
          182

Dr. Kedzie says the composition of ashes of the same
plant will vary much according to the age of the plant, the
kind of soil on which it grows, and the degree of vigor of its
development.  "Perhaps it might with justice be said that the
results of chemical analysis, like those of microscopic examination,
are merely negative." p. 476.

"The most marked difference is the excess of carbonate
of potash (3.06%) and of phosphate of lime (2.55%) in the ash
of a healthy tree over that of the diseased one.  Potash is
the most characteristic element in the ash of land plants,
just as soda is in the ash of sea plants.  It is found in
large quantity in the ash of young and vigorously growing
plants, while it is deficient in those of feelber growth."
pp. 476-7.

"Soils which contain minerals in rich in potash (e.g. the
feldspars) are capable of prolonged cultivation without exhaustion;
hence the strong agricultural capabilitites of clay
soils." p. 477.

"Now this deficiency of potash in the ash of the diseased
tree, as far as it indicates anything, shows impaired 
vitality,--thus giving a chemical reason for the diminished
vigor observed in diseased trees." p. 477.
        