A BOTANICAL TOUR THROUGH SOUTH WALESj &C. 
297 
frond convex, hemispherical, lessening in thickness from the centre to the cir¬ 
cumference. Frond exceeding two inches in diameter, skin thick and slightly 
rugose, substance beneath of the same dark olive-green hue, jelly-like, and semi¬ 
transparent. Unattached upon the limestone slabs near the water, but not im¬ 
mersed in it. I brought a specimen home with me wrapt in leaves, and placing 
it in water preserved it for three weeks, but no hue was imparted to the water 
in which it was kept. It finally dried up, preserving its outline on a sheet of 
paper, to which I transferred it. This curious plant somewhat resembles, though 
evidently distinct from, Palmella montana (Ulvamontj Eng. Bot.^ 2193), which 
Lightfoot mentions as used by the Highlanders, who wash it, rub it between 
their hands in water, and make a paste with it, with which they purge their 
calves* In form it approaches the largest figure of Rwidaria calcarea in Eng. 
t. 1799, which Sir J. E. Smith calls a “singular production,” reported by 
several friends to have been found “ about many water falls in North and South 
Wales, Shropshire, &c.” Smith describes this plant as belonging to a genus 
“ destitute of an external cuticle,” which the plant I found evidently has. He 
also describes his R. calcarm as having sessile fronds,^ “ round, generally clus¬ 
tered or aggregate, each as big as a pea, or larger, but often united into an 
uneven undeterminate mass. The external surface is of a rich dark green.” My 
Palmella, on the contriry, is of a dark glue colour, not aggregated, oval, or he¬ 
mispherical, and more than two inches in diameter. The Rivularia is also stated 
to be “ impregnated with a calcareous sediment, which renders it hard, though 
friable,” while certainly there was no trace of any stalagmitic particles in my 
plant, which I believe to have been before unnoticed. 
Passing from the cavern to Curn Forth Farm, to obtain a draught of milk, I 
noticed a singular old Elder-tree (Sambucus nigra), of larger dimensions than 
any that ever previously came under my inspection. It had quite a venerable 
t&spect,' hoary with Lichens, bearded with Polypody, and entirely hollow. Its 
girth at the base was 14 feet, and 8 feet at two yards from the ground. I have 
before hinted at the probability of the introduction of this tree into Britain by 
the Romans, who long made South Wales a favourite seat of their arts and arms ; 
and this singular old relic in the neighbourhood of an ancient Nidum, and not far 
removed from a Roman way over the mountains, is in favour of my idea ; the 
virtues and fame of the Elder having travelled hither from Greece, and been 
acknowledged by learned compounders in all ages. Hence, even so late as 
Evelyn's time, he has not scrupled in his Sglva to enlarge upon the “ uses of 
the Elder, either for sickness or wound.” “ The inner bark,” he says, “ applied 
to any burning, takes out the fire immediately; that, or, in season, the buds, 
boiled in water-gi’uel for a breakfast, has effected wonders in a fever ; and the 
