been employed to 
 denote those physical changes which bodies are capable 
 of undergoing without affecting their chemical composi- 
 tions. The subject of allotropy has of late years attracted 
 much attention ; and it bids fair to throw much light on 
 several phenomena which have hitherto been involved in 
 much mystery. The allotropic states of carbon, sulphur, 
 and phosphorus have been carefully investigated, and they 
 may, we think, be all explained by the relative condition 
 of molecular forces ; the phenomena of altered density 
 and hardness have been already alluded to, but those 
 arising from the influence of light and electricity will be 
 noticed hereafter; since, however, these are only modes 
 of physical forces, it might be expected that they would 
 undergo analogous variations according to the molecular 
 structure of bodies. 
 
 In addition to the physical changes which allotropy 
 presents, it has been observed that though the substances 
 have the same composition, they do not comport them- 
 
SPECIFIC MODES OF PHYSICAL POWERS. 101 
 
 selves in the same manner when subjected to chemical 
 reagents. This, however, cannot be adduced in favour of 
 a transmutation of bodies ; it is only one of the many 
 instances in which affinities are modified by physical 
 conditions. Chemical elements have a definite and in- 
 destructible constitution, and combine together in definite 
 proportions ; but there is a sphere of action within which 
 only chemical forces can operate, and physical forces 
 greatly influence this condition. Connected with allo- 
 tropic changes, there is one circumstance which must not 
 be lightly passed over ; it is an important fact, and may, 
 if followed up, lead to important results ; we allude to 
 the capacity of a solid body to render heat latent, as in 
 the changes of state by liquefaction and vaporisation, as 
 occurs in the production of Schrotter's phosphorus. The 
 varied appearances of sulphur, when melted at different 
 temperatures, may be found to give similar indications ; 
 indeed, whenever the molecules of bodies are retained in 
 new positions force must be employed in producing such 
 a result ; and this force is absorbed in the operation, and 
 thus becomes neutral or latent, but is again manifested 
 when the body reverts to its former state. 
 
 There can be little doubt that many substances will be 
 found to be susceptible of allotropic modifications, as our 
 researches are extended ; and, indeed, a large body of 
 scattered facts seem to belong to this category. Thus, 
 the altered condition of artillery, after frequent discharges, 
 and of metals long exposed to friction, to incessant vibra- 
 tions or percussions ; of metals at different temperatures, 
 as zinc, which is one while so malleable as to be rolled 
 into sheets, and at another so brittle as to be easily 
 
102 COHESION AND HEAT, MOLECULAR FORCES. 
 
 pounded ; and so likewise many metals, glass, earthen- 
 ware, and other substances, if rapidly cooled from a state 
 of fusion are hard and brittle, but slowly cooled, or 
 annealed, they lose this property; all these and many 
 other similar facts are kinds of allotropy, that is, meta- 
 morphoses of molecular arrangements. 
 
 All these cases of allotropy refer to solids ; our know- 
 ledge on this subject in regard to liquids is very limited. 
 The varied appearances of melted sulphur at different 
 temperatures have been already alluded to, as also the 
 anomaly of water expanding before it reaches the melting 
 point. It is not surprising that liquids as well as solids 
 should experience allotropic changes; but it is very 
 curious that we should find notable instances of such 
 changes in gases, the great elasticity of which seems to be 
 opposed to such alterations. It is, however, now very 
 generally admitted that ozone is allotropic oxygen ; and it 
 is very probable that those gases which acquire energy by 
 exposure to light, are rendered allotropic by actinism; the 
 altered condition of gases, which are condensed by the con- 
 tact of solid bodies, may possibly undergo a similar change 
 beyond that of a reduction of volume. 
 
 In thus endeavouring to reduce all our knowledge 
 concerning the aggregation and expansion of molecular 
 bodies under the general head of Micronomy, or Molecular 
 Physics, we do not refuse the subdivision of this science 
 into many subordinate branches. It may be well to 
 arrange the facts, concerning solids, liquids, and gases, 
 under distinct heads, and, provided each of these is con- 
 sidered, both phenomenally and causally, the constituent 
 forces determined, and the motions resulting from all the 
 
SPECIFIC MODES OF PHYSICAL POWERS. 103 
 
 changes in the relations of these forces, then each may 
 form a subordinate science ; but we protest against taking 
 either force in a plus state, and treating of its actions as a 
 proper science. 
 
 The various subjects connected with molecular physics 
 are too numerous to be noticed in this general view ; but, 
 from what has been already stated, it will be readily 
 understood how we should treat these subjects. 
 
 Before turning to a fresh topic, let us gather together, 
 as we proceed, a summary of the natural dualisms which 
 have been considered, and also of their dependant 
 sciences. 
 Dualism of Physical Powers : 
 
 Attraction + Repulsion = Matter or Physical Substance. 
 
 Phase of Physical Powers as Central Forces : 
 Gravity -f Centrifugy = Celestial Masses or Stars. 
 
 Phase of Physical Powers as Molecular Forces : 
 Cohesion + Heat = Molecules. 
 
 The science of Physical Substance is Physics ; that of 
 the Stars, Celestial Physics, or Astronomy ; and that of 
 Molecules, Molecular Physics, or Micronomy ; and the 
 variable phenomena of which these sciences treat are all 
 some kinds of motion. 
 
 H 4 
 
104 
 
 CHAP. IV. 
 
 SOUND AND LIGHT, MOLECULAR AND ETHERIAL 
 UNDULATIONS. 
 
 Undulations of Material Bodies. The Medium of transmitting Force. 
 The Difference between Sound-waves and Light- waves. Light not 
 related to Heat and Electricity as Modes of the same Force. What 
 is Light? Sir John Herschel's Answer to this Question. Light, 
 like all other Motions, a Composition of Forces. According to 
 Comte, Light is something sui generis : heterogeneous to Motion. 
 All Undulations are not audible and visible. Limitation of the 
 Scale of Sound and Light Perceptions. The Analogies between 
 Sound and Light. The Origin and Constitution of Sound. Its 
 various Media: that of Air immediately concerned in Hearing. 
 The Sound-wave a Dualism of Forces. The Composition of Light 
 not yet understood. The Colours of the Prismatic Spectrum. 
 Distributing of Heat-rays and of Photographic -rays in the Spectrum. 
 These two kinds of Rays arranged in an inverse Ratio. Radiant 
 Heat and Actinism the component Forces of Light- waves. Heat 
 the Cause or Primum-mobile of Light. Actinism not a chemical 
 Force, but a Mode of Physical Attraction. Conclusion. 
 
 THE motions of natural bodies are caused by the actions 
 and reactions of the physical powers, attraction and re- 
 pulsion ; and it is by these phenomena alone that the 
 physical powers are manifested ; and, as these phenomena 
 assume different aspects according to the kind of natural 
 bodies with which they are associated, so the physical 
 powers, as objects of knowledge, present themselves 
 
MOLECULAR AND ETHERIAL UNDULATIONS 105 
 
 under corresponding phases or modifications. Thus, 
 when the motions of the celestial orbs are studied, the 
 powers of attraction and repulsion are manifested as 
 gravitation and centrifugal force; but when we turn 
 from the distinct and measurable motions of the stars to 
 the minute and individually inappreciable motions of mole- 
 cules, the physical powers assume a very different aspect, 
 and we distinguish them accordingly as cohesion and 
 heat; still they are, like the astronomical forces, phases 
 of the same universal powers, attraction and repulsion. 
 
 The phenomena resulting from the action and reaction 
 of astronomical and molecular forces would, at first sight, 
 seem to exhaust all possible motions of material bodies; 
 and so they do, as far as regards the continuous change of 
 place in space ; and as such motions are, in relation to 
 each other, the maxima and minima of all continuous 
 changes of place, they form a universal, which ought to 
 be capable of affording one common science of physics. 
 There is, however, a great convenience in treating of 
 astronomy and micronomy as distinct sciences ; and as 
 this method is firmly established, it would be a needless 
 innovation to propose their conjunction ; but it is not 
 improbable that it may be attempted, should a generalising 
 spirit become in vogue. 
 
 Passing, then, from the consideration of progressive mo- 
 tions, of rotation and revolution, and of contraction and 
 expansion, we proceed to inquire into those limited 
 motions of successive repetitions, which vibrate forward 
 and backward, which kind of oscillations are known as 
 undulations. All bodies seem to be capable of undergoing 
 such movements ; therefore, they are universal ; and 
 
106 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 since all motions are caused by the universal physical 
 powers, undulations must necessarily be attributed to 
 the operation of some peculiar modes or phases of these 
 powers. 
 
 When the various kinds of undulations are attentively 
 considered, it will be perceived that they belong to two 
 great heads, which comprise all these phenomena : the 
 one includes the vibrations of all material molecules ; 
 the other, those of the atoms of that subtile fluid, the 
 ether of space. Undulations may also be divided into 
 such as are manifested to the consciousness, as sound and 
 light ; these would comprise the greater part, and by far 
 the most important, but not the whole of these pheno- 
 mena. 
 
 Undulations are, therefore, the means by which force is 
 transmitted through various media ; and as they pass from 
 one kind of medium to another, they give rise to a diver- 
 sity of actions and reactions ; thus, we note the velocity 
 with which they transmit their exciting force, its direction, 
 and the varying intensity of its energy; the dimensions 
 and frequency of the undulations are also interesting 
 objects of observation. If it were not for sound and light, 
 we should be ignorant of most things, and of the events 
 which are passing around us, for it is through their agency 
 chiefly that matter and mind are brought into communi- 
 cation ; so that this subject is one of the most important 
 that can engage our contemplations. 
 
 Sound, as the perception of sonorous undulations, seems 
 to have been clearly apprehended; but the notion con- 
 cerning light is still very vague. Light is no longer 
 indeed regarded as a corpuscular entity, but still there is 
 
MANIFESTED AS SOUND AND LIGHT. 107 
 
 a lingering tendency to view it as something real in itself; 
 thus, it is commonly spoken of as a peculiar kind of force, 
 and as such placed in the same category as heat and 
 electricity. And not only so, but a strange notion con- 
 cerning it has of late been current, and which is said to 
 have originated with George Stephenson: viz. that the 
 light of our gas and coal-fires is a re-manifestation of the 
 sun-light of remote ages, which had been absorbed and 
 fixed by primeval vegetation; a notion which virtually 
 reasserts the corpuscular theory, which has been repu- 
 diated by modern science. Would any one maintain 
 that the musical sounds which now charm our ears, are 
 identically the same as those which delighted the antedi- 
 luvian world ? As sounds, they are indeed similar vibra- 
 tions, but they are not sounds evoked from a dormant 
 state. Perhaps we lay too much stress on this point, but 
 we have done so, because light is regarded by many as a 
 specific force, and as such, capable of existing in a latent 
 state, according to the above fanciful conjecture. 
 
 All, however, are not of this opinion : " The question," 
 says Sir John Herschel*, " What becomes of light? merges 
 itself into the more general one, What becomes of motion ? 
 And the answer on dynamical principles is, that it con- 
 tinues for ever. No motion is, strictly speaking, annihi- 
 lated, but it may be divided, and the divided parts made 
 to oppose, and in effect destroy each other. A body 
 struck, however perfectly elastic, vibrates for a time, and 
 then appears to sink into its original repose ; but this 
 
 * On the Absorption of Light by Coloured Media, As quoted in 
 the Connexion of the Physical Sciences, p. 197. 
 
108 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 apparent rest is nothing else than a state of subdivided 
 and mutually destroying motions, in which every molecule 
 continues to be agitated by an indefinite multitude of 
 internally reflected waves, propagated in every possible 
 direction, from every point in its surface, on which they 
 successively impinge." This is well stated, and is sound 
 doctrine; we only differ from it as to the manner in 
 which the fact is expressed. We see in a motion only a 
 composition of forces, of which one is in a plus state ; 
 when this is diffused by innumerable subdivisions, and 
 a state of equilibrium is restored, the motion is appa- 
 rently destroyed, whilst the forces constituting the equi- 
 librium still exist and are indestructible, though, on 
 account of their equipollence, they cannot function in 
 visible motion. 
 
 The luminous and sonorous vibrations are only particular 
 forms of material movements, which as physical pheno- 
 mena occur in nature, whether they are perceived by 
 sentient creatures or not : they are the phenomenal ap- 
 pearances of natural dualisms or composition of forces, 
 which are co-existent and opposite. 
 
 The sciences of light and sound, optics and acoustics, 
 have been rightly conceived and constructed ; and each of 
 them has, in common with all true sciences, two logical 
 branches, the phenomenal and the causal. The former 
 branch of each science has been carefully examined and 
 arranged: so that we need not dwell thereon; but the 
 causal or physical branch, more especially that of optics, is 
 as yet imperfect; and will require our more particular 
 attention. 
 
 This view of the subject is contrary to the positive 
 
MANIFESTED AS SOUND AND LIGHT. 109 
 
 philosophy, and has been condemned by Comte.* " Phy- 
 sicists," he says, " must abstain from fancifully connecting 
 the phenomena of light and those of motion : the suppo- 
 sition, now become classical, that sound and colours are 
 radically alike, is a wild imagination. It is much better 
 to leave such a pursuit of scientific unity, and to admit 
 that the categories of heterogeneous phenomena are more 
 numerous than a vicious systematising tendency would 
 suppose. The phenomena of light will always constitute a 
 category sui generis, necessarily irreducible to any other: 
 a light will ever be heterogeneous to a motion or a sound." 
 Comte admits the connection of sound with the vibrations 
 of material media ; and also the direct application of 
 rational mechanics to explain its phenomena : and had he 
 realised the idea, now so generally accepted, that the ether 
 of space is an elastic material fluid, he would, perhaps, 
 have acknowledged the analogy between sonorous and 
 luminous undulations. These vibrations do, indeed, differ 
 from each other in their respective lengths, velocities, and 
 other particulars : but all such differences may be fairly 
 referred to the diverse characters of the media, the one 
 ponderable and the other imponderable, which constitute 
 the fields of their respective operations. 
 
 In treating of acoustics and optics, it must be remem- 
 bered that these sciences do not deal with all possible 
 molecular and etherial vibrations ; but only with those 
 which affect the organs of hearing and of sight, as sound 
 and light. This limitation is a defect, in regard only to 
 the physical motions ; but, as regards audible and visible 
 
 * Positive Philosophy, vol. i. p. 269. 
 
110 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 vibrations, it is provided for by the special definitions of 
 these sciences. It is well known that the vibrations of 
 bodies do not always produce sounds that can be perceived 
 by the human ear ; and such inaudible vibrations occur 
 beyond both extremes of the musical scale : some being 
 so slow and grave, and others so rapid and acute, that they 
 cannot be heard ; though it is probable that such make 
 conscious impressions on the organs of other creatures. 
 At all events, this holds good with corresponding etherial 
 vibrations; for some nocturnal animals evidently see 
 distinctly, when objects are to us barely visible; and 
 others can endure such a brilliant light, as would produce 
 in us temporary blindness. 
 
 In the case of light, as compared with that of sound, 
 the scale of perceptions is very limited, which is not sur- 
 prising, when the inconceivable rapidity of the luminous 
 vibrations are taken into account ; a condition not favour- 
 able to very nice discriminations ; still though there is 
 but one octave of colours in place of the many octaves of 
 musical sounds ; the analogy between the different kinds 
 of vibrations is very close. For if the notes of an octave 
 be simultaneously struck, there is a distinct musical sound, 
 which comprises, and may be separated into its component 
 notes : and so, pure white light may be subdivided into 
 the colours of the spectrum ; which may be reunited so as 
 to restore the white light again. And in both cases, the 
 notes and the colours only differ from each other in the 
 number and length of the vibrations of their respective 
 media. The ratios of the vibrations, both of harmonic 
 sounds and of colours, are also analogous : for as there are 
 in any octave harmonics of the fundamental note, vibrating 
 
MANIFESTED AS SOUND AND LIGHT. Ill 
 
 in simple relations to produce a concord ; so in the spec- 
 trum there are three primary colours, which are distinctly 
 defined, and which by their union give clear white light. 
 Musical notes struck in succession can be distinctly heard ; 
 because, though each differs in the number of its vibrations, 
 sound of all kinds travels at a uniform speed in the same 
 medium ; and are therefore heard in the order of their 
 production at any distance : if it were otherwise music 
 would be impossible. And so in the case of colours ; 
 though the vibrations of each also differ, their respective 
 rays all meet the eye at the same instant. As regards 
 degrees of intensity, sonorous and luminous vibrations 
 are similarly circumstanced; the volume of sound, and 
 the brilliancy of light/ depend on the amplitude of the 
 vibrations ; a strong force producing corresponding action 
 on the material content of either medium. So likewise 
 the pitch of musical notes, and the body or tone of colours, 
 vary with the rapidity of the vibrations ; the quality of 
 both sensations depending on the molecular constitution 
 of the bodies from which the undulations are reflected. 
 
 In short, both sound and light are manifested to the 
 consciousness by impressions made on the respective 
 organs of sense by physical impulses communicated 
 through the undulations of the appropriate medium ; and 
 therefore we find, as might be expected, that the vibra- 
 tions of both kinds are similarly constituted, and that 
 they follow similar laws of action, though the precise 
 analogy may not be, in all cases, easy of determination. 
 Let us then, in the first instance, consider the constitution 
 of sonorous undulations, in order to determine the nature 
 of the forces which compose the dualism, sound ; which is, 
 
112 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 as already stated, the phenomenal appearance of a compo- 
 sition of forces; and also to determine the manner in which 
 these forces act and react on each other : and then, if 
 there be truly an analogy between sound and light, the 
 knowledge of the nature of sound ought to enable us to 
 answer the question, What is light ? 
 
 In the case of sound, the vibrations are occasioned by 
 any sudden impulse, such as a blow, an explosion, or the 
 like, communicated to substances which possess some 
 degree of elasticity. The active or aggressive force, 
 which disturbs the equilibrium of the medium, urges a 
 certain number of molecules forward in the direction of 
 the force, thereby exerting a pressure which produces 
 a certain amount of condensation, according to the in- 
 tensity of the force ; this condensed portion of the medium 
 becomes, in its turn, virtually a force acting on the mole- 
 cules immediately before it, on account of its plus or 
 excited state, and when relieved by diffusion or trans- 
 mission from this condition, the correlative force of the 
 dualistic medium recovers from the constraint: and its 
 liberated energy exerts itself as elasticity, and reacts in 
 the opposite direction, causing an expansion or rarefaction 
 of those molecules which had been previously condensed. 
 This action and reaction, being confined to a circumscribed 
 portion of the medium, produce an oscillating movement 
 forward and backward, making a complete vibration. 
 Of course, all these movements greatly vary according 
 to the medium in which they take place, and according 
 to the part of the medium, whether its surface or its 
 substance, on which they operate ; but under whatever 
 circumstances they occur, these movements are all fun- 
 
:\!AXIFESTED AS SOUND AND LIGHT. 113 
 
 damentally the same, the forms of the phenomena may 
 be those of condensation and rarefaction, of depressions 
 and elevations, and the like; all of which are reducible 
 to the simple expression of action and reaction, which 
 characterise the functions of co-existing and opposite 
 forces, in all phenomena. 
 
 In this statement, we have referred to no particular 
 medium for the sonorous vibrations; but, practically, 
 the air is always the medium through which direct com- 
 munication takes place with the auditory nerves ; though 
 it often happens that the air is not the body which 
 primarily vibrated. The initiatory vibrations may be 
 transmitted along various kinds of substances for the 
 greater portion of the distance between the place of 
 excitement ; but before they can become audible as 
 sounds, they must be propagated to the air contained 
 in the organ of hearing: so that the air is either originally, 
 or ultimately, the medium of communication. Although 
 air, on account of its great elasticity, and of its suscep- 
 tibility of responding to the gentlest impulses, is beauti- 
 fully adapted for the transmission of sounds, yet these 
 travel much slower in air than in many other media ; 
 thus the velocity of sound in air is 1090 feet per second, 
 in water four times as much, and in iron it is more than 
 sixteen times that in air; indeed it has likewise been found 
 to vary in air itself according to its density. The degree 
 of loudness also varies as the density of the air, so that no 
 sound follows an impact in an exhausted receiver. 
 
 We have already repeatedly stated that a force of any 
 kind, which approximates the molecules of bodies by con- 
 densation, acts in the direction of attraction, and thus 
 
 I 
 
114 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 acting must counteract the energy of the co-existing and 
 opposite force, repulsion ; and, in so far as it thus acts, 
 it balances or renders passive an equivalent of the latter 
 force, which however, though rendered latent, is not de- 
 stroyed, and immediately restores the original volume 
 on the removal of the aggressive force. And this modus 
 operandi of correlative forces is, we think, in accordance 
 with the phenomena of vibrations; and if so, we find 
 in these peculiar motions a dualism of forces, analogous 
 to that of all the other physical phenomena which have 
 previously engaged our attention. Indeed this must 
 necessarily follow, or our position cannot be maintained, 
 that all natural bodies, whatever be their varied condition, 
 are dualisms of forces ; that, in as far as such bodies are 
 material, their forces are some modes or other of the 
 universal physical forces, attraction and repulsion, all of 
 which function only in some forms of motion. According 
 to this view of the subject, sonorous vibrations are peculiar 
 motions of matter, and consequently their constituent 
 forces must be some dualism of correlative physical forces, 
 that is, of forces which co-exist in this particular phe- 
 nomenon. The correlative forces of a sonorous vibration 
 are evidently an impulsive compressing force and a re- 
 acting elasticity, by the concurrence of which the dualism 
 is produced. Perhaps it may be as well, in order to 
 mark more clearly our meaning, to denote the former 
 force by a special name, and temporarily for this purpose 
 it may be designated as epipallism, an impulsive force 
 causing vibrations, and its correlative force may be called 
 elasticity, with which we are already familiar. But call 
 them what you will, they are distinct phases of physical 
 
MANIFESTED AS SOUND AND LIGHT. 115 
 
 forces, co-existent and antagonistic, which is all that is 
 requisite for forces to be able to act and react, and so 
 produce corresponding phenomena; and we therefore sym- 
 bolise this correlation as 
 
 Epipallism + elasticity = sonorous vibration or sound. 
 
 Now, let us turn our attention to luminous vibrations, 
 an inquiry of a more delicate character, and one concern- 
 ing which we have much yet to learn; so that the subject 
 must be approached more cautiously. 
 
 Etherial vibrations produce on the organ of sight the 
 sensation called light; and the science or systematic 
 knowledge of light is called Optics. The phenomena of 
 light, as to their outness or external aspect, have been 
 extensively and successfully investigated : a vast fund of 
 very curious and interesting facts has been accumulated, 
 concerning the reflection, refraction, interference, polarisa- 
 tion, and other conditions of the luminous rays ; but we 
 need not enter into these details, as they have already 
 been well described by others. But, concerning the 
 constitution of light, what it is essentially in itself, what 
 are its correlative forces, and the nature of the internal 
 actions and reactions which these produce, we have yet 
 much to learn ; and it is, therefore, to the causal or dy- 
 namical branch of optics that our enquiry will be chiefly 
 directed, in the hope of deriving some aid from the princi- 
 ples of our system. 
 
 According to the emission theory of Newton, light is a 
 corpuscular body, consisting of particles of impalpable 
 tenuity which are incessantly radiating from luminous 
 bodies with a velocity of about 198,000 miles in a second 
 
 1 2 
 
116 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 of time. According to the undulatory theory, there is 
 throughout space, an ether, or exceedingly elastic fluid, 
 capable of being thrown into undulations, that propagate 
 themselves with astonishing swiftness: such undulations 
 are produced by luminous bodies, just as the air is thrown 
 into pulsations by sonorous bodies ; and, as these undula- 
 tions, or light-waves, reach the eye, they cause the sensa- 
 tion of light. The latter theory is satisfactory as far as it 
 goes; but it does not, like that of Newton, tell us what 
 light is, it only informs us that when issuing from a 
 luminous body it is propagated through space by undula- 
 tions. 
 
 In the case of sound-waves, we know that they have 
 their origin in the exercise of some physical force ; and 
 those who regard light as a specific force, like that of 
 heat or electricity, may suppose that it is this force 
 emanating from luminous bodies which occasions the 
 light-waves. It is, however, evident that this does not 
 answer the question, What is light? For a luminous body 
 is already in a state of luminous undulation ; it only differs 
 from ether, and our atmosphere, in being a different 
 medium, intensely agitated by vibrating motions, which 
 are being diffused on all sides from a common centre by 
 radiation. What we want to know is, when we objectify a 
 light- wave, its internal composition; what is it in itself? 
 We know it is a peculiar motion, and every motion is a 
 composition of forces ; it cannot be a single force, for in 
 nature there is no such thing, and if there were, would be 
 unknowable. Light is, therefore, a natural dualism, and 
 as such must consist of correlative forces; the object of 
 our search then is clearly defined, we must endeavour to 
 
MANIFESTED AS SOUND AND LIGHT. 117 
 
 ascertain what these forces are, which conjoined make the 
 correlation, light. 
 
 Newton, pondering on the reason of the uniform series 
 of colours in the rainbow, and in the prismatic spectrum, 
 saw clearly that they were in some way related to pure 
 white light; and he ultimately arrived at the conclusion, 
 that light is a compound of the prismatic colours ; and 
 this conjecture was confirmed by the reproduction of white 
 light, when by means of lenses he gathered all these colours 
 together into one focus. The result, having the Baconian 
 criterion of an experimentum crucis, for a time gave the 
 corpuscular theory of light the preponderance in public 
 estimation ; but the undulatory theory has since explained 
 the phenomenon in a satisfactory manner ; the vibrations 
 of the different coloured lights have been measured, and 
 been found to vary in magnitude from about 37,640 to 
 59,750 within the length of an inch, and in velocity from 
 458 to 727 billions of pulsations per second; the lower 
 part of each series beginning at the red colour, and the 
 higher terminating in the violet. If, then, the various 
 prismatic colours be light-waves, only differing from each 
 other in the length and velocity of their motions, they 
 are not individual and independent entities, but only 
 the maxima and minima conditions of the self-same thing: 
 these modifications of the light-wave, being dissimilar 
 in their properties, produce corresponding variations in 
 their physical impressions on the retina of the eye, and 
 are, consequently, distinguished in sensation as particular 
 colours. 
 
 But then comes an important consideration, How are 
 these colours presented in a regular series ? And how comes 
 
 I 3 
 
118 MOLECULAR AND ETHEKIAL UNDULATIONS 
 
 it to pass, that many substances have specific colours, 
 which they permanently retain under the same circum- 
 stances? These points cannot, as yet, be perfectly ex- 
 plained : but in the mean time it is not difficult to con- 
 ceive, that the subordinate parts of each entire light-wave, 
 which is a universal or individual system, may be distinct 
 vibrations of exceeding minuteness, varying from each 
 other in dimensions and energy, according to their rela- 
 tive positions in the universal: in that part of the light- 
 wave which is most condensed, the subordinate vibra- 
 tions would be shortest and slowest; and in the most 
 rarefied part, the longest and most rapid. And between 
 these extremes, as in every regular co-ordination, whether 
 physical or logical, there will be a gradual passage from 
 one to another : this is on the principle of that antithesis, 
 in which extension and intension increase and decrease 
 in the exact inverse ratio of each other; the point at 
 which these diverging series cross being one of equili- 
 brium. 
 
 When by means of any peculiar construction, as that of 
 a prism, a light- wave, during its passage, is refracted, the 
 subordinate parts of the undulation are so projected on a 
 plane, as to render each distinctly visible ; thus, a species 
 of analysis is performed, separating the component parts of 
 the entire light-wave, which parts, having different degrees 
 of refrangitility, appear at corresponding positions in the 
 spectrum as a series of various colours. But when the 
 light- waves fall on .bodies which do not produce this pris- 
 matic or iridescent phenomenon, but only exhibit one 
 colour, either simple or compound, this must be referred 
 to the peculiar molecular constitution of the body, which 
 
 1 
 
MANIFESTED AS SOUND AND LIGHT. 119 
 
 reflects one of the subordinate vibrations of the light-wave, 
 whilst the others are involved or diffused through its 
 interstices. That the specific colour of a body is attribu- 
 table to its molecular condition, can scarcely be doubted; 
 for we have it in our power, by heat and otherwise, to 
 alter the molecular arrangement ; and when this is done, 
 the colour is, more or less, affected thereby: thus, many 
 oxides and sulphurets of brilliant colours, when heated 
 become gradually darker and clouded, till at last they are 
 perfectly black, but return to their original colour on 
 cooling. 
 
 " In addition to the ordinary prismatic colours described 
 by Newton, Sir John Herschel * has discovered a set of 
 very dark red rays, beyond the red extremity of the spec- 
 trum, which can be only seen when the eye is defended 
 from the glare of the other colours by a dark blue cobalt 
 glass : and he also found that beyond the extreme violet 
 there are visible rays of a lavender grey colour, which 
 may be seen by throwing the spectrum on paper moistened 
 by a solution of carbonate of soda. " 
 
 The illuminating power of the different rays of the 
 spectrum varies with the colour : the most intense light is 
 in the mean yellow ray. Doubtless in light- waves as in 
 sound-waves, the range of vibrations which affect the 
 organs of sense, does not mark the limit of these motions : 
 some may be so slow and others so fast as not to pro- 
 duce distinct impressions on the optic nerve; and the 
 above-mentioned experiments show that such vibrations 
 extend beyond the limits of the spectrum ordinarily visible; 
 
 * Mrs. Somerville's Connexion of Physical Sciences, p, 181. 
 I 4 
 
120 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 and the means employed to render them visible produce 
 new reactions, which modify the velocities of the abnormal 
 vibrations ; by which contrivances many other perturba- 
 tions might be obtained within the limits of the spectrum. 
 Sir David Brewster is of opinion that the spectrum actu- 
 ally consists of only three primary colours, red, yellow, 
 and blue ; and that the other tints are produced by the 
 variable overlapping of these primary colours. 
 
 These and many other curious circumstances concerning 
 colours might be enumerated ; but sufficient have been 
 noticed to make it evident that colours alone do not com- 
 prise all our knowledge concerning light-waves : we must, 
 therefore, now turn our attention to some other circum- 
 stances, in relation to luminous undulations. 
 
 Light is essentially the same, whatever may be its origin ; 
 but in our inquiries into its nature we deal with that 
 light which proceeds directly from the sun, and which we 
 speak of familiarly as the sun's rays. The brilliant light 
 of the sun is not only capable of exciting the sensations of 
 all the colours of the rainbow, but when it impinges on 
 us, it also produces the feeling of heat. The co-existence 
 of light and heat in the sun's rays is a well-known fact. 
 But it was Sir William Herschel who first pointed out 
 their relative distribution in the solar spectrum : he found 
 heat to predominate in the dark space a little beyond the 
 red extremity, and from thence to decrease gradually 
 towards the violet; beyond which its presence could not be 
 detected. From which it was concluded, that the calorific 
 rays vary in refrangibility, and that those beyond the 
 extreme red end of the spectrum are less refrangible than 
 any rays of coloured light. And since his time, it has 
 
MANIFESTED AS SOUND AND LIGHT. 121 
 
 been ascertained that the calorific spectrum exceeds tho 
 luminous, in the ratio of 42 to 25*; and that its maxi- 
 mum point is only slightly thrown out of the straight 
 line which the solar pencil would take had it not been 
 interrupted by the prism. 
 
 Wonderful as these phenomena of colour and heat are, 
 yet there are others of another kind also related to the 
 sun's rays, with which we must become acquainted before 
 the constitution of the light-wave can be determined. It 
 was long known that vegetation is retarded and feeble 
 when deprived of the direct influence of the sun's rays, 
 as when overshadowed by dense foliage, or in deep 
 caverns, where only a diffused light can penetrate ; and 
 this was attributed to the absence of heat : but now we 
 know that the sun's rays impart something more than 
 heat, and that this may be intercepted whilst the heat-rays 
 are allowed to pass, and yet the plants will not thrive. 
 This principle of activity has been distinguished by the 
 name of actinism ; and it has been found that it not only 
 exerts an influence over vegetation, but also over chemical 
 combination, which is, indeed, in all probability, the im- 
 mediate cause of its influence on the functions of plants. 
 
 The action of the sun's rays in facilitating many combi- 
 nations had been often noticed and recorded; but these 
 facts were only regarded as curious and inexplicable 
 occurrences. Sir Humphry Davy and Wedgewood at- 
 tempted to apply the action of light on the salts of silver, 
 in copying various objects, but their success was not 
 sufficiently promising to induce them to persevere in their 
 
 * Mrs. Somerville's Connexion of Physical Sciences, p. 238. 
 
122 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 experiments. This subject has been taken up of late 
 years by Niepce, Daguerre, and Talbot, and carried to 
 great perfection by various artists, as a species of light- 
 drawing, called photography ; an art which has been 
 developed with almost unparalleled rapidity. 
 
 The precise nature of actinism is as yet an unsolved 
 problem ; but, whatever this force may be, it clearly does 
 not belong to the same category as heat, for it not only 
 makes its appearance at the opposite ends of the solar 
 spectrum, but also possesses very distinct and antagonistic 
 characters : it is, therefore, reasonable to infer that it is a 
 phase or mode of attraction, which is strongly corroborated 
 by its property of promoting chemical combinations. 
 
 Colour and heat enter into the constitution of the solar 
 spectrum, which has been long known, but it is only of 
 late years that it has been discovered that the new ray- 
 force, actinism, also plays a conspicuous part therein. 
 Actinic force occupies in the spectrum a position directly 
 the reverse of that of caloric ; it is at a maximum in the 
 colourless space beyond the violet rays, and gradually 
 diminishes as it approaches the red extremity of the 
 spectrum, where its presence is too feeble to be detected, 
 So that the positions of the actinic and calorific forces are 
 as opposite as are their respective attributes ; for heat 
 repels, or causes the molecules of bodies to recede from 
 each other ; whilst actinism tends to their approximation, 
 as indicated by its facilitating chemical actions. 
 
 Thus we have seen that the solar spectrum consists of 
 a series of colours like those of the rainbow, situated 
 between the two extreme colours of red and violet : but 
 this is not all. Superadded to these colours are the an- 
 
MANIFESTED AS SOUND AND LIGHT. 123 
 
 tagonistic forces, heat and actinism, which are both present 
 in each of the coloured spaces, but in different proportions. 
 The calorific rays* extend beyond the red extremity, and 
 the actinic rays overlap the violet extremity ; and if the 
 linear dimensions of these three parts of the spectrum be 
 taken, the colorific, calorific, and photographic rays will 
 be found to be in the proportion of 25, 42, and 55 ; so 
 that the entire spectrum is more than twice as long as the 
 visible part. These proportions, however, are somewhat 
 modified by the material of which the prism is made. 
 
 Having thus briefly stated the general features of the 
 case, let us now endeavour to apply our notion of the 
 dualism of powers to these facts, and to ascertain whether 
 the etherial vibrations, or light-waves, can be reduced to 
 our logical correlation, which is a composition of co- 
 existent and antithetic terms. Of the three sets of phe- 
 nomena in the spectrum, we conceive that the coloured 
 rays are only modifications of the universal light-wave, 
 parts which have no other differentiation than variations 
 in the length and velocities of their oscillations, which 
 depend on their constituent forces being combined in dif- 
 ferent proportions. All these subordinate kinds of ethe- 
 rial undulations, manifesting themselves as different 
 colours, are the conditioned existences of dualistic powers, 
 which form the subject matter of optics : just as molecules 
 of matter, and their different states, depending on their 
 dualistic powers, cohesion and caloric, are the objects 
 concerning which the science of molecules, or micronomy, 
 treats. Strictly speaking, optics only treats of visible 
 
 * Mrs. Somerville's Connexion of Physical Sciences, p. 239. 
 
124 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 undulations : but with a distinct proviso, it may be ex- 
 tended so as to include in its subject all etherial undula- 
 tions, whether visible or not. 
 
 The next point to be determined, having settled the natural 
 history or descriptive branch of optics, is to ascertain the 
 nature of the correlative forces which produce these phe- 
 nomena : and having ascertained the constitution of this 
 peculiar composition of forces, or dualism, it then re- 
 mains to investigate the varying relations of these forces 
 in the different modifications of these etherial undulations. 
 These forces we conceive to be, as may have been antici- 
 pated, radiant heat and actinism, the already acknowledged 
 causes of two sets of phenomena displayed in the solar 
 spectrum. The relative positions of these forces, actinism 
 and radiant heat, (or thermicity, as it may be called,) in the 
 spectrum, constitute a parallelogram of forces which may 
 be illustrated by a very oblong diagram, bisected by its 
 diagonal: each triangular portion, thus formed, will repre- 
 sent either force ; and also shows their relative proportions 
 in any particular part of the spectrum. It is evident, on 
 considering such an arrangement, that one force increases 
 as the other diminishes, and vice versa: and on cutting 
 off a given portion, say a quarter part, from both extremi- 
 ties, it will be found that one part consists almost, but 
 not entirely, of thermicity ; and the other, of actinism. 
 And if the intermediate moiety be divided into bands by 
 lines drawn parallel with the ends of the diagram, it will 
 be apparent that there is a central part in which the forces 
 are equal, corresponding with the most luminous, or yellow 
 part, of the spectrum ; whilst in the bands on either side 
 of this central part, one or other of the correlative forces 
 
MANIFESTED AS SOUND AND LIGHT. 125 
 
 predominates. In the red bands it is heat, and in the violet 
 actinism ; in the extreme bands the corresponding force 
 prevails almost to the exclusion of its correlative: but it is, 
 according to our notion, a physical impossibility that these 
 forces can be absolutely separated, so as to exist as simple 
 natural forces. 
 
 Now from this statement it follows, that in whatever 
 relative proportion these forces be conjoined, the result is 
 a dualism, having characters which will vary according to 
 its composition. The vibrations at the extreme parts of 
 the spectrum derive their properties from the excess of 
 their characteristic force ; and the quality of their motions 
 is such as to be incapable of producing any sensible im- 
 pression on the optic nerve: though at the same time 
 either plus force is readily manifested by its peculiar 
 attribute ; the one by its effect on the thermometer, the 
 other on chemical tests. On the other hand, the central 
 vibrations of the spectrum are visible, as coloured bands, 
 and are very differently constituted from those at the 
 extremities ; their component forces being either equal or 
 nearly approximating thereto, a condition which seems 
 to be requisite for the production of optical phenomena. 
 
 In the case of sound, we know that it is propagated 
 from all bodies in a state of sonorous vibration ; and that 
 such a state may be originated by any physical impulse. 
 And so, in like manner, light is communicated by all lumin- 
 ous bodies ; but it can only be primarily excited by the 
 impulse of an intense heat. At a moderate temperature, 
 bodies are not visible in the dark; but when gradually 
 heated until they become strongly ignited, they are first 
 of all faintly luminous, which goes on increasing till they 
 
126 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 at last give out a brilliant light. Heat then is the cause, 
 or primum mobile, of light : it is this repulsive force, as 
 tbermicity or radiant heat, which imparts the initial im- 
 pulse to the etherial fluid ; and it is the reaction of acti- 
 nism on the ether, when liberated by the transmission of 
 the aggressive force, which completes the etherial undu- 
 lation, which may or may not be manifested as light, 
 according to the character of the undulation. The greater 
 the intensity of the exciting cause the more vivid the 
 light, and the more energetic is the thermicity associated 
 with such light. Even in the case of feeble phos- 
 phorescence, (such as that of decaying wood, fish, and the 
 like,) it is probable that the luminous appearance depends 
 on the heat evolved by continuous chemical action; the 
 heat concerned therein is at a minimum, as in the case of 
 violet light, which, modified by particular conditions, gives 
 those opalescent and spectral appearances, which have of 
 late attracted so much attention. 
 
 The name actinism has the merit of not expressing any 
 particular hypothesis, but simply the fact that it is a ray- 
 force, or one of the forces of the sunbeam ; and on this 
 account we have retained it: but concerning actinism 
 itself, it unfortunately is generally supposed to be a 
 chemical force, which it certainly is not, according to our 
 understanding of such a force; and therefore we must 
 guard against such a conception. Actinism is to us 
 merely a mode of physical attraction, the inseparable 
 antagonist of radiant heat in etherial undulations or light- 
 waves : it is precisely analogous to the force which causes 
 the condensation of gases in porous bodies, and which 
 also is accompanied by chemical actions ; but this cohesive 
 
MANIFESTED AS SOUND AND LIGHT. 127 
 
 force, or attraction of cohesion, is not affinity or chemical 
 force; but like actinism it is only a phase or mode of 
 physical force producing an approximation of molecules, 
 which is favourable to chemical action. 
 
 This view of the subject, the antagonism of peculiar 
 phases of physical forces in the sunbeam,- enables us to 
 explain some anomalies, and also many phenomena which 
 have been observed in chemical and electrical actions, 
 when modified by the influence of the sun's rays. 
 
 At an early period in the history of Photography, it 
 was expected that those countries which enjoy cloudless 
 skies and bright sunshine would afford pictures of superior 
 excellence, and the most skilful artists were sent out for 
 this purpose ; but they met with the most signal failures ; 
 the lines of the pictures, instead of being sharp and well 
 defined, were very indistinct. Now it is not probable that 
 there is any variation in the relative proportions of the 
 forces in light- waves, however these may vary in intensity ; 
 but a bright sunshine, instantaneously and simultaneously 
 with its actinic or photographic action, imparts a con- 
 siderable warmth, which, by a rapid accumulation on the 
 plate, produces a repulsive state, which is unfavourable to 
 chemical action ; and though not sufficient to entirely 
 suspend the latter, yet it renders it very irregular. 
 
 We see something similar to this in the effects of the 
 sun's rays on vegetation at different seasons. In spring 
 the predominance of vapours in the air and the coldness 
 of the soil, reduce the intensity of the rays, producing 
 that degree of tension that favours actinic action, and 
 which seems to be especially conducive to the succulent 
 
128 MOLECULAR AND ETHERIAL UNDULATIONS 
 
 functions in the early growth of plants ; but during the 
 arid parching heats of autumn, when the more solid parts 
 of plants are ripening, the repulsive force of heat is 
 favourable in another direction; for, by expanding the 
 organic structures it promotes the movements of molecules 
 which are requisite both for physical and chemical changes. 
 That the defect in photographical operations is attributable 
 to the disturbing influence of an opposite or repulsive 
 force, is rendered probable by the fact that by increasing 
 the delicacy of the chemical preparations, the difficulty 
 is obviated ; the greater susceptibility to change enabling 
 the picture to be produced before the heating has become 
 sufficient to be detrimental ; and perhaps the same result 
 might be obtained by directly intercepting, or counteract- 
 ing the antagonistic energy, by using such coloured glasses 
 as would reduce the heating power of the sun's rays, 
 whilst a free passage is afforded to actinism.* 
 
 In conclusion, then, to sum up the contents of this 
 chapter, the subject-matter of the sciences of acoustics and 
 of optics is material undulation : that of the former being 
 molecular, of the latter, etherial. Acoustics, then, is the 
 science of molecular undulations ; optics, that of etherial 
 undulations. And the correlative forces which constitute 
 these material motions, and which by their actions and 
 reactions produce their respective phenomena, are in the 
 case of acoustics, impulsion or epipallism, and elasticity 
 peculiar phases of attraction and repulsion ; and in the 
 
 * Mr. Robert Hunt bas written fully on the subject of Actinism, 
 and although we have not made special quotations, we have been 
 largely indebted to him for our information thereon. 
 
MANIFESTED AS SOUND AND LIGHT. 129 
 
 case of optics, actinism, and radiant heat or thermacy. 
 As in the following correlations, 
 
 Epipallism 4- Elasticity = Molecular Vibrations or Sound. 
 Actinism + Thermacy = Etherial Vibrations or Light. 
 
 This may not be a correct view of the subject, but it 
 has at least a consistency, a homogeneity of doctrine which 
 is greatly in its favour. 
 
 K 
 
130 
 
 CHAP. V. 
 
 ELECTRICITY AND MAGNETISM, PHASES OF PHYSICAL 
 POWERS, FUNCTIONING IN THE POLAR MOVEMENTS 
 OF MATERIAL MOLECULES. 
 
 Electricity and Magnetism, cosmical or universal Forces. Elec- 
 trology the least advanced Branch of Physics. Electricity and 
 Magnetism are not the Noun-Substantives of distinct Sciences. 
 The various Modes of producing Electricity Explanation of its 
 Origin. Electricity a Mode of Physical Repulsion. Bodies not 
 always in an electrical State. Positive and negative Electricities, 
 are co-existent and co-equal. Electrical Induction, the Action of 
 contiguous Particles. The Relations of positive and negative 
 Poles to the Current. Poles only manifested when Current passes 
 through different Media. Oersted on the Relation of electrical 
 and magnetic Currents. Heat evolved during Magnetisation. A 
 Current of Magnetism lengthens the metallic Medium: that of 
 Electricity shortens it Explanation of these Phenomena. Dia- 
 magnetism discovered by Professor Faraday: supposed to be a 
 peculiar Force. Professor Tyndal's Experiments thereon. Mag- 
 necrystallic Force: a Crystal under its Influence virtually a Magnetic 
 Needle. Galvanism; Electro-magnetism; and other Forms of Polar 
 Forces. Conclusion. 
 
 THE last phases or modes of the physical powers, attrac- 
 tion and repulsion, which remain to be examined, are 
 electricity and magnetism. These forces are cosmical, or 
 universal, for all descriptions of material bodies are subject 
 to their influence : as regards electricity, this circumstance 
 has been long known ; but it is only recently, through 
 
ELECTRICITY AND MAGNETISM. 131 
 
 the researches of Faraday, that we have learnt that magnet- 
 ism is not restricted to iron and a few other metals, but 
 is capable of entering into relation with all bodies. This 
 character of universality is an important fact ; one which 
 may ultimately enable us to arrive at a clearer apprehen- 
 sion of these forces than we have at present. 
 
 The phenomena manifested by the operation of elec- 
 tricity and of magnetism on various bodies are polar ; that 
 is, they assume different aspects in opposite directions, as 
 in the case of the north and south poles of the magnet, 
 and of the positive and negative electricities. The electric 
 spark, and the direction in which the magnetic needle 
 points, and many similar and curious facts, are very im- 
 pressive ; but in regarding them, the attention has been 
 more fixed on the forces as causes, than on the phenomena 
 themselves ; a method of proceeding which has not usually 
 been followed in the treatment of the inductive sciences. 
 This we consider to be faulty ; but we need not dwell on 
 this topic, as it has already been discussed, when we gave 
 our reasons why thermotics ought not to be acknowledged 
 as a science ; and for the same reason we do not think it 
 correct to speak of the sciences of electricity and magnetism. 
 Forces by their actions and reactions produce phenomena, 
 as causes do effects ; and it is the latter only which are 
 dualisms or composition of forces, which can become the 
 objects of systematic knowledge : the idea of a system is 
 incompatible with that of an individual force, which can- 
 not function without being in relation to some other force ; 
 and it is such relations only which give the subject-matter 
 of a science. 
 
 We conceive therefore that whilst, on the one hand, it 
 
 K.2 
 
132 ELECTKICITY AND MAGNETISM. 
 
 is requisite that these physical forces, electricity and mag- 
 netism, should be investigated, in all their characteristics, 
 their modes and velocity of transmission, and their relations 
 to other forces ; yet when all this has been accomplished, 
 it does not put us in possession of two sciences ; for as 
 Comte has justly remarked, "facts do not constitute 
 science, though they are its foundation and material. 
 Science consists in the systematising of facts under 
 established general laws ; and regarded in this way, elec- 
 trology is the least advanced of all the branches of 
 physics. Those who have occupied themselves with ima- 
 ginary fluids, as the causes of electrical and magnetical 
 phenomena, have transferred the general laws of rational 
 mechanics to the mutual action of their molecules ; thus 
 making the body under notice a mere substratum, necessary 
 for the manifestation of the phenomenon, but unconcerned 
 in its production, with which office the fluid is charged. 
 It is clear that mathematical labours so baseless can serve 
 no other purpose than that of analytical exercise, without 
 adding a particle to our knowledge : they have borne no 
 share in the great discoveries of the present day ; though 
 the discoveries, once made, have been afterwards attached 
 to the hypothesis." * 
 
 If we have not misunderstood this passage, Comte 
 points out the importance of studying electricity on a 
 wider platform ; that its influence, whether an imponderable 
 fluid or a force, is not alone to be regarded in the con- 
 sideration of the phenomenon ; that there is some reaction 
 between it and the bodies with which it is associated, 
 
 * Positive Philosophy, vol. i. p. 278. 
 
A PHASE OF THE PHYSICAL DUALISM. 133 
 
 which must not be overlooked. At least, this is the con- 
 clusion at which we have arrived, whether it coincides with 
 that of Comte or not : the transient movements of the 
 molecules of bodies during the transmission of electricity, 
 are strictly speaking the subject-matter of a physical 
 science, but not the forces which cause the phenomena. 
 If it be so, to what condition of material bodies are we 
 then to direct our attention in this research ? 
 
 The subject of physics, which treats of the phenomena 
 arising from the action and reaction of physical forces, is 
 in all cases motion : and as the modes of these forces vary, 
 so must the resulting motions assume different aspects. 
 And in thus following out the various phases of physical 
 powers, we have already considered the rotations and 
 revolutions of celestial bodies, the changes of states in 
 matter, atomic and molecular undulations ; and now, lastly, 
 there remain those polar motions or polarity, the actions 
 and reactions produced by electricity and magnetism. 
 
 By polar motions, in. this sense, we do not mean the 
 distinct and independent movements of magnetised or of 
 electrified bodies, the mere responses of the positive and 
 negative poles of such bodies ; but we understand thereby 
 a general and combined arrangement, in which both forces 
 are engaged. Polar forces are the correlatives of a dualism: 
 which must, therefore, be inseparably co-existent and 
 directly opposite, in the character of their attributes. Now 
 all these characteristics are fulfilled in electricity and 
 magnetism ; so that if our reasoning be correct, we are 
 irresistibly compelled to accept them as the dualism of 
 forces, which is required to function in polar motions. 
 
 It will be no easy task to make this view of the subject 
 
 K 3 
 
134 ELECTRICITY AND MAGNETISM. 
 
 meet all its requirements ; such a co-ordination, however, 
 is necessary to complete the system of physical forces; and 
 though, in some instances, it may seem to run counter 
 to present notions, yet it will, we think, be found to 
 renconcile many apparent inconsistencies. 
 
 Thus, in a few words, we have endeavoured to set forth 
 what we conceive to be the relation subsisting between 
 electricity and magnetism : and which receives no little 
 support from a modern discovery ; viz., that whenever a 
 current of either of these forces is established, a current 
 of the other is simultaneously produced, which flows in a 
 direction at right angles to the original current : a fact 
 which impressively calls to mind the relative positions of 
 gravitation and centrifugal force; but which is nowise 
 surprising, when we know that these central forces are 
 only particular modes of the universal physical forces. 
 
 We now proceed to enter more into detail concerning 
 electricity and magnetism ; which of course cannot be an 
 exhaustive account, but only sufficiently circumstantial to 
 serve the purpose of our inquiry. And, in the first place, 
 we will direct attention to electricity, which, as already 
 remarked, is an all-pervading force in nature. Its uni- 
 versality seems to be such, that it may be elicited from all 
 kinds of matter ; and by any operations which may pro- 
 duce a molecular change in the condition of bodies. Thus, 
 friction of any kind, between dissimilar substances, or 
 even between the same kind of substance in different con- 
 ditions, or even simple contact of some bodies, will suffice 
 to evolve electricity ; and the same happens when bodies 
 change their state, when heated, or when chemically acted 
 on ^ in short, any disturbance of molecular arrangement. 
 
A PHASE OF THE PHYSICAL DUALISM. 135 
 
 Now, in all these cases, there must be a disturbing force, 
 be it great or be it small, which occasions these molecular 
 motions. What becomes of this motion ; and of the force 
 by which it was produced ? The forces employed in these 
 operations do not arrest attention, we are so much occupied 
 with the curious phenomenon which follows ; but let not 
 this applied force be lightly passed over : and, in order to 
 simplify our remarks, let heat be selected as the agent. 
 
 Formerly, heat, a modal variety of repulsion, could not 
 have been clearly understood in such an operation : but, 
 since the researches of Joule have taught us that heat may be 
 measured by the work performed, through the medium of 
 a machine, our notion concerning it has become much 
 more definite. When, therefore, a given force, as heat, 
 acts on the molecules of a body and puts them in motion, 
 the molecules perform the part of a medium.) transmitting 
 force by continuous repetition of limited motions, and 
 may consequently be regarded as a machine in motion, 
 which transmits power as long as the application of the 
 primum mobile continues, but falls back to a state of rest 
 as soon as the oscillating action and reaction ceases. The 
 heat during its transition may become so diffused, as to 
 produce no sensible effects ; but if of sufficient intensity, 
 it will, on its escape from this medium into another, mani- 
 fest itself as a distinct force, as appreciable as when it 
 entered into the molecular body. Must this force, then, 
 appear again as heat ? As some kind of repulsive force 
 it must certainly appear, for the principle of the conser- 
 vation of forces requires thus much ; but it does not fol- 
 low that the phase of repulsion will be that of heat ; for 
 the character of the force will depend on the manner of 
 
 K 4 
 
136 ELECTRICITY AND MAGNETISM. 
 
 its transmission ; that is, it will be modified according to 
 the nature of the molecular motions. Thus heat, as well 
 as the impact of another body in motion, may cause the 
 molecules of a body to vibrate, and this motion will issue 
 from the body as sonorous undulations; and so also when the 
 molecules are affected by polar movements in a continued 
 series of alternate mutations, then electrical phenomena 
 are evoked, either as positive or negative effects, when its 
 passage is through different media, or as currents when 
 the polar actions are uninterruptedly continuous. 
 
 On this view of the subject, electricity is that phase of 
 repulsion which this universal force assumes when mole- 
 cules are actuated by polar motions ; and it passes on from 
 molecule to molecule by the alternate movement of their 
 poles, just as radiant heat and mechanical impulses are 
 transmitted by undulations ; and being a repulsive force, 
 the action of which has an outward tendency, its presence 
 is commonly more conspicuous on the surface of bodies. 
 The different conditions of molecular movements are the 
 phenomena which indicate an alteration in the modus 
 operandi of their efficient causes : and for this reason, we 
 properly discriminate between the different phases of the 
 same forces ; and for this reason we one while call the 
 repulsive force heat, and at another electricity, though at 
 the same time admitting that they are ultimately one and 
 the same power. 
 
 It has already been observed that electricity is a uni- 
 versal force, that is, a force capable of entering into 
 relation with all natural bodies; but it does not follow 
 from this that all bodies are constantly in an electrical 
 state, as is generally supposed, or that all that is requisite 
 
A PHASE OF THE PHYSICAL DUALISM. 137 
 
 to excite electricity is to alter the statical state of bodies 
 in this respect. It is, indeed, probable that currents of 
 electricity, perpetually excited by the action of the sun's 
 rays, may circulate around the earth's equator, as continu- 
 ously as magnetism flows in an unceasing stream, in the 
 direction of the north and south poles; and if so, of course 
 all bodies must be more or less exposed to this electrical 
 action. But we do not think it expedient to regard bodies 
 as containing combined electricity either positive or nega- 
 tive, and classifying them according to this supposed 
 constitution/ All bodies may be electrically excited, for 
 the molecules of all are capable of polar motions ; but they 
 are not always in this condition, owing to the interposition 
 of various antagonisms, so that bodies cannot be supposed 
 to be always in an electrical state. 
 
 All molecules must be regarded as having two distinct 
 electrical poles, the positive and the negative, and so 
 accordingly we commonly speak of a positive and of a 
 negative electricity. Franklin considered these electricities 
 as only the opposite states of one and the same force ; 
 whilst Dufay and others have maintained that they are two 
 distinct fluids. Faraday *, in his Researches in Electricity, 
 says, " that he has sought for evidence capable of sustain- 
 ing the theory of two electricities rather than that of one, 
 but has not been able to perceive a single fact which could 
 be brought forward for such a purpose ; or, admitting the 
 hypothesis of two electricities, he could not detect the 
 slightest grounds for believing that one electricity in a 
 current can be more powerful than the other, or that it 
 
 * Philosophical Transactions, Series v., 1833. 
 
138 ELECTRICITY AND MAGNETISM. 
 
 can be present without the other ; or that one can be varied, 
 or in the slightest degree affected, without a corresponding 
 variation in the other. And judging from facts only, there 
 is not as yet the slightest reason for considering the influ- 
 ence, which is present in what we call the electric current, 
 as a compound or complicated influence. It has never 
 been resolved into simpler or elementary influences, and 
 may perhaps be best conceived of as an axis of power 
 having contrary forces, exactly equal in amount, in contrary 
 directions" 
 
 These conclusions of Faraday are invaluable. At first 
 sight, the latter clause seems to be a contradiction of the 
 former, for if there are no facts indicative of two electri- 
 cities, how comes it to pass that the electrical current is 
 composed of contrary and equal forces? This is very 
 difficult to conceive, and the idea of such an efficiency, 
 exerted in contrary directions, approximates very nearly 
 to that of the positive and negative electricities, which are 
 supposed to be co-existent but opposite forces. Doubtless 
 Faraday himself has a clear apprehension of such an axis 
 of power, which others very competent to judge have 
 indeed accepted as an important hypothesis ; we confess, 
 however, that we are unable to reconcile the apparent 
 contradiction, but we must strive to grapple with the 
 difficulty, and consider how far it may be rendered consis- 
 tent with our notion concerning natural forces. 
 
 Much of the perplexity arises, we think, from the mis- 
 apprehension of the nature of electrical and magnetic 
 polarities. In both cases, one kind of pole attracts the 
 other ; and poles of the same kind uniformly repel each 
 other. When bodies are under the influence of either 
 
A PHASE OP THE PHYSICAL DUALISM. 139 
 
 electricity or of magnetism, they give indications that one 
 extremity is the positive, and the other the negative pole ; 
 and divide these bodies as often as you may, still each end 
 has an opposite pole; and this there is every reason to 
 believe would hold good, even could we arrive at the 
 ultimate molecules of the body. After having broken up 
 a body in this manner, if we put the parts together again 
 so as to reconstruct the body (which to a certain extent is 
 practicable in the case of the magnet), this might be done 
 so as to give the body the form of a long chain, each link 
 having two poles, and being united to the adjacent links 
 by opposite poles, and in this manner the entire chain would 
 become virtually one body, having a positive pole at one 
 extremity and a negative at the other. In the next place, 
 make a closed circuit by bringing the two ends of the 
 chain together, and there is no longer a distinction of poles, 
 the force moving in a continuous current ; the previous 
 character is not destroyed by this arrangement, for break 
 the continuity of the chain at any part, and the opposite 
 poles immediately reappear. From these facts, we conclude 
 that both electricity and magnetism are forces which move 
 in concentric currents around certain axes ; that the move- 
 ment in currents is the normal function of these forces, 
 from which they never depart ; and that, when they assume 
 a different aspect, as when they respectively exhibit the 
 phenomenon of poles, the departure is more apparent than 
 real. The current still flows on in a continuous re-enter- 
 ing stream, but its course is no longer through one but 
 different media ; and in its transition from one medium to 
 another, a great change takes place, a perturbation which 
 is manifested as the opposite poles of an axis. All bodies, 
 
140 ELECTRICITY AND MAGNETISM. 
 
 whether electrified or magnetised, are thus affected, exhibit- 
 ing opposite poles, beyond which the current-force is 
 continued by induction ; which is no other than the mode 
 in which the current progresses in a different medium ; and 
 the direction of such inductions tends to the union of 
 opposite poles, as shown in the magnetic field, when the 
 lines of force are rendered apparent by the arrangement 
 of fine particles of iron. In these currents, the force is 
 exerted in one direction; and when any part of such 
 current is broken, the end of the body which points in 
 this direction is called the positive pole, and the opposite, 
 or re-entering end, the negative pole. If a more powerful 
 pole be forcibly held in any direction near a weaker pole 
 of the same kind, both poles will be in a state of antagon- 
 ism ; and if the weaker pole can move, it must assume the 
 direction of the stronger, which being opposite is equivalent 
 to repulsion, or the reversing of its original direction. 
 
 According to this interpretation, the movement at the 
 negative pole must be co-existent, opposite, and, as Faraday 
 states, co-equal with that of the positive pole ; whatever 
 takes place at one pole must have a simultaneous coincidence 
 in all things, except a contrariety of position and direction. 
 We cannot, therefore, regard the poles, either of electri- 
 city or of magnetism, as indicative of two forces, but only 
 as certain conditions of one and the same force. This is 
 a conception which is not at first glance easily understood, 
 but as we become familiar with it much of the perplexity 
 disappears. The current of such a force is its onward 
 propagation, by the alternate movement of the molecules 
 on their axes, forward and backward ; and there is an- 
 other correlative force present which maintains the mole- 
 
A PHASE OF THE PHYSICAL DUALISM. 141 
 
 culcs in their position, forming the axes, as it were, on 
 which the molecules turn ; and when the aggressive or 
 moving force is transmitted onward, the other, or tangen- 
 tial force, reacts, and is the means of restoring the original 
 arrangement. Now this polar excitement and transmis- 
 sion may occur with either force, as one or other of 
 the correlative forces predominates. Thus if the action 
 of a repulsive force produce an electrical excitement, a 
 current of electricity will be evolved ; but simultaneously 
 therewith another current must be elicited tangentially 
 thereto, and as there is only one other polar force known, 
 viz. magnetism, we cannot escape the conviction that 
 electricity and magnetism are the correlative forces con- 
 cerned in the polar motions of molecules. Such a notion 
 would have appeared very absurd in the infancy of our 
 knowledge concerning these forces ; but since the impor- 
 tant discovery of Oersted concerning the intimate relation 
 of eLctricity and magnetism, and the subsequent exten- 
 sion of this subject by the researches of others, we are 
 prepared to accept such an association as has been sug- 
 gested. 
 
 It is now well known that a closed current of either 
 force is simultaneously accompanied by a current of the 
 opposite force tangentially thereto, and that whichever 
 force is in the ascendant, it revolves around the other force, 
 which forms a fixed axis for the rotation; just as in a 
 celestial body the discharge of centrifugal force causes an 
 equatorial movement around the poles of the body, which 
 are maintained as a stable axis of motion by the force of 
 gravitation. Now what we are desirous of establishing is, 
 that electricity and magnetism are not only thus associated 
 
142 ELECTRICITY AND MAGNETISM. 
 
 in co-existent currents, but that whilst the energising 
 force is progressive, the reacting force, in a state of 
 tension, is equally concerned in the polar phenomena. At 
 all events, the poles of either force cannot be two things, 
 but only aspects of one and the same ; for we cannot con- 
 ceive of forces existing always in the same relations. 
 
 Should this suggestion be deemed worthy of considera- 
 tion, it will be found to point to the same dualistic 
 constitution which we have found to obtain in all the 
 other conditions of material bodies ; and if we admit that 
 the dualism of polar forces consists of electricity and 
 magnetism, we accept them as modes or phases of the 
 universal physical forces, attraction and repulsion. Elec- 
 tricity thus offers itself in polar motions, as a phase of 
 repulsion tending to expansive diffusions ; whilst magnet- 
 ism, a phase of attraction, is a more permanent and 
 coercive force ; and when we consider these antagonistic 
 relations, we find a ready explanation of many curious 
 circumstances connected with these forces. Thus during 
 magnetisation, heat is produced, indicating an approxima- 
 tion of molecules by an increased attraction : similiar to 
 that which takes place on the compression of a body ; 
 intimating, as we have said, that magnetism is a phase of 
 attraction, and consequently acts in the same direction. 
 On the other hand, when a magnet is heated, it loses its 
 virtue ; some say that this only occurs under certain 
 conditions, but Gauss has set this at rest by his excellent 
 researches ; the fact is now established, that magnetism is 
 always diminished by heat, and, at elevated temperatures, 
 is entirely subverted. We say subverted, and not destroyed ; 
 for heat being a repulsive, and magnetism an attractive 
 
A PHASE OF THE PHYSICAL DUALISM. 143 
 
 force, the former, when it predominates, renders the latter 
 latent or passive, either as magnetism, or as some other 
 mode of the same force, for forces are indestructible. 
 Joule, who discovered the evolution of heat during mag- 
 netic induction, observed that the entire volume of the 
 magnet is not altered ; for what it gains in length, it 
 loses in breadth; showing that the magnetic coercion 
 is curiously analogous to the rolling of a bar, or the draw- 
 ing of a wire. The molecules are arranged and contracted 
 by the coercive current in one direction, and extended in 
 the opposite ; and in like manner many of the results ob- 
 tained by Becquerel and Wertheim, by subjecting magnetic 
 bars to torsion and hammering, may be explained. These 
 illustrations might be greatly enlarged, but they suffice 
 to show the relation between magnetism and the mo- 
 lecular constitution of bodies. Electricity also is concerned 
 in corresponding phenomena ; but as these are necessarily 
 of an opposite character, they require an explanation the 
 reverse of the former. Thus, when a current of electricity 
 is passed through a wire, the tendency is to shorten it, 
 and to increase its thickness: its repulsive force counteracts 
 and subverts the constrained state of the molecules, oc- 
 casioned by the elongating compression of the wire-draw- 
 ing process ; and the molecules, being set at liberty, re- 
 arrange themselves in the normal condition of the metal. 
 
 When the molecules of bodies are under the influence 
 of polar motions, how comes it to pass that we have not 
 always both electrical and magnetic phenomena, if these 
 forces co-exist ? whereas we commonly find, that only one 
 of these forces is manifested at a time : if repulsive force 
 prevails, the resulting phenomena are electrical, but if the 
 
144 ELECTRICITY AND MAGNETISM. 
 
 opposite force is in the ascendant, the phenomena are mag- 
 netic. Now this is perfectly analogous to all the other 
 kinds of physical motions which have been already con- 
 sidered ; and in which the correlative forces of each dual- 
 ism, according to their respective relations, produce corre- 
 sponding effects. Thus, in the different states of matter, 
 solids, liquids, and gases, each condition respectively 
 depends on the relative proportions of the dualistic forces, 
 cohesion and caloric : and if we seek to know why these 
 conditions so greatly influence electrical and magnetic phe- 
 nomena, the answer is ready at hand, when we remember 
 that the forces concerned therein, as well as those relating 
 to the different states of matter, are fundamentally iden- 
 tical ; being all modes of the same physical powers, attrac- 
 tion and repulsion, differing only from each other in their 
 modus operandi on molecules. From such a stand-point, 
 we see that when magnetism coincides with the attraction 
 of cohesion, they mutually facilitate each other's action, 
 because they operate in the same direction ; as is beauti- 
 fully illustrated by the behaviour of crystals of different 
 systems when suspended in the magnetic field : but if 
 magnetism be resisted by the counteraction of repulsive 
 heat, then it sustains a corresponding reduction of energy. 
 And, mutatis mutandis, the same remarks apply to elec- 
 tricity, in its concurrence with different kinds of physical 
 forces : thus, in the electrolysis of chemical substances 
 several illustrations will readily suggest themselves. 
 
 By the researches of Faraway we have learnt that 
 ordinary electrical induction is in all cases " an action of 
 contiguous particles," a species of polarity, and not a 
 mutual influence of either particles or masses at sensible 
 
A PHASE OF THE PHYSICAL DUALISM. 145 
 
 distances. It is, indeed, as already stated, an extension 
 of polar motions into different media, through which the 
 forces tend to complete a circuit, by which the poles of 
 bodies become parts of, and involved in, a continuous 
 current. And it follows that when by induction, (as well 
 as in the case of conduction, in which this condition is 
 more grossly apparent,) the circuit is completed, an an- 
 tagonistic current must necessarily be called into exist- 
 ence, which assumes a tangential arrangement. Should 
 this reasoning be admitted, it offers a solution of those 
 diamagnetic phenomena, for the knowledge of which we 
 are indebted to Faraday. 
 
 Some have thought that bodies are magnetic or diamag- 
 netic only in virtue of possessing different degrees of 
 magnetism ; and this was Faraday's first view of the 
 subject : but he has seen reason to question it, and he 
 now regards the movements of diamagnetics in the field of 
 force as due to a peculiar influence different from that of 
 ordinary magnetism. Diamagnetism manifests itself when 
 non-magnetic bodies are placed between the opposite poles 
 of a magnet; it cannot be called into activity by any 
 other condition, as electricity and magnetism can, by 
 various modes of excitement. On this and other conside- 
 rations we are inclined to think that it is decidedly 
 different from magnetism, but we do not think that it is a 
 peculiar and unknown force : it acts as a polar force, 
 equatorially to the axial current of magnetism, which is 
 the characteristic of electricity; and on this account we 
 are disposed to regard the latter and diamagnetism as 
 identically the same force. 
 
