by John Carey
Obtaining gastric juice in this manner, Beaumont was able to answer a question that had puzzled medical science – namely, how the stomach digests. Previous accounts had suggested that the stomach worked like a fermenting vat or a mill or a cooking vessel. Beaumont showed that gastric juice, placed in a glass vessel, would dissolve foodstuffs at just the same rate and in just the same way as they were dissolved inside St Martin’s stomach. He deduced that gastric juice was a chemical agent, and he rightly identified its important acid component as hydrochloric (which he calls ‘muriatic’):
I think I am warranted, from the result of all the experiments, in saying, that the gastric juice, so far from being ‘inert as water,’ as some authors assert, is the most general solvent in nature, of alimentary matter – even the hardest bone cannot withstand its action. It is capable, even out of the stomach, of effecting perfect digestion, with the aid of due and uniform degrees of heat (100° Fahrenheit), and gentle agitation … We must, I think, regard this fluid as a chemical agent, and its operation as a chemical action. It is certainly every way analogous to it; and I can see no more objection to accounting for the change effected on the food, on the supposition of a chemical process, than I do in accounting for the various and diversified modifications of matter, which are operated on in the same way. The decay of the dead body is a chemical operation, separating it into its elementary principles – and why not the solution of aliment in the stomach …
Pure gastric juice, when taken directly out of the stomach of a healthy adult, unmixed with any other fluid, save a portion of the mucus of the stomach, with which it is most commonly, and perhaps always combined, is a clear, transparent fluid; inodorous; a little saltish; and very perceptibly acid. Its taste, when applied to the tongue, is similar to thin mucilaginous water, slightly acidulated with muriatic acid. It is readily diffusible in water, wine or spirits; slightly effervesces with alkalis; and is an effectual solvent of the materia alimentaria [food]. It possesses the property of coagulating albumen, in an eminent degree; is powerfully antiseptic, checking the putrefaction of meat; and effectually restorative of healthy action, when applied to old, fœtid sores, and foul, ulcerating surfaces.
Beaumont’s publication of his findings in 1833 made him famous throughout the medical world.
Source: William Beaumont, Experiments and Observations on the Gastric Juice and the Physiology of Digestion, Burlington, Chauncey Goodrich, 1833.
Those Dreadful Hammers: Lyell and the New Geology
Geology revolutionized thought and feeling in the early nineteenth century. Its effects spread far beyond the scientific community, destroying established truths, and forcing ordinary men and women to realize that they, and everything they thought of as time and history, were a mere blip in the unimaginable millions of years of the earth’s existence. Faced with these mind-blanking immensities, many found their religious faith ebbing away. Orthodox, Bible-based estimates of the earth’s age, such as that of Archbishop Ussher (who fixed the date of the creation of the world as 23 October 4004 BC), now seemed ridiculously inadequate. ‘If only the Geologists would let me alone, I could do very well,’ lamented John Ruskin in 1851, ‘but those dreadful Hammers! I hear the clink of them at the end of every cadence of the Bible verses.’
The manifesto of the new science was Charles Lyell’s Principles of Geology (1830–3). What this book set out to shatter was the assumption that the earth – its oceans, land masses, and geological strata – had remained much the same since the Creation, or since an age of vast volcanic upheavals which, it was imagined, had taken place very early in its history. Lyell argued that, on the contrary, the surface of the earth is continuously changing. The agents that have changed it in the past are still active today though since they work very slowly we tend to overlook them. They are essentially two – water (rivers, tides, etc.) and subterranean fire (causing earthquakes and volcanoes). They work in opposite ways – water wearing down, and subterranean fire elevating the earth’s surface:
We know that one earthquake may raise the coast of Chile for a hundred miles to an average height of about five feet. A repetition of two thousand shocks of equal violence might produce a mountain chain one hundred miles long and ten thousand feet high. Now should … one of these conclusions happen in a century, it would be consistent with the order of events experienced by the Chileans from the earliest times.
On this reckoning 200,000 years – a brief period in geological time – could produce a mountain range where flat land, or sea, had been before. It is this agency, Lyell argued, that has created the continents:
There is scarcely any land hitherto examined in Europe, North Asia, or North America, which has not been raised from the bosom of the deep, since the origins of the carboniferous rocks … If we were to submerge again all the marine strata [i.e. rock layers containing underwater remains], from the transition limestone to the most recent shelly beds, the summits of some primary mountains would alone remain above the waters.
Great as such a change might seem to us it is, Lyell points out, quite normal in geological terms.
