offer a few o f them, which have all the appearance of
being deciiive in favour of my fyftem («).
There are no pebbles more lingular than thofe cryftal-
line ones found in the bed of the river Henares, near
San Eernàndo; now if thefe pebbles had any progreffive
motion, let it be ever fo fmall, they ought certainly by
this time, after fo many ages, to have reached the bed
of the Tagus fo near them, yet none are to be found
there.
The Tagus is full of calcareous ftone at Sâcédon ;
a little lower, at Aranjuez, not one of thefe is to be
found in its bed.
In the kingdom o f Jaen near Linares, there is a hill
chiefly compofed o f round fmooth ilones, about the fize
o f an egg ; the fmooth poliih of thefe and their round-
nefs cannot be attributed to rains, becaufe they are not
expofed to them, nordifperfed on the furface of the hill,
but buried underneath at a eonliderable diftance: nor
touch lefs can it be attributed to any river, for I do not
know from what fyftem, or by what chronology, it may
be conjetftured that any river ever run over that eminence.
fa) Mr. Bowles tells us, he looks upon this as one o f thé happieft difcoveries he ever
fttade, as ftriking him in a forcible light, and fervirig as â key tending to illuftrate the true
phyfical theory o f the earth ; but in what maimer it had this efftd. he has not inibrrtied us.
In
Irt the village of Maria, three leagues above Zaragoffa,
there is a broad gully full o f quartz, fandftone and lime-
ftone, and gypfum of a perfeft white, yet at Zaragoffa
the Ebro contains none o f thefe forts.
I believe no body has ever feen in the bed o f Lhe Ebro1
large or fmall round granite ftone, nor blueiih ftone
veined with white, hut the Cinca before it empties
itfelf into that river is full of them : in fo much that it
carries no other fand but thefe ftones reduced very fmall,
near San Juan in the valley of Giftau..
The river Naxera is lull o f fmall fandy ftone,. and of
white quartz refembling little almonds, mixed with others
of a red colour. This river runs into the Ebro, in whofe
bed when it paffes by Zaragoffa, none of thefe forts of
ftones are to be feen.
The bed of the Guadiana has in its different parts the
fame kind of pebbles as are found on its banks, and on
the adjacent hills, without being mixed with thofe that
are found a league higher or lower ; and at Badajoz,
where the country is without any ftone, none are to! be
found in the bed of the river.. ; i
This holds good' not only in Spain, for I have taken
notice of the fame in other countries ; not to multipJy