410 
sense, in which it has been already applied to fossil wood, in the 
interstices of which clay has freely penetrated. 
On putting a piece of this wood, impregnated with lime, into 
diluted nitric acid, the same effects were produced as when other 
calcareous fossil wood was subjected to the same experiment. The 
carbonate of lime was decomposed, and, on the earth being removed, 
the fibres of the wood were found in a loose and detached state ; of 
a dark brown colour, and burning with a white flame, and a bitu- 
minous odour, on being applied to the flame of a candle. 
I have, in a former Letter, remarked that the process of bitu- 
minization seems to be inimical to animal life ; and that, after any 
vegetable substance has been exposed to its influence, it appears to 
be no longer fitted to become the aliment of any animal. Nature 
having now destined this matter to undergo a peculiar chemical 
change, the first step is to prevent its being subject to any other 
kind of alteration, which might interfere with this arrangement. 
This is confirmed by the appearance of these specimens, in which 
the wood has evidently been exposed to the process of bitumini- 
zation, since it had been subjected to the ravages of the teredines. 
These pieces of wood I therefore conjecture to have lain in the 
sea, subjected to the devastating labours of these animals, until, by 
some of those changes, of which a former letter has aimed to give, 
at least, some slight notion, they became overwhelmed with earth ; 
and that, while thus buried, and secluded from the atmosphere, they 
passed into the bituminous fermentation ; and afterwards, from the 
infiltration of certain lapidific juices, obtained their present form of 
existence*. 
* It seems to be deserving of trial, whether slightly bituminized wood might not be ad- 
vantageously employed for ships’ bottoms, and for other purposes, in which the ravages of the 
ship-worm are particularly required to be guarded against. It even seems desirable that it 
should be ascertained, how far wood which has been involved in hay whilst forming in the rick, 
would be protected against these animals. 
