or leaf of green. But here, in smell, at
least, that ancient mud, swum over by the Diplopterus and the
Diplacanthus, and in which the Coccosteus and Pterichthys burrowed, has
undergone no change. The soft ooze has become solid rock, but its
odoriferous qualities have remained unaltered. I next visited an
excavation a few hundred yards on the upper side of the pump-room, in
which the gray fetid breccia of the Strath has been quarried for
dyke-building, and examined the rock with some degree of care, without,
however, detecting in it a single plate or scale. Lying over that
Conglomerate member of the system which, rising high in the Knock Farril
range, forms the southern boundary of the valley, it occupies the place
of the lower ichthyolitic bed, so rich in organisms in various other
parts of the country; but here the bed, after it had been deposited in
thin horizontal laminae, and had hardened into stone, seems to have been
broken up, by some violent movement, into minute sharp-edged fragments,
that, without wear or attrition, were again consolidated into the
breccia which it now forms. And its ichthyolites, if not previously
absorbed, were probably destroyed in the convulsion. Detached scales and
spines, however, if carefully sought for in the various openings of the
valley, might still be found in the original laminae of the fragments.
They must have been amazingly abundant in it once; for so largely
saturated is the rock with the organic matter into which they have been
resolved, that, when struck by the hammer, the impalpable dust set loose
sensibly affects the organs of taste, and appeals very strongly to those
of smell. It is through this saturated rock that the mineral springs
take their course. Even the surface-waters of the valley, as they pass
over it contract in a perceptible degree its peculiar taste and odor.
With a little more time to spare, I would fain have made this breccia of
the Old Red the subject of a few simple experiments. I would have ground
it into powder, and tried upon it the effect both of cold and hot
infusion. Portions of the water are sometimes carried in casks and
bottles, for the use of invalids, to a considerable distance; but it is
quite possible that a little of the _rock_, to which the water owes its
qualities, might, when treated in this way, have all the effects of a
considerable quantity of the _spring_. It might be of some interest,
too, to ascertain its qualities when crushed, as a