24 



PURPURA. 



The ancients seemed to have managed the 

 extracting process in rather a clumsy manner; 

 but it is easy enough to procure the dye without 

 mixing it with the juices of the animal, as seems 

 to have been the case in the olden times. If the 

 reader would like to try the experiment, it may 

 be done as follows : — 



Let him look among the rocks at low water, 

 and plenty of the shells may be found tolerably 

 close together. When a sufficient number are 

 collected, they should be killed by placing them 

 in fresh water, after the shell has been pierced 

 or broken, as otherwise the animal shuts itself up 

 so tightly that the water cannot gain admittance. 

 When the creatures are quite dead, the colouring 

 matter may be found in a yellowish-looking 

 vessel, that derives its colour from the substance 

 contained within. There is very little of this 

 colouring matter in the vessel. Now, if this 

 yellow substance be spread on white paper and 

 placed in the sunshine, a blue tinge enters the 

 yellow, making it green. The blue gradually 

 conquers the yellow, and the green soon becomes 

 blue. Another colour, red, now makes its appear- 

 ance in the blue, and turns it into purple. The 

 red becomes gradually stronger, and in its turn 

 almost vanquishes the blue, but does not quite 



