THE 
AMERICAN NATURALIST 
Vou. X XIX. April, 1895. 340 
ON THE PRESENCE OF FLUORINE AS A TEST FOR 
THE FOSSILIZATION OF ANIMAL BONES. 
By Dr. THomas WILson. 
The discovery of the existence of fluorine in animal bones 
was made by Morichini in the early years of the nineteenth 
century, and was soon thereafter confirmed by the leading 
chemists, although there were considerable discussions and 
some disputes in regard to its presence. Berzelius in his 
Trait? de chimie, Vol. VII, page 473, 1833, reports having cer- 
tainly found it in animal bones, but says it was less than two 
per cent. About the same time, Gay Lussac, in his lectures 
-before the Faculty of Science, says that the fluoride of cal- 
cium exists in the proportion of about one one-hundredth in 
the composition of bone and the enamel of teeth. On the 
contrary, in 1843, Girardin and Priesser, in their Memoire sur 
les os anciens et fossiles, in the Annales de physique et de chimie, 
1843, Vol. III, page 370, declare that they have not been 
cable to find the least trace of fluoride of calcium in ancient 
human bones, and that the existence of this salt in recent 
animal bones is more than doubtful. But this difference was 
all put to rest and beyond doubt by the investigations of 
Mons. Fremy in his Recherches chimiques sur les os, Annales de 
physique et de chimie, 1855, Vol. I, page 47. But it was, as they 
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