by Oliver Sacks
There was an oddly massive, chunky camera in Walter’s collection – this, he said, was a color camera: it had two half-silvered mirrors in it, dividing the incoming light into three beams, and these were directed through differently colored filters to three separate plates. Walter’s color camera was a direct descendant of a famous experiment done at the Royal Institution by Clerk Maxwell in 1861, photographing a colored bow with ordinary black-and-white plates through filters of the three primary colors – red, green, and violet – and projecting the black-and-white positives of these images using three lanterns with corresponding filters. When they were all perfectly superimposed, the three black-and-white pictures exploded into full color. With this, Maxwell showed that every color visible to the human eye could be constructed from just these three ‘primary’ colors, because the eye itself had three equivalently ‘tuned’ color receptors, rather than an infinity of color receptors for every conceivable hue and wavelength.
While Walter once demonstrated this to me with three lanterns, I was eager to have this miracle, this sudden explosion of color, more immediately to hand. The most exciting way of getting instant color was by a process called Finlaycolor, in which, in effect, three color-separation negatives were taken simultaneously by using a grid ruled with microscopic red, green, and violet lines. One then made a positive, a lantern slide, from this negative, and brought it into exact alignment with the grid. This was tricky, delicate, but when one had them in perfect register, the previously black-and-white slide would burst into full color. Since the screen, with its microscopic lines, simply appeared grey, one saw, when it was juxtaposed with the slide, the most magical, unexpected creation of color, where seemingly there had been none before. (The National Geographic originally used Finlaycolor, and one could see the fine lines on these if one looked with a magnifying glass.)
To make color prints, one had to print three positive images in the complementary colors – cyan, magenta, and yellow – and then superimpose them. Though there was a film, Kodachrome, that did this automatically, I preferred to do it in the old, delectable way, making separate cyan, magenta, and yellow diapositives from my separation negatives and then floating them gently, one above the other, until I had them in exact superposition. With this, suddenly, marvelously, the colors of the original burst out, having been coded, as it were, in the three monochromes.
I fiddled with these color separations endlessly, seeing the effect of juxtaposing two rather than three colors, or viewing the slides through the wrong filters. These experiments were at once amusing and instructive; they allowed me to create a range of strange color distortions, but above all they taught me to admire the elegance and economy with which the eye and brain worked, and which one could simulate remarkably well with a photographic three-color process.
We also had at the house hundreds of stereoscopic ‘views’ – many on cardboard rectangles, others on glass plates – paired, faded sepia photos of Alpine scenery, the Eiffel Tower, Munich in the 1870s (my mother’s mother was born in Gunzenhausen, a little village some miles from Munich), Victorian beach and street scenes, and industrial scenes of various sorts (one particularly arresting view was of a Victorian factory, with long treadles driven by steam engines, and it was this image that came to my mind when I read about Coketown in Hard Times ). I loved feeding these double photographs into the big stereoscope in the drawing room – a massive wooden instrument that stood on its own stand and had brass knobs for focusing and altering the separation of the lenses. Such stereoscopes were still quite common, though no longer as universal as they had been at the turn of the century. Seeing the flat, dim photographs suddenly acquire a new dimension, a real and intensely visible depth, gave them a special reality, a verisimilitude of a peculiar and private sort. There was a romantic, secret quality to the stereo views, for one was privy to a sort of frozen theater when one looked through the eyepieces – a theater entirely one’s own. I felt I could almost enter into them, like the dioramas in the museum.
There was, in these views, a small but crucial difference of parallax or perspective between the two pictures, and it was this which created the sense of depth. One had no sense of what each eye saw separately, for the two views coalesced, magically, to form a single coherent view.
