Great Breakthroughs in Darkness


Authorized by

Chief Secretary of the Ministry of
Photographic Arcana, Correspondent of No
Few Academies, Devoted Husband, &c.

“Alas! That this speculation is somewhat too refined to be introduced into a modern novel or romance; for what a denouement we should have, if we could suppose the secrets of the darkened chamber to be revealed by the testimony of the imprinted paper!”

— William Henry Fox Talbot


(c. 1820 – October 12, 1888)

Inventor of the praxiscope technology (which see), Professor Aanschultz believed that close observation of physiology and similar superficial phenomena could lead to direct revelation of the inner or secret processes of nature. Apparent proof of this now discredited theory was offered by his psychopraxiscope, which purported to offer instantaneous viewing of any subject’s thoughts. (Later researchers demonstrated that the device “functioned” by creating interference patterns in the inner eye of the observer, triggering phosphene splash and lucid dreaming.) Aanschultz’s theories collapsed, and the Professor himself died in a Parisian lunatic asylum, after his notorious macropraxiscope failed to extract any particular meaning from the contours of the Belgian countryside near Waterloo. Some say he was already unstable from abuse of his autopsychopraxiscope, thought to be particularly dangerous because of autophagous feedback patterns generated in its operator’s brain. However, there is evidence that Aanschultz was quite mad already, owing to the trauma of an earlier research disaster.


The key lens used in Aanschultz’s notorious psychopraxiscope, designed to capture and focus abaxial rays reflecting from a subject’s eye.


A skylight or aperture for admitting light to a studio, or an arrangement for securing the same end by reflection. In the days when studios for portraiture were generally found at the tops of buildings not originally erected for that purpose, and perhaps in narrow thoroughfares or with a high obstruction adjacent, I found myself climbing a narrow, ill-lit flight of stairs, away from the sound of wagon wheels rattling on cobblestones, the common foetor of a busy city street, and toward a more rarified and addictive stench compounded of chemicals that would one day be known to have contributed directly to society’s (and my own) madness and disease. It was necessary to obtain all available top light in the choked alleys, and Aanschultz had done everything he could in a city whose sky was blackly draped with burning sperm.

I came out into a dazzling light compounded of sunlight and acetylene, between walls yellowed by iodine vapor, covering my nose at the stench of mercury fumes, the reek of sulfur. My own fingertips were blackened from such stuff; and eczema procurata, symptomatic of a metol allergy, had sent a prurient rash all up the sensitive skin of my inner arms, which, though so bound in bandages that I could scarcely scratch them through my heavy woollen sleeves, were a constant seeping agony. At night I wore a woman’s long kid gloves coated with coal tar, and each morning dressed my wounds with an ointment of mercuric nitrate (60 g.), carbolic acid (10 ccs), zinc oxide (30 g) and lanoline (480 “), which I had learned to mix myself when the chemist professed a groundless horror of contagion. I had feared at first that the rash might spread over my body, down my flanks, invading the delicate skin of my thighs and those organs between them, softer by far. I dreaded walking like a crab, legs bowed far apart, experiencing excruciating pain at micturition and intercourse (at least syphilis is painless; even when it chews away one’s face, I am told, there is a pleasant numbness)–but so far this nightmare had not developed. Still, I held my tender arms slightly spread away from my sides, seeming always on the verge of drawing the twin Janssen photographic revolvers which I carried in holsters slung around my waist, popular hand-held versions of that amazing “gun” which first captured the transit of Venus across the face of our local star.

The laboratory, I say, was a fury of painfully brilliant light and sharp, membrane-searing smells. Despite my admiration for the Professor’s efficiency, I found it not well suited for artistic purposes, a side light being usually preferable instead of the glare of a thousand suns that came down through the cruelly contrived abat-jour. But Aanschultz, being of a scientific bent, saw in twilight landscapes only some great treasure to be prised forth with all necessary force. He would have disemboweled the earth itself if he thought an empirical secret were lodged just out of reach in its craw. I had suggested a more oblique light, but the Professor would not hear of it.

