216 



PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Hills, and a bone of the Anoplotherium ; the latter being given by 

 Lassaigne : — 



Organic matter 



Recent 

 Bone. 



Bone of 

 the Greek. 



Fossil Rumi- 

 nant, from the 

 Sewalik Hills. 



Bone of the 



Ano- 

 plotherium. 



33-43 



997 









Phosphate of lime 



52-11 



7001 



78-00 



37-00 



Carbonate of lime 



10-36 



10-34 



1 1 -34 





Fluoride of calcium 



1-99 



5-04 



10-65 



15-00 



Chloride of sodium - 



•60 



| 1-15 







Soda - 



1-08 



1 . 





Magnesia - 



•76 



} 1-34 



>-a trace 





Phosphate of magnesia 



•00 







Silica -.'--- 



— 



1-68 



— 



35-00 



Peroxide of iron 





about -25 







Alumina - 



. — 



— 



— 



10-00 



Oxide of iron & manganese 









3-00 



In comparing together the quantities of fluoride of calcium in 

 bones of different periods, we should be guided, I apprehend, by 

 the proportion it bears, in each specimen, to the fixed basis of the 

 bone, phosphate of lime, a substance which seems but little liable 

 to variation in amount. The comparisons stand thus : — 



Phosphate of Lime. 

 Recent bone - - 52-11 - 



The Greek's bone - - 70 -01 - 



The Sewalik fossil bone - 78-00 - 

 The Anoplotherium bone - 37*00 - 



Fluoride of Calcium. 

 1-99 

 5'04 



- 10-65 



- 15-00 



When the animal matter, entirely obliterated in the fossil bones, 

 has been suppressed in the recent bones, we have — : 



Phosphate of Lime. 

 Recent bone - - 77*84 - 



The Greek's bone - - 78-55 - 



The Sewalik fossil bone - 78-00 - 

 The Anoplotherium bone - 37 -00 -■ 



Fluoride of Calcium. 



- 2-97 

 5-62 



- 10-65 



- 15-00 



If now, for convenience of computation, we represent the phos- 

 phate in each case by 100, we obtain the following ratios of the 

 fluoride : — 



Recent bone - - 3*81 



The Greek's bone - - 7*15 



The Sewalik fossil bone - 13*01 



The Anoplotherium bone - 40*54 



Now, as the age of the Greek's bone is known to be 2000 years, 

 we obtain, if my hypothesis be just, the following values, in time, of 

 the above rations of the fossil bones : viz. the Sewalik fossil, 7700 

 years ; the Anoplotherium, 24,200 years. 