The fact that depth was a construction, a ‘fiction’ of the brain, meant that one could have deceptions, illusions, tricks of various sorts. I never had a stereo camera myself, but would take two pictures in succession, moving the camera a couple of inches between exposures. If one moved the camera more than this, the parallactic differences were exaggerated, and the two pictures, when fused, gave an exaggerated sense of depth. I made a hyper-stereoscope, using a cardboard tube with mirrors set obliquely inside it, increasing the interocular distance, in effect, to two feet or more. This was marvelous for bringing out the different depths of distant buildings or hills, but yielded bizarre effects at close distances – a Pinocchio effect, for example, when one looked at people’s faces, for their noses seemed to be sticking out inches in front of them.
It was also intriguing to reverse the pictures. One could easily do this with stereo photographs, but one could also do it by making a pseudoscope, with a short cardboard tube and mirrors, so that the apparent position of the eyes was reversed. This caused distant objects to look closer than nearby ones – a face, for instance, might look like a concave mask. But it produced an interesting rivalry or contradiction, for one’s knowledge, and every other visual cue, might be saying one thing, and the pseudoscopic images saying another, and one would see first one thing then another, as the brain alternated between different perceptual hypotheses.«29»
The other side to all of this, I came to realize – a sort of deconstruction or decomposition – could occur when I had migraines, in which there were often strange visual alterations. My sense of color might be briefly lost or altered; objects might look flat, like cutouts; or instead of seeing movement normally, I might see a series of flickering stills, as when Walter ran his film projector too slow. I might lose half of my visual field, with objects missing to one side, or faces bisected. I was terrified when I first got attacks like this – they started when I was four or five, before the war – but when I told my mother about them, she said she had similar attacks, and that they did no harm and lasted only a few minutes. With this, I started to look forward to my occasional attacks, wondering what might happen in the next one (no two were quite the same), what the brain, in its ingenuity, might be up to. Migraines and photography, between them, may have helped to tilt me in the direction in which, years later, I would go.
My brother Michael was fond of H.G. Wells, and lent me his copy of The First Men in the Moon at Braefield. It was a small book, bound in blue morocco leather, and its illustrations impressed me as much as the text – the attenuated Selenites, walking in single file, and the Grand Lunar, with his distended brain case, in his luminous, fungus-lit cavern on the moon. I loved the optimism and excitement of the journey to space, and the idea of a material (‘cavorite’) impermeable to gravity. One of the chapters was called ‘Mr. Bedford in Infinite Space,’ and I loved the notion of Mr. Bedford and Mr. Cavor in their little sphere (it resembled Beebe’s bathysphere, which I had seen pictures of), snapping the cavorite shutters open and closed, shutting off the earth’s gravity. The Selenites, the moon people, were the first aliens I had ever read about, and after this I sometimes met them in my dreams. But there was sadness, too, because Cavor in the end is marooned on the moon, with only the inhuman, insectile Selenites for company, in unutterable loneliness and solitude.
After Braefield, The War of the Worlds became a favorite too, not least because the Martian fighting machines generated an exceedingly dense, inky vapor (‘it sank down through the air and poured over the ground in a manner rather liquid than gaseous’) that contained an unknown element, combined with the gas argon – and I knew that argon, an inert gas, could not be compounded by any earthly means.«30»
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p; I was very fond of bicycling, especially on country roads through the little towns and villages around London, and reading The War of the Worlds, I decided to trace the advance of the Martians, starting on Horsell Common, where the first Martian cylinder landed.
Wells’s descriptions seemed so real to me that by the time I reached Woking, I found it surprisingly intact, considering how it had been devastated by the Martian heat ray in ‘98. And I was startled, in the little village of Shepperton, at finding the church steeple still standing, for I had accepted, almost as historical fact, that it had been knocked down by a reeling Martian tripod. And I could not go to the Natural History Museum without thinking of ‘the magnificent, and almost complete specimen [of a Martian] in spirits’ which Wells assured us was there. (I would find myself looking for this in the cephalopod gallery, as all the Martians seemed to be somewhat octopoid in nature.)
