Bigger — Prehistoric Settlements at Portnafeadog. 731 



to the province of Guayaquil the finest purple is found. The animals 

 from which it is derived are contained in shells ahout the size of 

 walnuts, and live on rocks washed by the sea. They contain a juice 

 or humour, which is taken out, and yields the true purple. This 

 humour to all appearance serves the animal instead of blood. Cotton, 

 thread, and other delicate materials, are dyed with it. It gives a 

 lively and durable colour which does not lose its lustre by frequent 

 washing, but is rather improved thereby, and does not fade through 

 long-continued use and exposure. Near the port of JSTicoya, in the 

 province of Guatemala, the same kind of shell-fish is found, and is 

 used for dyeing cotton. In both places -the dyed yarn is employed 

 in making ribands, lace, and other articles, which are afterwards 

 skilfully sewn and embroidered. All such articles are highly prized 

 on account of their fine and rare colour. Various processes are em- 

 ployed for extracting the juice or humour. Some kill the animal. 

 They take it out of its shell, and, having laid it on the back of the 

 hand, press and squeeze it with a knife from the head to the tail, and 

 then separate the expressed juice, the rest of the animal matter being 

 thrown away. They treat in this way a number of animals until 

 they have a sufficient quantity of juice. They then draw through 

 the thread which they wish to dye, and no more is required. But 

 the dyed threads do not show at once the purple colour they should 

 have. This is not perceived until the whole is thoroughly dry. At 

 first the colour is milk-white, then it becomes green, and finally 

 purple. Others express the juice without killing the animal. They 

 do not take it entii'ely out of the shell, but only press it so as to 

 cause a certain quantity of humour to be ejected, with which the 

 threads are dyed. The shells are then laid again on the stones from 

 which they were taken. They recover, and after some time give a 

 fresh quantity of juice, but not so much as the first time." 



Although I can produce no positive proof to show that the 

 Purpura at Portnafeadog were used for dyeing purposes, yet the 

 facts that such dye was in common use amongst the ancients, and 

 that the animal was poor food or bait, and yet the shells were found in 

 large quantities, go a long way to substantiate my theory that this shell- 

 fi.sh was gathered and broken for the dye it contained. The following 

 note from Bede has an interesting bearing upon the subject : — 



Beda, " Histoeia Ecclesiastica Gentis Anglokum." 



" Optima frugibus atque arboribus insula, &c. . . . Sunt et 

 cochleae satis superque abundantes, quibus tinctura coccinei coloris 



