152 
MISCELLANEOUS. 
[Fart II* 
Best time for 
felling timber. 
Roots should 
not be covered 
deeply. 
fire. Nimium breves are the branches then, as 
every Christmas shows us. But all this proves 
what I began with, that all parts of plants imbibe 
in proportion as they are exposed to moisture, 
and exhaust in proportion as they are exposed 
to draught. 
I do not believe that the sap ever ceases to 
circulate; but the tide is perhaps at its lowest 
ebb in January, and that is possibly the best 
month for felling timber. Timber which is 
felled at the high tide of sap and growth is ex¬ 
tremely liable to fermentation and decay. 
It is a dangerous experiment to cover up the 
roots of trees. Their chief duty appears to be 
to absorb moisture in the soil: but atmospheric 
aeration is necessary to them; and under the 
eternal agency of physical causes, acting pro¬ 
bably on the peculiar structure of their cellular 
organisation, the roots of each tree grow at the 
level best adapted to them, and to. the offices 
which they have to perform. This should not 
be interfered with. If dressing is laid on the 
roots, it should not be deep, or of a nature im¬ 
permeable to air. 
Trees which have had their roots deeply 
covered up languish and die, unless they throw 
out a new set of roots above the old ones which 
