156 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. 



3. On the Existence of Fluoric Acid in recent Bones. By G. 

 Owen Rees, Esq., M.D. 



The author in this communication wished to direct the atten- 

 tion of geologists to the experiments connected with the presence 

 of fluoric acid in bones that have undergone no change consequent 

 upon fossilisation. He states that in the experiments he made, 

 the bones were tested both before and after calcination, but that 

 there was nowhere the slightest indication of fluoric acid in recent 

 human bones, although immediate evidence of its presence was 

 obtained when fossil ivory was submitted to examination. 



The analyses of fossil bones have, according to Dr. Rees' state- 

 ment, shown the existence of a very large proportion of fluoride, 

 in some cases as much as 10 or 15 per cent., which is an enormous 

 increase on the largest proportion ever declared to exist in recent 

 specimens. He argues, therefore, that since so much of the 

 fluoride of calcium is introduced in fossilisation, the whole may 

 have been. 



He concludes by alluding to the unsatisfactory state of the 

 question at issue, namely, whether the bone and ivory while under- 

 going the process of fossilisation have their phosphoric acid 

 transmuted, or whether a fluoride exists undetected in the soft 

 parts of animals, which during their decay decomposes the earthy 

 salts of the bones. 



April 17. 1844. 



H. B. Mackeson, Esq., of Hythe, and Sir Thomas Edward 

 Colebrooke, Bart., of Colebrooke Park, were elected Fellows of 

 this Society. 



The following communications were read : — 



1. Observations on the Geology of the Southern Part of the 

 Gulf op Smyrna and the Promontory of Karabournou. By 

 Lieut. T. Spratt, R.N. 



The observations contained in this paper continue the subject 

 from the point at which it was left by Messrs. Strickland and 

 Hamilton in their memoir on the geology of the neighbourhood of 

 Smyrna*, and relate to the western boundary of the lacustrine 

 deposits which lie to the south of the town of Smyrna, forming 

 and in part surrounding the plain of Sedi-kieui ; so called from a 

 village of that name situated on its western margin. 



Immediately over the village there rises a series of ridges, flank- 

 ing a high mountain that forms one of the principal features in 

 the arm of land which separates the two gulfs of Smyrna and 



* Geol. Trans. 2d ser. vol. v. p. 393. 



