Chap. 62.] HOW WOOLS ARE DYED. 445 



than any of them, that known by the name of " dialutensis," 68 

 because of the various natures of the soil on which it feeds. 

 Purples are taken with a kind of osier kipe 90 of small size, and 

 with large meshes ; these are cast into the sea, and in them 

 cockles are put as a bait, that close the shell in an instant, 

 and snap at an object, just as we see mussels do. Though half 

 dead, these animals, as soon as ever they are returned to the 

 sea, come to life again, and open their shells with avidity ; 

 upon which the purples seek them, and commence the attack, 

 by protruding their tongues. The cockles, on the other hand, 

 the moment they feel themselves pricked, shut their shells, 

 and hold fast the object that has wounded them : in this way. 

 victims to their greediness, they are drawn up to the surface 

 hanging by the tongue. 



CHAP. 62. (38.) HOW WOOLS ARE DYED WITH THE JUICES OF THE 



PUEPLE. 



The most favourable season for taking these fish is after the 

 rising of the Dog-star, or else before spring ; for when they have 

 once discharged 91 their waxy secretion, their juices have no 

 consistency : this, however, is a fact unknown in the dyers' 

 workshops, although it is a point of primary importance. 

 After it is taken, the vein is extracted, which we have 92 pre- 

 viously spoken of, to which it is requisite to add salt, a sexta- 

 rius 93 about to every hundred pounds of juice. It is sufficient 

 to leave them to steep for a period of three days, and no 



89 From the Greek iaAuro, "free," or "roving;" in consequence of 

 its peculiar mode of life. 



90 Nassis. See Note 51 in p. 421. 



91 " Quum cerificavere." Cuvier remarks that Aristotle, Hist. Anim. 

 B. v. c. 14, says, that these shell-fish make " waxen combs," meaning 

 thereby collections of cells, similar to those formed by the bee ; and it is 

 to this notion that Pliny refers in the use of the word " cerificavere." It is 

 the fact, Cuvier says, that the univalve sea shell-fish, and more particularly 

 the buccini and the murices, envelope their eggs with glutinous vesicles of 

 varied forms, according to the respective species ; which, when massed to- 

 gether, may be not inappropriately termed " combs." 



92 In c. 60. As Cuvier remarks, with considerable justice, this descrip- 

 tion by Pliny of the process of dyeing in purple, is very difficult to explain, 

 seeing that the art is now entirely lost. Reaumur, he says, made some 

 attempts at dyeing with a small buccinum found off the French coasts, the 

 Buccinum lapillus of Linnaeus ; but without any result. 



93 About twenty ounces. 



