Another very curious substance is found with the lignite--yellow amber. It is the mineralised resin, which flowed from certain extinct pine-trees of the Tertiary epoch; the waves of the Baltic Sea, washing the amber out of the deposits of sand and clay in which it lies buried, this substance, being very little heavier than water, is thrown by the waves upon the shore. For ages the Baltic coast has supplied commerce with amber. The Phœnicians ascended its banks to collect this beautiful fossil resin, which is now chiefly found between Dantzic and Memel, where it is a government monopoly in the hands of contractors, who are protected by a law making it theft to gather or conceal it. Amber,[91] while it has lost none of its former commercial value, is, besides, of much palæontological interest; fossil insects, and other extraneous bodies, are often found enclosed in the nodules, where they have been preserved in all their original colouring and integrity of form. As the poet says-- [91] See Bristow’s “Glossary of Mineralogy,” p. 11. “The things themselves are neither rich nor rare, The wonder’s how the devil they got there.” The natural aromatic qualities of the amber combined with exclusion of air, &c., have embalmed them, and thus transmitted to our times the smaller beings and the most delicate organisms of earlier ages. The Miocene rocks, of marine origin, are very imperfectly represented in the Paris basin, and their composition changes with the localities. They are divided into two groups of beds: 1. _Molasse_, or soft clay; 2. _Faluns_, or shelly marl. In the Paris basin the _Molasse_ presents, at its base, quartzose sands of great thickness, sometimes pure, sometimes a little argillaceous or micaceous. They include beds of sandstone (with some limestone), which are worked in the quarries of Fontainebleau, d’Orsay, and Montmorency, for paving-stone for the streets of Paris and the neighbouring towns. This last formation is altogether marine. To these sands and sandstones succeeds a fresh-water deposit, formed of a whitish and partly siliceous limestone, which forms the ground of the plateau of La Beauce, between the valleys of the Seine and the Loire: this is called the _Calcaire de la Beauce_. It is there mixed with a reddish and more or less sandy clay, containing small blocks of burrh-stone used for millstones, easily recognised by their yellow-ochreous colour, and the numerous cavities or hollows with which their texture is honeycombed. This grit, or _silex meulier_, is much used in Paris for the arches of cellars, underground conduits, sewers, &c.