C 193 ] 
lay it before this illuflrious body, I accordingly 
obeyed ; and the inclofed is the faid paper. My avo- 
cations, which now abforb many hours I formerly 
dedicated to fludy, have been the only caufe, my 
Lord, that I have detained it fo long; I therefore 
hope for your Lordfhip’s and the Society’s pardon. 
When I firft undertook the tranflation, I had 
thoughts of giving my opinion thereon, not only by 
reafoning, but alfo by experiments. Time, my Lord, 
has not permitted me to do fo ; and f nee, having 
ferioufly reflected, that Mr. Hubner, in his laid para- 
graph, turns his intire fyflem into a partial produc- 
tion of one fpecies of Tripoli, I think it unneceffary to 
trouble your Lordfhip, or the Society, with any ar- 
guments pro or con. I fhall only obferve, that it is 
not improbable but fome of Mr. Hubner’s Tripoli, as 
he furmifes, may have been produced from the petri- 
fied wood he found in the mountain ; and the whole 
account is then reduced to this only circum fiance, 
that the layers of foffil wood in this mountain, hav- 
ing been faturated with the Tripoline particles, which 
likewile abound in the fame mountain, thereby com- 
poled a ftone, or third body; and that afterwards 
thefe Tripoline particles were again reduced, by the 
effeds of a fubterraneous fire, to their priftine date ; 
the force of the fire defixoying the compages of the 
third body, or (tone. 
Had the wood, my Lord, been faturated with any 
other metallic mineral, or earthy particles, I believe 
every judge of fcience will determine, that the calci- 
nation of petrified wood, alone, could never have 
changed it into Tripoli. 
I have, in my hiflory offofiils, p. 76. 87. and 87, 
deferibed five kinds of the Tripoli earth; and Mr, 
V 0 l. LI. C c Hub- 
