3o6 The Commercial Products of the Sea. 



exhibit, the liquid of which we have been speaking must be 

 used in conjunction with that which was procured from 

 shell-fish belonging to other species. Some of the Tyrian 

 garments had a beautiful play of colours, like the shot silks 

 of our own time ; and this play of colouring, it is said, was 

 first suggested to them by having observed a similar one 

 upon the neck of a pigeon. With the destruction of the 

 ancient city of Tyre, the beautiful art of dyeing this 

 peculiar colour was lost for centuries, until it was again 

 recovered by the scientific men of our country ; and the 

 discovery would probably have been of much value to 

 commerce, had not the use of it been rendered unnecessary 

 by another natural history discovery, viz., the cochineal 

 insect. This has been again to a great degree replaced by 

 the discoveries of chemistry in the coal-tar colours. 



The Scalaria clathriis also furnishes a purple liquor of 

 considerable beauty, but it is destructible by acids, and 

 gradually vanishes by the action of light. The Planorbis 

 corneus likewise yields a scarlet dye, but of still less 

 permanency than the Scalaria, as all attempts to fix it have 

 hitherto proved ineffectual. 



In the reign of Augustus one pound of wool dyed with 

 Tyrian purple sold for about ^36 sterling. We need not 

 wonder at this enormous price when the tedious nature of 

 the process is considered, and the small quantity of dye 

 obtained from each mollusc. For 50 lbs. of wool the 

 ancients used no less than 200 lbs. of the liquor of the 

 Murex, and 100 pounds of that of the Purpura, being six 

 pounds of liquor to one of wool ; consequently the rich 

 Tyrian purple fabrics vied in value even with gold. 



Marine Silk. — Among the many novelties which industry 

 obtains from the sea, one of the most curious is the textile 

 product made with the byssus of the Pinnas of the Mediter- 



