25 
at the station where Mulgedium alpinum was originally found by Don, 
there were fine specimens of the Polypodium, two or more feet high, 
abundantly covered with sori. The same thing occurred a little above 
the track called Jock’s Road. In these localities the fern was associ- 
ated with fine specimens of Athyrium Filix-foemina. The party 
looked in vain for specimens of Carex Grahami in the old station in 
Glen Fiadh; and they failed in seeing Potentilla tridentata on the 
rocks near Loch Brandy, which is the station given for it by Don. 
Dr. Balfour noticed the heights at which the alpine species occurred, 
and exhibited a plan of the alpine district of Scotland, with specimens 
of the plants arranged upon it at their different altitudes. 
Dr. Balfour stated that, through the kind permission of Colonel 
Ogilvie, the party had the use of the large hall at Clova; and that 
Lord Castlereagh offered every facility for visiting Caenlochan Glen. 
Vegetable Substance formed in a Water-pipe. 
‘Note on a Vegetable Substance formed in a Water-pipe, at Haf- 
ion, Argyleshire ; by James Hunter, Esq. 
“ About twelve months ago, having occasion to bring in an addi- 
tional supply of water for the use of Hafton House, I had formed a 
small reservoir, or fountain-head, as it is called, from which to lead 
the water to the then only existing fountain-head, so as to increase 
the supply in the latter. The connexion between the two was by 
means of a burnt clay pipe, two inches in diameter, and in length 
thirty-six inches, securely fastened at the joinings with Roman cement, 
or mastic ; the total length of the piping being three hundred and 
twenty yards, secured at each end by zinc roses, four inches in diame- 
ter, in order to prevent any impurities passing through the pipe. 
When the work was finished, the supply of water was very good; and 
it continued so until a fortnight ago, when the running of the water 
through the tile piping gradually diminished, and at last almost entirely 
ceased ; a mere driblet, indeed, finding its way into the old fountain- 
head. Upon examination as to the cause of this change, by raising 
a considerable portion of the piping, there was found, about half-way 
between the two fountain-heads, the vegetable substance herewith 
sent. It was firmly lodged in one length of the piping, and projected 
an inch or so into another. 
“Tt is very curious to observe that the colour of the water pressed 
out of this substance, when first taken out of the pipe, and saturated, 
as it was, was deep brown; whereas the water itself flowing through 
the pipe to the very last was as pure as crystal.” 
VOL. IV. 10) 
