(lichen) oddiar y cerig llwydion yn y cymoedd a'r carlegoedd. Defnyddid hwn at liwio; a chesglid ef y pryd hwnw gan y tlodion mewn rhanau o Loegr ac Ucheldiroedd Scotland yn gystal ag yn Nghymru. A byddai gan yr amaethwyr gynllun arall. Yn yr hâf casglent a llosgent lawer o redyn gleision er mwyn gwerthu eu lludw, yr hwn a ddefnyddid weithiau i wneuthur sebon, a phryd arall i wneuthur math o wydr.[1] Yn ei lyfr dyddorol ar NANWS Ach RHOBERT, dywed Elis o'r Nant ddarfod i Nanws y flwyddyn yr adeiladwyd y capel cyntaf yn Dolyddelen (1782) wneuthur naw punt oddiwrth ludw rhedyn, cyfran o ba rai a gysegrodd at y draul. Dywed iddi adeg arall wneuthur saith swllt oddiwrth y cèn a gasglasai, a rhoddi pedwar o honynt at adeiladu y capel cyntaf yn Ffestiniog. Gwerthai y lludw am chwe'swllt yr hôb, a'r cèn am geiniog a dimai y pwys. Ond nid ymddengys fod trigolion Corris wedi enill unrhyw hynodrwydd gyda'r fasnach, na sicrhau iddynt eu
- ↑ Yr ydym yn diyledus i'r Proffeswr Powel, o Gaerdydd, am y nodiadau canlynol, allan o Notes and Queries, ar y defnydd a wneid o'r lludw a'r cèn yn yr amser gynt:-"The fern referred to is no doubt the common brake (Pteris aquilina), the fronds of which are collected and burned in considerable quantities, for the sake of the ashes, not only in Wales, but in other parts of the country; these ashes contain a large quantity of alkali, and are made into cakes and balls, which form an article of trade, and are used as soap for washing, as well as by glass-makers. The lichen spoken of as being collected from the stones and boulders is in all probability Lecanora Tartarea, which is common species growing on boulders and rocks. Of this species we read in Lindsay's Popular History of British Lichens, that When Cudbear [dye)-making flourished in Glasgow and Leith, the Cud-bear lichen, so called, was largely collected in the Western Highlands and Islands by the poor peasantry, who were thus able to earn in 1807, according to Hooker, fourteen shillings a week. In Derbyshire and the rocky parts of Cumberland and Westmoreland it was also at one time collected by the peasantry, probably for the London market; they sold it to the manufacturer at a penny a pound, and were able usually to gather 20 or 301bs. a day."
"The lichen was most probably used for dyeing. It used to be employed for that purpose in the Highlands, and produces a dirty yellow."
"It may be well to note that Sir Thomas More knew that fern ashes were used in the making of glass. He says, 'Who wold wene it possible yt.glasse were made of fern rotys' (The Works of Sir Thomas More, Knight, 1557, fol. p. 125)."