“That is for your prissy studios–for your fussy bourgeois sitters!” he would rage at my “aesthetic” suggestions. “I am a man of science. My subjects come not for flattering portraits, but for insight–I observe the whole man here.” To which I replied: “And yet you have not captured him. You have not impressed a single supposition on so much as one thin sheet of tin or silver or albumen glass. The fleeting things you see cannot be captured. Which is less than I can say of even the poorest photograph, however superficial.” And here he always scoffed at me and turned away, pacing, so that I knew my jibes had cut to the core of his own doubts, and that he was still, with relentless logic, stalking a way to fix the visions viewed so briefly (however engrossingly) in his praxiscope.

He needed lasting records of his studies–some substance the equivalent of photographic paper that might hold the scope’s pictures in place for all to see, for all time. It was this magical medium which he now sought. I thought it must be something of a “Deep” paper–a sheet of more than three dimensions, into which thoughts might be imprinted in all their complexity, a sort of mind-freezing mirror. When he shared his own ideas, I quickly became lost, and if I made any comment it soon led to vicious argument. I could not follow Aanschultz’s arguments on any subject; even our discussions of what or where to eat for lunch, what beer went best with bratwurst, could become incomprehensible. Only another genius could follow where Aanschultz went in his thoughts. With time I had even stopped looking in his eyes–with or without a psychopraxiscope.

“I am nearly there,” he told me today, as I reached the top of the stairs with a celebratory bottle in hand.

“You’ve found a way to fix the psychic images?”

“No–something new. My life’s work. This will live long after me.”

He said the same of every current preoccupation. His assistants were everywhere, adjusting the huge rack of movable mirrors that conducted light down from the rooftops, in from the street, over from the alleyway, wherever there happened to be a stray unreaped ray of it. Their calls rang out through the laboratory, echoing down through pipes like those in great ships, whereby the captain barks orders to the engine room. In the center of the chamber stood the solar navigator with his vast charts and compass and astrolabes scattered around him, constantly shouting into any one of the dozen pipes that coiled down from the ceiling like dangling vines, dispatching orders to those who stood in clearer sight of the sun but with a less complete foreknowledge of its motion; and as he shouted, the mirrors canted this way and that, and the huge collectors on the roof purred in their oiled bearings and the entire building creaked under the shifting weight and the laboratory burned like a furnace, although cleverly, without any heat. There was a watery luminescence in the air, a constant distorted rippling that sent wavelets lapping over the walls and tables and charts and retorts and tarnished boxes, turning the iodine stains a lurid green; this was the result of light pouring through racks of blue glass vials, old glass that had run and blistered with age, stoppered bottles full of copper sulphate which also swivelled and tilted according to the instructions of another assistant who stood very near the navigator. I had to raise my own bottle and drink very deeply before any of this made much sense to me, or until I could approach a state of focused distraction more like that of my friend and mentor, the great Professor Conreid Aanschultz, who now came at me and snatched the bottle from my hands and helped himself. He courteously polished every curve of the flask with a fresh chamois before handing it back, eradicating his last fingerprint as the bottle left his fingers, so that the now nearly empty vessel gleamed as brightly as those blue ones. I finished it off and dropped it in a half-assembled filter rack, where it would find a useful life even empty. The Professor made use of all Things.

“This way,” he said, leading me past a huge hissing copperclad acetylene generator of the dreadnought variety, attended by several anxious-looking children in the act of releasing quantities of gas through a purifier. The proximity of this somewhat dangerous operation to the racks of burning Bray 00000 lamps made me uncomfortable, and I was grateful to move over a light-baffling threshold into darkness. Here, a different sort of chaos reigned, but it was, if anything, even more intense and busy. I sensed, even before my eyes had adjusted to the weak and eerie working light, that these assistants were closer to Aanschultz’s actual current work, and that this work must be very near to completion, for they had that weary, pacified air of slaves who have been whipped to the very limits of human endurance and then suspended beyond that point for days on end. I doubted any had slept or rested for nearly as long as Aanschultz, who was possessed of superhuman reserves. I myself, of quite contrary disposition, had risen late that morning, feasted on a huge lunch (which even now was producing unexpected gases like my own internal rumbling dreadnought), and, feeling benevolent, had decided to answer my friend’s urgent message of the previous day, which had hinted that his fever pitch of work was about to bear fruit–a pronouncement he always made long in advance of the actual climax, thus giving me plenty of my own slow time to come around. For poor Aanschultz, time was compressed from line to point. His was a world of constant Discovery.

