NARRATIVE OF THE CRUISE. 
1035 
From the numbers found for jr it would appear probable that this bone contains a 
hydric phosphate such as MgHP0 4 , which I remember having seen reported in other 
bone analyses ; but I am more inclined to think that there is an unobserved error some- 
where. Taking the deficiency (17685 — 1 ’6949) in bases to mean a loss of magnesia,- 
we have for the percentage of that base 3'59 + 1‘47 = 5'06, which would bring up the 
total percentage to 100 '21. 
No. 12. Brain Case of Globiocephalus, European Seas. 
P. 
P. 
E. 
Phosphoric acid (P 2 0 5 ), . 
22-45 
0-9485 1 
Carbonic acid (C0 2 ), 
3-18 
0-1446 ( 
Chlorine 0-085 = (Cl 2 - O) or muriatic acid, 
0-066 
0-0024 f 
Sulphuric acid (S0 3 ), 
0-21 
0-0053 J 
Fluorine (F 2 ), .... 
0-004 
Lime (CaO), 
. 30-04 
1-0727 1 
Magnesia (MgO), .... 
0-38 
0-0190 
Potash (K 2 0), .... 
trace 
Soda (Na 2 0), .... 
1-62 
0-0623 J 
Phosphates of iron and alumina, . 
1-25 
Moisture, . . 
8-93 
Organic matter, .... 
. 31-79 
99-92 
The fluorine was determined in 8 grms. of the ash of the substance, and found to 
amount to 0'57 mgrms., that is to 0‘007 per cent, of the ash, or (P004 per cent, of the 
original substance. 
From these analyses it would appear that the percentage of fluorine in recent marine 
bones is very minute. 
For the sake of comparison, I determined the fluorine in a sample of ordinary bone 
ash,' and found it 0‘004 per cent., i.e., almost nil. 
As it is stated that teeth contain more fluorine than ordinary bones, I procured a 
quantity of horses’ teeth, ignited them, and determined the fluorine in the ash. It was 
found equal to 0’084 per cent. , which, though decidedly higher than the number 
obtained with the bones, is still very minute. 
I have no doubt that the 1 or 2 per cent, of fluoride of calcium, which we find reported 
in the older analyses of bones, is based on utterly erroneous determinations. This, 
however, only confirms what Nickles gave some years ago as the result of an extensive 
investigation on the subject. 
For the number of equivalents of carbonate present per equivalent of phosphate, we 
have in — 
No. 8. 
No. 11. 
No. 12. 
0-162 
0-197 
0-153 
1 
1 
1 
’ 6-2 
54 
6-6 
(NARR. CHALL. EXP. VOL. I.— 1885.) 
132 
