Is it, then, necessary for chemists to understand the relative nature of all substances?

Yes; because the basis of this science consists in an analytical examination of the works of Nature; an investigation of the properties and uses of all substances we are acquainted with; and the study of the effects of heat and mixture, in order that we may find out their general and subordinate laws.

     Analytical, relating to analysis.

     Investigation, act of searching, or tracing out.

     Subordinate, inferior in nature, dignity or power.

Relate a few more of the advantages obtained by a knowledge of Chemistry.

Many of the wonderful operations of Nature, and the changes which take place in substances around us, are, by its means, revealed to us.  In every manufacture, art, or walk of life, the chemist possesses an advantage over his unskilled neighbor.  It is necessary to the farmer and gardener, as it explains the growth of plants, the use of manures, and their proper application:  and indispensable to the physician, that he may understand the animal economy, and the effects which certain causes chemically produce; and the nature of animal, vegetable, and mineral poisons.  The study is, therefore, an invaluable branch in the education of youth:  it is useful, not only in the active, but the moral life, by laying the foundation of an ardent and inquiring mind.  Even an everyday walk in the fields can be productive of instruction, by a knowledge of it;—­and let us always remember, that “Knowledge is Power.”

     Indispensable, necessary, not to be done without.

CHAPTER XIX.

ATTRACTION, TIDES, GRAVITY, ARTESIAN WELLS, AIR, ANEROID
BAROMETER, EAR-TRUMPET, STETHOSCOPE, AUDIPHONE, TELEPHONE, PHONOGRAPH,
MICROPHONE, MEGAPHONE, TASIMETER, BATHOMETER, ANEMOMETER,
CHRONOMETER.

What is Attraction?

By attraction is meant that property or quality in the particles of bodies which makes them tend toward each other.

Are there several kinds of attraction?

Yes.  Attraction has received different names, according to the circumstances under which it acts:  The force which keeps the particles of matter together to form bodies or masses, is called attraction of cohesion; that which makes bodies stick together only on their surfaces, is called adhesion; that which inclines different masses toward each other, as the earth and the heavenly bodies, is called gravitation; that which forces the particles of substances of different kinds to unite, is known under the name of chemical attraction; that which causes the needle of the compass to point constantly toward the poles of the earth, is magnetic attraction; that which is excited by friction in certain substances, is known as electrical attraction.