Science Books

PREFACE. The present volume consists of essays which I have contributed to various periodicals, or read before scientific societies during the last fifteen years, with others now printed for the first time. The two first of the series are printed without alteration, because, having gained me the reputation of being an independent originator of the theory of “natural selection,” they may be... more...

There are three ways of regarding any account of past occurrences, whether delivered to us orally or recorded in writing. The narrative may be exactly true. That is to say, the words, taken in their natural sense, and interpreted according to the rules of grammar, may convey to the mind of the hearer, or of the reader an idea precisely correspondent with one which would have remained in the mind of a... more...

PREFACE In offering this book to teachers of elementary chemistry the authors lay no claim to any great originality. It has been their aim to prepare a text-book constructed along lines which have become recognized as best suited to an elementary treatment of the subject. At the same time they have made a consistent effort to make the text clear in outline, simple in style and language, conservatively... more...

CHAPTER I ON RAYS PROPAGATED IN STRAIGHT LINES s happens in all the sciences in which Geometry is applied to matter, the demonstrations concerning Optics are founded on truths drawn from experience. Such are that the rays of light are propagated in straight lines; that the angles of reflexion and of incidence are equal; and that in refraction the ray is bent according to the law of sines, now so well... more...

CHAPTER I. APPARENT ATTRIBUTES OF THE STARS. 1. Our knowledge of the stars is based on their apparent attributes, obtained from the astronomical observations. The object of astronomy is to deduce herefrom the real or absolute attributes of the stars, which are their position in space, their movement, and their physical nature. The apparent attributes of the stars are studied by the aid of their... more...

CHAPTER I THE AIMS OF NATURE STUDY Nature Study means primarily the study of natural things and preferably of living things. Like all other subjects, it must justify its position on the school curriculum by proving its power to equip the pupil for the responsibilities of citizenship. That citizen is best prepared for life who lives in most sympathetic and intelligent relation to his environment, and it... more...

THE CAT. PART 1.walk´-ingthoughtknewsheathswatchedstrokedsmoothwon´-dergroundfore´-pawsyawnmis-take´shak´-ingtoesstretchedclaw1. Pussy came walking along the garden-path. Harry watched her, and saw that she did not like the damp ground. 2. She jumped over the pools, and then began to run, shaking her paws as she got to the house. 3. 'Now, a dog does not mind wet feet,' Harry thought;... more...

PREFACE Tins volume contains twelve essays written at various timesduring recent years. Many of them are studies contributed toScientific Reviews or delivered as popular lectures. Some areexpositions of views the scientific basis of which may beregarded as established. Others—the greater number—may bedescribed as attempting the solution of problems which cannot beapproached by direct observation.... 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... more...

How does it come about that alongside of the idea of ponderable matter, which is derived by abstraction from everyday life, the physicists set the idea of the existence of another kind of matter, the ether? The explanation is probably to be sought in those phenomena which have given rise to the theory of action at a distance, and in the properties of light which have led to the undulatory theory. Let... more...