 In the magnetic field, between the poles of a magnet, 
 
146 ELECTRICITY AND MAGNETISM. 
 
 the curved lines of force meet in closed currents in the 
 air by induction; and when this is once effected, a counter 
 current of electricity ought also to be evoked tangentially 
 thereto : and thus it comes to pass that diamagnetic bodies 
 suspended between the poles of the magnet, move slowly 
 at first, but quicker subsequently as the current becomes 
 established ; and lastly arrange themselves in an equatorial 
 position, which corresponds to that which they would 
 assume under the influence of electricity. If the bodies 
 placed in the magnetic field be capable of forming part of 
 the magnetic circle ; that is if, like iron, their molecules 
 are susceptible of being magnetically polarised, then they 
 will take up a contrary, or axial, position in the direction 
 of the magnetic current, of which they will form a part. 
 This explanation may prove to be insufficient, but at all 
 events it has the merit of rendering the multiplication of 
 forces unnecessary ; and this tendency to simplicity is no 
 bad criterion of scientific validity. 
 
 Professor Tyndal * has also diligently investigated this 
 subject, and has illustrated the relations of bodies to the 
 separate poles of the magnet by some interesting experi- 
 ments. He has shown that a diamagnetised body is 
 capable of assuming a condition peculiar to each pole, that 
 io, of a dual excitation ; and he therefore gives the pre- 
 ference to Faraday's original hypothesis, that diamagnetic 
 bodies, operated upon by magnetism, possess a polarity 
 " the same in kind but the reverse in direction of that 
 acquired by magnetic bodies." In passing we may remark, 
 that this definition is not very inapplicable to electricity. 
 
 * Philosophical Transactions, vol. cxlv. pp. 38, 40, 51. 
 
A PHASE OF THE PHYSICAL DUALISM. 147 
 
 As regards Professor Tyndal's experiments, if it be re- 
 membered that the curved lines of force, which proceed 
 from either pole of the magnet, are parts of continuous 
 currents, which broken at any point by the interposition 
 of a different medium must manifest opposite poles with 
 their respective characteristics, we may expect to find the 
 phenomena to vary accordingly : the poles of the inter- 
 posed body, now forming part of the magnetic current, 
 must agree or not with the poles" of the magnet, according 
 to their relative positions ; that is, each part of the chain 
 of polar motions, whether the molecules of the interposed 
 air or of any body involved therein, is, as it were, a separate 
 magnet, and consequently each and all are subject to the 
 laws of magnetism. 
 
 The same indefatigable experimenter has made known 
 a number of facts concerning the departure of both mag- 
 netic and diamagnetic bodies from their normal positions, 
 when placed between magnetic poles of a triangular form. 
 Had these departures only taken place in the case of dia- 
 magnetic bodies, the result would have been most per- 
 plexing: but as it is, we have only to explain the phenomena 
 of magnetic bodies in this peculiar position ; and then we 
 shall be able to understand those of the other kind, since 
 they must be of a directly opposite character. Why then 
 do magnetic bodies, above and below such pointed poles 
 of a magnet, change the axial to the equatorial direction ? 
 It can only be attributed to a peculiar arrangement of 
 the lines of force in the magnetic field, produced by the 
 brush -like form which the currents must assume on issuing 
 from, and re-entering at, the pointed poles of the magnet : 
 which arrangement admits of the direct lines of force 
 
 L 2 
 
148 ELECTRICITY AND MAGNETISM. 
 
 passing in an uninterrupted stream ; whilst the other lines, 
 both above and below, must be greatly perturbed by the 
 crossings of diverging rays. However this may be ac- 
 complished, the fact indicates that the current is uniformly 
 flowing in one and the same direction, and therefore on 
 the upper and the under lines must necessarily point in 
 opposite directions ; whilst the co-existent and opposite 
 electrical current, whatever the modification of the mag- 
 netic current, must undergo a corresponding change. A 
 more distinct and definite description of such a complex 
 arrangement may be given by geometers in a diagram : all 
 we can do is to point out the probability and the pos- 
 sibility of a system of intersecting currents, when viewed 
 in different positions, presenting appearances of a directly 
 contrary aspect. 
 
 It has been supposed that the diamagnetic force is the 
 same as that by which crystals are actuated when in the 
 magnetic field, and which affords phenomena varying in 
 character as the axes of the crystals are optically positive 
 or negative : whilst on the other hand Plucker ascribes 
 these phenomena to the action of a peculiar force, entirely 
 different from that of magnetism or of diamagnetism. 
 Faraday*, in his almost exhaustive researches in electricity, 
 has carefully investigated the subject of crystallic force : 
 and he obtained results different from those of Plucker, 
 concerning the relation of the optical axes to mngnetic 
 action. Pliicker's force is equatorial, whereas that of 
 Faraday is axial, which he has named the magne-crystallic 
 force. " This force," says Faraday, " is not only axial ; but 
 
 * Philosophical Transactions, Series xxii. 2469, 2472, 2479. 
 
A PHASE OF THE PHYSICAL DUALISM. 149 
 
 it is doubtless resident in the particles of the crystal : 
 it is such that the crystal can set with equal readiness and 
 permanence in two diametral positions ; and between these 
 there are two positions of equatorial equilibrium, which are 
 of course unstable in their nature. The magne-crystallic 
 force does not manifest itself by attraction or repulsion, but 
 gives position only. The law of action appears to be that the 
 line or axis of this force (being the resultant of the action 
 of all the molecules) tends to place itself parallel, or as a 
 tangent to the magnetic curve or line of magnetic force, 
 passing through the place where the crystal is situated." 
 In a later communication Faraday* observes that "the apti- 
 tude of a magne-crystal, when in the magnetic field, to 
 assume a maximum conductive state in a given direction, 
 makes it similar in action to a permanently magnetised 
 sphere ; and therefore however diamagnetic it may be, 
 and however slight its magne-crystallic condition, still it 
 will set in a definite direction." 
 
 On this topic we would venture to suggest that a piece 
 of iron is so molecularly constituted that it readily trans- 
 mits magnetic force in any direction ; so that when placed 
 in a magnetic field, if it be free to move, it will arrange 
 itself axially in the direction of its length : but a crystal 
 is different, it conducts best in the direction of its crys- 
 talline axes ; on these lines it assumes a definite position, 
 and is therefore in this respect virtually a magnetic 
 needle, and may be substituted for the ordinary steel 
 needle with advantage, in some circumstances, as pointed 
 out by Faraday. But, like iron, the crystal is not coercive, 
 
 * Philosophical Transactions, Series xxx. 3384, 3385. 
 L 3 
 
150 ELECTRICITY AND MAGNETISM. 
 
 and therefore does not retain the magnetic property when 
 removed from the closed current, as in the case of steel. 
 Surely this fact cannot intimate that magnetised crystals are. 
 actuated by any peculiar force, such as the name magne- 
 crystallic force would seem to imply ? We can only see in 
 this circumstance that cohesion, the attractive force which 
 unites the molecules, exists in greater intensity on certain 
 lines or axes of crystals, producing a structure favourable 
 to the passage of magnetism; or, in the more usual mode of 
 expressing it, crystals are better conductors of magnetism 
 in the direction of their axes. Now magnetism and cohesion 
 are analogous attractive forces ; and as similar forces coin- 
 ciding in tendency, they do not retard, but facilitate each 
 each other's actions ; so that it might be expected that 
 magnetism would follow the axes of crystals in preference 
 to all other directions. 
 
 It seems to us to be unnecessary to dwell on those various 
 forces of electricity and magnetism which are evolved 
 under different combinations. The most interesting, that 
 of galvanism, is a continuous current of electricity, evolved 
 by chemical actions: in all of which a change in the 
 position of the molecules of bodies must take place ; and 
 such changes give rise to a diffusion of repulsive force, 
 functioning in polar motions, which, by the peculiar 
 arrangement of the apparatus, is conveyed away by con- 
 ducting wires. There is, therefore, no difference in 
 principle in this mode of excitation from that of others 
 by which electricity is evoked into activity, as when the 
 molecules are disturbed by mechanical actions or by heat ; 
 in each case very different arrangements are required : 
 but whether electricity be excited by friction, heat, or 
 
A PHASE OF THE PHYSICAL DUALISM. 151 
 
 chemical action, it is in all cases one and the same kind of 
 force. 
 
 Whenever there is a closed current of either electricity 
 or magnetism, as already stated, the correlative force is 
 immediately called into existence, and may be manifested 
 in a direction tangentially thereto : in correspondence with 
 this fact various kinds of apparatus have been invented 
 to exhibit the resulting phenomena ; and we speak of the 
 forces thus concerned as electro -magnetism, and magneto- 
 electricity, according to the force employed for the excita- 
 tion of its correlative. The phenomena are very interesting 
 and instructive : but they do not afford any facts different 
 from those which we have been considering, and therefore 
 cannot furnish us with any additional information for the 
 illustration of our subject. 
 
 In conclusion, therefore, we will only observe that the 
 forces of electricity and magnetism cannot, on our view of 
 the subject, become the subject-matter of special sciences. 
 To be in accordance with the other physical sciences, and 
 more particularly with that of astronomy which is the 
 farthest advanced toward perfection, these forces should 
 be related to some form of physical substance, some kind 
 of material body, which must exhibit such peculiar mo- 
 tions as do not come under those which have already been 
 enumerated as rotations, expansions, and undulations. In 
 the case of both electrical and magnetical actions, we find 
 that the bodies subjected thereto do exhibit strikingly 
 different motions, which have been called polar ; and we 
 therefore conclude that polar motions are the characteristic 
 phenomena produced by the correlative forces of electri- 
 city and magnetism. We cannot, in every case, demon- 
 
 L 4 
 
152 ELECTRICITY AND MAGNETISM. 
 
 strate that in polar motions both these forces are concerned, 
 but we know the very general fact, that when force 
 manifests itself it can only be because it is in a plus or 
 dynamical state ; whilst the other force is rendered latent 
 or equalised by a portion of the plus force, up to which 
 point both forces are necessarily unknown, as neither is in 
 a condition to function. So that, although it cannot be 
 always proved, we are justified in concluding that all 
 polar motions are dualisms or compounds of electricity 
 and magnetism. The science, therefore, which comprises 
 the consideration of these forces, as astronomy does those 
 of gravitation and centrifugy, must be the science of polar 
 motions, which may be called Polarity. It may be ob- 
 jected to this term that it is already associated in our 
 minds with an idea of antagonism, which is common to all 
 physical phenomena ; if so, another may be invented : but 
 it would seem to be preferable to abandon the use of this 
 term in a sense which is at best very confused, and to 
 restrict it to the above-mentioned definite purpose. 
 
153 
 
 CHAP. VI. 
 
 CHEMICAL SUBSTANCES, DUALISMS OF PHYSICAL AND 
 CHEMICAL POWEKS. 
 
 The Union of dissimilar Substances, the characteristic of Chemical 
 Action. This a kind of Attraction. Does not act indiscriminately 
 between all Bodies: but is elective. This Attractive Force called 
 Affinity. Chemical Affinity and Electricity supposed to be identical. 
 This Opinion advocated by Davy, Berzelius, and Faraday. 
 Comte regards this as confounding the Auxiliary with the Pheno- 
 menon. Electricity is a diffusive, decomposing Force; Affinity a 
 condensing, combining Force : can such Opposites be identical ? 
 The mutual Convertibility of these Forces more apparent than real. 
 Various Definitions of Chemistry. Chemical Elements, their Nature. 
 The Weight and Volume of each Element specific. The Elements 
 not Multiples of Hydrogen. Predisposing Affinity. Chemical 
 Compounds all Binaries or Dualisms. Chemical Notations. The 
 Duplication of Atoms an important Innovation. Allotropy. This 
 State of Elements not permanent. Duplication of Atoms re- 
 markably indestructible. The Hydrocarbons, basic or neutral, 
 electro-negative and electro-positive; their Combinations as quasi- 
 elements, like Cyanogen. The typal and basic Combinations of 
 Nitrogen. Conclusion. 
 
 HITHERTO our attention has been solely occupied with 
 the consideration of the physical powers, which are uni- 
 versal or cosmical forces, pervading all material bodies ; 
 for matter itself, or physical substance, is a dualism of 
 these powers. Various as physical phenomena are, 
 throughout the different departments of nature, they all 
 
154 CHEMICAL ELEMENTS, DUALISMS 
 
 depend on the modes or phases of physical powers, which 
 function as peculiar kinds of material motions ; thus, we 
 have central motions, undulations, and polarisations, but 
 all are modifications of one and the same physical motion, 
 or change of position in space. 
 
 Chemical, not physical, changes are, however, now to 
 form the subject of our inquiry ; and we shall have to 
 deal with more complex dualisms of powers. Dualisms, 
 not of two simple antagonistic powers which alone were 
 capable of interchanging their relations in such a protean 
 manner, so as to produce an infinity of phenomena ; but 
 dualisms, the basic or ponderable part of which consists 
 of the more simple physical dualism actuated by specific 
 influences or chemical powers. 
 
 But before entering on this subject let us take a hasty 
 glance at the prevailing opinions concerning chemical 
 force, and concerning the character and object of chemis- 
 try ; an introduction which will render our view more 
 intelligible. 
 
 The first and most obvious characteristic of chemical 
 force is its tendency to draw together and unite dissimilar 
 substances, so as to form new and homogeneous com- 
 pounds. It was by a comparison of the changes which 
 attend chemical actions that Newton was led to conclude 
 that chemical combinations cannot be conceived of in any 
 other way than as an attraction of particles. This notion 
 was much opposed, particularly in France ; but it at last 
 gained ground, and the term affinity was adopted instead 
 of that of attraction. There can be but little doubt that 
 chemical force is essentially an attractive force ; but it 
 possesses something more than this generic character, it 
 
OF PHYSICAL AND SPECIFIC POWERS. 155 
 
 has also a peculiar or specific difference ; it is not only an 
 attractive, but also an elective force, for it does not unite 
 all substances indiscriminately, but as an elective affinity 
 it manifests a preference in the order of its operations. 
 At the end of the last century the doctrine of elective 
 affinity had assumed a systematic form, when it was 
 assailed by Berthollet, who maintained that affinity is not 
 elective, but depends upon the relative quantities of the 
 substances employed, and other physical conditions. After 
 a long discussion it is, however, now decided that although 
 affinity is greatly modified by various circumstances, and 
 even altogether suspended, yet when it can take place it 
 is exerted with different degrees of energy and preferen- 
 tially between some substances to the exclusion of others. 
 " The close connection*," observes the author of the " Phi- 
 losophy of the Inductive Sciences," " between chemical 
 affinity and the crystalline attraction of elements cannot 
 be overlooked. The forces which hold together the ele- 
 ments of a crystal of alum are the same forces which make 
 it a crystal. There is no distinguishing between the two 
 sets of forces." " The regular forms of bodies," says 
 Berzelius, "suppose a polarity which can be no other 
 than an electric or magnetic polarity. This being so 
 seemingly inevitable, we might expect to find the electric 
 forces manifesting some relation to the definite directions 
 of crystalline forms. Mr. Faraday tried, but in vain, to 
 detect some such relation." It is now the general opinion 
 that chemical force and electricity are identical: and if 
 affinity and cohesion are the same force, it fallows that 
 
 * Philosophy of the Inductive Sciences, vol. i. p. 353. 
 
156 CHEMICAL ELEMENTS, DUALISMS 
 
 crystalline force and electricity must also be identical ; 
 since things that are equal to a third are equal to one an- 
 other. The recent investigations of Faraday concerning 
 magne-crystallic force may seem to sanction the idea that 
 polarity is concerned in both cases : there is much in 
 common between crystalline and polar forces, but, as we 
 have already remarked on this subject in the last chapter, 
 we need not now renew the discussion. 
 
 In modern times, the identity of chemical affinity and 
 electricity has had many eminent supporters. Davy 
 claimed the credit of having first advanced this doctrine ; 
 but this, whether justly or not, has been disputed : he cer- 
 tainly was, however, the first who gave the hypothesis a 
 tangible form, and supported it by a series of brilliant 
 experiments. Since then, Berzelius has most ably advo- 
 cated this opinion, and reduced it to a more definite 
 system. And Faraday, in his valuable "Researches in 
 Electricity," has completed the inquiry by demonstrating 
 the equivalence of chemical and electrical actions ; a fact 
 which seems to have carried with it such conviction, that 
 the doctrine is now very generally received as an esta- 
 blished truth. 
 
 The electro-chemical hypothesis is not, however, univer- 
 sally acknowledged. " Though chemistry," says Comte*, 
 " is united to physics by electricity more than by any other 
 agency, it must yet be remembered that the two sciences 
 are distinct, and that there should be no confounding of 
 chemical with electrical phenomena. When our prede- 
 cessors regarded heat as the chief agent in composition 
 
 * Positive Philosophy, vol. i. p. 335 et seq. 
 
OF PHYSICAL AND SPECIFIC POWERS. 157 
 
 and decomposition, they did not pervert such a considera- 
 tion to the point of assimilating chemical to thermotic 
 effects. We, however, confound the auxiliary with the 
 phenomenon itself; and pervert chemistry by confounding 
 it with electrology. Berzelius has frankly declared that 
 cohesion, properly so called, admits of no electrical ex- 
 planation, nor is affinity or the tendency to combination 
 any better explained by the electro-chemical theory. 
 Electrical phenomena in physics are eminently general, 
 offering only differences of intensity in different bodies ; 
 whereas chemical phenomena are essentially special or 
 elective, and therefore every attempt to make chemistry, as 
 a whole, enter into any branch of physics, is thoroughly 
 anti-scientific." This is strongly expressed, but it con- 
 tains an important truth sustained by sound reasoning. 
 Electricity is a phase of the universal force repulsion, one 
 of the correlative forces of the physical dualism ; and the 
 physical forces only function in various kinds of motion : 
 whereas chemical force or affinity is not a physical force ; 
 it does not operate in any kind of motion) but in the 
 combination of heterogeneous molecules. So far from 
 electricity and affinity being identical forces, they seem 
 rather to be diametrically opposite : the one being emi- 
 nently an expanding, heating, and dissipating force ; the 
 other a condensing and aggregating force. 
 
 Before quitting this subject, there remains to be noticed 
 another, and the latest opinion concerning the nature of 
 chemical force. Grove considers this force as not only 
 identical with electricity, but also with all the other 
 physical forces ; on the ground, as already stated, that they 
 are all capable of mutual conversion into each other. It 
 
158 CHEMICAL ELEMENTS, DUALISMS 
 
 is not very surprising that in electrolysis, a definite amount 
 of electricity should liberate a corresponding equivalent of 
 chemical elements ; or that the union of -these elements 
 should evolve electricity. The forces concerned are the 
 antagonists of one another, the one in direction of attrac- 
 tion, the other of repulsion ; and it therefore follows that 
 when chemical union takes place it is accompanied by an 
 evolution of repulsion, which under certain conditions mani- 
 fests itself as polar or electrical motions : and in turn 
 when electricity operates, its repulsive action on the com- 
 pound produces a state unfavourable to union, and so its 
 chemical constituents are set at liberty. In short, such 
 cases are only instances of action and reaction, which 
 necessarily imply the co-operation of opposite influences : 
 and if so, it follows from this circumstance alone that 
 electrical and chemical forces are antithetic, having nothing 
 in common. 
 
 Since the conception which has been hitherto formed 
 concerning the character of chemical force is so indefinite, 
 it is not to be wondered at that the various attempts 
 which have been made to define chemistry have proved in- 
 adequate to express the nature and the objects of the science. 
 One of the best definitions of chemistry is that of Dr. 
 Thomson, in his system, now out of date : " Chemistry," 
 he says, (< is a science, the object of which is to determine 
 the constituents of bodies, and the laws which regulate 
 their combinations." Turning to a few modern books 
 within our reach, we read in PeschePs "Physics," that 
 "chemical attraction is the exercise of the molecular 
 forces on the actions of dissimilar bodies." " Chemistry," 
 says ScofFern, " is the science which investigates the quality 
 
OF PHYSICAL AND SPECIFIC POWERS. 159 
 
 and constitution of matter in all its relations, except/ 
 those affecting visible motion." Comte's definition 
 chemistry is that it " relates to the laws of composij 
 and decomposition, which result from the molecular i, 
 specific mutual action of different substances." Lastly 
 we look in vain for information thereon in Professor 
 Miller's recent work on this science ; perhaps an inten- 
 tional omission, considering chemistry as yet incapable of 
 being defined. As Comte* has observed, " every science 
 falls short of its definition ; but a real definition is the 
 first evidence that science has attained some consistency ^ 
 for it then measures its own advancement from one epoch 
 to another ; and it always keeps inquirers in a right 
 direction, and supports them in a philosophic progress." 
 Now, during the inductive formation of a science, a real 
 definition can only be a happy anticipation ; but when a 
 science has arrived at maturity, it and its definition ought 
 to be the equivalent of each other, the reciprocally con- 
 vertible terms of an identical proposition. 
 
 Such is a brief statement concerning the nature of 
 chemical force and of chemical science as now generally 
 understood, and which, as may have been gathered from 
 our remarks, we are not prepared to accept as satisfactory. 
 Whether we have anything better to offer remains to be 
 decided, when we have submitted our views thereon ; but 
 whether approved of or not, they have resulted from, and 
 are in accordance with, the principles of our universal 
 system. 
 
 Guided by the analogy of the physical sciences, that is 
 
 * Positive Philosophy, vol. i. p. 294. 
 
ICO CHEMICAL ELEMENTS, DUALISMS 
 
 of those sciences which treat of the varied motions of 
 material bodies, chemistry may be defined as the science 
 or systematic knowledge of chemical substances, and of 
 their combining actions and reactions on each other. Just 
 as material motions from the subject-matter of physics, so 
 material combinations are the objects of chemistry : these 
 two branches of knowledge are perfectly distinct. Phy- 
 sical attractions and repulsions occur in all natural bodies; 
 for all are fundamentally material or physical : and thus it 
 happens that all chemical substances possess characteristic 
 physical properties. But the peculiar, or specific, proper- 
 ties of chemical substances must not be confounded with 
 the generic or physical : we treat not now of the latter, 
 but of those differential attributes, derived from or belong- 
 ing to the specific powers, one of which forms a con- 
 stituent of every chemical element. 
 
 All chemical substances have been resolved into a com- 
 paratively few simple bodies or elements, as they are called. 
 Elementary substances are only conventionally accepted 
 as simple, as long as they remain undecomposable ; and so 
 it has come to pass that not only substances supposed to 
 be simple have been proved to be otherwise, but even 
 those which at one time were deemed compounds are 
 now acknowledged as chemical elements. This at first 
 sight would seem to involve the subject in utter confusion ; 
 but it has not practically had this effect : it necessarily 
 requires occasional changes, but these are easily made, 
 without deranging the entire system. When, therefore, 
 we hereafter state that elements are individually actuated 
 by their respective specific force, we do so under the 
 proviso that they are indeed bond fide elements . should 
 
OF PHYSICAL AND SPECIFIC POWERS. 161 
 
 such, however* prove to be not simple, but combinations 
 of elements, then that which was supposed to be a simple 
 force, becomes a composition of specific forces ; our know- 
 ledge thus becomes more accurate, without any sacrifice of 
 principle. 
 
 What then is a chemical element ? It is, like all other 
 natural bodies, a dualism of powers. One of its correla- 
 tive powers is a complex power, matter, the physical dual- 
 ism ; it is the quantitative basis or body of the element, 
 and thence its physical properties: whilst the other cor- 
 relative power is the actuating qualitative principle, which 
 imparts to the element its specific chemical character. 
 Here then we see a grand advance in the system of nature: 
 the dualisms are no longer varied modes of the same binary 
 and universal powers, and as such universally related as 
 parts or units of the same whole, but as chemical elements 
 they each possess an individuality, which is not communi- 
 cable. A mass and a molecule of matter only vary in 
 magnitude; and however their figurative forms may 
 be modified, or however diversified the manner and direc- 
 tions of their movements ; in short, whatever may be their 
 differences, they are parts of one and the same dualism of 
 physical powers, attraction and repulsion : not so the 
 chemical elements, however they are combined together, 
 and whatever may be the multitude of complications 
 resulting therefrom, each and every element retains its 
 individuality, and phoenix- like may be restored again to 
 its pristine condition. 
 
 Each element, then, has its specific power : and thus we 
 have to admit the existence of many chemical powers ; 
 whilst physical powers are only two, universal attraction 
 
 M 
 
162 CHEMICAL ELEMENTS, DUALISMS 
 
 and repulsion. Substance, as already stated, is the logical 
 correlation of its correlatives, quantity and quality: phy- 
 sical substance, or matter, is a dualism of attractive and 
 repulsive powers ; and chemical substance is a dualism of 
 matter and chemical power. Every chemical element, as 
 a peculiar substance, has a material body actuated by a 
 specific energy : but although the bodies of all the elements 
 are material, it does not follow that they are perfectly 
 alike in all cases : and so it is found that they all differ 
 from each other in quantity, each element having a body 
 of a peculiar and definite weight. The reason of this 
 difference is, we conceive, that the specific force of each 
 element is capable, like the specific vital principles of 
 organisms, of appropriating a given number of material 
 units, or atoms, and arranging them in the construction of 
 its own body or molecule : and in the exercise of chemical 
 force, according to its innate rational law, it assimilates 
 only a definite number of atoms to form its peculiar atomic 
 weight; and symmetrically disposes these atoms, in a more 
 or less regular manner, to constitute its specific volume. 
 And as these specific weights and volumes vary for each 
 chemical element, so do their physical properties exhibit 
 corresponding variations. So likewise in the characters of 
 the very elements themselves, that is, of their specific 
 forces, we perceive and may anticipate the nature of 
 chemical functions generally : they are definite, elective, 
 and eminently attractive ; joining together and condensing 
 atoms into compounds. 
 
 Chemical powers, then, when operative, function in 
 combination, which partakes largely of the nature of 
 attraction, but is distinguished therefrom by a specific 
 
OF PHYSICAL AND SPECIFIC POWERS. 163 
 
 peculiarity. These powers may be regarded as numerous 
 species of the genus attraction ; each of them possessing 
 the generic character, together with some peculiarity, 
 which marks their differences as species; and in this 
 manner, we conceive, the universal and particular attractive 
 powers, physical attraction and chemical forces, may be 
 capable of systematic arrangement. And since chemical 
 powers are thus seen to act in the direction of attraction, 
 that is, having a uniting and condensing tendency, we can 
 understand how sometimes these different forces may 
 promote each other's operations; and at others be unfavour- 
 able : all depends on the manner of their concurrence. 
 
 This view of the constitution of chemical elements may 
 seem at first sight very similar to one which has been pro- 
 pounded by the Reverend Dr. Macvicar, in his " Elements 
 of the Economy of Nature," an ingenious and very sug- 
 gestive work published three years ago; the subject of 
 which has just been laid before the British Association at 
 Aberdeen, and reported as follows : te Suppose an ana- 
 logy of function in the entire series of chemical agents, 
 implying an analogy of corresponding structure. The 
 only constituent atom, or truly simple element, is some- 
 thing lighter than hydrogen, and a physical rather than a 
 recognised chemical agent. The universal ether, an 
 ancient doctrine, now sanctioned by modern science, con- 
 stitutes the medium of light and radiant heat, and is com- 
 posed of particles all similar to each other, and animated 
 by attractive and repulsive forces, like the molecules of 
 common bodies. Affirming the query of Newton as to 
 whether the molecules of dense bodies may not be com- 
 posed of particles of the medium of light, a molecular 
 
 M 2 
 
164 CHEMICAL ELEMENTS, DUALISMS 
 
 theory resulted, which satisfied and explained, to a 
 wonderful extent, the well-known atomic weights of 
 chemical agents. The principle on which Dr. Macvicar 
 conducts his synthesis of molecules is that of statical equi- 
 librium or symmetry. The first in the series is a molecule 
 composed of five particles of light or ether ; three to form 
 an equator and two to form the poles. This molecule, 
 when viewed in relation to its own exquisite mechanical 
 structure, and to the medium of light in which it continues 
 to exist, gives as its mechanical and optical properties the 
 same as those which characterise hydrogen. And in this 
 manner, according to the number of atoms of ether, each 
 chemical element is formed." 
 
 Our notion concerning chemical elements was arrived 
 at long before we became acquainted with the above 
 views ; but as a point of priority this is of no consequence, 
 as there is a great difference between us. We conceive, 
 as Dr. Macvicar does, that the atoms of ether or pure 
 physical substance, according to their definite number, 
 constitute the weight of each element, and that the crys- 
 talline form of each element depends upon the symmetrical 
 arrangement of the etherial atoms : and here, if we have 
 not misapprehended the statement, his explanation ends ; 
 a definite structure implying a corresponding chemical 
 agent. But according to our view, this definite structure 
 is only the body of each element, the lasis or reacting 
 principle in the dualism ; the actuating principle which 
 determines the weight and volume of the body being a 
 specific force, different from all physical forces: we seem 
 therefore, to agree, when the question is only viewed on 
 the side of its ponderable matter ; but this is, we think, 
 
OF PHYSICAL AND SPECIFIC POWERS. 165 
 
 only one half of the question ; the elements are not only 
 physical, but also chemical, a composition of co-existent 
 and opposite forces. 
 
 From what has been now stated, we are prepared to 
 understand why the chemical elements are not multiples 
 of hydrogen ; the lightest of the elements, and the one 
 \\hich is generally adopted as the atomic standard of unity. 
 Prout, indeed, maintained, with great ability, that the 
 elements are multiples of hydrogen; but the elaborate 
 experiments of Berzelius, Turner, and others brought 
 forward so many exceptions thereto, that this notion was 
 abandoned ; very recently, however, strenuous exertions 
 have been made to revive Prout's theory, but there still 
 remain so many outstanding facts, that the probability of 
 their success is very remote. In the mean time, hydrogen 
 can only be accepted as a relative unit, as a standard with 
 which the atomic weights of all the other elements may 
 be compared. Could it be determined how many atoms 
 of pure matter, or ether, entered into the composition of 
 a chemical atom or molecule of hydrogen, and the actual 
 weight of such atoms, our knowledge on this subject 
 would be perfect : but we must rest content with a con- 
 ventional standard. Let it then suffice to assume, that 
 each molecule of hydrogen is composed of one hundred 
 or a thousand atoms of ether ; and if the cyphers be 
 marked off as decimal-points, there would, on this plan, 
 be no alteration in the notation of the present hydrogen- 
 scale; the decimals, however, would not be read as the 
 fractional parts of a hydrogen atom, but as integrant 
 material atoms, thereby removing the anomaly of dividing 
 atoms, which seems to have suggested the notion that all 
 
 M 3 
 
166 CHEMICAL ELEMENTS, DUALISMS 
 
 the elements must be multiples of hydrogen. Such a 
 notion is well avoided, for it is tantamount to the asser- 
 tion that all substances are ultimately composed of 
 hydrogen ; and it therefore also implies the possibility of 
 the transmutation of bodies : a doctrine inconsistent 
 with the stability of nature, and incompatible with a 
 science of chemistry. 
 
 When chemical substances are in a gaseous state, they 
 have been found to have a definite relation towards each 
 other in their volumes ; combining volume for volume or 
 some multiple of a volume. In many cases, also, the 
 specific gravity of a gaseous element corresponds with the 
 atomic weight, hydrogen being unity in both instances : 
 and, indeed, when we consider how predominant repulsion 
 is in the gaseous state, and the uniformity of the law of 
 expansion in all gases, it might have been expected that 
 atomic weights and specific gravities would have been 
 universally identical. Some have maintained that it is so, 
 and that this ought to be the regulating principle in 
 determining atomic weights. In his (f Radical Theory of 
 Chemistry," Mr. Griffin has extensively illustrated this 
 subject ; and has imparted to his argument, at least, the 
 appearance of probability. Having, however, carefully 
 weighed it, we are not disposed to accept it ; for, through- 
 out nature, whilst considerable reliance may be placed on 
 the definite character of weight, there is no dependance 
 on that of volume, it is so very variable : and not only so, 
 but the very elements that require great alterations, in 
 the scale of chemical equivalents, in order to maintain 
 the aforesaid identity, are the ones which are subject to 
 allotropic changes, such as oxygen, sulphur, and phospho- 
 
OF PHYSICAL AND SPECIFIC POWERS. 167 
 
 rus: and therefore we are inclined to accept them as 
 departures from the very prevalent condition, that the 
 specific gravities and atomic weights of gases are identical ; 
 and not as affording sufficient grounds for the duplication 
 of oxygen's atomic weight. This conclusion, the doubling 
 the oxygen-equivalent, however, has been arrived at on 
 other considerations ; and is, at the present day, very 
 generally adopted : but of this more hereafter. 
 
 Before entering on the consideration of chemical actions 
 and reactions, let us endeavour to understand clearly how 
 chemical elements stand in relation to each other. In the 
 case of physical dualisms, the antagonistic forces are in- 
 dissolubly conjoined in the same body ; they cannot exist 
 in an insulated state, as distinct individuals : and the only 
 way in which their individuality can be inferred, is by 
 either of them being dynamically predominant, so as to 
 impart its characteristic to the resulting phenomenon. 
 Now in the case of chemical substances or dualisms, this 
 is very different ; even the single elements have a complex 
 constitution, as already stated, and as dualisms can enjoy 
 an independent existence. But still each element, as a 
 single chemical force, as a unit of power, cannot function; 
 it cannot act and react on itself: therefore there must be 
 a concurrence of two or more elements, before there can 
 be any combination, any subject-matter for chemistry. 
 We must know the elements, or we cannot tell what 
 forces are concerned in chemical phenomena; but the 
 knowledge of the latter is the more immediate subject of 
 the science. 
 
 When two chemical elements are brought within the 
 sphere of action, they combine to form a compound ; one 
 
 M 4 
 
168 CHEMICAL ELEMENTS, DUALISMS 
 
 of these performs the part of the basic or reacting force in 
 the new dualism ; and the other, that of the specific or 
 typal force ; so that the resulting compound is a compo- 
 sition of forces, which, in this case, can be demonstrated 
 by the analytical separation of its constituents, and their 
 exhibition in an insulated state. Call to mind what has 
 already been said concerning the relations of physical 
 forces in the different states of matter ; and the same will 
 be found to hold good in the condition of chemical forces, 
 when in compounds their ratios vary. Some elements 
 manifest in an eminent degree a basic character ; whilst 
 others have a stronger tendency to become typal: but all, 
 as regards the entire series, indicate such a relationship, 
 that in respect to any given element, some are basic and 
 others typal, according as they come before or after one 
 another in the series ; a characteristic so well marked, as 
 to have suggested the arrangement of Berzelius, the 
 electro-positive and electro-negative elements following 
 a corresponding order. 
 
 Binary combinations thus formed become in their turn 
 constituents of new compounds ; either the basic or typal 
 force may be compound, and the other simple ; or both 
 correlative forces may be compound. And these com- 
 pounds also may unite into still more complex combina.- 
 tions ; a process which may be carried to many repetitions, 
 involving compounds within compounds, but always fol- 
 lowing the same archetypal principle as the elements. 
 Thus an acid and an alkali may have very complicated 
 constitutions, and yet combine in the ratio of one equi- 
 valent each to form a salt ; the basic and typal constituents 
 of which are related to each other in the same manner as 
 
OF PHYSICAL AND SPECIFIC POWERS. 169 
 
 in the simplest oxysalt, or as in a binary haloid. In all 
 these cases, the constituent forces being equal, the salts 
 are neutral ; that is, neither constituent imparts its cha- 
 racteristics to the compound, which as a tertium quid has 
 its own individuality : but when either the typal or the 
 basic force is in excess, say as a double equivalent, then 
 the resulting compound manifests the character of the 
 predominant constituent. This remark reminds us of an 
 observation of J. S. Mill* concerning the character of 
 chemistry ; and we will notice it here, as it serves to 
 elucidate the nature of chemical actions. " The chemical 
 combination of two substances," he says, " produces a third 
 substance with properties entirely different from those of 
 either of the two substances separately, or both of them 
 taken together. This explains why mechanics is a de- 
 ductive or demonstrative science, and chemistry not. In 
 the one, we can compute the effects of all combinations of 
 causes from the laws which govern those causes when 
 acting separately; because they continue to observe the 
 same laws when in combination which they observed when 
 separate. Not so in the phenomena which are the pecu- 
 liar subject of the science of chemistry." Again, " In 
 mechanics if a body be propelled in two directions by two 
 forces, it moves in a given time exactly as far as the two 
 forces would separately have carried it ; and is left precisely 
 where it would have arrived if it had been acted upon 
 first by one, and afterwards by the other force ; which law 
 is called the composition of forces." 
 
 According to our view of the subject, this disparage 
 
 * System of Logic, vol. i. p. 400, 
 
170 CHEMICAL ELEMENTS, DUALISMS 
 
 rnent of chemistry has arisen from a misapprehension of 
 chemical phenomena ; the cases are not exactly parallel, 
 which makes the difference more apparent than real. In 
 the case of mechanics, the antagonistic forces are applied 
 to a given body ; in that of chemistry they are themselves 
 only regarded as making up the body itself: apply the 
 chemical forces through the medium of a given body ; and 
 the results will be perfectly analogous. Add an equivalent 
 of sulphuric acid to an equivalent of sulphate of soda, and 
 we get bisulphate of soda ; a combination as far advanced 
 as a single force can effect in the change of composition : 
 next add thereto an equivalent of soda, and a similar 
 amount of change will be produced in the opposite 
 direction. Lastly, act on the sulphate of soda by adding 
 equivalents both of acid and alkali, not successively but 
 simultaneously, and the same result will be obtained, a 
 neutral salt ; precisely what would have been arrived at, if 
 it had been acted on first by one force and afterwards by 
 the other: in short, it is a composition of forces, in which 
 the basic and typal forces, though different, are neverthe- 
 less co-existent in all their entirety. 
 
 The predisposing affinity of one substance for another, 
 (for a compound which does not as yet exist in the mixture, 
 but which tends to become formed,) has been ably advo- 
 cated by Berzelius and others, and applied to the explana- 
 tion of many perplexing facts. Comte ridicules this 
 opinion as metaphysical and incomprehensible; forgetting 
 that he himself sanctions a common expression in rational 
 mechanics, " that forces are only motions produced or 
 tending to be produced." Some of these facts are certainly 
 at present inexplicable, but many of them might be solved 
 
OF PHYSICAL AND SPECIFIC POWERS. 171 
 
 without having resort to catalysis, or any other unknown 
 mode of action. For instance, the evolution of hydrogen 
 gas by the action of dilute sulphuric acid on iron is 
 commonly adduced as a case of predisposing affinity. We 
 know that iron decomposes water at a high temperature, 
 combining with its oxygen and liberating the hydrogen ; 
 all therefore that is required to enable it to produce the 
 ^sgmo effect at a low temperature, is an additional force, 
 just sufficient to turn the scale between action and no 
 action ; and such a force may exist in the state of con- 
 densation of the combined water in the hydrated sulphuric 
 acid ; arid if so the water may be directly decomposed by 
 the iron, and the resulting oxide uniting with the acid, 
 may induce an increase of compressive or aggregating force 
 which would tend also to facilitate the action of the 
 predisposing affinity. 
 
 The physical condition of chemical substances forms a 
 most important consideration in most chemical phenomena ; 
 hence, one of the oldest maxims is, " that bodies do not 
 act on each other unless in a state of solution." This is not 
 universally true ; but so generally acknowledged in prac- 
 tice, that by far the greater number of re-agents are kept 
 ready at hand in the liquid state. The reason of this 
 is sufficiently evident ; the statical condition of liquids 
 permits their respective molecules to be easily intermingled 
 and brought within the sphere of mutual action. Gases 
 also freely diffuse throughout each other, but their mole- 
 cules being far apart is not a condition favourable to com- 
 bination ; the molecules of solids, on the other hand, are so 
 firmly and closely aggregated, that unless their cohesion 
 be physically overcome, chemical forces cannot become 
 
172 CHEMICAL ELEMENTS, DUALISMS 
 
 operative ; and thus it is that heat is such a valuable agent 
 in promoting combinations. From this statement it must 
 not be concluded, that the energy of chemical forces is 
 feeble ; but that the different conditions of bodies more or 
 less modify their action : for chemical affinity between some 
 gases is so intense as to reduce these substances to the liquid 
 and even the solid state, accompanied by a disengagement 
 or expulsion of heat ; an effect which the coercion of the 
 greatest cold and mechanical pressure, which ingenuity 
 can devise, has failed to accomplish. 
 
 According to the notion above advocated, that all chemical 
 compounds, whether of simple or complex substances, are all 
 binaries or dualisms, their constitution may be expressed 
 by the simple formula of our universal correlation, 
 
 A + B = AB. 
 
 At present, there are a great many ways of expressing the 
 same compound, in consequence of the difference of opinion 
 concerning its constitution. For instance, water was long 
 regarded as a binary, atom for atom, of oxygen and hy- 
 drogen, and as such, formulated as HO ; which agrees 
 well with our formula, intimating that it is a neutral com- 
 pound, in which its constituents, H 4- O, are co-existent 
 and opposite forces. But now, water is more commonly 
 written as H 2 ; or, according to the notation of Laurent 
 
 TT 
 
 and Gerhardt, as rrO ; the equivalence with the original 
 
 notation being maintained, by doubling the atomic weight 
 of oxygen", thus making it, on the hydrogen scale, 16 in- 
 stead of 8, which number has been so long in use in this 
 country. The principal reason for this change seems to 
 
OF PHYSICAL AND SPECIFIC POWERS. 173 
 
 rest on the fact, that water consists by measure of t\vo 
 volumes of hydrogen and one of oxygen, condensed into 
 t\vo volumes : a circumstance which we are inclined to 
 consider as unimportant, for throughout the range of 
 chemical substances, we find weight a permanent, and 
 volume a variable condition ; and which ought not for a 
 moment to be put into competition with the comport- 
 ment of water under electrolysis, which strongly supports 
 the opinion that it is a compound of atom for atom, and 
 not two of hydrogen and one of oxygen, which the new 
 theory maintains. 
 
 Besides, this theory introduces a greater complication, 
 both in the composition of substances, and in their formulae ; 
 which ought, if possible, to be always avoided : and unless 
 we are greatly mistaken, to go no farther than the other 
 compound of oxygen and hydrogen, binoxide or peroxide of 
 hydrogen, an incongruity meets us, or at least an appearance 
 which is inconsistent with the character of the compound. 
 
 If water be H 2 O or ^ O, then is this peroxide, H 2 2 or 
 
 TT 
 
 TT O 2 ; this notation indicates that the constituents are in 
 n 
 
 a state of equilibrium, two equivalents of one force united 
 with two of the other force ; whereas the substance is in 
 a highly dynamical state, energetically acting on and impart- 
 ing oxygen to, other bodies ; and is, therefore, much better 
 symbolised by HO 2 , according to the old notation. 
 
 Moreover, on this view of Gerhardt and others, many 
 other equivalents besides oxygen must be doubled ; more, 
 we believe, than have hitherto been deemed necessary : 
 and then all the metallic bases of the oxysalts must be 
 
174 CHEMICAL ELEMENTS, DUALISMS 
 
 supposed to exist in two proportions, and denoted, accord- 
 ing to the analogy of water ; a complication, which is, we 
 think, much better avoided. Now the two basic atoms, in 
 this trinal system, are supposed to be incapable of existing 
 in an uncombined state, as single atoms ; but that whilst 
 in combination they can be disunited, so as to be separately 
 replaced by other substances : assumption on assumption, 
 not resting on facts, but framed to suit the hypothesis. 
 Gerhardt's duplication of metallic atoms in protoxides, is 
 said to give a satisfactory explanation of the hydrated and 
 anhydrous states of these substances. Thus potassium, 
 
 TT 
 
 K, acts on water, rrO, replaces one equivalent of hy- 
 
 K 
 
 drogen and becomes jrO, or hydrate of potassa : but this 
 
 is impossible, according to the hypothesis ; for oxygen O, is 
 but one atom, and K H- ^ of O, or II + ^ of O, can neither 
 
 represent potassa nor water, and therefore jrO cannot be 
 
 hydrate of potassa. And not only so, but we are told that 
 hydrogen as H cannot exist in an insulated state, but 
 
 TT 
 
 that it must be evolved as TT. But this dilemma is escaped 
 
 by supposing that one atom of potassium cannot decompose 
 water, it must, like that of hydrogen in water, be employed 
 
 as two atoms JT-, and then the formula of action and reaction 
 
 will stand as follows, 2(^0) + j| = |o + 04 ^' 
 
 This begging the question is a roundabout way of evading 
 a difficulty ; and after all, the notation is much inferior to 
 the old method, 2 HO + K = KO + HO + H. We cannot 
 
OF PHYSICAL AND SPECIFIC POWERS. 175 
 
 now trace out this trinal notation ; but we have followed 
 it out in all its bearings : in some cases, its solutions are 
 very plausible; but they are outbalanced by a greater 
 number of objections. 
 
 In making these remarks, it must not be supposed that 
 we reject the notion of the duplication of atoms : the du- 
 plication, many times repeated, not only of simple, but 
 also of compound molecules, seems to be well established ; 
 and is in accordance with the varying magnitudes of 
 molecular masses in physics. That the same element, or 
 the same compound, should be aggregated into molecules, 
 consisting of two or more atoms of the same kind ; and 
 that as such they should act not only physically, but 
 also chemically, with varying degrees of energy, is what 
 can be easily imagined; but since analysis has established 
 the fact, it must not be questioned : what we have to do 
 is to study the phenomena under these complicated re- 
 lations. The modification which oxygen, sulphur, and 
 phosphorus undergo in some conditions of their molecular 
 arrangement, seems to depend on some such duplications 
 of their atoms, or of some internal disposition in their 
 individual atoms, called allotropy. Schonbein, a very 
 successful investigator of this subject, has given the name 
 of ozone to the allotropic form of oxygen. Its properties 
 are different from those of ordinary oxygen ; but still the 
 difference is only in the degree of energy, such as might 
 be expected from the approximation of the oxygen-atoms 
 by some condensing influence. 
 
 Whether oxygen gas does undergo any change of 
 volume during the production of ozone, has not been 
 
176 CHEMICAL ELEMENTS, DUALISMS 
 
 recorded, as far as we can ascertain ; though it is probable 
 that its molecules are more closely arranged : an increased 
 density, as occurs in allotropic phosphorus and sulphur, 
 would explain the alteration of its properties. It is pos- 
 sible that ozone may be produced during the action of a 
 platinum plate on oxygen gas. Condensation doubtless 
 takes place in this case; and if this be accompanied by 
 the formation of ozone, the increased facility of combi- 
 nation which the mixture of oxygen and hydrogen gases 
 experiences would be accounted for. The fact could be 
 easily determined, either by observing the change of 
 volume in the oxygen gas ; or, what would be still better, 
 by placing the ozone-test in contact with the platinum. 
 
 Ozone resembles in many respects deutoxide of hydrogen, 
 but according to the experiments of Schonbein, it does 
 not contain any hydrogen ; indeed the properties of the 
 hydrogen-compound are only those of liquid oxygen, such 
 as an excess of this element might impart. 
 
 In all such cases of metamorphosis, there is no trans- 
 mutation of one element into another, but only a physical 
 change of structure, which so far modifies their chemical 
 properties, exalting or depressing them, according to cir- 
 cumstances : in all such cases, however, there is one thing 
 in common, the allotropic condition is subverted at high 
 temperatures ; the repulsive force so separating the atoms 
 as to enable them to assume their normal arrangement. 
 At least, such is the behaviour of the elements in respect 
 to heat when in an allotropic state ; but if the duplication 
 of the atoms of elements in compounds be an allotropic 
 condition, it is of a much more permanent character, in 
 
OF PHYSICAL AND SPECIFIC POWERS. 177 
 
 consequence of the presence of other elements ; for such 
 have often a remarkable indestructibility. 
 
 The double atoms of the elements enter into the com- 
 position of some of the most interesting combinations; 
 and of these none is more important, or of more frequent 
 occurrence, than the duplications of carbon. This element, 
 as C 2 , unites with nitrogen forming cyanogen, C 2 N; a 
 union so intimate and enduring, that this substance enters 
 into a great variety of combinations, as a quasi-clement 
 analogous to chlorine; and not only cyanogen, but also 
 its compounds, are capable of duplication : thus we have 
 Cy, Cy 2 , Cy 3 ; and also Cy O, (CyO) 2 , (CyO) 3 , the cyanic, 
 fulminic, and cyanuric acids. So likewise carbon, as C 2 , 
 may assume also a typal position in compounds, whilst 
 the basic constituent may also be duplicated, as in the 
 hydrocarbons, H 2 C 2 . The hydrocarbons are of frequent 
 occurrence in organic compounds, and are capable of 
 undergoing duplications to an astonishing number of 
 repetitions : each addition of such duplex atom imparting 
 a gradation of physical properties, corresponding with the 
 progressive ratio of duplication ; as is shown in the suc- 
 cessive increase in density, and in the elevation of the boil- 
 ing point. 
 
 These basic hydrocarbons, each of which is a distinct 
 compound, severally enter into union with a typal com- 
 pound of the same elements in different proportions. For 
 instance, with HC 2 , an electro-negative substance, analo- 
 gous to sulphur, phosphorus, and arsenic, and capable, like 
 these, of forming acids by combining with oxygen : thus, 
 H 2 C 2 + HC 2 = H 3 C 4 ; and again, H 3 C 4 + O 3 = H 3 C 4 O 3 , 
 and all their respective homologues only differ from each 
 
 N 
 
178 CHEMICAL ELEMENTS, DUALISMS 
 
 other according to the number of duplications of the basic 
 hydrocarbon ; the typal constituent remaining unaltered. 
 
 Again, we have the same hydrocarbons uniting with 
 another distinct and characteristic compound of hydrogen 
 and carbon, as H 3 C 2 , in which the basic hydrogen is in 
 the ascendant; forming a corresponding electro- positive 
 quasi-element, which is analogous to the alkaline and 
 basic metals, combining also with oxygen to form oxides, 
 which, united with acids, become salts : thus, H 2 C 2 + H 3 C 2 
 = H 5 C 4 , and H 5 C 4 + O = H 5 C 4 O ; lastly, H 5 C 4 O + HO 
 = H 6 C 4 2 . So that if these three quasi* elements HC 2 , 
 H 2 C 2 , H 3 C 2 , were severally distinguished by a special 
 name and symbol, (as in the case of cyanogen, Cy,) all 
 the multiplied homologues of the ethers, hydrocarbons, and 
 fatty acids, might be more simply expressed : which would 
 greatly facilitate the labours of the student in the acquisi- 
 tion of this complicated branch of the science. 
 
 In order to simplify our statement as much as possible, 
 we did not allude to the fact that the electro-negative and 
 the electro-positive constituents are also capable of dupli- 
 cation in the same manner as the neutral hydrocarbons ; 
 we cannot, however, enter into details, but must rest 
 content with pointing out, that the same discriminating 
 notation for the higher powers of each substance will be 
 found generally applicable. 
 
 It has already been noticed that substances vary in 
 their electrical relations to those substances above and 
 below them in the scale ; so that the same substance may 
 occupy a basic or typal position in compounds, according 
 to the character of the substance with which it is united. 
 Thus nitrogen is capable of combining with the more 
 
OF PHYSICAL AND SPECIFIC POWERS. 179 
 
 typalor electro-negative substance, oxygen ; and also with 
 the more basic or electro-positive substance, hydrogen; 
 forming in each case a series of compounds which differ 
 in properties according to the degree of preponderance of 
 the associated element. In the one case the series is NO, 
 NO 2 , NO 3 , NO 4 , NO 5 ; and in the other the series is 
 HN, H 2 N, H 3 N, H 4 N: three members of the latter 
 series are as yet unknown as insulated substances, ammo- 
 nia, H 3 N, being the only one with which we are actually 
 acquainted ; but the analogy of the carbon series, C 2 , a 
 substance very analogous to N in its combining relations, 
 renders it not improbable that this hypothetical series 
 may be ultimately substantiated. The analogous series 
 of duplex carbon, C 2 , is as follows: HC 2 , H 2 C 2 , H 3 C 2 , 
 H 4 C 2 . The characteristics of different parts of these 
 series are deserving of particular attention. The beginning 
 of each series is negative in respect to the latter part, 
 which becomes eminently positive; and it is curious that 
 not only in these, but also in the oxygen series, the odd 
 numbers are distinguished by possessing the strongest 
 marked properties : this is a curious circumstance, but one 
 which accords well with the principle of our system, viz. 
 that equal forces neutralise each other, so that their 
 special attributes do not appear in the compound ; whilst 
 unequal forces, when combined, manifest the characteristic 
 of the predominant or plus constituent. 
 
 The usual notation of compound substances may in the 
 more simple cases be easily interpreted ; but in very com- 
 plicated cases it is a difficult task to reduce this empirical 
 expression into a rational formula. And this circumstance 
 alone shows the necessity of adopting some simple expres- 
 
 N 2 
 
180 CHEMICAL ELEMENTS, DUALISMS 
 
 sion for each distinct class of complex substances ; such as 
 we already have, with great advantage, for cyanogen, Cy : 
 which, however, compared to the substances alluded to, 
 has a very simple composition, C 2 N. 
 
 If the binary constitution of compounds, according to 
 the formula A + B = AB, were adopted ; it would, we 
 think, greatly facilitate the attainment of a more satisfac- 
 tory notation : in our introduction, it was pointed out how 
 the basic and typal plus condition, in different compounds 
 of the same substances, might be indicated ; this in many, 
 more particularly physical, cases might be advantageous ; 
 but it is not required in chemistry, for in its compounds, 
 whether simple or complex, the position of the symbol in 
 the notation marks whether it be basic or typal, and the 
 numerals affixed to either constituent clearly shows which 
 is in the ascendant. In addition to these guides, the 
 knowledge that the atoms of elements may be frequently 
 duplicated, so as to act in the compound as single atoms 
 (and capable as such of being transferred into various com- 
 binations), may ultimately lead to the establishment of a 
 more simple and a better system than now prevails. But 
 this cannot well be the work of an individual : it should 
 be performed by the concurrence of several chemists, in 
 order to give it due authority. 
 
 This discussion, however, is drawing us beyond our 
 limits ; we will, therefore, conclude with remarking, that 
 chemical forces, in every compound, must necessarily be 
 antagonistic: even when the constituents are very similar, 
 as in alloys, combinations of oxides, and even of different 
 oxides of the same metal ; for as there is, in all these cases, 
 action and reaction, there must be antagonism, though of 
 
OF PHYSICAL AND SPECIFIC POWERS. 181 
 
 such a feeble character as to give no well-marked indica- 
 tions thereof. And, that in chemical actions, we have the 
 broad and well-defined distinction which separates them 
 from physical actions, that the opposite forces by which 
 they are accomplished may be exhibited in a distinct state 
 of individual existence : so that their characteristics may 
 be carefully examined and determined ; not inferentially, 
 as in the case of antagonistic physical forces, but by actual 
 observation and investigation. 
 
 In conclusion, then, it may be observed that chemical 
 substances are objects of chemical science. The arrange- 
 ment of these objects forms the preliminary step or natural 
 history branch of chemistry ; and this accomplished, the 
 consideration of the specific forces, whether simple or 
 compound, which make up the constitution of these objects, 
 and the determination of their modus operandi when they act 
 and react on each other in the production of chemical phe- 
 nomena, bring us acquainted with the dynamical or causal 
 branch of the science. And when the science is completed 
 by the application of both the logical methods of induction 
 and deduction ; then, by a knowledge of the rational laws 
 by which these forces are directed, we should be able to 
 determine the nature of a compound before it has been 
 experimentally demonstrated : a result which has already 
 been actually attained in the case of the combinations of 
 many hydrocarbons ; for not only the equivalent numbers 
 of their constituents were foreknown, but the prevision 
 was carried to the extent of determining the specific gravi- 
 ties and boiling points of unknown liquids. 
 
182 
 
 CHAP. VII. 
 
 ORGANISMS, DUALISMS OF CHEMICAL AND VITAL 
 POWERS. 
 
 Life or Vital Principle the efficient Cause of Organic Phenomena. 
 Opinions concerning this Force. The most recent that of Dr. 
 Carpenter. This Opinion evades one Difficulty by creating another 
 equally insoluble. All Forces said to be one and the same, 
 mutually convertible. Life is transformed Heat. The specialty 
 of the material Substratum alone determines the Character of the 
 Force. Whence then this Specialty? The organic Germ is 
 itself a living Organism ; Heat cherishes Life, but does not impart 
 it. Difference between chemical and organic Dualisms. The Re- 
 lation of specific Vital Forces to universal Physical Forces. 
 Death, the Dissolution of the Organic Dualism. Life not the im- 
 mediate Producer of Motion It makes Physical Forces sub- 
 servient to this Purpose. Life is a directing, superintending 
 Energy. It functions in acquiring, appropriating, and utilising 
 other Forces, both physical and chemical. Dr. Carus on the Nature 
 of Life. Vital Force a final Cause: so in a sense are all other 
 Forces. The Development of Organisms. The vegetative Func- 
 tions of animated Creatures Reducible to simple Principles. 
 Vegetables the intermediate Link between Minerals and Animals. 
 Animals distinguished by the Attribute of Sensibility. The 
 Nervous and Muscular Systems of Animals. Instinct and Know- 
 ledge. On the Transmutation of Species. Conclusion. 
 
 THE physiological researches of the present day all tend 
 to the conclusion, that orga ic phenomena cannot be fully 
 explained, either on chemical or physical principles; for 
 
THE NATURE OF VITAL POWERS. 183 
 
 largely as these principles enter into the consideration of 
 such phenomena, yet after the elimination of all relating 
 thereto, there are many outstanding facts, neither few nor 
 unimportant, that must be referred to some other principle. 
 Call this special influence, which directs the functions of 
 organisms, Life, Vital Principle, Vitality, or what you 
 will ; still the fact of its existence, though it has often 
 been ignored, is now acknowledged by the highest 
 authorities. 
 
 Concerning the precise nature of this vital force, how- 
 ever, there has been, and still is, a great diversity of 
 opinions; but we will restrict ourselves to those which 
 are now most prevalent. Some suppose that each kind of 
 creature, whether vegetable or animal, has a specific prin- 
 ciple of vitality, which it has derived from its parents, and 
 which in some mysterious manner is transmitted from ge- 
 neration to generation ; so that each individual is a portion 
 of the common stock of vitality belonging to its own species. 
 According to this view, the germ-cell, in which each in- 
 dividual originates, is the production of its parents ; and 
 however minute it may be, it is potentially adequate to 
 the development of the future creature, whether it be an 
 animalcule, or the largest of animals. 
 
 This hypothesis, in the opinion of other physiologists, 
 is irrational. They admit that the germ-cell is an animated 
 organism, but they cannot conceive that its minute vital 
 force is capable of producing the mature creature ; and to 
 meet this difficulty, they suppose that the materials which 
 are incorporated into the living structure, by nutrition, 
 contain vital force in a dormant state, which is evoked 
 into activity by becoming organised. So that as the 
 
 N 4 
 
184 ORGANISMS^ DUALISMS OF 
 
 creature grows, it acquires, pari passu, an increased 
 amount of vitality, equivalent to its enlarged functions. 
 
 And lastly, according to Dr. Carpenter*, "the vital 
 force which causes the primordial cell of the germ first to 
 multiply itself, and then to develope itself into a complex 
 and extensive organism, was not originally locked up in 
 that single cell, nor was it latent in the materials which 
 are progressively assimilated by itself and its descendants ; 
 but is directly and immediately supplied by heat, which is 
 constantly operating upon it; and which is transformed 
 into vital force, by its passage through the organised fabric 
 that manifests it." But afterwards he affirms that he " no 
 more regards heat as the vital principle, or as itself identi- 
 cal with the vital force, than that it is identical with 
 electricity, or with chemical affinity; nor does he in the 
 least recognise the possibility that any action of heat upon 
 inorganic elements can of itself develope an organised 
 structure of even the simplest kind. The pre-existence of 
 a living organism, through which alone can heat be con- 
 verted into vital force, is as necessary upon this theory, 
 as it is upon any of those currently received amongst 
 physiologists ; and it is the specially of the material sub- 
 stratum, thus furnishing the medium or instrument of the 
 metamorphosis, which in his opinion establishes, and must 
 ever maintain, a well-marked boundary between the 
 physical and the vital forces. Starting with the abstract 
 notion of force, as emanating at once from the Divine Will, 
 we might say that this force, operating through inorganic 
 matter, manifests itself as electricity, magnetism, light, heat, 
 
 * Philosophical Transactions, 1850, p. 752. 
 
CHEMICAL AND VITAL TOWERS. 185 
 
 chemical affinity, and mechanical motion ; but that when 
 directed through organised structures, it effects the ope- 
 rations of growth, development, chemico-vital transforma- 
 tions, and the like ; and is farther metamorphosed through 
 the instrumentality of the structures, thus generated, into 
 nervous agency and muscular power. If we only knew 
 heat as it acts upon the organised creation, the peculiarities 
 of its operations upon inorganic matter would seem as 
 strange to the physiologist, as the effects here attributed to 
 it may appear to those who are only accustomed to con- 
 template the physical phenomena to which it gives rise. 
 The variety of organic forms called forth by the agency of 
 heat, which may be regarded as the products of its opera- 
 tion upon living germs, does not present any real obstacle 
 to the reception of this doctrine ; since in any hypothesis, 
 which assumes a common force as operative in the living 
 kingdoms of nature, it is necessary to admit that this force 
 is modified in its actions by the properties of the germ ; 
 just as that the general force of chemical affinity manifests 
 itself differently in the reactions of each elementary and 
 composite substance." 
 
 This doctrine of Dr. Carpenter concerning the nature of 
 vital force, is a legitimate corollary of the principle, now 
 so generally accepted, that natural forces are mutually con- 
 vertible ; and we have quoted it at some length, because 
 it is clearly and intelligibly expressed, and will enable 
 us the better to set forth our views concerning vital force, 
 by contrasting them together. 
 
 It has been more than once stated, that one universal 
 force can be no other than an absolute ; and being thus 
 placed out of all relations, it cannot come within the limits 
 
186 ORGANISMS, DUALISMS OF 
 
 of human knowledge ; consequently there must be a 
 dualism of forces, in order to render action and reaction 
 possible, which are the requisites of all phenomena. Now 
 Dr. Carpenter in some measure provides for this objection, 
 since he regards such a force as emanating directly from 
 the Divine Will ; and as operating through inorganic 
 matter, and through organised structures, assuming there- 
 by the different aspects of physical, chemical, and vital 
 forces. Such a conception may be formed ; but even ad- 
 mitting its probability, it leaves our knowledge equally 
 imperfect ; it only strives to evade one difficulty by start- 
 ing another, leaving us as far as ever from an explanation 
 of the nature of living organisms. It calls in the aid of 
 various pre-existing substrata, as the necessary media for 
 the differentiation of Divine force ; but what we want to 
 know, is the inner nature or essence of matter, of chemical 
 elements, and of organic germs : have they not also pro- 
 ceeded from the Divine Will ? and whence comes it to pass 
 that they can impart to one and the same force such 
 varied aspects ? An organism is throughout its whole ex- 
 istence a living body, a body actuated by a vital force or 
 life ; the basis or substratum of such an organism is a struc- 
 ture consisting of chemical substances, which serves as a re- 
 sisting force, or point d'appui, in concurrence with which the 
 vital force acts ; and thus results that action and reaction 
 which functions as a living creature. In short, an organism, 
 like all other natural bodies, is a dualism of forces, which 
 are co-existent and opposite ; and if such a dualism be in- 
 vaded by an extraneous force, as heat, such a force may 
 modify vital actions, but the changes produced can only 
 be physical. Heat then is not the cause of vital force, for 
 
CHEMICAL AND VITAL POWERS. 187 
 
 the organism possesses it already : it is, however, a very able 
 coadjutor, for it facilitates another, and a lower order of 
 actions, the chemical ; by which inorganic materials are 
 assimilated and rendered fit for the growth of its organic 
 body, by the appropriating and constructing influence of 
 the vital force. When the organism dies, that is, when 
 life departs from the material body, heat does not vivify, 
 nor can it form organic compounds ; but it only hastens 
 chemical actions, by which the constituents of the organism 
 are returned to the chemical kingdom of nature, from which 
 they were derived. 
 
 Organisms, therefore, possess vitality as a necessary part 
 of their constitution ; for when deprived thereof, they are 
 no longer organisms, but only organic remains. It is 
 true, that this vitality can only become efficient under 
 certain conditions, and if these be awanting, it remains 
 dormant as In the case of eggs ; and still more remarkably 
 in the seeds of plants, which after lying deeply buried in 
 the soil for ages, have vegetated when brought near the 
 surface. 
 
 It remains, therefore, still to inquire, What is the nature 
 of this vital force or principle of vitality ? Dr. Carpenter 
 is quite correct in the parallel which he draws between 
 organisms and chemical elements ; for they are analogous 
 dualisms, consisting of material bodies, actuated by specific 
 forces ; and both are the objects of special sciences : but 
 we do not agree concerning the nature of chemical forces ; 
 we believe that they are actual specific powers, indepen- 
 dent existences, as set forth in the last chapter; whilst he 
 regards them as one and the same force, modified by the 
 peculiar substance of the individual elements. So on his 
 
188 ORGANISMS^ DUALISMS OF 
 
 view, instead of many specific forces, we have an equal 
 number of different substances, substrata, which variously 
 affect the unknown universal force which emanates from 
 the Divine Will. Now if we accept the common notion 
 concerning matter, that it is some unknown substratum in 
 which properties, and consequently chemical properties, 
 inhere, we still require to know the cause of the difference 
 which characterises the respective chemical elements ; which 
 makes them to variously differ from each other, and from 
 the matter with which they are conjoined. This difference 
 of properties cannot be ignored ; it must necessarily be 
 referred to the effects of various causes, which as energies, 
 influences, forces, or whatever you may choose to call 
 them, must each of them enjoy its peculiar attribute, which 
 is manifested as a particular property. An element then 
 is matter possessing some peculiar property which is che- 
 mical ; consequently the element is a chemical substance ; 
 and it is therefore superfluous to seek for the extraneous 
 origin of that which already exists in the body itself, and 
 which constitutes its essential individuality. 
 
 The prevalent opinion concerning the oneness and uni- 
 versality of force is indeed very fascinating in its apparent 
 simplicity ; but it is in truth very, complicated and indefi- 
 nite when subjected to a searching investigation. How 
 beautifully simple is the doctrine, in its enunciation, that 
 all natural forces are fundamentally one and the self-same 
 force, the omnipotence of Deity ; and that, therefore, how- 
 ever varied these forces are in appearance, they are all 
 mutually convertible : but when we attempt to apply this 
 doctrine, we are met by the complication, that this uni- 
 versal force can only be manifested under different aspects, 
 
CHEMICAL AND VITAL POWERS. 189 
 
 through the medium of peculiar substrata. Now these 
 substrata, and the changes they undergo, are the pheno- 
 mena which we are contemplating ; we are ^striving to 
 ascertain what these things are in themselves, what those 
 forces are which they evidently possess, for without such 
 they could not act and react on each other, in the produc- 
 tion of phenomena : for every effect must have its cause. 
 When these substrata are chemical and organic substances, 
 we distinguish their peculiar forces as chemical and vital : 
 and to say that such forces are only modifications of a 
 general force, when in relation to such substances, is no 
 explanation at all ; it is a mere evasion of the question, 
 which is, What is it that originally made these bodies che- 
 mical and organic ? or in other words, What are the causes 
 of their peculiar attributes ? 
 
 What forces are ultimately, in themselves, we know 
 not, it is beyond the scope of human knowledge ; for all 
 our knowledge is relative, and we can only know forces 
 by their effects : so far we may attain to an explanation of 
 the constitution of natural bodies ; and the doctrine which 
 we are advocating seems to explain, but perhaps not satis- 
 factorily, the nature of organisms, when it defines them 
 as " chemical bodies actuated by specific vital powers." 
 
