by Oliver Sacks
From France the wedding party moved by stages to Italy, with experiments along the way: collecting crystals from the rim of Vesuvius; analyzing gas from natural vents in the mountains (it turned out to be, Davy found, identical with marsh gas, or methane); and, for the first time, performing a chemical analysis of paint samples from old masterworks (‘mere atoms,’ he announced).
In Florence, he experimented with burning a diamond under controlled conditions, with a giant magnifying glass. Despite the demonstration of diamond’s inflammability by Lavoisier, Davy had been reluctant, up to this point, to believe that diamond and charcoal were, in fact, one and the same element. It was rather rare for elements to have a number of quite different physical forms (this was before the discovery of red phosphorus, or the allotropes of sulphur). Davy wondered if these might represent different forms of ‘aggregation’ of the atoms themselves, but it was only much later, with the rise of structural chemistry, that this could be defined (the hardness of diamond, it was then shown, was due to the tetrahedral form of its atomic lattices, the softness and greasiness of graphite due to the packing of its hexagonal lattices in parallel sheets).
Davy returned to London after his honeymoon to one of the grandest practical challenges of his lifetime. The Industrial Revolution, now warming up, was devouring ever huger amounts of coal; coal mines were being dug ever deeper, deep enough now to run into the inflammable and poisonous gases of ‘fire-damp’ (methane) and ‘choke-damp’ (carbon dioxide). A canary carried down in a cage could serve as a warning of the presence of asphyxiating choke-damp; but the first indication of fire-damp was, all too often, a fatal explosion. It was desperately important to design a miner’s lamp that could be carried into the lightless depths of the mines without any danger of igniting pockets of fire-damp.
Davy made a crucial observation – that a flame could not pass through a wire mesh or gauze, as long as this were kept cool.«27» He made many different sorts of lamps incorporating this principle, the simplest and most reliable being an oil lamp in which the only way air could get in or out was through screens of wire mesh. The perfected lamps were tried in 1816 and proved not only safe but also, by the appearance of the flame, reliable indicators of fire-damp.
In a further discovery, Davy found that if a platinum wire was put in an explosive mixture, it would become red-hot and glow. He had discovered the miracle of catalysis: how certain substances, such as the platinum metals, might induce a continuing chemical reaction on their surfaces, without being themselves consumed. Thus, for instance, the platinum loop we kept above the kitchen stove would glow when put in the stream of gas, and, becoming red-hot, ignite it. This principle of catalysis was to become indispensable in thousands of industrial processes.«28»
To an extent that I was only to realize later, Humphry Davy and his discoveries were part of our lives, from the electroplated cutlery to the catalytic gas-lighting loop, to photography (which he had been one of the first to perform, making photographs on leather, thirty years or more before others rediscovered the process), to the dazzling arc lamp used to project films in the local cinema. Aluminium, once costlier than gold (Napoleon III, famously, used to give his guests plates of gold, while he himself dined on aluminium), had become cheap and available only with the use of Davyan electrolysis to extract it. And the thousand and one synthetics all around us, from artificial fertilizers to our gleaming bakelite telephones, were all made possible by the magic of catalysis. But, crucially, it was Davy’s personality that appealed to me – not modest, like Scheele, not systematic, like Lavoisier, but filled with the exuberance and enthusiasm of a boy, with a wonderful adventur-ousness and sometimes dangerous impulsiveness – he was always at the point of going too far – and it was this which captured my imagination above all.
CHAPTER TWELVE
Images
Photography had become another passion of mine, and my little lab, already so overfull, often doubled as a darkroom as well. If I try to remember what drew me to photography, I think of the chemicals involved – my hands were often stained with pyrogallol, and seemed to smell of ‘hypo,’ sodium hyposulphite, all the while; of the special lights – the deep ruby safelight; the large flashbulbs stuffed with shiny, crinkly, inflammable metal foil (usually magnesium or aluminium, occasionally zirconium). I think of the optics – the tiny, flattened image of the world on a ground-glass screen; the delight of different f-stops, of focusing, of different lenses; of all the intriguing emulsions one could use – it was, above all, the processes of photography that fascinated me.
