S50 Dr Traill on tlie Mineralogy of Hatkin Mountain^ 
Hoskell/ near the town of Flint. There are copper- works along 
the coast, but they are not supplied by the mines of this coun- 
try. No considerable body of copper has yet been discovered 
in Flintshire ; but the produce of the mines of Anglesey and 
other parts of Wales, are here converted into bars, wire and 
sheetSj both for boilers and sheathings by means of machinery 
wrought by the copious stream which bursts out from the saint- 
ed spring of Winifred, and gives a name to the romantic and 
busy town of Holywell. I may here remark, that this cele- 
brated spring diminishes one-third, or even more, in great 
drought; and though usually limpid, I have seen its waters of 
a muddy whey-colour after heavy rain. Its temperature is 
considerably above that of the medium temperature of the cli- 
mate, and it appears to vary at different times. In 1820, when 
muddy, I found it 57° Fahr. ; several years ago it was as high 
as 59°) but it is said usually to be 58°. These variations are 
remarkable in a spring which pours out in its usual state twenty- 
one tons of water minute. It is remarkable alsoj that most 
of the European thermal springs occur in limestone countries. 
The third range of hills is the lofty ridge which, under dif- 
ferent names, forms the eastern boundary of the fertile vale of 
Cwyd. On the slopes towards the Dee, it consists of a hard 
and pretty compact limestone, in tracing which, from Diserth 
to Caergwrle and Llangollen, many years ago, I found the 
limestone to contain encrinites and other corallites, and it ap- 
peared to rest on highly inclined strata of an argillaceous-slate, 
which constitutes a large portion of North Wales, and would be 
considered by the Wernerian geologists, as belonging to rocks 
of Transition. The limestone, which rises into a lofty mountain 
just above Diserth, appeared to me to have the characters of 
what is called the oldest floetz-limestone, abounding in galena 
and calamine, which, near Mold, are accompanied by compact 
and earthy sulphates of barytes, as vein-stones. 
Such is the general distribution of the mineral products of 
this part of North Wales. We shall now examine more parti- 
cularly Halkin^Mountains long celebrated for its lead-mines, 
and now become additionally interesting by the discovery of the 
valuable buhr-stone, and the fine porcelain-earth above noticed ; 
premising that the lead-mines of this place are either wrought 