 In the organic dualism of powers, there is a marked 
 difference which distinguishes them from the chemical 
 dualisms. In the latter the body or basic power of the 
 dualism is material or physical ; and hence it is that che- 
 mical substances, besides their specific, also possess physi- 
 cal properties : in the organic dualism, the body is chemical; 
 that is, a compound of physical and chemical powers, a 
 complication of forces manifesting corresponding pheno- 
 
100 ORGANISMS, DUALISMS OF 
 
 m3na, and exerting a powerful antagonism against the 
 specific force or vital power, by which however they are 
 constrained and subordinated, according to its innate 
 directing reason, which is its rational law of action. There 
 is also another and a grand distinction between chemical 
 and organic dualisms : the union of the constituent powers 
 of the former is indissoluble ; but in the latter case, the 
 powers may be disjoined, the specific force departing, we 
 know not whither, as a matter of natural knowledge ; 
 whilst the body remains, as an aggregate of chemical 
 bodies, which follow the laws of their order. We are 
 prepared to understand, in some measure, by the circum- 
 stance of the complication of nicely balanced forces, the 
 separation which occurs on the dissolution of organisms ; 
 still it has the appearance of a departure from that pro- 
 gress toward perfection, which marks the different condi- 
 tions of creatures in the ascending scale of nature : it 
 is a perplexing thought, that whilst chemical elements are 
 permanent and imperishable during the course of nature, 
 that the higher order of beings, organisms, should only 
 enjoy a limited existence ; and that then " the place which 
 knew them, should know them no more." It is a mystery ; 
 but whilst we contemplate it, the attention is arrested by 
 a diversity in the capacity of organisms, which operates 
 as a partial compensation in their favour : they have the 
 peculiar faculty of propagating their species,, by which 
 provision the permanence of their kindred is established ; 
 so that whilst the individuals themselves die, they ever 
 live in their descendants ; an arrangement which seems to 
 accord with the conservation of forces, so conspicuous in 
 the other departments of nature. 
 
CHEMICAL AND VITAL POWERS. 191 
 
 On a former occasion it was stated that chemical powers 
 arc related to universal attraction, as species are to their 
 genus ; that these specific forces all partake of an attracting 
 and condensing tendency, but that as species they also 
 possess the differential characters of peculiar elective and 
 combining properties. And in like manner, a relationship 
 may be discerned between vital powers and universal 
 repulsion ; as specific forces, they have the generic cha- 
 racter of repulsion, a similar instability, and given to 
 incessant changes, tending to a continual outward ex- 
 pansion in growth and multiplication. Thus by these 
 specific relations of chemical and organic powers to the 
 universal physical powers, we conceive that it is possible 
 to establish a System of Nature : the dualism of powers, 
 attraction and repulsion, forms the universal basis, the 
 summum genus of all material bodies ; which is diversified 
 on the side of attraction by specific chemical powers, and 
 on that of repulsion by specific vital powers. 
 
 Life then, on this view, is the continued union of the 
 constituent forces of the organism ; death is the dissolution 
 of this union. Life has been likened to the flame of a 
 lamp, which is sustained as long as nourishment is supplied 
 to the wick ; and the communication of flame to other 
 lamps, without any diminution of its energy, has been 
 adduced as no unapt illustration of generation : could the 
 flame renovate its own organism, that is, the lamp with 
 its combustible contents, and also produce other lamps of 
 the same kind, the analogy would hold good : as it is, 
 however, the simile does not assist our knowledge. 
 
 In contemplating the growth of the higher orders of 
 organisms, whether vegetable or animal, from the earliest 
 
192 ORGANISMS, DUALISMS OF 
 
 stage of its existence as a primordial cell to its state of 
 maturity, the circumstance that most rivets the attention 
 is the gradual development of its structure, accompanied 
 by a corresponding increase of its vital energies. And so 
 on a general survey of animated nature, we find evidence 
 of a similar order of progression throughout the whole 
 system ; broken, indeed, into subordinate groups, as if the 
 process were being tried over and over again on different 
 types, but still sooner or later resuming its onward course 
 towards perfection. Thus each organic function seems to 
 be ever tending toward a higher development, not only 
 in the several stages of each individual organism, but in 
 creatures of different kinds, as they rise one above the 
 other in the scale of nature ; and this not only obtains in 
 the functions of growth and reproduction which are common 
 to all organisms, but also in those of muscular movements 
 and nervous sensibility, and even in those of the instinctive 
 and intellectual faculties. In every creature, however, 
 varied as its functions may be, these do not result from 
 the operation of as many distinct and independent in- 
 fluences or faculties, for each creature has only one specific 
 principle of activity ; and however varied and elevated its 
 actions may be, these only denote the peculiar attributes 
 of its specific power, and mark its degree in the systematic 
 arrangement or hierarchy of natural powers. 
 
 In attempting to comprehend the nature of vital force, 
 (which may in the same individual, as in the highest de- 
 veloped organism, man, produce such diversified operations,) 
 it is requisite to divest ourselves of the ordinary notion 
 concerning force. What we understand by force, is any in- 
 fluence which is efficient in producing some kind of change; 
 
CHEMICAL AND VITAL TOWERS. 193 
 
 but the more common notion concerning force is that 
 which gives dynamical impulse to bodies, imparting some 
 kind of motion, and called accordingly physical force. 
 Many of the changes which organisms undergo are purely 
 physical, variously modified by their peculiar structures ; 
 but all subordinated to the vital principle : thus, various 
 capillary attractions and osmotic diffusions, also muscular 
 and nervous motions, are mechanically performed according 
 to physical laws : and yet are so directed, in subjection 
 to the creature's vital principle, as to operate in opposition 
 to the law of gravity. In short, vital force is not a prin- 
 ciple, whose effects can be weighed and measured; though 
 it is associated with a material body as its correlative 
 power, which possesses physical properties: but it is a 
 self-directing and superintending principle, which controls 
 the physical and chemical forces of its body, turning them 
 to account for its own purposes; thereby working out and 
 performing the functions of its body, according to pre- 
 determined intelligent designs. It is not, therefore, sur- 
 prising, that a force which can act with such authority 
 should be capable of developing a body of even considerable 
 magnitude from a microscopic germ-cell: its successively 
 increasing size and strength do not immediately depend on 
 the continual accession of energy by the conversion of 
 physical force into its own essence ; but by its domination 
 over accumulated material forces, whose efficiencies are 
 made subservient to its enlarged requirements. An or- 
 ganism is a dualism of powers, which function by their 
 mutual action and reaction ; and under this joint influence 
 it acquires, appropriates) and utilises such substances as 
 
 o 
 
194 ORGANISMS, DUALISMS OF 
 
 are fit for its purposes, and fall within the limits of its 
 operations. 
 
 Dr. Carus *, in his " Essay on the Kingdoms of Nature, 
 their Life and Affinity," after recounting the several pro- 
 cesses in the development of a perfect plant from its seed, 
 remarks, " Thus closes the circle of its being, in that form 
 out of which it first issued. Throughout this chain of 
 phenomena, we find a certain determinate succession, a 
 regularity which compels us to refer these movements to 
 the operations of one internal and universal principle, in 
 which all the others are comprehended. It is evident 
 that this internal, this essential and efficient principle, can 
 be no single thing, such as the body of the plant, the 
 chemical change of its substance, or the circulation of its 
 sap, and still less the effect of external influences, but 
 rather all these together ; a something in which all these 
 inhere as their common cause, and which we characterise 
 as a unity by the generic appellation, life. Hence it is 
 easy to perceive how erroneous it would be to suppose 
 the plant first organised, and life added to it as an attri- 
 bute, and consequently as something extrinsic. On the 
 contrary, life is necessarily the original principle, and the 
 body one of its particular phenomena ; conceived, therefore, 
 not as permanent, but as perpetually changing : and this 
 idea of it is conveyed in the term formation, inasmuch as 
 it signifies a thing not only formed, but forming itself." 
 This view of Dr. Carus is in some respects similar, though 
 not precisely the same as ours. According to our view, 
 an animated being is twofold in its constitution, but es- 
 
 * Taylor's Scientific Memoirs, vol. i. p. 224. 
 
CHEMICAL AND VITAL POWERS. 195 
 
 sentially one in its compound individuality : as long as 
 this union is maintained, the creature lives or has life; 
 the action and reaction of its constituent forces being 
 manifested as the phenomena of life. During life, the 
 chemical and physical forces, of which the organic body 
 consists, are variously affected by the condition of the 
 medium in which they are placed ; and also by the 
 controlling influence of its vital force, which may be 
 variously distributed throughout the system, energising 
 one part more than another, and yet, however unequally 
 diffused, being ever one and the self-same individual 
 power. 
 
 From what has been stated, it is evident that we not 
 only maintain the existence of specific vital powers, which, 
 like the specific chemical powers, form and energise their 
 own bodies according to definite designs ; but also, that 
 these powers are final causes, varying their modes of 
 action according to circumstances, so as to accomplish 
 predetermined purposes. We must, therefore, dwell 
 awhile on this subject, and give our reasons for accepting 
 the notion of final causes, which'is at present in great dis- 
 credit. And by way of introduction, we will quote a 
 passage from Dr. Roget's Physiology*, not a very recent 
 authority, but one which, we think, still expresses the 
 current ideas thereon. " However natural it may be to 
 conceive the existence of a single and presiding principle 
 of vitality, we should recollect that this, in the present 
 state of our knowledge, is only a fiction of the mind, not 
 warranted by the phenomena themselves, in which we 
 
 * Encyclopaedia Britannica, 1842. 
 
 O 2 
 
196 ORGANISMS, DUALISMS OF 
 
 perceive no such diversity ; and therefore inadmissible, as 
 the result of a philosophical induction. We find that 
 vitality ceases in different textures, at different periods 
 prior to the total extinction of life ; a phenomenon which 
 appears scarcely compatible with the unity of any such 
 power. Attempts have been made to reduce the 
 phenomena of the inorganic world to a single primordial 
 law ; and they possibly may prove successful : but no 
 such approximation can yet be attempted, with any pros- 
 pect of success, between the muscular, the nervous, the 
 sensational and the organic powers ; nor can we establish 
 any kind of association between them, but by the consider- 
 ation of another, and a totally different class of relations, 
 namely, those they bear to the general object which they 
 combine to produce. This, however, is to substitute j^woZ 
 for physical causes, which are the only legitimate objects 
 of philosophical analysis, and the true basis of the physical 
 sciences." 
 
 It is true that some textures of the body retain signs of 
 vitality longer than others, after the creature's death, 
 which may seem inconsistent with the unity of vital 
 power; but it must be remembered, that though the 
 vitality of each creature is indeed one, yet it pervades all 
 parts of the system, but in different degrees of intensity ; 
 and it does not follow, that if the centre and source of this 
 energy be destroyed, that all the parts of the system should 
 simultaneously collapse, as in the discharge of accumulated 
 force in an electrified body. It rather resembles the force 
 by which machinery is propelled, the parts of which do not 
 immediately come to a state of rest when the moving 
 power is detached, but they continue to move by their 
 
CHEMICAL AND VITAL POWERS. 197 
 
 vis inertia until restored to their original condition. The 
 universal convertibility of physical forces was not an ac- 
 cepted doctrine when Dr. Koget hesitated to receive it as 
 " a primordial law ; " but since then, speculative ingenuity 
 has boldly attributed all description of organic powers " to 
 a single physical power." We have already expressed our 
 dissent to this doctrine, and endeavoured to demonstrate 
 that there can be no such thing as a simple physical power ; 
 all natural bodies being dualisms of powers. When we 
 maintain that vital forces are final causes, it is evident that 
 the same holds good with all other forces, since we make no 
 distinction, in this respect, between vital and physical 
 causes. We are therefore ready to abandon the term 
 final altogether, as being, according to our views, super- 
 fluous ; for all forces are regarded by us as reason-directed 
 powers, which only act according to rational laws. In 
 every regular series of phenomena, however extensive, the 
 plus state or energy of any body in the series is a cause 
 of the effect which is manifested in the succeeding phe- 
 nomenon; and this physical energy is some particular 
 force, which in its action is regulated by its innate law, 
 its rational guide, which determines its operation accord- 
 ing to a definite design. So that all causes are, in truth, 
 final causes, whether physical, chemical, or vital : the 
 physical and chemical are said to act necessarily, because 
 under precisely the same conditions they always produce 
 the same effects ; whilst the vital have in some of their 
 operations a choice ; but as this choice is always exercised 
 with the intention of accomplishing some given purpose, 
 the vital must be final causes, be they good or bad, wise 
 or unwise. 
 
 o 3 
 
I r 8 ORGANISMS, DUALISMS OF 
 
 It is no new idea, that the principle of life, the anima, 
 is a directing, superintending influence, regulating the 
 functions of its body according to a rational design. Even 
 Dr. Carpenter*, whilst advocating the relationship between 
 physical and vital forces by means of a mutual converti- 
 bility, admits that the organism's " assumption of its com- 
 plete and perfect structure is the result of that perfect 
 harmony and balancing of the several forces of growth, 
 multiplication, and transformation, which indicates, in the 
 most distinct and unmistakable manner, the controlling 
 and sustaining action of an intelligent mind, acting in 
 accordance with a determinate plan." We, however, do 
 not suppose that the rational designs that are worked out 
 in the several organisms are immediately effected by the 
 superintending of an intelligent mind. All natural bodies, 
 and of course the powers of which they consist, have ema- 
 nated from Deity ; and, as His works, bear the impress of 
 His intellectual potency : each natural power is not only 
 endowed with a peculiar kind of force, but also with a 
 rational faculty, according to the capacity of which it is 
 able to put forth and exercise this force : that is, a force 
 acts according to its knowledge, be it latent or apparent, 
 instinctive or acquired ; and according to its designs only 
 can it function ; for knowledge and efficiency must have a 
 corresponding relation in every natural power. Doubtless, 
 the origin and continuance of all things must be ultimately 
 ascribed to a First Cause ; but with this we are not con- 
 cerned at present : we are striving to interpret the imme- 
 diate causes of natural phenomena; and must search for 
 
 * Philosophical Transactions, 1850, p. 773. 
 
CHEMICAL AND VITAL POWERS. 199 
 
 them in the things themselves ; otherwise we do not untie, 
 but cut the Gordian knot. 
 
 For these reasons we differ from those who ignore final 
 causes ; or rather we believe that, in a sense, all causes 
 are final : for all natural powers are rational forces, acting 
 as the means to effect certain determinate ends. Desirous 
 that our meaning should not be misunderstood, at the risk 
 of being deemed tedious, we repeat that natural powers 
 are of two distinct kinds. One kind of power acts com- 
 pulsorily, or in a predetermined manner, according to the 
 laws of its inherent, but unconscious, reason ; or of neces- 
 sity, as it is usually termed ; and the resulting phenomena 
 are, under the same conditions, uniform and invariable. The 
 other kind acts not passively and instinctively, but accord- 
 ing to acquired knowledge, that is, consciously ; and has a 
 freedom of choice in its actions, the exercise of this choice 
 being regulated by some intelligent design, whether good 
 or evil. We are justified, therefore, we think, in regarding 
 powers not merely as forces, but as reason-directed forces : 
 for whether they act consciously or unconsciously, they can 
 only do so according either to instinct or to knowledge ; 
 that is, according to reason, which may voluntarily or in- 
 voluntarily superintend the creature's actions. Both these 
 kinds may be conjoined in the same vital power : and 
 since this power is capable of existing in different phases 
 in the same organism, the concurrence of these with the 
 complex material forces, which constitute the resisting 
 power of the dualism, must necessarily produce, by the 
 number of forces which come into play, an almost infinite 
 variety of vital phenomena. And, that these should often 
 baffle all our attempts at explanation, is not surprising; 
 
 o 4 
 
200 OKGANISMS, DUALISMS OF 
 
 for we know how many intricate variations of the atmo- 
 sphere, which are purely physical, and therefore compara- 
 tively simple, have hitherto remained unsolved. 
 
 There is, however, no occasion to be disheartened at the 
 slow progress that has been made in lifting the veil which 
 conceals the mysteries of life. Our knowledge on this 
 subject is, indeed, as yet indistinct and incoherent: we 
 have a multitude of interesting facts, which is, day by 
 day, increasing; and what is more important, there are 
 very many centres in various departments of the subject, 
 around which there has been great and systematic aggre- 
 gations, which are rapidly tending to a common generali- 
 sation. We must, therefore, strive to realise this union by 
 some happy induction : and though attempt after attempt 
 may fail, we must not desist at the dictates of a " barren 
 caution, but still dare to venture upon the quest of truth." 
 
 One grand generalisation has been accomplished in 
 physiology, which has given a firm basis to our knowledge, 
 a fixed point of departure, by which we may ascend to 
 higher and more intricate departments of the science : we 
 allude to what has been called the organic or vegetative 
 functions of animated bodies. These processes are peculiarly 
 corporeal, but universal : they form the sum total of exis- 
 tence in the vegetable kingdom ; and also make a consider- 
 able but subordinate part of the phenomena exhibited in 
 the animal kingdom. Each kind of these functions mani- 
 fests in different creatures an almost endless variety ; and 
 this circumstance affords one of the most interesting con- 
 siderations in comparative physiology : it enables us to 
 trace in the continuous series of animated beings, as they 
 ascend one above another in the scale of nature, a progres- 
 
CHEMICAL AND VITAL POWERS. 201 
 
 sivc development of each function, and of its correspond- 
 ing organ, until it has from the simplest condition attained 
 to its highest perfection ; an illustration in the whole sys- 
 tem of nature of that unfolding of diversity out of unity, 
 which characterises each individual organism in its gradual 
 growth, from a primordial cell to a state of maturity. If 
 it were not for the continuity of this natural chain of 
 sequences, the great variation of the links when remote 
 from each other would be incomprehensible : but by this 
 systematic development of nature, we are able to grapple 
 successfully with the complicated subject of organic func- 
 tions. 
 
 A knowledge, however, of their individual characters, 
 and of the order of their relations toward each other, 
 only constitutes the introductory or natural history part 
 of this department of physiology : there remains for con- 
 sideration the causal or dynamical part of the science, by 
 which we learn the nature of the forces concerned in 
 these functions, and the laws which regulate their actions. 
 This topic has been already in a great measure antici- 
 pated. The organism consists of a material body, a com- 
 pound of physical and chemical forces, and of a specific 
 vital force, which controls and directs the actions of its 
 body, according to its own peculiar rational design. The 
 ultimate composition of the bodies of all organisms is very 
 similar, the essential elements being very few in number ; 
 but these are associated together in such varied proportions, 
 both mechanically and chemically, that the resulting struc- 
 tures are exceedingly diversified in appearance. All these 
 diversities depend on the peculiarities of the presiding 
 vital power : but multitudinous as these specific powers 
 
202 ORGANISMS, DUALISMS OF 
 
 are, there are certain methods of operating which are 
 common to them all, and which are so few in number as 
 greatly to simplify the comprehension of the subject. 
 Each and all of the vital powers have the faculties of 
 acquisition, appropriation, and utilisation; and in the exer- 
 cise of these faculties, however varied the means employed, 
 and the circumstances under which they operate, the 
 organism acquires additional materials, or food, from the 
 medium in which it is placed : then it appropriates this 
 food by a process of assimilation, distributing and arrang- 
 ing it either for the growth, or farther development, of 
 its structure ; and lastly, it utilises the organs thus formed, 
 by causing them to perform their respective functions. 
 
 Now during the actions and reactions which take place 
 during organic functions, though they partake one while 
 of a physical, and at another time of chemical characters, 
 must not be regarded as wholly appertaining to the material 
 body of the respective organism ; but to this, in concur- 
 rence with vital power. It is true that after a creature is 
 dead, many peculiar physical and chemical changes may 
 take place' that are decidedly organic ; but they have 
 been effected in consequence of the material medium 
 having a particular structure, which was derived from the 
 operation of vital power : such media may have for awhile 
 peculiar influences, but unless renovated they cannot en 
 dure ; and such renovation can only take place in a living 
 body. In truth, all the physical influences exerted on an 
 organism from without, and all those changes within, re- 
 lating to weights and volumes and motions of any kind, 
 are purely material, that is, physical and chemical : but 
 they are all modified by the peculiar structures of organ- 
 
CHEMICAL AND VITAL TOWERS. 203 
 
 isms; and these peculiarities depend upon the arrange- 
 ment of materials which is effected by vital power : and 
 thus it is that the physical and chemical powers become 
 subjected to the vital. Osmotic and capillary actions are 
 very conspicuous in organic functions; they are indeed 
 effected by physical forces, but you will look in vain for 
 precisely the same actions in the inanimate world: we 
 therefore contend, that if these phenomena require special 
 media for their manifestation, the forces concerned in the 
 production of these media are indirectly the causes of their 
 occurrence. Just as man can externalise his operations, 
 so as to produce outside his body a machine fashioned of 
 material, that is of physical substances, and can actuate it 
 by physical forces, so as to produce various works of art : 
 no one would hesitate to assert that man is the artist, and 
 not the physical forces; for they can only thus operate 
 through the medium of a peculiar arrangement, in which 
 they had no immediate concern. 
 
 In the first stage of organic functions, the body of the 
 organism acts physically in the acquisition of food, during 
 which process the vital force is either passive, as in plants, 
 or it is active in directing the performance of higher func- 
 tions in procuring this food, and conveying it into a posi- 
 tion, where, like in the case of plants, it may be physi- 
 cally absorbed or acquired. This accomplished, chemical 
 changes, the process of appropriation, commence ; changes, 
 which for the most part, like those of the physical, can only 
 take place in an organic medium ; and so far only in con- 
 currence with the operation of vital powers ; and assimila- 
 tion being performed, and distribution having been physi- 
 cally made according to the respective structures of the 
 
204 ORGANISMS, DUALISMS OF 
 
 organism, then the controlling influence of vital power, 
 acting according to a rational design, repairs and fashions 
 the various organs for the continuance of their functions ; 
 and the cycle of its operations is completed when the 
 utilisation of its corporeal forces is effected. 
 
 Such is organic life on the lowest or simplest platform 
 of existence, a universal phase of vital powers, which may 
 be regarded as their generic attribute ; and in proportion 
 as specific differential properties are added thereto, organ- 
 isms exhibit a corresponding progression in the system, 
 until they culminate in man, who is a very microcosm, 
 monopolising in himself all the leading types of vital 
 powers, which are separately manifested in the distinct 
 orders of existence. 
 
 In the earliest stage of its existence, every kind of 
 organism is exceedingly simple in its structure. A prim- 
 ordial cell, the production of a pre-existing organism, is 
 the visible body which is actuated by an associated and 
 invisible principle of vitality, and it is the dualism of these 
 that constitutes a distinct and independent being. A cell 
 which does not possess such a principle can only live as part 
 and parcel of another organism ; but when vivified it be- 
 comes a new individual of the same species. During the 
 development of such a germ- cell, though it should ulti- 
 mately attain the gigantic stature of an oak, an elephant, 
 or a whale, the animating principle is one and the self-same 
 vital power : by successive divisions, and subsequent 
 growth, the cell may become enormous masses of agglomer- 
 ated cells ; but the same power which superintended their 
 formation, pervades and actuates them all. This notion 
 closely accords with that of Mr. Paget, who under the 
 
CHEMICAL AND VITAL POWERS. 205 
 
 name of germ-force designates the power which each germ 
 possesses to develope itself into the perfection of a 
 specific form ; but, if we mistake not, we so far differ, 
 that his germ -force is a general or common force ; where- 
 as ours is a multitude of specific forces. What is usually 
 called cell-life, is the cycle of changes which cells under- 
 go : this makes up the entire existence of some organisms, 
 whilst it is only concerned in part in the functions of 
 organisms of a higher order. Cells absorb their nourish- 
 ment from the medium in which they are placed by the 
 osmotic action of the cell- walls ; and the contents of the 
 cells are intermingled to promote the function of assimila- 
 tion, by a species of circulation or cyclosis ; a shadowing 
 forth of that more perfect flux and reflux of fluids so dis- 
 tinct and conspicuous in higher organisations. The cellu- 
 lar structure enters more or less largely into the composi- 
 tion of all organisms: indeed it is generally considered 
 that all the varied tissues are derived from successive 
 transformations of cells. Microscopic researches have 
 taught us that, simple and uniform as cells seem to be at 
 the first glance, they are in reality very diversified : that 
 in many organs, there are cells which are purely genera- 
 tive, being only engaged in the production of a different 
 class of cells ; and that it is the latter alone which discharge 
 the special function of the organ, whether that of secretion 
 or of motion ; and the function being discharged, these cells 
 become effete, and are eliminated from the system as in- 
 or^anic materials. 
 
 O 
 
 Now such changes, though for the most part physical and 
 chemical, are not entirely so ; for if the organism dies 
 they cease, and other changes of a different character 
 
206 ORGANISMS, DUALISMS OF 
 
 supervene : so that it is evident that the concurrence of 
 the principle of vitality and of the corporeal forces is 
 necessary for the continuance of organic functions. The 
 vital force not only presides over and directs the formation 
 of peculiar structures, which are instrumental in greatly 
 modifying chemical and physical actions, producing phe- 
 nomena which cannot occur under any other conditions ; 
 but it actually dominates over the corporeal forces, counter- 
 balancing their constant tendency to rest and rigidity by 
 a species of repulsive energy, which imparts to the or- 
 ganism a continuous state of activity, a reiterated cycle of 
 successive processes, so peculiarly characteristic of the 
 vital principle. 
 
 The relation of the antagonistic forces in an organism 
 is, however, so nicely balanced, that it is readily reduced 
 to a state of equilibrium by an alteration of the condition 
 of the medium in which the creature is situated. Tem- 
 perature is the condition which most frequently exercises 
 a modifying influence over the vital functions; and on 
 this account there is a provision of nature, by which 
 many creatures find protection against the interference 
 of the medium by a capacity of evolving internal heat ; 
 and of constructing such coverings for their bodies as are 
 adapted for their native climate, and variable according to 
 the seasons. Indeed it is very probable that in all organ- 
 isms, during the active performance of their functions, 
 heat is simultaneously evolved, and retained long enough 
 by the immediate cellular structure to facilitate the con- 
 tinuance of chemical changes, and to preserve the products 
 in such a state of mobility, as may enable them to perform 
 the requisite transfusions and circulations. When such 
 
CHEMICAL AND VITAL TOWERS. 207 
 
 provisions, on the other hand, are inadequate for the preser- 
 vation of. such a degree of heat as is necessary for the?e 
 functional changes, a condition is produced which increases 
 the attractive antagonism of the corporeal forces ; and in 
 consequence of this preponderance, the vital force becomes 
 passive, and though still feebly acting in its lowest state, 
 as mere cell-life, its more conspicuous functions are sus- 
 pended. Thus on the approach of winter, trees shed 
 their leaves; the lower animals become dormant, and 
 even some of the higher classes hibernate ; in short, all 
 creatures which depend on extraneous heat as an accessory 
 force to counteract the tendency to a state of rest in aid 
 of the vital energy, all such must necessarily succumb for 
 a season, whilst this auxiliary is withheld ; but their vi- 
 tality is not destroyed, but only overborne by adverse 
 circumstances ; and as a compressed gas regains its elas- 
 ticity on the removal of pressure, so they start again into 
 active life with renewed vigour on the return of a more 
 propitious temperature. Not only heat, but moisture, 
 food, and many other things are requisite for the con- 
 tinuance of life, but neither of these, nor all collectively, 
 constitute the vital principle, but are only the conditions 
 necessary for the exercise of its activity : and when such 
 conditions are present, the specific vital power, and the 
 complex corporeal power of the organism, so act and react 
 on each other, as to perform all that is needful for its 
 existence. The corporeal power is almost identical in all 
 beings, variations of the same physical forces and of a 
 very limited number of chemical forces, but the specific 
 vital forces are very numerous and very dissimilar ; and 
 each, therefore, out of the same materials fashions its 
 
208 ORGANISMS, DUALISMS OF 
 
 peculiar structural form, adapting it to its particular order 
 in the system of nature. 
 
 In vegetables, the vital force seems to be very equably 
 diffused throughout the system of each individual ; and 
 complicated and extensive as its particular form may be, 
 its structure consists of but few tissues, which are more or 
 less uniformly prolonged throughout all parts of the body : 
 and the vegetable functions, in like manner, though much 
 diversified in detail, are all reducible to those of growth 
 and propagation. It is this simplicity which makes 
 vegetables the connecting link between the mineral and 
 animal kingdoms : a bond of union which is corroborated 
 by the important fact, that vegetables alone can convert 
 mineral into organic substances; so that the bodies of all 
 animals are derived immediately or mediately from those of 
 vegetables. 
 
 In animals the vital force assumes the additional at- 
 tribute of sensibility, a higher development of self-directive 
 energy than occurs in vegetables: though even in these 
 there are many remarkable instances of irritability, both 
 accidental and periodical, and -of the tendency of parts to 
 move, and even elongate themselves towards places more 
 favourable for ^egetation ; all of which nearly approximate 
 to passive or instinctive sensibility. In animals, however, 
 this characteristic is more clearly defined, though it varies 
 much in degree during its progressive ascent from the 
 protozoa to man ; and, according to its degree, in this 
 respect the specific vital powers evolve corresponding 
 bodies, capable of discharging higher and more complicated 
 behests. Thus in the Acrita there are no special organs 
 of sense or of muscular motion ; and if they are sentient 
 
CHEMICAL AND VITAL POWERS. 209 
 
 to external influences, it must be by a uniform and diffused 
 sensibility, such as may possibly be found to exist in 
 vegetables, which must in this case be regarded as the 
 lowest degree, or zero, of sensation; a vanishing or minimum 
 point of this attribute. In the Nematoneura, the rudi- 
 ments of a nervous and muscular system have been de- 
 monstrated : they evidently possess a general sense of 
 touch, and the faculty of locomotion ; and judging from 
 the eccentricity of their motions they are self-directive, 
 regulating their movements according to circumstances. 
 In the Homogangliata, sensibility is greatly advanced, 
 accompanied by a high state of development of the nervous 
 and muscular systems, more especially of the former, as 
 is shown by a series of double ganglia or brains : they not 
 only enjoy 'a high degree of the locomotive faculty, but 
 also a great degree of freedom, or choice, in the selection of 
 their movements, in consequence of the special senses 
 with which they are endowed; as those of touch and of sight, 
 and in some cases probably those also of hearing, taste, 
 and smell. On this scale of being, the spontaneous actions 
 seem to be all performed intuitively and instinctively ; the 
 impressions on the senses being responded to by a reflex 
 and involuntary action of the nervous centres: their 
 instinct, indeed, is of the highest order, but still there is 
 no indication of their actions being guided by acquired 
 knowledge, as in those animals that are endowed with 
 conciousness. Lastly, in the . Myelencephala or Verte- 
 brata, sensibility attains its highest development; and 
 pari passu the organisation exhibits a corresponding de- 
 gree of perfection : but even in this class, there is great 
 diversity in the capacities of the several senses. All its 
 
 p 
 
210 ORGANISMS, DUALISMS OF 
 
 members are, in some degree, conscious of the impression 
 made on their senses; and this consciousness is knowledge, 
 which differs from instinct, or latent passive knowledge, 
 in that the latter acts necessarily or compulsively in a 
 definite manner; whereas the former is an acquired rule of 
 action, which may be applied or not, as the creature 
 chooses: and hence its liberty. From which it follows 
 that the greater the amount of knowledge which a creature 
 possesses, the greater its degree of freedom; hence the 
 preeminence of man in this respect ; and the reason of his 
 predominance over all other creatures, for knowledge is 
 power : a creature can only act, that is, its specific vital 
 force can only act according to its rational guide, whether 
 this be instinctive or acquired knowledge. Some of the 
 higher orders of the Vertebrata, though brutes, are so 
 intelligent, possessing so much experience, and making 
 such good use of this acquisition, that we cannot refuse 
 to this high development of consciousness the name of 
 mind; it is not indeed a rational mind, it cannot look 
 below the surface of things, and interpret the reason in 
 nature; but it is nevertheless an understanding mind, 
 which knows things intuitively as they appear to be, a 
 common sense, the lower platform or substratum of the 
 human mind. This subject, however, must be reserved 
 for a separate chapter. 
 
 Hitherto we have spoken of sensibility as the highest 
 attribute of vital power, without any particular mention of 
 the muscular and nervous systems, the instruments by 
 which this mode of vital power becomes efficient. In the 
 same manner, as the vital force superintends and directs 
 the fabrication of its organic body, in order to perform its 
 
CHEMICAL AND VITAL POWERS. 211 
 
 special functions ; one, while framing these on one general 
 or common plan in which there is no differentiation of 
 organs for each particular duty ; and at another time, ac- 
 cording to the degree of the specific power, fashioning a 
 peculiar organ, or even combination of organs for each 
 special function ; so the vital forces of the higher grades 
 follow a similar plan in the construction of their bodies : 
 having a higher attribute they must provide the instru- 
 ments for its manifestation, and these instruments must 
 correspond with the rank of the specific power in the 
 system of Nature. If a specific power has a capacity of 
 directing or willing any particular motion, it must be pro- 
 vided with a special apparatus for the performance of its 
 designs : it cannot of itself perform physical actions, such 
 as motion ; but it can frame an organ, a muscle for in- 
 stance, which having certain attachments to fixed points 
 will, when it undergoes contraction, produce motion accord- 
 ing to its mechanism. But this contraction must have an 
 exciting cause ; and hence the necessity of the association 
 of the muscular and nervous systems: the nerves com- 
 municate to the muscles the stimulus required, and when 
 this is imparted, the muscle is excited to act, which it does by 
 contraction. Every time this action takes place, a certain 
 member of the cells in the structure of the muscle undergo 
 an important change ; and are incapable of again perform- 
 ing the same function, and therefore their remains, as dead 
 or useless matter, are removed from the system; this 
 change is doubtless chemical, produced by the influence of 
 the nervous fluid, analogous to that of electricity ; com- 
 bination is a combining condensing force, evolving the 
 opposite physical force which is transmitted by the me- 
 
 p 2 
 
212 ORGANISMS, DUALISMS OF 
 
 chanism, in the form of the motions produced, The nervous 
 fluid seems to be also a phase of physical force evolved 
 during the combining actions in various parts of the 
 organism ; a force which one while is manifested as organic 
 heat, and at another time as nervous influence ; as the 
 latter, it may be greatly diffused and generally operative, 
 or it may be restricted to definite centres, which communi- 
 cate with particular muscles by means of nerves leading 
 to and from these centres. In such centres, there will be 
 a certain intensity of force, which is subject to the direc- 
 tion of the creature's vital power, which acts, either intui- 
 tively, producing the regular and predetermined actions of 
 the natural functions ; or consciously, that is, subject to 
 the individual's choice, whether according to reason or ca- 
 price : in the former case the action takes place through the 
 reflex nerves without the creature's knowledge ; in the 
 latter it proceeds from a higher and more energetic centre, 
 in consequence of the impressions conveyed thereto by 
 nerves of sense having entered into consciousness. 
 
 So that motions are accomplished by the muscles : some 
 of these motions are more or less incessant and entirely 
 removed from the control of the will, and are therefore 
 excited by the reflex action of the nerves ; and some are 
 subject entirely to the will ; whilst others are capable of 
 both voluntary and involuntary action. But in all these 
 cases, the actions are local and partial ; and it is through 
 the instrumentality of the nerves, that the vital force 
 determines these special actions according to the purpose 
 of its designs, whether the creature is conscious of its 
 intentions or passively influenced by its reason-directed 
 force. 
 
CHEMICAL AND VITAL POWERS. 213 
 
 If we have been so fortunate as to have expressed 'our- 
 selves intelligibly (which on such a complicated subject is 
 no easy matter), it will be perceived that our conception 
 of the modus operandi of vital power is twofold. In organic 
 or vegetative functions, it acts according to its rational 
 laws, in the same manner as physical and chemical powers ; 
 and this holds good whether these functions occur either 
 in plants or animals: but in the higher functions of ani- 
 mals, which are under the influence of the nervous sys- 
 tem, the vital force has two modes of action ; one similar 
 to that of the vegetative, and the other not so bound 
 down to a given course of action ; for having a knowledge 
 or consciousness of several modes it is capable of selecting 
 between them, or in other words, it has a freedom of choice. 
 These different modes are fundamentally one and the 
 same : and if the expression be allowable, we may say that 
 the vital force in all cases acts according to its knowledge of 
 its rational designs ; though this knowledge is sometimes 
 passive or latent, and at other times, sensible or conscious. 
 But of this more hereafter. 
 
 From what has now been said concerning specific vital 
 powers, it will have been gathered that we advocate the 
 permanence of species : we do not believe that true specific 
 powers can by any process of development be transformed 
 from a lower to a higher species. The same species, as in 
 the case of man (who is the only organism which is defi- 
 nitely indicated in the Scriptures as a distinct species, 
 and there is no other possible source of information on this 
 subject), may present great varieties, by long residence in, 
 different climates, and other modifying circumstances : but 
 however greatly the two extreme tribes of human beings 
 
 P 3 
 
214 OKGANISMS, DUALISMS OF 
 
 may differ from each other, they have all characteristics 
 which broadly distinguish them from all other species of 
 animals ; and it is not .within the limits of our lengthened 
 experience, that any inferior creature can, by develop- 
 ment, become a man ; or that man can be actually degraded 
 to the condition of a brute beast 
 
 It is indeed very possible that many kinds of animals, 
 as the dog, though presenting varieties exceedingly unlike 
 each other, may all be derived from a common stock ; their 
 differences having arisen from the long continuance of 
 peculiar conditions : and this is rendered the more probable 
 by the marvellous transformations which are effected by 
 the breeders of cattle and by the horticulturist. In all 
 such transformations, however, we do not see any confirm- 
 ation of the notion promulgated by Lamarck, that by 
 gradual development all creatures may have been derived 
 from a lower grade. 
 
 The line of demarcation between plants and animals is 
 indeed very obscure ; and so it is between most contiguous 
 genera of organisms : they seem to fine away into each 
 other almost imperceptibly; a process which nature seems 
 to delight in, and which is so exquisitely beautiful in 
 luminous phenomena. Still, in all this intimate blending 
 together, there are certain broad and well-marked differ- 
 ences, which we have no reason to believe ever have been, 
 or possibly can be, metamorphosed into each other : a fish 
 and a mammal may fly like a bird, and a mammal and a 
 bird may frequent the water like a fish ; but the structure 
 of these different organisms are so different that we can- 
 not conceive that any mode of existence, however varied, 
 could convert one into the other. It is true, that we see 
 
CHEMICAL AND VITAL TOWERS. 215 
 
 as wonderful transformations in the metamorphosis of 
 various creatures : but in all such cases provision is made 
 in the structure of each for such developments, in order 
 to adapt them for successive modes of existence ; this 
 being the normal character of these particular species. 
 
 Each adopted species should be regarded as only pro- 
 visionally true, until it be proved to be a variety. But 
 even when species are correctly established, they cannot, 
 like chemical elements, be manifested as individual realities : 
 in the one case there is a fixity of character, which renders 
 this possible ; in the other there is an endless variation, in 
 accordance with the attributes of growth and reproduction. 
 
 In our present state of knowledge, we cannot mark the 
 limits of the varieties which make up definite species, 
 except in the case of man ; and therefore those who are 
 now actively engaged in investigating this difficult subject 
 are well occupied : hitherto their labours have been so far 
 successful as to have greatly reduced the number of pre- 
 viously acknowledged species, which doubtless is still 
 greatly exaggerated. But the tendency of their labour 
 seems to be toward the revival of Lamarck's hypothesis, 
 which, if substantiated, would reduce all our specific to 
 one universal vital power. Differentiations when car- 
 ried to extremes lead to a confused and perplexing state of 
 knowledge, but such unifications as an original oneness of 
 animated beings, and the identity of all natural forces, 
 tends to an absolutism which to the human intellect is 
 equivalent to an abnegation of all knowledge. 
 
 P 4 
 
216 
 
 CHAP. VIII. 
 
 MIND, OR CONSCIOUS POWER, THE HIGHEST PHASE OF 
 VITALITY. 
 
 Mind and Matter not heterogeneous. Mind differs from the other 
 Parts of the Organism only in Degree. The mutual Dependance of 
 Mind and Body. The Phenomena of Mind the Subject of Psy- 
 chology. Brutes have Minds. The Infant Mind, as regards Ex- 
 perience, a tabula rasa. Primary Knowledge intuitive. Evidence 
 of the Senses reliable : Inferences deceptive. Sensation and Per- 
 ception. Abstraction, or Mental Analysis of Knowledge. Ex- 
 perience, acquired Knowledge : communicable by Example, as well 
 as by Precept. Memory. The Subjective and Objective Factors 
 of Knowledge. Intuitive Understanding, or Common Sense. 
 Perfect Knowledge analogous to Instinct. A posteriori and 
 a priori Ideas. Conceptions or Abstract Ideas Their Denomi- 
 nation ; Colligation ; and Generalisation. The Moral Sentiments, 
 like Perceptions, are the intuitive Data of a higher Knowledge. 
 Brutes have moral and social Intuitions, or Instincts, as well as 
 Man. Man, in relation to the Morality of Brutes, stands in loco 
 Dei. The Nature of the Will or Conscious Power.- The Science 
 of Morality or Ethics. Conclusion. 
 
 IT is a proposition, says Dugald Stewart *, equally certain 
 and indisputable that " the phenomena of mind and those 
 of matter appear to be more completely heterogeneous 
 than any other class of facts within the circle of our know- 
 ledge." Body and mind are indeed generally regarded as 
 the antithesis of each other : that they are the opposite 
 
 * Encyclopaedia Britannica. Preliminary Dissertation, p. 10. 
 
MIND, OR CONSCIOUS POWER. 217 
 
 poles of animated beings, and capable of being separately 
 contemplated, cannot be denied ; but we do not recognise 
 that broad line of demarcation between them which is 
 commonly believed to exist. 
 
 In the usual acceptation of the terms body and mind, 
 the former is the living visible organism which discharges 
 all the animal functions ; whilst the latter is some un- 
 known spiritual existence dwelling therein, and exercising 
 all the faculties of consciousness: the mind, in short, is 
 conceived to be something sui generis, requiring to be 
 treated of separately from physiology ; and has, therefore, 
 been erected into the distinct science of psychology. This 
 distinction may be convenient in many respects ; but if 
 maintained, these sciences should be regarded as the 
 branches of a more general science, such as that of biology : 
 in this case, however, we should have to contend with the 
 same perplexity as occurs in statics and dynamics, the con- 
 tinual transition of one into the other ; for conscious and 
 unconscious are only distinguishing features, or different 
 phases, of the self-same vital power : and, as we shall soon 
 see, even the most exalted phenomena of consciousness are 
 capable of becoming passive or intuitive, that is, of con- 
 version into the unconscious state. 
 
 Mind is the intelligent or intellectual faculty, but still 
 it is the self-same power which actuates the body and 
 participates in all the organic functions. It is a phase, the 
 highest phase, of vital power, and as such is immediately 
 related to the highest development of the body, the cere- 
 bral organ ; the function of which is only concerned with 
 physical force in its most exalted phase, as the nervous 
 fluid : and it is only by the concurrence of this corporeal 
 
218 MIND, OR CONSCIOUS POWER, 
 
 nervous organ and the conscious vital force that those 
 actions and reactions take place that are manifested as 
 mental phenomena. So that, as our organism is not one 
 thing but a composition of forces, it follows that every 
 part of this whole must be similarly constituted: the 
 mind therefore is not an indwelling influence, but a dual- 
 ism of forces, the highest phase of organic existence ; a 
 diversity in unity, which is the essential condition of all 
 natural beings. 
 
 The individuality, or selfhood, of every chemical and 
 vital existence necessarily depends on this dualistic con- 
 stitution, without which it could not function ; and it is 
 the predominant force in such dualisms that imparts 
 thereto their peculiar or specific characters: and as the 
 properties of the latter become more complicated in or- 
 ganisms, so the creature or the subordinate parts of any 
 creature attain a higher degree in the hierarchy of nature. 
 Thus in the 'higher order of animals, the specific vital 
 power not only possesses a self-directive force, which 
 guides and superintends, according to its rational laws, 
 its vegetative, locomotive, and instinctive functions ; but 
 it is also a self-conscious power according to its degree. 
 It may belong to the lowest degree of consciousness, only 
 being aware of its sensations, and responsive to these 
 motives of action, and it may, thus far, be able to choose 
 between various possible modes of accomplishing its 
 desires ; and it may not only be conscious of all this, and 
 possess such an amount of understanding as constitutes 
 personal experience; but it may also be rationally conscious, 
 capable of interpreting the reason in nature, the laws 
 by which all cosmical powers are governed ; then it 
 
THE HIGHEST PHASE OF VITALITY. 219 
 
 becomes a rational will, the highest development of vital 
 power. 
 
 The will is not only a reason-directed force, but it is 
 capable of becoming conscious of this reason, and of 
 knowing not only that it is a force and can act, but also 
 of knowing for what purpose it acts ; and it knows when 
 it has accomplished its designs. Now we say all this of 
 the will, as if it were the sole force concerned in causation, 
 because it is the predominant, and therefore the more 
 conspicuous cause of the resulting effects : just as in the 
 motion of bodies, the propelling force rivets the attention 
 to the exclusion of the resisting force, which modifies the 
 result. The will) that is, the vital force as a free conscious 
 agent, is intimately associated with the brain, which acts 
 as the corporeal or basic force of the dualism : it is conscious 
 of physical impressions made on the brain, and according 
 to this knowledge it directs and puts forth the efficiency 
 of the cerebral force, which, as nervous energy^is discharged 
 on the muscles to be moved, thereby exciting them into 
 action. This operation is purely physical, and as such 
 must depend on the physical forces of the organism ; but 
 these forces are under the control and guidance of the 
 specific vital force, in order to perform such special actions 
 as may conduce to the creature's welfare or enjoyment. 
 
 That the concurrence of the will and cerebral force is 
 requisite for the due performance of mental actions, is not 
 only shown in the case of paralysis, when the organic 
 defect renders the mind impotent ; but also by the fact 
 that the energy of the mind is as mu.ch impaired by ex- 
 cessive mental exertion, as the strength of the body is by 
 any kind of exercise which induces great fatigue. But 
 
220 MIND, OK CONSCIOUS POWER, 
 
 here we must pause for the present, as we are anticipating 
 our subject too hastily; what we have been desirous of 
 pointing out is, that man, as well as all other creatures, 
 whether guided purely by instinct, or by acquired know- 
 ledge, is equally a dualism of natural powers ; and however 
 these may function, whether involuntarily and uncon- 
 sciously, or voluntarily and consciously, there must in 
 all cases be organic action and reaction. This may not 
 always be easily demonstrated; but it is a fundamental 
 truth ; and by keeping it at all times well in view, it may 
 ultimately enable us to solve the difficulty. Thus, in a 
 few words, we have endeavoured to indicate the relation 
 which subsists between Matter and Mind : and we now 
 proceed to enter more into details concerning mental 
 phenomena. 
 
 Brutes may in a sense be said to possess minds ; for they 
 have all the inferior faculties of the understanding, whilst 
 they are devoid of the higher capacities of abstraction and 
 of logical reasoning. Man enjoys the whole range of these 
 faculties, and he alone possesses a perfect mind : we there- 
 fore propose to make the human mind the more especial 
 subject of our inquiry, noticing in our progress those 
 faculties that are common to the brute, till we arrive 
 at that point where the two orders of mind part com- 
 pany. 
 
 In the earliest dawn of the infant's mind, as far as re- 
 gards actual knowledge, Locke has well likened it to a 
 tabula rasa ; ready for the reception of future inscriptions : 
 its condition is analogous to that of the conjugate germ- 
 cells, which are for all creatures so much alike, and apt to 
 assume various aspects according to the influence of their 
 
THE HIGHEST PHASE OF VITALITY. 221 
 
 respective specific principles. In what manner does the 
 infant mind begin to function ; how is its blank page in- 
 scribed with the elements of knowledge ? Locke main- 
 tained that knowledge is primarily acquired by and 
 through the medium of the senses ; and much as this 
 opinion has been combated, its validity has, we think, 
 never been satisfactorily disproved. This idea, however, 
 did not originate with Locke ; but it received at his hands 
 such admirable illustration, that he virtually made it his 
 own : " nihil est in intellectu quod non fuerit in sensu," was 
 an old maxim, to which Leibnitz * appended the proviso, 
 " nisi ipse intellectus." This addition, at first sight, looks 
 very like nonsense ; for how can a mind be within itself? 
 what is meant is, that knowledge may also originate im- 
 mediately within the mind ; that is, that a priori know- 
 ledge is possible ; but of this more hereafter. 
 
 If the human or brute mind could not intuitively inter- 
 pret the impressions made on the organs of sense by ex- 
 ternal objects, knowledge would be impossible ; but, as 
 constituted, the creature, when face to face with the out- 
 ward world, acquires a direct and immediate knowledge of 
 the import of its sensations ; -that is, as far as regards the 
 outward appearance of objects. 
 
 Many have written lightly concerning the value of sen- 
 sational knowledge, because it relates to phenomena which 
 are ever changing; but inasmuch as it is intuitive, and 
 not liable to the imperfection of logical knowledge, which 
 depends much on the individual reasoning power, it seems 
 rather to be deserving of the greatest reliance. At all 
 
 * (Euvrcs de Leibnitz, par Jacques, torn. i. f. 59. 
 
222 MIND, OR CONSCIOUS POWER, 
 
 events, by common consent, confidence is placed in the 
 testimony of the senses ; indeed its veracity will stand the 
 test of the famous criterion of Vincent of Lirens. But 
 surely the senses may be deceived ? Certainly not ; but 
 wrong conclusions may be drawn from the knowledge thus 
 obtained. Zeuxis painted grapes so naturally that they 
 deceived the birds ; whilst he himself, in turn, was 
 deceived by a curtain drawn by Parrhasius : the senses, in 
 both cases, gave a correct testimony that the appearance 
 was the same as would have been afforded by the objects 
 themselves ; but the birds and the painter were both deluded 
 because they judged according to experience. Had any 
 doubt arisen concerning the nature of the objects, as when 
 first seen before experience, the sight would not have been 
 trusted alone, but would have been aided by the other 
 senses : but such a proceeding, in the case of experience, 
 would be contrary to an important provision of Nature, 
 by which the intercourse with the outer world is greatly 
 facilitated; viz. that knowledge once acquired is trust- 
 worthy, otherwise we should always be doubting, and ever 
 learning. Nature herself is uniform ; and on this fact we 
 place great reliance : but she does not provide against 
 human devices, either artificial or moral ; these belong to 
 entirely different categories. 
 
 If there be no organic defect, sensational knowledge, 
 being intuitive, is invariably uniform ; not only for the in- 
 dividual, but for all creatures : and for man it affords the 
 foundation, or primary principles, of all natural know- 
 ledge ; for all such may immediately or mediately be traced 
 up to this origin. 
 
 How, it may be asked, can physical objects and mental 
 
THE HIGHEST PHASE OF VITALITY. 223 
 
 consciousness be brought into communication, so as to pro- 
 duce this presentative knowledge ? Each organ of sense 
 is so framed as to be capable of being acted on by peculiar 
 physical agencies ; by aerial and etherial undulations, and 
 the like : and the material impacts thus made on the 
 organs are conveyed by the nerves, and produce corre- 
 sponding physical impressions on the brain. Sometimes 
 these impacts are arrested in their progress towards the 
 brain, and are diverted by a reflex operation, so as only to 
 excite the efferent nerves ; as in the automatic movements 
 connected with the ganglia of the nervous system : and in 
 this case the impressions on the organs of sense do not 
 enter into consciousness. So that physical impressions may 
 come into concurrence with vital power in two modes : 
 either on the lower, as the unconscious phase ; or on the 
 higher, when the creature feels and knows what has 
 happened. Though, in the one case, the vital force is un- 
 conscious ; still it is a reason-directed force, acting on 
 given impressions according to a predetermined mode of 
 operation: so when this force is conscious, or a will, it 
 regulates its actions according to its acquired knowledge 
 in such manner as it may choose ; and when this choice 
 coincides with the ordinary routine of unconscious actions 
 it will be almost passive, that is, only slightly removed 
 from the phenomena of instinct. 
 
 This primary mental function is called sensation : and it 
 may be either active or passive, in respect to consciousness, 
 according as it is associated with the automatic or volun- 
 tary phase of vital power. It is well known that habit, or 
 intense preoccupation, renders us unconscious of many sen- 
 sations which must have been produced under the existing 
 
224 MIND, OR CONSCIOUS POWER, 
 
 circumstances : something more is, therefore, requisite 
 than the ordinary impressions on the nervous centres, be- 
 fore sensations become objects of knowledge. 
 
 Sensations are capable of being known, or are cognis- 
 able, just as bodies are capable of being moved : and as in 
 the latter case, a moving force must be applied before 
 motion can be produced ; so in the former, a conscious or 
 knowing force must act on the knowable objects ; a con- 
 currence which results in knowledge. Knowledge, there- 
 fore, is no other than a knowable object that is known ; 
 as motion, or rather, to speak more accurately, a corporeal 
 movement is a moveable body when moved ; in either 
 case the resulting phenomenon is not one thing, but all the 
 forces concerned therein are contained in, or co-exist in, 
 the phenomenon ; so that a known object or knowledge 
 is still that which may be farther acted on by conscious 
 force, with various degrees of intensity ; it is still as much 
 a knowable object as the original sensation itself. Since, 
 then, sensations partake of the nature of the physical body 
 of the organism, and the consciousness is a phase of the 
 specific vital force, it is evident that the mind, on its lowest 
 platform, is as much a dualism as any other organic 
 function ; thus conserving the universal correlation of cor- 
 relative powers. 
 
 The primary knowledge obtained through the medium 
 of sensation is called perception; and the energy of the 
 conscious force concerned therein is attention : without 
 some degree of attention there can be no perception. In 
 perception, we get the first glimpse of the mighty import 
 of the ideal or rational side of power ; for as the real 
 side, the physical efficiency of power seems to elude our 
 
THE HIGHEST PHASE OF VITALITY. 225 
 
 grasp in the higher mental phenomena, consciousness 
 gives us more and more insight into the character of that 
 pure reason, which is the basis of the ideal. As force be- 
 comes abstracted from natural powers, reason stands out in 
 stronger and brighter relief; until at length, under the. 
 magic influence of consciousness, force vanishes away, and 
 nought remains of power, but the abstract beau-ideals, the 
 designs only of that ineffable genius, which pervades all 
 the works of creation. 
 
 But it must ever be remembered that these wondrous 
 manifestations of the human mind are only the inter- 
 pretations of the reason in nature ; a part only, a glorious 
 part indeed, but not nature herself in her entirety. Ab- 
 straction is but a mental analysis, by which we are enabled 
 to examine the ideal side of nature; and by which we 
 become acquainted with logical forms, the fundamental 
 principles of all rational knowledge. Pure and exact, 
 however, as this knowledge is; it is, we conceive, all 
 derived from our primary and concrete perceptions : fun- 
 damental principles are contained therein, just as chemical 
 elements exist in compounds previous to their separation 
 by analysis; but they must be eliminated therefrom by 
 logical methods. When once obtained, we become so 
 deeply impressed by their simplicity, that we are apt to 
 regard them as essentially distinct and independent forms 
 of knowledge, as a priori truths, which are only knowable 
 by a species of intellectual intuition : we are, however, 
 inclined to think that perceptions are the only kind of 
 intuitive knowledge, and that as data, they enable us to 
 obtain the pure elements by logical processes. 
 
 But to return from this digression. Whenever purely 
 
 Q 
 
226 MIND, OR CONSCIOUS POWER, 
 
 passive sensations take place, instinctive actions follow : 
 they have answered their purpose ; the ordinary response 
 has been given, and they are consigned to oblivion. Not 
 so when they have arrested the attention of conscious 
 force, for then perception follows ; and when this occurs, 
 knowledge has been acquired, which is more or less per- 
 fectly appropriated, according to the degree of attention 
 exercised, and according to the number of the senses 
 engaged in the contemplation. Should the same object 
 be again perceived on another occasion, the same scrutiny 
 is not repeated; the creature already knows it, and a 
 single momentary glance Is sufficient to inform him what 
 it is, and his conduct is regulated according to this con- 
 viction. When a large experience has thus been acquired, 
 even by the brute, the voluntary actions may be con- 
 fidently directed thereby : and other brutes of the same 
 kind will depend on their more experienced elder, as an 
 authority which may be implicitly followed ; thus obtaining 
 by practical instruction a knowledge, which took their 
 guide a life-long application to acquire. 
 
 Experience then is only acquired knowledge, which for 
 the guidance of voluntary actions stands in the place of 
 instinct, (or intuitive knowledge, if it may be so called,) 
 which is the directive principle of involuntary functions. 
 How knowledge, when once acquired, can be retained 
 and made subservient to the will, as its reason-directing 
 influence, we cannot tell ; nor do we know how the vital 
 force can develop its organism, and utilise the same for its 
 various purposes ; nor indeed, for that matter, can we tell 
 how gravitation can concentrate and retain its energy 
 around a common centre, which increases on every addition 
 
THE HIGHEST PHASE OF VITALITY. 227 
 
 to the mass. This, however, we know, that the concur- 
 rence of the organic brain is a requisite factor in the 
 operation ; for if it be in any way deranged, knowledge 
 is lost ; and whether the derangement be a mental defect 
 or a physical inability to function, is of no consequence ; 
 for force cannot act without knowledge, and knowledge is 
 powerless without a simultaneous and co-existing force. 
 We do not pretend to offer a perfectly satisfactory ex- 
 planation of the retention of knowledge in the cerebral 
 region ; for we cannot demonstrate corresponding organic 
 phenomena: but if it be, as we suppose, that the con- 
 currence of corporeal, or physical forces, and of conscious 
 force is requisite in all mental functions, it is not im- 
 probable that the product of such concurrence may con- 
 tinue to subsist in the cerebral region, if not as a structural, 
 at least as a functional reality. The suggestion which 
 arises on the contemplation of this subject is, that as 
 grosser products are retained around and within corporeal 
 organs, may not the more etherial impressions be retained 
 by the brain, and even be more permanently durable as 
 less gross material. Whether this continuance be un- 
 changeably abiding or periodically renewed, like the 
 products of the vegetative organs, is beyond observation : 
 but the fact is undeniable, that knowledge obtained in 
 childhood remains till old age ; and during this long 
 period, the body has been repeatedly renovated, and yet 
 has retained its identity, not only of form and feature, 
 but even of extraneous marks and excrescences both arti- 
 ficial and natural. This is indeed a difficult, but a very 
 interesting problem. 
 
 It will have occurred to many that what we are referring 
 
 Q 2 
 
228 MIND, OR CONSCIOUS POWER, 
 
 to acquired knowledge, is usually ascribed to memory, as 
 a distinct faculty of the mind. Acquired knowledge is 
 the product of the action and reaction of the cerebral and 
 conscious forces : a product which is retained and utilised 
 by the will, as a guide in the exercise of its freedom. 
 Such a function may be called memory, and as the term 
 is so familiar to us, its employment may sometimes save 
 circumlocution ; but then it must be distinctly understood 
 that we do not regard it as a peculiar faculty, but only as 
 a state of consciousness. When knowledge is imperfect, 
 the memory is confused; but when the attention has 
 been intently ri vetted on an object, it becomes well 
 known, and the memory is perfect ; and knowledge thus 
 remembered is ever at hand to be utilised by the energy 
 of the same conscious force by which it was originally 
 acquired and appropriated ; in like manner as the organs of 
 the body are fabricated, and made to function by the same 
 vital force. 
 
 "We remember," says the author* of "Psychological 
 Inquiries," " nothing of what occurred in infancy. That 
 part of our life seems afterwards to be a blank in our 
 existence ; and it is not unreasonable to suppose that the 
 brain, like some other of the organs of the newly born 
 child, is in an unfinished state, and therefore not fitted to 
 retain the impressions made on it during any considerable 
 period of time." Again, "It seems that impressions made 
 on the organs of sense, and transmitted to the brain, 
 produce some actual change on the minute organism of 
 the latter, and that this is subservient, and in our present 
 
 * At pp. 60, 63, and 67 
 
THE HIGHEST PHASE OF VITALITY. 229 
 
 state of existence, essential to memory." In infancy, 
 man is on a lower platform of existence ; his organs and 
 their functions are like those of inferior animals; and 
 even when the senses are developed, they only serve to 
 assist automatic movements by reflex actions; and even 
 in the dawn of consciousness, when perceptions are first 
 evoked, they are feeble and transient as the passing 
 shadow ; indeed, if they were perfect and abiding, they 
 would be purposeless, for the helpless condition of the 
 organism could not avail itself of such knowledge. Nature 
 does nothing in vain ; knowledge is not needed by the 
 babe, consequently it acquires none, and the memory is 
 nil: but when the child becomes self-conscious, its sen- 
 sations excite vivid perceptions, accompanied by an earnest 
 curiosity, a craving thirst after knowledge, which is as 
 requisite for the mind as food is for the body : and as it 
 grows in knowledge, its memory acquires strength ; and 
 is at no period of life more energetic than during child- 
 hood, for then perceptions make the deepest impressions. 
 
 Before quitting the subject of perception it may be well 
 to briefly recapitulate what we have said ; for as all other 
 kinds of knowledge take their departure therefrom, it is 
 important that we should be rightly understood. 
 
 Sensation is one of the factors of perception, the other 
 is conscious force or will, which is one of the phases of 
 vital power, the principle which is concerned in all the 
 animal functions. When the vital force acts instinctively 
 (that is, according to the special laws of its innate but 
 passive rational guide), its energy goes forth in the ac- 
 complishment of its purpose by a reflex action of the 
 nervous system ; a mode of action similar to that of the 
 
 Q 3 
 
230 MIND, OR CONSCIOUS POWEK, 
 
 physical forces ; but when, by the acquisition of the ad- 
 ditional attribute of consciousness, the vital force becomes 
 also a conscious force or will, then it perceives and knows 
 the import of the sensations with which it comes into 
 communion ; and the result is voluntarily acquired know- 
 ledge, a new and independent guide for the regulation of 
 its conduct. The will, though a higher phase of vital 
 force, is not dispossessed of the attributes of the lower 
 phases : they are all parts of one and the self-same vital 
 power; and, therefore, within its sphere of activity, it 
 can exercise all its functions. 
 
 In respect to the two factors concerned in the mental 
 process of perception, Kant * entertained a notion some- 
 what similar. " There can be no doubt," he says, " that 
 all our knowledge commences with experience ; for what 
 could act upon the knowing faculty, and urge it to move- 
 ment, but the various objects of sense, which as raw mate- 
 rials are worked up into that knowledge of things which 
 we term experience?" But, as M. Cousin f remarks in his 
 " Lectures on the Critique of Pure Reason," " Kant is very 
 confused on this subject : one while he makes a distinction 
 between sensation and perception, regarding one as the 
 condition of the other ; and at another time he refers both 
 to one and the same faculty, the sensory." It was Jacobi { 
 who first detected this inconsistency of Kant ; and who 
 distinctly pointed out ' ( that the moment of immediateness 
 must remain for the mind the mediating agent, as a basis 
 
 * Critick of Pure Reason, tr. by Haywood. Introduction. 
 
 f At p. 25, 80. 
 
 J Chalybseus, Spec.Philosophy p. 60. 
 
THE HIGHEST PHASE OF VITALITY. 231 
 
 and condition of development." This Kant evidently lost 
 sight of, relying too much on the one factor of the under- 
 standing as the source of knowledge. In this respect he 
 was afterwards surpassed by Fichte, who made Leibnitz's 
 exception, nisi intellectus ipse, his rule ; and which ulti- 
 mately terminated in the pure idealism of the German 
 philosophy. On our view, the mind is a dualism, like all 
 other natural powers; and thus viewed, the gulph of 
 absolutism is avoided; we remain within the circle of 
 conditioned relations, making the system of nature the 
 unity out of which all diversity may be evolved. The 
 mind is part and parcel of the living organism : the brain, 
 a corporeal organ, functions physically through impressions 
 communicated to it by the nerves ; and the concurrence of 
 its products, or phenomena, with the conscious force results 
 in a diversity of perceptions or primary ideas. In these 
 ideas the organic, or objective, factor is at ^.maximum, and 
 the intellectual faculty, or subjective factor, at a minimum: 
 and however the relative proportion of the two factors may 
 vary, yet in every kind of idea (that is, in every kind of 
 interpreted form of knowledge) there must be an object 
 and a subject ; for an idea is a correlation of these correla- 
 tive factors. 
 
 The will can at pleasure objectify any kind of know- 
 ledge, by directing its energy thereon ; we say not, as is 
 usual, by fixing its gaze thereon, as if the will operated 
 by a species of intellectual vision : this would not convey 
 our meaning. We rather regard it as a conscious force, 
 which adds to the intellectual factor in perception another 
 proportion of its energy, whereby this factor becomes 
 more intensified ; and the knowledge becomes thus raised 
 
 Q 4 
 
232 MIND, OR CONSCIOUS POWER, 
 
 to a higher form ; it is no longer a perception) but a con- 
 ception. 
 
 From this it follows, that although a conception is a 
 higher order of idea or of knowledge, yet it is similarly- 
 constituted ; having a content and form, an object and 
 subject, and therefore is still related to the same dualistic 
 principle which obtained in a perception, though the 
 factors have different ratios : just as solids, liquids, and 
 gases are modes of the self-same substance ; though in 
 each the constituent physical forces vary in their relative 
 proportions. 
 
 Conceptions are abstract ideas ; and by their filiation to 
 perceptions, it is evident that they are derived from the 
 latter concrete ideas by abstraction ; and have therefore no 
 pretension to an independent origin. In forming concep- 
 tions there is a degree of intellect required, which tran- 
 scends the faculties of the brute : we begin now to analyse 
 knowledge, in order to ascertain what it is in itself; 
 whereas the knowledge of brutes is confined to the out- 
 ward appearance of things. But even in the attainment 
 of this knowledge, the consciousness passively exercises 
 many methods, which are at root the same as those which 
 are voluntarily and designedly employed in higher pur- 
 suits. Thus the comparison of perceived objects, as to 
 whether they are like or unlike, evidently takes place, 
 though unconsciously, in all attentive observations: the 
 creature sees at a glance whether it knows the object, or 
 not ; and if not, then succeeds a regular investigation by 
 each and all of the senses, which is no other than a mental 
 comparison with such objects as are already known in its 
 experience. Such comparisons are not accompanied by 
 
THE HIGHEST PHASE OF VITALITY. 233 
 
 that clear apperception which occurs in the conscious mind 
 in the case of abstraction ; it is, however, the same process, 
 though instinctively performed, that is followed in the 
 highest mental pursuits: thus, in logic, positive and nega- 
 tive propositions are only affirmations of similarity or 
 dissimilarity. These tacit and unconscious operations of 
 the instinct show that even on the lowest platform the 
 germ exists in the mind, which may possibly be expanded 
 into perfect intelligence. We have, indeed, many remark- 
 able facts on record concerning the understanding of 
 brutes, that seem to show that they are rational, though 
 not logical creatures ; their practical experience intuitively 
 applied, is sufficient for all their exigencies, and though it 
 does not amount to pure reason, it is a clear understanding, 
 which may not be unaptly called common sense. 
 
 There is another well-marked distinction between man 
 and the brute, in the faculty of speech which the former 
 exclusively possesses; and also in the capacity of intelligibly 
 expressing the language of his speech in written symbols ; 
 by which knowledge once acquired may be preserved and 
 accumulated from generation to generation. Objects of 
 all kinds, when represented by appropriate names, the 
 meaning of which has been correctly learnt, may be as 
 distinctly understood as if they had actually become known 
 by personal experience ; and thus it is that when the well- 
 informed visit foreign countries, all things seem so familiar 
 to them, that they do not experience those feelings of 
 curiosity and wonder, which so delight the uninformed 
 traveller. 
 
 This statement concerning oral and written language 
 may seem to contradict what has just been said concerning 
 
234 MIND, OR CONSCIOUS POWER, 
 
 mental phenomena, that they are always immediately or 
 mediately associated with organic actions and re-actions ; 
 but when the character of perceptions or primary ideas is 
 attentively considered, it will be found that knowledge 
 obtained in either manner follows a similar process ; there 
 are certain impressions made on the senses in both cases : 
 in the one case the impressions are excited by the actual 
 presence of the natural objects, in the other by conven- 
 tional sounds or visible symbols. Now in the former 
 instance, the interpretation by the conscious faculty is 
 intuitive ; we know the objects at once as far as regards 
 their appearance by a direct and immediate knowledge ; 
 and so the peculiar impressions made on the senses by the 
 words spoken or symbolised are also directly known, not 
 by an intuitive consciousness, but by an acquired know- 
 ledge of their meaning, which we have been taught by 
 precept or example. So that ultimately acquired know- 
 ledge and instinct are of the same import, as guides of the 
 rational will ; the one results from a voluntary, the other 
 from an involuntary operation of the same vital principle, 
 in the phase of the mental faculty ; and by these different 
 methods the same purpose is accomplished, the advance- 
 ment of human knowledge. 
 
