Serious medical interest in scurvy coincided with what Burke named the unrolling of the map of mankind, the so-called discovery of the land and the peoples that had lain hidden from Europeans in the portion of the globe known as the Terra Incognita. Journeys of that length did not come cheap. The loss of health and lives—among sailors and indigenes alike—was immense, and scurvy was the chief threat at sea. In the scientific voyages of the 1760s the `experimental gentleman’—naturalists, astronomers, and artists—were themselves, along with the crews, objects of a series of nutritional experiments designed to solve definitively the problem of scurvy. A battery of supplements was supplied, none of which worked. During Cook’s second voyage on the Resolution, J.R. Forster, his son George, William Wales the astronomer and Cook himself were all affected by low vitamin C; it was worse aboard his consort The Adventure. The question I want to ask is this: Why did the failure to discover a cure for scurvy on these and other ships involved in reconnoitering the unknown lands of the South Seas not seriously impede the work of territorial discovery? The answer most often given it alerted the discoverers to the need for fresh food, which certainly helped eliminate the levels of mortality suffered by Magellan and da Gama. But another possibility I want to explore is that scurvy had something in common with experimental techniques insofar as one of its more remarkable symptoms was a morbid receptivity to sense impressions, similar to those that scientists of the Royal Society were trying to excite artificially.
Sudden sounds, such as the report of a musket or a cannon, were well known to kill scorbutic sailors. Even pleasant stimuli such as a drink of fresh water, or a long-awaited taste of fruit, could provoke a seizure and put an end to their lives. In his Omoo, Melville recalls how once `the Trades scarce filled our swooning sails; the air was languid with the aroma of a thousand strange, flowering shrubs. Upon inhaling it, one of the sick who had recently shown symptoms of scurvy, cried out in pain, and was carried below. This is no unusual effect in such cases’ (Melville 1847: 64). When Bernardin de St Pierre landed on Mauritius badly afflicted he was disgusted by the trees, which smelt of excrement, and flowers such as the veloutier were alluring only at a distance, for the odour `quite close is perfectly loathesome’ (1800: 66). Sometimes the sensation passed the frontier from pain to pleasure, or vice versa. Here is Anders Sparrman, another scorbutic naturalist on the Resolution hunting ducks when at last he landed in New Zealand: `The blood from these warm birds which were dying in my hands, running over my fingers, excited me to a degree I had never previously experienced. . . .This filled me with amazement, but the next moment I felt frightened’ (Sparrman in Smith 1956: 138).
The scorbutic eye was particularly engaged, so much so that objects of very incidental importance, such as the colour, shape and even consistency of clouds, could transfix the attention of even a committed utilitarian such as Dampier (`The Sky was at this time covered with small hard Clouds . . . very thick one by another’ [Dampier 1939: 76]). Spectacular novelties such as coral grew more wonderful for Matthew Flinders as scurvy heightened the impression, turning dangerous animate rock into fascinating antiscorbutics: `We had wheat sheaves, mushrooms, stags horns, cabbage leaves, and a variety of other forms, glowing under water with vivid tints of every shade betwixt green, purple, brown, and white’ (Flinders 1814: 2.88). Pleasure and disgust could be aroused by the selfsame phenomenon: Forster was fascinated by the effects of phosphorescence although he believed it was caused by rotting animalcules. 150 years later Stephenson was to have the same mixed reactions to coral.
In the previous century scientists such as Robert Hooke had attempted to construct various prostheses for the sense-organs designed to make the work of discovery more exact: telegraph wires to transport the voice to distant ears, hygroscopes for detecting effluvia leaking from the earth, and of course improved microscopes and telescopes designed to bring the infinitely small and the infinitely distant into distinct focus. Hooke’s reactions to the colours and shapes of microscopic specimens were sometimes quite as ecstatic as Sparrman’s, Flinders’s and Thomas’s, but at the same time he was able to make accurate drawings of them that had never been seen before. In this pursuit he explained how the senses were `wonderfully benefitted . . . and guided to an easie and more exact Performance of their Offices’ (Hooke 1665 : viii). If other people were using ships, huge machines designed to bring the unknown into the purview of the five senses, Hooke was using his own portable contrivances to arrive at what he explicitly referred to as a discovery of `new Worlds and Terra-Incognita’s’ (xvi). His machines were the forerunners of those that accompanied Cook’s supercargoes: Kendal’s and Arnold’s chronometers, Knight’s azimuth compass, and Bird’s astronomical quadrant.
