1895.]; Fluorine as a Test for the Fossilization of Animal Bones. 318 
The first column of figures gives the proportion of phos- 
phoric acid, the second the proportion of fluorine, the third 
gives the calculated ratio of this proportion of fluorine to that 
of an apatite having an equal amount of phosphoric acid. 
gr) 
| ; g 
| © 8 
| S > e 
| < Q a = 
ie = z= 
Bones of Modern Animals. E B Z 
eae 3 E 3 
Fs li 
A : 
= 
| > 
A S sc eat 
; | 
Human Femur—Body | 40,91 0,17 0,05 
Human Femur— Head | 41,20 0,18-.| - 0,06 
Human rib 36,80 0,22 | 0,06 
Bone of Ox 40,10 0,25 | 0,07 
Boné. OF OR ys oci us se soesvaesale. Gisiasss-vosess 40,32 0,238 | 0,06 
Bone of Elephant 41,24 0,23 | - 0,06 
Tooth of Elephant—Dentine.... csee ........es0066/ 41,77 0,21 0,05 
Modern Ivory 46,12 0,10 0,02 
Bone of Manatee 38,93 0,31 0,09 
Bone os 38,03 0,27 0,08 
ne ytina giga 39,52 0,24 0,07 
ne of White Swan 38,20 0,19 05 
Shell of the Trionyx . essees] | 37,54 0,13 0,04 
ne of Testudo radiata 38, 0,17 ,05 
Bone of-large Serpent...............cseceeee sesseesesenees 42,16 0,21 0,05 
ile 40,88 0,16 0,04 
Bone of TB eciine. Sedvcctevesteccobeteicansneseccececs 40,91 0, 0,07 
n pine ‘ur cane 40,96 0,11 0,05 
Bone and Spine of Codfish....... 41,27 0,24 0,06 
Bone and Spine of Pike. 38,26 | . 0,16 -0,05 
It can be seen from this table that the amount or quantity 
of Fluorine in these modern bones is always between 0,16 and 
0,31 p. 100, while the amount of phosphoric acid in the same 
is between the limits of 37 and 42 p. 100 (the ivory being an 
exception). The relation between the amount of fluorine with 
that of phosphoric acid in the normal apatite is found to be 
between 0,05 and 0,07 per cent, the exact average for the 20 
analyses being 0,058. T 
