16 
This process of staining is now said to be “ lost ” to the trade, 
and the old specimens are highly prized. I take it that the same 
might be easily effected with an analine dye. 
Specimens of odontolite are not very rare to the trade, but 
the colour is usually of a deeper blue than is proper in a 
turquoise, and more resembling vivianite or phosphate of iron 
proper. 
One. of the largest known pieces of vivianite (the scapula of 
Bos) was given by me to the Museum of the Royal School 
of Mines, Jermyn Street, London, and was found on the Castle 
Hill, Hastings, in excavating. Perhaps, if exposure to sulphate 
of iron was carried to excess the deeper colour of Vivianite 
might be obtained in the experiment above mentioned. 
On the whole the genuineness of the turquoise colour of this 
particular tooth must be considered doubtful as a natural 
product, though there is every reason to suppose that the colour 
may occur naturally in other specimens. 
WEDNESDAY, FEBRUARY 8ru, 1898. 
On invitation of the Council, the Photographic Section 
exhibited to the members generally, by the Electric Lantern, the 
Slides which had competed for prizes during the year. 
eee” 
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