But there was also, of course, the sense of being able to make a very personal and perhaps fugitive perception objective and permanent, especially as I lacked the ability to draw or paint. This was fanned, even before the war, by family photo albums, especially those which went back before my birth, to the beach scenes and bathing machines of the 1920s, the street scenes of London at the turn of the century, the stiffly posed grandparents and great-aunts and great-uncles of the 1870s. There were also, most precious of all, a couple of daguerreotypes, in special frames, dating from the 1850s; these had a detail, a finish, that seemed much finer, more brilliant, than those of the later paper prints. My mother particularly cherished one of these, a photo of her mother’s mother, Judith Weiskopf, taken in Leipzig in 1853.
Then there was the whole wide world outside the family, the printed photos in books and newspapers, some of which struck me with great vividness, like the dramatic photos of the Crystal Palace on fire (these confirmed – or did they suggest? – my own very early memories of it) and photos of airships majestically floating (and another of a Zeppelin coming down in flames). I loved photos of distant people and places, most of all the photos in the National Geographic magazine, which would arrive, with its yellow-edged cover, each month. The National Geographic, moreover, had pictures in color, and these affected me especially. I had seen hand-tinted photos – Auntie Birdie was adept at such tinting – but I had never seen actual color photos before. An H.G. Wells tale, ‘The Queer Story of Brownlow’s Newspaper,’ which I read around this time, describes how Brownlow receives one day, instead of his usual 1931 paper, a newspaper dated 1971. What first arouses Mr. Brownlow’s attention, making him realize that he is confronting something incredible, is the fact that this newspaper has photographs in color – something inconceivable to him, living in the 1930s:
Never in all his life had he seen such colour printing – and the buildings and scenery and costumes in the pictures were strange. Strange and yet credible. They were colour photographs of actuality forty years from now.
I sometimes had such a feeling about the color pictures in the National Geographic; they, too, pointed to a brilliant, many-colored world of the future, and away from the monochromes of the past.
But I was more deeply drawn to the photographs of the past, with their dim, delicate sepia tones – they abounded in the older family albums and in the old magazines that I once found piled in the lumber room. I was already, by 1945, very conscious of change, of how prewar life had gone irredeemably, forever. But there were still photos, photos often casually taken, that now possessed a special value, photos of summer holidays before the war, photos of friends and neighbors and relatives, caught in the sunlight of 1935 or 1938, with no shadow or premonition of what would come. It seemed to me wonderful that photographs could capture actual moments, clean cross sections, as it were, of time, fixed forever in silver.
I longed to make photos myself, to document and chronicle scenes, objects, people, places, moments, before they changed or disappeared, swallowed by the transformations of memory and time. I took one such picture of Mapesbury Road, caught in the morning sunlight of July 9, 1945, my twelfth birthday. I wished to document, to hold forever, exactly what confronted me when I opened the curtains that morning. (I still have this photo, two photos, actually, designed to form a stereo pair, as a red and green anaglyph. Now, more than half a century later, it has almost replaced the actual memory,
so that if I close my eyes and try to visualize the Mapesbury Road of my boyhood, all I see is the photograph I took.)
Such documentation was, in part, forced on me by the war, the wholesale way in which seemingly permanent objects were destroyed or removed. There had been wrought iron railings, beautiful and solid, around our front garden before the war, but when I returned home in 1943, they were no longer there. I found this very disturbing, and was even driven to doubt my own memory. Had there in fact been such railings before the war, or had I, in a fanciful or poetic way, somehow invented them? Seeing photos of my younger self, posed against the railings, was a great relief, proving that the railings were really there. And then there was the giant Cricklewood clock, the clock I remembered, or seemed to remember, at least, twenty feet high, with a golden face, in Chichele Road – this, too, was gone in ‘43. There was a similar clock in Willesden Green, and I assumed that I had somehow doubled it in my mind, endowing Cricklewood, my neighborhood, with its twin. Here again, it was a great relief, years later, to see a photo of this clock, to see that I had not invented it (both the iron railings and the clock had been removed as part of the war effort, when the country was desperate for all the iron it could obtain).
