Conchalogy. 347 



surface; but when this is poHshed, it loses at once its reticular 

 work, and its color, and becomes perfectly smooth, and of a 

 fine bright yellow. The violet-colored chama of New England, 

 when worked down and polished, is of a fine milk-white, with 

 a great number of blue veins, disposed like the variegations in 

 agates. 



The asses-ear shell or Haliotis asinina of Linnaeus, when polish- 

 ed after working it down with the file, becomes extremely glossy 

 and obtains a fine rose-color all about the mouth. These are 

 some of the most frequent among an endless variety of changes 

 wrought on shells by polishing; and we find there are many of 

 the very greatest beauties of this part of the creation, which must 

 have been lost had it not been for this method of searching deep 

 into the substance of the shell for them. 



The Dutch are very fond of shells, and are very nice in their 

 manner of working them: they are under no restraint, however, in 

 their works; but use the most violent methods, so as often to destroy 

 all the beauty of the shell. They file them down on all sides, 

 and often take them to the wheel, when it must destroy the very 

 characters of the species. Nor do they stop here ; but determin- 

 ed to have beauty at any rate, they are for improving from na- 

 ture, and frequently add some lines and colors with a pencil, af- 

 terwards covering them with a fine coat of varnish, so that they 

 seem the natural lineations of the shell. The Dutch cabinets are 

 by these means made very beautiful, but they are by no means to 

 be regarded as instructors in natural history. There are some ar- 

 tificers who have a way of covering shells all over with a differ- 

 ent tinge from that which nature gives them; and the curious are 

 often enticed by these tricks to purchase them for new species. 



There is another kind of work bestowed on certain species of 

 shells, particularly the nautilus; namely, the engraving on it fines 

 and circles, and figures of stars, and other things. This is too 

 obvious a work of art to suffer any one to suppose it natural. 

 Buonani has figured several of these wrought shells at the end of 

 his work; but this was applying his labor to very little purpose; 

 the shells are spoiled as objects of natural history by it. They 

 are principally wrought in the East Indies. 



Shells are subject to several imperfections; some of which are 

 natural and others accidental. The natural defects are those 

 of age, or sickness in the fish. The greatest mischief happens to 

 shells by the fish dying in them. The curious in these things 

 pretend to be always able to distinguish a shell taken up with the 

 fish aUvefrom one found on the shores; they call the first a liv- 



