Source of Fluorine in Fossil Bones. 237 



tions, it would seem, ought certainly to contain a portion of 

 whatsoever matter had been infiltrated, as all infiltrations 

 must have passed in together. These concretions, carefully 

 detached from the bone, were examined especially for fluo- 

 rine, but not the slightest trace was found ; while, on the 

 contrary, a very small quantity of the compact part of the 

 same bone gave decided indications of the presence of this 

 substance. This fact must certainly lead to the conclusion, 

 that the fluoride of calcium in the body of the bone was not 

 infiltrated ; for, had it been otherwise, it would have been 

 associated with matter known to be infiltrated, as the calca- 

 reous nodules. 



The same cellular bone was examined as a whole — that is 

 to say, without detaching the calcareous matter, in com- 

 parison with the compact bone from the same locality ; and 

 in the former there was found less fluoride of calcium than 

 in the latter, contrary to what would have been the case had 

 this fluoride been infiltrated. 



Compact bone, . • 2-45 per cent, fluoride of calcium. 



Cellular bone, . • 2-00 



The deposit from which these bones were taken was ana- 

 lyzed, and fluoride of calcium detected, but in very small 

 quantity ; and whether it arises from disintegrated osseous 

 matter, or belonged originally to the calcareous remains 

 forming this bed, is of no consequence ; sufiicient is it for 

 us to know, that it has an organic origin, having been a part 

 of either mollusca or vertebrated animals ; and were it ne- 

 cessary to suppose that it could have existed in only one of 

 those, I should unhesitatingly attribute its origin to the ver- 

 tebrated animals, particularly on account of their abundant 

 provision of phosphates. Bones were also exammed that 

 contained fluorine, when the deposit from which they were 

 taken shewed no traces of this element. 



Dr Daubeny has lately examined the question of the exist- 

 ence of fluorine in recent bones, and decided it in the affir- 

 mative. , , , , , 



It is not surprising that we should find the phosphates 

 and the fluorides associated in the animal kingdom, for, m the 



