INTRODUCTION

TO

THE STUDY OF MINERALOGY.

CHAPTER I.

DEFINITIONS AND PRELIMINARY OBSERVATIONS.

1. The extensive field and the numerous objects, which Natural History presents for our observation, render systematic arrangementand division of labor absolutely necessary. By these means each in-dividual is enabled to direct his attention to some particular class ofbodies, with advantage to himself and the public ; and to pursue hisfavorite path in natural science without that confusion and perplexity,which the multiplicity of objects would otherwise produce.

2. Natural bodies may with great propriety be divided into twoextensive classes; organic and inorganic.

3. Organic bodies have a peculiar structure, which consists in thepossession of certain organs, on the proper action of which they de-pend for increase and perfection. This class embraces animals andvegetables; the former of which is distinguished from the latter bypossessing the power of voluntary motion.

4. Inorganic bodies, on the contrary, possess neither life, nor thepower of voluntary motion; they are entirely destitute of organicstructure, and suffer change from the influence of external agents on-ly. In this class we find minerals, and adopt the following definition.

5. Minerals are those bodies, which are destitute of organization,and which naturally exist within the earth, or at its surface.*

6. Mineralogy is that science, ■which has for its object a knowl-edge of the properties and relations of minerals, and enables us todistinguish, arrange, and describe them.

7. The writers of the Wernerian school usually divide mineralogyinto the following five branches.

* The tenn fossil is usually appropriated to those organic substances, whichhave become penetrated by earthy or metallic particles; thus we say fossilshells, fossil bones, fossil wood, &c. Sometimes however the alteration, whichthese bodies have undergone in the mineral kingdom, is very slight. But theconsideration of fossils belongs more particularly to geologv.

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