y a ton of starch--equal, at
9d. per lb., to L84.

The experimental researches of Dr. Shier have led him to believe that
the green bitter cassava will give one-fifth its weight of starch. If
this be the case the return per acre would, under favorable
circumstances, when the land is properly worked, be enormous. On an
estate at Essequibo, a short time ago, an acre of cassava, grown in
fine permeable soil, was lifted and weighed; it yielded 25 tons of
green cassava. Such a return as this per acre would enable our West
India colonies to inundate Great Britain with food, and at a rate
which would make flour to be considered a luxury. Dr. Shier is
convinced that, in thorough drained land, where the roots could
penetrate the soil, and where its permeability would permit of their
indefinite expansion, a return of 25 tons an acre might uniformly be
calculated upon. What a blessing, not only for those colonies, but for
the world, would the introduction be of this cheap and nutritious
substitute for the potato.

NEW TUBEROUS PLANTS RECOMMENDED AS SUBSTITUTES FOR THE POTATO.

In the present disturbed state of the grain markets of Europe, the
advantage of cultivating plants which directly or indirectly can form
a substitute for the potato, admits of no doubt. It appears to me,
moreover, that when the way is once opened up, even under ordinary
circumstances, the tropical colonies of Great Britain, without
diminishing the quantity of sugar and coffee they produce, could
advantageously supply the British market with the purest starches, and
possibly also with various other articles of farinaceous food.
Anything that will lead the planters to a more varied cultivation than
the present uniform and persistent one, will be advantageous to our
colonies; and the growth of farinaceous root crops for exportation,
cannot fail to produce most beneficial effects on that class of the
peasantry in the British possessions, who are owners of small lots of
land, which at present they either totally neglect, or cultivate most
imperfectly.

In 1846, Dr. A. Gesner, one of my correspondents, called attention, in
my "Colonial Magazine," to two indigenous roots of North America,
which he thought deserving special attention. These were _Apios
tuberosa_, and _Claytonia acutiflora_, _or Virginiana_.

1. _A. tuberosa_ (Boerhave), or _Glycine Apios_.--This plant is common
throughout the Northern and Southern States of America, and is also
met with in t