UNNEAN SOCIETY OF LONDON. 25 



adopted in the text-books and in edncated public opinion, as 

 expressed in Sir Edwin Arnold's lines : 



" Know you, pei'chance, how that, poor formless wretch — 

 The Oyster — gems his sh:ill<jw luooii-lit chalice? 

 Where the shell irks him, or the sea-sand frets, 

 This lovely lustre on his grief." 



There is no doubt that occasionally a grain of sand does form the 

 nucleus of a free pearl. Mr. llornell and I found three such, out 

 of hundreds of pearls examined, in the course of our Ceylon 

 investigation. But as a rule any such foreign inorganic matter 

 introduced between the mantle and the shell gives rise only to a 

 pearly or nacreous excrescence attached to the shell. Artificial 

 pearls of an inferior sort are, however, sometimes produced in this 

 way ; and the practice in China of forming rows of nacreous beads 

 or images of a Joss, or of Buddha, on the inner sia-face of the 

 freshwater Dij^^sas plicaius, Leach, depends simply upon the fact 

 that foreign bodies placed outside the mantle w-ill be cemented to 

 the shell by a layer of nacre. 



It is generally believed amongst naturalists that LinnsDUS was 

 foi' some time engaged in an endeavour to produce artificitil 

 pearls ; but few, if any, seem to know what his process was, and 

 what it resulted in. The literature of pearl -formation contains 

 various vague references to Linnseus's " secret process,'' but no 

 descri])tion of it, excej)t an article in Swedish by Fahr^eus in 

 1852*. In Pulteney's 'General View of the Writings of 

 Linnaeus ' (2nd edit., London, 1805, p. 93) it is stated ; " We are 

 unacquainted with the means by which he accomplished this 

 extraordinary operation, but may observe that it is probable .... 

 that the n:ethod consisted in injiu'ing the shell externally, perhaps 

 by a perforation . . . . " &c. Such a recent work as Dr. Lyster 

 Jameson's " Origin of Pearls " (Proc. Zoo). Soc. 1902) states that 

 "Chemnitz, Beckmann, and others (1791) regarded Linnoeus's 

 ' secret ])rocess ' as merely boring the shells. However, no sub- 

 sequent boring experiments have yielded anything but blisters, 

 and the popular notion of Liunseus's modus operandi is little more 

 than a guess." That being so, you will be interested to hear that 

 our own Linnean library and the collection here has recently 

 afforded me the means of making known to you the trutli as to 

 this " guess." 



We have amongst the treasures of our library a manuscript 

 volume labelled " Linnaeus on Pearls," given to the Linnean Society, 

 in January 1871, by Oscar Dickson of Gothenburg, and attested 

 by Jacob P. Bagge to be a true copy in Swedish [on the left-hand 

 pages] and a faithful translation f into English [on the right-hand 

 pages] of the original documents which were in his possession 



* Ofvers. K. Vet.-Akad. FGrh., Arg. 16. No. 3, p. 39. 



t The translation is not perfect in all respects. I am indebted to my friend 

 Mr. Havald Ehrenborg, Swedish Consul at Liverpool, for help iu determining 

 some points in the Swediih. 



