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THE..' .> ' ' ' ■ >

H I S

T O R Y

OF

F O S

S I L 8.

PART the First.

B

O O K I.

JsO S SIL S naturally and ejfentially simple, not inflammable, nor soluble in water.

Series the first.

‘Those of no regular JlruBure or determinate figure.

The Foflils of this series are comprehended in one class.

The simple earths.

Foflils are native substances found either bury d in the earth, or lying on its surface, ofa plamsimple ftru&ure, and shewing no signs of containing vessels or circulating juices.

The first class of these ; The simple earths are friable, opake, insipid bodies ; not inflam-mable, vitriflable by extream heat, diffusible in water, and separable from it by filtration.

Os these nature affords us two orders, and under those five Genera .

Order the first.

Earths naturally moist, of smooth surfaces, and a firmer texture.

Order the second.

Earths naturally dry, of rough dusty surfaces, and a looser texture.

EARTHS.

Order the first.

Genus i. Boles. Earths moderately coherent, ponderous, soft, not stiff or viscid. Butin some degree duSlile while moist, composed of fine particles, smooth to the touch, easilybreaking between the fingers, readily diffusible in wat er, and freely and easily subsidingfrom it.

Genus 2. Clays. Earths firmly coherent, weighty and compadl, very stiff and viscid,duSlile ' to a great degree while moist, smooth to the touch, not easily breaking between thefingers, nor readily diffusible in water, and when mixed in it, not readily subsiding from it.

Genus 3. Marles. Earths but slightly coherent, not duSiile, stiff or viscid whilemoist, most easily diffusible in, and disunited by water, and by it reduced into a soft, loose,mcoherent mass,

B Earths;