PART YI. CHAPTER I. MARBLE. Komiger Kalk, Marmor (Germ.) Calcaire saccharoide, Marbre (Fr.) Spec, grav., 2.6-2.8. The true marbles are crystalline limestones capable of receiving a polish. They are exceedingly various in colour, pattern, and structure, owing to the inter mixture of foreign or accidental substances, and their mode of formation. They also vary much in hardness and durability, and in the degree of crystallization. Marbles under some form are found amongst all great limestone formations. It would, therefore, be impossible to describe them in any degree of detail; and I must content myself with some account of the more valuable kinds in use in ancient and modern times, both in this country and the Continent. These we shall discuss under the two general heads of ornamental and statuary marble. These rocks are amongst the most beautiful pro-