CHAPTER XXXVIII.

MINERAL VEINS.

Werner's doctrine that mineral veins were fissures filled from above--Veins of segregation--Ordinary metalliferous veins or lodes--Their frequent coincidence with faults--Proofs that they originated in fissures in solid rock--Veins shifting other veins--Polishing of their walls--Shells and pebbles in lodes--Evidence of the successive enlargement and re-opening of veins--Fournet's observations in Auvergne--Dimensions of veins--Why some alternately swell out and contract--Filling of lodes by sublimation from below--Chemical and electrical action--Relative age of the precious metals--Copper and lead veins in Ireland older than Cornish tin--Lead vein in lias, Glamorganshire--Gold in Russia--Connection of hot springs and mineral veins--Concluding remarks 488

* * * * *

_Dates of the successive Editions of the "Principles" and "Elements" (or Manual) of Geology, by the Author._

Principles, 1st vol. in octavo, published in - - - Jan. 1830.

----, 2d vol. do. - - - - - - - - - - - - - - - - Jan. 1832.

----, 1st vol. 2d edition in octavo - - - - - - - 1832.

----, 2d vol. 2d edition do. - - - - - - - - - - Jan. 1833.

----, 3d vol. 1st edition do. - - - - - - - - - - May 1833.

----, New edition (called the 3d) of the whole work in 4 vols. 12mo. - - - - - - - - - - - - - - - - - - - May 1834.

----, 4th edition, 4 vols. 12mo. - - - - - - - - - June 1835.

----, 5th edition, do. do. - - - - - - - - - - - - Mar. 1837.

Elements, 1st edition in one vol. - - - - - - - - July 1838.

Principles, 6th edition, 3 vols. 12mo. - - - - - - June 1840.

Elements, 2d edition in 2 vols. 12mo. - - - - - - July 1841.

Principles, 7th edition in one vol. 8vo. - - - - - Feb. 1847.

----, 8th edition, now published in one vol. 8vo. - May 1850.

Manual of Elementary Geology (or "Elements," 3d edition), now published in one vol. 8vo. - - - - - - - - - - - - Jan. 1851.

_Works by Sir Charles Lyell._

I.

TRAVELS IN NORTH AMERICA,--1841-2. With Geological Observations on the United States, Canada, and Nova Scotia. With large coloured geological Map and Plates. 2 vols. post 8vo. 21_s._

II.

A SECOND VISIT TO THE UNITED STATES,--1845-6. _Second Edition._ 2 vols. post 8vo. 18_s._

III.

PRINCIPLES OF GEOLOGY; or the Modern Changes of the Earth and its Inhabitants considered, as illustrative of Geology. _Eighth Edition, thoroughly revised._ With Maps, Plates, and Woodcuts. 8vo. 18_s._

IV.

A MANUAL OF ELEMENTARY GEOLOGY; or the ANCIENT CHANGES of the Earth and its Inhabitants, as illustrated by Geological Monuments. Fourth Edition. _Thoroughly revised._ With 531 Woodcuts and Plates. 8vo. 12_s._

MANUAL OF ELEMENTARY GEOLOGY.