698 NATURAL HISTORY OF AQUATIC ANIMALS. 



oyster-beds, but they penetrate by digging burrows wherein their whole shell is lodged. Where 

 large numbers of these are present, with the help of boring-worms and sponges, they may so 

 riddle a reef as to cause its entire disintegration under the first gale. A fourth borer is Purpura 

 lapilhis, which is of interest in another direction. The famous Tyrian purple of ancient days 

 the regal dye that was deemed too splendid a color to be worn by any but kings arid nobles 

 was produced from a sea-snail, and conchologists have busied themselves to discover which 

 particular one. 



In the works of Pliny and Aristotle, the earliest sources of knowledge on the subject, the 

 information is too vague to be relied upon. Dr. Roth, of Munich, in a paper read before the Jeru- 

 salem Literary Society, says that several years ago (previous to 1857) he found at Jaffa the 

 Purpura patula, sought as food by the Christians during fast days : " On puncturing this animal 

 there issued a greenish liquid, which, when exposed to the sunshine, changed to purple. This 

 purple increased in brilliancy when it was washed." Comparing this with the accounts left by the 

 ancients, Dr. Roth thinks the color he produced is evidently their blue color, for they had a blue- 

 purple, a deep purple, and a red-purple. "Between Soor and Saida," according to the same 

 author, "the Murex truncatu,*, or trunculus, is found in abundance, and its color is more brilliant 

 than that of the Purpura. One of these Murex is sufficient to dye a square inch of cloth, which 

 would require five individuals of Purpura patula. Wool takes the dye better than any other 

 substance ; silk takes it with difficulty." 1 



Linton, in his work " On Ancient and Modern Colours," as quoted by Simmonds (" Commer- 

 cial Products of the Sea," p. 304), states that the Purpurce of the best description were chiefly found 

 on the rocks of Tyre, on the. coast of Asia. They were also collected at Miniuge, on the Grsetulan 

 shore in Africa, and on the coast of Laconia in Europe. The colors varied according to the 

 locality in which they were taken, and also according to the animal's haunt, as has since been 

 proved by zoologists. Thus, when it lived among sea-weeds or mud the juice it contained was 

 comparatively worthless ; when among pebbles its quality was improved; and the dye was best 

 when the food and surroundings were varied. Researches carried still further proved that to 

 produce the richest and most costly dye which art could exhibit, the liquid must be used in 

 conjunction with that procured from other shell-fish. Just what the species were that were used 

 it is now impossible to tell, but they were allied to Murex and Bucclnum. Niter, urine, water, salt, 

 and certain sea- weeds were also mixed with the Purpura liquor in compounding certain tints. " In 

 the reign of Augustus," says Simmouds, "one pound of wool dyed with the Tyriau purple sold for 

 about 36 sterling [about $175]. 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 uiollusk. 

 For fifty pounds of wool the ancients used no less than two hundred pounds of the liquor of the 

 Murex and one hundred pounds of that of the Purpura, being six pounds of liquor to one of wool ; 

 consequently the rich Tyrian purple fabrics vied iu value even with gold." 



The liquor was procured by placing the small shells in a mortar and crushing them. Animals 

 extracted from the larger shells were added, and also urine, pure water, or water in which purple 

 Snails had been allowed to putrefy. In this mixture the cloth was soaked and afterwards exposed 

 to the light, sometimes under the influence of warmth to accelerate the process. 



It is said that the dyeing property is a transformation of uric acid into purpurate of ammonia, 

 called murexide. This is a splendid substance when pure, presenting in one direction beautiful 

 metallic green reflections, and in others brown and purple tints. Some chemists assert that it is 



1 PlOPSON : Utilization of Minute Life. London Groombridge & Sons, 1864, p. 144. 