It was similar with the Natural History Museum itself – its ruined, cobwebbed galleries open to the air – which Wells’s Time Traveller wanders through in A.D. 800,000. I could never go to the museum thereafter without seeing its desolate future form superimposed on the present, like the memory of a dream. Indeed, the pedestrian reality of London itself became transformed for me by the charged and mythical London of Wells’s short stories, with places that could only be seen in certain moods or states – the door in the wall, the magic shop.
I found the later, ‘social’ Wells novels of little interest as a boy, preferring the earlier tales, which combined remarkable science-fiction extrapolations with an intense, poetic sense of human frailty and mortality, as with the Invisible Man, so arrogant at first, who dies so pitifully, or the Faustian Dr. Moreau, who is finally killed by his own creations.
But his stories were also full of ordinary people who have extraordinary visual experiences of every sort: the little shopkeeper who is granted ecstatic visions of Mars through gazing into a mysterious crystal egg; or the young man whose eyes are given a sudden twist as he stands between the poles of an electromagnet in a storm, transporting him visually to an uninhabited rock near the South Pole. I was addicted to Wells’s stories, his fables, as a boy (and many are still resonant for me fifty years later). The fact that he was still alive in 1946, still with us, after the war, made me long urgently, improperly, to see him. And having heard that he lived in a little terrace of houses, Hanover Terrace, off Regent’s Park, I would sometimes go there after school, or on weekends, hoping to catch a glimpse of the old man.
CHAPTER THIRTEEN
Mr. Dalton’s Round Bits of Wood
Experimenting in my lab brought home to me that chemical mixtures were completely unlike chemical compounds. One could mix salt and sugar, say, in any proportion. One could mix salt and water – the salt would dissolve, but then one could evaporate it and recover the salt unchanged. Or one could take a brass alloy and recover its copper and zinc unchanged. When one of my dental fillings came out, I was able to distill off its mercury, unchanged. All of these – solutions, alloys, amalgams – were mixtures. Mixtures, basically, had the properties of their ingredients (plus one or two ‘special’ qualities perhaps – the relative hardness of brass, for example, or the lowered freezing point of salt water). But compounds had utterly new properties of their own.
It was tacitly accepted by most chemists in the eighteenth century that compounds had fixed compositions and the elements in them would combine in precise, invariable proportions – practical chemistry could hardly have proceeded otherwise. But there had been no explicit investigations of this, or declarations on the matter, until Joseph-Louis Proust, a French chemist working in Spain, embarked on a series of meticulous analyses comparing various oxides and sulphides from around the world. He was soon convinced that all genuine chemical compounds did indeed have fixed compositions – and that this was so however the compound was made, or wherever it was found. Red mercuric sulphide, for instance, always had the same proportions of mercury and sulphur, whether it was made in the lab or found as a mineral.«31»
Between pole and pole [Proust wrote] compounds are identical in composition. Their appearance may vary owing to their mode of aggregation, but their properties never…The cinnabar of Japan has the same composition as the cinnabar of Spain; silver chloride is identically the same whether obtained from Peru or from Siberia; in all the world there is but one sodium chloride; one saltpetre; one calcium sulphate; and one barium sulphate. Analysis confirms these facts at every step.
By 1799, Proust had generalized his theory into a law – the law of fixed proportions. Proust’s analyses, and his mysterious law, excited attention among chemists everywhere, not least in England, where they were to inspire profound insights in the mind of John Dalton, a modest Quaker schoolteacher in Manchester.
Gifted in mathematics, and drawn to Newton and his ‘corpuscular philosophy’ from an early age, Dalton had sought to understand the physical properties of gases – the pressures they exerted, their diffusion and solution – in corpuscular or ‘atomic’ terms. Thus he was already thinking of ‘ultimate particles’ and their weights, albeit in this purely physical context, when he first heard of Proust’s work, and by a sudden intuitive leap, saw how these ultimate particles might account for Proust’s law, and indeed the whole of chemistry.
