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XVI. — On the Solubility of Fluoride of Calcium in Water, and its relation to the 

 occurrence of Fluorine in Minerals, and in Recent and Fossil Plants and Ani- 

 mals. By George Wilson, M.D. 



(Read April 6. 18i6.) 



1. Introductory Remarks. 



The investigation I am about to bring before the Royal Society, was under- 

 taken in consequence of a discussion which took place in the Zoological Society 

 of London in 1843,* in reference to the chemical composition of the bones of the 

 gigantic bird the Dinornis, discovered some time previously in New Zealand. At 

 the meeting in question, the distinguished paleontologist Dr Falconer drew 

 attention to the frequent, if not constant, occurrence of fluoride of calcium in fossil 

 bones, and, as he stated, also in those of mummies ; and threw out the sugges- 

 tion, that the fluoride might shew itself in these animal remains, not as an origi- 

 nal ingredient of the bones, or as derived from the matrix in which they were 

 found, but as a product of the transmutation of their phosphate of lime. The 

 idea of such a conversion taking place, is as old at least as the days of Klaproth, 

 who suggested the possibility of phosphoric acid becoming changed into fluoric.f 

 It is commented upon by Fourcroy and Vauquelin,!: as well as by Gay Lussac,^ 

 as a thing possible but not probable, and which their ignorance of the nature of 

 fluoric acid prevented them from discussing satisfactorily. 



The revival of this suggestion by Dr Falconer, at a period when the possi- 

 bility of the chemical elements undergoing transmutation was occupying the 

 attention of English chemists, and avowedly with a view to shew at least the 

 possibility of such an idea proving true, excited much discussion, and led, I be- 

 lieve, to the researches of Mr Middleton and Dr Daubeny, which I am presently 

 to mention, and of which my own may be considered the sequel. I have to re- 

 quest the forbearance of the reader, whilst, with as much brevity as possible, I 

 refer to the labours of my predecessors in relation to the presence of fluorine in 

 different bodies. 



In 1802, Morichini of Rome discovered fluoride of calcium in the molars of 

 a fossU elephant, and was led, in consequence, to search for it in the enamel of 

 recent human teeth, where he also found it. || His results were confirmed by 

 Gay Lussac, who experimented along with him,^ and by Berzelius, who found 



* Literary Gazette, Dec. 2. 1843, p. 779. t Annales de Chimie, tome Ivii. (1806), p. 43. 



I Ibid., p. 44. § Ibid., torn. Iv., p. 265. 



II Ibid., p. 258. t Ibid. 



VOL. XVI. PART II. 2 O 



