146 DR WILSON ON THE SOLUBILITY OF 
the fiuoride 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 are Fourcroy, VAUQUELIN,+ WOLLASTON, BRANDE, 
Dr T. THomson,{ GirarDIN, PreissErR, 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 MippLErTon|| and Dr 
DaAvuBENY have experienced no difficulty in confirming the original results of 
MoricuinI and BerzEeLIus. An American observer has been equally successful.** 
Dr Grecory 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 Fourcroy and VAUQUELIN, who 
examined some which contained none. But in the greater number of cases it has 
been found present, so that GrrARDIN and PREISSER 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.” + 
It is acknowledged, moreover, that in buried bones, especially in those that 
are petrified, fluorine is frequently present in larger proportion than in recent 
ones. Thus LAsSsAIGNE found fifteen per cent. of fluoride of calcium in the bones 
of the Anoplotherium;{{ MippLETOoN ten per cent. in those of various animals from 
the Sewalik Hills ;§§ Grrarpin and PREISsER nine per cent. in those of the La- 
mantin. || || Mr MrppLeTon, 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 14 per cent. in a thousand years, and has proposed to estimate 
* Annales de Chimie, tom. Ixi. (1807), p. 256. + Ibid., 1806, t. lvii., p. 41. 
{ Chemistry of Animal Bodies, p. 236. 
§ Guy’s Hospital Reports, quoted in Edin. Phil. Journal, vol. xxviii., p. 93. 
|| Chemical Society’s Memoirs, vol. ii., p. 135. q Ibid., p. 101. 
** Edin. Phil. Journal, vol. xxxix., p. 235. tt Ann. de Chim., t. ix. (1843), p. 381. 
{{ Quarterly Journal of Geological Society, vol. i, p. 216. §§ Ibid. 
I|l| Ann. de Ch, et Ph,, t. ix., p. 375, 1843. 

