Chapter I.--Prelude to the Epoch of De Lisle and Haüy. 316

CHAPTER II.--EPOCH OF ROMÉ DE LISLE AND HAÜY.--ESTABLISHMENT OF THE FIXITY OF CRYSTALLINE ANGLES, AND THE SIMPLICITY OF THE LAWS OF DERIVATION. 320

CHAPTER III.--RECEPTION AND CORRECTIONS OF THE HAUÏAN CRYSTALLOGRAPHY. 324 {14}

CHAPTER IV.--ESTABLISHMENT OF THE DISTINCTION OF SYSTEMS OF CRYSTALLIZATION.--WEISS AND MOHS. 326

CHAPTER V.--RECEPTION AND CONFIRMATION OF THE DISTINCTION OF SYSTEMS OF CRYSTALLIZATION.

Diffusion of the Distinction of Systems. 330 Confirmation of the Distinction of Systems by the Optical Properties of Minerals.--Brewster. 331