 The communication of knowledge by oral and written 
 instruction is not confined to the primary ideas; for con- 
 ceptions and even science itself may be so taught and 
 learnt : thus, man may not only acquire a knowledge of the 
 lengthened experience of his teachers ; but also of that 
 which has been accumulated for ages, and handed down 
 by writing or tradition. Such knowledge, however, even in 
 its best estate, has not the certitude of intuitive knowledge, 
 
THE HIGHEST PHASE OF VITALITY. 235 
 
 which is not only perfect but invariable : it is liable to a 
 twofold error, either on the part of the tutor or of the 
 pupil ; and is a for the most part imperfect, being only in a 
 state of development. 
 
 When the mind has become familiar with any kind of 
 knowledge, whether that of perception or of conception, 
 that is, when any subject is well known, there is no longer 
 any effort or attention required in becoming conscious of 
 it ; or in the performance of actions directed thereby. 
 Such functions have become by habit, as it were, a second 
 nature, and are discharged as intuitively and instinctively 
 as those which are purely organic ; such a phase of activity 
 is more than that of mere memory, for the acquired know- 
 ledge must not only be recalled, but utilised in the per- 
 formance of particular actions, bodily as well as mental. 
 How long continued and laborious are the practical exer- 
 cises of the gymnast, and of the musician, before they 
 become expert performers; and, in like manner, how intense 
 the application of the mathematician and of scientific pro- 
 fessors, before they attain to a proficiency of their respective 
 knowledge ! But when either of them has finished his 
 course of instruction, he can perform the most elaborate 
 tasks, not only without laborious effort, but so easily and 
 intuitively, that though perhaps not absolutely, yet he 
 may be very nearly unconscious of his occupation. In 
 ordinary perceptions this is of constant occurrence, so 
 that what in infancy required much attention and instruc- 
 tion to learn, is in after life a purely automatic action of 
 the senses; as, for example, in walking and reading. Thus, 
 hard-earned knowledge, even that beyond the reach of 
 most men, may descend into a species of instinct, simi- 
 
236 MIND, OR CONSCIOUS POWER, 
 
 lar to that which guides the functions of very inferior 
 animals. 
 
 This wondrous result is very consistent with the view 
 concerning vital power which we are advocating. The 
 organic principle is a reason-directed force, which in its lower 
 phase is unconscious of its innate and unerring reason ; 
 whilst in its higher phase, it is capable of adding thereto 
 acquired knowledge, as an extra-rational guide, in conse- 
 quence of its additional attribute of consciousness : this 
 accession of acquired knowledge, which enlarges the 
 creature's field of action, is so appropriated and assimi- 
 lated by long experience, that it becomes part and parcel 
 of the creature's individual instinct or intuitive knowledge; 
 and as such it is ever prompt to guide and direct the exer- 
 cise of its efficiency. And thus we learn that physical 
 forces and conscious forces, that is, matter and mind, are 
 but the extreme dualisms of powers; the opposite poles, as 
 it were, of natural bodies. 
 
 It has already been stated that by perception we become 
 acquainted with natural objects ; and that by distinguish- 
 ing these objects by peculiar names, man is enabled to 
 communicate knowledge to his fellows : such names, how- 
 ever, only denote the actual objects, as they appear in 
 their individuality to the senses ; and are, therefore, 
 purely phenomenal, imparting no knowledge of what 
 things are in themselves. All these objects have peculiar 
 properties, or characteristic attributes, and each kind of 
 property affects some one or other of the senses in a special 
 manner; and thus it is that the properties of bodies 
 become mental objects : and when the conscious faculty 
 diverts its attention to only one particular property, to 
 
THE HIGHEST PHASE OF VITALITY. 237 
 
 the exclusion of all others in the various bodies under 
 contemplation, it abstracts this property by a process of 
 mental analysis ; and the knowledge thus obtained is an 
 abstract idea, which is secured and appropriated as a 
 mental object by being named. Abstract ideas are the 
 formal types by which many primary or concrete ideas 
 may be colligated together into one kind or class ; and by 
 a repetition of this act and by denomination, many colli- 
 gations are obtained, which in turn may be associated 
 together and designated by a general or class name. 
 There is no limit to such a process of generalisation, until 
 the summum genus of knowledge, the science of the sciences 
 or philosophy, is attained. The individual sciences are so 
 many subaltern genera; and each of these is a logical 
 universal, which has its own noun- substantive or funda- 
 mental idea. 
 
 These fundamental ideas, and their rational laws or 
 axioms, according to which they function, are by many 
 regarded not as elements arrived at by the mental analysis 
 of concrete ideas ; but as pure a priori ideas innate in the 
 mind, and perfectly independent of the sense-perceptions, 
 being manifested only by intellectual intuition. Or in 
 other words, knowledge is supposed to be of two distinct 
 kinds : the one derived immediately from the outer world 
 by the senses, and so termed empirical or a posteriori, and 
 partaking of the variableness and incertitude which cha- 
 racterises phenomena ; the other, relating only to the 
 principles of things, is regarded as a priori and independent, 
 possessing the criteria of necessity and universality. As 
 regards the universality of fundamental ideas, inasmuch 
 as each of these ideas is the principle of its own system or 
 
238 MIND, OR CONSCIOUS POWEK, 
 
 logical universal, it must needs be associated with or exist 
 in each and all of such system : and as regards their 
 necessity, it can only mean that this form of knowledge, 
 this interpretation of one of the reasons in nature, is a 
 perfect law, which when followed is an invariable guide, 
 necessarily precise and definite ; it is not a mere <f blind or 
 fated necessity, but a necessity of reason or logical 
 sequence." The criteria of a priori ideas, if used in such 
 a sense, are very intelligible ; and accord with our notion 
 of the constitution of mental phenomena. A priori ideas, 
 we conceive, are the elements of concrete ideas ; and con- 
 sequently must pre-exist in them ; though we are ignorant 
 of them, until they have been reached by successive in- 
 ductions: but when thus obtained they may be re-combined 
 by deduction, so as to demonstrate many particular ideas 
 previously unknown ; just as we can unite elements to 
 form chemical combinations, which have not hitherto been 
 detected in nature. 
 
 The Rev. Baden Powell has remarked that " pure rea- 
 son out of his own resources may, indeed, create theories 
 apart from all observations of nature ; but to make them 
 applicable to anything in nature, such creations of the mind 
 must necessarily and universally involve some small as- 
 sumption of material properties, or mechanical conditions ; 
 which can only be in some form or another ultimately 
 derived from observation : what is borrowed may be very 
 little ; but it must be something." And again, f< funda- 
 mental ideas are not a priori, or antecedent to all experi- 
 ence; they are principles established in the mind by 
 previous abstractions, remotely derived from previous 
 experience." 
 
THE HIGHEST PHASE OF VITALITY. 239 
 
 For these reasons, we accord with those who think that 
 the assumption of the intuitions of the pure reason by a 
 special faculty of the mind is not required to explain the 
 nature of fundamental or a priori ideas ; it complicates a 
 subject already sufficiently intricate, by introducing an 
 additional, and as we conceive superfluous principle. 
 There has, indeed, ever been a disposition to magnify 
 the rational faculty as a distinct and independent energy, 
 apart from all the other faculties of the mind ; a something 
 which can directly see and comprehend logical objects, as 
 external physical objects are immediately apprehended by 
 perception ; but such a notion degrades the human intel- 
 lect to a mere instinct, increasing its certitude doubtless, 
 but removing from it those logical exercises by which the 
 mental, like the corporeal faculties, are urged on to work 
 out their own progress towards perfection. Numerous as 
 the various phases of knowing and willing are, they are all 
 one and the same conscious vital force or will : and though 
 this will, according to its degree, whether of the brute or of 
 man, has, in each, various capacities, all of these lie dor- 
 mant in the first period of existence, and are only gradu- 
 ally developed ; just as the various organs of a creature are 
 evolved out of the self-same germ. And it is not, therefore, 
 surprising that the specific power of man should in both 
 cases exercise its faculties in a similar manner; that the 
 mind should increase in knowledge until mere consciousness 
 brightens into the full light of science ; just as the germ 
 expands and grows until the body acquires the stature and 
 strength of maturity. 
 
 Man is, as Bacon has well said, but the interpreter of 
 nature. He must be indebted to Nature herself, of which 
 
240 MIND, OR CONSCIOUS POWER, 
 
 indeed he is a part, for the data or primary principles of 
 his knowledge : and having acquired these data, his 
 rational faculty, a reason-directed force which functions by 
 logical methods of which it is conscious, elaborates there- 
 from the pure elements, or principles, of knowledge. 
 
 In the preceding remarks, we have used much repetition, 
 but on so intricate a subject it is not easy to express one's 
 meaning with the precision that is desirable. We will 
 now turn our attention more particularly to that phase of 
 vital power which, as conscious force, acting freely accord- 
 ing to self-acquired knowledge, is known as the will. 
 Much has been written on this subject, but very unsatisfac- 
 torily. The will and instinct are only different phases of 
 the same special force, as this is also a phase of the 
 same vital force which operates in organic functions. Will 
 is the phase of vital force which is directed by acquired 
 knowledge ; as instinct is the same force directed by un- 
 conscious reason, or rather by reason of which it is un- 
 conscious. And thus it comes to pass, that according to 
 the degree of knowledge, so is the freedom of the will : 
 for knowledge is power; that is, the capacity of acting 
 with corresponding efficiency. It is well known that as 
 our knowledge of nature is enlarged so are we enabled to 
 subject her forces, and make them subservient to our pur- 
 poses : as is exemplified, in modern times, by numerous 
 inventions ; but more especially by those of the steam- 
 engine and the electric telegraph. 
 
 This view greatly simplifies our notions concerning man: 
 it shows that whilst he is the most exalted of natural 
 beings, he is in no way disconnected therefrom, otherwise 
 than in possessing the additional attribute of a rational 
 
THE HIGHEST PHASE OF VITALITY. 241 
 
 consciousness. Even in the extreme case of mans re- 
 sponsibility to a higher power for his conduct, we do not 
 see that dissimilarity between man and the brute, as is 
 usually insisted on : of course, the morality of man is of a 
 higher standard than that of the brute, in accordance with 
 the superiority of his intellect ; still, in their character, they 
 are analogous, though not identical. Amongst domestic 
 animals (we might perhaps have said among all animals, 
 but we are not so well acquainted with the ferae natures) 
 we see the laws of nature concerning self-preservation 
 and property followed instinctively, as by man rationally : 
 and likewise we have on record many instances which 
 indicate an instinctive appreciation of social rights and 
 wrongs. And when brutes have been trained up to per- 
 form certain actions, they learn submission to the will of 
 their masters ; so as to do their duty obediently, even 
 when contrary to their inclinations : if they do so with 
 docility, it is well with them ; but if they obstinately 
 resist, rebelling against authority, they are conscious that 
 they have done wrong, and knowing the penalty for so 
 doing, they strive to avoid the impending retribution. In 
 short, man stands towards the brute in loco Dei, by a 
 delegated power ; or at all events by a power, which is 
 the necessary consequence of his superior knowledge. 
 Accordingly man frames laws for the conduct of his depen- 
 dents; and instructs them therein, by such practical teach- 
 ings as they are capable of understanding : and when the 
 brute has learnt his duty, and the consequence of dis- 
 obedience, man expects from him the same submission to 
 his will that Deity demands from man under similar 
 circumstances. Are we not then justified in maintaining, 
 
242 MIND, OK CONSCIOUS POWER, 
 
 that even as regards morality, in relation both to society 
 and to Deity, man is not perfectly insulated from the other 
 works of creation : he differs from them, indeed, as a being 
 of a higher order, enjoying accordingly greater liberty 
 in the exercise of his more exalted condition ; but he only 
 differs in dgree : he possesses more attributes than any 
 other natural being ; but still he is a part of the same 
 universal system. 
 
 Although the will is thus connected with other forces, 
 its modes of operation are so various, so free, ond often- 
 times so capricious, that the results of its action cannot 
 be calculated upon with any degree of certainty : these 
 actions may be recorded in tables of statistics, and the data 
 derived therefrom may serve for abstruse calculations ; 
 but the results thereof will not be truths, but only proba- 
 bilities. It is, therefore, evident that the phenomena in 
 which such a force is concerned cannot be dealt with like 
 tttose of the physical, and other unconscious forces ; which 
 are not free to choose the special rational guide of their 
 actions, but always under given conditions act in a pre- 
 determined manner : if we can have a science of such 
 phenomena, it must rest on very different principles, which 
 cannot relate to what is and must be ; but to what may be, 
 and ought to be: and this will involve us in an entirely 
 different field of knowledge than has hitherto engaged our 
 attention. 
 
 There are three kinds of human knowledge ; the ab- 
 solute, the relative, and the contingent : the source of the 
 first is supernatural, and can only be attained by Divine 
 communication ; that of the second is in nature, or rather 
 in that part of nature which is regulated by fixed and im- 
 
THE HIGHEST PHASE OF VITALITY. 243 
 
 mutable laws ; whilst the last source arises in the free and 
 variable actions of voluntary beings. Divine knowledge 
 consists of perfect truths ; natural knowledge, of reliable 
 facts ; whilst man-knowlege is concerned only with proba- 
 bilities, which partake of the imperfections of all human 
 inventions and institutions. If we frame anthropological 
 sciences, they can only serve to show what the actions of 
 man ought to be ; and what indeed they would be, if his 
 actions were regulated by the perfect laws which Divine 
 wisdom has promulgated for the guidance of his will: 
 would man but cheerfully submit to these laws, then his 
 conduct would be as perfect, and as logically intelligible, 
 as all the physical operations of nature ; because then all 
 natural forces, both voluntary and involuntary, would be 
 governed by the rational laws of the Creator. 
 
 The moral sciences are, therefore, only possible when 
 based on the principles divinely revealed ; or on those 
 natural principles, which are latently and passively opera- 
 tive in human nature, and of which we have frequent in- 
 stinctive glimpses : both of which are fundamentally the 
 same, though the latter are very obscure. In construct- 
 ing such sciences, when we have determined the respective 
 noun-substantive or principle, we cannot do better than fix 
 our attention on the physical sciences and follow their 
 guidance. As- the motions of material bodies form the 
 subject-matter of physics, so it will be found that the 
 actions or conduct of voluntary creatures is the theme of 
 moral science. Ethics, a well known and long established 
 science, gives the name, and indicates the character of its 
 contents phenomenally ; but it does not point out the inner 
 constitution of moral actions, nor the modus operandi by 
 
 B 2 
 
M4 MIND, OR CONSCIOUS POWER, 
 
 which the varied particulars of its universal are produced : 
 in short, it does not deal with the science of morals in its 
 causal, or, as we should say in physics, its physical aspect. 
 Is then a moral action like a material motion ; can it be 
 a composition of forces ? And if so, what are these forces 
 and their reason-directing laws ? 
 
 In the functions of an organism we found a dualism of 
 forces, which could be formulated according to the arche- 
 typal correlations ; thus : 
 
 Organic body + Vital force = Organic function. 
 Muscular force 4- Volition = Muscular action. 
 Material resistance + Muscular action = Locomotion. 
 
 Or, to sum up all the subordinates in a general expression, 
 Corporeal forces + Vital force Organism, 
 
 the science of which is biology, and its branches physio- 
 logy and psychology. 
 
 Now it is evident that Ethics ranges itself as a science 
 parallel with Biology ; and is, as we have said, the science 
 of conduct ; that is, of voluntary actions : but we have to 
 seek for the forces concerned in producing the resultant, 
 and of which they are the component parts ; and therefore 
 must be basic and typal correlatives. We can be at no 
 loss to find the specific or typal force in the will ; but its 
 correlative is not so apparent : we are inclined to think 
 that it can be no other than sensation, which, as appetite, 
 affection, passion, or some other kind of sensation, is the 
 inducement or motive which enters into concurrence with 
 the wil^ in determining any particular conduct ; and all 
 these passive or basic forces may be classed together as 
 
THE HIGHEST PHASE OF VITALITY. 245 
 
 emotions. So that the forces concerned in moral actions 
 seem to be the will and emotions : the former the specific 
 force, a phase of vital force ; and the latter the basic or 
 corporeal force of the dualism, which, therefore, can be no 
 other than the highest function of organic being. The 
 dualisms may be stated as : 
 
 Emotion + Will = Conduct, or Moral action. 
 
 Had we followed the precedent of electricity and mag- 
 netism, we might have erected the moral forces into two 
 distinct sciences ; and in so doing we should have been 
 also justified by the example of rational mechanics, as 
 follows : 
 
 Magnetism and Electricity. 
 
 Statics and Dynamics, branches of Cinematics. 
 
 Pathematics and Thelematics, branches of Ethics. 
 
 But we do not think it expedient, as already stated, to 
 adopt the constituent forces as principles, on which sciences 
 may be constructed : for the dualism or universal, which 
 is the legitimate subject-matter of systematic knowledge, 
 includes the forces and all that concerns them ; which 
 constitutes, indeed, the diversity in unity. 
 
 From what has been said concerning the forces engaged 
 in moral actions, we are not to suppose that the personal 
 acts and deeds which are associated with, or immediately 
 follow voluntary determinations, are the subject of moral 
 science ; any more than locomotion, or any other muscular 
 operation, can be referred to the forces concerned in the 
 mental process of perception, which precede the bodily 
 functions. The moral phenomenon is produced by the 
 operation of the moral forces, and is as such manifested 
 
 R 3 
 
246 MIND, OR CONSCIOUS POWER, 
 
 to the mental consciousness, and as knowledge may become 
 the guide to direct certain corporeal actions or not, accord- 
 ing to the desire of the will ; just as in the case of ordi- 
 nary sensational perceptions, it rests with the decision of 
 the will whether this knowledge shall terminate in muscular 
 activity or not : and hence it is that a breach of the moral 
 law is as effectually accomplished by the conception of a 
 sinful desire, as in the actual fruition of the lust. In the 
 case of moral action, the conscious force or will is of a 
 higher order of intelligence than in those sensational 
 perceptions which are associated with the emotions of 
 pleasure and pain ; for it not only knows the present 
 emotion, but it is also capable of judging of its tendency 
 to right or wrong> in consequence of its knowledge, which 
 is either intuitive or acquired according to its position in 
 the scale of morality. In general the will is free and 
 paramount, so that it may act or not, as it may choose 
 according to its moral knowledge ; but it is not absolutely 
 so in all cases ; for the pathematic force may be so intense 
 and overpowering, as to usurp the ordinary dynamic posi- 
 tion of the will, thus carrying all before it, and imparting 
 its own character to the resulting act and deed. Thus a 
 well-informed and regulated will controls and moderates 
 the emotions, even when these springs of action are vehe- 
 mently excited ; whilst a less determined will, under the 
 same circumstances, will be hurried away headlong by 
 the passions. In short, in ethics as in physics, we must 
 search in the character of the resulting actions for the 
 relation which the constituent forces bear to each other ; 
 and according to their relative proportion, so is the aspect 
 of the phenomenon. 
 
THE HIGHEST PHASE OF VITALITY. 247 
 
 It must not, however, be forgotten that the phenomena 
 of ethics, like those of all other organic functions, are 
 essentially vital or related to animated beings ; and that in 
 the performance of any of these functions there must be 
 a motion from a nervous centre as well as to it; that 
 there must be some kind of corporeal or organic force 
 associated with some phase of vital force in every function 
 of the creature ; and that it is only through a knowledge 
 of the functional phenomenon that we can gain an insight 
 into the nature of the forces concerned therein: or, in 
 other words, the forces are causes, and we can only know 
 the latter by their effects, for such is the limited character 
 of human knowledge. 
 
 The subject of ethics, taking this term in its largest 
 signification, as including all moral actions, individual, 
 social, and political, is exceedingly interesting; but it 
 would require more space than we have hitherto occupied 
 to impart our views thereon with any prospect of rendering 
 our meaning intelligible. Happily, in the circumstances 
 of the case, this is not necessary : for ethics, as an anthro- 
 pological science, is so perfectly distinct from the philosophy 
 of nature, that we can avail ourselves of this distinction to 
 postpone its consideration. But before concluding, we 
 cannot refrain from repeating, that though as a science 
 ethics is so peculiar, yet it is still an essential part of the 
 universal system ; and that, though its principles are largely 
 concerned in human affairs, they are not absolutely re- 
 stricted to man : for as in man himself the laws of these 
 principles are clearly foreshadowed in his natural estate ; 
 so are they fundamentally concerned in the constitution 
 and instincts of conscious brute creatures. 
 
 B 4 
 
248 
 
 CHAP. IX. 
 
 THE IDEAL SIDE OF NATURAL POWERS MANIFESTED 
 AS FORMAL KNOWLEDGE : THE LOGICAL INTERPRE- 
 TATION OF THE REASON IN NATURE. 
 
 The rational Forms of Nature give the fundamental Principles of 
 the abstract Sciences. System, or the classified Order of Degrees, 
 the most abstract Idea of Nature. The Knowledge of such a 
 System is Science or Logic. All the Sciences are based on the 
 Principles of Logic. The Definitions of Logic. Aristotle's Dictum 
 unjustly denounced. Logic relates only to the Forms of Things, 
 and not to Things themselves. Logic, like all Sciences, formed by 
 Induction ; and functions by Deduction. The Character of Genus 
 and Species Universals and Particulars Extension and Inten- 
 sion. A Proposition ; and its Terms, the Subject and Predicate. 
 The various Kinds of Propositions. The Syllogism Its three 
 Propositions, the Major Premiss, the Minor Premiss, and the 
 Conclusion. The cardinal Propositions; how symbolised. The 
 Quantification of the Predicate. The Formulas of Logic. Appli- 
 cation of Algebraic Notations to Logic. That of Professor Boole 
 not satisfactory, but his Suggestion important. Conclusion. 
 
 HITHERTO oar attention has been engaged in the con- 
 sideration -of natural beings as forces; which are made 
 known to us, as actual realities, by the physical impressions 
 which they make on the senses, w hereby they become to 
 us objects of knowledge. This, however, is a one-sided 
 view of nature ; these forces are not mere efficiencies, but 
 reason-directed forces, which are a law unto themselves : 
 and as we formerly considered the forces apart from their 
 reason, we now purpose to direct our attention to the lat- 
 

 IDEAL FORMS OF NATURAL POWERS. 249 
 
 ter, to the ideal side of power ; which, as formal principles, 
 are capable of being known as abstract ideas. 
 
 In the foregoing survey we saw that, various and mul- 
 titudinous as natural bodies are, they can be gathered 
 together into characteristic groups, and so classified as to 
 form one common system; and also, that probably this 
 system of nature may be co-ordinated with another sys- 
 tem of supernatural beings: but be this as it may, as 
 regards natural bodies, the system of nature is a universal 
 system ; it is the highest generalisation of material things, 
 a unity in diversity, and therefore capable of being un- 
 folded into the most minute particulars. 
 
 On this systematic principle, each subordinate generic 
 part of the whole may also be regarded as a universal, 
 since it embraces everything of the same kind: so that as 
 Cosmology is the knowledge of the system of nature, that 
 is, of the highest natural universal ; so the various natural 
 sciences imply the knowledge of the particular or subor- 
 dinate universals. Such sciences, however, as their respec- 
 tive names import, relate to forces, the real content of 
 natural powers ; or rather, to speak more correctly, they 
 treat of the concrete powers, the realities themselves, 
 though the form, by which knowledge only is possible, is 
 concealed by the potential content, which is more promi- 
 nently conspicuous : but when forces and their material- 
 istic attributes are abstracted, we have only the ideal forms 
 of nature remaining; the universals of which give the 
 pure exact sciences, systems of fundamental principles. 
 
 " With all our admiration," says the late lamented 
 Archer Butler *, " for the energetic labours of the great 
 
 * Lectures on the History of Ancient Philosophy, vol. ii. p. 55. 
 
250 IDEAL FORMS OF NATURAL POWERS 
 
 naturalists of our day, and for the advances which the 
 physical sciences are receiving through their combined 
 exertions, we cannot refuse to see, and in all quarters 
 the conviction is gaining strength, that the world of 
 ideas is in proportion eclipsed. This huge material uni- 
 verse, with all its labyrinth of laws, seems to fetter and 
 entangle us: we are so overwhelmed by weight and 
 motion, that matter and being become equivalent terms ; 
 and we cannot allow the existence of a world to which 
 these material attributes are not attached." These re- 
 marks were called forth on the contemplation of Plato's 
 doctrine of ideas, the eternal laws and reasons of things. 
 There is, however, some indistinctness concerning this 
 doctrine as it has descended to us : but which, indeed, 
 seems to have been original; for Plutarch maintained 
 that the ideas of Plato were not distinct realities, but 
 simply divine conceptions of order ; whilst, on the other 
 hand, Aristotle so understood these ideas, as to treat of 
 them as true and real existences. At all events, this 
 twofold aspect of things has always divided philosophy, 
 according as the subject is regarded from the real or ideal 
 point of view : thus, in the present day, some maintain 
 that the world subsists only as ideal forms, manifestations 
 of the thinking intellectual mind ; whilst others regard the 
 universe as a world of dynamical forces, functioning, ac- 
 cording to laws, as cognisable phenomena. 
 
 According to our view of the subject, nature is a 
 system of finite conditioned powers ; and in this system 
 alone can we look for oneness, which is not an absolute, but 
 a diversity in unity or a universal. Each part of this 
 system is a dualism of powers : a single natural power is 
 
MANIFEST THE REASON * IN NATURE. 251 
 
 not known to occur in an insulated or elementary state ; 
 and, indeed, probably cannot so exist out of relation with 
 other powers. This combination of powers takes place 
 only between those that are antagonistic: this mutual 
 opposition occasions the limitation to which all natural 
 forces are subject ; and it explains why natural bodies can 
 undergo internal changes, as well as those changes re- 
 sulting from the concurrence of several bodies. 
 
 When we regard nature in its totality, as a system or 
 classified arrangement of natural bodies ; and by the 
 mental process of abstraction, already considered, eliminate 
 therefrom all the real content of co-ordinated forces, there 
 only remains the forms of these bodies, the reason in nature, 
 which is knowable to the human mind as the idea of order 
 or system. This is the highest generalisation of abstract 
 ideas ; and it corresponds with the system of forces : both 
 of which conjoined constitute the system of nature. 
 
 But what is system in itself or per se? It is the logical 
 order of rational forms, the code of rational laws, which 
 conjoined with specific forces, are powers. These forms 
 of rational powers, when interpreted by the mind, are 
 abstract ideas, pure formal knowledge : and the knowledge 
 of the order, or system, of such forms, is systematic know- 
 ledge or pure science ; science in itself, the science of the 
 sciences, or Logic. 
 
 If we construct a science of a special abstract idea, 
 pure science or logic, as the summum genus, must underlie 
 and fashion it in all its parts : thus the science of number 
 and of space are systems of their fundamental ideas ; framed 
 on definitions, postulates, and axioms by the logical method 
 of induction ; and functioning when thus constructed by 
 
252 IDEAL FORMS OF NATURAL POWERS 
 
 deductive demonstrations. The only difference between 
 these sciences and logic is, that some special idea is conjoined 
 with the generic idea of system : thus arithmetic is the 
 science or logic of number ; as geometry is the science or 
 logic of space. And so it is in the case of the physical 
 sciences ; the principle of order, or system, occurs in all ; 
 and, consequently, the science of this principle must be the 
 universal basis on which all are founded : and thus it is 
 that the pure formal sciences are applicable to all concrete 
 knowledge ; and therefore are so eminently disciplinary 
 and propsedentic. 
 
 Logic has of late years attracted considerable attention, 
 having been rescued by several able writers from the 
 contempt into which it had fallen, through the ignorant 
 application of the syllogism. It is to be feared that there 
 is still, with very many, an imperfect apprehension of the 
 character and functions of logic : and this may in some 
 measure be attributed to its being regarded not as a pure, 
 but as an applied science ; an art only useful in evolving 
 conclusions by empirical formulae from all premises what- 
 ever, not only from those which are based on statistical 
 averages, but even from those which rest on the vaguest 
 probabilities. Whereas logic can only function accurately 
 and with certitude when its data have been firmly esta- 
 blished by its own preparatory processes of induction ; 
 and until these premises have been obtained, the con- 
 clusions must frequently end in absurdities : but such 
 must be charged to the incapacity of the workman, and 
 not to his instrument. 
 
 The uncertain position of logic cannot be better illus- 
 trated than by enumerating its various definitions, which 
 
MANIFEST THE REASON IN NATURE. 253 
 
 have appeared in recent works on this subject; but we 
 must rest content with three of standard authority. 
 "Logic," says Archbishop Whately*, "is the science df 
 reasoning." According to Mr. John S. Millf, "Logic is 
 the science of the operations of the understanding, which 
 are subservient to the estimation of evidence; both the 
 process itself of proceeding from the known to unknown 
 truths, and all other intellectual operations, in so far as 
 auxiliary to this." And lastly, Professor Thomson J says, 
 "Logic is the science of the laws. of thought: " in some 
 places he speaks of logic as "pure logic," and in others he 
 prefixes the words " formal " and " necessary " to the laws 
 of thought ; but the simpler expression is the best. 
 
 Now it will not, we think, be disputed that tlwuglit is 
 the product or result of the thinking faculty ; and that it 
 is, therefore, analogous to motion, which is the effect of a 
 moving force ; and if so, this analogy will enable us to 
 express more clearly our comments on these definitions. 
 The science of motion is Cinematics. Should we then 
 define cinematics as the science of moving; or as the 
 science of the operations of moving, which are subservient 
 to the estimation of the change in space, both the process 
 itself of proceeding from a state of rest to motion, and all 
 other moving operations in so far as auxiliary to this : or 
 lastly, that cinematics is the science of the laws of motion : 
 it would be evident that there is some deficiency in these 
 definitions. There can be no hesitation in affirming that 
 the ideas of thought and of motion imply an opus operatum : 
 that the science or systematic knowledge of these compre- 
 
 * Elements of Logic, p. 1. f A System of Logic, vol. i. p. 11. 
 
 I Outlines of the Laws of Thought, p. 3 j 
 
254 IDEAL FORMS OF NATURAL POWERS 
 
 Lends not only their phenomenal appearance, but also the 
 forces concerned therein, and the laws by which they 
 operate. The author of " The Laws of Thought " must 
 have been aware of this distinction, for he observes in 
 another place, that "pure logic enounces the laws we 
 must observe in thinking;" so then the laws belong to 
 the thinking agent, and not to the thoughts, which result 
 from the activity of the agent : in the above illustrations, 
 therefore, the tentative and probationary definitions do 
 not directly appertain to cinematics, but only mediately as 
 comprising dynamics, the force and the laws of force ; and 
 so likewise, the definitions above quoted do not concern 
 formal ideas or thoughts, but the cause, or thinking force, 
 and the laws by which it is regulated when it functions. 
 
 When we contemplate nature, and make therefrom 
 certain abstractions, we objectify them or make them 
 objects of knowledge ; and as such they become part of 
 the mind, and subject to its conscious faculty : now this 
 faculty is only a phase of vital force, one of the natural 
 forces which act and react according to innate rational 
 laws ; but being also a self-conscious force, it is capable 
 of knowing the logical methods which are followed in its 
 rational operations; for whilst all other forces act in- 
 stinctively and unwittingly, the mind, in' its intellectual 
 moods, acts voluntarily and consciously. Reasoning, there- 
 fore, is a free-will exercise of consciousness, according to 
 an acquired knowledge of the rational laws which regulate 
 the entire system of nature ; an activity which must 
 pervade all logical operations. But reasoning alone, or 
 the exercise of the thinking faculty, does not give logic, 
 but simply knowledge ; nor is logic the formal ideas, but 
 
MANIFEST THE REASON IN NATURE. 255 
 
 both are conjoined to make logic, which is the knowledge 
 of such a system. The system of forms, therefore, fur- 
 nishes the objective content of logic, whilst its subjective 
 efficiency is derived from the mind. So that, whilst in 
 the pure formal sciences the whole subject is concerned 
 with abstract ideas, the mind engaged therein is regarded 
 as merely an extraneous spectator, but it is not so; it is 
 the logical mind that enables these abstractions to function 
 according to logical laws, and without it there could be 
 no science; just as in physics its rational laws could not 
 become objects of knowledge unless manifested in pheno- 
 mena, which are the operations of efficient forces. 
 
 If pure abstract system, or the system of abstract ideas, 
 be the fundamental principle of logic, all such ideas can 
 only be related to each other, in regard to the various 
 degrees or order of the system : so that the objects with 
 which logic is concerned are no other than the abstract 
 terms of classification. These objects are successively 
 developed in the process of generalisation ; and as they 
 are evolved it is requisite that they should be individua- 
 lised by appropriate denominations) and clearly distin- 
 guished by accurate definitions. During this development 
 their relations towards each other in respect to extension 
 and intension become manifested as general principles, 
 which, being briefly expressed, are known as axioms. And 
 lastly, when the system is completed, and its modes of 
 functioning postulated, it is available for the demonstra- 
 tion of many truths which were not discovered during its 
 inductive formation : for this simple reason, that the colli- 
 gation of a small number of cognate facts is sufficient to 
 enable Us to frame subaltern genera ; and it is, therefore, 
 
256 IDEAL FORMS OF NATURAL POWERS 
 
 possible by the inverse method of deduction to demon- 
 strate those which had not been previously observed. In 
 a sense, the a posteriori gathering together and arranging 
 by induction may be called a progression from the known 
 to the unknown ; but the a priori extension of knowledge 
 by deduction is more especially entitled to this attribute : 
 for when once a science is perfectly established, it opens 
 up boundless regions of truths ; as witness the develop- 
 ments of the mathematics. 
 
 The transcendental logic of Kant has the pure abstract 
 character which we have ascribed to it ; for it is free from 
 all special materials, and from every element of an empi- 
 rical nature : it seeks to discover the a priori principles 
 of the understanding ; neglecting all derived and complex 
 conceptions, it fixes its attention solely on the pure logical 
 concepts. But Kant has confused his subject by mixing 
 it up with the consideration of the mental faculties con- 
 cerned in the production of pure concepts ; phenomena 
 which belong to psychology, and which have no concern 
 with logic. It is curious that Cousin *, in commenting on 
 this logic of Kant, whilst admitting the certainty of its 
 a priori truths which within these limits make it an in- 
 fallible science, remarks that et it is entirely void, having 
 no relation to reality ; and subject to such inherent weak- 
 ness, that it can neither assure us of external reality, nor 
 even the reality of our own proper personality," The 
 same objections might be brought against any branch of the 
 mathematics : it is strange that a science should be ex- 
 pected to explain subjects with which it has no concern. 
 
 * Lectures on the Philosophy of Kant, p. 76. 
 
MANIFEST THE REASON IN NATURE. 257 
 
 This shows, we think, that the character of logic is not 
 rightly apprehended. Some modern writers have described 
 this science as the geometry of thought ; because the 
 methods of the mathematics are so conspicuously logical : 
 but, in truth, it is geometry which is the logic of space ; 
 for abstract .its special content) universal extension, and its 
 particular figurate magnitudes, that is its subject-matter 
 or noun-substantive, and all that then remains is its rational 
 form, which is logic. 
 
 Our definition of logic, that it is the knowledge of pure 
 abstract system, the systematic knowledge of abstract 
 ideas, or in short that it is science, accords very well with 
 the opinion of Aristotle ; in whose logic the principle of 
 classification performs a prominent part. Mr. John S. 
 Mill, in his work on logic, dwells long on this topic, and 
 condemns in no measured terms the doctrine of the Sta- 
 gyrite, as effete and valueless : as fs a principle of reason- 
 ing suited to a system of metaphysics, once indeed 
 generally received, but which for the last two centuries has 
 been considered as finally abandoned ; though there have 
 not been wanting, in our own day, attempts at its revival." 
 
 The dividing things into classes, and referring every 
 thing to its proper class is not, Mr. Mill thinks, the office 
 of logic : and the maxim that whatever can be affirmed 
 or denied of a class may be affirmed or denied of everything 
 included in the class, the celebrated dictum de omni et 
 nullo, is, he asserts, " a signal example of logical error." 
 On such a purely intellectual subject as this, is it not more 
 probable that it is Mr. Mill, and not Aristotle, who is in 
 error ? We have no desire to unfairly criticise Mr. Mill's 
 work on logic ; it is a talented production, well calculated 
 
 s 
 
258 IDEAL FORMS OF NATURAL POWERS 
 
 to promote scientific investigation , and to take a place side 
 by side with the excellent " Discourse on the Study of 
 Natural Philosophy," which indeed it greatly resembles : 
 but it has not, in our opinion, any pretension to the charac- 
 ter of a System of Logic. 
 
 A quotation will, perhaps, exonerate us from the charge 
 of misrepresentation : for it will show how concrete and 
 materialistic his notions are concerning logic, the whole 
 consent or which is pure and formal : or as some would 
 say, transcendental. " The notion," says Mr. Mill*, " that 
 what is of primary importance in a proposition, is the 
 relation between the two ideas corresponding to the sub- 
 ject and predicate (instead of the relation between the 
 two phenomena which they respectively express), seems to 
 me one of the most fatal errors ever introduced into logic. 
 The treatises of logic, produced since the intrusion of 
 this cardinal error, almost always tacitly imply that the 
 investigation of truth consists in contemplating and hand- 
 ling our ideas, or conceptions of things, instead of the 
 things themselves : a doctrine tantamount to the assertion, 
 that the only way of acquiring a knowledge of nature, is 
 to study it at second-hand, as represented in our own 
 minds." Surely in logic, we can have nothing to do with 
 the things themselves : they are not the objects with which 
 this science has any concern; if we desire knowledge 
 thereon we must go to physics, and not to logic. Mental 
 representations are certainly, in a sense, obtained at second- 
 hand ; but they do not originate in the mind by the exer- 
 cise of a fanciful imagination : they are derived from 
 
 * A System of Logic, vol. i. p. 98. 
 
MANIFEST THE REASON IN NATURE. 259 
 
 nature herself; and though not actual realities, they are the 
 rational forms of things themselves; and if rightly inter- 
 preted must correspond therewith. All nature is a dual- 
 ism of actual for ces and rational forms ; and inasmuch as 
 these are co-existent and co-equal attributes of their re- 
 spective powers, they reciprocally manifest each other, as 
 objects of knowledge: and each kind of objects may become 
 the subject of distinct sciences ; the one causal and phe- 
 nomenal, as physics, the other pure and formal, as logic : the 
 one is concerned with the real and subjective side of 
 nature ; the other with the ideal and objective. 
 
 In logic the mind is only conversant with those ideas 
 which relate to degrees of order or system : and when it 
 has become cognisant of these objects, it proceeds to 
 their denomination, definition, and classification. 
 
 In the development of logic we first accept the ideas of 
 concrete things presented by the senses, as if they were 
 the things themselves, and we denote these individual 
 things by names, which though mere mental forms, pass 
 current as th^ counterpart of the things signified; in 
 adopting such ideas, however, as logical objects, we deal 
 not with the contents of things, but only with their forms. 
 In the next place, we unite together many particular ideas, 
 differing from each other only by some trivial or accidental 
 properties, by some common bond of likeness; and thus 
 we obtain an idea of higher order, and mark its degree by 
 the name of species. By similar and analogous repetitions 
 of this process, we acquire a knowledge of many different 
 species ; and by the same routine we collect the species 
 into distinct groups, each of which has a common term of 
 agreement, and such groups are called genera or classes. 
 
 s 2 
 
260 IDEAL FORMS OF NATURAL POWERS 
 
 And in like manner we can proceed step by step, colli- 
 gating classes of the same degree into a new and higher 
 order, until at last, by successive generalisations, we 
 attain to the summum genus of the system. 
 
 Now each species or genus taken by itself, or abstracted 
 from all higher relations, is a perfect unity or universal, 
 consisting of, and capable of division into, subordinate 
 parts; for by its very constitution it only exists as an 
 aggregate of its subalterns. How many parts make up a 
 universal, is unknown, they may be a select few or a 
 great multitude ; but this one thing is certain, they must 
 all possess the same characteristic attribute. And so it 
 comes to pass, that having united particular ideas into a 
 universal, a complex idea, or proposition, is obtained ; as 
 A + B = AB, which is an identical proposition, in fact, 
 a definition, for it gives the value of either side of the 
 equation, even when converted. Or in other words, as 
 well set forth by Lord Kames*, " The essence of a thing 
 consists of these two parts ; first, what is common to it 
 with other things of the same kind ; and secondly, what 
 distinguishes it from other things of the same kind. The 
 first is called the genus of the thing, the second its specific 
 difference; a definition, therefore, must consist of these 
 two parts. To frame, therefore, a definition of any logical 
 idea, we must take the genus of the order in which it 
 stands, and the specific difference by which it is distin- 
 guished from other species of the same genus. These two 
 terms give a perfect definition." 
 
 A universal is by definition equal to all its parts ; but 
 
 * Sketches of Man, book iii. sect. 4. 
 
MANIFEST THE REASON IN NATURE.. 261 
 
 both extremes of these parts are indefinite : the smallest 
 part, or individual, can only be posited as an indefinite 
 minimum indivisible; and the totality of the known parts 
 is an indefinite maximum divisible, which approximates 
 to, but is never perfectly commensurate with the universal. 
 Since logic underlies all systematic knowledge, it therefore 
 follows that the same incertitude must belong to the 
 minima and maxima of every science : and so likewise 
 may be discerned in every science the same principles of 
 buKviduatwn, differentiation, and integration as are con- 
 cerned in the logical universal. 
 
 The universal, whether a genus or a summum genus, is 
 a diversity in unity, which comprehends all its particular 
 ideas; and the infima species in its relations to all the 
 generic characteristics of the system possesses all their 
 attributes, together with something peculiarly its own ; 
 or as otherwise expressed by Thomson *, " in the summum 
 genus the intension is least, the extension greatest ; in the 
 infima species the intension is greatest, and the extension 
 least." That is, the attributes of the constituent parts of 
 the system are in an inverse ratio towards each other in 
 the opposite extremes of the universal. From this it is 
 evident that what is called quantity in logic is a definite 
 degree of comprehension ; the different quantities of ideas 
 have reference to the extent of their signification, which 
 depends on their position in the system. And quality in 
 logic is the similarity or dissimilarity of ideas in respect to 
 a certain term of comparison ; and the possession or not 
 of such quality makes them a member of, or excludes them 
 
 * Laws of Thought, p. 104. 
 s 3 
 
262 IDEAL FORMS OF NATURAL POWERS 
 
 from a given class. Whenever such a similarity is affirmed 
 or denied, the statement of such a comparison of ideas is 
 called a categorical proposition ; such a proposition may 
 be a simple expression, as in a definition, or it may be a 
 complex statement comprising an involution of many ideas, 
 which, however, must be reducible into, or accord with the 
 regular formula. The ideas of which a proposition is com- 
 posed are called its terms ; the term affirmed or denied is 
 the predicate, and that of which the predicate is affirmed or 
 denied is the subject of the proposition. If the predicate 
 affects the whole of the subject, the proposition is universal, 
 if only a part of the subject, then it is a particular propo- 
 sition ; and so the proposition is said to be an affirmative 
 or negative proposition, according to the character of the 
 predicate. There are, therefore, four distinct kinds of 
 propositions, the universal and the particular affirmative, 
 and the universal and particular negative : as was clearly 
 pointed out by Aristotle ; and which we now see to accord 
 well with the essential constitution of ideas, the interpreted 
 forms of realities. 
 
 Attempts have been made to enlarge this number of 
 propositions, but in vain : for singular and indefinite pro- 
 positions are inconsistent with the nature of the logical 
 system. A singular proposition, not having a general, but 
 an individual term for its subject, is as the particular of 
 an infima species, or the ultimate part of some whole, in- 
 capable, like all other units, of farther resolution ; so that, 
 if we predicate of it, it must be as an indivisible oneness. 
 Again, an indefinite proposition is that whose subject has 
 neither a universal nor a particular signification ; a par- 
 ticular quantity, however, may be understood, but this is 
 
MANIFEST THE REASON IN NATURE. 263 
 
 the only indefinite. Both these kinds of propositions arc 
 therefore superfluous ; and indeed the four cardinal ones 
 are capable of including all statements that are logically 
 necessary. 
 
 Having thus briefly noticed a few of the leading topics 
 of logic, there remains to say a few words about its axioms 
 and postulates. As regards its axioms, or principles, they 
 are the expressions of those fundamental relations which 
 subsist between ideas, as parts of a system : they have, like 
 the axioms of all other sciences, the form of self-evident 
 truths ; and on this account have been often undervalued. 
 It is an axiom of logic, that a universal comprises all its par- 
 ticulars : for it is evident that in a classified arrangement, 
 as loag as division and subdivision can be carried on, all 
 the parts resulting therefrom cannot exceed, or fall short 
 of the whole. It is indeed but another mode of express- 
 ing the principle of classification ; that a summum genus 
 contains all its ordinated subalterns : and this principle is 
 no other than that of logic itself: and so it comes to pass 
 that logic being the universal basis of all the sciences, its 
 principle is carried over to these ; as we see its equivalent 
 in the axiom of geometry, " the whole is equal to all its 
 parts." Again, the axiom that, terms which agree with a 
 third term, agree with one another, is but another expression 
 for one of the principles of classification ; viz., that things 
 which are connoted by a common mark, are species of the 
 same genus. And simple as this axiom is, it forms the 
 basis of the syllogism, which, in all its legitimate moods, 
 uses a middle term for ascertaining the relations of the 
 major and minor terms. In short, logical axioms are the 
 general expressions of principles, which have been evolved 
 
 s 4 
 
264 IDEAL FOKMS OF NATURAL POWERS 
 
 from, and are immediately connected with the very essence 
 of systematic order. 
 
 Passing on then from definitions and axioms, it only 
 remains to consider the logical postulates. The former 
 relate to the knowledge of ideas as passive mental objects, 
 or forms of reason ; but the latter relate to the results, or 
 conclusions evolved by the mental energy acting thereon, 
 according to the laws of thought ; a process by which the 
 unknown become known, an important means for the ad- 
 vancement of knowledge. The modus operandi in this 
 process, that is, the logical methods, are capable of being 
 understood ; but how the conscious faculty practically per- 
 forms them we cannot tell ; we therefore assume the pos- 
 sibility, and provisionally postulate that which cannot be 
 demonstrated. The postulates of logic are, that the mind 
 can so deal with ideas as to construct them into inductive 
 and deductive propositions ; that it can manipulate know- 
 ledge both synthetically and analytically : these are func- 
 tions of the logical mind, and we acknowledge them as 
 such ; but we can no more expla n how the mind per- 
 forms them, than we can how it perceives ideas; and, 
 mediately through them, the forms of things, the reason in 
 Nature. 
 
 Induction deals with various terms, which it combines 
 together into propositions ; and these again into others of 
 a higher generalisation ; until it arrives at the most com- 
 prehensive proposition, which becomes the definition of the 
 science. At any stage of this development, deduction 
 may be employed by a reverse mode of operation ; un- 
 folding particulars, even such as were before unknown, 
 from the general propositions. This latter process con- 
 
MANIFEST THE REASON IN NATURE. 265 
 
 stitutes that of the syllogism : it consists of three, and only 
 three propositions ; viz. the major premiss, the minor 
 premiss, and the conclusion. In the last- mentioned pro- 
 position, the subject is called the minor term, the predicate 
 the major term : in the major and minor premises of the 
 syllogism, the corresponding terms are compared with a 
 common middle term, in order to judge of their agreement 
 or disagreement ; and on this account it was called by the 
 older logicians the argument. 
 
 It has already been stated, that there are four kinds of 
 propositions ; and since there are three kinds also in each 
 syllogism, all the possible ways of combining the four 
 cardinal ones, (symbolised by A, E, I, O,) by threes, are 
 sixty-four : but of these numerous moods but a small num- 
 ber are practically employed. The figure of a syllogism 
 consists in the situation of the middle term with respect 
 to the two extremes of the conclusion. Four kinds of 
 figures have been described, but it is by many admitted 
 that there are only three which are legitimate: and of 
 these the first figure, in which the middle term is made 
 the subject of the major premiss, and the predicate of the 
 minor premiss, is by far the most definite ; and to which 
 Aristotle's dictum is immediately applicable. All valid 
 arguments whatever may be reduced to one or other of 
 these three figures ; and probably even to the first alone, 
 by aid of legitimate conversions. 
 
 Before quitting the subject of logic, there are some 
 other matters connected therewith, which must not be 
 passed over without remark. 
 
 The quantification of the predicate, which has been 
 ably advocated by Sir. W. Hamilton and De Morgan, is 
 
266 IDEAL FORMS OF NATURAL POWERS 
 
 virtually excluded from logic according to our view of its 
 constitution : for unless we have greatly erred, logic is a 
 pure formal science ; capable, indeed, of application to other 
 subjects, but in its own peculiar sphere it givea results of 
 great certitude, like the mathematics. Hypothetical, con- 
 ditional, and disjunctive syllogisms, are only tentative 
 processes : the data deal only with probabilities ; so that 
 positive conclusions cannot be obtained. And so it follows 
 that if we deal with such indistinct and indefinite data as 
 the toto-partial, and the parti-partial negatives, we cannot 
 expect to arrive at any decisive results. Such an in ex- 
 clusive quantification of the predicate does not add to our 
 knowledge ; for to say that some individual idea is not 
 some other individual idea of the same kind, is merely 
 asserting that particulars of a universal are not identical; 
 which indeed the very signification of the systematic term 
 implies. Take, for example, any species, say man ; and 
 then to say that some individual, or this man, is not some 
 other individual, or that man, would be making an un- 
 necessary assertion; and surely such a parti-partial negation 
 could furnish no datum for a syllogism: and if by any 
 ingenuity it could be so employed, it would be a work of 
 supererogation ; for simple perception, or a knowledge of 
 the meaning of the words used, would furnish all the neces- 
 sary information. On this subject, Mr. William Thomson* 
 remarks, " that in a list of conceivable modes of predication, 
 the toto-partial and the parti-partial negatives are en- 
 titled to a place : " we cannot concede even thus much, 
 for in a pure science we have nothing to do with the 
 
 * Outlines of the Laws of Thought, p. 179. 
 
MANIFEST THE REASON IN NATURE. 267 
 
 possible, or the probable, but only with positive principles. 
 Though not agreeing with him, in his deference of opinion 
 to so high an authority, yet we accept his own deli- 
 berate opinion, that " a parti-partial judgment is spurious 
 upon two grounds : it denies nothing, because it does not 
 prevent any of the modes of affirmation ; it decides nothing, 
 inasmuch as its truth is pre-supposed, with reference to 
 any pair of conceptions whatever." 
 
 All the figures of the syllogism have been symbolised 
 by various schemes of notation : the most recent, and pro- 
 bably the best, is that of Sir W. Hamilton. It is not 
 improbable that logic may hereafter be successfully treated 
 by symbols, as in the case of algebra : for since its princi- 
 ples are so few and abstract, it ought to be practicable. 
 Professor Boole has indeed published, a few years ago, an 
 elaborate work on this subject; more particularly in re- 
 ference to the theory of Probabilities: this we do not 
 regard as a part of logic ; though it is a subject to which 
 this science, in common with the calculus, may be applied. 
 He has not, we think, clearly apprehended and formulated 
 the principles with which he commences ; and of course 
 the validity of the whole superstructure depends thereon : 
 it is therefore requisite to state our reasons for arriving at 
 this conclusion. 
 
 We have already given the formula A + B = AB, as 
 illustrating the constitution of an idea, of a proposition, 
 and indeed of any universal, whether real or ideal. Per- 
 haps as the compound AB is not a mere cumulation of its 
 constituents, but an actual union endowed with distinctive 
 properties, it might have been more correct to have written 
 A 4- B = C : but this does not indicate its composition, 
 
268 IDEAL FORMS OF NATURAL POWERS 
 
 which in many cases, especially when the constituents vary 
 in their relative proportions, is very desirable. A still 
 greater objection may be made to it on account of its ex- 
 pression being different from that in mathematical usage ; 
 but of this hereafter. 
 
 De Morgan * objects to the formula A + B = AB, as 
 " confounding the ideas of cumulation and combination : 
 and thinks that the mathematician would stare at an equa- 
 tion 2 + 2 + addition = 4." It certainly would be mon- 
 strous : but for what reason the third particular, -f addi- 
 tion, is introduced, we cannot tell ; for it is already 
 satisfied by the plus symbol between the numerals. The 
 sum, 4, is not a mere cumulation of 2 and 2 ; nor is water, 
 as he seems to imply, a simple juxtaposition of oxygen and 
 hydrogen : for they are severally a resulting compound, a 
 tertium quid, very different in properties from either of 
 their constituents. 
 
 In the construction of his logical notation, Professor 
 Boole * commences by proposing " to represent the class 
 of individuals, to which a particular name is applicable, by 
 a single letter as x: and to extend the meaning of the 
 term so as to denote even a single individual of a class." 
 This is objectionable, for although the characteristic mark 
 of any universal or class is possessed by each and all of its 
 members, it cannot be used to represent a single indi- 
 vidual of the class : if we find such a mark in an individual, 
 it determines the class ; but it will not denote the indi- 
 vidual ; this can only be done by appending to the class- 
 
 * Formal Logic, p. 49. 
 
 t An Investigation of the Laws of Thought, p. 28, et seq. 
 
MANIFEST THE REASON IN NATURE. 269 
 
 mark some discriminating particular. Every whole is 
 indeed made up of lesser parts of the same kind ; but these 
 subordinates can only be distinguished from each other, 
 as individuals, by special marks denoting their differences. 
 In continuation the Professor observes, " If an adjective 
 good is employed as a term of description, let it be repre- 
 sented by a letter, as y, which comprehends all things to 
 which the description good is applicable; i.e. all good 
 things, or the class of good things. Let it farther be agreed 
 that by the combination xy shall be understood that class 
 of things to which the names or descriptions represented 
 by x and y are simultaneously applicable." Concerning 
 this mode of notation he adds, " It is not affirmed that the 
 process of multiplication in algebra possesses in itself any 
 analogy with that process of logical combination which xy 
 has been made to represent; but only that if the arithme- 
 tical and the logical process are expressed in the same 
 manner, their symbolical expressions will be subject to the 
 same formal law." Again, " The expressions xy and yx 
 equally represent that class of things to which their 
 several members apply : hence we have xy yx" This 
 is advanced as the expression of the first law or logical 
 principle : " which may be characterised by saying that 
 the literal symbols are commutative, like the symbols of 
 algebra. This reminds us of Fichte's psychological prin- 
 ciple, ego = ego : and it is evidently inconsistent with the 
 character of a class ; for whether a class be simple as x or 
 complex as xy^ it is an entire whole, or universal, of that 
 kind of things. In the case of individual things which 
 have any one property in common, you may make such an 
 equation ; as, a pound of this is equal to a pound of that 
 
270 IDEAL FORMS OF NATURAL POWERS 
 
 in weight ; or, a yard of this is equal to a yard of that in 
 length : but to say that the same kind of pound or yard is 
 a pound or a yard, is a superfluous and unnecessary asser- 
 tion. 
 
 In his method of evolving his second logical principle, 
 he follows a process which seems to us very inconclusive. 
 " As the combination of two literal symbols in the form 
 xy expresses the whole of that class of objects to which 
 the names or qualities represented by x and y are together 
 applicable ; it follows, that if the two symbols have ex- 
 actly the same signification, their combination expresses 
 no more than either of the symbols taken alone would do. 
 In such a case, we should therefore have x y = x. As y 
 is however supposed to have the same meaning as x, we 
 may replace it in the above equation by x ; and we thus 
 get x x x ; or # 2 = x: which is, in fact, the expression 
 of a second general law of those symbols, by which names, 
 qualities, and descriptions are symbolically represented." 
 This algebraical reasoning is correct as to form, but the 
 assumed data are irrational, and therefore do not give a 
 legitimate conclusion ; the two symbols have not the same 
 signification : take the things signified as pure abstract ideas 
 of classes, still they are different and distinct classes, and 
 therefore cannot be commutative. If we take the concrete 
 ideas of the class sheep, and of the class white, which are 
 adduced in illustration, it is perfectly unimaginable to con- 
 ceive that the combination white sheep, expresses no more 
 than sheep, or white taken alone would do ; or that sheep 
 and white have exactly the same signification, in direct 
 contradiction to their respective definitions, and to the 
 previous assumption, that sheep and white are distinct 
 
MANIFEST THE REASON IN NATURE. 271 
 
 classes of things, and therefore represented by diverse 
 symbols x and y. 
 
 " The symbols of logic," he says, are " subject to the 
 special law x z =x. Now of the symbols of number there 
 are but two, viz. and 1, which are subject to the same 
 formal law. We know that 2 =0, and that 1 2 =1 ; and 
 the equation #*=#, considered as algebraic, has no other 
 roots than and 1 . Let us conceive, then, of an Algebra 
 in which the symbols x, y, z. &c., admit indifferently of 
 the values and 1, and of these values alone. The laws, 
 the axioms, and the processes of such an algebra will be 
 identical in their whole extent with the laws, the axioms, 
 and the processes of an algebra of logic. Difference of in- 
 terpretation will alone divide them." Upon this principle 
 the method in the " Investigation of the Laws of Thought " 
 is established. 
 
 But what, if our remarks above, on the evolution of the 
 special law x 2 =x, have any foundation in truth; what 
 then will become of the principle on which this formal 
 logic is based ? The data being invalid, the superstruc- 
 ture cannot stand. We doubt very much the propriety of 
 introducing the symbols of number, and 1, into the for- 
 mulae of logic : the signs + , , and = , are quite legiti- 
 mate ; they are purely abstract and universal, and may be 
 used in connection with a science so perfectly formal as 
 logic ; but and 1 are numerals, and belong to arithmetic. 
 If the symbol x represents in logic a particular class, such 
 a symbol can undergo no other variations than are com- 
 patible with the notion of a class : whether this class be 
 a universal or a genus, or whatever its degree of rank, it 
 cannot be raised to any higher power by duplication ; its 
 
272 IDEAL FORMS OF NATURAL POWERS. 
 
 attributes are not those of quantity, as in the case of 
 numbers. A class is a whole, and it is indeed so far 
 analogous to an integer number, that it can be divided and 
 subdivided into many fractional parts ; but as each particu- 
 lar class has not its like in the universe, as it is one indi- 
 vidual thing, like a unit in arithmetic, it cannot function 
 by multiplication. 
 
 Though disagreeing with Professor Boole concerning 
 the formation of logical principles and their notation, we 
 think that he has initiated a useful undertaking in his re- 
 commendation of the employment of symbols for the illus- 
 tration of the processes of logic ; and in our remarks on 
 his work, it was only intended thereby to use it as a text, 
 whereby our own views might be more clearly unfolded. 
 
 To sum up in a few words the result of our inquiry con- 
 cerning logic, it may be stated, that it is science or 
 systematic knowledge ; that is, a knowledge of all abstract 
 ideas relating to degrees of order, or system: and since 
 such ideas are only obtained by the interpretation of- the 
 relations of bodies in the system of nature, in respect to 
 their ranks in the hierarchy, the idea of order might have 
 been adopted as the noun -substantive of logic, the science 
 of order implying a systematic knowledge of order. 
 
273 
 
 CHAP. X. 
 
 THE FORMAL SCIENCES, THE KNOWLEDGE OF IDEAL 
 SYSTEMS. 
 
 The Mathematics Sciences of Number, Space, and Time Regarded 
 as the Basis of all the Sciences ; but this Character belongs to 
 Logic. The early Origin of the Abstract Sciences. Arithmetic, 
 the Science or Logic of Number. Geometry, the Science or 
 Logic of Space. These Sciences might have been immediately 
 derived from Logic. What is Space? The Real and Ideal can 
 only exist by and in each other. Space not a Vacuum, but a. Plenum ; 
 the Form of the real Content gives the Idea of Space. Space an in- 
 definite Maximum, not an Infinite. The Subject of Geometry is 
 universal Extension, and all particular or subordinate Parts of Ex- 
 tension. Of Space and partial Spaces. What is Time? Various 
 Conjectures thereon. No beginning and no ending of Time; but a 
 continuous flowing onwards. All Events occur in Time. Time 
 goes on whether Anything happens or not. Time one of the ex- 
 trinsic Relations of Existence Conceivable only as an indefinite 
 Past, Present, and Future. The formal Succession of Events gives 
 the Idea of Time. The Analogies between Space and Time. 
 What is the Science of Time? Not Rational Mechanics, nor 
 Rational Arithmetic ; but a special Science, Chronornetry. Con- 
 clusion. 
 
 LOGIC is par excellence Science; the summum genus of 
 knowledge, which only needs the adjunct of some differ- 
 ential idea, in order to constitute a specific science : 
 such differential ideas, if pure abstractions, as those of 
 number, space, and time, give sciences which are universal, 
 inasmuch as their subjects in general apply to all natural 
 
 T 
 
274 THE PURE FOEMAL SCIENCES, 
 
 phenomena; and which sciences, being well adapted as 
 preliminary disciplines, have been called the mathematics. 
 
 The abstractions, on which the mathematical sciences 
 rest, are fundamental principles, or noun-substantives, 
 arrived at by the contemplation of natural objects : but 
 although our knowledge of them has been arrived at a 
 posteriori, there can be little doubt that the rational forms 
 previously existed, as the reason in nature, before they 
 were interpreted by us as universal and necessary truths. 
 It was not possible for us to know these truths a priori by 
 a species of intellectual intuition ; indeed it yet remains 
 to prove that we possess such a faculty : but when once 
 they have been logically evolved from concrete ideas, we 
 can then trace their germs in the universal system of ideas, 
 as clearly as in the system of natural realities ; so that 
 from the principles of logic alone it might be possible to 
 obtain them by an a priori process ; as we will endeavour 
 to show in the sequel. 
 
 It must not, however, be kept out of sight that our 
 notion of logic is not that which ordinarily prevails. *' The 
 mathematics," says Comte,* " by itself in its abstract purity, 
 signifies science : the Greeks had no other, and we may 
 call it the science ; for its definition is neither more nor 
 less (if we omit the specific notion of magnitudes) than 
 the definition of all science whatsoever; for all science 
 consists in the co-ordination of facts." Again, " The ab- 
 stract portion of the mathematics is the only one which 
 is purely instrumental, it being simply an immense exten- 
 sion of natural logic to a certain order of deductions." 
 
 * Positive Philosophy, vol. i. p. 39. 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 275 
 
 These statements confirm our assumption that logic is the 
 science : for abstract the specific notion of magnitudes 
 from the mathematics, and there remains only logic, the 
 knowledge of systematic ideas. In another place, how- 
 ever, Comte has defined the object of the mathematics to 
 be the indirect measurement of magnitudes ; or, to deter- 
 mine magnitudes by each other, according to the precise 
 relations which exist between them : it is evident that if 
 the idea of magnitude be omitted from these definitions, 
 there is no objective content, and therefore there can be 
 no relations; but on our view, there remains a content in 
 the idea of systematic order. 
 
 It is a curious circumstance, that the most abstract 
 sciences are those which were first constructed : thus logic, 
 arithmetic, and geometry were known to the ancients, but 
 not, chronologically, in their rational order; whilst the 
 natural or concrete sciences are the discoveries of modern 
 times. In the contemplation of nature, it must, at a very 
 early period, have struck the observer, that its objects 
 were of different kinds, very numerous, and greatly diver- 
 sified both in size and figure : but it was long before these 
 conceptions were distinguished by the general and abstract 
 names of classes, multitudes, and magnitudes ; and still 
 longer before, by abstraction, the ideas of order, number, 
 and space were determined, and posited as universals, the 
 noun-substantives of the mathematics. We have already 
 dwelt at some length on logic; and we now proceed to 
 make a few remarks on the sciences of number and space : 
 many novel observations thereon cannot be expected. 
 
 The summum genus of arithmetic is the universal, the 
 sum total or totality of all particular integral numbers, and 
 
 T 2 
 
276 THE PURE FORMAL SCIENCES, 
 
 their respective fractions : and the knowledge of this 
 universal is the science or logic of number. So that the 
 idea of arithmetic, when analysed, gives a numeral content 
 and a logical form; and when it functions, it is the subjec- 
 tive logical mind which operates on the objective numbers, 
 according to its rational laws : generalising, in one direc- 
 tion, by the inductive method, until all the enumerations 
 of the system have been completed ; and effecting calcula- 
 tions in another direction by deduction, a process of 
 ratioing, by which the relative value of particular sums is 
 demonstrated. The latter method is the ultimate object 
 of the science ; the results of its operations are called cal- 
 culations ; and when used we are said to calculate. We 
 have remarked, that the mathematics might possibly have 
 been derived a priori from logic, independent of the sys- 
 tem of natural realities ; and in the first place we will 
 endeavour to show how this holds good in the case of 
 arithmetic : when naturally derived, it takes place by the 
 abstraction of the idea of numbers from the multitude of 
 surrounding objects ; but when logically derived, it is by 
 observing the process of synthesis, by which idea is added 
 to idea, until the entire system of ideas is constructed. A 
 system or classified universal, is a diversity in unity, con- 
 sisting of many subordinate degrees of order, all rising 
 one above another in value : and the contemplation of 
 such a whole and of its parts varying from each other by 
 regular increments, might have suggested the idea of num- 
 ber, as readily as the multitudes of natural objects : and 
 this idea once secured, the process of enumeration would 
 soon follow ; for as the individual is the minimum degree 
 of order, so is the unit that of number ; and as the species 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 277 
 
 consists of many similar individuals, so each digit is com- 
 posed of a definite number of units ; and so on. Likewise 
 in the case of geometry, the logical universal gives the 
 idea of the greatest comprehension containing the whole 
 array of subordinate ideas ; whilst the limits of each in- 
 ferior subaltern become successively more and more con- 
 tracted in respect to the extent of their application : and 
 this idea of limitation, the variation of extension from the 
 highest to the lowest degree of order, is very near akin to 
 the notion of expanse or extension of space. But it must 
 be confessed that knowledge obtained on the realistic side, 
 by noting the dimensions and figures of natural bodies, is 
 a more satisfactory foundation for geometry. 
 
 The particular objects of which geometry treats, are the 
 limited forms or figurate magnitudes of space. Now space in 
 its totality, or universal space, is the expanse or extended 
 form of the universe, mentally abstracted from all the 
 material contents, or realities, of the system of nature : and 
 if universal space be only an abstract, or formal exten- 
 sion, all particular spaces must partake of the same cha- 
 racter ; and thus we conceive of them as breadthless lines, 
 depthless surfaces, and voluminous figures, void of all 
 material content. " By the character of our mind," re- 
 marks Comte*, (< we are able to think of the dimensions and 
 figures of a body in an abstract way ; and we thus obtain 
 an idea of space. This abstraction is now familiar to us ; 
 and we cannot conceive of any space, filled by any object, 
 which has not at once volume, surface, and line." 
 
 Tt is usual to speak of space as something sui generis, 
 
 * Positive Philosophy, vol. i. p. 87. 
 
 T 3 
 
278 THE PUKE FORMAL SCIENCES, 
 
 actually existing ; a something, or rather a somewhere, in 
 which bodies have been placed ; it is admitted that bodies 
 are, chronologically, before space in the order of thought ; 
 because we can only conceive of space as the place occupied 
 by bodies ; yet logically it is supposed to be prior, as a 
 place provided for the reception of created bodies. We 
 are disposed to reject this interpretation in toto, as inconsis- 
 tent with the constitution of the universe. Space is, to 
 us, not an actuality per se, nor is it a mere capacity for re- 
 ceiving bodies about to be called into existence : it is only 
 the form, the abstract plan or design, of natural bodies, 
 which their forces assume under the influence of their in- 
 nate rational laws ; the real and ideal being co-existent 
 and inseparable, and only capable of existing by and in 
 each other. Space, then, has no actual existence apart 
 from bodies ; it is only the modal forms of their extension ; 
 we may logically insulate these forms by abstraction, and 
 call them spaces, and the totality of such space, universal 
 space ; and thus these abstract ideas may become the 
 objects of knowledge. 
 
 This view of the subject will not, of course, be accept- 
 able to those who regard interstellar space, in which celestial 
 bodies are contained, as void of all content : but if it be 
 admitted, as there is every reason to believe, that space is 
 not a vacuum but a plenum of a material fluid, or ether ; 
 then, it is not so difficult to conceive, that it is the idea 
 which arises in our mind of the extended form of univer- 
 sal existence which constitutes space. 
 
