It was ten o'clock ere the more fatigued aboard could muster resolution enough to quit their beds a second time; and then it behooved the minister to prepare for his Sabbath labors ashore. The gale still blew in fierce gusts from the hills, and the rain pattered like small shot on the deck. Loch Scresort, by no means one of our finer island lochs, viewed under any circumstances, looked particularly dismal this morning. It forms the opening of a dreary moorland valley, bounded on one of its sides, to the mouth of the loch, by a homely ridge of Old Red Sandstone, and on the other by a line of dark augitic hills, that attain, at the distance of about a mile from the sea, an elevation of two thousand feet. Along the slopes of the sandstone ridge I could discern, through the haze, numerous green patches, that had once supported a dense population, long since "cleared off" to the backwoods of America, but not one inhabited dwelling; while along a black moory acclivity under the hills on the other side I could see several groups of turf cottages, with here and there a minute speck of raw-looking corn beside them, that, judging from its color, seemed to have but a slight chance of ripening. The hill-tops were lost in cloud and storm; and ever and anon, as a heavier shower came sweeping down on the wind, the intervening hollows closed up their gloomy vistas, and all was fog and rime to the water's edge. Bad as the morning was, however, we could see the people wending their way, in threes and fours, through the dark moor, to the place of worship,—a black turf hovel, like the meeting-house in Eigg. The appearance of the Betsey in the loch had been the gathering signal; and the Free Church islanders,—three-fourths of the entire population—had all come out to meet their minister.
On going ashore, we found the place nearly filled. My friend preached two long energetic discourses, and then returned to the yacht, "a worn and weary man." The studies of the previous day, and the fatigues of the previous night, added to his pulpit duties, had so fairly prostrated his strength, that the sternest teetotaller in the kingdom would scarce have forbidden him a glass of our fifty-year-old Madeira. But even the fifty-year-old Madeira proved no specific in the case. He was suffering under excruciating headache, and had to stretch himself in his bed, with eyes shut but sleepless, waiting till the fit should pass,—every pulse that beat in his temples a throb of pain.
CHAPTER VIII.
Geology of Rum—Its curious Character illustrated—Rum famous for Bloodstones—Red Sandstones—"Scratchings" in the Rocks—A Geological Inscription without a Key—The Lizard—Vitality broken into two—Illustrations—Speculation—Scuir More—Ascent of the Scuir—The Bloodstones—An Illustrative Set of the Gem—M'Culloch's Pebble—A Chemical Problem—The solitary Shepherd's House—Sheep versus Men—The Depopulation of Rum—A Haul of Trout—Rum Mode of catching Trout—At Anchor in the Bay of Glenelg.
The geology of the island of Rum is simple, but curious. Let the reader take, if he can, from twelve to fifteen trap-hills, varying from one thousand to two thousand three hundred feet in height; let him pack them closely and squarely together, like rum-bottles in a case-basket; let him surround them with a frame of Old Red Sandstone, measuring rather more than seven miles on the side, in the way the basket surrounds the bottles; then let him set them down in the sea a dozen miles off the land,—and he shall have produced a second island of Rum, similar in structure to the existing one. In the actual island, however, there is a defect in the inclosing basket of sandstone: the basket, complete on three of its sides, wants the fourth: and the side opposite to the gap which the fourth should have occupied is thicker than the two other sides put together. Where I now write there is an old dark-colored picture on the wall before me. I take off one of the four bars of which the frame is composed,—the end-bar,—and stick it on to the end-bar opposite, and then the picture is fully framed on two of its sides, and doubly framed on a third, but the fourth side lacks framing altogether. And such is the geology of the island of Rum. We find the one loch of the island,—that in which the Betsey lies at anchor,—and the long withdrawing valley, of which the loch is merely a prolongation, occurring in the double sandstone bar: it seems to mark—to return to my illustration—the line in which the superadded piece of frame has been stuck on to the frame proper. The origin of the island is illustrated by its structure: it has left its story legibly written, and we have but to run our eye over the characters and read. An extended sea-bottom, composed of Old Red Sandstone, already tilted up by previous convulsions, so that the strata presented their edges, tier beyond tier, like roofing slate laid aslant on a floor, became a centre of Plutonic activity. The molten trap broke through at various times, and presenting various appearances, but in nearly the same centre; here existing as an augitic rock, there as a syenite, yonder as a basalt or amygdaloid. At one place it uptilted the sandstone; at another it overflowed it; the dark central masses raised their heads above the surface, higher and higher with every earthquake throe from beneath; till at length the gigantic Ben More attained to its present altitude of two thousand three hundred feet over the sea-level, and the sandstone, borne up from beneath like floating sea-wrack on the back of a porpoise, reached in long outside bands its elevation of from six to eight hundred. And such is the piece of history, composed in silent but expressive language, and inscribed in the old geological character, on the rocks of Rum.
