[ 608 J 
why might not this be occafioned by the waters con- 
tained in the fpaces before defcribed, which, being 
impregnated with fulphureous fleams, were driven, 
up, and mixed with the waters of the fprings ? At 
leall, theie can be no doubt, by whatfoever means it 
was bi ought about, that this phenomenon was owing 
•to .the fame caufe, already beginning to exert itfelf, 
which afterwards gave rife to the fucceeding earth- 
quake. 
69. Something like this happened before the 
great Lifbon * earthquake of 1755. We are 
told, that at ■Colares, about twenty miles from 
thence, “ in the afternoon preceding the iff of No- 
vember, the water of a fountain was greatly de- 
cieafed : on the morning of the iff of November, 
it ran very muddy, and after the earthquake, it re- 
“ turned to its ufual ffate, both in quantity and clear- 
nefs.” The fame author fays, a little lower, « in 
the afternoon of the 24th, I was much apprehen- 
five, that the following days we fhould have an- 
other great earthquake; for I obferved the fame 
“ prognoses as in the afternoon of the 31ft Odlober; 
that is,” &c. “ And I farther obferved, that the 
“ water of a fountain began to be diflurbed to fuch 
a degree, that in the night it ran of a yellow clay 
<( colour; and from midnight to the morning of the 
25th, I felt five fhocks, one of which feemed to 
me as violent as that of the 1 ith of December.” 
70. But the moll extraordinary appearance of any 
»that preceded this earthquake, was that of the agita- 
* 5 ee f P T i‘ ilo , f - Tranf - vol. xlix, p. 416 and 417.— or Hift. and 
Fhilof. of Earthq. p. 313. ' 
tioil 
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