However constant we believe the relative proportion of sea and land to continue, we know that there is annually some small variation in their respective geographical positions, and that in every century the land is in some parts raised, and in others depressed by earthquakes, and so likewise is the bed of the sea. By these and other ceaseless changes, the configuration of the earth’s surface has been remodelled again and again since it was the habitation of organic beings, and the bed of the ocean has been lifted up to the height of some of the loftiest mountains. The imagination is apt to take alarm, when called upon to admit the formation of such irregularities of the crust of the earth, after it had become the habitation of living creatures; but if time be allowed, the operation need not subvert the ordinary repose of nature, and the result is insignificant, if we consider how slightly the highest mountain chains cause our globe to differ from a perfect sphere. Chimborazo [a mountain in Ecuador], although it rises to more than 21,000 feet above the surface of the sea, would only be represented on an artificial globe, of about six feet in diameter, by a grain of sand less than one-twentieth of an inch in thickness. The superficial inequalities of the earth, then, may be deemed minute in quantity, and their distribution at any particular epoch must be regarded in geology as temporary peculiarities.
Rivers, carrying and depositing silt, are also, Lyell points out, working perpetually to change the configuration of land and sea, sometimes at an astonishing rate.
One of the most extraordinary statements is that of Major Rennell, in his excellent paper on the Delta of the Ganges. ‘A glass of water’, he says, ‘taken out of the river when at its height, yields about one part in four of mud. No wonder, then, that the subsiding waters should quickly form a stratum of earth, or that the delta should encroach on the sea!’ The same hydrographer computed with much care the number of cubic feet of water discharged by the Ganges into the sea, and estimated the mean quantity through the whole year to be eighty thousand cubic feet in a second. When the river is most swollen, and its velocity much accelerated, the quantity is four hundred and five thousand cubic feet in a second… We are somewhat staggered by the results to which we must arrive if we compare the proportion of mud, as given by Rennell, with his computation of the quantity of water discharged, which latter is probably very correct. If it were true that the Ganges, in the flood season, contained one part in four of mud, we should then be obliged to suppose that there passes down, every four days, a quantity of mud equal in volume to the water which is discharged in the course of twenty-four hours. If the mud be assumed to be equal to one-half the specific gravity of granite (it would, however, be more), the weight of matter daily carried down in the flood season, would be about equal to seventy-four times the weight of the Great Pyramid of Egypt. Even if it could be proved that the turbid waters of the Ganges contain one part in a hundred of mud, which is affirmed to be the case in regard to t
he Rhine, we should be brought to the extraordinary conclusion that there passes down, in every two days, into the Bay of Bengal, a mass about equal in weight and bulk to the Great Pyramid … We may confidently affirm that when the aggregate amount of solid matter transported by rivers in a given number of centuries from a large continent, shall be reduced to arithmetical computation, the result will appear most astonishing to those who are not in the habit of reflecting how many of the mightiest operations in nature are effected insensibly, without noise or disorder.
In later editions of the Principles Lyell modified his estimate of mud in the Ganges – but this did not affect his main argument.
Since we normally see only what is happening on the surface of the earth, we are, he stresses, badly placed as geological observers. We do not see new strata – such as Ganges mud – being laid down on the ocean floor. Nor can our eyes penetrate to the subterranean rivers and reservoirs of liquid rock far beneath the earth’s surface. Hence we tend to assume that rocks such as granite are older than the ‘sedimentary’ rocks, composed of underwater deposits, and belong to some ‘primeval’ state of nature. Lyell’s argument, however, is that granite, and other ‘primeval’ rocks, are constantly being formed out of sedimentary rocks by subterranean fire, and if we lived in the depths of the earth we should assume that they were the new rocks and the sedimentary ones the old.
If we may be allowed so far to indulge the imagination, as to suppose a being entirely confined to the nether world – some ‘dusky melancholy sprite’, like Umbriel [a gnome in Alexander Pope’s poem The Rape of the Lock], who could ‘flit on sooty pinions to the central earth’, but who was never permitted to ‘sully the fair face of light’ and emerge into the regions of water and air; and if this being should busy himself in investigating the structure of the globe, he might frame theories the exact converse of those adopted by human philosophers. He might infer that the stratified rocks, containing shells and other organic remains, were the oldest of created things, belonging to some original and nascent state of the planet. ‘Of these masses’, he might say, ‘whether they consist of loose, incoherent sand, soft clay, or solid rock, none have been formed in modern times. Every year some parts of them are broken and shattered by earthquakes, or melted up by volcanic fire; and when they cool down slowly from a state of fusion, they assume a crystalline form perfectly distinct from those inexplicable rocks which are so regularly bedded, and contain stones full of curious impressions and fantastic markings. This process cannot have been carried on for an indefinite time, for in that case all the stratified rocks would ere this have been fused and crystallised. It is therefore probable that the whole planet once consisted of these curiously-bedded formations, at a time when the volcanic fire had not yet been brought into activity. Since that period there seems to have been a gradual development of heat, and this augmentation we may expect to continue till the whole globe shall be in a state of fluidity and incandescence.’
Such might be the system of the Gnome at the very same time that the followers of Leibnitz [1646–1716, a German philosopher], reasoning on what they saw on the outer surface, would be teaching the doctrine of gradual refrigeration, and averring that the earth had begun its career as a fiery comet, and would hereafter become an icy mass … Man observes the annual decomposition of crystalline and igneous rocks, and may sometimes see their conversion into stratified deposits; but he cannot witness the reconversion of the sedimentary into the crystalline by subterranean fire. He is in the habit of regarding all the sedimentary rocks as more recent than the unstratified, for the same reason that we may suppose him to fall into the opposite error if he saw the origin of the igneous class only.
