136 CONCHOLOGIST’S COMPANION. 
rubbed over with oil, it will change colour on being 
exposed to the sun in different degrees, and that 
exactly in proportion to the degree of transparency 
in each of the papers. 
These experiments were made in the months 
of January and February, by M. du Hamel, in 
Provence. 
The vividness of this beautiful purple renders it 
particularly valuable, especially as the pieces of 
stained cloth retain their colour: even if dipped 
several times in different liquors. 
The Buccinum as well as Murex, was used by the 
ancients for purposes of dyeing. They are both 
obtained in great plenty in the gulf of Tarentum, as 
well as in various parts of the Mediterranean.— 
Buccini of a prodigious size are also frequently sur- 
prised by Sicilian fishermen, asleep and floating on 
the smooth bays of the Mare Grande. 
The seas of the Spanish West Indies about Nicoya, 
furnish a shell-fish, which perfectly resembles the 
ancient purpura, and in all probability is the same. 
These fish, usually live about seven years: they 
conceal themselves in the sand a little before the 
commencement of the Dog-days, where they con- 
tinue for several months. On their reappearance 
they are collected in considerable numbers; and by 
rubbing them one against another, a kind of saliva, 
