es of Madeira, namely,
Tinto, Verdelho, Gual, Listan, Malvasia,[5] &c., but they are not equal
in quality to the fine wines of the south side, yet superior to the
wines of the north side, of that island. They are distinguished by what
may be called the generic denominations of dry and sweet. The dry is
well known by the name of Vidonia, and the sweet as Malvasia. The first
quality of the former can only be obtained from the most respectable
merchants, it being a very common process to convert it, by admixtures,
into a counterfeit of Madeira, or sherry, and occasionally to drug it
with port. The strongest quality of the celebrated wine called sack,[6]
is made in Teneriffe, Grand Canary, and Palma.

Carbonate of soda is obtained from the _sal sola soda_, extensively
cultivated at Lanccrota and Forteventura. It is gathered in September,
dried, and then charred or fused into a ringing, hard, cellular mass,
of a greyish blue colour. A small quantity is made also at Grand
Canary. The barilla of the Canary Islands has been sold in England so
high as 80l. a ton, and as low as 6l.; at the present time, (December,
1833) it is worth 9l. 10s. a ton. The depreciation is caused chiefly by
kelp, and other substitutes found in the British alkali, a French
chemical discovery, manufactured from sea salt, from which, the other
ingredients are detached, by combination with sulphur, and acids
subjected to heat. The imports of barilla from the Canary Islands to
this country are about 3,500 tons a-year. The United States of America,
and of late years, Brazil, also, take off a few cargoes of this
article. Lancerota produces, annually, about 300 tons of barilla; Forte
ventura about 1500 tons.

Rock moss (Parmelia perlata) is worth about 70l. a ton, and is one of
the innumerable lichens common to the Canary Islands; it is used in the
manufacture of cudbear for the dyers. There is also a spurious kind,
with difficulty distinguished from the good.

Silk is chiefly produced at Palma. There is but little exported from
Teneriffe. It might, however, be produced in immense quantities, the
white and red mulberry tree being indigenous and luxuriant in the
middle region of the island, and the climate so mild, that the insect
could be hatched and reared under wooden sheds, without any difficulty.
The great defect in the Teneriffe silk is the coarseness of the fibre,
from want of dexterity in winding it off the cocoons, and in regulating
the heat to whic