 There is yet another point concerning space, in which we 
 are not in accord with the general opinion. Space is not 
 only spoken of as infinite, which in its mathematical sense 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 279 
 
 seems rather to mean indefinite, but also as absolute : we 
 proceed to give our reasons for thinking both these terms 
 objectionable. 
 
 "Space," observes W he well*, "is not indeed an ob- 
 ject of which we perceive the properties, but a form of 
 our perception ; not a thing which affects our senses, but 
 an idea to which we conform the impressions of sense." 
 This we accept as sound doctrine ; but we cannot assent 
 to the following. " When we speak of spaces, we under- 
 stand by the expression, parts of the one and the same 
 identical everywhere extended space. We conceive a 
 universal space, which is not made up of these partial 
 spaces, as its component parts, for it would remain if 
 these were taken away ; and these cannot be conceived 
 without presupposing absolute space." This statement 
 seems to involve a contradiction : in one place it affirms 
 that spaces are parts of one and the same space ; and in 
 another, that universal space is not made up of partial 
 spaces, for it would remain if these were taken away. 
 This is so inconsistent with the maxims, " that a thing can- 
 not be, and not be, at one and the same time; " and "that the 
 whole is equal to all its parts," that we cannot but suspect 
 some inadvertence has occurred in the statement. If par- 
 ticular spaces are parts of one and the same space, the lat- 
 ter is necessarily a logical universal ; that is, a genus made 
 up of species : now take away the species, and the genus 
 must be annihilated; for the parts make up the whole. 
 As we view the subject there can be no annihilation ; but 
 it may be objected, that spaces are pure ideal forms, or 
 
 * Philosophy of the Inductive Sciences, book ii. chap. iii. 
 T 4 
 
280 THE PURE FORMAL SCIENCES, 
 
 abstractions, the mere creations of the mind, and must not 
 therefore be conceived of as actual existences : we answer, 
 that in the case of forces a perfect conservation is admitted ; 
 and forces and their correlative forms are indissolubly 
 conjoined in actual realities, or natural beings ; if you can 
 take away any partial spaces from universal space, you 
 must at the same time annihilate some portion of natural 
 bodies ; for the universe of forces, and the universe of 
 rational forms conjoined, make up the natural universe or 
 system of nature. We can, indeed, conceive of universal 
 space, as a whole, apart from its subordinate parts, and 
 connote it by the generic attribute of extension ; and we 
 can conceive of its parts, as all possessing this common 
 attribute, and something more, which make them specific 
 objects of knowledge : but we cannot conceive any of 
 these parts taken away, and yet that universal space would 
 remain intact. 
 
 f( Absolute space," continues our author, t( is essentially 
 one : and the complication which exists in it, and the con- 
 ception of various spaces, depends merely upon boundaries. 
 Space must, therefore, be not a general conception ab- 
 stracted from particulars, but a universal mode of repre- 
 sentation, altogether independent of experience. Space is 
 infinite. We represent it to ourselves as an infinitely 
 great magnitude. When we say that all bodies and par- 
 ticular spaces exist in infinite space, we use an expression 
 which is not applied, in the same sense, to any cases ex- 
 cept those of space and time." Now what has been said 
 concerning space as a universal, shows that it cannot be an 
 absolute in its usual metaphysical sense : for it is made up 
 of particulars ; and an absolute has no such relations. We 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 281 
 
 do not think that such an idea is very applicable to space, 
 which is the formal extension of finite and conditioned 
 existences. Lastly, concerning partial spaces our author 
 remarks, " As space limited by boundaries gives rise to 
 various conceptions of form Qvjigure, every possible form 
 of line, straight line and curve, and of curves an endless 
 number, circles, parabolas, hyperbolas, spiral helices; and 
 plane surfaces of various shapes, parallelograms, polygons, 
 ellipses ; and solid figures, cubes, cones, cylinders, spheres, 
 spheroids, and so on : all these figures have their various 
 properties, depending on the relations of their boundaries ; 
 and the investigation of their properties forms the business 
 of the science of geometry." 
 
 "Instead of adopting," says Cointe*, "the inadequate 
 account of geometry, that it is the science of extension, I am 
 disposed to give, as a general description of it, that it is the 
 science of the measurement of extension. Even this does 
 not include all the operations of geometry, for there are 
 many investigations which have not for their object the 
 measurement of extension. But regarding the science in 
 its leading questions as a whole, we may accurately say 
 that the measurement of lines, of surfaces, and of volumes, 
 is the invariable aim, sometimes direct, though oftener in- 
 direct, of geometrical labours." 
 
 The definition of geometry as the science of space is 
 simpler, and we think preferable : for the idea of space 
 includes everything relating to extension, all varieties 
 of figures ; and all these spaces may be dealt with, both in- 
 ductively and deductively ; and when by the latter process 
 
 * Positive Philosophy, vol. i. p. 86. 
 
282 THE PUKE FORMAL SCIENCES, 
 
 their ratios are determined, it is called mensuration. It is 
 not necessary to mention these circumstances in a defini- 
 tion of the science ; for the very fact of its being a science 
 implies all this : for every science has a phenomenal and a 
 causal aspect, under each of which the subject-matter of 
 the science must be considered. 
 
 The definitions, postulates, and axioms of geometry are so 
 well developed, and so generally known, that we need not 
 dwell thereon ; the few remarks which we have to make, 
 not being a proficient in the mathematics, require some 
 apology. But the very fact of this deficiency is perhaps 
 no disqualification for such an undertaking ; because an 
 accomplished geometrician would be amongst the last to 
 call in question, and discuss the principles of his science : 
 he has received them, as established data, and found them 
 adequate for all his purposes; and therefore he does not 
 concern himself with their origin or filiations. But our 
 attention being more particularly directed to such subjects, 
 we notice, in comparing geometry with other sciences, that 
 there are some points, more particularly those relating to 
 the totality and unit of extension, the maximum and mini- 
 mum of space, which require consideration. 
 
 Universal space comprises within itself all particular 
 spaces; it is the system which is equivalent to all its 
 parts, and therefore it must be co-extensive with the 
 whole field of geometry : we, perhaps, lay undue stress 
 upon this point; but if the definition of geometry, as 
 the science of space, be correct, it is requisite that more 
 particular allusion should be made to the fundamental 
 idea of space, than is done in works on this science. 
 Space in its totality is, like all other universals, indefinite 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 283 
 
 in quantity : all we know of it is, that it is a maximum, 
 including all ideas relating to space ; and all that we can 
 predicate of the minimum of space is, that it is an indefi- 
 nite, but indivisible unit. The extremes of all universals 
 are beyond the limits of our knowledge ; this character 
 of the maximum seems to be the source of our idea con- 
 cerning a limit, a near approximation to a given integer, 
 but in no instance a perfect integration. It is a curious 
 coincidence that, when we endeavour to form some notion 
 of the figure of universal space, with common consent 
 we imngine it to be that of a sphere ; and the sphere 
 of all figures is that which will not admit of absolutely 
 precise measurement; and therefore we are obliged to 
 rest content, in both cases, with the axiom that " what 
 is true up to the limit is true at the limit." 
 
 The indefinite minimum or unit of space is called a 
 point. A point, say geometers, has no dimensions; we 
 maintain that it has, though inappreciably and indefinitely 
 small. According to Euclid, a point is that which has no 
 parts or which has no magnitude: but Dr. Simpson has 
 proposed to substitute for this definition, a point is that 
 which has position but not magnitude; objecting to the 
 definition of Euclid, that it asserts only a negative, and 
 is not convertible. But we think that Euclid's is the 
 better of the two : but both are defective, for both ignore 
 the fact that a point is a part of space, and as such, must 
 possess the generic character of the universal, which is 
 extension ; and as a matter of course, or of necessity as it 
 is termed, being a part it must have some position in the 
 whole. 
 
 A point rightly occupies a very prominent place in the 
 
284 THE PUKE FORMAL SCIENCES, 
 
 definitions of geometry ; but if we are correct in regarding 
 geometry as the science of space, the definition of space 
 as the subject-matter should have precedence of all : and 
 all that follow ought to be so expressed, as to show their 
 relations thereto. Space is the formal extension of the 
 universe. The idea of extension is the generic character 
 or noun-substantive ; and therefore all ideas relating to 
 space, all parts or species of this universal, whether large 
 or small, must have some degree of extension: so that 
 a point) which all admit has position in space, cannot 
 be devoid of extension; but as a unit of space, it must 
 have a minimum degree of magnitude with all its pro- 
 perties, though inconceivably minute. On this view, 
 we can understand how a point may have position in 
 space ; but if it has no magnitude, no extended form, 
 there can be no locus standi for it ; for a position implies 
 the appropriation of some part of space, and such is a 
 partial space for which we are contending. A point, 
 then, is not a nonentity, but a formal magnitude ; and as such 
 it may be represented in practical geometry by a definite 
 figure. These remarks may be deemed hypercritical : 
 but if rigid precision be in any case requisite, it surely 
 must be so in the definitions of a pure exact science. 
 
 For these reasons we venture to suggest the substitution 
 of the following definitions for the corresponding ones of 
 Euclid : premising ours concerning space. 
 
 Space is informal extension of the universe. 
 
 A point is a unit of space, a minimum magnitude known 
 only by its position. 
 
 A line is a continuous series of points, having only one 
 appreciable dimension, length or direction in space. 
 
TUE KNOWLEDGE OF IDEAL SYSTEMS. 285 
 
 A superficies is a partial space, a magnitude of two 
 dimensions, length and breadth. 
 
 A solid is a partial space, capable of being known in 
 all its dimensions of length, breadth, and thickness. 
 
 What we are desirous of calling attention to by these 
 remarks, is that all particulars must be related to their 
 universal : and since this universal is the systematic one- 
 ness of space (which is the ideal interpretation of the formal 
 expanse or extension of nature), the idea of magnitude, 
 unknown or known, should enter into the consideration of 
 all partial spaces. 
 
 Having advanced thus far, step by step, in the investi- 
 gation of abstract ideas of the highest generalisation, the 
 progress so far has, in some measure, proved to be satisfac- 
 tory. But the next step, though it still furnishes us with 
 an idea which holds a distinct co-ordinated position in the 
 hierarchy of ideas, involves us in some uncertainty; and 
 consequently occasions much perplexity in its treatment. 
 The idea of time is usually regarded, and frequently al- 
 luded to, as a fundamental principle, analogous to that of 
 space and of number: but its precise nature and origin, 
 and its science (for there ought to be one based on such a 
 noun-substantive), have not as yet been satisfactorily 
 determined. 
 
 What is time ? This is a question that has been as often 
 asked as What is science ? There have been many answers 
 given, but they are far from satisfactory. It has been 
 said, for instance, that time is a mode of duration, a per- 
 manence of existence, a succession of ideas, a numerical 
 sequence or rhythm, and a condition of the sensory : but 
 neither of these statements is very intelligible ; and their 
 
286 THE PURE FORMAL SCIENCES, 
 
 variety is very perplexing. According to Bishop Gleig *, 
 <f Time must be one of three things : either an ideal suc- 
 cession itself; or a certain quality inherent in all objects; 
 or lastly, the relation of co-existence between things that 
 are permanent, and the trains of fleeting ideas which suc- 
 ceed each other in the imagination." And in giving the 
 preference to the last, he states his reasons for objecting 
 to the others, as follows : " It is not the first of these, for 
 in every train of thought one idea occupies no more part 
 of time than a mathematical point occupies in space. Ten 
 thousand such points would make no part of a line ; and 
 ten thousand ideas, made to coalesce, would not give any 
 part of time. A point is a boundary of a line, but no 
 part of it : the occurrence of an idea is instantaneous ; and 
 an instant is the boundary, but no part of time. Hence 
 a train of ideas, being instantaneous, cannot constitute 
 duration or time. And secondly, that time is not a quality 
 inherent in all objects is likewise obvious ; for were ideas 
 as permanent as objects, the notion of time would never 
 have been acquired." These different views, such as they 
 are, being disposed of, there remains the accepted notion, 
 " that time is the relation of co-existence between things 
 that are permanent, and the trains of fleeting ideas which 
 succeed each other in the imagination." It is not easy to 
 know precisely what is meant by this statement. The suc- 
 cession of thoughts in the mind correspond with, and de- 
 note a series of periods of time; just the same as the 
 progress of bodies through a series of positions in space : 
 but what the relation is between a train of ideas and 
 things that are permanent, we cannot understand. 
 * Encyclo. Britan., article Metaphysics. 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 287 
 
 " Time," says Whewell*, "is not a notion obtained by 
 experience. Experience, that is, the impressions of sense 
 and the consciousness of our thoughts, gives us various 
 perceptions; and different successive perceptions consi- 
 dered together exemplify the notion of change. But this 
 very successiveness presupposes that the perceptions exist 
 in time. That things happen together, or one after an- 
 other, is intelligible only by assuming time as the condi- 
 tion under which they are presented to us. Thus time is 
 a necessary condition in the presentation of all occurrences 
 to our minds ; we can conceive time to go on, while no- 
 thing happens in it : but we cannot conceive anything to 
 happen while time does not go on. Time always is, and 
 always is present ; and even in thought we cannot form 
 the contrary supposition. Thus time is something distinct 
 from the matter or substance of our experience ; and may 
 be considered as a necessary form which the matter (ex- 
 perience of change) must assume, in order to be an object 
 of contemplation to the mind." Again, " we conceive all 
 particular times to be parts of a single and endless time : 
 and this continually flowing and endless time is what 
 offers itself to us when we contemplate any series of 
 occurrences : all actual and possible times exist as parts 
 in this original and general time. Time is infinite. All 
 limitation merely divides, and does not terminate the ex- 
 tent of absolute time. Time has no beginning and no end ; 
 but the beginning and end of every other existence takes 
 place in it." 
 
 Sir W. Hamilton f regards time as one of the extrinsic 
 
 * Philosophy of the Inductive Sciences, vol. i. p. 121. 
 f Philosophical Discussions, p. 581. 
 
288 THE PURE FORMAL ^SCIENCES, 
 
 relations of existence ; a quantity which may be considered 
 either as continuous or discrete. " Considered in itself," 
 he says, " time is positively inconceivable, if we attempt 
 to construe it in thought ; either, on the one hand, as abso- 
 lutely commencing, or absolutely terminating ; or, on the 
 other, as infinite or eternal, whether ab ante or a post: and it 
 is no less inconceivable, if we attempt to fix an absolute 
 minimum, or to follow out an infinite division. It is posi- 
 tively conceivable ; if conceived as an indefinite past, pre- 
 sent, or future : and as an indeterminate mean between 
 the two unthinkable extremes of an absolute least, and an 
 infinite divisibility ; for thus it is relative." 
 
 The foregoing quotations demonstrate a perfect analogy 
 between the ideas of time and of space. Time as a formal 
 succession is a universal idea, comprising all particulars of 
 the same character : on the principle that a whole is equal 
 to all its parts. We need not therefore dwell thereon ; 
 nor on the incompatibility of the ideas of the infinite or 
 absolute in connexion with this subject, as changing time 
 into eternity, which has no relation to the past, present, and 
 future of sublunary affairs: for what has already been 
 said of space is equally applicable to time. Since then 
 the formal extension of things furnishes the idea of space ; 
 and the formal succession of events, that of time ; we may 
 arrive at many particulars concerning time, by following 
 out its analogy to space, and of course making the 
 requisite allowances for the different character of the 
 ideas. 
 
 Thus, in space, extension is regarded as a magnitude 
 having the dimensions of length, breadth, and depth ; and 
 so in time, succession is a duration comprising the periods 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 289 
 
 of beginning, continuance, and ending. Likewise, as the 
 parts of extension are figurate magnitudes, or figures, hav- 
 ing position in space ; so the parts of succession are events 
 having occurrence in time. So particular figures in re- 
 gard to magnitude are points, lines, surfaces, and volumes ; 
 as particular events in their duration are instants, sequences, 
 and periods. And lastly, as particular figures in respect 
 to their position in space may be viewed as inferior, col- 
 lateral, and superior : so particular events in the occurrence 
 of time, are antecedent, contemporaneous, and subsequent. 
 
 Time, therefore, like space, being a universal and funda- 
 mental idea, we ought to be able to construct thereon 
 a science analogous to geometry : and such a science 
 should treat of the duration of events, as geometry does of 
 the magnitude of figures ; for diversified periods of suc- 
 cessive events make up the continuous duration which we 
 call time. Time is a universal of indefinite duration ; it 
 is the ideal expression of the total period which marks the 
 viccisitudes of the system of nature : it is an abiding con- 
 tinuance, as long as this universe lasts, just as space is a 
 limiting expanse under the same condition. Time and 
 space, therefore, as the relative forms of natural realities, 
 are possible objects of human knowledge ; but when they 
 merge into eternity and infinity, they transcend our ken, 
 for to t\\Q finite the absolute is incomprehensible. 
 
 What, then, is the science of time ? On the continent, 
 and more especially in Germany, this science is regarded 
 as identical with rational Mechanics, but the most preva- 
 lent in this country is that it is rational arithmetic. 
 " There are certain principles," says M. Cousin *, " that 
 
 * Lectures on the Philosophy of Kant, p. 52. 
 
 U 
 
290 THE PURE FORMAL SCIENCES, 
 
 are derived from our notion of time : for example, time 
 has but one dimension ; different times are successive and 
 not simultaneous. If therefore these spring from the 
 idea of time, this idea must be a pure a priori intuition ; 
 it is the foundation of our notions of change and motion, 
 which is the change of place. Now we have an entire 
 science which treats of motion ; and its propositions, like 
 those of geometry, are a priori synthetical : so that me- 
 chanical science is founded upon the idea of time, as geo- 
 metry is founded upon that of space." This reason is not 
 we think conclusive. It is indeed true that motion is one 
 kind of change, viz. that of position in space ; but it does not 
 include all kinds of changes, as for example the chemical 
 and vital: and so far from mechanical science being 
 founded on the idea of time, this idea is only concerned as 
 one of the elements in the calculation of velocities, which 
 is but one of the mechanical phenomena. 
 
 On this subject Whewell* observes, "It is clear that 
 the perception of motion, that is, change of place, pre- 
 supposes the conception of time, and is not capable of 
 being presented to the mind in any other way. If we 
 contemplate the same body as being in different places at 
 different times, and connect these observations, we have 
 the conception of motion, which thus presupposes the ne- 
 cessary conditions that existence in time implies." Time 
 is indeed an indispensable element in the consideration of 
 the velocity of motion ; it is a conception which must ne- 
 cessarily have been formed previous to the development 
 of the science of motion, for it is one of the instruments, 
 
 * Philosophy of the Inductive Sciences, vol. i. p. 123. 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 291 
 
 of which geometry and arithmetic are others, which are 
 requisite for determining the value of its phenomena ; 
 time therefore, as Whevvell says, is a necessary condition : 
 but it is not the noun-substantive of cinematics, for it is 
 not the generic characteristic, which unites all parts of the 
 science, and forms their most prominent feature. 
 
 " The relations of position and figure," says Whewell, 
 " are the substance of the science of geometry : there is 
 in like manner a science of great complexity and extent, 
 which has its foundation in the idea of time. But this 
 science, as it is usually pursued, applies only to the con- 
 ception of number, which is, as we have said, the simplest 
 result of repetition. This science is theoretical arithmetic, 
 or the speculative doctrine of the properties and relations 
 of numbers." Now this notion is, we conceive, far less 
 reasonable than that which makes the science of motion 
 and of time identical : we state our opinion freely, and 
 subject to correction ; but truth is our common object, 
 and in the pursuit of it there should be no undue de- 
 ference to authority. We therefore venture to suggest 
 that any number, or sums of numbers, can be apprehended 
 without entertaining the idea of time, or concerning our- 
 selves with the successive addition of units, by which the 
 digits and other numerals are formed. The most com- 
 plex properties of numbers are arrived at by a prolongation 
 of the rational process, similar to that which is used in the 
 formation of elementary propositions : in short, theoretical 
 arithmetic is only a higher branch of the logic of number, 
 or Arithmetic. We can note the succession of our pulse 
 and breathing, or any external succession, without concern- 
 ing ourselves about their number: but if we desire to 
 
 u 2 
 
292 THE PURE FORMAL SCIENCES, 
 
 compare any of these successions with each other, or with 
 any other known succession, in respect to their frequency, 
 then we call in the assistance of another idea, that of 
 number, and by means thereof render our knowledge more 
 definite. We might in truth mark the frequency of these 
 successions in various ways, so that by sight alone we 
 might apprehend their difference without any numeration, 
 as by several pendula vibrating at different rates : and so, 
 likewise, we know the progress of time by mere inspection 
 of the dial, without any conception of number engaging 
 the mind. It is true that in calculating, the operations 
 of the mind, like those of any other agent, are successive 
 events in time: but time continues to flow on without 
 any reference to the number of these events ; or whether 
 the mind evolves therefrom the idea of number, and by 
 means thereof proceeds to their definite enumeration. 
 Number then has no concern in the succession of events, 
 which we denote by the word time : it is itself only an 
 idea evolved from the objective form of such successions, 
 by the operation of the subjective mind; and of which 
 noun-substantive perfectly distinct from the idea of time it 
 forms the special science of number. 
 
 Time, like number, is a universal or fundamental idea : 
 it is, however, inferior to it in logical order ; for arithmetic 
 is required, as an instrument for the definite expression 
 of its phenomena ; as it does also that of space in case of 
 its geometric or figurative representations. In short, time 
 is a distinct idea sui generis, which cannot therefore be 
 identified either with the ideas of motion or of number : 
 and its science is neither that of rational mechanics, nor of 
 rational arithmetic, but is peculiar, a systematic knowledge 
 
THE KNOWLEDGE OF IDEAL SYSTEMS. 293 
 
 of its own idea. Such a science might be called chro- 
 nology, the logic of time : but this term has already been 
 appropriated to denote the knowledge of past events, the 
 history of all known times. A science of time should 
 comprise all parts of universal time; past, present, and 
 future : whatever periods of time have occurred, or may 
 occur hereafter, ought to find their positions in such a 
 system. As particular magnitudes, in geometry, have 
 definite figures which become the means of measuring 
 others, and of thus enabling us to determine unknown 
 magnitudes by those already known : so the various events, 
 which have durations of known periodicity, are made the 
 standards for determining the periods not only of past 
 events, but also of predicting, by a scientific prevision, 
 the character and duration of events yet concealed in the 
 womb of futurity. 
 
 The science of time may be called chronometry in order 
 to maintain in it the idea of measurement, which is in- 
 volved in the term geometry : such a term may perhaps 
 be confounded with the art of making chronometers ; but 
 this would be more than compensated for, by avoiding the 
 introduction of an entirely new term. Chronometry may 
 be defined the science of time, a systematic knowledge of 
 the succession of events : its highest function would not 
 be either calculation or mensuration, for these belong to 
 other sciences ; it would be prediction, the determination 
 of future times, by a logical deduction of those partial 
 times already known. 
 
 The whole range of such a science must be strictly con- 
 fined to a knowledge of the duration of events ; of what 
 has come to pass, of what is present, and of what may 
 
 u 3 
 
294 THE PUKE FORMAL SCIENCES. 
 
 happen hereafter : and in the consideration of such occur- 
 rences, their duration, and all relating thereto, is all that 
 we are concerned with ; we have nothing to do with the 
 events themselves, as to what they appear to be, or as to 
 what they are in reality ; just as in geometry, the abstract 
 forms, and not the bodies themselves, are the legitimate 
 objects of the science. So in the contemplation of the 
 universe, in respect only to the abstract forms of its fleeting 
 events, we perceive that they are in a continuous flux or 
 progression : whilst we are yet considering a passing event, 
 the instant of time in which it occurred is present no 
 longer, but has become part of the past ; which will dis- 
 appear in the abyss of oblivion, unless preserved in the 
 records of history. Some events are momentary, others 
 have various degrees of duration ; whilst others, whatever 
 be the lengths of their duration, return again and again in 
 regular series of periodicity. All these take- place, side 
 by side, in an antecedent, contemporaneous, or subsequent 
 order, but all are part and parcel of universal time ; which 
 flows on, as the duration of the universe, in one continuous 
 current, whether partial events cease, or whether man, 
 who is one of these events, is conscious or not of the pro- 
 gression. The idea of time is only a rational idea or con- 
 ception of this duration of the universe ; which duration 
 is the formal condition of continuous existence, and which 
 will abide as the rational form of succession as long as 
 the universe endures. 
 
2<J5 
 
 CHAP. XL 
 
 THE KNOWLEDGE OF CAUSATION, THE SCIENCE OF 
 PHENOMENAL VICISSITUDES. 
 
 Introduction: On the Character of Abstract Science. Arithmetic, 
 Geometry, and Chronometry only concerned with the exterior Forms 
 of Things : but variable Phenomena depend on the inner Constitu- 
 tion of Things. Causes must be searched for below the Surface of 
 Things. Rational Mechanics only treats of Motion The Science 
 of Energetics has been proposed as more comprehensive. A Science 
 required, capable of treating of all Changes, physical, chemical, and 
 vital. Rational Mechanics, a Branch of such a Science. The pro- 
 posed Science of Substance or Hypostatics. Substance, a pure ab- 
 stract Idea of Matter, its Attributes those of Quantity and Quality; 
 a Composition of Causes, the abstract Idea of Forces. Its Defini- 
 tions, Postulates, and Anxioms. The particular Sciences related to 
 the universal Science of Hypostatics. Cinematics, the Science of 
 Motion. Statics and Dynamics. The Idea of Vis-inertia. All 
 Motions Compositions of moving Causes. Remarks on the Laws 
 of Motion. Combination, a Kind of Change, gives the special 
 Science of Rational Chemistry or Chemics. Organisation, another 
 Kind of Change, gives Rational Physiology or Organics. Con- 
 clusion. 
 
 ACCORDING to the statements of the last chapter, a pure 
 science is the knowledge of some formal system ; the body 
 or content of such a system is an abstract idea of the 
 highest generalisation ; and the actuating, or efficient 
 principle of this system is the conscious faculty. The mind 
 obtains the materials by the interpretation of the reason 
 in nature ; with which it constructs the system, and then 
 
 U 4 *\ 
 
296 THE KNOWLEDGE OF CAUSATION, 
 
 by its logical methods, which it possesses in virtue of its 
 being a conscious part of this self-same reason, it causes 
 the system to function in the elaboration of divers 
 intellectual phenomena. 
 
 The laws of thought, the axioms of logical operations, 
 are the types of all natural laws ; which indeed necessarily 
 follows if our former conclusion be accepted, that mind is 
 only the highest development of organic existence : for 
 thus being a part of nature, which is made up of dualistic 
 powers, it is subject to the same laws ; and being self- 
 conscious, it is capable of becoming acquainted with the 
 reason in nature, as systematic knowledge. Nature itself, 
 with all its varieties of conditioned material beings, is 
 essentially a hierarchy of natural powers ; in which all 
 these powers are related to each other according to their 
 degrees of rank. Since, however, every power is twofold, 
 (or one pair of co-existent and co-efficient attributes, 
 potency and reason,) nature assumes a different aspect 
 according to the point of view from which it is regarded. 
 We have already treated of nature as a system of forces, 
 that is, on the potential side ; and also as a system of 
 rational or logical forms ; but the latter consideration, on 
 the ideal side, has not yet been completed. 
 
 We have already seen that in the contemplation of 
 nature, when all its real content, that is, its forces, are 
 abstracted, the ideal form of system alone remains, the 
 knowledge of which is called science, or systematic know- 
 ledge: and since pure knowledge is the consciousness of 
 rational and logical ideas, it follows that a system of these 
 can be no other than logic. This system then is the pure 
 formal archetype of reason, which is an integrant part, or 
 
THE SCIENCE OF PHENOMENA. 297 
 
 moiety of the system of nature ; and co-existent with the 
 other and corresponding half, the system of forces, to 
 which it is a law for the regulation of their efficiency. 
 We have advanced yet a step farther in natural know- 
 ledge : we have not only ascertained that every science 
 must be necessarily based on the purest and most abstract 
 principle of logic, which is par excellence the universal 
 science ; but also that all sciences in relation thereto are 
 particular or special, being only the logic of their respec- 
 tive fundamental ideas. And we have also seen that when 
 these ideas do not relate to specific realities, but to specific 
 formal abstractions, we have the pure sciences of number, 
 space, and time, which are universally applicable to the 
 concrete natural sciences ; and thus become instrumental 
 in the more accurate determination of natural pheno- 
 mena. 
 
 So far then we are in a position to understand the 
 system, the multitude, the magnitude, and the duration of 
 natural objects ; but if we stop short here, our know- 
 ledge of nature will be very incomplete. Hitherto the 
 pure sciences which have engaged our attention have 
 treated only of the general external appearances or phe- 
 nomena, and their relations toward each other, as to order, 
 number, space, and time, most important considerations 
 certainly, but they do not comprise the whole field of 
 exact knowledge. They are concerned only with the 
 exterior forms of things ; but we also desire to know the 
 interior forms of things, what they are internally : we 
 crave after a knowledge of the causes of those protean 
 changes, which all things around us are continually under- 
 going. Now no one can deliberately reflect on these things, 
 
298 THE KNOWLEDGE OF CAUSATION, 
 
 and seriously deny that we stand in need of more know- 
 ledge concerning the -forms of things than we at present 
 possess. It is the fashion of many not only to ignore, but 
 to deride with the bitterest sarcasm, all attempts to search 
 out these obscure subjects : but for the sake of truth, we 
 do not hesitate to state our firm conviction, that the 
 abstract ideas of substance, cause, and effect, are as pure 
 and as universal in their character, as those of number, 
 space, and time. 
 
 The abstract ideas of substance, cause, and effect, are all 
 intimately related together ; indeed they seem to be inte- 
 grant parts of one and the same science : just as in physics 
 we have the subject-matter of the science, which may be 
 either the maximum or minimum of material bodies, as the 
 stars or molecules, and the forces of which these are com- 
 posed, and the phenomena or effects which result from 
 their action and reaction. 
 
 But have we not got such a science ? We think not : 
 but it has been acknowledged as a desideratum, as witness 
 the very recent attempt of Macquorn Rankine to establish 
 a science of Energetics, " which if constituted would be the 
 highest abstraction or generalisation attainable in physical 
 research." So says the " Cyclopedia of Physical Science ;" 
 and as far as we can gather from the brief notice therein, 
 energetics is only intended to include all kinds of motion, 
 the various modified operations of physical forces ; but has 
 no concern with the changes of combination or of organisa- 
 tion. A science of changes, however, cannot be universal, 
 unless it comprises not only the changes of place or of 
 motion, but also those changes which result from the 
 operation of chemical and vital powers. 
 
THE SCIENCE OF PHENOMENA. 299 
 
 If we have rightly apprehended the subject, the science 
 required must be universally applicable to all kinds of 
 changes; and since motion is only one kind of change, 
 the noun-substantive of rational mechanics or mechanical 
 science, it is evident that this science is not what we are 
 in search of. Some have thought that mechanical science 
 is based on the idea of time, which being a universal idea 
 is so far plausible: but we have already attempted to 
 show that the idea of time cannot be employed for such a 
 purpose. There is indeed a very close agreement between 
 the ideas of time and of change. Time is related to a 
 succession of events : and change implies some notion of 
 sequence, for there is an antecedence and consequence in 
 the phenomena of every change. But granting this, it is 
 not conclusive that succession is the principle of change as 
 well as of time; it only shows that time is the higher 
 generalisation of the two, and may be instrumental in the 
 illustration of changes, just as number is logically prior to 
 time, but is not identical thereto, merely because succes- 
 sive periods may be numbered. 
 
 Periodicity, which is related to time, as magnitude is to 
 space, is a regular series of successive events ; and in one 
 sense this may be called a change : but in the strict mean- 
 ing of the word change, or that in which we propose to 
 use it, it does not signify an alternation, but an alteration 
 of things. When anything experiences a change it is not 
 in the same state ; and it is the altered condition which 
 gives rise to the inquiries, What is the nature of the dif- 
 ference which has taken place ? and, Whence comes the 
 change ? whereas, in the case of time, we only observe 
 the duration and periodicity of events, not the nature of 
 
300 THE KNOWLEDGE OF CAUSATION, 
 
 the events themselves, but only their succession ; nor are 
 we concerned with the causes of their origin. 
 
 We may consider natural things abstractedly as formal 
 bodies or substances : there are several kinds of substances, 
 which are denoted by their specific differences, as physical, 
 chemical, and organic substances ; but all may be classed 
 together under the universal or generic idea of substance : 
 and when we seek to know what this pure abstract sub- 
 stance is in itself, we learn that it is the formal counter- 
 part of forces, which together make natural dualisms ; and 
 we ascribe to this abstract substance the formal attributes 
 of quantity and quality. 
 
 When actual bodies undergo real changes, either within 
 their own bodies, or by the concurrence of two or more 
 bodies mutually acting on each other, knowing the com- 
 ponent forces of such bodies, we are able to explain the 
 new phenomena or changes of state, on considering the 
 character of the forces concerned. So in the case of ab- 
 stract substance, knowing that its attributes are quantity 
 and quality, we refer all the changes which it may under- 
 go to an alteration in the relations of these attributes 
 toward each other : so that to preserve the parallel which 
 we are drawing between abstract and concrete bodies, we 
 consider the attributes as causes or formal forces, which 
 acting and reacting on each other produce effects: and 
 whatever variety of aspects these may assume, they are 
 still the same substance, consisting of the same attributes, 
 in different proportions. 
 
 Now in the consideration of a concrete or natural science 
 it was found necessary to treat it both descriptively and 
 rationally ; that is, its objects or subject-matter, both in a 
 
THE SCIENCE OF PHENOMENA. 301 
 
 state of rest and in a state of change, are subjects of 
 inquiry ; the former giving us a knowledge of its objects 
 as they appear to be ; the latter affording an insight into 
 their constitution, thereby enabling us to discern the 
 causes of the changes. Guided by this analogy, and sub- 
 stituting formal ideas for potential realities, we will regard 
 substance in all its varieties as the subject-matter of a 
 universal science; and consider it under both its pheno- 
 menal and causal aspects. Such an inquiry gains some 
 assistance from the character of rational mechanics, which 
 is a particular, or subordinate part, of the universal science 
 in question: for the special science teaches us, that although 
 motions, or changes in place, constitute its immediate 
 objects, the conceptions of substance and forces cannot be 
 altogether ignored ; there must always be something, that 
 is supposed to be moving or tending to motion, if it be 
 only a point in space, or an atom of substance which is 
 the minimum quantity or unit of this conception. Even 
 in the enunciation of the laws of motion, the words body 
 and bodies are introduced ; and we speak as often of the 
 composition of forces as of the co-existence of motions ; 
 this, however, is not correct, for being the laws of an ab- 
 stract science, there ought to be no reference to realities ; 
 it, however, shows what we are insisting on ; that some- 
 thing, though even pure formal substance, must be con- 
 ceived, in order to make our ideas, on such a subject, 
 intelligible. 
 
 When therefore we speak of substance, the pure form 
 of material bodies is intended, and not the actual bodies 
 themselves, which are not only forms but also the real 
 contents of bodies, that is, natural forces; the two con- 
 
302 THE KNOWLEDGE OF CAUSATION, 
 
 jointly constituting natural bodies. In treating then of 
 the abstract science of substance, these forces ought not to 
 be even provisionally employed ; their pure forms only are 
 admissible, and these are causes : so that we go farther than 
 Comte, when he says " that in mechanics we have nothing 
 to do with the origin or different nature of forces ; they 
 are all one, while their mechanical operation is uniform." 
 But we do not agree with him in his condemnation of 
 natural forces, or verce causes, as old metaphysical notions, 
 rendered obsolete by positivism : for we acknowledge 
 causes as the ideal side of powers, of which forces are the 
 real side ; powers, the indissoluble union of these, are 
 beings which are manifested to our senses, as natural 
 objects. 
 
 A universal science is therefore, we think, awanting, 
 which shall hold a similar relation to its particular or sub- 
 ordinate sciences, that logic does to arithmetic, geometry 
 and chronometry ; as a science of a lower degree of 
 abstraction, having a closer relation to natural powers, and 
 bearing a greater resemblance to realities, the form and 
 content more clearly corresponding, all the preceding 
 sciences become subservient to it, or are instrumental in its 
 calculations and mensurations. At first sight this state- 
 ment may seem to be contradictory to our former assertion, 
 that logic is the basis or at the root of all other sciences ; 
 but it is not so : logic is the science of system, the whole 
 of which is obtained by the interpretation of the rational 
 forms of things, the reason in nature. But this interpre- 
 tation depends on the self-consciousness of the rational 
 mind, which knows not only the import of the rational 
 forms or ideas that it perceives, but also knows intuitively 
 
THE SCIENCE OF PHENOMENA. 303 
 
 the logical methods by which these ideas function, and by 
 means of this knowledge it is enabled to deal logically with 
 its conceptions. The mind then as a rational power, self- 
 conscious of its own rational forms, which are concerned 
 in the production of knowledge according to its innate 
 laws of thought, can discern its own mode .of operating ; 
 and since its power is the highest order of all powers, it 
 must possess the attributes of all, and be capable of appre- 
 ciating the forms of all; but its logical forms only relate to 
 knowledge, which is purely that of the degrees of order or 
 system, but has nothing to do with the cause or reason of 
 that order, or of the nature of that efficiency, by which 
 these orders function inductively and deductively. In 
 short, in contemplating the various forms of natural forces, 
 we can logically arrange them into a system, and we can 
 logically again analyse this system into all its parts ; and 
 so far logic is at the foundation of all our knowledge of 
 natural powers, whether on the side of their physical forces 
 as realities, or on that of their rational forms or causes as 
 abstract ideas. But in relation to the constitution and 
 internal changes of things, there is a conception of another 
 kind involved, which is not to be found in the abstract 
 sciences already considered; it is something over and above 
 all the ideas relating thereto, viz. that of causation, which 
 is necessary for the comprehension of all those sciences 
 which relate to some kind of change. 
 
 If we have been so fortunate as to have made our mean- 
 ing understood (which may not be the case, for it is not 
 easy to express oneself clearly and definitely on a subject 
 which the mind is as yet only striving to grapple with and 
 master), it will have been seen that although we have not 
 
304 THE KNOWLEDGE OF CAUSATION, 
 
 at present such a universal science as is under considera- 
 tion, yet that it is possible that such a science may be 
 formed, which shall comprise the particular formal or 
 rational sciences relating to motion, combination, and 
 organisation, which are all the modes of natural changes. 
 
 Such a science, we conceive, to be in strict keeping with 
 our most perfect sciences, must be that of substance : and 
 we would suggest for it the name of Hypostatics. As the 
 figurative magnitudes or figures of space are the imme- 
 diate objects of geometry, so the changes of substance are the 
 objects that will chiefly engage the scope of hypostatics. 
 The dimensions of figures are determined by mensuration, 
 which is the principal function of geometry ; as the dif- 
 ferences of changes or effects are explained by causation, 
 the function of hypostatics. Every substance, that is, 
 every portion, or partial substances, of universal substance, 
 may be regarded as an effect, for all things are in a con- 
 tinual flux of change; and that which we one instant 
 regard as a phenomenon in a statical state, is the next 
 instant altered in appearance, and becomes a new effect, 
 the cause of which is a subject for investigation. So, in 
 like manner, as the multitude and magnitude of things 
 have been carefully studied, and the sciences of arithmetic 
 and geometry evolved therefrom ; there can be no good 
 reason why a science, such as that of hypostatics, may not 
 be derived from the rational interpretation of the vicissi- 
 tude of things. 
 
 In attempting to arrive at such a science, it is requisite, 
 in the first place, to ascertain the nature of substance 
 itself, which is the subject of change : and why, when 
 the change does take place, the substance is still the same, 
 
THE SCIENCE OF PHENOMENA. 305 
 
 only in a new or different condition ; which altered condi- / 
 tion, and the cause thereof, require to be determined. 
 The substance which we have now to treat of is universal ; 
 it is no special substance which is capable of motion, or of 
 combination, or of organisation; but is pure substance 
 only, having the attributes, equally pure and abstract as 
 itself, of quantity and quality : just as physical attraction 
 and repulsion are the forces, or verce causce, of matter in 
 the world of realities ; which matter also varies in its 
 state or condition according to the relative proportions of 
 its constituent forces : or just as a body in motion is 
 actuated by two forces tending in different directions; 
 the character of which motion depends on the relation of 
 its forces towards each other. 
 
 Substance itself, then, is a composition of quantitative 
 and qualitative causes, which are co-existent, but the 
 antithesis of each other : as a universal, it comprises the 
 whole of these causes, which cannot become more or less, 
 consistently with the law of conservation ; but particular 
 substances may be differentiated by the proportion in 
 which these attributes are distributed throughout the 
 whole system ; just as in the case of logical extension and 
 intension these attributes being in an inverse ratio to each 
 other, as these vary, so must the properties of the parti- 
 cular propositions to which they belong. It will be seen 
 by this, that we are making a parody of the physical or 
 real side of nature, such as we have already described as 
 a system of forces : and so it must be, for the forces and 
 the rational forms of powers perfectly correspond; the 
 one is that which effects the actual changes, and the other 
 
306 THE KNOWLEDGE OF CAUSATION, 
 
 which imparts the form of the change according to its 
 rational design. 
 
 The axiom of hypostatics, that every effect must have 
 its cause, or differently expressed, that every cause is known 
 by its effect, conveys the notion that one cause only is 
 concerned in causation ; but, as already observed in the 
 introductory chapter, this is an abbreviated form of speech 
 in common use ; and which may be justified, since it is 
 the plus or efficient cause which is immediately concerned 
 in the change, and which imparts its own character to the 
 resulting effect. So that, virtually, an effect is the mani- 
 festation of a single cause : but in truth there must needs 
 be also the simultaneous presence of another, a resisting 
 cause ; for without action and reaction there can be no 
 efficiency, in this conditioned world of nature. 
 
 Now inasmuch as the substance is only an ideal form, 
 the change itself, which substance may undergo, must be 
 also an abstract idea ; a change, however, which is a single 
 conception cannot be thought of alone, it must be as a 
 change of some substance, just as we cannot form an idea 
 of motion itself, but it must be presented to the mind as 
 something moving, even though that something be only an 
 abstract idea. In all changes, the effects produced are 
 themselves only the substances concerned therein, in some 
 new condition ; they are, therefore, invariably compositions 
 of causes, co-existent and antagonistic causes, inseparably 
 necessary for the constitution of the special effect. If the 
 causes concerned in a change be equal, the result is an 
 equilibrium, or neutralisation of the opposite attributes ; 
 but if either one or other of the constituent causes be in 
 excess, it imparts its character to the change. In the 
 
THE SCIENCE OF PHENOMENA. 307 
 
 latter or plus state of the change, the effect may become 
 an exciting cause to another change, and so on until the 
 intensity of the excess is diffused through the substances 
 engaged in these operations, and all return to a state of 
 equilibrium. 
 
 On this view of the subject, we arrive at the following 
 general principles concerning hypostatics. First axiom, 
 Every effect must have a cause. Second axiom, Every 
 effect is a composition of causes ; consequently, causes are 
 co-existent in and commensurate with the effect. Third 
 axiom, Every effect is the result of the action and reaction 
 of its causes ; consequently such causes are always opposite 
 or antagonistic. Fourth axiom, Effects, in their character, 
 depend on the relation of their causes ; hence the nature 
 of a cause is manifested by its effect, or resulting pheno- 
 menon. 
 
 By this statement it is evident that the axioms of hypo- 
 statics comprise the whole content of the laws of motion : 
 we have only to substitute the ideas of moving and resist- 
 ing causes for the pure causes, the particular for the 
 universal, and the idea of motion or change of place for 
 the more general idea of pure change ; and we then obtain 
 rational mechanics, just as logic becomes geometry when 
 to the more general ideas of order, that of space is super- 
 added. This has already been pointed out by Whewell,* 
 who, when treating of the idea of cause, has observed that 
 " the three axioms of causation, now stated, are the funda- 
 mental maxims of all reasoning concerning causes, as to 
 their quantities; and it will be shown in the sequel, that 
 
 * Philosophy of the Inductive Sciences, vol. i. p. 177. 
 X 2 
 
308 THE KNOWLEDGE OF CAUSATION, 
 
 these axioms form the basis of the science of mechanics, 
 determining its form, extent, and certainty." 
 
 From what has now been said concerning the proposed 
 science of hypostatics, some general notion may have been 
 formed concerning its objects and its functions ; but before 
 concluding this subject a few more remarks may be made 
 thereon. 
 
 In the construction of hypostatics, the course to be 
 pursued must be the same as ought to be followed in every 
 science. In the first place, it may be defined as the 
 science, or systematic knowledge, of substance, which is 
 its noun-substantive, or fundamental idea. This universal - 
 substance must be then analysed into its various parts, and 
 each of these parts, in order to their, clear recognition, must 
 be determined by their respective definitions, and marked 
 by distinct names, so that nomination and definition are 
 preliminary operations. 
 
 We have already marked the fundamental principle of 
 hypostatics by the name of substance, and we define it to 
 be the formal constitution of natural beings or powers, or 
 in other words, the pure form of nature : and since all 
 natural bodies are dualisms, it follows that, on their ideal 
 side as well as on the real, they must be similarly consti- 
 tuted; and if so, the more precise definition of substance is, 
 that it is a formal dualism of quantity and quality ; and 
 then quantity is the basic attribute, and quality the specific 
 attribute of substance. The maximum of substance will 
 be its entire system, and its subordinate parts will be 
 masses of various extent ; whilst the unit or minimum of 
 substance is an atom, that which cannot be subdivided. 
 In all this, it is evident that we are only regarding those 
 
THE SCIENCE OF PHENOMENA. 309 
 
 abstract terms which we are in the habit of using in con- 
 nection with material bodies ; thus, we commonly speak of 
 an atom or of a molecule of matter, or a material atom, 
 &c. ; and of an atom of material or chemical substances. 
 How far we may be able to gather together, and appro- 
 priate such abstractions for the purposes of hypostatics, 
 remains to be determined : but we are inclined to think 
 that they include all those general expressions, such as 
 those of agent, reagent, and action; active and passive, 
 action and reaction, equilibrium, and the like : all, in short, 
 which as pure formal ideas, relating to natural bodies and 
 natural powers, are capable of universal application. 
 
 The postulate requisite for the .science of substance, 
 seems to be that it is possible for any given part of sub- 
 stance, which is demonstrable, to be made up of atoms or 
 units of substance, though in themselves inappreciable; and 
 that the change of any substance, which is an effect, may 
 be brought about by an alteration in the relative propor- 
 tions of its attributes. 
 
 Concerning the axioms of this science, according to which 
 substances function, we have already made several re- 
 marks, and enumerated four of them, which are probably 
 sufficient for all the purposes of the science. To attempt to 
 develope this subject more fully, would involve us in such 
 minute details as would be inconsistent with the character 
 'of this work; the object of which is to trace out the 
 filiations of known sciences, so as to collect them into a 
 common system : and in so doing to notice the vacancies 
 therein, and to indicate in what manner these blanks may 
 possibly be filled up. Such an undertaking cannot be 
 expected to be completed by a first attempt, even should 
 
 x 3 
 
310 THE KNOWLEDGE OF CAUSATION, 
 
 the suggestions in any measure prove to be correct : but 
 it may ultimately tend, by the labours of others, to accelerate 
 the advancement of knowledge. 
 
 Having now considered the universal science of sub- 
 stance, which is concerned with all descriptions of changes, 
 to which its laws are equally applicable, we now turn to 
 those special kinds of change, which, in addition to the 
 generic character, have specific ideas which make their 
 difference : and on each kind of change we now proceed 
 to make a few brief remarks. 
 
 Rational mechanics, or mechanical science, has been 
 long acknowledged as a branch of pure mathematics : we 
 have endeavoured to show that it is not a universal science, 
 like that of space, because its fundamental idea of motion, 
 or change of place, is not an idea of the highest generalisa- 
 tion, appertaining only to one kind of change : and if 
 this be accepted as conclusive, it follows that the science 
 in question is only a branch of the pure science of sub- 
 stance, hypostatics, which is one of the universal mathe- 
 matical sciences. Rational mechanics is the science of 
 motion, or cinematics, as it ought to be called ; this term 
 is much in use, but by most only in connection with 
 statics and dynamics, the two latter so-called sciences 
 having relation to the forces which produce, or tend to 
 produce motion. As already stated, we consider that cine- 
 matics, as a science, is adequate for the treatment of all' 
 these subjects ; just as astronomy comprehends, not only 
 the description of its objects, whether at rest or in motion, 
 but also an explanation of their different conditions, by 
 the dynamical actions of the antagonistic forces which 
 are concerned in the production of all astronomical pheno- 
 
THE SCIENCE OF PHENOMENA. 311 
 
 nomena. Statics and dynamics, therefore, are only re- 
 garded by us as the relative states or conditions of the 
 moving causes, which function as motion ; the various 
 kinds of motion are, then, the effects of special causes, and 
 are the objects or subject-matter of cinematics. If we 
 persist in treating of statics and dynamics as special 
 sciences, or distinct branches of science, to be consistent 
 we ought, in the natural sciences, to have sciences of the 
 centripetal and centrifugal forces, as we have indeed now 
 those of other forces, heat, electricity and magnetism, all 
 of which are, we think, contrary to the very principle of 
 a science, which is systematic knowledge : indeed we can 
 only know forces by their effects, and they are always 
 complex composition of forces, which as phenomena are 
 capable of being immediately known as mental ideas. 
 
 We are confirmed in our view of the subject in object- 
 ing to the present constitution of rational mechanics, by 
 the great uncertainty which prevails in the treatment of 
 statics and dynamics; a perplexing circumstance which 
 has often attracted attention. " Statics," says Comte*, " was 
 the only possible method in the early days of science : but 
 since Galileo's time, dynamics, the method of seeking the 
 conditions of equilibrium through the laws of the composi- 
 tion of forces, has been more generally followed. At first 
 glance, it does not appear the more rational; dynamics 
 being more complicated than statics, and precedence being 
 naturally to the simpler. It would, in fact, be more 
 philosophical to refer dynamics to statics, as has since 
 been done, but only in the case of uniform motions." 
 " It is usual, however, to consider statics as a particular 
 
 * Positive Philosophy, book i. chap. iv. sect. 1. 
 x 4 
 
312 THE KNOWLEDGE OF CAUSATION, 
 
 case of elementary dynamics ; but simple as may be the 
 operation, and great as may be the practical advantage 
 gained by this method of proceeding, it would be satisfac- 
 tory to return, if we could, to the method of the ancients ; 
 to leave dynamics on one side, and proceed directly to 
 the investigation of the laws of equilibrium, regarded by 
 itself; by means of a direct general principle of equili- 
 brium. A science must be imperfectly laid clown, as long 
 as it is necessary thus to pass backwards and forwards 
 between its two departments." 
 
 At all events, it is evident that the principles of science, 
 thus constituted, cannot be rightly apprehended, and it is 
 reasonable to suppose, in such a case, that the defect is not 
 trivial, not a mere imperfection which may be hereafter 
 removed, but that it is radically insuperable ; for in any 
 science, much more in a pure science, intelligible clearness 
 and definite precision are indispensable requisites. 
 
 Cinematics, the science of motion, treats of the whole 
 system of motions, which comprises all kinds of motion, 
 and their relations toward each other ; and this necessarily 
 implies a knowledge of moving causes, and their variable 
 relations ; for motion is a composition of formal forces or 
 causes. Now every substance capable of being moved, 
 that is, every moveable substance, is actuated by its con- 
 stituent causes ; each of which tends to move the substance 
 in an opposite direction to each other : so that if no motion 
 takes place in either direction, either toward or from the 
 common centre of action, the substance is in a state of 
 rest ; and its moving causes are consequently equal, or in a 
 state of equilibrium. Make the smallest addition to the 
 energy of either cause, when in this condition, and the 
 
THE SCIENCE OP PHENOMENA. 313 
 
 substance will instantly move in the normal direction of 
 the efficiency. Whichever direction the moving substance 
 may take, it is self-evident that if it be required to reverse 
 its motion in the opposite direction, we cannot now accom- 
 plish it by the same amount of energy as that which first 
 put it in motion ; we must first employ a sufficient power 
 to balance its antagonist, that is, the equilibrium must be 
 restored, and then superadd an excess which will subvert 
 the statical state of the substance, and by its dynamic 
 influence cause it to move in the new direction with a 
 velocity equivalent to the excess employed. 
 
 All substances are moveable ; indeed universal substance, 
 or the entire system, is not only moveable, but perpetually 
 in motion ; but since the moving causes of the system, 
 taken in their totality, are invariably conserved in a state 
 of equality, the resulting motion is so equable, that, like a 
 top when it sleeps, it would, could we see it, have the ap- 
 pearance of being in a perfect state of rest. And even the 
 parts of this universal substance, when constrained by a 
 great excess of the cause tending to the centre, so that in 
 respect to its local position it is rigidly at rest, yet even 
 then, though the antagonist moving causes of the sub- 
 stance are not co-equal, yet they are still co-existent, and 
 their efficiency is not destroyed ; they are ever efficient, 
 they neither slumber nor sleep, but are ever ready to start 
 into perceptible activity should extraneous energy inter- 
 pose to turn the balance in favour of such a phenomenon. 
 A cause then which is equalised by another, whether a 
 moving or any other cause, is not annihilated, but only 
 rendered latent by a kind of neutralisation ; and such a 
 condition gives us an important point of departure in all 
 
314 THE KNOWLEDGE OF CAUSATION, 
 
 our investigations concerning motions and their causes : 
 we know not indeed the absolute amount of energy which 
 is exerted on either side in any given equilibrium ; but, be 
 it large or be it small, it matters not, for all our know- 
 ledge can be but relative : but we can determine in any 
 case the amount of energy requisite for bringing any sub- 
 stance into such a statical state ; and then starting from 
 this point, we can estimate the value of the actual moving 
 force by the motions produced. 
 
 This principle is only one of the many forms resulting 
 from the dualistic constitution which pervades all nature, 
 and which we have symbolised in our archetypal correla- 
 tion : it is the same as that for which we are indebted to 
 D'Alembert, by which the equations of the motion of 
 any system may be established ; and which, combined with 
 that of virtual velocities, enables us to solve very intricate 
 problems of motion. In fact, these mechanical principles 
 may be all referred to the second, or Newton's, law of 
 motion, that of the equality of action and reaction ; which 
 in turn may be traced up to the higher generalisation of 
 the antagonism of causes, as enunciated in the third axiom 
 of hypostatics. 
 
 There is one notion which has been adopted in rational 
 mechanics, the idea of a vis inertia, and which is tenaciously 
 retained : it is true that it is no longer considered to have 
 any real foundation, but is valued merely as a convenient 
 expression. The fact is, that it is a monument of our 
 ignorance; but one enveloped in such an appearance of 
 mystic knowledge, that it imposes on the student, and so 
 perverts his understanding as to favour its retention. 
 Some effort should be made to eradicate this notion : there 
 
TttE SCIENCE OF PHENOMENA. 315 
 
 is enough to learn worth knowing ; and we need not per- 
 plex our youths with learning the conventional meaning 
 of an hypothesis acknowledged to be untenable. 
 
 According to the idea of vis inertia, " all nature is sup- 
 posed to be inert, motionless, and lifeless, and that action 
 or activity can be impressed on it solely by external 
 energies or forces : but this is not true, for every part of 
 nature is the centre and source of manifold and multiform 
 activities." "But the hypothesis of inertia is not only 
 convenient, but necessary for the development of science ; 
 for an inert point is theoretically required whereon forces 
 may act to produce motions." We are, however, inclined 
 to think that in the case of forces and bodies, moved that 
 is on the real side of nature, no such consideration is 
 necessary : every body that is to be moved must first have 
 its resisting, or statical, force equalised ; and this resisting 
 force is not an unknown vis inertia; and so when it begins 
 to move it starts not from an inert state, but from that of 
 equilibrium, in which state it is ready to respond to the 
 external energy or force. And so, mutatis mutandis, the 
 same explanation serves for the abstract forms of bodies 
 and forces, viz. for substances and causes : for the real 
 and ideal perfectly correspond, depending on the self-same 
 reason. 
 
 This idea of inertia is employed even in a higher sense, 
 agreeable with which the first law of motion is frequently 
 called the law of inertia. Bodies being in themselves 
 regarded as inert, they only move as they are acted on : so 
 that a body, or an abstract body or substance, when moved 
 by any force, would, if not disturbed, move on for ever 
 in a straight line and with an uniform velocity. 
 
316 THE KNOWLEDGE OP CAUSATION, 
 
 Any substance in a state of equilibrium would afford a 
 much more rational point of departure, and would give the 
 same result under the like condition of meeting with no 
 resistance or interference of any kind. We may imagine, 
 but by mental abstraction alone is it possible to consider, 
 what would be the modus operandi of any one kind of 
 force ; and as we know that each force has its own peculiar 
 direction, of course, if it could be insulated, this line of 
 action would be the only one in which it could act. So 
 far it is perfectly legitimate to form such a conception ; 
 for it is necessary, in order to understand the kind of 
 motions which actually take place, to know the character 
 . of the individual forces concerned .therein. No motion 
 can result from the operation of a single force, there must 
 in every case be action and reaction ; for motion is a 
 composition of forces : and such motion, therefore, can 
 never be more than an approximation to a straight line ; 
 for however one force may predominate, and impart its 
 peculiar direction, it can never be absolutely separated 
 from its co- existent, that is, its correlative force. Such a 
 possibility would stultify the second and third laws of 
 motion. Moreover, whether we deal with real or abstract 
 motions, the condition of the first law of motion, which 
 states, "if not disturbed," requires that which may be 
 imagined, but which never did nor can occur in relation to 
 anything in nature, whether real or ideal. No force of any 
 kind can act but in relation to all around ; and hence it is 
 that the result of any action whatever is not pure and 
 simple, but complex ; and it is this very complicity which 
 makes analysis possible, on which all science depends. 
 
 By this statement we are not denying that we may, by 
 
THE SCIENCE OF PHENOMENA. 317 
 
 mental analysis, abstract the single elementary forces ; and 
 this way objectify them, and note their peculiar attri- 
 butes : but what we are desirous of maintaining is, that as 
 such forces are never so insulated, but always occur in 
 pairs or dualisms, it is not legitimate to frame a law con- 
 cerning that which is non-existent, both as regards the 
 force itself and the condition of its action. A law, 
 whether physical or logical, is supposed to be an expres- 
 sion of that rational rule by which natural phenomena 
 are regulated ; it does not relate to things that may be, 
 but to those which actually occur in nature : and for this 
 reason we assert that a law, purporting to be a natural 
 law, must be consistent with the constitution of nature. 
 
 We need not here repeat what has been said concerning 
 the axioms of hypostatics ; but must rest content with 
 stating, that it is only necessary to add to their general 
 terms the differential ones which specially belong to 
 motion, and then they become the laws of motion. The 
 latter are usually stated in the chronological order of their 
 development: thus, the 1st is Kepler's, the 2nd Newton's, 
 and the 3rd Galileo's. We have, however, reversed this 
 order, following that of their logical relation : and we are 
 inclined to think that if the established laws of motion 
 had been so arranged, it would have appeared more start- 
 ling, after Galileo's law of the co-existence of motions, to 
 enunciate the law of Kepler. 
 
 Cinematics may be divided into subordinate branches, 
 according to the kind of motions concerned, which are 
 very various, as continuous motions, projections, undula- 
 tions, and polar motions. 
 
 Hypostatics may, in a sense, be called a temporo- 
 
318 THE KNOWLEDGE OF CAUSATION, 
 
 spatial science ; but its relations thereto are of a very 
 general and evanescent character : whereas cinematics is 
 very closely related to space and time, and derives great 
 assistance therefrom in the description of its phenomena. 
 And thus it is in each succeeding science ; its special idea 
 seems to become more and more complex, connoting a 
 wider sphere of qualities, including as it were all preceding 
 ideas ; just as natural beings arise one above another in 
 the complicity of their attributes, until they terminate in 
 man, who is a microcosm of all creatures. 
 
 Advancing another step in our progression, we pass 
 from the idea of motion to that of combination, which re- 
 lates to those changes which chemical substances undergo ; 
 as motion relates to those of physical or material sub- 
 stances. 
 
 As motion is not one thing, but a compound of moving 
 forces of a different character, so combination is a com- 
 pound of distinct combining forces, or rather causes. 
 Whenever a chemical change takes place, it is effected by 
 the operation of chemical causes ; and the result thereof 
 is a combination, which is another form of chemical sub- 
 stance. The science of combination, therefore, must be a 
 pure science, all the objects of which are perfect abstrac- 
 tions of chemical powers and their relations : such a 
 science must not be confounded with chemistry ; and for 
 distinction sake it may be called rational chemistry, or 
 enemies, bearing the same relation to chemistry as cine- 
 matics does to physics. 
 
 The possibility of establishing such a science as rational 
 chemistry engaged Comte's attention ; and he clearly 
 indicated that the success of such an attempt must depend 
 
THE SCIENCE OF PHENOMENA. 319 
 
 on correctly apprehending the nature of chemical combina- 
 tion. Some of his remarks on this subject, at first sight, 
 seem very startling ; but when closely examined are found 
 to be very sagacious. "If," says he*, "we could not hold 
 at once the grand principle of the dualism which pervades 
 chemistry, and constitutes its homogeneous character, and 
 also the doctrine of definite proportions, I should not 
 hesitate to sacrifice the latter; for it is more important 
 for chemical progress to grasp the great principle of 
 systematic dualism, than to advance our investigations by 
 the use of the numerical rule. Even after this clearing of 
 the field, we could not accomplish the desired generalisa- 
 tion, if we had not taken a new stand in regard to the 
 ternary and quaternary substances. The rigorous dualism 
 which I have before, and in a higher view, shown to be 
 necessary, seems to supply, naturally and finally, the needs 
 of the doctrine of definite proportions." Again: " In an 
 indirect way electricity may operate favourably for chemi- 
 cal science, by its binary antagonism suggesting the 
 extension of dualism among compounds, which as yet are 
 supposed to be more than binary. Berzelius appears to 
 have felt this connection, and he would probably have 
 erected dualism into a fundamental principle, but for his 
 subjection to the old division into organic and inorganic. 
 For a chemical philosophy, we do not want new materials 
 so much as the rational disposition of the details which 
 already abound, by reducing all combinations, according to 
 the principle of dualism, into one body of homogeneous 
 doctrine." 
 
 * Positive Philosophy, vol. i. p. 331. 
 
320 THE KNOWLEDGE OF CAUSATION, 
 
 The idea of combination is very different from that of 
 cumulation, or even aggregation ; it is the union of two 
 distinct chemical causes, the rational forms of chemical 
 powers ; and the resulting change, the new chemical sub- 
 stance, is characterised by its own peculiar attributes, which 
 are more or less unlike those of its constituents. In the 
 case of an effect, or of a motion, the causes concerned in 
 the respective change cannot be 'demonstrated by the 
 dissolution of their union ; but it is not so in the case of 
 combination; for each combining or chemical cause, on 
 account of its complex constitution, is capable of an indi- 
 vidual existence, so that the nature of each combination 
 can be ascertained by analysis, and the accuracy of the 
 result tested, synthetically, by reunion of the individual 
 constituents. We have said that every chemical combi- 
 nation is a dualism of combining causes ; but it does not 
 follow that either, or both. of these, are simple; they may, 
 on the contrary, be exceedingly complex ; thus either con- 
 stituent may be reduced successively into many different 
 compounds of a simpler character. But however complex 
 compounds may be, they are, or ought to be, theoretically 
 reducible into two constituents, which, as chemical causes, 
 are co-existent and opposite; one cause being the basic 
 or quantitative, and the other the typed or qualifying 
 cause. And it is the knowledge of this fact which often 
 leads, in analytical experiments, to the selection of the 
 kind of reagent we employ, according as it is desired to 
 separate one or the other of the ingredients ; thus the 
 basic or the typal cause, when in combination, may be 
 removed by substituting another of the same kind which 
 has greater combining energy than the one to be displaced : 
 
THE SCIENCE OF PHENOMENA. 321 
 
 and by a repetition of this process, first on the basic, and 
 then on the typal side, or vice versa, we obtain a knowledge 
 of the composition of the original compound. Not an 
 inferential knowledge, as in the case of physical analyses, 
 but an actual demonstration, by obtaining the individual 
 constituents in a state of distinct separation. 
 
 Should it be deemed expedient to gather together all 
 the abstract principles of chemistry, and to constitute with 
 them a science of combination, or chemics, the task would 
 not be very difficult when the general science relating to 
 pure changes has been well established ; for then all that 
 would be requisite would be to conjoin the special idea of 
 combination to that of substance in the universal hypo- 
 statics, and we should have a perfect exemplar for its 
 construction. But, in the meantime, all that we can now 
 do is to point out the position of such a science in the 
 system, and to indicate its filiations with the other sciences, 
 which we have endeavoured to do in the few preceding 
 remarks, but perhaps too imperfectly for any practical 
 application : we must however hasten on to complete 
 the outline of our sketch. 
 
 The only particular kind of change remaining to be 
 noticed for the completion of our knowledge concerning 
 the formal side of nature, is that of organic changes which 
 result in organisation. This kind of change is the most 
 complicated of all, comprising not only motions and com- 
 binations, but something more peculiar which characterises 
 its specialty. 
 
 Each single chemical or combining cause is capable of 
 an individual existence, that is, apart from all other 
 chemical causes ; because it can form a dualism or compo- 
 
 Y 
 
322 THE KNOWLEDGE OF CAUSATION, 
 
 sition of causes, by union with physical causes, and in such 
 a compound, which is the formal representative of chemical 
 elements, the physical cause or causes become the basic, 
 and the combining cause, the typal or specific constituent ; 
 and it is this capacity to form such definite and indis- 
 soluble dualisms that enables them to maintain their in- 
 dividuality ; for no single cause or power can exist alone 
 as a natural being. Though each chemical cause can be 
 thus insulated, it is only as a chemical substance, using this 
 term in an abstract sense, yet it is not a combination or 
 chemical compound; it is necessary before such can be ob- 
 tained that two chemical causes at least should be conjoined, 
 in which union one acts the part of a basic and the other 
 of a typal cause ; corresponding with the abstract notion of 
 reagent and agent, without which there can be no combin- 
 ing action and reaction resulting in combination. 
 
 Such in a few words is the character of those specific 
 changes called combinations, and from which it may be 
 readily inferred that whilst we can by abstraction restrict 
 our attention to the chemical changes only, yet in actual 
 reality, that is, in chemical bodies, various kinds of motions 
 must at the same time occur, because the basic constituent 
 of each combining substance is a dualism of physical 
 causes which are manifested as the attributes of physical 
 or material substance. Now the character of organisation, 
 though not the same as that of combination, has a consi- 
 derable analogy thereto; it is twofold, that is, a dualism 
 like all natural things, whether real or ideal: each individual 
 organism consists of a basic and a typal cause ; the latter 
 is a specific organic or vital cause, but the former is a very 
 complex chemical substance or combination, and as such 
 
THE SCIENCE OF PHENOMENA. 323 
 
 not only chemical but also physical. So we see that it is 
 to its complex nature that each chemical cause owes its 
 capability of an individual existence, which is perfectly 
 stable and durable, for it cannot be reduced to a lower 
 denomination ; and it is owing to the greater complicity of 
 constitution in organisation, that the latter enjoys a higher 
 order of individuality, becoming a system within itself; so 
 that without the concurrence of any other individual it 
 can undergo and accomplish most intricate and numerous 
 series of changes, which are manifested as the phenomena 
 of organisation. 
 
 The idea of organisation, in the abstract, is the universal 
 system of all organic changes ; all of which have in com- 
 mon certain generic characters : they are all compositions 
 of chemical or basic causes, and of typal organic causes ; 
 and it is by the ever varying action and reaction of these 
 causes on each other that the ever changing phenomena 
 of organisation are produced. But multifarious as these 
 are, they may all be reduced to three grand processes 
 which are mutually related ; the phenomena of acquisition) 
 appropriation, and utilisation. The particular parts of 
 this universal organisation are very multitudinous, each of 
 which is differenced from the others by specific attributes, 
 which mark the various species of organisms : these attri- 
 butes are not respectively mere differences, but such as 
 those of different degrees of order, all related together, but 
 progressively rising one above another, so as to include 
 that which has gone before, with an additional something 
 which is peculiar ; so that, by ascending gradations of 
 generalisation, the whole can be collected together into 
 the universal that constitutes the system. Each part of 
 
 Y 2 
 
324 THE KNOWLEDGE OF CAUSATION, 
 
 the organisation, that is, each organism as regarded in its 
 individuality, is itself a universal or system of a subor- 
 dinate degree : and according to its position in the 
 hierarchy of organic beings so is its dignity ; that is, the 
 number of its properties by which it is connoted. The 
 specific or distinguishing cause of each organism is un- 
 ceasingly exercised, as is indicated by the incessant changes 
 which it undergoes, which imply a constant activity of 
 functions: in many individuals, however, there is ap- 
 parently very considerable suspensions of animation, both 
 periodical and accidental ; in many cases we know that 
 the living functions are only partially, but not totally in- 
 terrupted ; and it is not improbable that whilst there is 
 life there are always some changes going on, though in- 
 appreciably small. 
 
