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with the edges partly blunted. The inner figure on the same 

 line was given me by Mrs. Abbot of Bedford, who picked it 

 up in Derbyshire. The smallest of the two lowest ones is ap- 

 parently a fragment, remarkable for the resemblance to part 

 of a septarium ; the inner part resembling the upper right 

 hand figure with a coat of a different colour. • The largest 

 figure at the bottom has a resin-like appearance, which these, 

 stones occasionally have, and was given me by D. Turner, 

 Esq. who brought it from Ireland. Agates that are found 

 in Scotland resemble all these ; but what are found there, 

 especially near Perth, are admired for being striped, zoned, 

 forming onyxes, or speckled with various blots, &c. resem- 

 bling eyes. Mocoas are a sort of agate with dendrites or 

 figures like sprigs, trees, &c. which seem to be iron, some 

 say manganese, formed in a peculiar manner with the stones, 

 especially the oriental ones, which are durable) but those 

 called German Mocoas by the lapidaries, seem to have had 

 the branching figures introduced by nature or art into their 

 flaws, and such are apt to disappear, often to the great 

 disappointment of the wearer. We digress a little in speak- 

 ing of these, which are foreign subjects, as we do not yet know 

 of any stones worthy to be termed Mocoas found in Great 

 Britain. 



We consider agate to be nearly of the same nature or a 

 variety of chalcedony. It is said to contain Silex 84, Argil 16. 



P 2 