Of the many instances Lyell gives of the immense periods of time needful for geological processes, none is more striking than his comment on the rocks known as marls, which were produced as sediments on the floors of freshwater lakes during the Eocene period (which extended from about 54 million to about 38 million years ago).
The entire thickness of these marls is unknown, but it certainly exceeds, in some places, 700 feet. They are for the most part either light-green or white, and usually calcareous. They are thinly foliated, a character which frequently arises from the innumerable thin plates or scales of that small animal called cypris, a genus which comprises several species, of which some are recent, and may be seen swimming rapidly through the waters of our stagnant pools and ditches. This animal resides within two small valves like those of a bivalve shell, and it moults its integuments annually … Countless myriads of the shells of cypris were shed in the Eocene lakes, so as to give rise to divisions in the marl as thin as paper, and that too in stratified masses several hundred feet thick. A more convincing proof … of the slow and gradual process by which the lake was filled up with fine mud cannot be desired.
But the most dramatic implications of Lyell’s theory relate to the future not the past. The perpetual interchange of sea and land on the earth’s surface must, he predicts, go on, since the agents that caused it are still in operation. The northern hemisphere was once a vast ocean, dotted with islands, like the archipelagoes of the South Pacific, and it will return to this state again.
The existence of enormous seas of fresh water, such as the North American lakes, the largest of which is elevated more than six hundred feet above the level of the ocean, and is in parts twelve hundred feet deep, is alone sufficient to assure us, that the time will come, however distant, when a deluge will lay waste a considerable part of the American continent … Notwithstanding, therefore, that we have not witnessed within the last three thousand years the devastation by deluge of a large continent, yet, as we may predict the future occurrence of such catastrophes, we are authorized to regard them as part of the present order of Nature.
Redistribution of the land masses will, Lyell points out, cause radical changes in climate. Ages of intense heat and cold will succeed each other in the future, as they have in the past – the summers and winters of the geological ‘great year’. As the climate of our hemisphere changes, so will its vegetation, and the animal life it supports.
Then might those genera of animals return, of which the memorials are preserved in the ancient rocks of our continents. The huge iguanodon might reappear in the woods, and the icthyosaur in the sea, while the pterodactyl might flit again through umbrageous groves of tree ferns. Coral reefs might be prolonged beyond the arctic circle, where the whale and the narwal now abound. Turtles might deposit eggs in the sand of the sea beach, where now the walrus sleeps, and where the seal is drifted on the ice-floe.
When the poet Alfred Tennyson read Lyell’s Principles, he felt, like many Victorians, dismay. Lyell’s demonstration of the temporariness of the familiar world shocked him. In his great poem In Memoriam, the classic expression of Victorian angst, he keeps Lyell’s book in mind. Simple geological observation had allowed Lyell to assert that:
Millions of our race are now supported by lands situated where deep seas once prevailed in earlier ages. In many districts not yet occupied by man, land animals and forests now abound where the anchor once sank into the oozy bottom.
In Tennyson, this becomes:
There rolls the deep where grew the tree.
O earth, what changes hast thou seen!
There where the long street roars, hath been
The stillness of the central sea.
The hills are shadows, and they flow
From form to form, and nothing stands;
They melt like mist, the solid lands,
Like clouds they shape themselves and go.
Equally appalling was Lyell’s assurance that:
Amidst the vicissitudes of the earth’s surface, species cannot be immortal, but must perish, one after the other, like the individuals which compose them. There is no possibility of escaping from this conclusion.
This wrung an anguished cry from Tennyson:
Are God and Nature then at strife
That Nature lends such evil
dreams?
So careful of the type she seems,
So careless of the single life …
‘So careful of the type?’ but no
From scarped cliff and quarried stone
She cries, ‘A thousand types are gone:
I care for nothing, all shall go.’
Lyell’s own response was calmer and more chilling. He foresaw not merely the extinction of the human race, but the gradual obliteration of every single trace of its existence.
We may anticipate with confidence that many edifices and implements of human workmanship, and the skeletons of men, and casts of the human form, will continue to exist when the great part of the present mountains, continents, and seas have disappeared. Assuming the future duration of the planet to be indefinitely protracted, we can foresee no limit to the perpetuation of some of the memorials of man, which are continually entombed in the bowels of the earth or in the bed of the ocean, unless we carry forward our views to a period sufficient to allow the various causes of change, both igneous and aqueous, to remodel more than once the entire crust of the earth. One complete revolution will be inadequate to efface every monument of our existence … Yet it is no less true that none of the works of a mortal can be eternal … Even when they have been included in rocky strata, when they have been made to enter as it were into the solid framework of the globe itself, they must nevertheless eventually perish; for every year some portion of the earth’s crust is shattered by earthquakes or melted by volcanic fire, or ground to dust by the moving waters on the surface.