It was similar with the vanished Willesden Hippodrome, if indeed it had ever existed. If I even asked, I imagined, people would say, ‘Willesden Hippodrome, indeed! What’s the boy thinking of? As if there would ever have been a hippodrome in Willesden!’ It was only when I saw an old photo that my doubts were banished, and I became confident that there was indeed once such a hippodrome, though it was bombed out of existence during the war.
I read 1984 when it came out in 1949, and found its account of the ‘memory hole’ peculiarly evocative and frightening, for it accorded with my own doubts about my memory. I think that reading this led to an increase in my own journal keeping, and photographing, and an increased need to look at testimonies of the past. This took many forms – an interest in antiquarian books and old things of every sort; in genealogy; in archaeology; and most especially in paleontology. I had been introduced to fossils as a child by Auntie Len, but now I saw them as guarantors of reality.
So I loved old photos of our neighborhood and of London. They seemed to me like an extension of my own memory and identity, helped to moor me, anchor me in space and time, as an English boy born in the 1930s, born into a London similar to that in which my parents, my uncles and aunts, had grown up, a London which would have been recognizable to Wells, Chesterton, Dickens, or Conan Doyle. I pored over old photos, local and historical ones as well as the old family ones, to see where I came from, to see who I was.
If photography was a metaphor for perception and memory and identity, it was equally a model, a microcosm, of science at work – and a particularly sweet science, since it brought chemistry and optics and perception together into a single, indivisible unity. Snapping a picture, sending it out to be developed and printed, was exciting, of course, but in a limited way. I wanted to understand, to master for myself, all the processes involved, and to manipulate them in my own way.
I was especially fascinated by the early history of photography and the chemical discoveries that had led to it: how it was first realized, as early as 1725, that silver salts darkened with light, and how Humphry Davy (with his friend Thomas Wedgwood) had made contact images of leaves and insect wings on paper or white leather soaked in silver nitrate, and photos with a camera lucida. But they were unable to fix the images they produced and could view them only in red light or candlelight, otherwise they would blacken completely. I wondered why Davy, so expert a chemist and so familiar with Scheele’s work, had failed to make use of Scheele’s observation that ammonia could ‘fix’ the images (by removing the surplus silver salt) – had he done so, he might have been seen as the father of photography, anticipating the final breakthrough in the 1830s, when Fox Talbot, Daguerre, and others were able to make permanent images, using chemicals to develop and fix them.
We lived very near my cousin Walter Alexander (it was to his flat we went when a bomb landed next door during the Blitz), and I became close to him despite the great disparity in our ages (though my first cousin, he was thirty years my senior), for he was a professional magician and photographer who retained a very playful character all his life, and loved tricks and illusions of every sort. It was Walter who first inducted me into photography, by showing me the magic of an image emerging as he developed sheets of film in his red-lit darkroom. I never tired of the wonder of this, seeing the first faint hints of an image – were they really there, or was one deceiving oneself? – grow stronger, richer, clearer, come to full life, as he tilted the film to and fro in the tray of developing fluid, until at last, fully developed, there lay a tiny, perfect facsimile of the scene.
Walter’s mother, Rose Landau, had gone to South Africa with her brothers in the 1870s, where she took photographs of mines and miners, taverns and boomtowns, in the early days of the diamond and gold rushes. It had required considerable physical strength, as well as audacity, to make such photographs at this time, for she had to lug a massive camera around with her, along with all the glass plates it might need. Rose was still alive in 1940, the only one of the firstborn uncles and aunts I ever met. Walter himself had her original camera, as well as a considerable collection of cameras and stereoscopes of his own.
