8 INTRODUCTION. 



sometimes necessary to effect a perfect extraction. If a 

 large quantity of shells is to be cleaned, dissolve half a 

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

 quarts of boiling water, stirring it until all the particles 

 are dissolved, then pour it warm over the shells ; let 

 them remain in this liquid two or three days, frequently 

 warming it, and pouring it over them ; rinse them out 

 of this with a brush, and cleanse them well in warm wa- 

 ter. This method will generally be sufficient to. clean 

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

 When dry, brush them with a nail-brush ; and if they 

 are not dead shells, they will have a sufficient polish. 



Rugged shells generally require a different process 

 from the preceding, though it is prudent to try that me- 

 thod first. But when the shells are covered with adhe- 

 sions, or the epidermis will not separate from the shell, it 

 is necessary to use acid, which should always be applied 

 by a careful and skilful hand. After the shells have un- 

 dergone the foregoing process, and are dry, with a ca- 

 mel's hair pencil apply muriatic acid to the parts which 

 require it, dipping the brush in sand, and using constant 

 friction until the adhesions are removed. After this, 

 cleanse them with warm water, and dip them in alkali, 

 to neutralize the effects of any acid that may remain ; 

 and having again washed them in warm water, they 

 may be coated with a Aveak solution of gum-arabic. 



