496 MR MILNE ON THE GEOLOGY OF ROXBURGHSHIRE. 



kinds. All these conclusions, to which the theory necessarily leads, is utterly 

 inconsistent with observation. 



A third theory has been lately propounded by Mons. PAEEOT, in describing 

 " les pierres d'Imatra," which, judging from his elaborate account, and still more 

 from the beautiful lithographic figures he has given of them, I think are identical 

 with the stones of both kinds mentioned in the first part of this Memoir, as found 

 in Elland and Kale Waters. This author maintains that " les pierres d'Imatra 

 sont des moUusques petrifie'es, sans coquellis." He modestly declines, however, 

 " to classify this new family of molluscs," leaving that labour to other zoologists ; 

 but he does not hesitate to name it, as one the existence of which can no longer 

 be doubted, and the name he gives to it is Imatra, in honour of the place where 

 it was first discovered. 



This extraordinary theory is very zealously supported in a Memoir which 

 extends to 130 quarto pages, and is illustrated by no less than sixteen plates, 

 occupied partly with views of the locality, but chiefly with figures of the stones, 

 of which there are nearly 100.* The stones so figured are identical in size, 

 shape, and appearance, with those described in the present Memoir; and the 

 chemical analysis given by Mons. PARBOT, appears to be in entire accordance with 

 the composition of the Roxburghshire stones. I have read with attention the 

 arguments which he advances in support of his theory, that they are molluscoxis 

 animals in a fossil state ; but I confess that they have neither convinced nor in- 

 fluenced me. They have left only a feeling of surprise, that so extraordinary an 

 inference should have been adopted on such slender evidence. 



In the first part of this Memoir I expressed an opionion, that these fairy 

 stones are concretions of clay produced by the homogeneous attraction of its par- 

 ticles. Though Mons. PARROT notices this hypothesis, and endeavours to combat 

 it, I think his arguments altogether futile, and several of his facts not a little 

 confirmatory of it. From the analysis which he gives of these stones of Imatra, 

 the following are the proportions of the substances composing them : 



Carbonate of lime, ....... .49 



Silica 19 



Alumina, ........ .12 



Oxide of iron, ....... .13 



Sulphur, 04 



Water ... .01 



.98 



Mons. PARROT gives also an analysis of the clay which contains these nodules, 

 and which consists of sand .32, silica .37, alumina .13, and oxide of iron .15, =.97. 



* This Memoir was published at St Petersbourg in 1840 by the Imperial Academy of Sciences. 



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