212 



GASTEROPODA. 



A purple liquor, capable of producing a rich and permanent dye, is known 

 to be produced by many Gasteropods ; but various species of the animals in- 

 habiting these rock-shells are pre-eminent for this property. Accordingly, we 

 are told that they furnished the first colour which mankind was enabled to fix 

 permanently on wool and linen. While a certain person, called Hercules, strolled 

 along the shore with his lady-love and her dog, the latter in its sport mouthed 

 a shell which had been tossed up by the waves, and had his lips coloured by 

 the purple juice. The lady, enchanted with the beauty of the colour, yearned 

 for a dress of the same purple, and the wish sufficed to call into exercise the 

 ingenuity of her lover, who succeeded in dyeing her a garment. The Tyrian 

 purple was perhaps the principal commodity of Tyre, when her " merchants 

 were princes, and her traffickers the honourable of the earth." 



222. GRANULATED TROCHUS. 



FIG. 223 PELICAN'S-FOOT STROMBUS. 



The dyeing material is contained in a tube of yellow or cream-colour that 

 mris diagonally across the body of the Murex. If this be cut with a sharp 

 l>uir of scissors it gives issue to a creamy substance, which is the colouring 

 fluid. When applied over linen with a camel-hair brush, the hue is at first a 

 rich "king's yellow," but changes in a few minutes to a delicate pea-green. 

 1 n about an hour, if the weather be cloudy, it has become of a yellow grass- 

 .ureen, from which it slowly turns to a blue-green, thence to indigo, then to 

 blue a red tinge next becomes apparent then violet, then a purple more or 

 less tinged with red, till at length, after five or six hours, without direct sun- 

 light, it assumes its final tint, a rather dull purplish crimson or lake. Exposure 

 to the sun greatly hastens the process. 



There have been found on the shore near the ruins of Tyre a number of 

 round holes cut in the solid rock, varying in size from that of an ordinary 

 metal pot to that of a large boiler. Within these, and on the beach, were a 

 great number of shells broken apparently by design. It is hence supposed 

 that the animals were pounded in these mortars for the purpose of extracting 

 the colouring fluid, especially as Pliny describes this as being the mode in 

 \vhich the dye was obtained. The shells, when examined, proved to be those 

 of Murcx trunculus, still found abundantly on the neighbouring beach. 



The Stromb-Shells (Strombus) have the siphonal canal straight, or in- 

 flected towards the right side. The external border of the opening of these 

 shells expands with age, and sometimes spreads out into long finger-like pro- 

 longations, so that, when they arive at maturity, their form is very different 



