cover

APPENDIX B Inside back cover

LIST OF FULL-PAGE ILLUSTRATIONS

PAGE
ANTOINE LAURENT LAVOISIER _Frontispiece_

JOSEPH PRIESTLEY 14

JOHN DALTON 60

WILLIAM RAMSAY 82

DMITRI IVANOVITCH MENDELEEFF 166

HENRI MOISSAN 176

SIR HUMPHRY DAVY 276

ROBERT WILHELM BUNSEN 298

AN ELEMENTARY STUDY OF CHEMISTRY

CHAPTER I

INTRODUCTION

~The natural sciences.~ Before we advance very far in the study of nature,
it becomes evident that the one large study must be divided into a
number of more limited ones for the convenience of the investigator as
well as of the student. These more limited studies are called the
_natural sciences_.

Since the study of nature is divided in this way for mere convenience,
and not because there is any division in nature itself, it often happens
that the different sciences are very intimately related, and a thorough
knowledge of any one of them involves a considerable acquaintance with
several others. Thus the botanist must know something about animals as
well as about plants; the student of human physiology must know
something about physics as well as about the parts of the body.

~Intimate relation of chemistry and physics.~ Physics and chemistry are
two sciences related in this close way, and it is not easy to make a
precise distinction between them. In a general way it may be said that
they are both concerned with inanimate matter rather than with living,
and more particularly with the changes which such matter may be made to
undergo. These changes must be considered more closely before a
definition of the two sciences can be given.

~Physical changes.~ One class of changes is not accompanied by an
alteration in the composition of matter. When a lump of coal is broken
the pieces do not differ from the original lump save in size. A rod of
iron may be broken into pieces; it may be magnetized; it may be heated
until it glows; it may be melted. In none of these changes has the
compo