258 WILLIAMS' CASE.—3 BLAND.

477; Saville v. Saville, 2 Atk. 463; Penrhyn v. Hughes, 5 Ves. 107;
Powel Mortg. 921, note H. This rule compelling a tenant for life
to discharge the interest of mortgages ami other real incum-
brances, applies as well to tenants for years; Amesbury v. Brown, 1
Ves. 480; to tenant in dower, and a tenant by the curtesy, a,s to
all other kinds of tenants for life: Petersborough v. Mordaunt, 1
Eden, 478; Tracy v. Hereford, 2 Bro. C. C. 128; Shrewsbury v.
Shrewsbury, 3 Bro. C. C. 126; 8. C. 1 Vex. Jun., 227; Bertie v.
Abingdon, 3 Meriv. 500: Burgess v. Mawbey, 31 Cowd. Cha. Rep. 96;
except, that as to the dowress, she, being entitled bnt to one-third
of the estate during her life, will not be compelled to keep down
more than one-third of the interest of any charges affecting the
real estate in which she is entitled to dower; Banks v. Sutton, 2 P.
Will. 716; and as to her share of the principal, supposing that in
order to be let into her dower she is obliged to redeem the whole
mortgage, it is conceived, that she would have a claim on the
estate for two-thirds of the interest, and the whole of the princi-
pal. Palmes v. Danby, Prec. Chan. 137; Powel Mort. 923, note; 1
Mad. Chan. 238.

* I am not aware that any observations have been made
246 any where in the United States, as to the average rate of
mortality, from which a table of the expectation of human life at
the various ages could be formed; except those before mentioned
of the City of Philadelphia. A sensible writer has, however, inti-
mated, that he had, for some years, been endeavoring to collect
data upon which to found a calculation of the average duration of
life in the Southern Atlantic States, comprising Georgia, the Caro-
linas, and Virginia. 2 Southern Review, 175. But as it would
seem the only materials which have, as yet, been collected which
would be likely to afford any aid in the formation of such a table,
are the few and imperfect bills of mortality which have been kept
in some of the cities; Seybert Stat. Ann. 49; the reports of the sur-
geons of the army as to the health of the troops at the places
where detachments of them have been stationed, the pension list,
and the census of the Union.

The Roman census was a numbering of the people with a valua-
tion of their fortunes; which, although said to have been made
every five years, was not always taken at certain intervals; and
was sometimes omitted altogether. It does not, however, appear
to have been, in fact, an enumeration of all the inhabitants, but
was merely a numbering and classing of the citizens of Rome, and
of the colonial cities; Adams' Rom. Ant. 89,134; and, being com-
mensurate with property, power, and taxation, seems to have
been, in many respects, more like what, in Maryland, is called an
assessment law for the valuation of real and personal property for
the purpose of taxing it, than such a census as is directed to be
taken by the Constitution of the United States. Gibbon's Decl.