230 THE LIFE AND WORK OF GEORGE DON. 
This latter species grow on damp walls in crowded cities, and 
sends forth a fragrant smell. Dr. Smith thinks it may have a 
tendency to correct the bad air in such places; it colours the wall 
of a green colour, but its filaments are so fine as hardly to be seen 
with the naked eye. 
The marine plants, although many of them are extremely beauti- 
ful, are neglected or overlooked by the greater part of mankind; 
yet they most certainly are highly useful in the economy of Nature, 
although we may be ignorant of their uses. We evidently see that 
they give shelter to many of the smaller tribes of marine animals, 
and a number of others are spawned upon them, and receive from 
them their nourishment during the first stages of life. Others, 
again, seem to depend almost entirely upon them for nourishment, 
as they are attached to them through life: Such, for instance, is the 
Lepas striata, some of the genus Serpula, and some of the 
Zoophyta, as the Flustra, Sertularia, &c. The beautiful Patella 
pellucida I have often observed on the larger species of fuci; the 
animal that inhabits that shell seems to derive a great part of its 
nourishment from that tribe of vegetables. The following are 
esculent, viz. the Fucus palmatus, known by the name of dudse 
or dilse: The crispus and mamillosus are eaten among it: the F. 
pinnatifidus, known by the name of pepper-dulse : the F. esculentus, 
which is known by the name of hen-ware on the Angusshire coast: 
F. edulis, which is eaten promiscuously along with F. palmatus ; 
and the stems of the F. digitatus and F. saccharinus, which are 
sold under the name of fang or tangle. Many of the fuci are eaten 
by cattle; and the whole of them are known to make excellent 
manure. 
In some parts of Scotland, where they are extremely abundant 
on the shores, they are manufactured into kelp. The F. vesi- 
culosus, nodosus, and serratus are principally used for that 
purpose ; and on that account, Dr. Garnet, in his Tour through the 
Highlands, informs us, that in the Isle of Mull, some small farms 
which a very few years ago were let for L. 40 are, now let for L. 300 
per annum. 
The F. vesiculosus is strongly recommended by Dr. Russell in 
diseases of the glands. He says it is extremely serviceable in 
dispersing all scorbutic and scrofulous swellings. He recommends 
rubbing these with the vesicles, bruised in the hand till the mucus 
has thoroughly penetrated the parts, and afterwards washing the 
parts with sea water. He also says that scirrhosities in the 
mammee have sometimes been dispelled by this treatment. 