 A grand characteristic of all organisation is, that whilst 
 as a whole its existence is conserved, yet its individual parts 
 are always suffering dissolution : their specific principle 
 becomes detached from the basic or chemical, in conse- 
 quence of some injury or deterioration ; and thus the con- 
 currence of the dualistic causes, that composition of forces 
 so requisite in every organism, is necessarily subverted. 
 The general dissolution, which would follow the unim- 
 peded operation of such a process, has been provided 
 against by the function of reproduction : each specific or- 
 ganism has its own peculiar method of effecting this, as 
 well as in all other kinds of functions ; and all such differ- 
 ences serve to enable us to discriminate between various 
 organisms. But various and complicated as this function 
 is in all its details, yet, viewed abstractedly, its rationale 
 is very simple ; and in accordance with the general 
 
THE SCIENCE OP PHENOMENA. 325 
 
 routine which characterises all functions. Each kind of 
 organism acquires materials from the medium in which it 
 lives, by means of its physical or basic causes, which are 
 subservient to the directing energy of its specific cause : 
 and having obtained its materials by means of the same 
 causes, conjoined with the chemical causes, it selects, 
 therefrom, retaining some, and rejecting others. And after 
 divers manipulations, by which the materials are adapted 
 to its purpose, it directs the employment thereof in con- 
 structing organs, according to its peculiar rational designs : 
 such organs, whether the mere enlargement, or reproduc- 
 tion, of former organs, or the development of inferior into 
 higher organs, or even of new and additional organs, are 
 still, in every case, but the self-same organism; and as 
 such continue to be actuated by the same typal or specific 
 cause. And, in like manner the dualism functions, pro- 
 ducing certain actions or organic changes, which are means 
 to certain predetermined ends ; the whole process termi- 
 nating in adaptations useful for the welfare of the creature. 
 Now the germ-cell, produced in the function of reproduc- 
 tion, is no other than such an additional organ, which, whilst 
 a portion of the parent, is on the same footing as all other 
 parts of the individual organic system ; and, consequently, 
 as such, it is a living organ, though dependent : there re- 
 mains but the discharge of another function by the same 
 individual vital cause (or by the conjoint operation of an- 
 other individual organism of the same kind, but the latter 
 need not be insisted on, being only one of the many in- 
 stances in which the operations of nature are so richly 
 diversified, for the case of hermaphrodites shows that it is 
 not an absolutely necessary condition), by which it ac- 
 
 Tf 3 
 
326 THE KNOWLEDGE OF CAUSATION, 
 
 quires a higher condition, that of being able to enjoy an 
 independent state of existence, and to exercise all the 
 functions which its parent previously discharged. 
 
 Every organism has commenced its existence as a sub- 
 stance actuated by an animating principle: it cannot 
 originate its own being ; its basic part must have been 
 prepared, that is, acquired from chemical substances, and 
 appropriated by some pre-existing cause, as a habitation 
 or indispensable medium for containing and enabling its 
 animating principle to function. The conjunction of these 
 two distinct causes is requisite for every part, as well as 
 the whole system of organisation. So that, even in the 
 discharge of one of the highest and most complex of 
 organic functions, the energising principle follows the 
 universal formula of acquisition, appropriation, and utili- 
 sation : a formula which may well be called universal, for 
 it is, in truth, but the expression in other words of the 
 logical methods of definition, generalisation, and demon- 
 stration, which pervades all things as the reason in nature. 
 There is then, on this view, no repetition of acts of crea- 
 tion ; no continual renewal of the vital principle on the 
 birth of each kind of creature: but each specific life is 
 continued by a propagating faculty which cannot be per- 
 fectly comprehended ; but which may be as well under- 
 stood, as any other faculties of natural powers ; that is, as 
 causes they can only be known by their effects; which 
 are to the conscious mind facts with which we must rest 
 content in the present finite condition of our intellects. 
 
 All organic changes, though following one and the same 
 routine, are capable of being arranged under several dis- 
 tinct heads. The first and most general class of such 
 
THE SCIENCE OF PHENOMENA. 327 
 
 changes comprises those of growth and reproduction, which, 
 as we have just said, are fundamentally one, having rela- 
 tion to the general idea of increase : just as in arithmetic, 
 the sum obtained by addition and the product arising from 
 multiplication are, at the root, of the same character, being 
 variations only of one and the same principle. The incre- 
 mental changes of organisation are, like motions and com- 
 binations, compulsory according to the innate laws of the 
 causes concerned therein : that is, the causes and all the 
 conditions of a given change being known, we can, under 
 precisely the same circumstances, predict the result which 
 will follow. The organic cause is indeed a reason-directed 
 cause, but on the platform of mere. vegetative existence it 
 is a passive unconscious cause, similar to that which is 
 concerned in physical and chemical phenomena, which are 
 usually regarded as definitely conditioned or necessitated. 
 In the case of many organic causes this condition is the sole 
 mode of action : but there are some causes which, in addi- 
 tion thereto, enjoy the faculty of consciousness, which 
 raises them into a higher class of existence. Some con- 
 scious organic causes, have, according to their degree, the 
 capacity of perceiving and knowing their sensations, and 
 using this knowledge for the guidance of their actions: 
 and when this faculty has attained its highest development, 
 as not only conscious of the changes relating to the ope- 
 rations of the basic cause with which it is associated, but 
 also rationally conscious of the laws which regulate these 
 changes, it then acquires a corresponding influence over 
 the subordinate causes, making them subservient to its 
 designs ; and thus acquiring also the greatest freedom of 
 action, as a voluntary cause or will. Such an organic 
 
 Y 4 
 
328 THE KNOWLEDGE OF CAUSATION, 
 
 cause of the most exalted degree is still only one cause : 
 it possesses in common with reason all the lower faculties, 
 which are enjoyed by subordinate organisms ; but all these 
 are only various modes of the self-same cause. For since 
 the highest cause comprises within itself all the attributes 
 of the lower causes, it is capable of exercising either of 
 them according to its exigencies. The mind is one kind of 
 organic function, as much as locomotion is another : there 
 can be no line of demarcation drawn between body and 
 mind ; throughout all nature there is a gradual ascending 
 scale of being; but all are intimately related together, and 
 united into one common system. 
 
 The few abstract principles of biology which have been 
 referred to, may suffice to show in what manner we ought 
 to proceed in attempting to work out a pure abstract 
 science of organics, or the systematic knowledge of 
 organic substances. This includes not only the descrip- 
 tion and classification of all the abstract ideas relating 
 thereto ; but also the explanation of all organic changes, 
 which are only abstract organic substance under new or 
 different aspects. Such a science within its sphere may 
 be as pure and exact as cinematics: its object will be to 
 determine the nature of the various organisms, and their 
 functions by organic causation ; as that of cinematics is to 
 determine the various motions by a knowledge of the action 
 of moving causes. And as organics is a very complex 
 science, so it occupies a corresponding rank in the hier- 
 archy; and is therefore capable of availing itself of the 
 other abstract sciences, by means of which its complex 
 character may be rendered much more intelligible, as cal- 
 culated and measured phenomena. 
 
THE SCIENCE OF PHENOMENA. 329 
 
 The result of our investigation concerning the pure 
 sciences is that we have arrived at a series of fundamental 
 ideas ; viz. order, number, space, time, substance, motion, 
 combination, and organisation ; several of which have been 
 already worked out and established : but if our view of 
 this subject be correct, there are several yet remaining 
 concerning which much must be done before they can be 
 accepted as rational sciences, as will be readily seen in the 
 following enumeration ; viz. logic, arithmetic, geometry, 
 chronometry, hypostatics, cinematics, enemies, and or- 
 ganics. 
 
330 
 
 CHAP. XII. 
 
 RECAPITULATION AND CONCLUSION. 
 
 Has the Thesis been proved, that the State of Modern Science is un- 
 satisfactory ? Freedom of Discussion necessary for the Advance- 
 ment of Science. There are Sciences of Realities and Sciences of 
 Ideas; Concrete and Formal Sciences: the Data of the former, 
 Facts ; of the latter, Truths. A Trinity in Unity incomprehensible. 
 Dualism the Condition of Nature, of which the Mental Faculties 
 partake ; and are capable, by Consciousness, of apprehending. 
 Phenomenal Knowledge directly perceived as a Monism. The 
 general Character of Science, the Progression of Knowledge in 
 different Ages, analogous to individual Development. Review of 
 the various Sciences. A System of the Sciences. Conclusion. 
 
 SUCH is the evidence by which we have attempted to 
 prove our introductory proposition that, the present 
 state of scientific knowledge is not satisfactory ; that 
 theories, not facts, are the more clamant desiderata of 
 science. How far we have substantiated this charge ; and 
 how far we have been successful in our proposed remedy 
 for this unsatisfactory condition of knowledge, must await 
 the decision of others : the system of the sciences, or 
 philosophy, which has cost us so much thought and toil, 
 " may be only a phantom ; it may prove to be a reality" 
 
 We are buoyed up with the hope of the latter happy 
 consummation of all our labours by the circumstance 
 that the numerous outstanding facts which we have 
 grappled with (all indeed which we could remember dur- 
 
CONCLUDING REMARKS. 331 
 
 ing the investigation,) have all, without a single exception, 
 found a place in our system ; and by a knowledge of their 
 relations thus obtained, have received, if not the true, at 
 least a reasonable explanation. This assertion may excite 
 a smile in those who know, by experience, how easy it is 
 to reduce all things to any standard, by the Procrustean 
 method : we have been from the beginning aware of this 
 tendency of the mind, and have endeavoured to watch 
 carefully against falling into such a fallacy. And yet, 
 notwithstanding all our care, the precaution may have been 
 in vain; for humanum est errare : we appeal therefore to 
 the judgment of others on this subject. 
 f Science has two standards of validity; corresponding 
 in this respect with the dualistic constitution of nature, 
 and with the two-sided character of all natural knowledge. 
 Thus we have sciences of facts and sciences of truths; 
 that is, of realities and of ideas : we can only know material 
 bodies, that is, natural beings or existences, mediately 
 through their attributes which belong to the individual 
 powers that constitute natural beings ; for all such are not 
 distinct and independent existences, but essentially dual- 
 isms of powers. And since each power is a reason- 
 directed force, an efficiency capable of acting according to 
 the law of its innate reason ; force and reason are the in- 
 dissoluble attributes of power, not only co-existent but 
 co-equal : hence it is that facts and truths, though 
 essentially one, may be regarded from different stand- 
 points ; the one as relating to actual forces, manifested as 
 natural realities ; the other relating to the formal reason, 
 or rational principles which are known as abstract ideas. 
 So that when we speak of facts being the objects of the 
 
332 THE PHILOSOPHY OF NATURE. 
 
 physical or material sciences, and of truths as the objects 
 of the mental or formal sciences, it must not therefore be 
 supposed that facts and truths are completely heteroge- 
 neous ; for they are only the two-sided views of one and 
 the same rational idea, which objectively is a real fact, sub- 
 jectively a formal truth. 
 
 A fact may therefore be defined as the conformity of 
 the real to the ideal ; and a truth, as the conformity of 
 the ideal to the real : from which it is evident that these 
 terms express one and the same thing from different points 
 of view. But we must not conceive of them as coming 
 under the head of natural dualisms, which may be formu- 
 lated, according to our archetypal correlation, as 
 
 Fact + truth = fact truth, or verity. 
 
 The association of fact and truth is not a dualism, but 
 relates to a higher constitution than anything in nature 
 which can be definitely known ; it is on the same footing 
 as that of power, which is a unity in diversity, as respects 
 its conjoint and indissoluble attributes of force and reason : 
 neither of which can be conceived of as before or after 
 other ; but as an actual oneness, which may assume to 
 the finite mind a diversity, according to the side on which 
 it is regarded. 
 
 Absolute, or perfect oneness of power, and its attri- 
 butes, imply a trinity, which may be accepted as a re- 
 vealed truth, but cannot be comprehended by the human 
 mind ; for this simple reason, that it has no relation to 
 any of the data of natural knowledge. Man is a part of 
 nature, and, by his peculiar mental endowment, is capable 
 of interpreting the reason in nature: and, therefore, as 
 
CONCLUDING REMARKS. 333 
 
 every natural thing is twofold, a dualism or composition 
 of two kinds of antagonistic (not consentient) powers, can 
 be readily apprehended, and perfectly comprehended. All 
 this is, we conceive, consistent with reason. In the lower 
 development of the understanding, as mere perception, 
 whether that of the brute or of man, all acquired know- 
 ledge is immediate and phenomenal, that is, such know- 
 ledge may be characterised as being that solely of monism; 
 all things are, to a mind so constituted, just as they ap- 
 pear to be, distinct individualities. The brute cannot 
 rise above this conditioned state of knowledge ; thus far, 
 and no farther, is the decree of Deity : and it would be 
 in vain for the brute to thirst after a higher knowledge, if 
 it were possible for it to do so. Man is not restricted to 
 this narrow limitation of knowledge ; he possesses the 
 highest form of that natural understanding which he has 
 in common with the brute, and which may be called 
 common sense; but he also enjoys an extraordinary sense, 
 or mental faculty, of a higher order, by which he is enabled 
 to look below the surface of things, and to acquire a 
 knowledge of the reason in nature. And what does this 
 learning consist in ? It consists in knowing what things are 
 in themselves ; that they are not what they seem to be in 
 their phenomenal oneness, but are composed of various 
 and dissimilar constituents : that this oneness is in fact a 
 diversity in unity, and that this diversity, however great, 
 may be reduced into two distinct and antagonistic parts, 
 which by their union make a binary compound or dualism. 
 The sum total then of all rational knowledge is that all 
 natural bodies are dualisms (not monisms, as the inferior 
 animal intellect apprehends them to be), but the uni- 
 
334 THE PHILOSOPHY OF NATURE. 
 
 fication of two co- existing and opposite powers, an idea of 
 composition which the rational mind is so framed as to 
 understand, which indeed corresponds with its own consti- 
 tution : in short, it is the peculiar property of its attribute, 
 and that is all that can be said for any power. But the 
 knowledge of dualism, the two in one, is the limitation of 
 man's mental acquirements; he frets himself in vain in 
 striving to overflow the shores which bound conditioned 
 knowledge; in vain he grasps at the phantom of the 
 Absolute which tantalises his aspirations after higher 
 knowledge : it is unattainable, for this simple reason that 
 the mind, in the present state of existence, has no faculty 
 capable of compassing a knowledge of a trinity in unity ; 
 such knowledge is too high for mortal ken, it cannot attain 
 to it ; though it may in a more exalted state of existence, 
 when it will know even as it is known. 
 
 We must therefore rest content with the knowledge of 
 the dualistic condition of existence ; a condition which, as 
 already said, is that of all natural bodies : and so far this 
 accords well with our purpose, for a system of the sciences 
 is only concerned with natural knowledge, which must be 
 worked out by the logical faculty of the mind; whilst 
 supernatural knowledge cannot be self-acquired, but must 
 be imparted by divine instruction. 
 
 The dualistic constitution of nature, and the twofold 
 aspect of each of its constituent powers, afford a clue to 
 the character of each individual science, and to the collateral 
 series into which the sciences arrange themselves in the 
 general system. A natural body is a dualism, a unity in 
 diversity, or oneness : and according to the character of its 
 outward appearance, it may be classified in the system of 
 
CONCLUDING REMARKS. 335 
 
 nature; and this descriptive knowledge, or natural history, 
 must needs be the introductory branch of every science, 
 and is attained by aid of the logical method of induction. 
 And, in the second place, a knowledge of the composition 
 of the dualism, shows what it is in itself, and what are the 
 characteristics of its constituents ; a knowledge which is 
 the foundation of the physical or causal branch of each 
 science, by which its various phenomena are capable of 
 being explained. In the acquisition of the first branch of 
 a science, all the objects relating thereto are inductively 
 arranged into a synthetic whole or universal, which must 
 necessarily possess some generic character, by which all 
 its parts may be predicated ; such a character is the fun- 
 damental principle of the science, it is sometimes used as 
 the name or noun- substantive of the science itself, but 
 more correctly this should have reference to the universal 
 and not to its attribute. In the acquisition of the second 
 or physical branch of a science, the immediate subject for 
 consideration is the synthetic whole itself, which by a de- 
 ductive process is analysed into subordinate classes ; and 
 these again into their subalterns, and so on until all its 
 particular parts are developed : each of these parts is 
 a dualism of powers, as much so as the universal itself; but 
 in each, the constituent powers are united in different pro- 
 portions, and it is the knowledge of these different relations 
 that enables us to explain their respective phenomena. 
 
 These are the principles on which the sciences, or sys- 
 tematic knowledge of dualisms, depend : but inasmuch as 
 all the powers which constitute these dualisms may be 
 regarded either on their real or on their ideal side, that is, 
 either as to their potential contents or their rational forms, 
 
336 THE PHILOSOPHY OF NATURE. 
 
 the knowledge derived therefrom must exhibit a correspond- 
 ing difference. The one view will give us forces as the 
 subject-matter of one series of sciences ; and the other, the 
 abstract forms of the reason in nature, for another series of 
 sciences : and it is to this double vision, or consciousness 
 of the mind, which can direct its attention either to the 
 content of its ideas which depend on physical impressions, 
 or to the form of its ideas which are its rational principles, 
 that we are indebted for the two series of sciences, the 
 physical and the formal. Although these series of sciences 
 are so distinct that they cannot be confounded, they are, 
 however, intimately connected ; oftentimes exhibiting 
 most circumstantial correspondencies. This is not sur- 
 prising, since they are so closely related : for, as in 
 natural bodies, the real and ideal are indissolubly con- 
 joined, so that one cannot even exist without the other; 
 so, in the case of the physical and formal sciences, the 
 knowledge of the one is impossible without that of the 
 other. 
 
 We have already endeavoured to show that an objective 
 knowledge of nature must have been first acquired, before 
 the pure sciences could have been constructed : the ideas 
 on which these sciences are founded relate only to know- 
 ledge which lies on the surface of things, which intui- 
 tively apprehended, readily becomes subservient to the 
 logical methods of the rational mind. The contempla- 
 tion of natural bodies, as a diversity in unity, (however 
 crude and imperfect their early classified arrangements 
 must necessarily have been,) must sooner or later have 
 suggested to the mind the abstract notions of multitude 
 and magnitude, together with all their correlative ideas ; 
 
CONCLUDING REMARKS. 337 
 
 and the possibility of their being gathered together into 
 distinct systems. All the abstract sciences of ancient 
 times, logic, arithmetic, and geometry, are essentially 
 phenomenal sciences, corresponding respectively with that 
 oneness which characterises our knowledge of the appear- 
 ance of things. The ancients had, indeed, a clear apper- 
 ception that there is also an inner as well as an outward 
 nature of things ; they hastily formed hypotheses thereon, 
 and put forth divers philosophies, which were intended to 
 acquaint us with the causes of all those physical changes 
 which are manifested as the phenomena of nature. That 
 their failure was signal, is not surprising; for with the 
 exception of some notions, more or less correct, concern- 
 ing bodies in a statical condition, and in a state of motion, 
 they were not prepared to understand the inner nature of 
 things: this requires a previous lengthened investigation, 
 not only concerning the constitution of things, but also of 
 the rational laws by which the constituents are governed 
 in their mutual actions and reactions, resulting in natural 
 phenomena. 
 
 Thus far then we have traced that natural history know- 
 ledge, which is external and objective, and almost intui- 
 tively acquired (being accomplished, indeed, inductively, 
 but by the almost instinctive operation of the logical mind, 
 which compares things as to their similarity or dissimi- 
 larity and arranges them accordingly), but when once 
 acquired it furnishes a variety of abstract ideas, as data 
 for the construction of some pure formal sciences, which 
 for distinction' sake may be called the elementary or mono- 
 formal sciences : their subject-matter is purely simple, as in 
 the case of logic, arithmetic, geometry, and chronometry ; 
 
338 THE PHILOSOPHY OF NATURE. 
 
 which are respectively the sciences of order, number, space, 
 and time. Now such are manifestly pure and simple, or 
 monistic; and not dualistic, as in the case of motion, 
 which is a composition of forces. 
 
 Onward the human intellect advances; it has now 
 acquired a knowledge of nature both on its real and ideal 
 side ; but this knowledge is, in a sense, purely superficial, 
 and only concerns nature in a statical state of rest : it has 
 nothing to do with nature in a dynamical state, it regards 
 not those incessant actions and reactions which produce 
 continual changes in the appearance of things. Nature is 
 indeed a dualism, but ancient science has only, effectively, 
 dealt with it as a congeries of apparent monisms : by means 
 of ancient science, however, a firm footing has been ob- 
 tained, and now the intellectual lever can be applied with 
 good prospect of forcing an entrance into the temple of 
 nature, and unveiling all her mysteries. 
 
 By a reflex action, the mathematical mind turns its 
 attention on that nature from which it derived its know- 
 ledge; and now with logical precision it defines each 
 distinct kind of property by which the various natural 
 bodies are characterised. It investigates, by a searching 
 scrutiny, the changes which bodies undergo in their pro- 
 perties, marks down the varying circumstances under 
 which each kind of property disappears and reappears: 
 the investigation is no longer a vague process of mere 
 observation and record; but each change is calculated, 
 and noted by a definite enumeration ; and also measured 
 and delineated with geometrical precision. 
 
 Such a knowledge of natural phenomena is an aggregate 
 of physical facts, which should furnish sufficient data for 
 
CONCLVDING REMARKS. 339 
 
 the construction of a physical science. The word physics 
 is in continual use ; we scarcely ever discuss any scientific 
 subject without frequently employing this expression: 
 for whenever astronomy, acoustics, optics, and the like are 
 mentioned, we generally conclude by saying, these and 
 all the other physical sciences. The term physics, in 
 ordinary parlance, seems merely to imply that astronomy, 
 optics, and other special and analogous sciences, have 
 something in common, which may be designated as phy- 
 sical : it is only regarded as a convenient bond of union 
 by which they may be held together in one group. This 
 notion, however, is we think anti-scientific, to borrow a 
 phrase from Comte; for, if these several sciences are 
 specific, and have a common term, this can be no other 
 than a generic term : and, consequently, it must logically 
 follow that physics is the generic science, or universal, 
 which includes all the particular physical sciences as 
 species. Whatever may be the difficulty of establishing 
 such a universal science as physics, it cannot be evaded ; 
 for it is an inevitable necessity. 
 
 In reply it may urged that this is a mere metaphysical 
 objection ; and that if accepted it will involve us in a world 
 of abstractions ; that such nice precision of language 
 is superfluous ; that it is sufficient that the conventional 
 use of the word physical is well understood, and very 
 convenient in practice. This and much more might be 
 objected : but it would be more rational, we think, to accept 
 this, and any other philosophical hint, so far as to test its 
 truth; and finding it invalid to state clearly the proof 
 thereof. For the sake of discussing this point, let it be 
 provisionally admitted that physics is a distinct science : 
 
 z 2 
 
340 THE PHILOSOPHY OF NATURE. 
 
 then comes the question, what is it the science of? Before 
 attempting to give an answer, it will be well, in the first 
 place, to call to mind the character of the special sciences ; 
 and then we may possibly gain an insight into that which 
 they all have in common, and which ought to be the 
 subject-matter of physic s. 
 
 Astronomy is the science of celestial bodies or stars : it 
 treats of that form of natural or material bodies, which 
 are of vast magnitude ; acting and reacting on each other 
 by their constituent and antagonistic energies, gravitation 
 and centrifugy, which operate as central forces, functioning 
 in motions of rotation and revolution. 
 
 Molecular physics or micronomy, is the science of mole- 
 cules : it treats of atomic forms, the minima of material 
 bodies, which act and react on each other by their innate 
 condensing and expanding forces of cohesion and heat ; 
 which operate as molecular forces, and function in the 
 various states of matter in all their relations. 
 
 Acoustics and optics are the sciences of vibrating 
 molecules and atoms, material undulations which are not 
 progressive motions, but motions which oscillate within 
 limited spaces; and which result from their component 
 forces acting and reacting on each other, producing the 
 phenomena of sound and light. 
 
 Lastly, polarity, the science of molecules in a state of 
 polar motions, treats of tangential currents formed by a 
 continuous series of polar actions and reactions produced 
 by their constituent and opposite forces, functioning in 
 the phenomena of electricity and magnetism. 
 
 Now, on a survey of all these special sciences, we observe 
 that the objects of each are some form or other of material 
 
CONCLUDING REMARKS. 341 
 
 bodies ; and that the differentiation in each case depends 
 on this form, and the corresponding phase of the acting and 
 reacting forces which are concerned therein. Since material 
 bodies are all dualisms of forces, it is almost superfluous to 
 note that all the different forces which are considered in 
 each physical science, are only various phases of the self- 
 same forces, attraction and repulsion : so that the various 
 motions which these forces produce by acting in a different 
 manner are the physical phenomena which these sciences 
 discourse about ; and all these are at root one and the 
 same, as motions or changes of place ; their various aspects 
 depending on the peculiar methods by which these motions 
 are accomplished. It is, therefore, the object of each 
 special science to treat only of its individual peculiarity : 
 whilst they all have this in common, that their objects are 
 some form or condition of material bodies. 
 
 Guided by these considerations, we have been induced 
 to conclude that there may be such a universal science as 
 that of physics ; that its subject will be that of material 
 bodies generally or matter: and, accordingly, we would 
 define physics to be the science of matter or physical sub- 
 stance. The object of such a science would be to gather 
 together everything relating to material bodies, that is, as 
 far as regards their physical properties. 
 
 In entering on such an undertaking it may seem to be 
 of a more abstract character than it really is. It is true 
 that pure matter, or ether, stands apart from all other 
 bodies, in that it is immediately inappreciable by the senses 
 (which, indeed, to a great extent, is also the case with a 
 permanent gas, such as hydrogen when greatly rarefied), 
 but this does not make it an abstraction ; it is capable of 
 
 z 3 
 
342 THE PHILOSOPHY OF NATURE. 
 
 being known by its phenomena ; and this is as much as we 
 can assert even of visible and tangible bodies. In dealing, 
 therefore, with every kind of material body, there are 
 certain physical properties which are common to them all ; 
 even in the various kinds both of chemical and organic 
 bodies, inasmuch as they are partly material, all such 
 properties are present, but variously modified according to 
 their molecular condition : and in all such cases we can 
 set aside the peculiarities, and only regard those characters 
 which belong to general physics. In this manner we may 
 arrive at a knowledge of various material objects which 
 must be defined; of principles which, as laws, regulate 
 the actions of their constituent forces, and which are ex- 
 pressed as axioms; and, lastly, of postulates which are 
 requisite to explain their modus operandi. i We will en- 
 deavour to illustrate our meaning by a few details. 
 
 Definitions. 
 
 1. Physics is the science or systematic knowledge of 
 matter. 
 
 2. Mattel* is an indissoluble dualism of attractive and 
 repulsive powers, more generally known as physical forces. 
 
 3. Atom, a unit of matter, a minimum quantity of 
 physical forces. 
 
 4. Mass, an aggregation of atoms into a distinct body, 
 a part of universal matter. 
 
 5. Material bodies, masses of various forms. 
 
 6. Properties of matter, weight and volume. 
 
 7. Weight, a definite quantity of attraction directly as 
 the number of atoms. 
 
CONCLUDING REMARKS. 343 
 
 8. Volume,- a variable quantity directly as the amount 
 of repulsion. 
 
 9. Atomic weight, an indefinite minimum of weight, an 
 assumed quantity according to some conventional standard 
 of unity. 
 
 10. Atomic volume, the amount of extension of a single 
 atom. 
 
 11. Density, or specific gravity, a relative quantity, 
 directly as the weight and inversely as the volume. 
 
 12. Capacity, or specific volume, a relative bulk, directly 
 as the volume and inversely as the weight. 
 
 13. Equilibrium, or statical state, that condition of mat- 
 ter, when its physical powers are not only co-existent and 
 opposite, but also co-equal. 
 
 14. Force, or dynamic state, that condition of matter, 
 when one or other of its dualistic powers predominates as a 
 plus or energetic force. 
 
 15. Diffusion, or induction, the progression of a plus 
 force towards the restoration of equilibrium. 
 
 16. Motion, the normal function of matter resulting 
 from the action and reaction of its co-existent and opposite 
 physical forces. 
 
 17. Rest, the constrained state of bodies by a plus 
 resisting force in the directions of all possible motions. 
 
 Postulates. 
 
 Let it be granted that material atoms are compounds 
 of the physical powers, attraction and repulsion. 
 
 And that these forces act on each other tangentially, 
 the one polarly and the other equatorially ; by which con- 
 centric currents are produced at right angles to each other. 
 
 z 4 
 
344 THE PHILOSOPHY OF NATURE, 
 
 Axioms. 
 
 1. Universal matter is a system rotating in perfect 
 equilibrio, depending on the co-equality of its co-existing 
 and opposite forces : hence the law of the conservation of 
 forces. 
 
 2. If parts of this statical whole be added to similar 
 parts, the total is of the same denomination. 
 
 3. If statical parts be taken from statical parts, the re- 
 mainders are statical. 
 
 4. If dynamical parts (that is, portions of matter, the 
 constituent forces of which are unequal), be added to 
 dynamical parts, the sum or aggregate is similar. 
 
 5. If dynamical parts be subtracted from similar parts, 
 the remainders are dynamical. 
 
 6. If statical be added to dynamical parts, the aggregate 
 is dynamical. 
 
 7. If statical be taken from dynamical parts, the re- 
 mainder is dynamical. 
 
 8. If the dynamical state arises from excess of attraction 
 on any given part of universal matter, contraction of 
 volume and increase of density result. 
 
 9. If the dynamical state proceeds from excess of repul- 
 sion, volume is enlarged and specific gravity diminished. 
 
 These axioms have more immediate reference to the 
 condition of the constituent forces; we might have added 
 others applicable to the motions which result from the 
 actions and reactions of these forces ; but we cannot now 
 attempt to exhaust the subject, it is only desired so far to 
 touch thereon as to make our views intelligible. In the 
 above-mentioned definitions, axioms, and postulates, the 
 
CONCLUDING REMARKS. 345 
 
 terms matter and forces have been substituted for sub- 
 stance and causes, the abstract principles of Hypostatics : 
 thus this pure science may be made instrumental in 
 working out the concrete science of physics; just as 
 rational mechanics is applied to astronomy. 
 
 At the same time, we learn the relation which subsists 
 between the concrete and the formal sciences : the one 
 deals with the real side of nature, in which actual forces 
 are concerned, and which function in those tangible and 
 visible changes called physical phenomena; the other with 
 the ideal forms of nature, which interpreted by the mind 
 make known the rational principles and laws of powers 
 according to which they exert their reason-directed forces. 
 A complete knowledge of nature cannot be obtained but 
 by a narrow scrutiny of both sides of the question; we 
 must examine both theraz/and ideal, and then, synthetically 
 uniting them, we complete the knowledge as far as the 
 human mind can reach. This is not a fanciful idea, but 
 in conformity with astronomy, which requires not only 
 to study the concrete science, as to its actual phenomena, 
 and the real forces of gravitation and centrifugy concerned 
 therein, but also to know rational mechanics in order to 
 conjoin the real and ideal ; so in each of the other special 
 physical sciences a similar conjunction must take place. 
 And it will be, we think, also requisite that the sciences of 
 chemistry and biology (which treat of changes which do not 
 come under the head of physics in the restricted sense in 
 which we have used it, as they are not concerned with 
 changes that are motions), should be associated with cor- 
 responding formal sciences, such as rational chemistry or 
 chemics, and rational physiology or organics. 
 
346 THE PHILOSOPHY OF NATURE. 
 
 First attempts in any new field of research must neces- 
 sarily be imperfect; but, if any one has only caught a 
 glimpse of the unknown region, ought he not fearlessly to 
 state what he has seen, or thought he saw, regardless of 
 the derision which may follow the detection of his delu- 
 sion ? There has been too much of this sarcasm used of 
 late ; it is not a scientific spirit ; it may exert an unhappy 
 influence on those who are engaged in the earnest search 
 after truth ; for it is inimical to the candid and unreserved 
 expression of individual experience. History has taught 
 us, that even the most eminent men will stumble into 
 reiterated errors ; and that it has been in the correction of 
 these errors that some of the greatest advances of science 
 have been effected : sometimes these errors have not only 
 been detected, but corrected by the author himself; as 
 witness those remarkable instances of Kepler, which have 
 held him up as a pattern for future inquirers. And if 
 this be the case, the fear of failure need not restrain any 
 one from the candid statement of any well-considered 
 opinion : Magna est veritas, et prevalebit. 
 
 Let us then gather together what has been stated 
 generally concerning the sciences, and strive to reduce them 
 to some arrangement, according to the preceding views. 
 In the first place, the highest generalisation of our know- 
 ledge concerning the universe is, that it is a subordinate 
 system of beings, a class of Ontology, characterised by its 
 objects as dualisms of natural power. That this system of 
 nature, which may be treated of as Cosmology, is co-ordi- 
 nated with another subordinate system, or class of ontology, 
 dualisms of supernatural powers, the knowledge of which 
 may be distinguished as Pneumatology. Both these 
 
CONCLUDING REMARKS. 347 
 
 classes of dualisms may be discriminated ; in the one case as 
 spiritual, and in the other as material bodies : but in both 
 cases they are conditioned beings, not independent and abso- 
 lute, but compositions of forces. Together these classes con- 
 stitute a higher class, or summum genus, of dualistic or con- 
 ditioned beings, which gives the science of ontology ; this 
 is the whole domain of conditioned knowledge: divine 
 knowledge we can only acquire, as taught by revelation ; we 
 cannot understand the trinism or trinity of absolute uncon- 
 ditioned being, and so we cannot connect the highest grade 
 of being, the supreme power, with the system of ontology. 
 
 We are compelled, therefore, to restrict our system of 
 the sciences to that of nature, a subordinate class of the 
 higher system, ontology ; and accordingly we define cos- 
 mology as the science of natural beings or powers, or more 
 simply, as that of nature. 
 
 Now nature affords such a vast field for knowledge, 
 no wonder that ages on ages have passed away without its 
 having hitherto been reduced to one homogeneous system 
 of doctrines : turn which way we will, we are met in 
 every direction by portions only of this system, whose ob- 
 jects are so numerous and interesting, that a life-long 
 study is insufficient for their right comprehension. During 
 these ages, however, thousands on thousands of inquirers 
 have spent their energies in these researches ; and have re- 
 corded their results : at the same time a succession of their 
 coadjutors have toiled to arrange these results ; and to draw 
 therefrom divers rational principles. Time has sped on, 
 and man is still engaged in the same pursuits ; the results 
 of which have always tended to a higher and higher gene- 
 ralisation of knowledge in the several departments of 
 
348 THE PHILOSOPHY OF NATURE. 
 
 nature : and all this inductive pioneering has been a neces- 
 sary preparation for a final result. 
 
 When nature is contemplated, under the present light 
 of accumulated knowledge, we perceive that the most 
 general aspect which it presents to view is that of its phe- 
 nomenal appearance, that is, as it seems to be, outwardly: 
 and in order to make the way ready for a more minute 
 and particular inspection, it is requisite, in the first 
 place, to lay this down as appertaining to all the parts of 
 nature in common. This is not only the most rational 
 plan, but it would seem to be the more natural; for it is 
 that course which the mind has intuitively followed, 
 guided by the innate order of its logical methods. First, 
 then, nature is to be posited as an entirety, as the whole 
 world, or the universe : which first divides itself into the 
 celestial and terrestrial ; and the latter into the subordinate 
 classes of the animate and inanimate. Again these classes 
 unfold themselves respectively into the physical and che- 
 mical ; and into the animal and vegetable kingdoms ; each 
 and all of which may be developed into an almost endless 
 variety of genera and species ; and so by an inverse order 
 of proceeding, if we successively withdraw the most par- 
 ticular and the most extensive of these groups, it may be 
 likened to the removal of each outward zone of a concen- 
 tric sphere, until we at last arrive at the more simple 
 central portion on which all were formed, and which pos- 
 sesses only that substantial character which is common to 
 them all. There are various other ways in which the 
 constitution of nature may be illustrated, as by a branching 
 tree or river : but in whatever way it is viewed, it is one 
 system ; in its genus or universal, a material body ; which 
 
CONCLUDING REMARKS. 349 
 
 is variously differentiated by additional specific properties 
 which render it capable of being arranged according to 
 the principles of classification. 
 
 Thus far we arrive at the knowledge of a system of 
 nature viewed outwardly as a system of realities, of divers 
 natural bodies having distinctive properties ; the causes of 
 which we are not now concerned with ; we know them 
 only as manifested to us by the senses, which testify that 
 they are actual existences. The mind after having long 
 dwelt on this knowledge, becomes aware that this is only 
 a one-sided view which it has taken : and this depends on 
 the very constitution of the rational mind ; for every idea 
 it conceives is knowledge, and each idea has not only a 
 contentful also a form. But long before this knowledge of 
 itself was acquired, the mind by its intuitive functions 
 was conscious that in the system of nature there was not 
 only a hierarchy of realities, but also a system of ideas, 
 which might be viewed apart from realities, and consti- 
 tuted into distinct systems of knowledge. In the adoles- 
 cence of the human intellect, the Greeks with youthful 
 vigour of mind soon turned from material realities to the 
 contemplation of their ideal forms, and in a wonderfully 
 short space of time, for such an undertaking, got possession 
 of those pure abstract ideas which form the ideal side of 
 nature, as far as relate to her external appearances. And 
 on these ideas they constructed the sciences of logic, 
 arithmetic, and geometry, which have come down to us 
 as a most invaluable legacy ; for to these sciences we are 
 indebted in a great measure for the success of modern 
 researches. 
 
 So, then, in the study of outward nature we see that 
 
350 THE PHILOSOPHY OF NATURE. 
 
 two kinds of knowledge may be arrived at : if we regard 
 it only as a system of nature, we have natural history ; if 
 we abstract therefrom only the forms of this system, dis- 
 regarding the realities which constitute its actual contents, 
 then we have a pure system, all the parts of which are 
 merely degrees of order, which is the Science or logic. 
 
 Natural history and logic are universal sciences, which 
 are concerned with the objective side of nature : it has 
 already been suggested in this chapter, that the objective 
 view of nature might be well distinguished from the sub- 
 jective by the respective names of monistic and dualistic; 
 indicating that the former looks at things as they appear 
 to be in their respective individualities, the latter as they 
 are per se beneath the surface, as compositions of forces. 
 
 Natural history subdivides itself into the sciences of the 
 three kingdoms of nature, mineralogy, botany, and zoo- 
 logy, in as far as they are only descriptive and classifica- 
 tory : logic underlies the sciences of arithmetic, geometry, 
 and chronometry ; each of these being respectively the 
 logic of number, of space, and of time. Like the subor- 
 dinate genera and species of natural history, these may 
 be successively formed by differentiation : for in the cal- 
 culations of arithmetic logical processes are necessary, as 
 they are also in the mensurations of geometry, which 
 moreover require the aid of numbers ; and lastly in the 
 functions of chronometry, not only logic, but also the 
 processes of number and space, are also requisite. That 
 is, as the sciences develope themselves in the series of 
 complexity, all the earlier or preceding ones may be 
 rendered subservient to their demonstrations. 
 
 We must not, however, attempt to conceal, that there 
 
CONCLUDING REMARKS. 351 
 
 is not that corresponding conformity between the sub- 
 divisions of these concrete and formal sciences, that is 
 necessary to make our scheme as complete as is desirable : 
 between mineralogy, as far as relates to its subordinate 
 crystallography, or rather to its crystalline forms, and 
 geometry, the correspondence is somewhat satisfactory; 
 but in the case of the other sciences the relationship is 
 very indistinct. The above-mentioned abstract sciences 
 seem to be clearly evolved out of the notions which the 
 multitude, the magnitude, and the successions of na- 
 tural bodies readily suggest to the contemplative mind, 
 and may also even be evolved out of logic itself, as already 
 shown: but we should have liked to find that each 
 subordinate on the real side had its corresponding ideal on 
 the opposite side of each kind of cosmical being. This 
 confused view of the subject shows that there is some- 
 thing awanting to complete the analogy, which holds good 
 in the remaining series of the sciences. 
 
 Thus when we investigate the composition of natural 
 dualisms, that is, when we look beneath the surface of 
 things, we find the real and the ideal in a very distinct 
 antithesis : thus in the universal sciences, we have the 
 concrete phenomenology (not however as yet developed as 
 a distinct science) and the formal hypostatics ; the one 
 treating of the actions and reactions of forces which 
 function in actual phenomena, the other, of the relations 
 of pure causes which by causation eventuate in formal 
 effects. Physics subdivides itself into astronomy, mi- 
 cronomy, acoustics, optics, and polarity, all treating of dif- 
 ferent kinds of motions, and the peculiar phases of physical 
 forces by which they are produced : and opposite to each 
 
352 THE PHILOSOPHY OF NATURE. 
 
 of these we have the subordinate sciences of hypostatics ; 
 viz. rational mechanics or cinematics, with its various 
 methods adapted to the special forms of motion with which 
 they are concerned. And lastly we have chemistry, which 
 treats of those specific forces which seem to be intimately 
 related to attraction, the basis or quantitative constituent 
 of physical substance or matter, a fundamental principle 
 of physics : whilst biology deals with a very different class 
 of specific forces which are related to the other universal 
 principle of physics, repulsion ; as already set forth. 
 
 Here, then, on the real side, the specific powers are 
 correctly evolved out of the universal powers, and their 
 position in the general system clearly defined: and the 
 corresponding sciences related to this subject on the ideal 
 side, though not yet acknowledged and worked out, yet 
 seem to be satisfactorily indicated as rational chemistry, or 
 chemics, and rational physiology, or organics. 
 
 This is a rapid survey of those sciences, which are com- 
 monly called physical or natural, and we will now gather 
 them together in their order. 
 
 The trunk of our tree of knowledge, Ontology, has its 
 roots concealed in absolute being, which the unassisted 
 mind cannot know, as is also the case with one of its two 
 branches : so that human knowledge really begins with 
 Cosmology, the science of corporeal beings. The sub- 
 divisions of the latter rest on our correlation, A + B = AB. 
 One side of this equation is intuitively known as the 
 monistic phenomenon ; the other, as the elements of the 
 dualism, the verce causes, of all actions and reactions : 
 and these opposite sides of Nature give corresponding 
 sciences. 
 
353 
 
 ARBOR SCIENTIARUM. 
 
 ONTOLOGY. 
 The Science of Conditioned Beings. 
 
 PNEUMATOLOGY. COSMOLOGY. 
 
 The Science of Spiritual Beings. The Science of Corporeal Beings. 
 
 1st Division, as Monisms. 
 
 2nd Division, as Dualisms. 
 
 As Real. 
 
 As Ideal. 
 
 NATURAL HISTORY. LOGIC. 
 
 The Science of Nature. The Science. 
 
 MINERALOGY. 
 
 BOTANY. 
 
 ZOOLOGY. 
 
 ARITHMETIC. 
 
 GEOMETRY. 
 
 CHRONOMETRY. 
 
 On the Real Side, as Forces. On the Ideal side/as Rational Causes. 
 
 PHENOMENOLOGY, the Science of 
 Natural Dualisms. 
 
 Subdivisions of. 
 
 1. PHYSICS, the Science of Material 
 
 Bodies, or of Matter. 
 
 a. ASTRONOMY, the Science of Stars, 
 or Celestial Bodies. 
 
 b. MICRONOMY, the Science of Mole- 
 cules. 
 
 e. ACOUSTICS, the Science of Sound. 
 d OPTICS, the Science of Light. 
 e . POLARITY, the Science of Polarised 
 Molecules. 
 
 2. CHEMISTRY, the Science of Chemi- 
 
 cal Bodies. 
 
 3. BIOLOGY, the Science of Living 
 
 Bodies. 
 
 a. Physiology. b. Psychology. 
 
 HYPOSTATICS, the Science of 
 Substance, 
 
 Subdivisions of. 
 
 1. RATIONAL MECHANICS, the Science 
 
 of Motion, treats of 
 
 a. Orbital Motions. 
 
 b. Contractions and Expansions. 
 
 c. Sound-waves') 
 
 , T . , A r Undulations, 
 
 d. Light- waves ) 
 
 e. Polar Motions. 
 
 2. RATIONAL CHEMICS, the Science of 
 
 Combination. 
 
 3. RATIONAL ORGANICS, the Science of 
 
 Organisation. 
 
 A A 
 
354 THE PHILOSOPHY OF NATURE. 
 
 This sketch is confessedly imperfect, still we are in- 
 clined to think that it throws some light on an important 
 subject ; viz. the relationship of the principal sciences, 
 both concrete and pure : it shows that whatever department 
 of nature we make the object of our investigation, whether 
 as to its outward appearance, or to its inner constitution, 
 it will be found to have both a real and ideal side ; and 
 accordingly as we direct our attention to the one or the 
 other, the knowledge obtained must relate either to forces 
 or ideas ; that it must be resolved into either a physical or 
 a formal science. And in order to complete our know- 
 ledge of any concrete subject, it is necessary to apply the 
 abstract science in the illustration of its phenomena. 
 
 Many of the sciences which we have enumerated have 
 several ramifications, which would require lengthened 
 details even for their bare mention ; but this omission is 
 of little consequence, for the position of most of them 
 cannot be mistaken. There is, however, one science which 
 has engaged much attention on the continent, which should 
 not be passed over without notice ; viz. Morphology : if 
 this science be viewed as concrete, related to actual ma- 
 terial bodies, it would furnish a good substitute for the 
 very uncouth term, natural history, and would greatly 
 improve the appearance of the preceding tabular arrange- 
 ment. But it sometimes assumes rather the aspect of a 
 pure science : and if this view were strictly adhered to, 
 the science would approximate very nearly to geometry : 
 this is evident when the morphic forms or figures are those 
 of crystals ; but when extended to organic forms, the 
 case becomes dubious. Still, when we remember that it 
 is only in certain parts of every science that its objects 
 
CONCLUDING REMARKS. 355 
 
 are definite (for at both extremes they are indefinite], it is 
 very possible that no parts of space, as manifested by na- 
 tural bodies, are truly amorphous, that they are always 
 approximations, though these are indefinite. All things 
 considered, however, we are rather disposed to the former 
 opinion, because the term morphology might be used as 
 the science of the outward forms or figures of natural 
 bodies ; the classification of phenomena. 
 
 But in our enumeration there may appear to have 
 been a still greater omission; we have not given a place in 
 the system to the important science of Geology: the reason 
 for so doing is as follows. Our planet is one of the stars, 
 one of the many objects which make up the subject-matter 
 of astronomy: its history is that of an individual star 
 from the period of its origin, by solar fission, to the pre- 
 sent period of its existence. During this lapse of ages, it 
 has undergone a succession of important changes, which in 
 the days of its youth were vast and momentous ; but as it 
 approached maturer years, these changes have settled 
 down to a regular routine, which mark the several stages 
 of its existence. Now, it seems to have attained a good 
 old age : the action of the elements, aided by chemical 
 changes, and the continuous accumulation of organic ex- 
 uvia3, are the same in kind as they have been for many 
 preceding epochs ; but the material degradations and 
 reconstructions are more feeble, and the results corre- 
 spondingly inconsiderable. The study of these changes, 
 the individual history of the earth, forms the subject- 
 matter of geology ; and for the successful prosecution of 
 this interesting research, the physical, chemical, and phy- 
 siological sciences must all render their assistance : it is 
 
 A*A 2 
 
356 THE PHILOSOPHY OF NATURE. 
 
 a vast study, requiring a great range of knowledge ; a 
 science, if it can be so called, of a very complex character. 
 It rather seems to us to be a historical subject, in the 
 illustration of which many sciences are aptly applied : for 
 we cannot discern in it any fundamental principle, which 
 can become the noun-substantive of a distinct science. 
 The earth, as a natural body, has experienced, and con- 
 tinues to experience, a vast variety of changes ; but when 
 we abstract therefrom all the physical, chemical, and 
 organic changes, the result seems to be exhaustive : could 
 we detect one which does not fall within these categories, 
 then we might be able to erect geology into a primary 
 science; but failing this, it can only be a history, like that of 
 any other individual creature, or at best a compound science. 
 
 It is time, however, to draw our subject to a close. 
 We would have gladly entered on the discussion of moral, 
 social, and political topics : but these, as already remarked, 
 are anthropological ; so distinct from physical sciences, 
 that it was deemed expedient to keep them apart. 
 
 In conclusion, we would fain express our hope that we 
 have not laboured altogether in vain ; that the various 
 views put forward on important subjects, if not accepted, 
 may at least be the means of directing attention into new 
 channels : and if so, they cannot fail to render some good 
 service ; for any new direction given to thought is an 
 excellent stimulus for invigorating mental exertion. The 
 frequent antagonism of our opinions to those which now 
 generally prevail, is not favourable for a patient consider- 
 ation : but though our opinions are so directly opposed 
 to others, they have not been adopted hastily ; they have 
 been grounded on natural phenomena, which may, how- 
 
CONCLUDING REMARKS. 357 
 
 ever, have been erroneously interpreted. Such errors 
 have been continually committed; but natural facts are 
 the only source of science ; and, right or wrong, we must 
 persevere in attempting the solution of these problems: the 
 very difficulty of the interpretation arouses the intellect to 
 the greatest exertions ; and no one has the right dogmati- 
 cally to determine what can, and what cannot be accom- 
 plished ; for nature herself is the only limitation of human 
 knowledge. On this subject Lord Bacon has well ob- 
 served, " Homo enim Naturae minister et interpres tantum 
 facit et intelligit, quantum de Naturae ordine, opere, vel 
 mente, observaverit ; nee amplius scit, aut potest. Neque 
 enim ulla3 vires causarum catenam solvere aut perfringere 
 possunt : neque Natura aliter quam parendo vincitur. 
 Itaque intentiones geminaB illa3, humane scilicet scienticR 
 et potentia, vere in idem coincidunt : et frustratio operum 
 maxirne fit ex ignoratione causarum." 
 
 We have endeavoured to show that knowledge and 
 power are not only co-existent, but co-equal : as the one 
 increases or diminishes, so must the other ; for they are 
 the inseparable attributes of the self-same being. All 
 beings are powers, whether simple or compound ; and 
 every power has the attributes of force and reason : without 
 force, reason could not manifest its designs ; and without 
 reason, force would have no law for the regulation of its 
 actions. So that, of a truth, powers are verce causa, not 
 mere brute forces, rioting in indiscriminate licentiousness ; 
 but powers which are a law unto themselves : and that law 
 is the reason in nature, which directs all her forces ; and 
 according to which they function in co-ordinated phe- 
 nomena. In this conclusion, we are in direct antagonism 
 
358 THE PHILOSOPHY OF NATURE. 
 
 to Humboldt, Comte, and some of the most talented men 
 of this country, whom it would be invidious to mention. 
 There was a time of ignorance, they say, when myths and 
 personifications of forces were excusable ; but science has 
 now dispelled all this darkness. " The business of the 
 positive philosophy is, seeing how vain is any research 
 into what are called causes, whether first or final, 
 to pursue an accurate discovery of natural laws, with a 
 view of reducing them to the smallest possible number : to 
 analyse accurately the circumstances of phenomena, and to 
 connect them by the natural relations of succession and 
 resemblance." 
 
 The idea of a law, other than an appointed rule for the 
 regulation of an actual being or power in its operations, is 
 to us inconceivable ; and if there be such powers, which as 
 causes are known by their effects, then must such be, in a 
 sense, personifications ; that is, individual existences. But 
 we must refrain ; our case is now before the scientific 
 world : we repudiate positivism, and the identity of forces ; 
 maintaining that all natural bodies are dualisms of powers ; 
 and that each power is a reason-directed force. 
 
 THE END. 
 
 tONDOK 
 
 PBINTED BY SPOTTISWOODE AND CO. 
 KEW-STKEET SQUAKB 
 
 
 
LIST 
 
 WORKS IN GENERAL LITERATURE 
 
 PUBLISHED BY 
 
 MESSRS. LONGMAN, GREEN, LONGMAN, AND ROBERTS 
 39 PATEBNOSTEE Row, LONDON. 
 
 CLASSIFIED 
 
 N D E X. 
 
 Agriculture and Rural 
 Affairs. 
 
 Bavldcn on Valuing Rents, Ac. - 4 
 Road Legislation - 4 
 CairiTs Prairie Farming - - 
 Cecil's Stud Farm - - - * 
 Hoskyns's Talpa - 
 Loudon's Agriculture - - - 13 
 Low's Elements of Agriculture - ' 
 Morton on Landed Property 
 
 Arts. Manufactures, and 
 Architecture. 
 
 Maunder's Treasury of Knowledge 15 
 " Biographical Treasury 15 
 " Geographical Treasury 15 
 " Scientific Treasury - 14 
 " , Treasury of History - 15 
 " Natural History - - 15 
 Piesse's Art of Perfumery - - 18 
 Pitt's How to Brew-Good Beer - 18 
 Pocket and the Stud 9 
 Pycroft'B English Reading - - 18 
 Rich's Comp. to Latin Dictionary 18 
 Richardson's A rt of Horsemanship 18 
 Riddle's Latin Dictionaries - - 18 
 Roget's English Thesauius - - 19 
 Row-ton's Debater - 19 
 
 Mackintosh's Miscellaneous Works 14 
 " History of England - 14 
 M'Culloch'sGeographicalDictionary 14 
 Maunder's Treasury of History - 15 
 Merivale's History of Rome - - 15 
 " Roman Republic - - 15 
 Milner's Church History - - 15 
 Moore's (Thomas) Memoirs, &c. - 16 
 Mure's Greek Literature - 16 
 Normanby's Year of Revolution - 17 
 Perry's Franks ... -17 
 Porter'* Knights of Malta - - 18 
 Raikes's Journal - - - - 18 
 Kiddle's Latin Lexicon - 18 
 Rogers's Essays from Edinb. Reviewl9 
 
 Brande's Dictionary of Science,&c. 4 
 " Organic Chemistry- - 4 
 Cresy's Civil Engineering - - 
 
 Simpson's Handbook of Diuing - 20 
 Thomson 's Interest Tables - - 23 
 Webster's Domestic Economy - 24 
 Willich's Popular Tables - - 24 
 Wilmot's Blackstone - - - 24 
 
 Roget's English Thesaurus - - 19 
 SchimmelPennincl's Memoirs of 
 PortRoval ... 19 
 SchimmelPenninck's Principles of 
 Beauty &- ... 19 
 
 Gwilt's F.ncyclo. of Architecture - 8 
 Harford's Plates Irom M. Angelo - 
 Humphreys's Parable* Illuminated 1 
 Jameson's Saints and Martyr* - 1 
 " Monastic Orders - -11 
 " l.pgends of Madonna - 11 
 " Commonplace-Book - 11 
 Konig's Pictoual Life of Luther - c 
 Loudon's Rural Architecture - 13 
 MacDomgall's Campaigns of Han- 
 nibal 
 MacDougall's Theory of War - M 
 Moseley's Engineering - - - \\ 
 Piesse's Art of Perfumery - - 18 
 Richardson's Art of Horsemanship II 
 Scoffern on Projectiles, &c. - - 19 
 Steam- Engine,by the Artisan Club 4 
 Ure's Dictionary of Arts, &c. 
 
 Biography. 
 
 Arago's Lives of Scientific Men - 
 Baillie's Memoir of Bate 
 Brialmont's Wellington 
 
 Botany and Gardening. 
 
 Hassall's British Freshwater AUse 9 
 Hooker's British Flora - - " - 9 
 " Guide to Kew Gardens - 9 
 Lindley's Introduction to Botany 13 
 Synopsis of the British 
 Flora - - - - 13 
 " Theory of Horticulture - 13 
 Loudon'sHortusBritannicus - 13 
 " Amateur Gardener - 13 
 " Trees and Shrubs - - 1! 
 " Gardening - - - 13 
 " Plants - 13 
 Pereira's Materia Medica - - 17 
 Rivera's Rose-Amateur's Guide - 19 
 Watson's Cybele Britannica - 24 
 Wilson's British Mosses - - 24 
 
 Chronology. 
 
 Brewer's Historical Atlas - 4 
 
 Schmitz's History of Greece - 19 
 Southey's Doctor - - - 21 
 Stephen's Ecclesiastical Biography 21 
 " Lectures on French History 21 
 Sydney Smith's Works - - - 20 
 Lectures - - 21 
 " Memoirs - - 2C 
 Taylor's Loyola - - 21 
 " Wesley - 21 
 Thirlwall's History of Greece - 23 
 Turner's Anglo Saxons - - 2-' 
 Uwins's Memoirs - - 23 
 Vehse's Austrian Court - - 23 
 Wade's England's Greatness - 2J 
 Young's Christ of History - - 24 
 
 Geography and Atlases. 
 
 Brewer's Historical Atlas 4 
 Butler's Geography and Atlases - 5 
 Cabinet Gazetteer - - - - 5 
 Johnston's General Gazetteer - 11 
 M'Culloch's Geographical Dictionary 14 
 
 Bunting's (Dr.) Life - 
 Crosse'8( Andrew) Memorials - 
 Green's Princesses of England - 6 
 Harford's Life of Michael Angelo - t 
 Lardner's Cabinet Cyclopaedia - 12 
 Marshman's Life of Carey, Marsh- 
 man, and Ward - - - li 
 Maunder's Biographical Treasury- It 
 Morris's Life of Becket - - J 
 Mountain's (Col.) Memoirs - - 16 
 
 Haydn's Beatson's Index - 9 
 Jaquemet's Chronology - - 11 
 " Abridged Chronology - 11 
 Nicolas's Chronology of History - 12 
 
 Commerce and Mercantile 
 Affairs. 
 
 Gilbart's Logic of Banking - 8 
 " Treatise on Bankin<* 8 
 
 Murray 's Encyclo. of Geography - 16 
 Sharp's British Gazetteer - - 20 
 
 Juvenile Books. 
 
 Amy Herbert - 20 
 CleveHall ----- 20 
 Earl's Daughter (The) - 20 
 Experience of Life - - 20 
 
 BttiMlr* Memoir* of Moot* - - 16 
 
 (Dr.) Mezzofanti - - 19 
 
 Lorimer'sYoui g Master Mariner 13 
 M'Culloch's Commerce & Navigation 14 
 
 Hewitt's Boy's Country Book - 10 
 " (Mary) Children's Year - 10 
 
 Southey's Life of Wesley - - 21 
 Stephen's Ecclesiastical Biography 21 
 Strickland's Queens of England - 21 
 Sydney Smith's Memoirs - - 21 
 Symond's( Admiral) Memoirs - 21 
 
 Tooke's History of Piices - 23 
 
 Criticism, History, and 
 Memoirs. 
 
 Katharine Ashton - 20 
 Laneton Paisona^e - - 20 
 Margaret Percival - - 20 
 Piesse's Chvmical, Natural, and 
 Physical Magic - - 18 
 
 << Wesley - - - - 21 
 Uwinn's Memoirs - - - - 2; 
 Waterton'e Autobiography & Essays 24 
 
 Books of General Utility. 
 
 Acton's Bread-Book ... 3 
 " Cookery 3 
 Black's Treatise on Brewing - 4 
 Cabinet Gazetteer- - - 5 
 Lawyer - - 5 
 Cust's Invalid's Own Book - 7 
 Hints on Etiquette - - 9 
 Hudson's Executor's Guide - 1( 
 " on Making Wills - 10 
 Kesteven's Domestic Medicine - 12 
 Lardner's Cabinet Cyclopaedia - 12 
 Loudon's Lady's Country Compa- 
 
 Brewer's Historical Atlas - - - 
 Bunsen's Ancient Egypt 
 " Hippolytus - 
 Chapman's Gustavus Adolphus 
 Conybeare and Howson's St. Paul 
 Connolly's Sappers and Miners - 
 Crowe's History of France - 
 Frazer's Letters during the Penin- 
 sular and Waterloo Campaigns 8 
 Gleig's Essays 8 
 Guruey's Historical Sketches - 8 
 Hayward's Essays 9 
 Herschel's Essavs and Addresses - 9 
 Jeffrey's (Lord) Essays - - 11 
 Kemble's Anglo-Saxons - - 11 
 Lardner's Cabinet Cyclopedia - 12 
 Macaulay's Crit. tnd Hist. Essays 13 
 History of England - 13 
 
 Medicine, Surgery, &c. 
 
 Brodie's Psychological Inquiries - ."> 
 Bull's Hints to Mothers - 
 " Managementof Children - 
 " en Blindness 
 Copland's Dictionary of Medicine - 
 Cust's Invalid's Own Book - 
 Holland's Mental Physiology 
 Medical Notc-s <nd Reflect. 
 Kesteven's Domestic Medicine - 12 
 Pereira's Materia Medica - - 17 
 Richardson's Cold- Water Cure - 18 
 Spencer's Psychology - - - 21 
 Todd's Cyclopaedia of Anatomy 
 
 
 
 and Phjsiolugy - - - 21 
 
2 CLASSIFIED INDEX TO GENERAL CATALOGUE. 
 
 Miscellaneous and General 
 Literature. 
 
 Bacon's (Lord) Works - - - 3 
 
 Ivors ; or, the Two Cousins - 20 
 Jameson's Sacred Legends - - 11 
 " Monastic Legends - - 11 
 " Legendsof the Madonna 11 
 
 Peschel's Elements of Physics 
 Phillips'* Mineralosrv - ' 
 " Guide to Geology - - ', 
 Powell's Unity of Worlds' - - ' 
 
 Defence of Eclipse of Faith 7 Lectures on Female Em- 
 
 Smee's Electro- Metallurgy - - 1 
 
 De For, blanque on Army Adminis ployment 11 
 t ration - - - 7 , Jeremy Taylor's Works - - - 11 
 Eclipse of Faith - - - - 7 ; Katharine Ashton - - 20 
 
 Steam Engine (The) - - - 
 Webb's Celestial Objects for Com- 
 mon Telescopes - - - 2 
 
 Fischer's Bacon and Realistic Pki- Konig's Pictorial Life of Luther - 8 
 
 
 losophv ----- 7 Laneton Parsonage - - 20 
 
 
 Greathed's Letters from Delhi - 8 
 Greyson's Select Correspondence - 8 
 
 Letters to my Unknown Friends 13 
 Lyra Germanica 5 
 
 Rural Sports. 
 
 Gurney'* Evening Recreations - 8 
 Hassall's A dulterations Detected,&c. 9 
 
 Maguire's Rome - 14 
 Margaret Percival - 20 
 
 Baker's Rifle and Hound in Ceylon ' 
 
 Haydn ' Book of Dignities - - 9 
 
 Marshman'sSframpore Mission - 14 
 
 Cecil's Stable Practice - - - 
 
 Holland's Mental Physiology - 9 
 
 Martineau's Christian Life - - 14 
 
 " Stud Farm - - f 
 
 Hooker's Kew Guide - - - 9 
 Howitt's Rral Life of England - 10 
 " Visi tsto RemarkablePlaces 10 
 
 " Hymns - - - 14 
 
 ' Studies of Christianity 14 
 Merivale's Christian Records - 15 
 
 Davy'sFishing Excursions, 2 Series 7 
 Ephemera on Angling 7 
 
 Jameson's Commonplace-Book - 11 
 Last of the Old Squires - - 17 
 
 Milner's Church of Christ - - 15 
 Moore on the Use of the Body - 16 
 
 Frepman and Salvin's Falconry - ! 
 Hawker's Young Sportsman - - 
 
 Letters of a Betrothed - - - 13 
 
 " " Soul and Body - 16 
 
 The Hunting-Field - - - f, 
 
 Macaulay's Speeches - 13 
 Mackintosh's Miscellaneous Wons 14 
 
 " 's Man and his Motives - 16 
 Morning Clouds - 16 
 
 Idle's Hints on Shooting - - I 1 
 Pocket and the Stud - i 
 
 Martineau's Miscellanies - - 14 
 Pycroft's English Reading - 1! 
 
 Neale's Closing Scene - 16 
 Pattison's Earth and Word - - 17 
 
 Practical Horsemanship - - t 
 Pycroft's Cricket Field - - - It 
 
 Rich's Comp. to Latin Dictionary I! 
 
 Powell's Christianity without Ju- 
 
 Richardson's Horsemanship - - It- 
 
 Riddle's Latin Dictionaries - - 18 
 Rowton's Debater - - - 1! 
 
 daism - 18 
 " Order of Nature - - 18 
 
 Ronalds' Fly-Fisher's Entomology 1: 
 Stable Talk and Table Talk - - ( 
 
 Sir Roeer De Coverley - - - 20 
 
 Readings for Lent ... 20 
 
 Stonehenge on the D<g - - - 2i 
 
 Southey's Doctor, &c. - - - 21 
 
 " Confirmation - - 20 
 
 " on the Greyhound 2! 
 
 Spencer's Essays *"** 
 
 Robinson's Lexicon to the Greek 
 
 The Stud, for Practical Purposes - '. 
 
 Stow's Training System - - *1 
 
 Testament - - - - - 19 
 
 
 Thomson's Laws of Thought - 23 
 
 Self-Examination for Confirmation 20 
 
 
 Trevelyan on the Native Languages 
 
 Sewpll's History of the Early 
 Church - - - - 20 
 
 
 Willich's Popular Tables - - 24 
 Yonge's English-Greek Lexicon - 24 
 " Latin Gradus - - 24 
 
 Sinclair's Journey of Life - - 20 
 Smith's (Sydney) Moral Philosophy 21 
 (G.) Wesleyan Methodism 20 
 
 Veterinary Medicine, &c. 
 
 Cecil's Stable Practice - - 6 
 u Stud Farm f 
 
 Zumpt's Latin Grammar - - 24 
 
 Natural History in general . 
 
 " (J.) St. Paul's Shipwreck - 20 
 Southey's Life of Wesley - - 21 
 Stephen's Ecclesiastical Biography 21 
 Taylor's Loyola - 21 
 
 Hunt's Horse and bis Master - 11 
 Huntmg-Field(The) - ! 
 Miles's Horse-Shoeing - - - if, 
 " on the Horse's Foot - - If. 
 
 Agaseiz on Classification 3 
 Callow's Popular Conchology - 6 
 Ephemera's Book of the Salmon - 7 
 Garratt's Marvels of Instinct - 8 
 Gosse's Natural History of Jamaica 8 
 Kirby and Spence's Entomology - 12 
 Lee's Elements of Natural History 12 
 
 " Wesley - - - 21 
 Theologia Germanica 5 
 Thumb Bible (The) - - 23 
 Ursula 20 
 Young's Christ of History - - 24 
 "' Mystery - 24 
 
 Pocket and the Stud . l< 
 Practical Horsemanship - - I 1 
 Richardson's Horsemanship - U 
 Stable Talk and Table Talk . - 'J 
 Stonehenge on the Dog - -. -21 
 Stud (The) - - - - '-i 
 
 Youatt's Work on the Dog - -21 
 
 Maunder's Natural History - - 15 
 
 
 Youatt's Woik on the Horse - 2? 
 
 Morris's Anecdotes in Natural 
 History 16 
 
 
 
 Quatrefages' Naturalist's Rambles 18 
 
 Poetry and the Drama. 
 
 
 Stonehenge on the Dog - - 21 
 Turton'sShells oftheBritishlslands 23 
 
 Aikin's (Dr.1 British Poets - - 3 
 
 Voyages and Travels. 
 
 Van der Hoeven's Zoology - -23 
 
 (t P <a 
 
 Baker's Wanderings in Ceylon - :; 
 
 Waterton's Essays on Natural Hist. 24 
 Youatt's Work on the Dog - - 24 
 
 Baillie's (Joanna) Poetical Works 3 
 
 Earth's African Travels - 4 
 Burton's East Africa - ,<> 
 
 Youatt's Work on the Horse - 24 
 
 L. E. L.'s Poetical Works - 13 
 
 " Medina and Mecca - - !, 
 
 1-Volume Encyclopaedias 
 and Dictionaries. 
 
