1888.] 



The Chemical Composition of Pearls. 



463 



microscope, the structure of the mother-of-pearl of the shell and 

 of pearls is almost identical. 



[One can scarcely imagine that the analyst could have possibly 

 employed in his investigation a piece of shell while it was yet in a 

 fresh and consequently moist state. 



As regards the hardness of pearls, again, it may perhaps be as well 

 for us to remark that good pearls have a much denser texture than 

 the majority of persons appear to suppose, as may be gleaned from 

 the following facts. 



On one occasion being desirous to crush into powder a split-pea 

 sized pearl, we folded it between two plies of note-paper, turned up 

 the corner of the carpet, and placing it on the hard bare floor, stood 

 upon it with all our weight. Yet notwithstanding that we weigh over 

 12 stone, we failed to make any impression whatever upon the pearl, 

 and even stamping upon it with the heel of our boot did not suffice so 

 much as to fracture it. It was accordingly given to the servant to 

 break with a hammer, and on his return he informed us that on 

 attempting to break it with the hammer against the pantry table, all 

 he succeeded in doing was to make the pearl pierce through the paper 

 and sink into the wooden table, just as if it had been the top part of 

 an iron nail, and that it was not until he had given it a hard blow 

 with the hammer against the bottom of a flat-iron that he succeeded 

 in breaking it. 



In addition to the foregoing we may likewise take occasion to 

 mention that shell-fish pearls are not nearly so easily dissolved in 

 strong vinegar as the interesting tale of Cleopatra having taken a 

 large pearl from her ear, and, after having dissolved it in vinegar, 

 drunk it to the health of her lover Antony, would lead one to believe. 

 For during our experiments we have learned that not only does it 

 take many days to dissolve out the mineral constituents of a large 

 pearl in cold vinegar, but that it even requires several hours to extract 

 the mineral matter, by boiling vinegar, from a pearl not bigger than a 

 garden pea. While in neither case, moreover, can the pearl be thus 

 made to disappear, as from the fact of the organic matrix of a pearl 

 being totally insoluble in vinegar, even after every particle of its 

 earthy substance has been removed, it still remains of the same shape, 

 bulk, and almost identical appearance as before. Hence we fear that 

 if the Cleopatra legend is to be believed at all, it requires considerable 

 modifications ere it can be brought into harmony with scientific truth. 

 There is, indeed, only one way in which a large pearl, such as the one 

 Cleopatra is said to have employed, could be dissolved in vinegar at 

 a supper-table, and that is by having it completely pulverized by a 

 hard hammer and a strong arm before applying the vinegar to it. 

 For once the mineral constituents of a pearl have been reduced to the 

 state of an impalpable powder, they not only readily dissolve, but 



