146 DR WILSON ON THE SOLUBILITY OF 



the fluoride in the recent bones of man and of the ox ; and ascertained the pro- 

 portion in which it was present in both.* On the authority of these chemists, 

 fluorine was ranked among the constituents of animal bodies. Many excellent 

 observers, however, soon after declared themselves unable to detect that element 

 in recent bones. Among these ai'e Foueckoy, Vauquelin,! Wollaston, Bkande, 

 Dr T. Thomson,! Gieaedin, Pkeisser, and Rees; § the last of whom is not con- 

 tent with stating that he found no fluorine in unburied bones, but affirms that no 

 one else can have met with it in them. More recently, Mr Middleton|| and Dr 

 Daubeny^ have experienced no difficulty in confirming the original results of 

 MoEicHiNi and Beezelius. An American observer has been equally successful.** 

 Dr Gregoey informs me that he has made many examinations for fluorine in 

 recent bones, and has always found it present in them. My own experience of 

 the subject is to the same effect. I shew the Society glass etched by recent hu- 

 man bones, male, female, and foetal, which were obtained, without special selec- 

 tion, from the dissecting-room ; likewise glass corroded by hydrofluoric acid from 

 the tusk of the recent elephant, and the teeth of the recent hippopotamus, walrus, 

 leopard, and shark. 



I shall return, in another section of this paper, to the consideration of the 

 question, how the discrepance in the statements of observers concerning the pre- 

 sence of fluorine in recent bones is to be accounted for. It was the occurrence of 

 that element in fossil bones which gave rise to the discussions concerning its origin, 

 to which I shall have occasion to refer. Fluorine is not a constant ingredient of 

 the animal remains in question, according to Foueceoy and Vauquelin, who 

 examined some which contained none. But in the greater number of cases it has 

 been found present, so that Gieaedin and Peeissee have even proposed to con- 

 sider its existence in an unknown bone as a proof of the latter not having be- 

 longed to man or to any recent organism, but to some " antediluvian animal." f f 



It is acknowledged, moreover, that in bm-ied bones, especially in those that 

 are petrified, fluorine is frequently present in larger proportion than in recent 

 ones. Thus Lassaigne found fifteen per cent, of fluoride of calcium in the bones 

 of the Anoplotherium;!! MiDDLETONten per cent, in those of various animals from 

 the Sewalik Hills ;§§ Gieaedin and Peeissee nine per cent, in those of the La- 

 mantin. || 1| Mr Middleton, indeed, has endeavoured to shew that the proportion 

 of fluoride of calcium increases according to the period of the entombment of the 

 bone at the rate of 1^ per cent, in a thousand years, and has proposed to estimate 



* Annales de Chimie, torn. Ixi. (1807), p. 256. t Ibid., 1806, t. Ivii., p. 41. 



J Chemistry of Animal Bodies, p. 236. 



§ Guy's Hospital Reports, quoted in Edin. Phil. Joui-nal, vol. xxviii., p. 93. 



I Chemical Society's Memoirs, vol. ii., p. 135. ^ Ibid., p. 101. 



** Edin. Phil. Journal, vol. xxxix., p. 235. ft Ann. de Chim., t. ix. (1813), p. 381. 



JI Quarterly Journal of Geological Society, vol. i., p. 216. §§ Ibid. 



nil Ann. de Ch. et Ph., t. ix., p. 375, 1843. 



