rately, have been united to the Biographical Memoir, which is prefixed to this Volume. The admirable delineation of Mr PLAYFAIR'S Character, which forms the conclusion of that Memoir, is from the pen of FRANCIS JEFFREY, Esq.; and in the Appendix will be found a Letter on the same subject by Mr DUGALD STEWART. For the remainder of the Memoir, and for the execution of the whole Work, the Editor is alone responsible.

JAMES G. PLayfair.

EDINBURGH, Jan. 8, 1822.

OF

CONTENTS.

ADVERTISEMENT,

Page 17

INTRODUCTION. Object of a Theory of the Earth.

Division of minerals into Stratified and Unstratified.

SECTION Í.

p. 19

PHENOMENA PECULIAR TO STRATIFIED BODIES.

1. Materials of the Strata.

p. 22

Present strata composed of the remains of more ancient
rocks, § 1. Proofs from calcareous strata, § 2.—from
siliceous, §3.-from argillaceous, § 4.-from bitumi-
nous, § 5, 6. Absence of organized remains from the
strata called primitive, not universally true, § 8, 9.
Term Primary substituted for Primitive. Composition
from the materials of more ancient rocks, § 10.

2. Consolidation of the Strata.

P. 33

Consolidation, what, § 11. Objections to aqueous conso-

lidation, § 12, 13, 14. Compression affects the action of

fire on bodies, § 15, 16, 17. Igneous consolidation of

minerals proved from fossil wood, § 19.-from the flints

in chalk, § 20.--from sandstone, § 21.-from the cal.

VOL. I.

A

careous strata, § 23, 24, 25.-from the argillaceous, § 26,

27. from the bituminous, § 28, 29.-from the saline,

§ 32. Salt mines in Cheshire. Trona of Africa, § 34,

35.

3. Position of the Strata.

Page 56

Strata formed at the bottom of the sea, § 36. Apparent

elevation not produced by the retreat of the sea, § 37.

Strata, horizontal, when formed, § 38, 39. Disturbance

of the strata proved from their inclined position § 40, 41,

42.-from shifts, &c. § 42. Shifts of different dates, ib.

Disturbance of the primitive strata visible at their junc-

tion with the secondary, § 43, 44. This disturbance

produced by a force directed upward, § 45, 46. This

force the effect of subterraneous heat, § 47, 48.

SECTION II.

PHENOMENA PECULIAR TO UNSTRATIFIED BODIES.

1. Metallic Veins.

p. 72

Veins defined. They contain substances that were once in
fusion, § 49, 50. Metallic veins, native metals, &c. § 51.
Native copper, § 52. Manganese, § 53. Fragments of
rocks included in veins, § 55. Shifting and heaving of
veins, § 56, 57. Veins of different dates, § 58. Stratifi-
cation not found in veins. Coating of the sides, what,
$ 59. Metallic veins most common in primitive strata,
but not confined to them, § 60.