i Dr. Troost on Amber, &. 
2d.- Sia ian insect aoe its nidus of resinous. eee, as the 
coccus la 
8d. What species < of trees do these insects inhabit? Pe 
~- Note Second, p. 10. Sahatcke seems to have adopted this bed of 
lignite as its laboratory for the formation of sul phur, of which the 
pyrites are composed—at least, it is true, that above this bed not 
the least vestige of this miner al is to be found, whereas, it appears 
as soon as the lignite is discovered In the s superior part the py- 
and there, the: sand which exists in the interstices: of the w 
a “by pyrites, and at other times, uniform piesa or 
ich we have made mention in this is memoir, are large masses. of 
oes found principally in the inferior part of the stratum, at a 
spot where the water has been prevented from: infiltering itself to 
a lower depth, by the bed of earthy Ment saseliad be which (as i in the 
case of comt water r does not ¢ ry ws but with g 
the pr structure of wood; or tie dips oF sandstone which 
serves as a cess to the eet we find small masses of sand ce. 
potiaceacih by ‘pyrites. cr necansetn is gan aa ten or twelve 
propo wat 
ao density it has acquired, in its passage, , by the solution of for- 
eign matter. Below this bed, of which the meant tuck » s three 
a tes are formed. 
What sh all ll we conclude from all this ? ‘Here I faced hawiva 
my op ion. first suppose the constituent parts of 
the sulphur’ are lodged in the vegetable matter—that only an active 
agent is wanting to disengage them from the matter with which 
they are combined, and to recombine to produce sulphar— 
let us suppose, at the same time, this. agent to , or water 
charged with iron, then the water, by filteri h the superior 
stratum, which, en said, js sand agglutinated by oxide of 
iron, is charged with the iron, and meeting in the stratum of lignite 
the constituent parts” of eUaeer has” put the same into action. 
Phe sulp! ing ni tae: entered j into pombinatlag with 
thefiae place, tc he pyritous matter, panty ag in 
| ned by a decor athe 
form and 
~The ligud thus. generate, tering 
. ee Dr. Trovst consider itp a3 a compound ?. Fa. 
Bee aa are eek te ia hia i bo ta gc eth oy nll 4 