 Linwood's Anthologia Oxoniensia - 13 
 Lyra Germanica 5 
 Macaulav's Lays of Ancient Rome 14 
 Mac Donald's Within and Without 14 
 
 Domenech's Texas 7 
 " Deserts of North America 7 
 Firstlmpressions of the New World 7 
 Forester's Sardinia and Corsica - '< 
 
 
 
 HinchlifP* Travels in the Alps - !' 
 
 Blaine's Rural Sports - - - 4 
 Brande's Science, Literature, and Art 4 
 Copland's Dictionary of Medicine - 6 
 Cresy's Civil Engineering 5 
 
 Montgomery's Poetical "Worki - 15 
 Moore's Poetical Works - - 16 
 " Selections (illustrated) - 16 
 (f Lalla Rookh - - - 16 
 
 Hewitt's Art-Student in Munich - 1" 
 " (W.) Victoria - - -10 
 Hue's Chinese Empire - - - 1 ) 
 Hudson and Kennedy's Mont 
 
 Gwilt's Architecture - 8 
 
 
 Blanc - - - - - V 1 
 
 Johnston's Geographical Dictionary 11 
 Loudon's Agriculture - 13 
 " Rural Architecture - 13 
 
 " Irish Melodies - - - 16 
 " National Melodies - - 16 
 Sacred Songs (with Music) 16 
 
 Humboldt's Aspects of Nature - i'l 
 Hutchinson's Western Africa - 11 
 Kane's Wanderings of an Artist - 1 
 
 " Gardening - 13 
 " Plants - 13 
 " Trees and Shrubs - - 13 
 M'Culloch'sGeographicalDictionary 14 
 
 Shakspeare, by Bowdler - - 19 
 Southey's Poetical Works - - 21 
 Thomson's Seasons, illustrated - 23 
 
 Lady's Tour round Monte Hosa - J 
 M'Clure's North- West Passage - 1, 
 MacDoue,all'sVoyageofthe.Ke*<?'ui!e 1 
 Minium's New York to Oeihi - 1, 
 
 " Dictionary of Commerce 14 
 Murray's Encyclo. of Geography - 16 
 
 
 Mollhausen's Journey to the Shores 
 of the Pacific - - - - 1,", 
 
 Sharp's British Gazetteer - - 20 
 
 
 Oshorn's Quedah - - - - 1" 
 
 Ure's Dictionary of Arts, &c. - - 23 
 Webster's Domestic Economy - 24 
 
 The Sciences in general 
 and Mathematics. 
 
 Peaks, Passes, and Glaciers - 17 
 Scherzer's Central America - - ]! 
 Senior's Journal in Turkey and 
 
 Religious & Moral Works. 
 
 Afternoon of Life 3 
 Amy Herbert - - - - 20 
 
 Arago's Meteorological Essays - 3 
 " Popular Astronomy - - 3 
 Bourne's Catechism of Steam- 
 
 Greece ----- if) 
 Snow's Tierra del Fuego - - 21 
 Tennent's Ceylon - 21 
 Von Tempsky's Mexico - - C!i 
 
 Bloomfield'sGreekTestament - 4 
 Bunyan's Pilgrim's Progress - 5 
 Calvert's Wife's Manual - 6 
 Catz and Farlie's Moral Emblems 6 
 
 Engine - 
 Boyd's Naval Cadet's Manual 
 Brand_e's Dictionary of Science, Ac. 
 " Lectures on Organic Chemistry 
 
 Wanderings in Land of Ham - 2:1 
 Weld's Vacations in Ireland- - 24 
 " Pyrenees - - - - 2i 
 " United States and Canada- 21 
 
 Cleve Hall ----- 20 
 
 Conington's Chemical Analysis - 
 
 
 Conybeare and Howson's St. Paul 6 
 
 Cresy's Civil Engineering 
 
 
 Cotton's Instructions in Christianity 6 
 Dale's Domestic Liturgy - 7 
 Defence of Eclipse of Faith - - 7 
 Earl's Daughter (The) - - - 20 
 
 De la Rive's Electricity 
 Grove's Correla. of Physical Forces 
 Herschcl's Outlines of Astronomy 
 Holland's Mental Physiology - 9 
 
 Works of Fiction. 
 
 Connolly's Romance of the flanks '. 
 
 Eclipse oM'aith - - - 7 Hum boldt's Aspects of Natur - 10 
 
 Cruiks.hank'8 Fals-aff - - - 7 
 
 Englishman's Greek Concordance 7 i " Cosmos - 10 
 
 Hwitt's Tallangetta - - - 1< 
 
 " Heb.&Chald. Concord. 7 I Hunt OB Light - 11 
 
 Mildred Norman - - - - ir> 
 
 Experience (The) of Life - - 20 
 
 Lardner's Cabinet CjFcloptBdia - 12 
 Marcet's (Mrs.) Conversations - 14 
 
 Moore s Epicurean - - - 1'i 
 Sewell's Uifula - - - - 2 
 
 Harrison's Light of the For? - 
 Home's Introduction to Scriptures 10 
 
 Morcll's Elements of Psychology - 16 
 Moseley'sEngineeringA Architecture 16 
 
 Sir Roger De Coverley - - - 2> 
 Sketches (The), Three Tales - 2' 
 
 " Abridgment of ditto - 10 
 Hue's Christianity in China - - 10 
 Humphrcys's Parables Illuminated 11 
 
 Ogilvie's Master- Builder's Plan - 17 
 Owen'* Lectweon Comp. Anatomy 17 
 Pereira on Polarised Light - - 17 
 
 Southey's The Doctor *c. - - 21 
 Trollope's Barchester Towers - 2" 
 " Warden - - - 2! 
 
ALPHABETICAL CATALOGUE 
 
 of 
 
 NEW WORKS and NEW EDITIONS 
 
 PUBLISHED Bl* 
 
 MESSES. LONGMAN, GKREEN, LONGMAN, AND EGBERTS, 
 
 PATERNOSTER ROW, LONDON. 
 
 Miss Acton's Modern Cookery for Private 
 
 Families, reduced to a System of Easy Prac- 
 tice in a Series of carefully-tested Receipts, 
 in which the Principles of Baron Liebig and 
 other eminent Writers have been as much as 
 possible applied and explained. Newly-re- 
 vised and enlarged Edition ; with 8 Plates, 
 comprising 27 Figures, and 150 Woodcuts. 
 Fcp. 8vo. 7s. 6d. 
 
 Acton's English Bread-Book for Domestic Use, 
 adapted to Families of every grade. Fcp. 
 8vo. price 4s. 6d. cloth. 
 
 The Afternoon of Life. By the Author 
 
 of Morning Clouds. Second and cheaper 
 Edition, revised throughout. Fcp. 8vo. 5s. 
 
 Agassiz. An Essay on Classification. 
 
 By Louis A&ASSIZ. Svo. 12s. 
 Aikin. Select Works of the British 
 
 Poets, from Ben Jonson to Beattie. With 
 Biographical and Critical Prefaces by Dr. 
 AIKIN. New Edition, with Supplement by 
 LUCY AIKIN ; consisting of additional Selec- 
 tions from more recent Poets. Svo. 18s. 
 
 Arago(F.) Biographies of Distinguished 
 
 Scientific Men. Translated by Admiral 
 W. H. SMYTH, D.C.L., F.K.S., &c. ; the Kev. 
 BADEN POWELL, M. A. ; -and EGBERT G-RANT, 
 M.A., F.E.A.S. Svo. 18s. 
 
 Arago's Meteorological Essays. With an 
 Introduction by Baron HUMBOLDT. Trans- 
 lated under the superintendence of Major- 
 General E. SABINE, E.A,, Treasurer and 
 T.P.K.S. Svo. 18s. 
 
 Arago's Popular Astronomy. Translated and 
 edited by Admiral W. H. SMYTH, D.C.L., 
 F.E.S. ; and EGBERT GRANT, M. A., F.E.A.S. 
 With 25 Plates and 358 Woodcuts. 2 vols. 
 Svo, price 2. 5s, 
 
 Arnold. Poems. By Matthew Arnold. 
 FIEST SERIES, Third Edition. Fcp. 8vo. 
 price 5s. 6d. SECOND SERIES, price 5s. 
 
 Arnold. Merope, a Tragedy. By Matthew 
 ARNOLD. With a Preface and an Historical 
 Introduction. Fcp. Svo. 5s. 
 
 Lord Bacon's Works. A New Edition, 
 
 revised and elucidated ; and enlarged by the 
 addition of many pieces not printed before. 
 Collected and edited by EGBERT LESLIE 
 ELLIS, M.A., Fellow of Trinity College, 
 Cambridge ; JAMES SPEDDING, M.A. of 
 Trinity College, Cambridge ; and DOUGLAS 
 DENON HEATH, Esq., Barrister-at-Law, and 
 late Fellow of Trinity College, Cambridge. 
 YoLSo I. to V., comprising the Division of 
 Philosophical Works ; with a copious INDEX. 
 5 yols. Svo. price 4. 6s. VOL. VI. price 18s. 
 
 %* VOL. VII., completing the Division of 
 Literary and Professional Works, is just ready. 
 
 Joanna Baillie's Dramatic and Poetical 
 
 Works : Comprising the Plays of the Pas- 
 sions, Miscellaneous Dramas, Metrical Le- 
 gends, Fugitive Pieces, and Ahalya Baee; 
 with the Life of Joanna Baillie, Portrait, 
 and Vignette. Square crown Svo. 21s. 
 cloth ; or 42s. bound in morocco by Hayday. 
 
 Baker. The Rifle and the Hound in 
 
 Ceylon. By S. W. BAKER, Esq. New 
 Edition, with 13 Illustrations engraved on 
 Wood. Fcp. Svo. 4s. 6d. 
 
 Baker. Eight Years' Wanderings in Ceylon. 
 By S. W. BAKER, Esq. With 6 coloured 
 Plates. Svo. price 15s. 
 
 Bate Memoir of Capt. W. Thornton 
 
 Bate, E.N. By the Eev. JOHN BAILLIE, 
 Author of " Memoirs of Hewitson," " Me- 
 moir of Adelaide Newton," &c. New 
 Edition ; with Portrait and 4 Illustrations. 
 Fcp. Svo. 5?. 
 
 >, 2 
 
KE v7 WORKS AND NEW EDITIONS 
 
 Earth. Travels and Discoveries in 
 
 North and Central Africa : Being the Jour- 
 nal of an Expedition undertaken under 
 the auspices of Her Britannic Majesty's Go- 
 vernment in the Years 1849 1855. By 
 HENRY BARTH, Ph.D., D.C.L., Fellow of the 
 Royal Geographical and Asiatic Societies. 
 &c. With numerous Maps, Wood Engrav- 
 ings, and Illustrations in tinted Lithography. 
 5 vols. 8vo. 5. 5s. cloth. 
 
 Bayldon's Art of Valuing Rents and 
 
 Tillages, and Claims of Tenants upon 
 Quitting Farms, at both Michaelmas and 
 Lady-Day ; as revised by Mr. DONALDSON. 
 Seventh Edition, enlarged and adapted to the 
 Present Time: With the Principles and 
 Mode of Valuing Land and other Property 
 for Parochial Assessment and Enfranchise- 
 ment of Copyholds, under the recent Acts of 
 Parliament. By EGBERT BAKER, Land- 
 Ageut and Valuer. 8vo. 10s. 6d. 
 
 Bayldon's (R.) Treatise on Road Legis- 
 lation and Management ; with Remarks on 
 Tolls, and on Repairing Turnpike-Roads and 
 Highways. 8vo. 3s. 6d. 
 
 Black's Practical Treatise on Brewing, 
 
 based on Chemical and Economical Princi- 
 ples : With Formulas for Public Brewers, and 
 Instructions for Private Families. New 
 Edition, with Additions. 8vo. 10s. 6d. 
 
 Elaine's Encyclopaedia of Rural Sports ; 
 
 or, a complete Account, Historical, Prac- 
 tical, and Descriptive, of Hunting, Shooting, 
 Fishing, Racing, &c. New Edition, revised 
 and corrected ; with above 600 Woodcut 
 Illustrations, including 20 now added from 
 Designs by JOHN LEECH. In One Volume, 
 8vo. price 42s. half- bound. 
 
 Bloomfield. The Greek Testament, 
 
 with copious English Notes, Critical, Phi- 
 lological, and Explanatory. Especially 
 adapted to the use of Theological Students 
 and Ministers. By the Rev. S. T. BLOOM- 
 FIELD, D.D., F.S.A. Ninth Edition, revised. 
 2 vols. 8vo. with Map, price 2. 8s. 
 
 Dr. Bloomfield's College and School Edition of 
 
 the Greek Testament : With brief English 
 Notes, chiefly Philological and Explanatory. 
 Seventh Edition ; with Map and Index. 
 Fcp. 8vo. 7s. 6d. 
 
 Dr. Bloomfield's College and School Lexicon 
 to the Greek Testament. New Edition, 
 carefully revised. Fcp. 8vo. price 10s. 6d. 
 
 Bourne. A Treatise on the Steam- 
 
 Engine, in its Application to Minee, Mills, 
 Steam-Navigation, and Railways. By the 
 Artisan Club. Edited by JOHN BOURNE, C.E. 
 New Edition ; with 33 Steel Plates and 349 
 Wood Engravings. 4to. price 27s. 
 
 Bourne's Catechism of the Steam - Engine 
 in its various Applications to Mines, Mills, 
 Steam-Navigation, Railways, and Agricul- 
 ture : With Practical Instructions for the 
 Manufacture and Management of Engines 
 of every !class. Fourth Edition, enlarged ; 
 with 89 Woodcuts. Fcp. 8vo. 6s. 
 
 Boyd. A Manual for Naval Cadets. 
 
 Published with the sanction and approval 
 of the Lords Commissioners of the Admi- 
 ralty. By JOHN M'NEILL BOYD, Captain, 
 R.N. With Compass-Signals in Colours, 
 and 236 Woodcuts. Fcp. 8vo. 10s. 6d. 
 
 Brande. A Dictionary of Science, Lite- 
 rature, and Art : Comprising the History, 
 Description, and Scientific Principles of 
 every Branch of Human Knowledge ; with 
 the Derivation and Definition of all the 
 Terms in general use. Edited by W. T. 
 BRANDE, F.R.S.L. and E. ; assisted by DE. 
 J. CATTYIK. Third Edition, revised and cor- 
 rected ; with numerous Woodcuts. 8vo. 60s. 
 
 Professor Brande's Lectures on Organic 
 
 Chemistry, as applied to Manufactures ; 
 including Dyeing, Bleaching, Calico-Print- 
 ing, Sugar-Manufacture, the Preservation 
 of Wood, Tanning, &c. ; delivered before the 
 Members of the Royal Institution. Edited 
 by J. SCOFFERN, M.B. Fcp. 8vo. with 
 Woodcuts, price 7s. 6d. 
 
 Brewer. An Atlas of History and Geo- 
 graphy, from the Commencement of the 
 Christian Era to the Present Time : Com- 
 prising a Series of Sixteen coloured Maps, 
 arranged in Chronological Order, with Illus- 
 trative Memoirs. By the Rev. J. S. BKEWER, 
 M.A., Professor of English History and 
 Literature in King's College, London. 
 Second Edition, revised and corrected. 
 Royal 8vo. 12s. 6d. half-bound. 
 
 Brialmont. The Life of the Duke of 
 
 Wellington. From the French of ALEXIS 
 BRIALMONT, Captain on the Staff of the 
 Belgian Army : With Emendations and 
 Additions. By the Rev. a. R. GLEIG, M.A., 
 Chaplain- General to the Forces and Pre- 
 bendary of St. Paul's v With Maps, Plans 
 of Battles, and Portraits. VOLS. I. and II. 
 8vo. 30s. 
 
 The THIRD and FOURTH VOLUMES (com- 
 pletion) are now in the press, and will take 
 up the history of the Duke from the Battle of 
 Waterloo, representing him as an Ambassador, 
 as n Minister, and as a Citizen. 
 
PUBLISHED BY LONGMAN, GREEN, AND CO. 
 
 Brodie. Psychological Inquiries, in a 
 
 Series of Essays intended to illustrate the 
 Influence of the Physical Organisation on 
 the Mental Faculties. By Sir BENJAMIN C. 
 BEODIE, Bart. Third Edition. Fcp.Svo. 5s. 
 
 Dr. Thomas Bull on the Maternal Ma- 
 nagement of Children in Health and Disease. 
 New Edition. Fcp. 8vo. 5s. 
 
 Dr. Bull's Hints to Mothers on the Manage- 
 ment of their Health during the Period of 
 Pregnancy and in the Lying-in Room : With 
 an Exposure of Popular Errors in connexion 
 with those subjects, &c. ; and Hints upon 
 Nursing. New Edition. Fcp. 8vo. 5s. 
 
 Dr. Bull's Work on Blindness, entitled 
 
 the Sense of Vision Denied and Lost. Edited 
 by the Rev. B. G-. JOHNS, Chaplain of the 
 Blind School, St. George's Fields. With a 
 brief Introductory Memoir of the Author 
 by Mrs. BULL. Fcp. 8vo. 4s. 6d. 
 
 Bunsen. Christianity and Mankind, 
 
 their Beginnings and Prospects. By 
 Baron C. C. J. BUNSEN, D.D., D.C.L., D.Ph. 
 Being a New Edition, corrected, remodelled, 
 and extended, of Hippolytus and his Age. 
 7 vols. 8vo. 5. 5s. 
 
 V This Edition is composed of three distinct worki, 
 which may be had separately, as follows : 
 
 1. Hippolytus and his Age; or, the Beginnings and 
 Prospects of Christianity. 2 vols. 8vo. price 1. 10s. 
 
 2. Outline of the Philosophy of Universal History ap- 
 plied to Language and Religion: Containing an Ac- 
 count of the Alphabetical Conferences. 2 vols. 8vo. 
 price 1. 13s. 
 
 3. Analecta Ante-Xicseua. 3 rols. 8ro. price 2. 2s. 
 
 Bunsen. Lyra Germanica. Translated 
 from the German by CATHERINE WINK- 
 WOKTH. fifth Edition of the FIBST SEEIES, 
 Hymns for the Sundays and chief Festivals 
 of the Christian Year. New Edition of the 
 SECOND SEEIES, the Christian Life. Fcp. 
 8?o. price 5s. each Series. 
 
 HYMNS from Lyra Germanica 18mo. Is. 
 
 %* These selections of German Hymnn have been made 
 from collections published in Germany by Baron BUSEK; 
 and form companion volumes to 
 
 Theologia Germanica: Which setteth forth 
 many fair lineaments of Divine Truth, and 
 saith very lofty and lovely tlnngs touching 
 a Perfect Life. Translated by SUSANNA 
 WINKWOKTH. With a Preface by the Rev. 
 CHAELES KINGSLKY ; and n Letter by Baron 
 BUNSEN. Third Edition. Fcp. 8vo. 5s. 
 
 Bunsen. Egypt's Place in Universal 
 
 History : An Historical Investigation, in 
 Five Books. By Baron C. C. J. BUNSEN, 
 D.D., D.C.L., D.Ph. Translated from the 
 German by C . H. COTTBELL, Esq., M.A. 
 With many Illustrations. VOL. I. 8vo. 28s. j 
 VOL. II. price 30s. ; and VOL. III. price 25s. 
 
 Bunting. The Life of Jabez Bunting, 
 
 D.D. : With Notices of contemporary Per- 
 sons and Events. By his Son, THOMAS 
 PEECIVAL BUNTING. In Two Volumes. 
 VOL. I. with Two Portraits and a Vignette, 
 in post 8ro. price 7s. 6d. cloth ; or (large 
 paper and Proof Engravings) in square crown 
 8vo. 10s. 6d. 
 
 Bunyan's Pilgrim's Progress: With a 
 
 Preface by the Rev. CHAELES KINGSLEY, 
 Kector of Eversley ; and about 120 Illus- 
 trations engraved on Steel and on Wood 
 from Original Designs by Charles Bennett. 
 Fcp. 4to. price 21s. cloth, gilt edges. 
 
 Bishop Butler's General Atlas of Modern 
 
 and Ancient Geography; comprising Fifty- 
 two full-coloured Maps ; with complete In- 
 dices. New Edition, nearly all re-engraved, 
 enlarged, and greatly improved. Edited by 
 the Author's Son. Eoyal 4to. 24s. half-bound. 
 
 /The Modern Atlas of 28 full- 
 l coloured Maps. Eoyal 8vo. 
 
 , . price 12s. 
 
 Separately j T Ancienfc Atlas of 24 full . 
 
 r coloured Maps. Royal 8vo. 
 \ price 12s. 
 
 Bishop Butler's Sketch of Modern and 
 
 Ancient Geography. New Edition, tho- 
 roughly revised, with such Alterations intro- 
 duced as continually progressive Discoveries 
 and the latest Information have rendered 
 necessary. Post 8vo. price 7s. 6d. 
 
 Burton. First Footsteps in East Africa ; 
 
 or, an Exploration of Harar. By RICHABD 
 F. BUETON, Captain, Bombay Army. With 
 Maps and coloured Plates. 8vo. 18s. 
 
 Burton. Personal Narrative of a Pil- 
 grimage to El Medinah and Meccah. By 
 RICHAED F. BUETON, Captain, Bombay 
 Army. Second Edition, revised ; with coloured 
 Plates and Woodcuts. 2 vols. crown 8vo. 
 price 24s. 
 
 The Cabinet Lawyer : A Popular Digest 
 
 of the Laws of England, Civil and Criminal ; 
 with a Dictionary of Law Terms, Maxims, 
 Statutes, and Judicial Antiquities ; Correct 
 Tables of Assessed Taxes, Stamp Duties, 
 Excise Licenses, and Post-Horse Duties; 
 Post-Office Regulations j and Prison Disci- 
 pline. 18th Edition, comprising the PuMic 
 Acts of the Session 1858. Fcp. 8vo. 10s. 6d. 
 
 The Cabinet Gazetteer: A Popular Geogra- 
 phical Dictionary of All the Countries of 
 the World. By the Author of The Cabinet 
 Lawyer. Fcp. 8vo. 10s. 6d. cloth. 
 
NEW WORKS AND 1S T EW EDITIONS 
 
 Caird. Prairie Farming in America: 
 
 With Notes by the way on Canada and the 
 United States. By JAMES CAIBD, M.P., 
 Author of "English Agriculture," "High 
 Farming," &c. 16nao. 3s. 6d. 
 
 Calvert. The Wife's Manual ; or, 
 
 Prayers, Thoughts, and Songs on Several 
 Occasions of a Matron's Life. By the Rev. 
 W. CALVEET, M.A. Ornamented from De- 
 signs by the Author in the style of Queen 
 Elizabeth's Prayer-Boolc. Second Edition. 
 Crown 8vo. 10s. 6d. 
 
 Catlow. Popular Concholcgy; or, the 
 
 Shell Cabinet arranged according to the 
 Modern System : With a detailed Account 
 of the Animals, and a complete Descriptive 
 List of the Families and Q-enera of Recent 
 and Fossil Shells. By AGNES CATLOW. 
 Second Edition, much improved ; with 405 
 Woodcut Illustrations. Post 8vo. price 14s. 
 
 Catz and Farlie's Book of Emblems. 
 
 Moral Emblems, from JACOB CATZ and 
 ROBERT FAELIE ; with Aphorisms, Adages, 
 and Proverbs of all Nations. The Illustra- 
 tions freely rendered from designs found in 
 the works of Catz and Farlie, by JOHN 
 LEIGHTON, F.S.A., and engraved under his 
 superintendence. Imperial 8vo. with 60 
 large Illustrations on Wood, and numerous 
 Vignettes and Tail Pieces* 
 
 Cecil. The Stud Farm ; or, Hints on 
 
 Breeding Horses for the Turf, the Chase, and 
 the Road. Addressed to Breeders of Race- 
 Horses and Hunters, Landed Proprietors, 
 and especially to Tenant Farmers. By 
 CECIL. Fcp. 8vo. with Frontispiece, 5e. 
 
 Cecil's Stable Practice ; or, Hints on Training 
 for the Turf, the Chase, and the Roadj 
 with Observations on Racing and Hunt- 
 ing, Wasting, Race-Riding, and Handi- 
 capping : Addressed to Owners of Racers, 
 Hunters, and other Horses, and to all who 
 are concerned in Racing, Steeple- Chasing, 
 and Fox- Hunting. Second Edition. Fcp. 
 
 8vo. with Plate, price 5s. half-bound. 
 
 Chapman. History of Gustavus Adol- 
 
 phus and of the Thirty Years' War up to the 
 King's Death : With some Account of its 
 Conclusion by the Peace of Westphalia, in 
 1648. By B. CHAPMAN, M.A., Vicar of 
 Letherhead. 8vo. with Plans, 12s. 6d. 
 
 onhigton. Handbook of Chemical 
 
 Analysis, adapted to the Unitary System of 
 Notation. By F. T. CONINGTON, M.A., 
 F.C.S. Post 8vo. 7s. 6d. Also Tables of 
 Qualitative Analysis, designed as a Com- 
 panion to the Handbook, price 2s. 6d. 
 
 Connolly. The Romance of the Banks ; 
 
 or, Anecdotes, Episodes, and Social Inci- 
 dents of Military Life. By T. W. J. 
 CONNOLLY, Quartermaster of the Royal 
 Engineers. 2 vols. 8vo. 21s. 
 
 Connolly's History of the Royal Sappers and 
 Miners : Including the Services of the Corps 
 in the Crimea and at the Siege of Sebastopol. 
 Second Edition, revised and enlarged ; with 
 17 coloured plates. 2 vois. 8vo. price 30s. 
 
 Conybeare and Howson. The Life and 
 
 Epistles of Saint Paul : Comprising a com- 
 plete Biography of the Apostle, and a 
 Translation of his Epistles inserted in 
 Chronological Order. By the Rev. W. J. 
 CONTBEAEE, M.A. ; and the Rev. J. S. 
 HOWSON, M.A. Third Edition, revised and 
 corrected ; with several Maps and Wood- 
 cuts, and 4 Plates. 2 vols. square crown 
 8vo. 31s. 6d. cloth. 
 
 * # * The Original Edition, with more 
 numerous Illustrations, in 2 vols. 4to. price 
 48s. may also be had. 
 
 Dr. Copland's Dictionary of Practical 
 
 Medicine : Comprising Greneral Pathology, 
 the Nature and Treatment of Diseases, 
 Morbid Structures, and the Disorders es- 
 pecially incidental to Climates, to Sex, and 
 to the different Epochs of Life ; with nume- 
 rous approved Formulse of the Medicines 
 recommended. Now complete in 3 vols. 
 8vo. price 5. 11s. cloth. 
 
 Bishop Cotton's Instructions in the 
 
 Doctrine and Practice of Christianity. In- 
 tended chiefly as an Introduction to Confir- 
 mation. Fourth Edition. 18mo. 2s. 6d. 
 
 Cresy's Encyclopaedia of Civil Engi- 
 neering, Historical, Theoretical, and Prac- 
 tical. Illustrated by upwards of 3,000 
 Woodcuts. Second Edition^ revised and 
 brought down to the Present Time in a 
 Supplement,comprising Metropolitan Water- 
 Supply, Drainage of Towns, Railways, 
 Cubical Proportion, Brick and Iron Con- 
 struction, Iron Screw Piles, Tubular Bridges,' 
 &c, 8vo. 63s. cloth. 
 
 Crosse. Memorials, Scientific and Li- 
 terary, of Andrew Crosse, the Electrician. 
 Edited by Mrs. CBOSSE. Post Svo. 9s. 6d. 
 
 Crowe. The History of France. By 
 
 EYKE EYANS CEO WE. In Five Volumes. 
 YOL. I. 8vo. price 14s. 
 
PUBLISHED BY LONGMAN, GREEN, AND CO. 
 
 Cruikshank. The Life of Sir John 
 
 Falstaff, illustrated iu a Series ol'Twoiflv- 
 four original Etchings by George Cruik- 
 shuuk. Accompanied by an imaginary 
 Biography of the Knight by ROBEET 13. 
 BBOUGH. Royal 8vo. price 12s. (id. cloth. 
 
 Lady Gust's Invalid's Book. The In- 
 valid's Own Book : A Collection of Recipes 
 froiii various Books and various Countries. 
 By the Honourable LADY CUST. Second 
 Edition. Fcp. Svo. price 2s. 6d. 
 
 Dale. T he Domestic Liturgy and Family 
 
 Chaplain, in Two Parts : PAET I. Church 
 Services adapted for Domestic Use, with 
 Prayers for Every Day of the Week, selected 
 from, the Book of Common Prayer; PABT 
 II. an appropriate Sermon foi* Every Sunday 
 in the Year. By the Rev. THOMAS DALE, 
 M.A., Canon Residentiary of St. Paul's. 
 Second Edition. Post 4to. 21s. cloth j 
 31s. 6d. calf j or 2. 10s. morocco. 
 
 r THE FAMILY CHAPLAUT, 12s. 
 
 Separately \ THB DoM8HO LlTUEQy 10a> ^ 
 
 Davy (Dr. J.) The Angler and his 
 
 Friend ; or, Piscatory CoUoquies and Fish- 
 ing Excursions. By JOHN DAYY, M.D., 
 F.R.S., &o. Fcp. Svo. price 6s. 
 
 The Angler in the Lake District : or, Piscatory 
 Colloquies and Fishing Excursions in West- 
 moreland and Cumberland. By JOHN 
 DAYY, M.D., F.R.S. Fcp. Svo. 6s. 6d. 
 
 De Fonblanque, The Administration 
 
 and Organisation of the British Army, with 
 especial reference to Finance and Supply. 
 By EDWARD BAEBINGTON DE FONBLANQUE, 
 Assistant Commissary- General. Svo. 12s. 
 
 De la Rive. A Treatise on Electricity 
 
 in Theory and Practice. By A. DE LA RIVE, 
 Professor in the Academy of Geneva. Trans- 
 lated for the Author by C. V. WALKEE, 
 F.R.S. With numerous Woodcut Illustra- 
 tions. 3 vole. Svo. price 3. 13s. cloth. 
 
 Domenech. Seven Years' Residence in 
 
 the Great Deserts of North America. By 
 the ABBE DOMENECH. With a Map, and 
 about Sixty Woodcut Illustrations. 2 vols. 
 Svo. [Just ready. 
 
 The Abbe Domenech's Missionary Adventures 
 in Texas and Mexico : A Personal Narrative 
 of Six Years' Sojourn in those Regions. 
 Translated under the Author's superin- 
 tendence. Svo. with Map, 10s. 6d. 
 
 The Eclipse of Faith; or, a Visit to a 
 
 Religious Sceptic. VthLdition. Fcp. Svo. 5s. 
 
 Defence of The Eclipse of Faith, by its 
 Author: Being a Rejoinder to Professor 
 Newman's Reply : Including a full Exami- 
 nation of that Writer's Criticism on the 
 Character of Christ ; and a Chapter on the 
 Aspects and Pretensions of Modern Deism. 
 Second Edition, revised. Post Svo. 5s. 6d. 
 
 The Englishman's Greek Concordance of 
 
 the New Testament : Being an Attempt at a 
 Verbal Connexion between the Greek and 
 the English Texts ; including a Concordance 
 to the Proper Names, with Indexes, Greek- 
 English and English-Greek. New Edition, 
 with a new Index. Royal Svo. price 42s. 
 
 The Englishman's Hebrew and Chaldee Con- 
 cordance of the Old Testament : Being an 
 Attempt at a Verfcal Connexion between 
 the Original and the English Translations ; 
 with Indexes, a List of the Proper Names 
 and their Occurrences, &c. 2 vols. royal 
 Svo. 3. 13s. 6d. j large paper, 4. 14s. 6d. 
 
 Ephemera's Handbook of Angling; 
 
 teaching Fly-Fishing, Trolling, Bottom- 
 Fishing, Salmon-Fishing : W r ith the Natural 
 History of River-Fish, and the best Modes 
 of Catching them. Third Edition, corrected 
 and improved} with Woodcuts. Fcp. Svo. 5s. 
 
 Ephemera's Book of the Salmon: Com- 
 prising the Theory, Principles, and Prac- 
 tice of Fly-Fishing for Salmon; Lists of 
 good Salmon Flies for every good River in 
 the Empire ; the Natural History of the 
 Salmon, its Habits described, and the best 
 way of artificially Breeding it. Fcp. Svo. 
 with coloured Plates, price 14s. 
 
 Fairbairn. Useful Information for En- 
 gineers : Being a Series of Lectures delivered 
 to the Working Engineers of Yorkshire and 
 Lancashire. With Appendices, containing 
 the Results of Experimental Inquiries into 
 the Strength of Materials, the Causes of 
 Boiler Explosions, &c. By WILLIAM 
 FAIBBAIEN, F.R.S., F.G.S. Second Edition ; 
 with numerous Plates and Woodcuts. Crown 
 Svo. price 10s. 6d. 
 
 First Impressions of the New World on 
 
 Two Travellers from the Old in the Autumn 
 of 1858 : with Map by Arrowsmith. Post 
 Svo. 8s. Gd. 
 
 Fischer. Francis Bacon of Verulam: 
 
 Realistic Philosophy and its Age. By Dr. 
 K. FISCHEB. Translated by JOHN OXBN- 
 POED. Post Svo. 9s. 6d. 
 
 B 4 
 
NEW WORKS AND NEW EDITIONS 
 
 Forester. Rambles in the Islands of 
 
 Corsica and Sardinia : With Notices of 
 their History, Antiquities, and present 
 Condition. By THOMAS FORESTER, Au- 
 thor of Norway in 1848-1849. With 
 coloured Map ; and numerous Illustrations 
 in Colours and Tints and on Wood, from 
 Drawings made during the Tour by Lieut. - 
 Col. M. A. BIDDTTLPH, E.A. Imperial 
 Svo. price 28s. 
 
 Frazer. Letters of Sir A. S. Frazer, 
 
 K.C.B., Commanding the Eoyal Horse Artil- 
 lery under the Duke of Wellington : Written 
 during the Peninsular and Waterloo Cam- 
 paigns. Edited by Major- General SABINE, 
 E.A. With Portrait, 2 Maps, and Plan. 
 8vo. 18?. 
 
 Freeman and Salvin, Falconry : Its 
 
 Claims, History, and Practice. By GAGE 
 EARLE FREEMAN, M,A. (" Peregrine" of the 
 Field newspaper) ; artd Capt. F. H. SALYIN. 
 Post Svo. with Woodcut Illustrations from 
 Drawings by Wolf. 
 
 Oarratt. Marvels and Mysteries of In- 
 stinct ; or, Curiosities of Animal Life. By 
 G-EORaE GARRATT. Second Edition, revised 
 and improved ; with a Frontispiece. Fcp. 
 SYO. price 4s. 6d. 
 
 Gilbart.A Practical Treatise on Bank- 
 ing. By JAMES WILLIAM GILBART, F.E.S. 
 Sixth Edition, revised and enlarged. 2 rols. 
 12mo. Portrait, 16s. 
 
 Gilbart's Logic of Banking : a Familiar Ex- 
 position of the Principles of Eeasoning, and 
 their application to the Art and the Science 
 of Banking. 12mo. with Portrait, 12s. 6d. 
 
 Gleig, Essays, Biographical, Historical, 
 
 and Miscellaneous, contributed chiefly to the 
 Edinburgh and Quarterly Reviews. By the 
 Eev, G. E, GLEIG, M.A., Chaplain-General 
 to the Forces and Prebendary of St. Paul's. 
 2 vols. 8vo. 21s. 
 
 1. Dr. Chalmere. 
 
 2. Our Defensive Arma- 
 
 ment. 
 
 3. Natural Theology. 
 
 4. Military Bridges. 
 
 5. TheWarofthePunjaub. 
 
 CONTENTS. 
 
 6. The Puritans. 
 
 7. General Miller. 
 
 8. India and its Army. 
 
 9. The Madchenstien. 
 10. Military Education. 
 
 The Poetical Works of Oliver Goldsmith. 
 
 Edited by BOLTON CoRNEY, Esq. Illustrated 
 by Wood Engravings, from Designs by 
 Members of the Etching Club. Square 
 crown 8vo. cloth, 21s. ; morocco, 1. 16s. 
 
 Gosse. A Naturalist's Sojourn in 
 
 Jamaica. By P. H. GOSSE, Esq. With 
 Plates. Post 8vo. price 14s. 
 
 Greathed. Letters written during the 
 
 Siege of Delhi. By H. H. GREATHED, late 
 of the Bengal Civil Service. Edited bj his 
 Widow. Post 8vo. 8s. 6d. 
 
 Green. Lives of the Princesses of Eng- 
 land. By Mrs. MAET ANNE ETEEETT 
 GREEN, Editor of the Letters of Royal and 
 Illustrious Ladies. With numerous Por- 
 traits. Complete in 6 vols. post Svo. price 
 10s. 6d. each. Any Yolume may be had 
 separately to complete sets. 
 
 Greyson. Selections from the Corre- 
 spondence of E. E. H. GREYSON, Esq. 
 Edited by the Author of The Eclipse of 
 Faith. Second Edition. Crown Svo. 7s. 6d. 
 
 Grove, The Correlation of Physical 
 
 Forces. By W. E. GROYE, Q.C., M.A., 
 F.E.S., &c. Third Edition. Svo. price 7s. 
 
 Gurney. St. Louis and Henri IV. : Being 
 
 a Second Series of Historical Sketches. 
 By the Eev. JOHN H. GTTBNEY, M. A., Rector 
 of St. Mary's, Marylebone. Fcp. Svo. 6s. 
 
 Evening Recreations ; or, Samples from the 
 Lecture-Eoom. Edited by the Eev. J. H. 
 GURNEY, M.A. Crown Svo. 5s. 
 
 GwiltY Encyclopaedia of Architecture, 
 
 Historical, Theoretical, and Practical. By 
 JOSEPH GWILT. With more than 1,000 
 Wood Engravings, from Designs by J. S. 
 GWILT. Fourth Edition. Svo. 42s. 
 
 Hare (Archdeacon). The Life of Luther, 
 
 in Forty-eight Historical Engravings. By 
 GTISTAY KONIG-. With Explanations by 
 Archdeacon HABE and SUSANNA WINK- 
 WOETH. Fcp. 4to. price 28s. 
 
 Harford. Life of Michael Angelo Buon- 
 arroti: With Translations of many of his 
 Poems and Letters ; also Memoirs of Savo- 
 narola, Eaphael, and Yittoria Colonna. By 
 JOHN S. HARFORD, Esq., D.C.L., F.E.S. 
 Second Edition, thoroughly revised ; with 
 20 copperplate Engravings. 2 vols. Svo. 25s. 
 
 Illustrations, Architectural and Pictorial, of 
 the Genius of Michael Angelo Buonarroti. 
 With Descriptions of the Plates, by the 
 Commendatore CANINA ; C. E. COCKEEELL, 
 Esq., E.A. ; and J. S. HARFORD, Esq., 
 D.C.L., F.E.S. Folio, 73s. 6d. half-bound. 
 
 Harrison. The Light of the Forge ; or, 
 
 Counsels drawn from the Sick-Bed of E. M. 
 By the Eev. W. HAEEISON, M.A., Domestic 
 Chaplain to H.E.H. the Duchess of Cam- 
 bridge. Fcp. Svo. price 5s. 
 
PUBLISHED BY LONGMAN, GREEN, AND CO. 
 
 Harry Hieover. Stable Talk and Table 
 
 Talk ; or, Spectacles for Young Sportsmen. 
 By HARRY HOOVER. New Edition, 2 vols. 
 8vo. with Portrait, price 24s. 
 
 Harry Hieover.- The Hunting-Field. By Harry 
 HIEOVER. With Two Plates. Fcp. 8ro. 
 5s. half-bound. 
 
 Harry Hieover. Practical Horsemanship. 
 By HARRY HIEOVER. Second Edition ; with 
 2 Plates. Fcp. 8vo. 5s. half-bound. 
 
 Harry Hieover. The Pocket and the Stud; or, 
 Practical Hints on the Management of the 
 Stable. By HARRY HIEOVEB. Third 
 Edition ; with Portrait of the Author. Fcp. 
 8vo. price 5s. half-bound. 
 
 Harry Hieover. The Stud, for Practical Pur- 
 poses and Practical Men: Being a Guide 
 to the Choice of a Horse for use more than 
 for show. By HARRY HIEOVER. With 
 2 Plates. Fcp. 8vo. price 5s. half-bound. 
 
 Hassall. Adulterations Detected; or, 
 
 Plain Instructions for the Discovery of 
 Frauds in Food and Medicine. By ARTHUR 
 HILL HASSALL, M.D. Lond., Analyst of The 
 Lancet Sanitary Commission ; and Author of 
 the Reports of that Commission published 
 under the title of Food and its Adulterations 
 (which may also be had, in 8vo. price 28s.) 
 With 225 Illustrations, engraved on Wood. 
 Crown 8vo. 17s. 6d. 
 
 Hassall. A History of the British Fresh 
 
 Water Algae : Including Descriptions of the 
 Desmidese and Diatomacese. With upwards 
 of One Hundred Plates of Figures, illus- 
 trating the various Species. By ARTHTTK 
 HILL HASSALL, M.D., Author of Micro- 
 scopic Anatomy of the Human Body, &c. 2 
 vols. 8vo. with 103 Plates, price 1. 15s. 
 
 Col. Hawker's Instructions to Young 
 
 Sportsmen in all that relates to Guns and 
 Shooting. llth Edition, revised by the 
 Author's Son, Major P. W. L. HAWKER ; 
 with a Bust of the Author, and numerous 
 Illustrations. Square crown 8vo. 18s. 
 
 Haydn's Book of Dignities : Containing 
 
 Kolls of the Official Personages of the British 
 Empire, Civil, Ecclesiastical, Judicial, Mili- 
 tary, Naval, and Municipal, from the Earliest 
 Periods to the Present Time. Together 
 with the Sovereigns of Europe, from the 
 Foundation of their respective States ; the 
 Peerage and Nobility of Great Britain ; &c. 
 Being a New Edition, improved and conti- 
 nued, of Beatson's Political Index. 8vo. 
 price 25s. half-bound. 
 
 Hayward. Biographical and Critical 
 
 Essays, reprinted from Kevicws, with Ad- 
 ditions and Corrections. By A. HAYWARD, 
 Esq., Q.C. 2 vols. 8vo. price 24s. 
 
 1. Sydney Smith. 
 
 2. Samuel Holers. 
 8. James Smith. 
 
 4. George Sehwu. 
 
 5. Lord Chesterfield. 
 
 6. Lord Melbourne. 
 
 7. General Von Radowitz. 
 
 8. Countess Hahn-Hahn. 
 I). De Stendahl (Henri 
 
 10. Pierre Dupo: 
 
 11. Lord Eldon and the 
 
 int. 
 
 Chances of the Bar. 
 
 12. The Crimean Campaign. 
 ];. American Orators and 
 Statesmen. 
 
 14. Journalism in France. 
 
 15. Parisian Morals and 
 
 Manners. 
 
 Ifl. The Imitative Powers of 
 Music. 
 
 17. British Field Sports. 
 
 18. Science and Literature 
 
 of Etiquette. 
 
 19. The Art of Dining. 
 
 Sir John Herschel. Outlines of Astro- 
 nomy. By SIB JOHN F. W. HEBSCHEL, 
 Bart., K.H., M.A. Fifth Edition, revised 
 and corrected to the existing state of Astro- 
 nomical Knowledge ; with Plates and Wood- 
 outs. 8vo. price 18s. 
 
 Sir John Herschel's Essays from the Edin- 
 burgh and Quarterly Reviews, with Ad- 
 dresses and other Pieces. 8vo. price 18s. 
 
 Hinchliff. Summer Months among the 
 
 Alps : With the Ascent of Monte Rosa. 
 By THOMAS W. HINCHLIFF, of Lincoln's 
 Inn, Barrister-at-Law. With 4 tinted 
 Views and 3 Maps. Post 8vo. price 10s. 6d. 
 
 Hints on Etiquette and the Usages of 
 
 Society: With a Glance at Bad Habits. 
 New Edition, revised (with Additions) by a 
 Lady of Rank. Fcp.Svo. price Half-a-Crown. 
 
 Holland. Medical Notes and Reflec- 
 tions. By SIE HENBT HOLLAND, Bart., 
 M.D., F.R.S., &c., Physician in Ordinary 
 to the Queen and Prince-Consort. Third 
 Edition, revised throughout and corrected j 
 with some Additions. 8vo. 18s. 
 
 Sir H. Holland's Chapters on Mental Physi- 
 ology, founded chiefly on Chapters contained 
 in Medical Notes and Reflections. Second 
 Edition. Post 8vo. price 8s. 6d. 
 
 Hooker. Kew Gardens; or, a Popular 
 
 Guide to the Royal Botanic Gardens of 
 Kew. By SIE WILLIAM JACKSON HOOKEE, 
 K.H., &c., Director. IGmo. price Sixpence. 
 
 Hooker and Arnott. The British Flora ; 
 
 comprising the Pheenogamous or Flowering 
 Plants, and the Ferns. Seventh Edition, 
 with Additions and Corrections ; and nu- 
 merous Figures illustrative of the Umbelli- 
 ferous Plants, the Composite Plants, the 
 Grasses, and the Ferns. By SIE W. J. 
 HOOKEB, F.R.A. and L.S., &c. ; and G. A. 
 WALXEB-ABNOTT, LL.D., F.L.S. 12mo. 
 with 12 Plates, price 14s. j with the Plates 
 coloured, price 21s. 
 
 B 5 
 
10 
 
 NEW WORKS AND NEW EDITIONS 
 
 Home's Introduction to the Critical 
 
 Study and Knowledge of the Holy Scrip- 
 tures'. Tenth Edition, revised, corrected, 
 and brought down to the present time. 
 Edited by the Rev. T. HAETWELL HOENE, 
 B.D. (the Author) ; the Eev. SAMUEL 
 DAVIDSON, D.D. of the University of Halle, 
 and LL.D. ; and S. PEIDEATTX TEEGELLES, 
 LL.D. With 4 Maps and 22 Yignettes and 
 Facsimiles. 4 vols. 8vo. 3. 13s. 6d. 
 
 ** The Four Volumes may also be had separately as 
 follows : 
 
 Vol. I. A Summary of the Evidence for the Genuineness, 
 Authenticity, Uncorrupted Preservation, and Inspiration of 
 the Holy Scriptures. By the Eev. T. H. Home, B.D. . 8vo. 15s. 
 
 Vol. II. The Text of the Old Testament considered : With 
 a Treatise on Sacred Interpretation ; and a brief Introduc- 
 tion to the Old Testament Books and the Apocrypha. By S. 
 Davidson, D.D. (Halle) and LL.D 8vo. 25s. 
 
 VOL. III. A Summary of Biblical Geography and Anti- 
 quities. By the Rev. T. H. Home, B.D 8vo. 18s. 
 
 Vol. TV. An Introduction to the Textual Criticism of the 
 New Testament. By the Eev. T. H. Home, B.D. The 
 Critical Part re-written, and the remainder revised and 
 edited by S. P. Tregelles, LL.D 8vo. 18s. 
 
 Home. A Compendious Introduction 
 
 to the Study of the Bible. By the Eev. 
 T. HAETWELL HOENE, B.D. New Edition, 
 with Maps and Illustrations. 12mo. 9s 
 
 Hoskyns. Talpa ; or, the Chronicles of 
 
 a Clay Earm : An Agricultural Eragment. 
 By CHANDOS WEEN HOSKYNS, Esq. Eourth 
 Edition. With 24 Woodcuts from the 
 original Designs by G-EOEGE CEUIZSHANK. 
 16mo. price 5s. 6d. 
 
 Howitt (A. M.) An Art-Student in 
 Munich. By ANNA MAET HOWITT. 2 
 vols. post 8vo. price 14s. 
 
 Howitt The Children's Year. By Mary 
 
 HOWITT. With Eour Illustrations, from 
 Designs by A. M. HOWITT. Square 16mo. 5s. 
 
 Howitt. Tallangetta, the Squatter's 
 
 Home : A Story of Australian Life. By 
 WILLIAM HOWITT, Author of Two Tears in 
 Victoria, &c. 2 vols. post 8vo. price 18s. 
 
 Howitt. Land, Labour, and Gold; 
 
 or, Two Years in Victoria : With Visit to 
 Sydney and Van Diemen's Land. By 
 WILLIAM HOWITT. Second Edition, con- 
 taining the most recent Information re- 
 garding the Colony. 2 vols. crown 8vo. 
 price 10s. 
 
 Howitt. Visits to Remarkable Places : 
 
 Old Halls, Battle-Eields, and Scenes illustra- 
 tive of Striking Passages in English History 
 and Poetry. By WILLIAM HOWITT. With 
 about 80 Wood Engravings. New Edition. 
 2 vols. square crown 8vo. price 25s. 
 
 William Howitt's Boy's Country Book; 
 
 Being the Real Life of a Country Boy, 
 written by himself ; exhibiting all the 
 Amusements, Pleasures, and Pursuits oi 
 Children in the Country. New Edition ; 
 with 40 Woodcuts. Ecp. 8vo. price 6s. 
 
 Howitt. The Rural Life of England. By 
 WILLIAM HOWITT. New Edition, cor- 
 rected and revised ; with Woodcuts by 
 Bewick and Williams. Medium 8vo. 21s. 
 
 The Abbe' Hue's work on the Chinese 
 
 Empire, founded on Eourteen Years' Travels 
 and Residence in China. People's Edition. 
 with 2 Woodcut Illustrations. Crown 8vo 
 price 5s. 
 
 Hue. Christianity in China, Tartary 
 
 and Thibet. By M. 1' Abbe Hue, formerly 
 Missionary Apostolic in China ; Author o: 
 The Chinese Empire, &c. VOLS. I. and II 
 8vo. 21s. ; and VOL. III. price 10s. 6d. 
 
 Hudson's Plain Directions for Making 
 
 Wills in conformity with the Law. Nev, 
 Edition, corrected and revised by the 
 Author ; and practically illustrated by Spe- 
 cimens of Wills containing many varieties 
 of Bequests, also Notes of Cases judicially 
 decided since the Wills Act came into ope- 
 ration. Ecp. 8vo. 2s. 6d. 
 
 Hudson's Executor's Guide. New and 
 
 enlarged Edition, revised by the Autho/ 
 with reference to the latest reported Case: 
 and Acts of Parliament. Fcp. 8vo. 6s. 
 
 Hudson and Kennedy. Where there '?> 
 
 a Will there 's a Way : An Ascent of Mont. 
 Blanc by a New Route and Without Guides. 
 By the Rev. C. HUDSON, M.A., and E. g. 
 KENNEDY, B.A. Second Edition, with Plat.? 
 and Map. Post 8vo. 5s. 6d. 
 
 Humboldt's Cosmos. Translated, with 
 
 the Author's authority, by MES. SABIKE. 
 VOLS. I. and II. 16nio. Half-a-Crown each, 
 sewed ; 3s. 6d. each, cloth : or in post 8vo. 
 12s. each, cloth. VOL. III. post 8vo. 
 12s. 6d. cloth : or in 16mo. PAET I. 2s. 6d. 
 sewed, 3s. 6d. cloth ; and PAET II. 3s. sewed, 
 4s. cloth. VOL, IV. PAET I. post 8vo. 15?. 
 cloth; and 16mo. price 7s. 6d. cloth, or 
 7s. sewed. 
 
 Humboldt's Aspects of Nature. Translated, 
 with the Author's authority, by MES.SABINT;. 
 16mo. price 6s. : or in 2 vols. 3s. 6d. each, 
 cloth j 2s. 6.d. each, sewed. 
 
PUBLISHED BY LONGMAN, GREEK, AND CO. 
 
 
 Humphreys. Parables of Our Lord, 
 
 illuminated and ornamented in the style of 
 the Missals of the Renaissance by HENRY 
 NOEL HUMPHREYS. Square fcp. 8vo. 21s. 
 
 in m;;.- -i . - rawed covers ; or 30s. bound in 
 morocco by Hay day. 
 
 Hunt. Researches on Light in its 
 
 Chemical Relations ; embracing a Con- 
 sideration of all the Photographic Processes. 
 By ROBEBT HUNT, F.R.S. Second Edition, 
 with Plate and Woodcuts. 8vo. 10s. 6d. 
 
 Hunt (Captain). The Horse and his 
 
 Master : With Hints on Breeding, Breaking, 
 Stable-Management, Training, Elementary 
 Horsemanship, Riding to Hounds, &c. By 
 VERB D. HUNT, Esq., late 109th Regt. Co, 
 Dublin Militia. Fcp. 8vo. with Frontispiece, 
 price 5s. 
 
 Hutchinson. Impressions of Western 
 
 Africa : With a Report on the Peculiarities 
 of Trade up the Rivers in the Bight of 
 Biafra. By T. J. HTJTCHINSON, Esq., 
 British Consul for the Bight of Biafra and 
 the Island of Fernando Po. Post 8vo. 
 price 8s. 6d. 
 
 Idle. Hints on Shooting, Fishing, &c., 
 
 both on Sea and Land, and in the Fresh- 
 Water Lochs of Scotland : Being the Expe- 
 riences of C. IDLE, Esq. Fcp. 8vo. 5s. 
 
 Mrs. Jameson's Legends of the Saints 
 
 and Martyrs, as represented in Christian Art : 
 Forming the FIRST SERIES of Scared and 
 Legendary Art. Third Edition, revised and 
 improved; with 17 Etchings and upwards 
 of 180 Woodcuts, many of which are new 
 in this Edition. 2 vols. square crown 8vo. 
 price 31s. 6d. 
 
 Mrs. Jameson's Legends of the Monastic 
 Orders, as represented in Christian Art. 
 Forming the SECOND SERIES of Sacred and 
 Legendary Art, Second Edition, enlarged ; 
 with 11 Etchings by the Author, and 88 
 Woodcuts. Square crown 8vo. price 28s. 
 
 Mrs. Jameson's Legends of the Madonna, 
 as represented in Christian Art : Forming 
 the THIRD SERIES of Sacred and Legendary 
 Art. Second Edition, corrected and en- 
 larged ; with 27 Etchings and 165 Wood 
 Engravings. Square crown 8vo. price 28s. 
 
 Mrs. Jameson's Commonplace-Book of 
 
 Thoughts, Memories, and Fancies, Original 
 and Selected. PART I. Ethics and Character ; 
 PART II. Literature and Art. Second Edit. 
 revised and corrected ; with Etchings and 
 Woodcuts. Crown 8vo. 18s. 
 
 Mrs. Jameson's Two Lectures on the 
 
 Social Employments of Women, Sisters of 
 Charity and the Communion of Labour. New 
 Edition, with a Prefatory Letter on the 
 present Condition and Requirements of the 
 Women of England. Fcp. 8vo. 2s. 
 
 Jaquemet's Compendium of Chronology: 
 
 Containing the most important Dates of 
 General History, Political, Ecclesiastical, 
 and Literary, from the Creation of the 
 World to the end of the Year 1854. : Second 
 Edition. Post 8vo. price 7s. 6d. 
 
 Jaquemet's Chronology for Schools : Contain- 
 ing the most important Dates of General 
 History, Political, Ecclesisastical, and 
 Literary, from the Creation of the World 
 to the end of the year 1857. Edited by the 
 Rev. J. ALCORN, M.A. Fcp. 8vo. 3s. 6d. 
 
 Lord Jeffrey's Contributions to The 
 
 Edinburgh Review. A New Edition, com- 
 plete in One Volume, with a Portrait en- 
 graved by Henry Robinson, and a Vignette. 
 Square crown 8vo. 21s. cloth ; or 30s. calf. 
 Or in 3 vols. 8vo. price 42s. Comprising 
 
 1. General Literature arid Literary Bio- 
 
 graphy. 
 
 2. History and Historical Memoirs. 
 
 3. Poetry. 
 
 4. Philosophy of the Mind, Metaphysics, 
 
 and Jurisprudence. 
 
 5. Novels, Tales, and Prose Works of Fiction. 
 
 6. General Politics. 
 
 7. Miscellaneous Literature, &c. 
 
 Bishop Jeremy Taylor's Entire Works : 
 
 With Life by BISHOP HEBEB. Revised and 
 corrected by the Rev. CHARLES PAGE EDEN, 
 Fellow of Oriel College, Oxford. Now 
 complete in 10 vols. 8vo. 10s. 6d. each. 
 
 Keith Johnston's, New Dictionary of 
 
 Geography, Descriptive, Physical, Statistical, 
 and Historical: Forming a complete Gene- 
 ral Gazetteer of the World. N<<w Edition, 
 rectified to May 1859. In One Volume of 
 1,360 pages, comprising about 50,000 Names 
 of Places. 8vo. 30s. cloth; or 35s. half- 
 bound in russia. 
 
 Kane. Wanderings of an Artist among 
 
 the Indians of North America ; from Canada 
 to Vancouver's Island and Oregon, through 
 the Hudson's Bay Company's Territory, and 
 back again. By PAUL KANE. With Map, 
 Illustrations in Colours, and Wood En- 
 gravings. 8vo. 21s. 
 
 Kemble. The Saxons in England: A 
 
 History of the English Commonwealth till 
 the Norman Conquest. By JOHX M. 
 BLE, M.A., Ac. 2 vols. 8vo. 28s. 
 
 B 6 
 
NEW WOEKS AND NEW EDITIONS 
 
 Kesteven. A Manual of the Domestic 
 
 Practice of Medicine. By W. B . KESTEVEN, 
 Fellow of the Royal College of Surgeons of 
 England, &c. Square post 8vo. 7s. 6d. 
 
 Kirby and Spence's Introduction to 
 
 Entomology; or, Elements of the Natural 
 History of Insects : Comprising an Account 
 of Noxious and Useful Insects, of their Meta- 
 morphoses, Food, Stratagems, Habitations, 
 Societies, Motions, Noises, Hybernation, 
 Instinct, &c. Seventh Edition, with an Ap- 
 pendix relative to the Origin and Progress 
 of the work. Crown 8vo, 5s. 
 
 A Lady's Tour round Monte Rosa; 
 
 With Visits to the Italian Valleys of An- 
 zasca, Mastalone, Camasco, Sesia, Lys, 
 Challant, Aosta, and Cogne : In a Series of 
 Excursions in the Years 1850, 1856, 1858. 
 With Map, 4 Illustrations in Colours from 
 Sketches by Mr. Gr. Barnard, and 8 Wood 
 Engravings. Post 8vo. 14s. 
 
 Mrs. R. Lee's Elements of Natural His- 
 tory ; or, First Principles of Zoology : Com- 
 prising the Principles of Classification, inter- 
 spersed with amusing and instructive Ac- 
 counts of the most remarkable Animals. 
 New Edition; Woodcuts. Fcp.8vo.7s.6d. 
 
 LARDIMER'S CABINET CYCLOPAEDIA 
 
 Of History, Biography, Literature, the Arts and Sciences, Natural History, and Manufactures. 
 
 A Series of Original Works by 
 
 SIR JOHN HERSCHEL, 
 SIR JAMES MACKINTOSH, 
 ROBERT SOUTHEY, 
 SIR DAVID BREWSTER, 
 
 THOMAS KEIOHTLEY, 
 JOHN FORSTER, 
 SIR WALTER SCOTT, 
 THOMAS MOORE, 
 
 BISHOP THIRLWALL, 
 THE REV. G. R. GLEIG, 
 J. C. L. DE SISMONDI, 
 JOHN PHILLIPS, F.R.S., G.S. 
 
 AND OTHER EMINENT WRITERS. 
 
 Complete in 132 vols. fcp. 8ro. with Vignette Titles, price, in cloth, Nineteen Guineas. 
 The Works separately, in Sets or Series, price Three Shillings and Sixpence each Volume. 
 
 A List of the WORKS composing the CABINET CYCLOPAEDIA : 
 
 1. Bell's History of Russia 3 vols. 10s. 6d. 
 
 2. Bell's Lives of British Poets 2 vols. 7s. 
 
 8. Brewster's Optics 1 vol. 3s. 6d. 
 
 4. Cooley's Maritime and Inland Discovery 3 vols. 10s. 6d. 
 
 5. Crowe's History of France 3 vols. 10s. 6d. 
 
 6. De Morgan on Probabilities 1 vol. 3s. 6d. 
 
 7. De Sismondi's History of the Italian 
 
 Republics 1 vol. 3s. Gd. 
 
 8. De Sismondi's Fall of the Roman Empire 2 vols. 7s. 
 
 9. Donovan's Chemistry 1 vol. 3s. fid. 
 
 10. Donovan's Domestic Economy 2 vols. 7s. 
 
 11. Dunham's Spain and Portugal 5 vols. 17s. 6d. 
 
 12. Dunham's History of Denmark, Sweden, 
 
 and Norway 3 vols. 10s. 6d. 
 
 13. Dunham's History of Poland 1 vol. 3s. 6d. 
 
 14. Dunham's Germanic Empke 3 vols. 10s. 6d. 
 
 15. Dunham's Europe during the Middle 
 
 Ages 4 vols. 14s. 
 
 16. Dunham's British Dramatists 2 vols. 7s. 
 
 17. Dunham's Lives of Early Writers of 
 
 Great Britain 1 vol. 3s. 6d. 
 
 18. Fergus's History of the United States . . 2 vols. 7s. 
 
 19. Fosbroke's Grecian & Roman Antiquities 2 vols. 7s. 
 
 20. Forster's Lives of the Statesmen of the 
 
 Commonwealth 5 vols. 17s. 6d. 
 
 21. Gleig's Lives of British Military Com- 
 
 manders 3 vols. 10s. 6d. 
 
 22. Grattan's History of the Netherlands ... 1 vol. 3s. 6d. 
 
 23. Henslow's Botany 1 vol. 3s. Gd. 
 
 24. Herschel's Astronomy 1 vol. 3s. 6d. 
 
 25. Herschel's Discourse on Natural Philo- 
 
 sophy 1 vol. 3s. Gd. 
 
 26. History of Rome 2 vols. 7s. 
 
 27. History of Switzerland 1 vol. 3s. Gd. 
 
 28. Holland's Manufactures in Metal 8 vols. 10s. Gd. 
 
 29. James's Lives of Foreign Statesmen .... 5 vols. 17s. Gd. 
 
 30. Kater and Lardner's Mechanics 1 vol. 3s. Gd. 
 
 81. Keightley's Outlines of History 1 vol. 3s. Gd. 
 
 32. Lardner's Arithmetic 1 vol. 8s. 6d. 
 
 83. Lardner's Geometry 1 vol. 3s. 6d. 
 
 34. Lardner on Heat 1 vol. 3s. Od. 
 
 35. Lardner's Hydrostatics and Pneumatics 1 vol. 3s. Gd. 
 
 36. Lardner and Walker's Electricity and 
 
 Magnetism 2 vols. 7s. 
 
 37. Mackintosh, Forster, and Courtenay's 
 
 Lives of British Statesmen 7 vols. 21s. Gd. 
 
 38. Mackintosh, Wallace, and Bell's History * 
 
 of England 10 vols. 35s. 
 
 89. Montgomery and Shelley's eminent Ita- 
 lian, Spanish, and Portuguese Authors 3 vols. 10s. Gd. 
 
 40. Moore's History of Ireland 4 vols. 14s. 
 
 41. Nicolas's Chronology of History 1 vol. 3s. 6d. 
 
 42. Phillips's Treatise on Geology 2 vols. 7s. 
 
 43. Powell's History of Natural Philosophy 1 vol. 3s. Gd. 
 
 44. Porter's Treatise on the Manufacture of 
 
 Silk 1 vol. 3s. 6d. 
 
 45. Porter's Manufactures of Porcelain and 
 
 Glass 1 vol. 3s. 6d. 
 
 46. Roscoe's British Lawyers 1 vol. 3s. Gd. 
 
 47. Scott's History of Scotland 2 vols. 7s. 
 
 48. Shelley's Lives of eminent French 
 
 Authors .2 vols. 7s. 
 
 49. Shuckard and Swainson's Insects 1 vol. 3s. 6d. 
 
 50. Southey's Lives of British Admirals .... 5 vols. 17s. 6d. 
 
 51. Stebbing's Church History 2 vols. 7s. 
 
 52. Stebbing's History of the Reformation. . 2 vols. 7s. 
 
 53. Swainson's Discourse on Natural History 1 vol. 3s. 6d. 
 
 54. Swainson's Natural History and Classi- 
 
 fication of Animals 1 vol. 3s. Gd. 
 
 55. Swainson's Habits and Instincts of 
 
 Animals 1 vol. 3s. Gd. 
 
 56. Swainson's Birds 2 vols. 7s. 
 
 57. Swainson's Fish, Reptiles, &c 2 vols. 7s. 
 
 58. Swainson's Quadrupeds 1 vol. 3s. Gd. 
 
 59. Swainson's Shells and Shell-Fish 1 vol. 3s. Gd. 
 
 60. Swainson's Animals in Menagerie* 1 vol. 3s. 6d. 
 
 61. Swainson's Taxidermy and Biography of 
 
 Zoologists 1 vol. 3s. Gd. 
 
 G2. Thirlwall's History of Greece 8 vols. 28s. 
 
PUBLISHED BY LONGMAN, GREEN, AND CO. 
 
 The Letters of a Betrothed. Fcp. 8vo. 
 
 price 5s. cloth. 
 
 Letters to my Unknown Friends. By 
 
 a LADY, Author of Letters on Happiness. 
 Fourth Edition. Fcp. 8vo. 5s. 
 
 L.E.L. The Poetical Works of Letitia 
 
 Elizabeth Landon ; comprising the Impro- 
 visatrice, the Venetian Bracelet, the Golden 
 Violet, the Troubadour, and Poetical Remains. 
 New Edition ; with 2 Vignettes by R. Doyle. 
 2 vols. IGrno. 10s. cloth ; morocco, 21s. 
 
 Dr. John Lindley's Theory and Practice 
 
 of Horticulture ; or, an Attempt to explain 
 the principal Operations of Gardening upon 
 Physiological Grounds : Being the Second 
 Edition of the Theory of Horticulture, much 
 enlarged ; with 98 Woodcuts. 8vo. 21s. 
 
 Dr. John Lindley's Introduction to 
 
 Botany. New Edition, with Corrections and 
 copious Additions. 2 vols. 8vo. with Six 
 Plates and numerous Woodcuts, price 24s. 
 
 Dr. John Lindley's Synopsis of the 
 
 British Flora arranged according to the 
 Natural Orders; containing Yasculares or 
 Flowering Plants. Third Edition (reprinted) . 
 Fcp. 8vo. 6s. 
 
 Linwood. Anthologia Oxoniensis, sive 
 
 Florilegium e Lusibus poeticis diversorum 
 Oxoniensium Graecis et Latinis decerptum. 
 Curante GULIELMO LINWOOD, M.A., ^Edis 
 Christi Alumno. 8vo. price 14s. 
 
 Lorimer's (C.) Letters to a Young Master 
 
 Mariner on some Subjects connected with 
 his Calling. New Edition. Fcp. 8vo. 5s. 6d. 
 
 London's Encyclopaedia of Agriculture : 
 
 Comprising the Theory and Practice of the 
 Valuation, Transfer, Laying-out, Improve- 
 ment, and Management of Landed Property, 
 and of the Cultivation and Economy of the 
 Animal and Vegetable Productions of Agri- 
 culture. New and cheaper Edition; with 
 1,100 Woodcuts. 8vo. 31s. 6d. 
 
 London's Encyclopaedia of Gardening: 
 
 Comprising the Theory and Practice of Hor- 
 ticulture, Floriculture, Arboriculture, and 
 Landscape. Gardening. With many hundred 
 Woodcuts. Corrected and improved by 
 MBS. LOUDON. New and cheaper Edition. 
 8vo. 31s. 6d. 
 
 London's Encyclopaedia of Trees and 
 
 Shrubs, or Arboretum et Fruticetum Britan- 
 nicum abridged : Containing the Hardy Trees 
 and Shrubs of Great Britain, Native and 
 Foreign, Scientifically and Popularly De- 
 scribed. With about 2,000 Woodcuts. 
 8vo. price 50s. 
 
 London's Encyclopaedia of Plants : Com- 
 prising the Specific Character, Description, 
 Culture, History, Application in- the Arts, 
 and every other desirable Particular respect- 
 ing all the Plants found in Great Britain. 
 New Edition, corrected by MRS. LOUDON. 
 With upwards of 12,000 Woodcuts. 8vo. 
 3. 13s. 6d. Second Supplement, 21s. 
 
