16 INTRODUCTION. 



mal to contract, and render it more easy to be extracted: 

 crooked pins, and other sharp instruments, are sometimes 

 required to effect a perfect extraction. 



If a large quantity of sliells is to be cleaned, dissolve 

 half a pound of potash, and half a pound of soft soap, in 

 two quarts of boiling water ; stir thfe solution until all the 

 particles are dissolved, and then pour it warm over the 

 shells; let them remain in tliis liquid two or three days, 

 frequently warming it, and pouring it over them. After 

 this process, wash them well with a brush in warm water; 

 and, when dry, rub them with a nail brush, until they have 

 received a sufficient polish. This method may be adopted 

 with all smooth shells, such as olives, cowries, cones, &c. 



Rugged shells generally require a different process from 

 the preceding, though it is advisable to try that method 

 lirst. But if they are covered with adhesions, or the epi- 

 dermis will not separate from the shell, it is also necessary 

 to use muriatic acid, after they have undergone the above- 

 mentioned process. When they are perfectly dry, the 

 acid is to be applied with a fine brush, dipped in sand, to 

 the parts which require it. After the adhesions, &c., are 

 removed, the shell must be immediately immersed in alkali, 

 to neutralize the effects of the acid, and then well washed 

 in warm water. As these shells are not susceptible of so 

 tine a polish as the smoother varieties, it is usual to give 

 them an artificial gloss, by brushing them over with a 

 weak solution of gum-arabic. 



Corals, which are so justly admired for their delicate 

 structure, elegant ramifications, and great beauty, may 

 be cleaned in a similar manner, by steeping them a few 

 days in the solution of potash and soft soap; after which 

 they should be carefully brushed in warm water. 



