Manchester Memoirs, Vol. Ix. (191 6), No. 7. 21 



D'Argenville, in his " Conchyliologie (1742, p. 181), 

 states that the " Conque Persique " is made use of both in 

 Panama and Guatemala for dyeing purposes and, on that 

 account, is called " Poupre de Panama." The " Conque 

 Persique " {Purpura persica) inhabits the Indian Ocean, 

 and was distinguished from the Purpura patula of the 

 Pacific coast by Brugiere in 1789 and Lamarck in 1803. 



In 1744, Don Antonio de Ulloa saw at S. Elena, in 

 what is now Ecuador, and also at Nicoya (Costa Rica), 

 purple colour produced from sea-shells. He describes the 

 process in his " Physical and Historical Account of 

 Southern and North-Eastern America " as follows : " On 

 the coasts belonging to the province of Guayaquil the 

 finest purple is found. The animals from which it is 

 derived are contained in shells, about 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 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 washings, but 

 is rather improved thereby, and does not fade through 

 long-continued use and exposure. Near the port of 

 Nicoya in the province of Guatemala the same kind of 



shell-fish is found, and is used for dyeing cotton 



Various processes are employed 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 Others 



express the juice without killing the animal. They do 