The wind lowered and the rain ceased during the night, and the morning of Monday was clear, bracing, and breezy. The island of Rum is chiefly famous among mineralogists for its heliotropes or bloodstones; and we proposed devoting the greater part of the day to an examination of the hill of Scuir More, in which they occur, and which lies on the opposite side of the island, about eight miles from the mooring ground of the Betsey. Ere setting out, however, I found time enough, by rising some two or three hours before breakfast, to explore the Red Sandstones on the southern side of the loch. They lie in this bar of the frame,—to return once more to my old illustration,—as if it had been cut out of a piece of cross-grained deal, in which the annular bands, instead of ranging lengthwise, ran diagonally from side to side; stratum leans over stratum, dipping towards the west at an angle of about thirty degrees; and as in a continuous line of more than seven miles there seem no breaks or repetitions in the strata, the thickness of the deposit must be enormous,—not less, I should suppose, than from six to eight thousand feet. Like the Lower Old Red Sandstones of Cromarty and Moray, the red arenaceous strata occur in thick beds, separated from each other by bands of a grayish-colored stratified clay, on the planes of which I could trace with great distinctness ripple markings; but in vain did I explore their numerous folds for the plates, scales, and fucoid impressions which abound in the gray argillaceous beds of the shores of the Moray and Cromarty Friths. It would, however, be rash to pronounce them non-fossiliferous, after the hasty search of a single morning,—unpardonably so in one who had spent very many mornings in putting to the question the gray stratified beds of Ross and Cromarty, ere he succeeded in extorting from them the secret of their organic riches.
We set out about half-past ten for Scuir More, through the Red Sandstone valley in which Loch Scresort terminates, with one of Mr. Swanson's people, a young active lad of twenty, for our guide. In passing upwards for nearly a mile along the stream that falls into the upper part of the loch, and lays bare the strata, we saw no change in the character of the sandstone. Red arenaceous beds of great thickness alternate with grayish-colored bands, composed of a ripple-marked micaceous slate and a stratified clay. For a depth of full three thousand feet, and I know not how much more,—for I lacked time to trace it further,—the deposit presents no other variety: the thick red bed of at least a hundred yards succeeds the thin gray band of from three to six feet, and is succeeded by a similar gray band in turn. The ripple-marks I found as sharply relieved in some of the folds as if the wavy undulations to which they owed their origin had passed over them within the hour. The comparatively small size of their alternating ridges and furrows give evidence that the waters beneath which they had formed had been of no very profound depth. In the upper part of the valley, which is bare, trackless, and solitary, with a high monotonous sandstone ridge bounding it on the one side, and a line of gloomy trap-hills rising over it on the other, the edges of the strata, where they protrude through the mingled heath and moss, exhibit the mysterious scratchings and polishings now so generally connected with the glacial theory of Agassiz. The scratchings run in nearly the line of the valley, which exhibits no trace of moraines; and they seem to have been produced rather by the operation of those extensively developed causes, whatever their nature, that have at once left their mark on the sides and summits of some of our highest hills, and the rocks and boulders of some of our most extended plains, than by the agency of forces limited to the locality. They testify, Agassiz would perhaps say, not regarding the existence of some local glacier that descended from the higher grounds into the valley, but respecting the existence of the great polar glacier. I felt, however, in this bleak and solitary hollow, with the grooved and polished platforms at my feet, stretching away amid the heath, like flat tombstones in a graveyard, that I had arrived at one geologic inscription to which I still wanted the key. The vesicular structure of the traps on the one hand, identical with that of so many of our modern lavas,—the ripple-markings of the arenaceous beds on the other, indistinguishable from those of the sea-banks on our coasts,—the upturned strata and the overlying trap,—told all their several stories of fire, or wave, or terrible convulsion, and told them simply and clearly; but here was a story not clearly told. It summoned up doubtful, ever-shifting visions,—now of a vast ice continent, abutting on this far isle of the Hebrides from the Pole, and trampling heavily over it,—now of the wild rush of a turbid, mountain-high flood breaking in from the west, and hurling athwart the torn surface, rocks, and stones, and clay,—now of a dreary ocean rising high along the hills, and bearing onward with its winds and currents, huge icebergs, that now brushed the mountain-sides, and now grated along the bottom of the submerged valleys. The inscription on the polished surfaces, with its careless mixture of groove and scratch, is an inscription of very various readings.
