ATTENDING THE FORMATION OF COAL, &c 257 



phosfire, is due to phosphuretted hydrogen. In tropical 

 countries, favoured by the warmth, the succulent vegeta- 

 tion brought down by the large rivers into the stiller waters 

 of their estuaries, together with the abundant maritime vege- 

 tation naturally growing therein, decompose with a rapidity 

 unknown in our colder climes, and pour off their gases in 

 immense volumes, creating a pestiferous stench, and a de- 

 structive miasm, fearfully fatal to the adventurous European 

 who may visit these fetid waters. 



The production of carbonic acid and light carburetted 

 hydrogen must often be sufficiently simple ; for 2 atoms of 

 carbon uniting with the element of 2 atoms of water con- 

 taining Oa H„ would produce 1 atom carbonic acid 

 C. O5,, and 1 atom light carburetted hydrogen C. H^. 

 It will not be necessary, in the present state of geological 

 knowledge, to adduce any proofs of the vegetable origin of 

 coal and cannel. Independently of the occurrence of the 

 trunks of trees within the beds, and the abundant existence 

 of fern-like organic remains in the roofs and floors of the 

 coal scams, thin slices of coalj when examined under a 

 microscope, exhibit a true ligneous cellular structure, and 

 have all the appearance of wood. The very frequent occur- 

 rence, not only of the scattered teeth, bones, and scales 

 of fish, but of their entire skeletons, in cannel, show that 

 this latter was either formed under water, as described above, 

 or was submerged very soon after its formation. The great 

 extent to which the original structure has been destroyed in 

 cannel, also points out the subaqueous formation of it. 



The remains of fish are never found in ordinary coal, and 

 the ligneous structure is much better preserved. As the 

 accumulation of vegetable matter, by changes on the earth's 

 surface, became covered with mineral deposits, and air and 

 even water more effectually excluded from the changing 

 mass, its own substance was compelled to furnish the oxygen 

 to the hydrogen and carbon of the decaying plant, and thus 



2 L 



