i6 Account of ike Peari FiJIiery in tht Gulph of Manar. 



water, to catch the drops of rain. One of the moft celebrated conchologlfts *, fuppofes 

 that the pearl is formed by the oyfter in crder to defend itfelf from the attacks of the/iAa- 

 lades and boreworms. But we maybe aflured that in this fuppofition he is miftaken, for 

 although thefe animals often penetrate the outer layers of the pearl fliell, and there occaGon- 

 hollow nodes, y^ t, on examination, it will be found, that they are never able to pierce the 

 firm layef, with ^hich the infide of the (hell is lined. How can the pearls be formed as a. 

 defence againft exterior worms, when, even on (hells that contain them, no worm-holes 

 are to be feen ? It is, therefore, more probable thefe worms take up their habitations in 

 the nodes, in order to prote(f!l themfelves from the attacks of an enemy, than that they are 

 capable of preying on an animal, fo well defended as the pearl-fifli is. It is unnecefl'aryto 

 repeat the various opinions and hypothefes of other modern authors i it is much eafier to 

 criticife them, than to fubftitute in their place a more rational theory. That of Reaumur, 

 mentioned in the memoirs oi the French Academy for 1712, is the moft probable, viz. 

 that the pearls are formed like bezoars and other ftones in different animals, and are appa- 

 rently the effefls of a difeafe. In fhort it is very evident, that the, pearl is formed by an 

 extravafation of a glutinous juice either within the body, or on the furface of the animal: 

 the former cafe is the moft common. Between one and two hundred pearls have been 

 found within one oyfter. Such extravafations may be caiifed by heterogeneous bodies, 

 fuch as fand, coming in with the food, which the animal, to prevent difagreeable fri£tion, 

 covers with its glutinous matter, and which, as it is fuccefTively fecreted, forms many re- 

 gular lamella:, in the manner of the coats of an onion, or like different ftrata of bezoars, 

 only much thinner ; this is probable, for if we cut through the centre of a pearl, we often 

 find a foreign particle, which ought to be conCdered as the nucleus, or primary caufe of 

 its formation. The loofe pearls, may originally have been produced within the body, and 

 on their encreafe may have feparated and fallen into the cavity of the fliell. Thofe eom- 

 pa£l: ones, fixed to the fhells, feem to be produced by fimilar extravafation, occafioned by 

 the fri£tion of fome roughnefs on the infide of the fliell, Thefe and the pearl-like nodes 

 have a different afpeft from the pearls, and are of a darker and bluer colour. In one of the 

 former I found a pretty large, true oval pearl, of a very clear water; while the node itfelf 

 was of a dark blueifh colour. The yellow or gold coloured pearl, is the moft efteemed by 

 "the natives ; fome have a bright, red, luftre ; others are grey or blackifti, without any 

 ihining appearance, and of no value. Sometimes when the grey lamella of a pearl is takea 

 off, under it is found a beautiful genuine one, but it oftener happens that after having fe- 

 parated the firft coat you find a worthlefs impure pearl. I tried feveral of them, taking on« 

 lamella off after another, and found clear and impure by turns, and in an impure pearl I 

 met with one of a clear water, though in the centre of all I found a foreign particle. The 

 largeft and moft perfeft pearl which I faw during my ftay at Condaichey, was about the fize 

 of a fmali piftol bullet, though I have been told fince my departure, many others of the 



The Rev. Mi'. Chemnitz at Coftnhagen.^ 



f^e 