We passed along a transverse hollow, and then began to ascend a hill-side, from the ridge of which the water sheds to the opposite shore of the island, and on which we catch our first glimpse of Scuir More, standing up over the sea, like a pyramid shorn of its top. A brown lizard, nearly five inches in length, startled by our approach, ran hurriedly across the path; and our guide, possessed by the general Highland belief that the creature is poisonous, and injures cattle, struck at it with a switch, and cut it in two immediately behind the hinder legs. The upper half, containing all that anatomists regard as the vitals, heart, brain, and viscera, all the main nerves, and all the larger arteries, lay stunned by the blow, as if dead; nor did it manifest any signs of vitality so long as we remained beside it; whereas the lower half, as if the whole life of the animal had retired into it, continued dancing upon the moss for a full minute after, like a young eel scooped out of some stream, and thrown upon the bank; and then lay wriggling and palpitating for about half a minute more. There are few things more inexplicable in the province of the naturalist than the phenomenon of what may be termed divided life,—vitality broken into two, and yet continuing to exist as vitality in both the dissevered pieces. We see in the nobler animals mere glimpses of the phenomenon,—mere indications of it, doubtfully apparent for at most a few minutes. The blood drawn from the human arm by the lancet continues to live in the cup until it has cooled and begun to coagulate; and when head and body have parted company under the guillotine, both exhibit for a brief space such unequivocal signs of life, that the question arose in France during the horrors of the Revolution, whether there might not be some glimmering of consciousness attendant at the same time on the fearfully opening and shutting eyes and mouth of the one, and the beating heart and jerking neck of the other. The lower we descend in the scale of being, the more striking the instances which we receive of this divisibility of the vital principle. I have seen the two halves of the heart of a ray pulsating for a full quarter of an hour after they had been separated from the body and from each other. The blood circulates in the hind leg of a frog for many minutes after the removal of the heart, which meanwhile keeps up an independent motion of its own. Vitality can be so divided in the earthworm, that, as demonstrated by the experiments of Spalanzani, each of the severed parts carries life enough away to set it up as an independent animal; while the polypus, a creature of still more imperfect organization, and with the vivacious principle more equally diffused over it, may be multiplied by its pieces nearly as readily as a gooseberry bush by its slips. It was sufficiently curious, however, to see, in the case of this brown lizard, the least vital half of the creature so much more vivacious, apparently, than the half which contained the heart and brain. It is not improbable, however, that the presence of these organs had only the effect of rendering the upper portion which contained them more capable of being thrown into a state of insensibility. A blow dealt one of the vertebrata on the head at once renders it insensible. It is after this mode the fisherman kills the salmon captured in his wear, and a single blow, when well directed, is always sufficient; but no single blow has the same effect on the earthworm; and here it was vitality in the inferior portion of the reptile,—the earthworm portion of it, if I may so speak,—that refused to participate in the state of syncope into which the vitality of the superior portion had been thrown. The nice and delicate vitality of the brain seems to impart to the whole system in connection with it an aptitude for dying suddenly,—a susceptibility of instant death, which would be wanting without it. The heart of the rabbit continues to beat regularly long after the brain has been removed by careful excision, if respiration be artificially kept up; but if, instead of amputating the head, the brain be crushed in its place by a sudden blow of a hammer, the heart ceases its motion at once. And such seemed to be the principle illustrated here. But why the agonized dancing on the sward of the inferior part of the reptile?—why its after painful writhing and wriggling? The young eel scooped from the stream, whose motions it resembled, is impressed by terror, and can feel pain; was it also impressed by terror, or susceptible of suffering? We see in the case of both exactly the same signs,—the dancing, the writhing, the wriggling; but are we to interpret them after the same manner? In the small red-headed earthworm divided by Spalanzani, that in three months got upper extremities to its lower part, and lower extremities, in as many weeks, to its upper part, the dividing blow must have dealt duplicate feelings,—pain and terror to the portion below, and pain and terror to the portion above,—so far, at least, as a creature so low in the scale was susceptible of these feelings; but are we to hold that the leaping, wriggling tail of the reptile possessed in any degree a similar susceptibility? I can propound the riddle, but who shall resolve it? It may be added, that this brown lizard was the only recent saurian I chanced to see in the Hebrides, and that, though large for its kind, its whole bulk did not nearly equal that of a single vertebral joint of the fossil saurians of Eigg. The reptile, since his deposition from the first place in the scale of creation, has sunk sadly in those parts: the ex-monarch has become a low plebeian.