In addition to an original Daguerre camera, complete with its iodizing and mercury boxes, Walter had a huge view camera, with a rising front and tilt and bellows, that took eight-by-ten-inch sheet film (he still used this, at times, for studio portraits); a stereo camera; and a beautiful little Leica, with an f⁄3.5 lens – the first 35-millimeter miniature camera I had seen. The Leica was his favorite camera when he went hiking; he preferred to use a twin-lens reflex, a Rolleiflex, for general use. He also had some trick cameras from the beginning of the century – one of these, built for detective work, looked just like a pocket watch, and took pictures on 16-millimeter film.
All my own photography at first was in black and white – I could not have developed and printed my own films, otherwise – but I had no sense that these were ‘lacking’ color. My first camera was a pinhole camera, which gave surprisingly good pictures, with an enormous depth of focus. Then I had a simple fixed-lens box camera – it cost two shillings at Woolworth’s. Then a folding Kodak camera, which took 620 roll film. I was fascinated by the speeds and finenesses of different emulsions, from the slow, fine-grained ones which allowed exquisite detail to the fastest ones, almost fifty times faster than some of the slow emulsions, so that one could take photographs even at night (though these were so grainy one could scarcely enlarge them at all). I looked at some of these different emulsions under the microscope, seeing what the grains of silver actually looked like, and wondered whether one could have grains of silver so small as to produce a virtually grainless emulsion.
I enjoyed making light-sensitive emulsions myself, absurdly crude and slow as they were compared to the ready-made ones. I would take a 10-percent solution of silver nitrate and add it slowly, with continual stirring, to a solution of potassium chloride and gelatin. The crystals suspended in the gelatin were extremely fine and not too light-sensitive, so one could do this safely under a red light. One could make the crystals larger and more sensitive by warming the emulsion for several hours, which would allow the smallest crystals to redissolve and redeposit on the larger ones. After this ‘ripening,’ one added a little more gelatin, let it all set to a stiff jelly, and then smeared it on paper.
I could also impregnate paper directly with silver chloride, avoiding the gelatin altogether, by first immersing the paper in a salt solution and then in silver nitrate; the silver chloride formed would be held by the fibers of the paper. Either way, I was able to make my own print-out paper, as it was called, and with this to make contact prints from negatives, or silhouettes of lace or ferns, though it took several minutes of exposure to direct sunlight to obtain these.
Fixing
the prints with hypo straight after exposure tended to produce rather ugly brown colors, and this drew me into experimenting with toning of various sorts. The simplest was sepia toning – not (alas) done with cuttlefish ink, sepia, as I had hoped, but by converting the silver of the image to sepia-colored silver sulphide. One could do gold toning, too – this involved immersion in a solution of gold chloride, and produced a bluish purple image, metallic gold being precipitated onto the particles of silver. And if one tried this after sulphide toning, one could get a lovely red color, an image of gold sulphide.
I soon spread from this to other forms of toning. Selenium toning gave a rich reddish color, and palladium- and platinum-toned prints had a fine, sober quality, more delicate, it seemed to me, than the usual silver prints. One had to start with a silver image, of course, because only silver salts were sensitive to light, but then one could replace it with almost any other metal. One could easily replace the silver with copper, uranium, or vanadium. A particularly wild combination was to combine a vanadium salt with an iron salt such as ferric oxalate, and then the yellow of the vanadium ferrocyanide and the blue of the ferri-ferrocyanide would combine to form a brilliant green. I enjoyed disconcerting my parents with pictures of green sunsets, green faces, and fire engines or double-decker buses turned green. My photographic manual also described toning with tin, cobalt, nickel, lead, cadmium, tellurium, and molybdenum – but I had to stop myself at this point, for I was becoming obsessed, going overboard with toning, with the possibility of pressing all the metals I knew into use in the darkroom, and forgetting what photography was really for. This sort of too-muchness had no doubt been noticed at school, for it was around this time that I received a school report that said, ‘Sacks will go far, if he does not go too far.’
