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38 PATTERSON v. M'CAUSLAND.
cause of its death. So, too, the post mortem examination of a
tree can be of no value for any other purpose; except it be to find
a rule for ascertaining its age, and thereby the ages of living trees
of the same species; or to find a rule for determining the rate per
annum at which they may be expected to continue their enlarge-
ment until they reach the ultimate term of their lives.
But assuming it to be true, that the number of the concentrical
rings observed in the trunk of a tree, do always exactly corres-
pond with the number of years of its age, then at least one impor-
tant step would seem to have been made by such post mortem
examinations towards ascertaining the ages of trees in general;
as for example, if by the felling of an oak of thirty-four inches in
diameter, it should be found to have two hundred concentric lay-
ers; and, consequently, to be two hundred years old; and so to
have increased in diameter at the rate of one-twelfth part of an
inch annually; and then, assuming it to be true, that all the imme-
diately adjacent and similarly situated oaks had increased in
diameter at the same average annual rate; it follows, that the age
of every living oak in a similar soil and exposure, might from the
measurement of its circumference, be exactly ascertained by a post
mortem examination of any one, and so of every other species of
trees. Let us follow out this hypothesis, and see to what it will
lead.
It has been found, that a larch tree, in England, will, under
favourable circumstances, increase, until fifty years of age, at the
rate of half an inch annually in diameter; and that some elms,
planted in France in the year 1580, if what is said of their circum-
ference be correct, had increased at the same rate in diameter until
two hundred and forty years of age. (t) But it has been observed,
that the latter concentrical layers of wood in an oak of no more
than two hundred years of age, were so much thinner than those
of its youth, as to be scarcely distinguishable; and that other
kinds of trees, known to be of rapid growth in early life, have
been found, by actual measurement, after they had attained a con-
siderable age, to have remained nearly of the same circumference
during the lapse of twenty years, (u) Therefore, after allowing
(t) i Mich. Am. Sylva, 225. (Several elm trees, said to have been planted in the
public green at Hew Haven, in Connecticut, in the year 1688, were standing in the
year 1838, and then measured about fourteen feet in circumference; which gives an
increase of diameter at the rate of about the half of an inch annually.'—The Globe
newspaper, published at Washington, 21st September, 1838.
(u) 1 Mich. Am, Sylva, 324.
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