Tables shewing the number of free white persons, over the age of twenty years, in the several counties, cities, towns & grand divisions of the state of Virginia, who cannot read and write : the number of free white, free colored & slave titheables in the years 1830, 1840 and 1850 : the free white, free colored & slave population, distinguished, in the same years : and the amount & per cent. of increase or decrease of each class of population : and the aggregate amount of taxes assessed in the years 1840 and 1850, susbstituting, however, in 1850, the estimated tax on lots and lands in 1851, at the present rate of taxation, under the late assessment, for the actual tax of 1850 under a former assessment : together with the amoung & per cent. of increase or decrease of taxes between the periods aforesaid