i88oJ 
The Formation of Coal . 
85 
duced the lower pulp ; but these coming into the water at 
the period of its turbidity and of the rapid deposition of mineral 
matter, would be sealed up one by one as the mineral parti- 
cles surrounding it subdivided. Fossils of estuarine animals 
would of course accompany these, or of fresh-water animals 
where, instead of a fjord, the scene of these proceedings is 
an inland lake. In reference to this I may state that at the 
inner extremities of the larger Norwegian fjords the salinity 
of the water is so slight that it is imperceptible to taste. I 
have freely quenched my thirst with the water of the Sor- 
fjord, the great inner branch of the Hardanger, where pallid 
specimens of bladder wrack were growing on its banks. 
In the foregoing matter-of-fadt picture of what is pro- 
ceeding on a small scale in the Aachensee, and on a larger 
in Norway, we have, I think, a natural history of the forma- 
tion not only of coal seams, but also of the coal measures 
around and above them. The theory which attributed our 
coal seams to such vegetable accumulations as the rafts of 
the Mississippi is now generally abandoned, mainly because 
it fails to account for the state of preservation and the posi- 
tion of many of the vegetable remains associated with coal, 
which show no signs of river transport. 
There is another serious objedtion to this theory that I 
have not seen expressed. It is this Rivers bringing down 
to their mouths such vegetable deltas as are supposed, 
would also bring considerable quantities of earthy matter in 
suspension, and this would be deposited with the trees. 
Instead of the 2 or 3 per cent of incombustible ash com- 
monly found in coal we should thus have a quantity more 
nearly like that found in bituminous shales, viz., from 20 to 
80 per cent. 
The alternative hypothesis now more commonly accepted 
—that the vegetation of our coal-fields adtually grew where 
we find it— is also refuted by the composition of coal-ash. 
If the coal consisted simply of the vegetable matter of buried 
forests its composition should correspond to that of the 
ashes of plants ; and if so the refuse from our furnaces and 
fireplaces would be a most valuable manure. This we know 
is not the case. Ordinary coal-ash, as Bischof has shown, 
nearly corresponds to that of the rocks with which it is 
associated ; and he says that “ the conversion of vegetable 
substances into coal has been effected by the agency of 
water;” and also that coal has been formed, not from 
dwarfish mosses, sedges, and other plants which now con- 
tribute to the growth of our peat bogs, but from the stems 
and trunks of the forest trees of the Carboniferous Period, 
