e on the
eastern declivity of the Cordilleras, this palm is found, constituting
forests of greater or less extent. Its smooth grey stem rising often
100 feet, forms groups that, in the northern part of Brazil, resemble
the pallisades of some gigantic fortress. The produce of these lofty
cylinders is very great, not merely of sago, which is procured only
when the process of flowering is about to occur, but many trees being
cut down before this event, a juice is obtained from them, which
forms, by fermentation, a sweet wine; while those that flower, after
which no good sago can be got, furnish an extraordinary quantity of
fruit, hanging in bunches many feet in length, which is as agreeable
as ripe apples, the taste of which it resembles. The other products of
this tree are numerous[J].

It would lead beyond just limits, were we to notice in detail, the
plants which yield starch suitable for food, only after undergoing a
process of art, by which an acrid principle is driven off, and a
bland, wholesome substance remains behind. Such is the Janipha (or
Jatropha) Manihot, which yields the Mandiocca, Tapioca, or Cassava, an
article not only of great consumption in, but also of considerable
export from, Brazil (see Spix and Martius' Travels, and Lib. of Enter.
Knowledge, Vegt. Sub. Food of Man, p. 152), which, when raw, is
poisonous both to man and cattle, though it becomes safe and agreeable
by the application of heat. So likewise the large tubers of several
_Arums_, such as _A. Macrorhizon_, _A. Colocasia_, _Caladium acre_,
and which are cultivated with great care in tropical and subtropical
countries, particularly in the Sandwich and South Sea islands. All of
these excite inflammation and swelling of the mouth and tongue, even
to the danger of suffocation, but which are disarmed of their
virulence, and converted into an article of daily consumption, by
fire. Even yams and sweet potatoes, which are naturally mild, are less
articles of consumption in the south sea islands, than the Tarro, as
these tubers of the _arums_ are designated.

I omit all other plants to fix attention on the potatoe, which is not
only the source of the purest starch of all, but has many interesting
points connected with its history and habitudes, peculiarly connected
with my subject. No plant has contributed more to banish those famines
which were formerly of so frequent occurrence in Europe, and all the
dire train of suffering and disease consequent