Fluorine in Recent as ivell as in Fossil Bones. 123 



The conclusion arrived at with respect to the compact form 

 of mineral phosphate of lime occurring in the above locality, 

 coupled with the reports of other chemists to the same effect 

 relative to crystalHzed apatite, naturally led me to speculate 

 as to the final causes of the apparently constant association of 

 fluoride of calcium with earthy phosphates amongst the older 

 materials of the globe, and to ask myself, whether it might 

 not be possible, that fluorine, as well as phosphorus, fulfilled 

 some hithei'to unexplained office, in the oeconomy of those or- 

 ganic beings, for the sake of which such mineral matters may 

 be conjectured to have been treasured up in the rock forma- 

 tions from the beginning of time. 



These reflections brought to my mind the researches of 

 Morichini and of Berzelius with respect to the existence of 

 fluorine in bones, seeing that the latter, according to the 

 concurrent testimony of both these philosophers, appear to 



calcium by repeated washings with water. I apprehend, however, that in 

 this method the whole of the fluorine may not have been driven over, in 

 spite of all the pains bestowed upon the process. 



I am desirous of appending the analysis given by Messrs. Middleton and 

 Campbell of the mineral, as though they differ, as might be expected, 

 somewhat from my own in the entire quantity of phosphate of lime pre- 

 sent in the specimens they examined, they confirm nevertheless my state- 

 ment .^s to the relation both between the phosphoric acid and the lime, and 

 between the phosphate of lime and fluoride of calcium present. 



The portion examined by Mr. Middleton was in the form of a brown 

 earth, containing nodules of a pure white, corresponding probably with the 

 original condition of the formation generally. The results of analysis were 

 as follow : — 



Phosphate of lime 73-66 



Fluoride of calcium 15*10 



Phosphate of iron 4-26 



Peroxide of iron . ri6 



Matter insoluble in acids 3*95 



Loss on heating to low redness after thorough drying "78 

 Loss in the process 1*09 



iWoo 



The constitution of the phosphate seems to be CaF-)- 2 (3CaO POj). 

 Analysis iy Mr, Campbell. 



1. 6'89 grains of a mixed substance, as received from Dr. Daubeny : — 



Phosphate of lime (SCaOPOs) . 4-78= 69-38 



Phosphate of iron. . . .~ . . '70= 10-16 



Fluoride of calcium 1-01= 14*66 



Peroxide of iron -02 = -29 



Insoluble matter in acids . . . -38= 5*5 1 



6-89 = lW00 



2. Analysis of white crystalline solid mass; 11-00 grains gave,— 



Phosphate oflime (3CaO PO5) . 8-68= 78-90 



Fluoride of calcium -63= 14-82 



Matter insoluble in acids ... -66 = 6*00 



Loss in experiment "03 = "28 



11-00=: 10000 



