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 the lower British North American Provinces.  It is known under the native name of Saa-ga-ban by the Micmac Indians, by whom the pear-shaped roots are used as an article of food.  Like the Arachis hypogaea, it belongs to the Leguminosae family.  The fruit and flower resemble those of the wood vetch.  It is thus described in Professor Eaton’s “Manual of Botany for North America,” published in 1836:—­“Color of corolla, blue and purple; time of flowering, July (and August in Nova Scotia), perennial; stem, twining; leaves, pinnate, with seven lance-ovate leaflets; racemes shorter than the leaves, axillary; root, tuberous.  Root very nutritive; ought to be generally cultivated.”