I bumped into nearly everything and everyone in the darkened chamber before my eyes adjusted, when finally I found myself bathed in a deep, rich violet light, decanted through yet another rack of bottles, although of a correspondingly darker hue. Blood or burgundy, they seemed at first; and reminded me of the liquid edge of clouds one sometimes sees at sunset, when all form seems to buzz and crackle as it melts into the coming night, and the eye tingles in anticipation of discovering unsuspected hues. My skin now hummed with this same subtle optical electricity. Things in the room seemed to glow with an inner light.

“Here we are,” he said. “This will make everything possible. This is my—


By this name Aanschultz referred to a bevelled opening he had cut into an odd corner of the room, a tight and complex angle formed between the floor and the brick abutment of a chimney shaft from the floors below. I could not see how he had managed to collect any light from this darkest of corners, but I quickly saw my error. For it was not light he bothered to collect in this way, but darkness.

Darkness was somehow channeled into the room and then filtered through those racks of purple bottles, in some of which I now thought to see floating specks and slowly tumbling shapes that might have been wine lees or bloodclots. I even speculated that I saw the fingers of a deformed, pickled foetus clutching at the rays that passed through its glass cell, playing inverse shadow-shapes on the walls of the dark room, casting its enlarged and gloomy spell over all us awed and frightened older children.

Unfiltered, the darkness was much harder to characterize; when I tried to peer into it, Aanschultz pulled me away, muttering, “Useless for our purposes.”

“Our?” I repeated, as if I had anything to do with this. For even then it seemed an evil power my friend had harnessed, something best left to its own devices–something which, in collaboration with human genius, could only lead to the worsening of an already precarious situation.

“This is my greatest work yet,” he confided, but I could see that his assistants thought otherwise. The shadows already darkening Europe seemed thickest in this corner of the room. I felt that the strangely beveled opening with its canted mirror inside a silvery-black throat, reflecting darkness from an impossible angle, was in fact the source of all unease to be found in the streets and in the marketplace. It was as if everyone had always known about this webby corner, and feared that it might eventually be prised open by the violent levering of a powerful mind.

I comforted myself with the notion that this was a discovery, not an invention, and therefore for all purposes inevitable. Given a mind as focused as Aanschultz’s, this corner was bound to be routed out and put to some use. However, I already suspected that the eventual use would not be that which Aanschultz expected.

I watched a thin girl with badly bruised arms weakly pulling a lever alongside the abat-nuit to admit more darkness through the purple bottles, and the deepening darkness seemed to penetrate her skin as well as the jars, pouring through the webs of her fingers, the meat of her arms, so that the shadows of bone and cartilege glowed within them, flesh flensed away in the revealing black radiance. It was little consolation to think that the discovery was implicit in the fact of this corner, this source of darkness built into the universe, embedded in creation like an aberration in a lens and therefore unavoidable. It had taken merely a mind possessed of an equal or complementary aberration to uncover it. I only hoped Aanschultz possessed the power to compensate for the darkness’s distortion, much as chromatic aberration may be compensated or avoided entirely by the use of an apochromatic lens. But I had little hope for this in my friend’s case. Have I mentioned it was his cruelty which chiefly attracted me?


Away from the axis. A term applied to the oblique or marginal rays passing through a lens. Thus the light of our story is inevitably deflected from its most straightforward path by the medium of the Encyclopaedia itself, and this entry in particular. Would that it were otherwise, and this a perfect world. Some go so far as to state that the entirety of Creation is itself an


A functional result of optical law. Yet I felt that this matter might be considered Aanschultz’s fault, despite my unwillingness to think any ill of my friend. In my professional capacity, I was surrounded constantly by the fat and the beautiful; the lazy, plump and pretty. They flocked to my studio in hordes, in droves, in carriages and cars, in swan-necked paddle boats; and their laughter flowed up and down the three flights of stairs to my studios and galleries, where my polite assistants bade them sit and wait until Monsieur Artiste might be available. Sometimes Monsieur failed to appear at all, and they were forced with much complaining to be photographed by a mere apprentice, at a reduced rate, although I always kept on hand plenty of pre-signed plates so that they might take away an original and be as impressive as their friends. I flirted with the ladies; was indulgent with the children; I spoke to the gentlemen as if I had always been one of them, concerned with the state of trade, rates of exchange, the crisis in labor, the inevitable collapse of economies. I was in short a chameleon, softer than any of them, lazier and more variable, yet prouder. They meant nothing to me; they were all so easy and pretty and (I thought then) expendable.