Support for Hooke was by no means unanimous. Margaret Cavendish said his instruments could never penetrate the surface of things and find out the secrets of their constitution; they only disarranged the distances, textures and angles that made them usual or comely, revealing instead the immodesties, moles and hairs that cause the maids of honour in Brobdingnag to appear so repulsive to Gulliver. Were we to see things a thousand times more clearly, or hear things magnified at the same rate, our lives would be made intolerable, Locke argued: there would be no rest, no power of discrimination. Such a witness would live `in a quite different World from other People. Nothing would appear the same to him, and others’ (Locke 1979: 303; [II; xxiii; 12]). For Hooke temporary alienation from the familiar world was the whole point. If a Terra Incognita was to be disclosed, then one had to act in the spirit of foreignness: `An Observer should endeavor to look upon such Experiments and Observations that are more common, and to which he has been more accustom’d, as if they were the greatest Rarity, and to imagine himself a Person of some other Country or Calling, that he never heard of, or seen the like before’ (Hooke 1969: 61-2). Scurvy, you might say, helped the observer into this estranged position.
By opting for the advantages of grossly normal sense impressions, Locke and Cavendish were defending not just the proportionality and communicability of sensations, but also a very specific notion of how they are received and exchanged as ideas. Along with Descartes and Hobbes, Locke agreed that the sensory organ, while being stimulated by an object in the real world, did not take a print of it or in any way incorporate its properties. He said, `There is nothing like our Ideas in the Bodies themselves’ (Locke 1979: 137 [II; vii; 14-15]). The smell of a flower is an event in the sensorium, created purely by the pulsations passing between the olfactory nerve and the brain. Cavendish did not go as far as that, but she resisted the Epicurean doctrine of films and effigies as a streams of matter launched from the surface of the object at the eye, ear, or nose. Using the analogy of the mirror she said, `It is not the real body of the object which the glass presents, but the glass only figures or patterns out the picture presented in and by the glass’ (Cavendish 2001: 51). With this account of representation she denied Lucretius, the arch-empiricist, the indisputable evidence of impressions or any collaboration between them in the production of knowledge, for he had argued that no organ can thwart the receptivity of another. He asked, `Can th’eare, the sight denie?/ Shall th’eare, or tast, the feeling sense oppose?/ Or shall the eie, dispute against the nose?’ (Hutchinson 2012: 1.251; 4.508-10). Cavendish retorted, `The nose knows not what the eyes see’ (Cavendish 2001: 46). For his part, Hooke was convinced of the contrary, for it was only with the help of a microscope that the true roughness of a surface could be felt, a coalition of the prosthetized eye and the imaginary finger: `The roughness and smoothness of a Body is made much more sensible by the help of a Microscope, than by the most tender and delicate Hand’ (Hooke 1667: xii). Walter Charleton, the greatest authority on scurvy and nutrition in the 17th century, noticed that under the pressure of great stimuli the eye will engross the functions of other senses, resulting in the kind of imminent synaesthesia experienced by Dampier when he found clouds hard, and which Addison vouched for in his essays of the pleasures of imagination:
"when he observed that an appetent eye experiences sight as a `more delicate and diffusive Kind of Touch’ (Charleton 1670: 29; Spectator No. 11). Coleridge was fascinated by this phenomenon. He called it the double touch (`touch . . . co-present with vision, yet not coalescing’) and wondered `whether the Skin be not a Terra Incognita in Medicine’" (Notebooks II, 3217, f 70; I, 1826.16.209).
From the beginning of this debate, the issue of enlarged sensations had calqued upon questions of disease. If you could smell too much like Bernardin de St Pierre and Melville’s sailor, or have your eyes dazzle with the colours of serpents, like the Ancient Mariner, then life was not only lived in a foreign place, that place was a hospital. Supposing that it might be possible to sense too much, and out of that superfluity for one organ to seize on the function of another, Francis Hutcheson had concluded such a condition to be inconsistent with providential mercy (`Senses incapable of bearing the surrounding Objects without Pain; Eyes pained with the Light; a Palate offended with the Fruits of the Earth; a Skin as tender as the Coats of the Eye’ [Hutcheson 2002: 119]). But of course what he had done was to reject as improbable the very scenes of scorbutic distress widely reported in contemporary journals. In his Essay on Man Pope similarly excludes a list of morbid susceptibilities as exorbitant to the divine plan, concluding with the figment of a man so tender he shrieks at the smell of a flower, as Melville’s sailor was actually heard to do:
Say what the use, were finer optics given,
T’inspect a mite, not comprehend the heaven?
Or touch, if tremblingly alive all o’er,
To smart and agonise at every pore?
Or quick effluvia darting through the brain,
Die of a rose in aromatic pain?
