Some Account of certain Agates. 173 
dies could not be kept burning, for the duration of five days and 
nights ; but were at length fortunately extricated by a drift be- 
ing driven from an adjoining mine. In this case | am led to 
think the quantity of deleterious gas had been less considerable 
than at Heaton. 
I have now only to remark, that the bodies of those men which 
had laid in wet places were much decayed; but where the floor 
was dry, though their flesh had become shrivelled, they were all 
easily recognised by their features being entire. 
p Yours, 
Newcastle-upon-Tyne, March 4, 1816. N. 
P.S.—Eleven more corpses remain undiscovered in the re- 
cesses of the mine. 
XXXIX. Some Account of certain Agates presenting by an arti- 
ficial Arrangement the Aspect of organized Bodies. By 
M.Gitrer DE Laument, Engineer to the Mines of France*. 
M. Moreau DE St. Mery, having brought from Italy some 
agates found in the bed of the Trebia, which discharges itself 
into the Po near Plaisance, sent a polished one to M. de Mont- 
egre, who showed it to me at the Institute on the 9th of Oct. 
1815. 
I immediately observed that the appearance of the organized 
body which this agate presented seemed to have been given it by 
art. We showed it afterwards to several naturalists, who at the first 
glance thought they saw in it the marks of the wood of the palm- 
tree; while others thought they saw the traces of a marine body. 
In fact, this agate presents in the middle some round conical 
bodies penetrating into the stone, the summits of which are 
at the surface, aud the united bases of which form an appear- 
ance of a network with hexahedral meshes: in other parts of 
the stone we find only small insulated cones with circular bases. 
Having for a long time remarked the fractures which the 
blows of a hammer produced on hard and homogeneous stones, 
1 had ascertained that under the place where the blow was 
given cones were formed, the summ:t of which was at the point 
of contact, and of which the base was sunk more or less re- 
gularly into the stone; and I had thus formed with fine free- 
stone the lustrous freestong of Haiiy. According to this ob- 
servation, | think I may venture to say, that the appearances of 
organized bodies in the agate in question had been formed by 
‘blows adroitly given and struck in succession beside each other. 
* Communicated by the Author. : 
I even 
