One of many such may be cited in the Star vein at Cherry Creek, Nevada, which, nearly at right angles to their strike, cuts belts of quartzite, limestone, and slate, maintaining its peculiar character of ore and gangue throughout.

Where these occur, the same sheet of rock may contain several systems of veins with different ores and gangues.

4. Gangue, or waste rock, thrown on the dump heaps.

The surface of the isolated specimens is well defined, and their separation from the gangue (which has never been penetrated) is of the easiest character.

These fragments sometimes exhibit a fracture analogous to that of ordinary coal, with sharp angles that show that they have not been rolled; and the sandstone has taken their exact details, which are found in hollow form in the gangue.

These pebbles of coal have not been misshapen under the pressure of the surrounding sandstone, nor have they shrunk since their burial and the solidification of the gangue, for their surface is in contact with the internal surface of their matrix.

Thanks to the kindness of Mr. Fayol, we have been enabled to make such researches upon numerous specimens that were still inclosed in their sandstone gangue and that had been collected in the coal strata of Commentry.

The elementary chemical composition, which is perceptibly the same in the specimens isolated in the sandstones and in those taken from the great deposit, demonstrates that the difference in composition of the environment serving as gangue did not have a great influence upon the definitive state of the coal, a conclusion that we had already reached upon examining the structure and properties of the coal pebbles.

In the midst of a mass of blackish debris, a, organic and inorganic, and immersed in an amorphous and transparent gangue, we find a few recognizable fragments, such as thick-walled macrospores, b, of various sizes, bits of flattened petioles, c, pollen grains, d, debris of bark, etc.

Cannel coal, then, shows that it is formed of a sort of dark brown gangue of resinoid aspect (when a thin section of it is examined) holding in suspension indeterminable black organic and inorganic debris, which are arranged in layers, and in the midst of which (according to the locality and the fragment studied) is found a varying number of easily recognized vegetable organs.

Ce sont des galets calcaires, agreges dans une terre sablonneuse ocracee, qui leur est tellement adherente, qu'on ne sauroit detruire cette espece de gangue sans les briser eux memes.

" "Bud, 'Sieur Frowenfel', I am afred to paz dad gangue!