Yet there was only one Aanschultz. On the first and only day he came to sit for me (he had decided to require all his staff to wear tintype badges for security reasons and himself set the first example), I knew I had never met his like. He looked hopelessly out of place in my waiting chambers, awkward on the steep stairs, white and etiolated in the diffuse cuprous light of my abat-jour. Yet his eyes were livid; he had violet pupils, and I wished–not for the first time–that there were some way of capturing color with all my clever lenses and cameras. None of my staff colorists could hope to duplicate that hue. The fat pleasant women flocking the studios grew thin and uncomfortable at the sight of him, covering their mouths with handkerchiefs, exuding sharp perfumes of fear that neutralized their ambergris and artificial scents. He did not leer or bare his teeth or rub his hands and cackle; these obvious melodramatic motions would only have cheapened and blunted the sense one had of his refined cruelty.

Perhaps “cruel” is the wrong word. It was a severity in his nature–an unwillingness to tolerate any thought, sensation, or companion duller than a razor’s edge. I felt instantly stimulated by his presence, as if I had at last found someone against whom I could gauge myself, not as opponent or enemy, but as a student who forever tries and tests himself against the model of his mentor. In my youth I had known instinctively that it is always better to stay near those I considered my superiors; for then I could never let my own skills diminish, but must constantly be polishing and practicing them. With age and success, I had nearly forgotten that crucial lesson, having sheltered too long in the cozy nests and parlors of Society. Aanschultz’s laboratory proved to be their perfect antidote.

We two could not have been less alike. As I have said, I had no clear understanding of, and only slightly more interest in, the natural sciences. Art was All, to me. It had been my passion and my livelihood for so long now that I had nearly forgotten there was any other way of life. Aanschultz reintroduced me to the concepts of hard speculation and experimentation, a lively curriculum which soon showed welcome results in my own artistic practices. For in the city, certain competitors had mastered my methods and now offered similar services at lower prices, lacking only the fame of my name to beat me out of business. In the coltish marketplace, where economies trembled beneath the rasping tongue of forces so bleak they seemed the product of one’s own fears, with no objective source in the universe, it began to seem less than essential to possess an extraordinary signature on an otherwise ordinary photograph; why spend all that money for a Name when just down the street, for two-thirds the price, one could have a photograph of equivalent quality, lacking only my florid famous autograph (of which, after all, there was already a glut)? So you see, I was in danger already when I met Aanschultz, without yet suspecting its encroachment. With his aid I was soon able to improve the quality of my product far beyond the reach of my competitors. Once more my name reclaimed its rightful magic potency, not for empty reasons, not through mere force of advertising, but because I was indeed superior.

To all of Paris I might have been a great man, an artistic genius, but in Aanschultz’s presence I felt like a young and stupid child. The scraps I scavenged from his workshop floors were not even the shavings of his important work. He hardly knew the good he did me, for although an immediate bond developed between us, at times he hardly seemed aware of my presence. I would begin to think that he had forgotten me completely; weeks might pass when I heard not a word from him; and then, suddenly, my faith in our friendship would be reaffirmed, for out of all the people he might have told–his scientific peers, politicians, the wealthy–he would come to me first with news of his latest breakthrough, as if my opinion were of greatest importance to him. I fancied that he looked to me for artistic inspiration (no matter how much he might belittle the impulse) just as I came to him for his scientific rigor.

