C 120 ] 
not in any regular ffrata, but interfperfed in large 
mattes through the earth, and which proved to be 
martial j of marcafites, which yieldedmear one tenth 
part of common fulphur ; of cornua ammonis of dif- 
ferent fizes, and other {hells, but of the bivalve clafs, 
which were crufted over, and as it were mineralized, 
with the pyritical matter; of belemnites, alfo crufted 
over with the like fubftance: and the cliffs, for near 
two miles long, and from the furface, to 35 or 
40 feet deep, even to the rocks at high-water mark, 
were one bed of a dark coloured loam, flrongly 
charged with bitumen. Moreover, 1 found alfo a 
dark coloured fubflance, refembling coal-cinder ; 
fome of which being powdered, and wafhed in di- 
f tilled rain-water, upon filtrating the water, and eva- 
porating it flowly to a pellicule, its falts fhoot into 
tine cryflals, and appear to be no more than a mar- 
tial vitriol : one ounce of this cinder-like fubftance 
yields one drachm of fait. I gathered up about one 
hundred pounds weight of the different kinds of thofe 
pyritae, marcafites, &c. which were laid in a heap, 
expofed to the air, and every day fprinkled with 
water : the confequence was, that, in about ten days 
time, they grew hot, foon after caught fire, burned 
forfeveral hours, and fell into duff. Hence, there- 
fore, it is imagined, that thefe martial and fulphurous 
foflils, by being expofed to the air and wet, by being 
agitated by the beating of the fea, and, if I may ufe 
the expreffion, by being electrified by the fubtil flame 
of the lightning, take fire, which is favoured by the 
bituminous particles contained in the loam, and burn 
till all their phlogiffon is confumed, and their iron, 
or martial earth, is dilfolved in the acid of fulphur ; 
which 
