PROPERTIES AND USES. 391 
In this and other countries the fronds are cut and dried, 
and used for many domestic purposes, such as thatching, 
and for protecting vegetables and tender plants from frost, 
and the young fronds are given to swine. The fronds are 
burned in large heaps, and the ashes contain a considerable 
quantity of alkali, which is made into cakes or balls, which 
form an article of trade, especially in Wales, and are used 
as soap in washing, it is also used by glass makers. The 
whole plant contains a considerable amount of tannic and 
gallic acids, and its astringency is such that in some 
countries it is used for tanning leather. 
Many medical properties have been ascribed to it, but 
with the exception of being used as a vermifuge its many 
extolled virtues are now obsolete. 
It is, however, an important food fern, its creeping 
underground stems contain a quantity of starch and muci- 
lage, and are used in some parts of Europe and other 
northern countries for mixing with meal to make bread ; 
even in the Canary Islands, especially those of Palma and 
Gomera, where food is often scarce, it is mixed with barley ` 
. meal and made into a kind of gruel. Of late years it has 
~ been brought into notice as a substitute for better food in 
this country. The Rev. M. J. Berkeley, in an article in 
the Journal of the Linnman Society, says the roasted roots 
are eatable, but extremely disagreeable from their slimy 
.. mature and peculiar flavour, in both of which they resemble 
— illripened Bringles, but by cutting up and soaking them 
in water the slimy matter and astringent principle is got 
. rid of, and the pulp, when sufficiently dry and made into 
cakes, forms a coarse but palatable food. 
_ In 1857 it was again brought into notice by Mr. ihe 
jamin Clark, who, in an article in Hooker’s “Journal of ` 
mar described its qualities as a vegetable, but in this ` 
