HO W THE ANCIENT FORESTS BECAME COAL. 61 



a book. A close examination of coal and its texture under the micro- 

 scope will show that only water could have taken all the fragments of 

 such different sizes and consistencies and arranged them in this way. 

 The disposition is the same as is always shown when leaves and frag- 

 ments of plants, having become thoroughly soaked, sink and form strati- 

 fications at the bottom of ponds. In the coal, the elements continue 

 visible, and their arrangement in superposed lamina? is evident, while 

 the interstices between the planes of junction appear to have been 

 filled up in the course of the formation of the beds. These facts, 

 with the perfect condition of the organization of many of the frag- 

 ments ; their agglomeration in an amorphous pulp, the resultant of the 

 previous maceration of a host of fragments ; and the reduction of the 

 whole mass by compression to half of its primitive thickness all 

 parts of one and the same phenomenon point to the action and weight 

 of the bed of water at the bottom of which the stratification took 

 place. The perfect uniformity which reigned over the formation of 

 coal has given it generally a schistous structure, in thin leaves dis- 

 posed in a parallel fashion and fissile in the direction of the plane of 

 deposition. It is also found, on attentive examination, to be some- 

 what varied in constituency, according to the varying character of the 

 elements of which it is composed, and the different stages of fresh- 

 ness and maturity in which they were deposited. One kind, which 

 M. Grand' Eury calls " f usaine," from its resemblance to a stick-char- 

 coal, comes from the decomposition of stems from which the anatom- 

 ical structure has disappeared while they preserve their form. The 

 green parts appear as crystalline laminae, or scales, or black particles 

 in the amorphous mass. This mass, the result of the maceration of 

 wholly decomposed particles, constitutes the amorphous coal in which, 

 besides " f usaine," we can always discover some remains of vegetable 

 structure testifying to the common origin of all the coal products. 

 Within these differences of type are innumerable variations passing 

 from one to another, the existence of which prevents our establishing 

 a clear distinction between the coals most homogeneous in appearance 

 and those which show the multifarious and manifest traces of hardly 

 altered organized elements. 



M. Grand' Eury's sketches introduce us to the depths of the carbon- 

 iferous forests, into regions of dense moisture, at the feet of gentle 

 slopes where are accumulating in stagnant ponds immense drifts of 

 the remains of constantly active, exuberant, and quickly exhausted 

 vegetation. Masses of this kind may even now be observed in the 

 midst of the virgin forests of hot countries ; how much more might 

 we have expected to find them in ancient epochs, when the trees made 

 no wood, but sent up spontaneous, ungainly shoots, sudden growths in 

 green columns, the function of which was as ephemeral as their texture 

 was weak ! Most of the carboniferous stems, hollow or filled with pith 

 only, fell by the sheer exaggeration of their growth ; the tree-ferns 



