144 



generated b^' intense pressure, yet in some cases there has been some- 

 thing approaching the state of active combustion ; probably in 

 accidental cavities of the mass into which sufficient air has penetrated 

 to support temporary combustion. 



Amongst the specimens on the table, which have been kindly lent me 

 by Mr. Daw, are some so sti'ongly resembling portions of wood, or parts 

 of plants, converted into charcoal by burning, that I will venture to 

 say, that, without a knowledge of the fact that they are true specimens 

 of coal, they would be looked upon as the results of a recent conflagi-a- 

 tion. There are other pieces which indicate a state of things different 

 from any with which we are acquainted in the ordinary processes 

 of combustion. Thus we have peculiarly lustrous layers of coal imposed 

 upon almost slaty layers, — the lustrous portion, from some cause or 

 other, breaking up into almost perfect squares. I exhibit these speci- 

 mens in the hope that some suggestions may be offered in explanation 

 of this curious result ; but I must coufess that, so far, I have been 

 unable to form any satisfactory opinion upon this question. 



That most of the coal is produced by that peculiarly slow process 

 called eremacausis, I feel convinced from the curious facts which many 

 of the specimens most clearly exliibit. 



Thus we find in masses of coal, which are apparently in no particular 

 respect different from the ordinary kinds, whole layers of small, some- 

 what lenticular bodie'S, whiclj are indubitably the vessels which have 

 contained the reproductive bodies of what was once a living plant, 

 probably, as Dr. Balfour suggests, the sporangia of sir/illarUts. How 

 does it arise that these beautifully organized sporangia which appear to 

 be unaltered in colour, and apparently only slightly flattened in form 

 by compression, are imbedded in a mass of matter which appears to 

 have been subjected to the most intense heat, a heat in most cases 

 sufficient to destroy every trace of organization ? Does it not compel 

 us to assume that the process of carbonization was materially different 

 from any similar operation with which we are acquainted, unless it be 

 that less active chymical action which the learned Liebig so effectively 

 styled eremacausis, and that these sporangia possessed means of 

 resisting this chymical action, which the rest of the material did not ? 



I assume such was the case, and am much inclined to atti'ibute their 

 preservation to the presence of some material which had a resinous 

 character, because we find very often associated with the coal in which 

 the sporangia exist, tliin lamina of a peculiar bituminous mineral called 

 middJetonite, which spreads like a brown varnish over the pieces of coal. 



The sporangia themselves, when cut open, often present an 

 appearance of this mineral in their contents. It is impossible to say 



