NOTES AND QUERIES. 



295 



NOTES AND QUERIES. 



Geological Pearls. — " The inquiry in a late number of The Geologist, 

 * Have geologists ever found any fossil pearls among the oyster and other beds of 

 fossil shells ? ' has induced me to fon\-ard the result of some investigations which 

 I have very recently been caiTying on, not originally with the expectation of dis- 

 covering pearls, but, having observed in several instances bodies in chalk which I 

 have thought fit to denominate ' pearls,' I will at once proceed to tell you the 

 tale respecting them ; premising that I am aware they are not the bodies which 

 your correspondent ' Enquirer ' is in search of 



" I have been employing and amusing myself by examining microscopically spe- 

 cimens of chalk from various localities. I followed the method of disintegratmg 

 the chalk, ' by scrubbing it with a nail-bmsh in water,' adopted by Mr. Lonsdale. 

 The first specimen I examined was taken from a drifted mass of chalk lying upon 

 the Kimmeridge Clay in a pit at Ely ; on placing minute portions of it, moistened 

 with water, in the field of my microscope, I observed, among the particles usually 

 met with, a number of spheres of various magnitudes, such as I had never heard 

 of before ; the majority of them are perfect circles, having the appearance of 

 slightly depressed spheres, their smface exhibits a slight degTee of polish, and 

 some are certainly subpellucid ; such is the appearance of these bodies when 

 viewed under a thin stratum of water, with transmitted light ; but, if examined 

 when dry, with reflected light, aided by tlie bull's-eye, they are opaque, with a 

 subcrystalline, marbly surface ; in short, when seen under water, they reminded 

 me so of the ' urinary pearls ' occasionally met with in the bladder of the horse, 

 that I have been induced to term them 'geological pearls.' They are soluble 

 in dilute hydrochloric acid. I have crushed them, with the desire of seeing if their 

 internal structure be fibrous, as in ' minary pearls,' but I have not at present 

 succeeded in detecting that stnicture. It is probable that they may possess a 

 central nucleus, inclosed in concentric laminae, as in oolitic bodies. I am decidedly 

 of opinion that the spherical is the characteristic fonn of these bodies, still I have 

 seen some of an oviform, or pyriform, and, very rarely, a bilobed, form; if any may 

 be said to be amorphous, those have a somewhat botryoidal surface. 



" In the chalk from Cherry Hinton, near Cambridge, I found plenty of 'pearls,' 

 and an abundance of Rotaline and Textulariae. In a fragment of chalk-marl from 

 Burwell, in Cambridgeshu-e, I did not detect any of the spherical bodies. Grey 

 chalk from Whittington, near Stoke Ferry, in West Norfolk, a stratum of the 

 lower chalk, contains an abundance of the ' pearls.' Foraminifera appeared to be 

 not very numerous ; but, as the portion of chalk examined was exceedingly minute, 

 the proportion of these organisms cannot be accurately judged of The chalk of 

 Swan ham (medial chalk) furnished great plenty of 'pearls;' that also from 

 Hitcham, in its vicinity, contains these ' pearls,' but not in such abundance as 

 the chalk of Swaff'ham ; in it I observed one of a pyriform shape, or rather oviform, 

 with a stem to it. 



" The Norwich Chalk (upper chalk) has about the same proportion of 'pearls' 

 as the chalk from Hitcham, and an abundance of Foraminifera. 



" Where they are most abundant, you meet with a regularly graduated series of 

 these bodies, from the smallest to the largest ; and by measurement I found the 

 former of an inch in diameter, the latter 2^0, so that, if allowed to be those 

 precious bodies, we m.ust consider them ' seed-pearls ' only. The above described 

 bodies are very unlike Xanthidia. — C. B. Rose, F.G.S., Great Yaraiouth." 



The Chapter on Fossil Lightning. — "Dear Sir,— There is an error about 

 Dr. Fiedler's Dresden specimen, at page 203, which is sure to be noticed, unless 



