1844.] 431 



Mat 29, 1844. 



W. M. Hen. Browne, Esq., of King Street, Covent Garden, and 

 Geo. Locli, Esq., of Albemarle Street, were elected Fellows of this 

 Society. 



A communication was read by Professor Sedgwick, being in 

 continuation of his Memoir " On the Geology of North "Wales," 

 read on the 29th Nov. 1843.* The notice of this paper is post- 

 poned for the present. 



June 12, 1844. 



R. T. Atkinson, Esq., of Newcastle-on-Tyne, was elected a 

 Fellow of this Society. 



The following communications were read : — 



1. On Fluorine in Bones, its source, and its applicatio?i to the 

 determination of the geological age of Fossil Bones. By J. 

 MiDDLETON, Esq. F.G.S., late Principal of the College at Agra. 



The accumulation of fluoride of calcium in fossil bones constitutes 

 a very interesting and important subject of inquiry in reference 

 to Geology, since it seems to involve the element of time, so in- 

 teresting in all geological investigations. It was with a feeling of 

 this importance that I some time ago commenced a series of in- 

 vestigations, which are not yet completed, in order to ascertain 

 the proportion of fluoride of calcium in bones that had been pre- 

 served for various periods, with a view to infer, if possible, from 

 the mineral condition, the relative ages of the specimens. 



The bones hitherto examined by me with this view consisted of 

 some from the Sewalik Hills, furnished to me by my friend 

 Dr. Falconer, and some, for the permission to examine which I 

 am indebted to the authorities of University College, London, in 

 the chemical laboratory of which institution my investigations have 

 been conducted. Among these last were the bones of a Greek, who 

 had lived, it is supposed, about the time of the second Peloponne- 

 sian war (a coin of that period being found under the jaw of the 

 skeleton), and a part of an Egyptian mummy in a remarkably per- 

 fect state of preservation. The Sewalik fossils were of the soft 

 kind f , those imbedded in the clay in that locality, as they seemed 

 better suited for comparison with bones of recent and known age 

 and with those of early tertiary periods. 



On examining these bones, I found that those from India con- 



* See ante, p. 251. 



t So named, I believe, by the gentlemen who found them, to distinguish 

 them from those largely penetrated by oxide of iron or silica. 



