Fig. 1. Granite. 2. Gneiss. 3. Mica─slate. 4. Clay─slate. a. Lime─stone. b. Quartz. 5. Primitive lime─stone. II. Secondary Rocks. 1. Transition Rocks. 6. Grey─wacka. 7. Transition lime─stone. 2. Floetz Rocks. 8. Old red sand─stone. 9. Alternating strata of lime─stone and sand─stone. III. Alluvial Deposits. 10. Alluvial strata of clay, gravel, &c., &c. ─────── The BINDER is desired to insert all the Plates, except the Frontispieces, immediately after the Explanations in the respective Volumes. ──────────────────────────────────────────────────────────────────────── [Illustration: Pl. 1. Vol. I. Sections of Strata &c. J. Shury. sculp.] [Illustration: Pl. 2. Vol. I. CRYSTALS &c.] [Illustration: Pl. 3. Vol. I. Section of Rocks. J Shury sculp.] ──────────────────────────────────────────────────────────────────────── USEFUL KNOWLEDGE. ─────── MINERALS. ─────── _INTRODUCTION._ 1. MINERALS are natural bodies destitute of organization and life: and MINERALOGY is that branch of natural science which treats of the properties and relations of such bodies. MINERAL DEPOSITS. 2. If we penetrate beneath the surface of the earth, we observe there a very remarkable arrangement. Instead of a generally uniform appearance, as we see on the surface, we pass through divers substances, as clay, gravel, sand, and numerous others, deposited in _beds_ or _strata_ of various thickness, from a few inches to a great many feet (Pl. I. Fig. 1). These lie, for the most part, nearly horizontal: but in some instances, particularly in mountainous countries, they take different degrees of inclination; and, in places where the country consists of gently sloping hills and vales, the beds have a waving or bending form (Pl. 1, Fig. 3). The strata of which the earth is composed, as deep as the curiosity or the necessities of mankind have induced them to explore, satisfactorily demonstrate the wisdom which has been displayed in the arrangement of materials requisite for the use of men and animals.