28 THE SEA-SIDE AND AQUARIUM. 



Should any one, after a perusal of this description, 

 feel desirous to procure a few spots of royal purple, 

 his wishes can be readily gratified, by following the 

 directions of a naturalist who flourished two centuries 

 ago. This was William Cole, who appears to have 

 been the first, in modern times, to discover that the 

 common Dog-winkle yielded the famous dye of the 

 ancients : 



" Having supplied yourself with a few of these 

 animals, break the shells with a smart stroke with a 

 hammer, and then throw them into some fresh water, 

 in which they quickly die; care, however, must be 

 taken so as not to crush the body of the fish within 

 the shell. The broken pieces being picked off," says 

 Mr Cole, " there will appear a white vein, lying trans- 

 versely, in a little furrow or cleft next to the head of 

 the fish, which must be digged out with the stiff 

 point of a horse-hair pencil, being made short and 

 tapering. The letters, figures, or what else shall be 

 made on the linen (and perhaps silk too), will pre- 

 sently appear of a pleasant light-green colour, and, 

 if placed in the sun, will change into the following 

 colours : that is, if in winter, about noon ; if in 

 summer, an hour or two after sunrising, and so 

 much before setting, for in the heat of the day in 

 summer the colour will come on so ' fast that the 

 succession of colours will scarcely be distinguished. 

 That to the first light-green, it will appear of a deep- 

 green, and in a few minutes change into a sea-green ; 

 after which, in a few minutes more, it will alter into 



