Lakes have been more numerous, €&'c. 5 
this antifeptic virtue, nothing more is neceffary than 
to recollect, that water protects all bodies, covered 
by it from the injuries of the air. Ifa vegetable be 
thrown into this fluid, all its mucilage and gum will 
be foon extracted ; but the refin, the woody fibre, 
and the cellular fubftance of the pith are not foluble 
in this element. Their decompofition, therefore, 
muft entirely depend on fermentation, a procefs 
which cannot take place without a free expofure to 
the atmofphere, which communication is, in this 
cafe, precluded by the interpofition of fo unfa- 
vorable a medium. Few water plants acquire the 
properties of wood, unlefs the cany appearance of 
fome gtaffes deferves the appellation; but they in 
general contain lefs mucilage, and more pith than 
others, confequently, their texture is lefs fufceptible 
of injury from maceration. After having properly 
confidered the foregoing obfervations, fhould any 
one furvey a pond well ftored with aquatic herbage, 
the following remarks can fcarcely fail of receiving 
his approbation. 
The cavity which is, at prefent, the receptacle 
of a pool, will, in procefs of time, be occupied 
by a ftratum of folid matter, which will confift 
of the remains of ‘its own produce gradually 
accumulated and preferved by the water which 
is intimately mixed with them, and which pro- 
tedis them from decay. ‘The fubftance with 
which it is conftantly filling will acquire a com- 
pacinefs nearly uniform in eyery part, by the plants 
of 
