Considerable light has recently been
thrown upon the subject by a well known chemist. It is asserted that
living cells containing a saccharine liquid do not permit infiltration
from interior to exterior; this phenomenon occurs only when cell and
tissue are dead. It is necessary that the degree of cold should be
sufficiently intense, or that a thaw take place, under certain
conditions, to kill tissue of walls of said cells. An interesting fact
is that when cells are broken through the action of freezing, it is
not those containing sugar that are the first affected. The outer
cells containing very little sugar are the first to expand when
frozen, which expansion opens the central cells.
Experiments to determine the action of lime upon soils apparently
prove that it does not matter in what form calcic salts are employed;
their effect, in all cases, is to increase the yield of roots to the
acre. On the other hand, very secondary results were obtained with
phosphoric and sulphuric acids.
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