Approaching the matter of acute sensation from a different angle, Boyle saw a very useful connexion between disease and extraordinary powers of perception. In his essays on effluvia he mentions several examples, some of an innate susceptibility (the lady who swoons at the smell of roses) and some of a valuable acquisition of sensibility made after an illness. A man who recovered from bubonic plague found himself able to smell an infected person before any signs of the pestilence had appeared; another who suffered inflammation of eyes and afterwards could distinguish colours in the dark; a physician who fell sick of a fever and discovered he could now overhear whispered speech at a great distance (Boyle 1999: 7. 268, 282). Boyle’s explanation for these accidental improvements of the subtlety of the senses stems from his belief that effluvia do not bounce off the body, but pierce it and, by affecting its sensory equipment, cause an alteration in the organs of the body that influences subsequent reactions to their environment (7.267). So from a blind and involuntary susceptibility, the body’s organs may advance to an alertness that is active and what Bacon would call ejaculative or emittent. From this superlative awareness of effluvia, Boyle supposes such a degree of potential discrimination that the size, shape, motion and colour of effluvia themselves might become perceptible. So by means of the variations in the internal constitution of the living engine (as Boyle calls the body) he aims at the discovery of an invisible world of particles, just as Hooke with his machines goes in search of a terra incognita in the bottom of a microscope, or Coleridge beneath the porous surface of the skin.
Is scurvy such a disease, capable of prostrating the body and then redeeming it with enhanced perceptions? Walter Charleton and Thomas Willis, Boyle’s contemporaries and authors of books on scurvy, offered some account of how this might happen. For both men the healthy state of the sensitive soul resembled Boyle’s idea of the action and reaction of effluvia. Willis called it dilation or irradiation, Charleton named it corroboration. It occurs when something powerfully imagined actually takes place: `We imagine the Drinking of excellent Wine, with a certain Pleasure, then we indulge it; the Imagination of its Pleasure is again sharpened by the taste, and then by a reflected Appetite drinking is repeated. So as it were in a Circle, the Throat or Appetite provokes the Sensation, and the Sensation causes the Appetite to be sharpened, and iterated' (Willis 1683: 49).
This corroboration of an image by the addition of a sensation is to be compared with the fixations of the scorbutic imagination observed by Thomas Trotter: `The cravings of appetite, not only amuse their waking hours with thoughts on green fields, and streams of pure water; but in their dreams they are tantalized by the favourite idea; and on waking the mortifying disappointment is expressed with the utmost regret, with groans, and weeping, altogether childish’ (Trotter 1792: 44). But then when the desideratum is materialized, what a remarkable shift from miserable privation to intense pleasure! `The patient in the inveterate stage of the disease seems to gather strength even from the sight of fruit: the spirits are exhilarated by the taste itself, and the juice is swallowed, with emotions of the most voluptuous luxury’ (ibid. 141-2). John Mitchel, an Irish political prisoner en route for Tasmania aboard a scorbutic transport, wished never to forget the `brutal rapture’ with which he devoured six oranges when the ship landed in Pernambuco. There is a gentler example of corroboration when the parched Ancient Mariner wakes from a dream of drinking to find his thirst quenched by the rain falling on his bare skin: `Sure I had drunken in my dreams,/ And still my body drank.’
If we bear this in mind when reviewing one of the great junctions in the history of scurvy and science, Humphrey Davy’s tests on nitrous oxide at the Pneumatic Institute in 1799, an unmistakable resemblance seems to take place between the excitements of a scorbutic seaman and the sensations induced by laughing gas in Davy’s fingers, eyes and ears. He made and inhaled the gas in order to test a theory that `azote oxyd,’ as it was called, acted as the source of all contagious diseases including scurvy. While finding that he did not succumb to scurvy or any other malady, Davy did find himself changed in ways a scorbutic sailor or a Royal Scientist might recognize: `I imagined that I had increased sensibility of touch: my fingers were pained by anything rough . . . I was certainly more irritable, and felt more acutely from trifling circumstances . . . My visible impressions were dazzling and apparently magnified . . . when I have breathed it amidst noise, the sense of hearing has been painfully affected even by moderate intensity of sound’ (Davy 1800: 464, 487, 491). At the limit of sensory irritation Davy had discovered that there was no difference between suffering the impression of an object and imagining it. Like Condillac's statue, he could not tell the difference between passivity and activity, `between a cause within, and a cause without' (Condillac 1930: 8). At this pitch both were the same, and the consequence was remarkable, explained by Mike Jay as follows: `[Davy’s] culminating experiment had proved, as nothing ever had before, that an altered sensory and mental frame had the power to generate an entirely different universe’ (Jay: 2010: 199). Was this universe Boyle’s invisible world, or Hooke’s terra incognita, or the corroborative assignation with fresh fruit on a desert island? Probably not, for it was experienced, as Coleridge himself was aware from his experiments with opium and laughing gas, with all sense of `outness’ lost: and then, as he says, `What a horrid disease very moment would become’ (Notebooks 1307.8.56). Scurvy was a terrible affliction but was not that kind of disease. It maintained some link with the real, for no matter how foreign and extravagant it might appear in a dream, it was an authentic message from the body to the imagination to which the imagination did its best to respond. Erasmus Darwin called reveries and delusions resulting in total disobedience to external stimuli `diseases of volition,’ and we can conclude that scurvy was not of that genus because its morbid sensory alertness preserved (no matter obliquely) some kind of faith with the empiricist principles that shadowed its history.