For Newton and Boyle, though there were different forms of matter, the corpuscles or atoms of which they were composed were all identical. (Thus there was always, for them, the alchemical possibility of turning a base metal into gold, for this only entailed change of form, a transformation of the same basic matter.)«32 »But now the concept of elements, thanks to Lavoisier, was clear, and for Dalton there were as many kinds of atoms as there were elements. Every one had a fixed and characteristic ‘atomic weight,’ and this was what determined the relative proportions in which it combined with other elements. Thus if 23 grams of sodium invariably combined with 35.5 grams of chlorine, this was because sodium and chlorine atoms had atomic weights of 23 and 35.5. (These atomic weights were not, of course, the actual weights of atoms, but their weights relative to that of a standard – for example, that of a hydrogen atom.)
Reading Dalton, reading about atoms, put me in a sort of rapture, thinking that the mysterious proportionalities and numbers one saw on a gross scale in the lab might reflect an invisible, infinitesimal, inner world of atoms, dancing, touching, attracting, and combining. I had the sense that I was being enabled to see, using the imagination as a microscope, a tiny world, an ultimate world, billions or trillions of times smaller than our own – the actual constituents of matter.
Uncle Dave had shown me gold leaf, beaten and hammered out until it became almost transparent, so that it transmitted light, a beautiful bluish green light. This leaf, a millionth of an inch thick, he said, was only a few dozen atoms thick. My father had shown me how a very bitter substance such as strychnine could be diluted a millionfold and still be tasted. And I liked to experiment with thin films, to blow soap bubbles in the bath – a speck of soapy water could be blown, with care, into a huge bubble – and to watch oil, in iridescent films, spreading on wet roads. All these prepared me, in a way, to imagine the very small – the smallness of particles that composed the millionth-of-an-inch thickness of gold leaf, a soap bubble, or an oil film.
But what Dalton intimated was infinitely more thrilling: for it was not just atoms in the Newtonian sense, but atoms as richly individual as the elements themselves – atoms whose individuality gave elements theirs.
Dalton later made wooden models of atoms, and I saw his actual models in the Science Museum as a boy. These, crude and diagrammatic as they were, excited my imagination, helped give me a sense that atoms really existed. But not everyone felt this, and, for some chemists, Dalton’s models epitomized the absurdity, as they saw it, of an atomic hypothesis. ‘Atoms,’ the eminent chemist H.E. Roscoe was to write, eighty years later, ‘are round bits of wood invented by Mr. Dalton.’
It was indeed possible, in Dalton’s time, to regard t
he idea of atoms as implausible, if not outright nonsense, and it would be over a century before indisputable evidence for the existence of atoms was secured. Wilhelm Ostwald, for one, was not convinced of the reality of atoms, and in his 1902 Principles of Inorganic Chemistry he wrote:
Chemical processes occur in such a way as if the substances were composed of atoms…At best there follows from this the possibility that they are in reality so: not however, the certainty…One must not be led astray by the agreement between picture and reality, and confound the two…An hypothesis is only an aid to representation.
Now, of course, we can ‘see’ and even manipulate individual atoms, using an atomic force microscope. But it required enormous vision and courage, at the very beginning of the nineteenth century, to postulate entities so utterly beyond the bounds of any empirical demonstration possible at the time.«33»
Dalton’s theory of chemical atoms was detailed in his notebook on the 6th of September, 1803, his thirty-seventh birthday. He was at first too modest or too diffident to publish anything on his theory (he had, however, worked out the atomic weights of half a dozen elements – hydrogen, nitrogen, carbon, oxygen, phosphorus, sulphur – which he recorded in his notebook). But word was soon out that he had hatched something astonishing, and Thomas Thomson, the eminent chemist, went up to Manchester to meet him. A single short conversation with Dalton in 1804 ‘converted’ Thomson, altered his life. ‘I was enchanted,’ he later wrote, ‘with the new light which immediately burst upon my mind, and I saw at a glance the immense importance of such a theory.’