Ee Pe ee IS 
Lakes have been more numerous, -&c. 7 
we leave fpeculation to compare the theory with what 
has paffed in the world, we fhall find every reafon 
to believe, that the plan fuggefted by reflexion has 
been employed by nature in performing the oufinefs 
in queftion: For, it is upon this Principle alone, 
that we can account for the produétion of thofe flat 
marfhes that fupply many countries in the north of 
Europe with fuel. Several circumftances concur 
to demonftrate, that thefe fwamps are indebted for 
their prefent appearance to the procefs defcribed 
above; and perhaps it will not be improper to 
mention a number of faéts in this place, that feem 
well calculated to eftablifh the opinion. Could we 
remove from one of them all the peculiar foil 
whereby it is diftinguifhed from the furrounding 
Jand, the cavity left after the operation would foon 
be converted into a lake; for in every bog there is 
a quantity of water always ready to occupy any 
depreffion that will anfwer the puipofe of a refer- 
voir. And, in fact, humidity is fo neceffary to the 
prefervation of this kind of earth, that when it is 
expofed to the air it lofes its diftinguilhing properties, 
and is changed into mold. Theve is another cir- 
cumfiance in which the woiks of Nature correfpond 
accurately with the theory ; for, in feveral marthes, 
very deep ponds are fill to be met with. In fome 
places they are open, and prefent themfelves to 
the fight; but in others, they are dangerous pits, 
which are more or lefs concealed by a thin cruft 
formed by aquatic plants, that float on the furface 
) of 
