INTRODUCTION. XV 



as those of the marine species, but they form links in the testaceous 

 chain, which are necessary to a proper study and elucidation of 

 conchology. 



The most glowing and gorgeous of all shells are those brought 

 from the Tropical seas, and, excepting in a few rare instances, 

 specimens of most of these can be obtained at little cost from any 

 dealer, or from sailors returning from a voyage. If it is necessary 

 to send either those, or British shells, any distance, or to pack 

 them away in a small compass, the best plan is to wrap them 

 separately in soft paper, place them in a box, and then pour in 

 sawdust, bran, or fine sand, very dry, until all the open spaces are 

 completely filled up. 



ON CLEANING AND POLISHING SHELLS. 



All shells, whether inhabited or not, when taken should be 

 soaked for a while in hot water, to remove the dirt which may 

 adhere to them, and dissolve the saline, that is salt, particles con- 

 tained in the sea water; they should then be thoroughly dried, 

 and if, as is the case with many, they naturally possess a good 

 polish, they are at once fit for the cabinet. Generally, however, 

 it happens that when shells are dry, they lose much of the 

 peculiar brilliancy of hue, which they possess when seen through 

 the medium of the glistening water; to restore this, wash them 

 over with a thin solution of gum arabic, or white of e^g; some 

 collectors use a varnish made of gum mastic, dissolved in spirits 

 of wine; this is perhaps preferable, as it is not affected by moisture. 

 Many shells have a very plain, dull, appearance, in consequence 

 of being covered over with a kind of skin called an epidermis, 

 a word derived from the Greek, and signifying the outer skin, 

 sometimes called the cuticle. To remove this, soak the shell in 

 warm water for some time, and then rub it over with a stiff 

 brush until the covering is removed; should this be very thick, 

 it will be necessary to mix a little nitric acid with the ^^ater, but 

 this must be done very cautiously, for if too strong it will remove 

 all the lustre from the surface of the shell subjected to its in- 

 fluence. Sometimes the file, and a substance called pumice stone 

 has to be used, but these are dangerous agents in inexperienced 

 hands. The best polish for the shell after the skin is removed, 

 is a red earth called tripoli, applied on a piece of soft leather. 



FOSSIL SHELLS. 



An eminent Geologist, named Dr. Mantell, has very beautifnlly 

 and poetically termed rocks "The Medals of Creation." As on coins 



