Pofition per- 
pendicular. 
Inclined. 
Horizontal. 
SECT. V. 
Ufe of fif- 
fures. 
I4 6 natural history 
tradion, which formed the mailer-vein, gradually ceafed and died 
away, the fubordinate cracks and little fide-veins, proceeding late- 
rally from the fame forces, became lefs and lefs as they became 
more diftant from the chief fource of motion. 
Fiffures are either perpendicular, inclined, or horizontal. The 
general pofition of fiffures, at firft, was probably the perpendicular 
or near it ; for it is a common obfervation, that the fifiure, which 
inclines much near the furface, grows gradually more upright, 
as it fhoots deeper into the earth, where the flrata are ufually more 
compad, and confequently more apt to have preferved the primary 
pofition than thole which are nearer the furface, and therefore 
more liable to have been difturbed. 
Fifiiires inclined (that is, deviating from their perpendicular, as 
indeed moft of them do) owe their obliquity partly to the firft 
irregular contradion of the flrata , and partly to fome after-violences, 
whereby the neighbouring flrata were unfooted, and, in proportion 
to their own fubfidence, inclined and bent from their natural pofi- 
tion every thing in their reach, as will more clearly appear in the 
examination of the properties of lodes in the following chapter. 
Horizontal fifiiires are owing probably to the accidental interpo- 
fition of hard and different bodies, whereby the flrata were kept 
from contad and fettling dole upon one another, and partly to the 
different efforts of the upper and under maffes at their firft indu- 
ration. By either of thefe caufes, or by both conjointly, horizon- 
tal chafins in the flrata might be formed ; but they are much lefs 
frequent than the perpendicular and inclined. We find them 
fometimes replete with metals and minerals, and call them floors, 
not lodes. 
Some fiffures are quite broken and difcontinued, and the deferted 
fragment, from which they have been divided, found again at a 
final 1 diftance : this is alfo the effed of violence, and will come to 
be particularly explained among the properties of lodes. 
Although thefe fiffures are the natural refult of a moiftened and 
mixed congeries of matter, palling by approximation of parts into 
a ftate of folidity and drought, we are by no means to conclude 
them ufelefs, or the works of chance, produced without or befide 
the defign of the firft caufe : No ; the great Archited, who con- 
trived the whole, determined the feveral parts of his fcheme fo to 
operate, as that one ufeful effed fhould become the beneficial caufe 
of another. God provided for the ufes of things in his firft ideal 
difpofition of them, and their refpedive beneficial ufes flowed na- 
turally from each other thus aptly difpofed. Hence it happens that 
matter could not contrad itfelf into folid large maffes without 
leaving 
