RovAL Society. 329 
coIIe(5led by the fubterraneous heat, diftil into the matrix of 
amber, which afforded both a dormitory and place of retreat to 
thefe infe6ts, they are covered thereby, and when that bitumen 
becomes amber, they are plainly feen within it ^ what confirn^s 
this conjeflure is, that moll of thele infefls, that are buried in 
annber, are of that kind, which chule caverns for their dor- 
mitories; the greateft part appear languid, or (limy; fuch as 
are lively make an effort to fpread their wings, and difentangle 
themfelves, but thele are rarely to be found. 
The mofl beautiful pieces of amber are luch as have buds of 
plants within them : M. Hartman had one piece in which the ex- 
panded leaves of the veficular fea-weed reprefented the extended 
wings of an eagle, with its body and feet ; another piece contained 
a feed of the tile tree and a part of the trunk ; another had an 
open pod with four leeds, out of which arole an j4pex in the 
middle, the Imall ftalk being prominent and extending to the fu- 
perficies of the amber; another prefented to view mofs, that was 
arched like a balcony ; another appeared like a little flower that 
was faded ; in another there was a branch of wild rofemary with 3 
leaves upon it; and thro' another rough piece was feen a large 
branch of the abovementioned veficular fea-weed : M. Hartman 
reckoned the amber in which herbs were included to be more 
beautiful than that in which animals are inclofed. 
Minerals are likewife inclofed in amber ; vitriol is foon dilco- 
vered by its tafte ; lometimes Tyrites^ and oftentimes iron is 
found therein; alfo gold and filver in the impure amber; drops 
of water are likewife oblerved in feveral parts thereof; which is 
either fait, brackilh, or fometimes infipid : M. Hartman lup- 
poled that thefe plants or minerals had alio dropped into the ma- 
trix, and were there furrounded with the bituminous liquor; and 
there is a particular method of accounting, how drops of water 
come to be in amber; and it is this, a warm bitunninous exhala- 
tion encompafles the moift matrix, the water driven inwards, 
cannot be evaporated by the fubterraneous heat and by realbn of 
the circumambient bituminous liquor can find no pafTage out, but 
is detained there. 
Amber is not to be reduced to the clals of metals, as being 
neither f ufible nor dudile ; and when brought into fufion, it loles 
much of its firmnefs, which is never the cafe as to metals; fomc 
have pretended to the art of melting amber, and of re-uniting its 
fmall broken pieces without impairing its hardnefs ; but M. Hart^ 
man found by leveral experiments that no fuch thing was pradi- 
cable, becaufe the falts, wherein the greateft firmnefs of amber 
Vol. Ill, T t con- 