 London's Encyclopaedia of Cottage, 
 
 Farm, and Villa Architecture and Furniture. 
 New Edition, edited by MBS. LOUDON ; with 
 more than 2,000 Woodcuts. 8vo. 63s. 
 
 London's Hortus Britannicus ; or, Cata- 
 logue of all the Plants found in Great 
 Britain. New Edition, corrected by MBS. 
 LOTJDON. 8vo. 31s. 6d. 
 
 Mrs. Loudon's Lady's Country Compa- 
 nion ; or, How to Enjoy a Country Life 
 Rationally. Fourth Edition, with Plates 
 and Woodcuts. Fcp. 8vo. 5s. 
 
 Mrs. Loudon's Amateur Gardener's 
 
 Calendar, or Monthly Guide to what should 
 be avoided and done in a Garden. New 
 Edition . Crown 8ro. with Woodcuts, 7s. 6d. 
 
 Low'sElements of Practical Agriculture; 
 
 comprehending the Cultivation of Plants, the 
 Husbandry of the Domestic Animals, and 
 the Economy of the Farm. New Edition ; 
 with 200 Woodcuts. 8vo. 21s. 
 
 Macaulay. Speeches of the Right Hon. 
 
 Lord Macaulay. Corrected by HIMSELF. 
 8vo. price 12s. Lord Macaulay's Speeches 
 on Parliamentary Refonn, 16mo. price Is. 
 
 Macaulay. The History of England 
 
 from the Accession of James II. By 
 the Right Hon. LORD MACATJLAY. New 
 Edition. VOLS. I. and II. 8vo. price 32s. j 
 VOLS. III. and IV. price 36s. 
 
 Lord Macaulay's History of England 
 
 from the Accession of James II. New 
 Edition of the first Four Volumes of the 
 8vo. Edition, revised and corrected. 7 vols. 
 post 8vo. price 6s. each. 
 
 Lord Macaulay's Critical and Historical 
 
 Essays contributed to The Edinburgh 
 Review. Four Editions, as follows : 
 
 1. A LIBRARY EDITION- (the Ninth), in 3 TO!S. STO. 
 price 36s. 
 
 . Complete in ONE VOLUME, with Portrait and Vig- 
 nette. Square crown 8ro. price 21s. cloth ; or 
 80s. calf. 
 
 8. Another NEW EDITION, in 8 vols. fop. 8vo. price 
 21s. cloth. 
 
 4. The PEOPLE'S EDITION, in 2 vols. crown STO. price 
 8s. cloth. 
 
14 
 
 NEW WORKS AND NEW EDITIONS 
 
 Macaulay. Lays of Ancient Rome, with 
 
 Ivry and the Armada. By the Right 
 Hon. LORD MACATTLAY. New Edition. 
 16mo. price 4s. 6d. cloth; or 10s. 6d. 
 bound in morocco. 
 
 Lord Macaulay's Lays of Ancient Rome. 
 
 With numerous Illustrations, Original and 
 from the Antique, drawn on Wood by 
 G-eorge Scharf, jun., and engraved by Samuel 
 Williams. New Edition. Fcp. 4to. price 
 21s. boards ; or 42s. bound in morocco. 
 
 Mac Donald. Poems. By George 
 
 MAC DONALD, Author of Within and With- 
 out. Fcp. 8vo. 7s. 
 
 Mac Donald. Within and Without : A 
 Dramatic Poem. By GEORGE MAC DONALD. 
 Second Edition, revised. Fcp. 8vo. 4s. 6d, 
 
 MacDougall. The Theory of War illus- 
 trated by numerous Examples from His- 
 tory. By Lieutenant -Colonel MACDOUGALL, 
 Commandant of the Staff College. Second 
 Edition, revised. Post 8vo. with 10 Plans 
 of Battles, price 10s. 6d. 
 
 MacDougall. - The Campaigns of Hannibal, 
 arranged and critically considered, ex- 
 pressly for the use of Students of Military 
 History. By Lieut.-Col. P. L. MACDOUGALL, 
 Commandant of the Staff College. Post 
 8vo. with Map, 7s. 6d. 
 
 M'Dougall. The Eventful Voyage of 
 
 H.M. Discovery Ship Resolute to the Arctic 
 Regions in Search of Sir John Franklin and 
 the Missing Crews of H.M. Discovery Ships 
 Erebus and Terror, 1852, 1853, 1854. By 
 G-EORGE F. M'DOUGALL, Master. With a 
 coloured Chart ; 8 Illustrations in tinted 
 Lithography ; and 22 Woodcuts. 8vo. price 
 21s. cloth. 
 
 Sir James Mackintosh's Miscellaneous 
 
 Works : Including his Contributions to The 
 Edinburgh Review. Complete in One 
 Volume ; with Portrait and Vignette. 
 Square crown 8vo. 21s. cloth ; or 30s. bound 
 in calf: or in 3 vole. fcp. 8vo. 21s. 
 
 Sir James Mackintosh's History of England 
 from the Earliest Times to the final Esta- 
 blishment of the Reformation. Library Edi- 
 tion, revised. 2 vols. 8vo. 21s. 
 
 M'Culloch's Dictionary, Practical, Theo- 
 retical, and Historical, of Commerce and 
 Commercial Navigation. Illustrated with 
 Maps and Plans. New Edition, revised and 
 adapted to the Present Time ; containing 
 much additional Information. [Just ready. 
 
 M'Culloch's Dictionary, Geographical; 
 
 Statistical, and Historical, of the various 
 Countries, Places, and principal Natural 
 Objects in the World. Illustrated with Six 
 large Maps. New Edition, revised; with a 
 Supplement. 2 vols. 8vo. price 63s. 
 
 Maguire. Rome; its Ruler and its In- 
 stitutions. By JOHN FRANCIS MAG HIKE, 
 M.P. Second Edition, revised and enlarged : 
 with a new Portrait of Pope Pius IX 
 set. 66. Post 8vo. 10s. 6d. 
 
 Mrs. Marcet's Conversations on Natural 
 
 Philosophy, in which the Elements of that 
 Science are familiarly explained. Thirteenth 
 Edition, enlarged and corrected ; with 34 
 Plates. Fcp. 8vo. price 10s. 6d. 
 
 Mrs. Marcet's Conversations on Chemistry 
 in which the Elements of that Science 
 are familiarly explained and illustrated bj 
 Experiments. New Edition, enlarged anr 
 improved. 2 vols. fcp. 8vo. price 14s. 
 
 Marshman. The Life and Times of 
 
 Carey, Marshman, and Ward : Embracing 
 the History of the Serampore Mission 
 By JOHN CLARK MARSHMAN. 2 vols. 8vo 
 price 25s. 
 
 Martineau. Studies of Christianity : 
 
 A Series of Original Papers, now first col- 
 lected or new. By JAMES MARTINEATJ, 
 Crown 8vo. 7s. 6d. 
 
 Martineau. Endeavours after the Christian 
 Life: Discourses. By JAMES MARTINEATJ. 
 2 vols. post 8vo. 7s. 6d. each. 
 
 Martineau. Hymns for the Christian 
 
 Church and Home. Collected and edited by 
 JAMES MARTINEATJ. Eleventh Edition, 12mo. 
 3s. 6d. cloth, or 5s. calf ; Fifth Edition, 32oic . 
 Is. 4d. cloth, or Is. 8d. roan. 
 
 Martineau. Miscellanies : Comprising Essays 
 on Dr. Priestley, Arnold's Life and Corre- 
 spondence, Church and State, Theodore 
 Parker's Discourse of Religion., " Phases of 
 Faith," the Church of England, and tlio 
 Battle of the Churches. By JAMES MAE- 
 
 TINE ATI. Post BVO. 9s. 
 
 Maunder's Scientific and Literary Trea- 
 sury : A new and popular Encyclopaedia of 
 Science and the Belles-Lettres ; including 
 all branches of Science, and every subject 
 connected with Literature and Art. New 
 Edition. Fcp. 8vo. price 10s. cloth ; bound 
 in roan, 12s. j calf, 12s. 6d. 
 
isHED BY LONGMAN, GREEN, AND CO. 
 
 I 
 
 Maunder's Biographical Treasury ; con- 
 sisting of Memoirs, Sketches, and brief 
 Notices of above 12,000 Eminent Persons of 
 All Ages nnd Nations, from tho Earliest 
 Period of History: Forming a complete 
 Popular Dictionary of Universal Biography. 
 Eleventh Edition, revised, corrected, and ex- 
 tended in a Supplement to the Present 
 Time. Fcp. 8vo. 10s. cloth ; bound in roan, 
 12s. ; calf, 12s. 6d. 
 
 Maunder's Treasury of Knowledge, and 
 
 Library of .Reference. Comprising an Eng- 
 lish Dictionary and Grammar, a Universal 
 Gazetteer, a Classical Dictionary, a Chrono- 
 logy, a Law Dictionary, a Synopsis of the 
 Peerage, numerous useful Tables, &c. New 
 Edition, entirely reconstructed and re- 
 printed ; revised and improved by B. B. 
 WOODWARD, B.A. F.S.A. : Assisted by J. 
 MOKRIS, Solicitor, London ; and W. HUGHTSS, 
 F.R.G.S. Fcp. 8vo. 10s. cloth; bound in 
 roan, 12s. ; calf, 12s. 6d. 
 
 Maunder's Treasury of Natural History; 
 
 or, a Popular Dictionary of Animated 
 Nature : In which the Zoological Character- 
 istics that distinguish the different Classes, 
 Genera, and Species, are combined witli a 
 variety of interesting Information illustrative 
 of the Habits, Instincts, and General Eco- 
 nomy of the Animal Kingdom. With 900 
 Woodcuts. New Edition. Fcp. 8vo. price 
 10s. cloth ; roan, 12s. ; calf, 12s. 6d. 
 
 Maunder's Historical Treasury ; com- 
 prising a General Introductory Outline of 
 Universal History, Ancient and Modern, 
 and a Series of separate Histories of every 
 principal Nation that exists ; their Rise, 
 Progress, and Present Condition, the Moral 
 and Social Character of their respective In- 
 habitants, their Religion, Manners and Cus- 
 toms, &c. New Edition ; revised through- 
 out, with a new GENERAL INDEX. Fcp. 8vo. 
 10s. cloth ; roan, 12s. ; calf, 12s. 6d. 
 
 Maunder's Geographical Treasury. 
 
 The Treasury of Geography, Physical, His- 
 torical, Descriptive, and Political ; contain- 
 ing a succinct Account of Every Country in 
 the World : Preceded by an Introductory 
 Outline of the History of Geography; a 
 Familiar Inquiry into the Varieties of Race 
 and Language exhibite4 by different Nations; 
 and a View of the Relations of Geography 
 to Astronomy and Physical Science. Com- 
 pleted by WILLIAM HUGHES, F.R.G.S. New 
 Edition ; with 7 Maps and 16 Steel Plates. 
 Fcp. 8vo. 10*. cloth ; roan, 12s. ; calf, 12s. 6d. 
 
 Mildred Norman the Nazarene. By a 
 WORKING MAN. Crown 8vo. 5s. 
 
 Merivale. A History of the Romans 
 
 under the Empire. By the Rev. CM 
 MERIVALE, B.D., late Fellow of St. John's 
 College, Cambridge. 8vo. with Maps. 
 
 VOLS. I. and If. comprising the History to tho Fall of 
 JuliK* Ccesar. Scwm.l Kdition 28e. 
 
 VOL. III. to the establishment of the Monarchy by Au- 
 gustus. Second Edition 14s. 
 
 Vots. IV. and V. from Augustus to Claudius, B.C. 27 to 
 32fc. 
 
 Vot. VI. from the Reign of Nero, A.D. 54, to the Fall of 
 Jerusalem, A.D. 70 i6g. 
 
 Merivale. The Fall of the Roman Republic : 
 A Short History of the Last Century of 
 the Commonwealth. By the Rev. C. MERI- 
 VALE, B.D. New Edition. 12mo. 7s. 6d. 
 
 Merivale (Miss). Christian Records : 
 
 Short History of Apostolic Age. By L. A. 
 MERIT ALE. Fcp. 8vo. 7s. 6d. 
 
 Miles. The Horse's Foot, and How to 
 
 Keep it Sound. Eighth Edition ; with an 
 Appendix on Shoeing in general, and Hunters 
 in particular, 12 Plates and 12 Woodcuts. 
 By W. MILES, Esq. Imperial 8vo. 12s. 6d. 
 
 V Two Casts or Models of Off Fore Feet, No. 1, Shod for 
 All Purposes, No. 2, Shod tcith Leather, on Mr. Milea's plan, 
 may be had, price 3s. each. 
 
 Miles. A Plain Treatise on Horse-Shooing. 
 By WILLIAM MILES, Esq. With Plates and 
 Woodcuts. New Edition. Post 8vo. 2s. 
 
 Milne^s History of the Church of Christ 
 
 With Additions by the late Rev. ISAAC 
 MILNEB, D.D., F.R.S. A New Edition, 
 revised, with additional Notes by the Rev. 
 T. GBANTHAM, B.D, 4 vols. 8vo. price 52a. 
 
 Minturn. From New York to Delhi by 
 
 way of Rio de Janeiro, Australia, and China. 
 By ROBERT B. MINTTTRN, Jun. With 
 coloured Boute-Map of India. Post 8vo. 
 price 7s. 6d. 
 
 Mollhausen. Diary of a Journey from 
 
 the Mississippi to the Coasts of the Pacific, 
 with a United States Government Expedi- 
 tion. By B. MOLLHATTSEN, Topographical 
 Draughtsman and Naturalist to the Expe- 
 dition. With an Introduction by Baron 
 HTTMBOLDT ; a Map, coloured Illustrations, 
 and Woodcuts. 2 vols. 8vo. 30s. 
 
 James Montgomery's Poetical Works: 
 
 Collective Edition ; with the Author's Auto- 
 biographical Prefaces, complete in One 
 Volume ; with Portrait and Yignette. Square 
 crown 8vo. price 10s. 6d. cloth ; morocco, 
 21s. Or, in 4 vols. fcp. 8vo. with Portrait, 
 and 7 other Plates, price 14s. 
 
16 
 
 NEW WORKS AND NEW EDITIONS 
 
 Moore. The Power of the Soul over the 
 
 Body, considered in relation to Health and 
 Morals. By GEORGE MOORE, M.D. Fifth 
 Edition. Fcp. 8vo. 6s. 
 
 Moore. Man and his Motives. By George 
 MOOEE, M.D. Third Edition. Fcp. 8vo. 6s. 
 
 Moore. The Use of the Body in relation to the 
 Mind. By GEORGE MOOEE, M.D. Third 
 Edition. Fcp. 8vo. 6s. 
 
 Moore. Memoirs, Journal, and Corre- 
 spondence of Thomas Moore. Edited by 
 the Eight Hon. LORD JOHN EUSSELL, M.P. 
 With Portraits and Vignette Illustrations. 
 8 vols. post 8vo. price 10s. 6d. each. 
 
 Thomas Moore's Poetical Works : Com- 
 prising the Author's Autobiographical Pre- 
 faces, latest Corrections, and Notes. Various 
 Editions of the separate Poems and complete 
 Poetical Works, as follows : 
 
 s. d. 
 
 LALLA ROOKH, 32mo. ruby type 1 
 
 LALLA ROOKH, 16mo. Vignette 2 6 
 
 LALLA ROOKH, square crown 8vo. Plates 15 
 
 LALLA ROOKH, fcp. 4to. with Woodcut Illustra- 
 tions by TENNIEL, in the press. 
 
 IRISH MELODIES, 32mo. ruby type 1 
 
 IRISH MELODIES, 16mo. Vignette 2 6 
 
 IRISH MELODIES, square crown 8vo. Plates 21 
 
 IRISH MELODIES, illustrated by MACLISE, super- 
 royal 8vo 31 6 
 
 SONGS, BALLADS, and SACRED SONGS, 32mo. 
 
 ruby type 2 6 
 
 SONGS, BALLADS, and SACRED SONGS, 16mo. 
 
 Vignette 5 
 
 POETICAL WORKS, People's Edit. 10 PARTS, each 1 
 
 POETICAL WORKS, Cabinet Edition, 10 VOLS. ea. 3 6 
 
 POETICAL WORKS, Traveller's Edit., crown 8vo. 12 6 
 
 POETICAL WORKS, Library Edition, medium 8vo. 21 
 SELECTIONS, entitled " POETRY and PICTURES 
 
 iromTHOMAS MOORE," fcp.dto. with WoodEngs. 21 
 
 MOORE'S EPICUREAN, 16mo. Vignette 5 
 
 Editions printed with the Music. 
 IRISH MELODIES, People's Edition, small 4to. . . 12 
 IRISH MELODIES, imperial. 8vo. small music size 31 6 
 HARMONISED AIRS from IRISH MELODIES, 
 
 imperial 8vo 15 
 
 NATIONAL AIRS, People's Edition, 10 Nos. each. . 1 
 NATIONAL AIRS, imperial 8vo. small music size. . 31 6 
 SACRED SONGS and SONGS from SCRIPTURE, 
 
 imperialSvo 16 
 
 No Edition of Thomas Moore's Poetical 
 Works, or of any separate Poem of Moore's, 
 can be published complete except by Messrs. 
 LONGMAN and Co. 
 
 Morell. Elements of Psychology : Part 
 
 I., containing the Analysis of the Intellectual 
 Powers. By J. D. MOEELL, M.A., One of 
 Her Majesty's Inspectors of Schools. Post 
 8vo. 7s. 6d. 
 
 Morning Clouds. By the Author of 
 
 The Afternoon of Life. Second and cheaper 
 Edition, revised throughout. Fcp. 8vo. 5s. 
 
 Morris (P, 0.) Anecdotes in Natural 
 
 History. By the Rev. F. O. MORRIS, B.A., 
 Hector of Nunburnholme, Yorkshire, Author 
 of " History of the Nests and Eggs of 
 British Birds," &c. Fcp. 8vo. [Just ready. 
 
 Morris (J.) -The Life and Martyrdom 
 
 of St. Thomas Becket, Archbishop of Can- 
 terbury and Legate of the Holy See. By 
 JOHN MORRIS, Canon of Northampton. 
 Post 8vo. 9s. 
 
 Morton. The Resources of Estates : A 
 
 Treatise on the Agricultural Improvement 
 and G-eneral Management of Landed 
 Property. By JOHN LOCKHART MORTON, 
 Civil and Agricultural Engineer ; Author 
 of Thirteen Highland and Agricultui'al 
 Society Prize Essays. With 25 Illustrations 
 in Lithography. Royal 8vo. 31s. 6d. 
 
 Moseley. The Mechanical Principles of 
 
 Engineering arid Architecture. By H. 
 MOSELEY, M.A., F.R.S., Canon of Bristol, 
 &c. Second Edition, enlarged; with nu- 
 merous Corrections and Woodcuts. 8vo. 24s. 
 
 Memoirs and Letters of the late Colonel 
 
 ARMINE MOUNTAIN, Aide-de-Camp to the 
 Q,een, and Adjutant-General of Her Ma- 
 jesty's Forces in India. Edited by Mrs. 
 MOUNTAIN. Second Edition, revised ; with 
 Portrait. Fcp. 8vo. price 6s. 
 
 Mure. A Critical History of the Lan- 
 guage and Literature of Ancient Greece. 
 By WILLIAM MURE, M.P. of Caldwell. 
 Second Edition. VOLS. I. to III. 8vo. price 
 36s. j YOL. IV. price 15s. ; YOL. Y. price 18s. 
 
 Murray's Encyclopaedia of Geography ; 
 
 comprising a complete Description of the 
 Earth : Exhibiting its Relation to the 
 Heavenly Bodies, its Physical Structure, the 
 Natural History of each Country, and the 
 Industry, Commerce, Political Institutions, 
 and Civil and Social State of All Nations. 
 Second Edition ; with 82 Maps, and upwards 
 of 1,000 other Woodcuts. 8vo. price 60s. 
 
 Neale. The Closing Scene ; or, Chris- 
 tianity and Infidelity contrasted in the Last 
 Hours of Remarkable Persons. By the 
 Rev. ERSKINE NEALE, M. A. New Editions. 
 2 vols. fcp. 8vo. price 6s. each. 
 
PUBLISHED BY LONGMAN, GREEN, AM> CO. 
 
 17 
 
 Normanby (Lord). A Year of Revolu- 
 tion. From a Journal kept in Paris in the 
 Year 1848. By the Marquis of NORMANBY, 
 KG. 2 vols. 8vo. 21s. 
 
 Ogilvie. The Master-Builder's Plan; 
 
 or, the Principles of Organic Architecture 
 as indicated in the Typical Forms of Animals. 
 By GEORGE OQILTIE, M.D. Post 8vo. 
 with 72 Woodcuts, price 6s. 6d. 
 
 Oldacre. The Last of the Old Squires, 
 A Sketch. By CEDRIC OLDACRE, Esq., of 
 Sax - Normanbury, sometime of Christ 
 Church, Oxon. Crown 8vo. price 9s. 6d. 
 
 Qsborn. Quedah ; or, Stray Leaves 
 
 from a Journal in Malayan Waters. By 
 Captain SHERARD OSBORN, R.N., C.B., 
 Author of Stray Leaves from an Arctic Jour- 
 nal, &c. With a coloured Chart and tinted 
 Illustrations. Post 8vo. price 10s. 6d. 
 
 Osborn. The Discovery of the North- 
 
 West Passage by H.M.S. Investigator, Cap- 
 tain R. M'CLUBE, 1850-1854. Edited by 
 Captain SHERARD OSBORN, C.B., from the 
 Logs and Journals of Captain R. M'Clure. 
 Third Edition, rerised ; with Additions to 
 the Chapter on the Hibernation of Animals 
 in the Arctic Regions, a Geological Paper 
 by Sir RODERICK I. MURCHISON, a Portrait 
 of Captain M'Clure, a coloured Chart and 
 tinted Illustrations. 8ro. price 15s. 
 
 Owen. Lectures on the Comparative 
 
 Anatomy and Physiology of the Invertebrate 
 Animals, delivered at the Royal College of 
 Surgeons. By RICHARD OWEN, F.R.S., 
 Hunterian Professor to the College. Second 
 Edition, with 235 Woodcuts. 8vo. 21s. 
 
 Professor Owen's Lectures on the Comparative 
 Anatomy and Physiology of the Vertebrate 
 Animals, delivered at the Royal College of 
 Surgeons in 1844 and 1846. With numerous 
 Woodcuts. VOL. I. 8vo. price 14s. 
 
 Memoirs of Admiral Parry, the Arctic 
 
 Navigator. By his Son, the Her. E. PARRY, 
 M.A. of Balliol College, Oxford ; Domestic 
 Chaplain to the Lord Bishop of London. 
 Sixth Edition ; with a Portrait and coloured 
 Chart of the North-West Passage. Fcp. 
 8ro. price 5s. 
 
 Pattison. The Earth and the Word; 
 
 or, Geology for Bible Students. By S. R. 
 PATTISON, F.G.S. Fcp. 8vo. with coloured 
 Map, 3s. 6d. 
 
 Peaks, Passes, and Glaciers : a Series of 
 
 Excursions by 
 
 F. V. HAWKINS, M.A. 
 T. W. HINCHUFF, M.A. 
 E. S. KBNNBDY, B.A. 
 W. MATHBWS, Jun., M.A. 
 A. C. RAMSAY, F. K S 
 A. WILLS, of the Middle Tem- 
 ple, Barrister-at-Law, and 
 J. TYNDALL, F.B.S. 
 
 E.L.AMES, M.A. 
 E. ANDBBSOW, 
 J. BALL, M.R.I.A. 
 C. H. BUKBUEY, M.A. 
 Rev. J. LL. DAVIES, M.A. 
 R. W. E. FORSTBH, 
 Kev. J. F. HABDY, B.D. 
 
 Edited by JOHN BALL, M.R.I.A., F.L.S., 
 President of the Alpine Club. Second 
 Edition ; with 8 Illustrations in Chromo- 
 lithography, 8 Maps illustrative of the 
 Mountain-Explorations described in the 
 volume, a Map illustrative of the Ancient 
 Glaciers of part of Caernarvonshire, various 
 Engravings on Wood, and several Diagrams. 
 Square 'crown 8vo. 21s. 
 
 * # * The EIGHT Swiss MAPS, accompanied 
 by a Table of the HEIGHTS of MOUNTAINS, 
 may be had separately, price 3s. 6d. 
 
 Dr. Pereira's Elements of Materia 
 
 Medica and Therapeutics. Third Edition^ 
 enlarged and improved from the Author's 
 Materials, by A. S. TAYLOR, M.D., and 
 G. O. REES, M.D. : With numerous Wood- 
 cuts. VOL. I. 8vo. 28s. ; VOL. II. PART I. 
 21s. j VOL. II. PART II. 26s. 
 
 Dr. Pereira's Lectures on Polarised Light, 
 together with a Lecture on the Microscope. 
 2d Edition, enlarged from Materials left by 
 the Author, by the Rev. B. POWELL, M.A., 
 &c. Fcp. 8vo. with Woodcuts, 7s. 
 
 Perry. The Franks, from their First 
 
 Appearance in History to the Death of King 
 Pepin. By WALTER C. PERRY, Barrister- 
 at-Law, Doctor in Philosophy and Master 
 of Arts in the University of Gottingen. 
 8vo. price 12s. 6d. 
 
 Peschel's Elements of Physics. Trans- 
 lated from the German, with Notes, by 
 E. WEST. With Diagrams and Woodcuts. 
 3 vols. fcp. 8vo. 21s. 
 
 Phillips's Elementary Introduction to 
 
 Mineralogy. A New Edition, with extensive 
 Alterations and Additions, by H. J. BROOKE, 
 F.R.S., F.G.S. j and W. H. MILLER, M.A., 
 F.G.S. With numerous Wood Engravings. 
 Post 8vo. 18s. 
 
 Phillips. A Guide to Geology. By John 
 PHILLIPS, M.A., F.R.S., F.G.S., &c. Fourth 
 Edition, corrected to the Present Time ; 
 with 4 Plates. Fcp. 8vo. 5s. 
 
18 
 
 fiW WORKS A:ND NEW EDITIONS 
 
 Piesse's Chymical, Natural, and Physi- 
 cal Magic, for the Instruction and Enter- 
 tainment of Juveniles during the Holiday 
 Vacation. With 30 Woodcuts and an In- 
 visible Portrait of the Author. Fcp. 8vo. 
 3s. 6d. harlequin cloth. 
 
 Piesse's Art of Perfumery, and Methods 
 
 of Obtaining the Odours of Plants : With 
 Instructions for the Manufacture of Perfumes 
 for the Handkerchief, Scented Powders, 
 Odorous Vinegars, Dentifrices, Pomatums, 
 Cosmetiques, Perfumed Soap, &c. ; and an 
 Appendix on the Colours of Flowers, Arti- 
 ficial Fruit Essences, &c. Second Edition^ 
 revised and improved ; with 46 Woodcuts. 
 Crown SFO. 8s. 6d. 
 
 Pitt. How to Brew good Beer : a com- 
 plete Guide to the Art of Brewing Ale, 
 Bitter Ale, Table Ale, Brown Stout, Porter, 
 and Table Beer. To which are added Prac- 
 tical Instructions for making Malt. By 
 JOHN PITT, Butler to Sir William E. P. 
 Geary, Bart. Fcp. 8vo. 4s. 6d. 
 
 Porter. History of the Knights of 
 
 Malta, or the Order of the Hospital of St. 
 John of Jerusalem. By Major WHITWORTH 
 POBTER, Royal Engineers. With 5 Illus- 
 trations. 2 vols. 8vo. 24s. 
 
 Powell. Essays on the Spirit of the 
 
 Inductive Philosophy, the Unity of Worlds, 
 and the Philosophy of Creation. By the 
 BCV.BADEN POWELL, M.A.,F.E.S.,F.E.A.S., 
 F.G.S., Savilian Professor of Geometry in the 
 University of Oxford. Second Edition, re- 
 vised. Crown 8vo. with Woodcuts, 12s. 6d. 
 
 Christianity without Judaism: A Second Series 
 of Essays on the Unity of Worlds and of 
 Nature/ By the Eev. BADEN POWELL, M.A., 
 &c. Crown 8vo. 7s. 6d. 
 
 The Order of Nature considered in reference to 
 the Claims of Eevelation : A Third Series 
 of Essays on the Unity of Worlds and of 
 Nature. By the Eev. BADEN POWELL, 
 M.A., &c. Crown 8vo. 12s. 
 
 Pycroft, The Collegian's Guide ; or, 
 
 Eecollections of College Days : Setting forth 
 the Advantages and Temptations of a Uni- 
 versity Education. By the Eev. J. PYCKOFT, 
 B.A. Second Edition. Fcp. 8vo. 
 
 Pycroft' s Course of English Beading, adapted 
 to every taste and capacity ; or, How and 
 What to Eead : With Literary Anecdotes. 
 New Edition. Fcp. 8vo. price 5s. 
 
 Pycroft's Cricket-Field; or, tha Science and 
 History of the Game of Cricket. Third 
 Edition, greatly improved ; with Plates and 
 Woodcuts. Fcp. 8vo. price 5s. 
 
 Quatrefages (A. De). Rambles of a 
 
 Naturalist on the Coasts of France, Spain, 
 and Sicily. By A. Da Q.UATBEFAG-ES. 
 Member of the Institute. Translated b\ 
 E. C. OTTE. 2 vols. post 8vo. 15s. 
 
 Raikes (T.) Portion of the Journal kep 1 !; 
 
 by THOMAS EAIKES, Esq., from!831 to 1847 
 Comprising Eeminiscences of Social am 
 Political Life in London and Paris during 
 that period. New Edition, complete ii 
 2 vols. crown 8vo. with 3 Portraits, prior 
 12s. cloth. 
 
 Rich's Illustrated Companion to tho 
 
 Latin Dictionary and Greek Lexicon : Form 
 ing a Glossary of all the Words representing 
 Visible Objects connected with the Art*, 
 Manufactures, and E very-Day Life of th> 
 Ancients. With about 2,000 Woodcut? 
 from the Antique. Post 8vo. 21s. 
 
 Richardson. Fourteen Years' Expe- 
 rience of Cold Water : Its Uses and Abuses. 
 By Captain M. RICHARDSON, late of the 
 4th Light Dragoons. Post 8vo. with 
 Woodcuts, price 6s. 
 
 Horsemanship ; or, the Art of Riding 
 
 and Managing a Horse, adapted to the Guid- 
 ance of Ladies and Gentlemen on the Road 
 and in the Field : With Instructions for 
 Breaking-in Colts and Young Horses. By 
 Captain M. EICHARDSON, late of the 4th 
 Light Dragoons. With 5 Plates. Square 
 crown 8vo. 14s. 
 
 Riddle's Copious and Critical Latin- 
 English Lexicon, founded on the German- 
 Latin Dictionaries of Dr. William Freund. 
 New Edition. Post 4to. 31s. 6d. 
 
 Riddle's Complete Latin-English and 
 
 English-Latin Dictionary, for the use of 
 Colleges and Schools. By the Eev. J. E. 
 EIDDLE, M.A, of St. Edmund Hall, Oxford. 
 New and cheaper Edition, revised and cor- 
 rected. 8vo. 21s. 
 
 , , /The English-Latin Dictionary, 7s. 
 Separately | The Lat i n -English Dictionary, 15s. 
 
 Riddle's Young Scholar's Latin-English 
 
 and English-Latin Dictionary. New and 
 cheaper Edition, revised and corrected. 
 Square 12mo. 10s. 6d. 
 
 a . , r /The Latin-English Dictionary, 6s. 
 
 Separately | Tne English-Latin Dictionary, 5s. 
 
 Kiddle's Diamond Latin-English Dictionary. 
 A Guide to the Meaning, Quality, ai d 
 right Accentuation of Latin Classical Words. 
 Royal 32mo. price 4s. 
 
PUBLISHED BY LONGMAN, GREEN, AKD CO. 
 
 ifl 
 
 Rivers's Rose -Amateur's Guide ; contain- 
 ing ample Description? of nil the fine leading 
 yarieties of Roses, regularly classed in their 
 respective Families ; their History and 
 Mode of Culture. Fcp. 8vo. 3s. 6d. 
 
 r. E. Robinson's Greek and English 
 
 Lexicon to the Greek Testament. A New 
 Edition, in great port re-written. 8vo. 18s. 
 
 r. Henry Rogers's Essays selected from 
 
 Contributions to the Edinburgh Review. 
 
 amuel Rogers's Recollections of Per- 
 sonal and Conversational Intercourse with 
 
 r. Roget's Thesaurus of English Words 
 
 and Phrases classified and arranged so as to 
 facilitate the Expression of Ideas and assist 
 in Literary Composition. Eighth Edition, 
 revised and improved. Crown 8vo. 10s. 6d. 
 
 onalds's Fly-Fisher's Entomology : 
 
 With coloured Representations of the 
 Natural and Artificial Insect, and a few Ob- 
 servations and Instructions on Trout and 
 Grayling Fishing. Fifth Edition, thoroughly 
 revised by an Experienced Fly-Fisher ; with 
 20 new coloured Plates. 8vo. 14s. 
 
 >wton's Debater: A Series of complete 
 
 Debates, Outlines of Debates, and Questions 
 tor Discussion; with ample References lo the 
 best Sources of Information. New Edition. 
 Fcp. 8vo. 6s. 
 
 ussell (Dr.) The Life of Cardinal 
 
 Mezzofanti : With an Introductory Memoir 
 of eminent Linguists, Ancient and Modern. 
 By C. W. RUSSELL, D.D., President of St. 
 Patrick's College, Maynooth. With Portrait 
 r.d Facsimiles. 8vo. 12s. 
 
 herzer. Travels in the Free States of 
 
 ientral America : Nicaragua, Honduras, 
 and San Salvador. By Dr. CARL SCHEHZEB. 
 With a coloured Map. 2 vols. posOBvo. 16s. 
 
 Second Jidition. 3 v 
 1. Thomas Fuller. 
 _'. Andrew Mary ell. 
 ; in Luther. 
 nit/. 
 .-,. Pascal. 
 6. Plato and Socrates. 
 7. Descartes. 
 8. John Locke. 
 9. Sydney Smith's Lec- 
 tures. 
 10. English Language 
 (Structure). 
 11. English Language 
 
 12. The British Pulpit. 
 
 ols. icp. 8vo. price 21s. 
 13. Vanity and Glory of 
 Literature. 
 14. I'll rainontane Doubts. 
 15. Right of Private Judg- 1 
 ment. 
 16. The Oxford Tractarian 
 Schools. 
 17. Recent Developments 
 of Tracoariamsm. 
 18. Reason and Faith. 
 1'J. Revolution and Re- 
 form. 
 20. Treatment of Crimi- | 
 nals. 
 21. Prevention of Crime. 
 
 JHARLES JAMES Fox, 
 SDMCND BUHKE, 
 [ENKY GRATTAN, 
 RICHARD PORSON, 
 0HN HOBXE TOOKE, 
 
 Second Edition* Fc 
 
 PHIITCB TALLEY^AUD, 
 LOUD ERSKINE, 
 SIH WALTEB SCOTT, 
 LORD GRBNVLLLB, and 
 DUKE OF WELLINGTON. 
 
 p. 8vo. 5s. 
 
 Mrs. SchimmelPenninck's Writings and 
 
 Life, edited by her relation, CHUISTIANA C. 
 HANKIN : 
 
 Life of Mary Anne SchimmelPenninck. Third 
 and cheaper Edition, with Corrections and 
 Additions ; complete in One Volume, with 
 Portrait Post 8vo. 10*. 6d. 
 
 Select Memoirs of Port-Royal. To which are 
 added Tour to Alet, Visit to Port-Royal, 
 Gift of an Abbess, Biographical Notices, &c. 
 from original Documents. Fifth Edition, 
 revised 3 vols, poet8vo.21*. 
 
 The Principles of Beauty, as manifested 
 Nature, Art, and Human Character : with 
 a Classification of Deformities ; II. An 
 Essay on the Temperaments (with Illus- 
 trations) ; III. Thoughts on Grecian and. 
 Gothic Architecture Post 8vo. 12$, Qd. 
 
 Dr. L, Schmitz's School History of Greece, 
 
 from the Earliest Times to the Taking of 
 Corinth by the Romans, B.C. 146, mainly 
 based on Bishop Thirlwali's History of 
 Greece. Fifth Edition, with Nine new Sup- 
 plementary Chapters on the Civilisation 
 Religion, Literature, and Arts of the An- 
 cient Greeks, contributed by CHRISTOPHER 
 KNIGHT WATSON, M.A., Trin. Coll. Camb. ; 
 and illustrated with a Map of Athens and 137 
 Woodcuts, designed from the Antique by 
 G. Scharf, jun., F.S.A. 12mo. 7s. 6d. 
 
 Scoffern (Dr.) Projectile Weapons of 
 
 War and Explosive Compounds. By J. 
 SCOFFEEN, M.B. Lond., late Professor of 
 Chemistry in the Aldersgate College of 
 Medicine. Fourth Edition, brought up to the 
 present time in a Supplement. Post 8vo. 
 with Woodcuts, 9s. 6d. 
 SUPPLEMENT, containing new resources of 
 Warfare 2s. 
 
 Senior. Journal kept in Turkey and 
 
 Greece in the Autumn of 1857 and the 
 beginning of 1858. By NASSAU W. SENIOB, 
 Esq. With 2 Maps and 2 Views in chromo- 
 lithography. Post 8vo. 123. 
 
 Bowdler's Family Shakspeare : In which 
 
 nothing is added to the Original Text ; but 
 those words and expressions are omitted 
 which cannot with propriety be read aloud. 
 Illustrated with Thirty-six; Vignettes en- 
 graved on Wood from original Designs by 
 
 Q. COOKB, B.A. T. STOTHARD, B.A, 
 
 B. COOKE, H. THOMSON, B.A, 
 
 H. HOWARD, B.A. B. WESTALL, B.A. 
 
 H. SINGLETON, B. WOKDFOKDE, B.A. 
 B. SUIBKE, B.A. 
 
 New Edition, printed in a more convenient 
 form. 6 vols. fcp. 8vo. price 30s. cloth; 
 separately, 5s. each. 
 
 %* The LIBRARY EDITION, with the same 
 Illustrations, in One Volume, medium 8vo. 
 price 21s. cloth. 
 
20 
 
 NEW WORKS AND NEW EDITIONS 
 
 Sewell (Miss). New and cheaper Col- 
 lected Edition of the Tales and Stories of 
 the Author of Amy Herbert. Complete in 
 9 vols. crown 8vo. price 1. 10s. cloth ; or 
 each work, comprised in a single volume, 
 may be had separately as follows : 
 
 AMYHERBERT 2s. 6d. 
 
 GERTRUDE 2s. 6d. 
 
 The EARL'S DAUGHTER 2s. 6d. 
 
 The EXPERIENCE of LIFE 2s. 6d. 
 
 CLEVE HALL 3s. 6d. 
 
 IVORS; or, the TWO COUSINS 3s. 6d. 
 
 KATHARINE ASHTON 3s. 6d. 
 
 MARGARET PERCIVAL 5s. Od. 
 
 LANETON PARSONAGE .. 4s. 6d. 
 
 "mO the thoroughness 
 A and integrity, the ab- 
 solute rectitude inculcated 
 in thought, word, and deed, 
 and to the tender charity ex- 
 tended to the erring and re- 
 pentant, we are inclined to 
 attribute the hold these 
 works take on readers of all 
 classes and all ages. The 
 
 pure transparent sincerity 
 tells even on those who are 
 apt to find any work whose 
 aim and object are religious, 
 heavy and uninteresting. 
 The re-publication of these 
 worJcs in an easily accessible 
 form is a benefit of which we 
 cannot over-estimate the solid 
 advantages." GLOBE. 
 
 Also ly the Author of Amy Herbert, 
 
 Ursula : A Tale of English Country Life. 
 
 2 yols. fcp. 8vo. price 12s. cloth. 
 History of the Early Church, from the 
 
 First Preaching of the Gospel to the Council 
 of Nicea. 18mo. 4s. 6d. 
 
 Self-Examination before Confirmation: 
 
 With Devotions and Directions for Con- 
 firmation-Day. 32mo. Is. 6d. 
 
 Readings for a Month preparatory to 
 
 Confirmation : Compiled from the Works of 
 Writers of the Early and of the English 
 Church. Fcp. 8vo. price 4s. 
 
 Headings for Every Day in Lent : Com- 
 piled from the Writings of BISHOP JEBEMY 
 TAYLOE. Fcp. 8vo. price 5s. 
 
 Sharp's New British Gazetteer, or Topo- 
 graphical Dictionary of the British Islands 
 and Narrow Seas : Comprising concise De- 
 scriptions of about Sixty Thousand Places, 
 Seats, Natural Features, and Objects of Note, 
 founded on the best authorities. 2 vols. 
 8vo. price 2. 16s. 
 
 Short Whist ; its Rise, Progress, and 
 
 Laws : With Observations to make any one a 
 Whist-Player. Containing also the Laws of 
 Piquet, Cassino, Ecarte, Cribbage, Back- 
 gammon. By Major A. New Edition ; to 
 which are added, Precepts for Tyros, by 
 Mrs. B. Fcp.Svo. 3s. 
 
 Simpson. Handbook of Dining; or, 
 
 to Dine, theoretically, philosophically, t.nc 
 historically considered : Based chiefly uf OD: 
 the Physiohgie du Gout of Brillat-Savaiini 
 By LEONAED FEANCIS SIMPSON, M.R 
 Fcp. 8vo. 5s. 
 
 Sinclair. The Journey of Life. 
 CATHEEINE SINCLAIE, Author of The 
 ness of Life. New Edition. Fcp. 8vo. 5s 
 
 Sir Roger De Coverley. From the Spec 
 
 tator. With Notes and Illustrations, bj 
 W. HENEY WILLS ; and 12 Wood Eng:*a\ 
 ings from Designs by F. TATLEE. Secon 
 and cheaper Edition. Crown 8vo. 10s. (;d.| 
 or 21s. in morocco by Hayday. AnEdiic 
 without Woodcuts, in 16mo. price Is. 
 
 The Sketches: Three Tales. By th 
 
 Authors of Amy Herbert, The Old 
 Home, and Hawkstone. Third Edition ; wil 
 6 Illustrations. Fcp. 8vo. price 4s. 6d. 
 
 Smee's Elements of Electro-Metallurg 
 
 Third Edition, revised, corrected, and co 
 sider ably enlarged ; with Electrotypes ai 
 numerous Woodcuts. Post 8vo. 10s. 6d. 
 
 Smith (G.) History of Wesleyan M 
 
 thodism. By GEOEGE SMITH, F.Aj 
 Member of the Koyal Asiatic Society, 
 VOL. I. Wesley and his Times; and Yc 
 II. The Middle Age of Methodism, from 1 
 Death of Wesley in 1791 to the Confi 
 ence of 1816. Crown 8vo. price 10s. ( 
 each volume. 
 
 Smith (J.) -The Voyage and Shipwre l 
 
 of St. Paul : With Dissertations on the I If 
 and Writings of St. Luke, and the Ships a 
 Navigation of the Ancients. By JAM 
 SMITH, of Jordanhill, Esq., F.E.S. Stco j 
 Edition ; wilh Charts, Yiews, and Woe 
 cuts. Crown 8vo. 8s. 6d. 
 
 A Memoir of the Rev. Sydney Smiirj 
 
 By his Daughter, LADY HOLLAND. W 
 a Selection from his Letters, edited 
 MES. AUSTIN. New Edition. 2voLs.8vo.2 
 
 The Rev. Sydney Smith's Miscellaneo 
 
 Works : Including his Contributions to 1 
 Edinburgh Review. Four Editions : 
 
 1. A LIBEAEY EDITION (the Fourth), ir 
 vols. 8vo. with Portrait, 36s. 
 
 2. Complete in ONE YOLUME, with Porti 
 and Yignette. Square crown 8vo. p) 
 21s. cloth ; or 30s. bound in calf. 
 
 3. Another NEW EDITION, in 3 vols. 
 8vo. price 21s. 
 
 4. The PEOPLE'S EDITION, in 2 vols.'cro 
 8vo. price 8s. cloth. 
 
PUBLISHED BY LONGMAN, GREEN, AND CO. 
 
 21 
 
 'he Rev. Sydney Smith's Elementary 
 
 Sketches of Moral Philosophy, delivered at 
 the Royal Institution in the Years 1804, 
 1805,andl806. Third Edition. Fcp.8ro.7s. 
 
 now. Two Years' Cruise off Tierra 
 
 del Fiiego, the Falkland Islands, Patagonia, 
 and the River Plate : A Narrative of Life 
 in the Southern Seas. By W. PARKER 
 SNOW, late Commander of the Mission 
 Yacht Allen Gardiner ; Author of " Voyage 
 of the Prince A/brrt in Search of Sir John 
 Franklin." With 3 coloured Charts and 6 
 tinted Illustrations. 2 vols. post 8vo. 24s. 
 
 obert Southey's Complete Poetical 
 
 Works ; containing all the Author's last In- 
 troductions and Notes. The Library Edi- 
 tion, complete in One Volume, with Por- 
 trait and Vignette. Medium 8vo. price 21s. 
 cloth ; 42s. bound in morocco. Also, the 
 First collected Edition, in 10 vols. fcp. 8vo. 
 with Portrait and 19 Vignettes, price 35s. 
 
 outhey's Doctor, complete in One 
 Volume. Edited by the Rev. J. W. WARTER, 
 B.D. With Portrait, Vignette, Bust, and 
 coloured Plate. Square crown 8vo. 21s. 
 
 outhey's Life of Wesley ; and Rise and 
 
 Progress of Methodism. Fourth and cheaper 
 Edition, with Notes and Additions. Edited 
 by the Author's Son, the Rev. C. C. 
 SOUTHEY, M.A. 2 vols. crown 8vo. 12s. 
 
 pencer. Essays : Scientific, Political, 
 
 and Speculative. By HERBERT SPENCER, 
 Author of Social Statics, Reprinted chiefly 
 from Quarterly Reviews. 8vo. price 12s.cloth. 
 
 jencer. The Principles of Psychology. By 
 HERBERT SPENCER, Author of Social Statics. 
 8vo. price 16s. cloth. 
 
 ;ephen. Lectures on the History of 
 France. By the Right Ho*. SIR JAMES 
 STEPHEN,K.C.B.,LL.D.,Professor of Modern 
 History in the University of Cambridge. 
 Third Edition. 2 vols. 8vo. price 24s. 
 
 tephen. Essays in Ecclesiastical Bio- 
 graphy ; from the Edinburgh Review. By 
 theRight Hon. SIR JAMES STEPHEN, K.C.B., 
 LL.D., Professor of Modern History in 
 the University of Cambridge. Third Edi- 
 tion. 2 vols. 8vo. 24s. 
 
 Hildebrand. 
 
 Saint Francis of Assisi. 
 The Founders of Jesuit- 
 
 sm. 
 
 Martin Luthev. 
 The Freuch Benedic- 
 tines. 
 The Port Royalist?. 
 
 7. Richard Baxter. 
 
 8. The Evangelical Suc- 
 cession. 
 
 9. William Wilberforce. 
 
 10. The Clapham Sect. 
 
 11. The Historian of En- 
 thusiasm. 
 
 12. The Epilogue. 
 
 Stonehenge. The Dog in Health and 
 
 Disease : Comprising the Natural History, 
 Zoological Classification, and Varieties of 
 the Dog, as well as the various Modes of 
 Breaking and Using him for Hunting, 
 Coursing, Shooting, &c. ; and including the 
 Points or Characteristics of Toy Dogs. By 
 STONEHENGE. With about 70 Illustrations 
 engraved on Wood. Square crown 8vo. 
 price 15,y. half-bound. 
 
 Stonehenge's Work on the Greyhound : Being a 
 Treatise on the Art of Breeding, Rearing, 
 and Training Greyhounds for Public Run- 
 ning ; their Diseases and Treatment : Con- 
 taining also Rules for the Management of 
 Coursing Meetings, and for the Decision of 
 Courses. With Frontispiece and Woodcuts. 
 Square crown 8vo. 21s. 
 
 Stow. The Training System of Educa- 
 tion ; including Moral School Training for 
 large Towns, and the Normal Seminary for 
 Training Teachers to conduct the System. 
 By DAVID STOW, Esq., Honorary Secretary 
 to the Normal Seminary, Glasgow. Eleventh 
 Edition, enlarged ; with Plates and Wood- 
 cuts. Post 8vo. price 6s. 6d. 
 
 Strickland. Lives of the Queens of 
 
 England. By AGNES STRICKLAND. Dedi- 
 cated, by express permission, to Her Ma- 
 jesty. Embellished with Portraits of every 
 Queen, engraved from the most authentic 
 sources. Complete in 8 vols. post 8vo. price 
 7s. 6d. each. Any Volume may be had 
 separately to complete Sets. 
 
 Memoirs of Rear-Admiral Sir William 
 
 Symonds, Knt., C.B., F.R.S., Surveyor of 
 the Navy, from 1832 to 1847 : With Cor- 
 respondence and other Papers relative to 
 the Ships and Vessels constructed upon his 
 Lines, as directed to be published under his 
 Will. Edited by JAMES A. SHARP. With 
 Sections and Woodcuts. 8vo. price 21s. 
 
 Taylor. Loyola : and Jesuitism in its 
 Rudiments. By ISAAC TAYLOR. Post 8vo. 
 with Medallion, 10s. 6d. 
 
 Taylor. Wesley and Methodism. By 
 ISAAC TAYLOR. Post 8vo. Portrait, 10s. 6d. 
 
 Tennent. Ceylon : an Account of the 
 
 Island, Physical, Historical, and Topo- 
 graphical : with copious Notices of its 
 Natural History, Antiquities, and Produc- 
 tions. Illustrated by 7 Maps, 17 Plans and 
 Charts, and 101 Engravings on Wood. By 
 Sir J. EMERSON TENNENT, K.C.S., LL.D., 
 &c. 2 vols. 8vo. 
 
JNEVV WORKS AND NEW EDITIONS 
 
 COMPLETION 
 
 THE TRAVELLER'S LIBRARY, 
 
 Summary of tie Contents of the TRAVELLER'S LIBRARY, complete in 102 
 Parts, price One Shilling each, or in 50 Volumes, price 2s. 6d. each in cloth. 
 To be had also, in complete Sets only, at Five Guineas per Set, bound in cloth, 
 lettered, in 25 Volumes, classified as follows : 
 
 VOYAGES AND TRAVELS. 
 
 IN EUROPE. 
 A CONTINENTAL TOUR BY J. BARROW. 
 
 ARCTIC VOYAGES AND \ 
 
 DISCOVERIES / 
 
 BRITTANY AND THE BIBLE BY I. HOPE. 
 
 BRITTANY AND THE CHASE BY I. HOPE. 
 
 CORSICA BY F. GREGOROVIUS. 
 
 GERMANY, ETC. : NOTES OF! __ Q T Arwr , 
 
 A TRAVELLER j .... BY S. LAING. 
 
 ICELAND BY P. MILES. 
 
 NORWAY, A RESIDENCE IN BY S. LAING. 
 
 NORWAY, RAMBLES IN BY T. FORESTER. 
 
 RUSSIA . . . . BY THE MARQUIS DE CUSTINE. 
 RUSSIA AND TURKEY .. BY J. R. M'CULLOCH. 
 
 ST. PETERSBURG BY M. JERRMANN. 
 
 THE RUSSIANS OF THE SOUTH, BY S. BROOKS. 
 SWISS MEN AND SWISS \ __ R pFT?r T T<inAr 
 
 MOUNTAINS , . . J BY K ' FERGUSON. 
 
 MONT BLANC, ASCENT OF BY J.AULDJO. 
 
 SKETCHES OF NATURE 
 
 IN* THE ALPS ... . . 
 VISIT TO THE VAUDOIS1 
 
 OFPIEDMONT .. ../ 
 
 IN ASIA. 
 
 CHINA AND THIBET B Y IHE ABBE' HUC . 
 
 SYRIA AND PALESTINE " EOTHEN." 
 
 THE PHILIPPINE ISLANDS, BY P. GIRONIERE. 
 
 IN AFRICA. 
 AFRICAN WANDERINGS BY M. WERNE . 
 
 MOROCCO . 
 
 BY X. DURRIEU. 
 
 NIGER EXPLORATION . . BY T. J. HUTCHINSON. 
 THE ZULUS OF NATAL BY G. H. MASON. 
 
 IN AMERICA. 
 
 BRAZIL BY E. WILBERFORCE. 
 
 CANADA BY A. M. JAMESON. 
 
 CUBA BY W. H. HURLBUT. 
 
 NORTH AMERICAN WILDS .... BYC.LANMAN. 
 
 IN AUSTRALIA. 
 
 AUSTRALIAN COLONIES BY W. HUGHES. 
 
 ROUND THE WORLD. 
 A LADY'S VOYAGE BY IDA PFEIFFER. 
 
 HISTORY AND BIOGRAPHY. 
 
 MEMOIR OF THE DUKE OF WELLINGTON. 
 THE LIFE OF MARSHAL \ BY THE REV. T. 0. 
 
 TURENNE i COCKAYNE. 
 
 SCHAMYL .... BY BODENSTEDT AND WAGNER 
 FERDINAND I. AND MAXIMI- 1 
 
 LIAN II / 
 
 FRANCIS ARAGO'S AUTOBIOGRAPHY. 
 THOMAS HOLCROFT'S MEMOIRS. 
 
 BY RANKE. 
 
 CHESTERFIELD & SELWYN, BY A. HAYWARD 
 SWIFT AND RICHARDSON, BY LORD JEFFREY 
 DEFOE AND CHURCHILL .... BYJ. FORSTER 
 ANECDOTES OF DR. JOHNSON, BY MRS. PIOZZ1. 
 TURKEY AND CHRISTENDOM. . 
 LEIPSIC CAMPAIGN, BY THE REV. G. R. GLEIG 
 AN ESSAY ON THE LIFE AND! BY HENRY 
 GENIUS OF THOMAS FULLER/ ROGERS. 
 
 ESSAYS BY LORD MACAULAY. 
 
 WARREW HASTINGS. 
 
 LORD CLIVE. 
 
 WILLIAM PITT. 
 
 THE EARL OF CHATHAM. 
 
 RANKE'S HISTORY OF THE POPES. 
 
 GLADSTONE ON CHURCH AND STATE. 
 
 ADDISON'S LIFE AND WRITINGS. 
 
 HORACE WALPOLE. 
 
 LORD BACON. 
 
 LORD BYRON. 
 
 COMIC DRAMATISTS OF THE RESTORATION. 
 FREDERIC THE GREAT. 
 HALLAM'S CONSTITUTIONAL HISTORY. 
 CHOKER'S EDITION OF BOSWELL'S LIFE 
 JOHNSON. 
 
 LORD MACAULAY'S SPEECHES ON PARLIA- 
 MENTARY REFORM. 
 
 ui\ . 
 
 . 
 
 WORKS OF FICTION. 
 
 THE LOVE STORY, FHOH SOUTHEY'S DOCTOR. \ AN ATTIC PHILOSO- 1 
 
 cn> wnawu rur nnvirpT vv \ PKOM THE PHER IN PARIS . . / BT E ' S0m E ^RE. 
 
 SIR ROGER DE COVERLEY. 
 
 PKOM TI 
 
 SPECTATOR. ! SIR EDWARD SEAWARD'S NARRATIVE 0*' 
 MEMOIRS OF A MAITRE-D'ARMES, BY DUMAS. ' HIS SHIPWRECK. 
 CONFESSIONS OF A \ 
 WORKING MAN .. / 
 
 NATURAL HISTORY, &c. 
 
 NATURAL HISTORY OF 1 
 CREATION .............. } 
 
 INDICATIONS OF INSTINCT, BY DR. L. KEMP. 
 
 , T 
 DR - L - 
 
 ELECTRIC TELEGRAPH, &c. BY DR. G.WILSON, 
 OUR COAL-FIELDS AND OUR COAL-PITS. 
 CORNWALL, ITS MINES, MINERS, &c. 
 
 MISCELLANEOUS WORKS. 
 
 LECTURES AND ADDRESSES {**CARIISLE * 
 SELECTIONS FROM SYDNEY SMITH'S 
 
 WRITINGS. 
 PRINTING ... BY A. STARK. 
 
 RAILWAY MORALS AND\ ^ 
 RAILWAY POLICY ...... } . . BY H. 
 
 MORMON1SM . . BY THE REV. W. J. 
 
 LONDON ................ BY J. R. M'CULLOCH. 
 
PUBLISHED BY LONGMA> .-.', AM) CO. 
 
 Thirlwall. The History of Greece. By 
 
 the Eight Rev. the LORD BISHOP of ST. 
 DATID'S (the Rev. Cormop Thirlwall). -8 
 vols. 8vo. with Maps, 3. An Edition in 
 8 vols. fcp. 8vo. with Vignette Titles, 28s. 
 
 Thomson's Seasons. Edited by Bolton 
 
 CORNET, Esq. Illustrated with 77 fine 
 Wood Engravings from Designs by Mem- 
 bers of the Etching Club. Square crown 8vo. 
 21s. cloth ; or 86s. bound in morooeo. 
 
 Thomson (the Rev. Dr.) An Outline of 
 
 the necessary Laws of Thought : A Treatise 
 on Pure and Applied Logic. By WILLIAM 
 THOMSON, D.D., Provost of Queen's College, 
 Oxford. Uh Edition. Fcp. 8vo. 7s. 6d. 
 
 Thomson's Tables of Interest, at Three, 
 
 Four, Four-and-a-Half, and Five per Cent., 
 from One Pound to Ten Thousand, and from 
 1 to 365 Days, in a regular progression of 
 single Days ; with Interest at all the above 
 Rates, from One to Twelve Months, and 
 from One to Ten Years. Also, numerous 
 other Tables of Exchanges, Time, and Dis- 
 counts. New Edition. 12uao. price 8a. 
 
 The Thumb Bible ; or, Verbum Sempi- 
 
 ternum. By J. TAYLOB. Being an Epi> 
 tome of the Old and New Testaments in 
 English Verse. Reprinted from the Edition 
 of 1693 ; bound and clasped. 64mo. Is. 6d. 
 
 Todd (Dr.) The Cyclopsedia of Anatomy 
 
 and Physiology. Edited by ROBERT B. 
 TODD, M.D., F.R.S., &c., Physician to 
 King's College Hospital; late Professor of 
 General and Morbid Anatomy in King's 
 College, London. Assisted in the various 
 departments by nearly all the most eminent 
 cultivators of physiological science of the 
 present age. Now complete in 5 vols. 8vo. 
 pp. 5,350, illustrated with 2,853 Wood- 
 cuts, price 6. 6s. cloth. 
 
 Tooke. History of Prices, and of the | 
 
 State of the Circulation, during the Nine 
 Years from 1848 to 1856 inclusive. Form- 
 ing YOLS. V. and VI. of Tooke's History of 
 Prices from 1792 to the Present Time', and 
 comprising a copious Index to the whole of 
 the Six Volumes. By THOMAS TOOKE, 
 F.R.S. and WILLIAM NEWMARCH. 2 vols. 
 8vo. price 52s. 6d. . 
 
 Trevelyan (Sir C.) Original Papers 
 
 illustrating the History of the Application 
 of the Roman Alphabet to the Languages 
 of India. Edited by MONIER WILLIAMS, 
 M.A., Lite Professor of Sanskrit in the 
 East-India College, Haileybury. 8vo. with 
 Map, 12s. 
 
 Trollope. The Warden : a Novel. By 
 
 A NTHONY TUOLLOPE. New and cheaper Edi- 
 tion. Crown 8vo. price 3s. 6cl. cloth. 
 
 Trollope' s Barchester Towers, a Sequel to the 
 Warden. New and chea|>or Edition, com- 
 plete in One Volume. Crown 8vo. 5s. 
 
 Sharon Turner's History of the Anglo- 
 Saxons, from the Earliest Period to the 
 Norman Conquest. Seventh Edition, revised 
 by the Rev. S. TTJBNEB. 3 vols. 8vo. 36s. 
 
 Dr. Turton's Manual of the Land and 
 
 Fresh- Water Shells of Great Britain : With 
 Figures of each of the kinds. New Edition, 
 with Additions, by Dr. J. E. GRAY, F.R.S. , 
 &c., Keeper of the Zoological Collection in 
 the British Museum. Crown 8vo. with 12 
 coloured Plates, price 15s. cloth. 
 
 Dr. Ure's Dictionary of Arts, Manufac- 
 tures, and Mines : Containing a clear Expo- 
 sition of their Principles and Practice. 
 Fourth Edition, much enlarged ; most of 
 the Articles being entirely re-written, and 
 many new Articles added. With nearly 
 1,600 Woodcuts. 2 vols, 8vo. price 60s. 
 
 Uwins. Memoir and Correspondence of 
 
 Thomas Uwins, R.A., late Keeper of the 
 Royal Galleries and of the National Gallery, 
 &c. Edited by Mrs. UwiNS. 2 vols. post 
 8vo. 18s. 
 
 Van Der Hoeven's Handbook of Zoology. 
 
 Translated by the Rev. WILLIAM CLASS", 
 M.D., F.R.S., &c. Professor of Anatomy 
 in the University of Cambridge. 2 vols. 
 8vo. with 24 Plates of Figures, price 60s. 
 cloth ; or separately, VOL. I. Invertebrate 
 30s., and VOL. II. Vertebrata t 30s. 
 
 Vehse Memoirs of the Court, Aristo- 
 cracy, and Diplomacy of Austria. By Dr. E. 
 VEHSE. Translated from the German by 
 FRANZ DEMMLEB. 2 vols. post 8vo. 21s. 
 
 Von Tempsky. Mitla ; or, Incidents 
 
 and Personal Adventures on a Journey in 
 Mexico, Guatemala, and Salvador, in the 
 Years 1853 to 1855. By G.F. VON TEMPSKY. 
 With Map, Illustrations in colours, and 
 Woodcuts. 8vo. 18, 
 
 Wade. England's Greatness: Its Rise 
 
 and Progress in Government, Laws, Religion, 
 and Social Life; Agriculture, Commerce, 
 and Manufactures ; Science, Litf rature, and 
 the Arts, from the Earliest Period to the 
 Peace of Paris. By JOHN WAI>E, Author of 
 tho Cabinet Lawyer, Ac. Post 8vo, 10s. 6d. 
 
 Wanderings in the Land of Ham. By a 
 DAUGHTER of JAPHET. Post 8vo. 8s. 6d. 
 
24 
 
 NEW WORKS PUBLISHED BY LONGMAN AND CO. 
 
 Waterton. Essays on Natural History, 
 
 chiefly Ornithology. By C. WATERTON, Esq. 
 With the Autobiography of the Author. 
 2 vols. fcp. 8vo. 10s. 
 
 Waterton' s Essays on Natural History. Third 
 Series ; with a Continuation of the Auto- 
 biography, and a Portrait of the Author. 
 Second Edition, Fcp. 8vo. price 6s. 
 
 Watson's Cybele Britannica ; or, British 
 
 Plants and their Geographical Relations. 
 By HEWETT COTTBELL WATSON. 4 vols. 
 8vo. price 42s. cloth ; or each vol. separately, 
 price 10s. 6d. The fourth volume is de- 
 voted to general views and tabular sum- 
 maries, showing the phy to -geography of 
 Britain under various aspects. 
 
 Webb. Celestial Objects for Common 
 
 Telescopes. By the Rev. T. W. WEBB, 
 M.A., F.R.A.S., Incumbent of Hardwick, 
 Herefordshire. With Woodcuts, and a Map 
 of the Moon 12 inches in diameter engraved 
 on Steel. 16mo. 7s. 
 
 Webster and Parkes's Encyclopaedia of 
 
 Domestic Economy ; comprising such sub- 
 jects as are most immediately connected with 
 Housekeeping : As, The Construction of 
 Domestic Edifices, with the Modes of Warm- 
 ing, Ventilating, and Lighting them A de- 
 scription of the various articles of Furniture, 
 with the nature of their Materials Duties of 
 Servants &c. New Edition ; with nearly 
 1,000 Woodcuts. 8vo. price 50s. 
 
 Weld. The Pyrenees, West and East, 
 
 a Summer Holiday in 1858. By CHAELES 
 RICHABD WELD, Barrister-at-Law. With 
 8 Illustrations in Chromo-xylography from 
 Drawings by the Author. Post 8vo. 12s. 6d. 
 
 Weld's Vacation Tour in the United States 
 and Canada, Post 8vo. with Map, 10s. 6d. 
 
 Weld's Vacations in Ireland. Post 8vo. with 
 View. 10s. 6d. 
 
 Willich's Popular Tables for ascertain- 
 ing the Value of Lifehold, Leasehold, and 
 Church Property, Renewal Fines, &c. ; the 
 Public Funds ; Annual Average Price and 
 Interest on Consols from 1731 to 1858 ; 
 Chemical, Geographical, Astronomical, Tri- 
 gonometrical Tables ; Common and Hy- 
 perbolic Logarithms ; Constants, Squares, 
 Cubes, Boots, Reciprocals ; Diameter, Cir- 
 cumference, and Area of Circles ; Length of 
 Chords and Circular Arcs ; Area and Dia- 
 
 onal of Squares ; Diameter, Solidity, and 
 uperficies of Spheres ; Bank Discounts ; 
 Bullion and Notes, 1844 to 1859. Fourth 
 Edition, enlarged. Post 8vo. price 10s. 
 
 Wilmot's Abridgment of Blackstone's 
 
 Commentaries O'^the Laws of England, in- 
 tended for the vse of Young Persons, and 
 comprised in a series of Letters from a Father 
 to his Daughter. 12mo. price 6s. 6d. 
 
 Wilson's Bryologia Britannica: Con- 
 taining the Mosses of Great Britain and 
 Ireland systematically an-angedand described 
 according to the Method of Bruch and 
 Schimper ; with 61 illustrative Plates. Being 
 a New Edition, enlarged and altered, of the 
 Muscologia Britannica of Messrs. Hooker and 
 Taylor. 8vo. 42s.; or, with, the Plates 
 coloured, price 4. 4s. cloth. 
 
 Yong. A New English-Greek Lexicon 
 
 Containing all the Greek Words used by 
 Writers of good authority. By C. D. 
 YONQE, B.A. Second Edition, revised and 
 corrected. Post 4to. price 21s. 
 
 Yonge's New Latin Gradus : Containing 
 - Every Word used by the Poets of good 
 authority. For the use of Eton, West- 
 minster, Winchester, Harrow, Charterhouse, 
 and Rugby Schools ; King's College, Lon- 
 don ; and Marlborough College. Sixth 
 Edition. Post 8vo. price 9s.; or with 
 APPENDIX of Epithets classified, 12s. 
 
 Youatt's Work on the Horse, comprising 
 
 also a Treatise on Draught. With numerous 
 Woodcut Illustrations, chiefly from Designs 
 by W. Harvey. New Edition, revised and 
 enlarged by E. N. GABBIEL, M.R.C.S., 
 C.V.S., Secretary to the Royal College of 
 Veterinary Surgeons. In One Volume, 8vo. 
 price 10s. Qd. cloth. 
 
 Youatt. - The Dog. By William Youatt. A 
 New Edition; with numerous Engravings, 
 from Designs by W. Harvey. 8vo. 6s. 
 
 Young. The Christ of History: An 
 
 Argument grounded in the Facts of His 
 Life on Earth. By JOHN YOUNG, LL.D. 
 Second Edition. Post 8vo. 7s. 6d. 
 
 Young. The Mystery; or, Evil and God. By 
 JOHN YOUNG, LL.D. Post 8vo. 7s. 6d. 
 
 Zumpt's Grammar of the Latin Lan- 
 guage. Translated and adapted for the 
 use of English Students by DB. L. SCHMITZ, 
 F.R.S.E. : With numerous Additions and 
 Corrections by the Author and Translator. 
 4th Edition, thoroughly revised. 8vo. 14s, 
 
 [September 1859. 
 
 LONDON : PRINTED BY SPOTTISWOODE & CO. NEW-STREET SQUARE 
 
TO 
 
 USE 
 
 WHICH BORROWED 
 
 LOAN DEPT. 
 
 RENEWALS ONLY TEL. NO. 642-3405 
 
 Renewed books e subject to 
 
 fARlM! 
 
 l! 
 
 LD2lA-60m-3,'70 
 (N5382slO)476-A-32 
 
 General Library . 
 University of California 
 Berkeley