+ Aristotle, de Hist. Animal. lib. v. cap. 
p. 272. . 
On the Economical Uses of some species of Testacea. 239 
the description and plate given, he appears to have made use of the 
common periwinkle (Buccinum Lapillus, Linn.) for this purpose. 
On trying the experiment himself, the writer found the color to 
vary much, and frequently before attaining its final hue. At first it 
was pellucid and nearly colorless, then became a light green, and if 
placed in the sun, immediately much darker ; in a few minutes it 
changed to a full sea green, and after that into a watchet blue; ina 
few minutes more it was a purplish red, and after lying an hour or 
two became a very deep purple. Further than this the sun did not 
affect it, but on being washed in soap and water it changed to a very 
bright and brilliant crimson. When the article dyed with it lay in 
the sun, it emitted a very strong and fetid smell, as if garlic and as- 
safcetida were mixed together. More lately a species of shell was 
used by the Spanish Americans at Nicoya, also for dyeing with, but 
the cloth thus prepared was so expensive as only to be worn by the 
nobles.* Among the Romans the royal edicts were frequently 
signed with this liquor, and it was used as a pigment by artists. 
In common with the rest of the genus, the fish is carnivorous and 
locomotive, living sometimes in deep water, and sometimes burying 
itself in the shore, while it is constantly searching for food. The 
coloring liquor is probably provided as a means of defense to the ani- 
mal, as the ink of the cuttle fish, or the saliva of the snail; and 
although we have never observed the fact in any American or Brit- 
ish species, the fish when touched is said to have the power of volun- 
tarily emitting it.t In which case it comes out purple, and of a very 
rank and offensive odor. If this be so, it must undergo some change 
in passing through the vein, as when cut out it is white, and long in 
attaining its purple and final hue. Since the discovery of America, 
and the introduction of cochineal into Europe, the fish dye has been 
entirely neglected as an article of merchandise, and is not, that we 
are aware of, any where used in the present day. 
VII. Murex Trrronis, (Linn.)—Trumpet Shell. 
This fine univalve is indigenous to most warm climates ; it inhabits 
the African, American, and Asiatic seas, and is found on the coasts 
of the islands of the southern Pacific. The only use it appears to 
* Rees’ Cyclopedia. Article Purpie Fisx. 
Recs 15. Hughes’ Nat. Hist. of Barbadoes, 
