58 _ Analyses of Books. (Jury, 
with all the. requisite care the different spots of a similar nature 
pointed out by Dr. Hutton, or his followers, near Edinburgh, but 
never was able to perceive the force of any of their conclusions. I 
was long ata loss to conceive what was meant to be conveyed by the 
term, indurated sand-stone. At last a friend-was good enough to 
show me specimens. I found that the indurated sand-stone of Dr. 
Hutton and his followers is the mineral well known by the name of 
fiinty slate. Dr, Macculloch mentions clay-slate as occurring in 
the rock of Stirling Castle. He obviously means slate-clay. 
XIV. On the Economy of the Mines of Cornwall and Devon. 
By John Taylor, M. G.S.—The mining concerns of Great Britain 
being all under the management of individuals, without any con- 
troul whatever on the part of government, cannot be expected to 
proceed with such regularity, or to be conducted with such skill, 
as in those countries where the whole has been for ages under the 
management of men educated for the purpose, and where every 
particular relating to the mines has been from the first carefully 
recorded. - Yet the improvements which have taken place in 
mining, especially in Cornwall, have been very great; and the 
vigour with which mining is carried on in that country is truly 
surprising. Mr. Taylor ascribes this in a good measure to the 
system which has been gradually introduced, and which he de- 
scribes. The owner of the soil lets the mine for 2} years to the 
adventurers, at a stipulated rate, which varies from =,d part of 
the ore raised, to 1th part, according to circumstances. The 
mine is usually divided into 64 shares, which are parcelled out 
among the adventurers. ‘The mine is under the charge of a prin- 
cipal captain or agent, who has under him several subordinate 
captains. ‘These are all practical miners of great skill and inte- 
grity. There are other subordinate persons connected with the 
mines, whom Mr. Taylor describes. The workmen are all em- 
ployed by the piece. The work to be done is put up to auction 
and given to the lowest bidder. These sales are open, and consi- 
derable competition often takes place at them. ‘The work to be 
done is of three kinds: tutwork, tribute, and dressing. 'Tutwork 
is done by measure, as sinking of shafts, driving of levels, stop- 
ping ground. Tribute is payment for raising the ore, dressing it, 
and rendering it marketable. Dressing is money given for dressing 
those parts of the ore which the tributers throw away. It is to 
this mode of raising ore by contract that Cornwall is indebted for 
the intelligence of its miners, and for most of the improvements 
in mining which have taken place in it. The ore, when dressed, 
is sold to the different tin and copper companies. 
XV. On the Origin of a remarkable Class of Organic Impres- 
sions occurring in Nodules of Flint. By the Rev. William Cony- 
beare, M. G. S.—This substance was first observed by Mr. Parkin- 
son, and thus described by him: ‘ Small round compressed 
bodies, not exceeding the eighth of an inch in their longest dia- 
meter and horizontally disposed, are connected by processes nearly 
