CHAPTER I. IS THE BODY A MACHINE? The problem before us in this section is to find out to what extent animals and plants are machines. We wish to determine whether the laws and forces which regulate their activities are the same as the laws and forces with which we experiment in the chemical and physical laboratory, and whether the principles of mechanics and the doctrine of the conservation of energy apply equally well in the living machine... more...

CHAPTER I. THE ASTRONOMICAL OBSERVATORY. Early Astronomical Observations—The Observatory of Tycho Brahe—The Pupil of the Eye—Vision of Faint Objects—The Telescope—The Object-Glass—Advantages of Large Telescopes—The Equatorial—The Observatory—The Power of a Telescope—Reflecting Telescopes—Lord Rosse's Great Reflector at Parsonstown—How the mighty Telescope is... more...

CHAPTER I. BACTERIA AS PLANTS. During the last fifteen years the subject of bacteriology [Footnote: The term microbe is simply a word which has been coined to include all of the microscopic plants commonly included under the terms bacteria and yeasts.] has developed with a marvellous rapidity. At the beginning of the ninth decade of the century bacteria were scarcely heard of outside of scientific circles, and very little was known about them... more...

CHAPTER I. THE DISCOVERY OF THE UNIVERSE The beginning of the victorious career of modern science was very largely due to the making of two stimulating discoveries at the close of the Middle Ages. One was the discovery of the earth: the other the discovery of the universe. Men were confined, like molluscs in their shells, by a belief that they occupied the centre of a comparatively small disk—some ventured to say a globe—which was... more...

THE SCIENTIFIC EVIDENCES OF ORGANIC EVOLUTION. Although it is generally recognised that the Origin of Species has produced an effect both on the science and the philosophy of our age which is without a parallel in the history of thought, admirers of Mr. Darwin's genius are frequently surprised at the ignorance of his work which is displayed by many persons who can scarcely be said to belong to the uncultured classes. The reason of this ignorance... more...

INTRODUCTORYTo the following Treatise. O give the Reader an account, Why the following Treatise is suffer’d to pass abroad so maim’d and imperfect, I must inform him that ’tis now long since, that to gratify an ingenious Gentleman, I set down some of the Reasons that kept me from fully acquiescing either in the Peripatetical, or in the Chymical Doctrine, of the Material Principles of mixt Bodies. This Discourse some years... more...

That application of the sciences of biology and geology, which is commonly known as palaeontology, took its origin in the mind of the first person who, finding something like a shell, or a bone, naturally imbedded in gravel or rock, indulged in speculations upon the nature of this thing which he had dug out—this "fossil"—and upon the causes which had brought it into such a position. In this rudimentary form, a high antiquity may... more...

THE PRESENT CONDITION OF ORGANIC NATURE. When it was my duty to consider what subject I would select for the six lectures [*To Working Men, at the Museum of Practical Geology, 1863.] which I shall now have the pleasure of delivering to you, it occurred to me that I could not do better than endeavour to put before you in a true light, or in what I might perhaps with more modesty call, that which I conceive myself to be the true light, the... more...

All knowledge is essentially one. The object-matter upon which intellect exerts itself, does not affect the subjective act of knowing. Physics, when stripped of that which is merely contingent, becomes metaphysics. Physical science deals with object-matter, and discusses the signs by which nature communicates her message—that is, phenomena. Metaphysical science has to do with the subject-mind, and discusses the meaning of the message. The... more...

The inquiry which we undertook, at our last meeting, into the state of our knowledge of the causes of the phenomena of organic nature,—of the past and of the present,—resolved itself into two subsidiary inquiries: the first was, whether we know anything, either historically or experimentally, of the mode of origin of living beings; the second subsidiary inquiry was, whether, granting the origin, we know anything about the perpetuation... more...