It was this rigor which at times bordered on cruelty–though only when emotion was somehow caught in the slow, ineluctably turning gears of his logic. He would not scruple to destroy a scrap of human fancy with diamond drills and acid blasts in order to discover some irreducible atom of hard fact (+10 on the Mohs’ scale) at its core. This meant, unfortunately, that each of his advances had left a trail of crushed “victims,” not all of whom had thrown themselves willingly before the juggernaut. I sensed that this poor girl would soon be one of them.


of a curious sort covered her arms, something like a cross between bruises, burns and blistering. Due to my own eczema, I felt a sympathic pang as she backed away from the levers of the abat-nuit, Aanschultz brushing her off angrily to make the final adjustments himself. She looked very young to be working such long hours in the darkness, so near the source of those strange black rays, but when I mentioned this to my friend he merely swept a hand in the direction of another part of the room, where a thin woman lay stretched out on a stained pallet, her arm thrown over her eyes, head back, mouth gaping; at first she appeared as dead as the drowned poseur Hippolyte Bayard, but I saw her breast rising and falling raggedly. The girl at the lever moved slowly, painfully, over to this woman and knelt down beside her, then very tenderly laid her head on the barely moving breast, so that I knew they were mother and child. Leaving Aanschultz for the moment, I sank down beside them, stroking the girl’s frayed black hair gently as I asked if there were anything I could do for them.

“Who’s there?” the woman said hoarsely.

I gave my name, but she appeared not to recognize it. She didn’t need illustrious visitors now, I knew.

“He’s with the Professor,” the child said, scratching vigorously at her arms though it obviously worsened them. I could see red, oozing meat through the scratches her fingernails left.

“You should bandage those arms,” I said. “I have sterile cloth and ointment in my carriage if you’d like me to do it.”

“Bandages and ointment, he says,” said the woman. “As if there’s any healing it. Leave her alone now–she’s done what she could where I had to leave off. You’ll just get the doctor mad at both of us.”

“I’m sure he’d understand if I—”

“Leave us be!” the woman howled, sitting up now, propped on both hands so that her eyes came uncovered, to my horror; for across her cheeks, forehead and nose was an advanced variety of the same damage her daughter suffered; her eyesockets held little heaps of charred ash that, as she thrust her face forward in anger, poured like black salt from between her withered lids and sifted softly onto the floor, reminding me unavoidably of that other and most excellent abrading powder which may be rubbed on dried negatives to provide a “tooth” for the penciller’s art, consisting of one part powdered resin and two parts cuttle-fish bone, the whole being sifted through silk. I suspected this powder would do just as well, were I crass enough to gather it in my kerchief. She fell back choking and coughing on the black dust, beating at the air, while her daughter moved away from me in tears, and jumped when she heard Aanschultz’s sharp command.

I turned to see my friend beckoning with one crooked finger for the girl to come and hold the levers just so while he screwed down a clamp.

“My God, Aanschultz,” I said, without much hope of a satisfactory answer. “Don’t you see what your darkness has done to these wretches?”

He muttered from the side of his mouth: “It’s not a problem any longer. A short soak in a bath of potassium iodide and iodine will protect the surface from abrasion.”

“A print surface, perhaps, but these are people!”

“It works on me,” he said, thrusting at me a bare arm that showed scarcely any scarring. “Now either let the girl do her work, or do it for her.”

I backed away quickly, wishing things were otherwise; but in those days Aanschultz and his peers needed fear no distracting investigations from the occupational safety officials.  He could with impunity remain oblivious to everything but the work that absorbed him.


This term is used in a chemical, an optical, and an esoteric sense. In the first case designates the taking up of one substance by another, just as a sponge absorbs or sucks up water, with hardly any chemical but merely a physical change involved; this is by far the least esoteric meaning, roughly akin to those surface phenomena which Aanschultz hoped to strip aside. Optically, absorption is applied to the suppression of light, and to it are due all color effects, including the dense dark stippling of the pores of Aanschultz’s face, ravaged by the pox in early years, and the weird violet aura–the same color as his eyes, as if it had bled out of them–that limned his profile as he bent closer to that weirdly angled aperture into artificial darkness.

My friend, with unexpected consideration for my lack of expertise, now said: “According to Draper’s law, only those rays which are absorbed by a substance act chemically on it; when not absorbed, light is converted into some other form of energy. This dark beam converts matter in ways heretofore unsuspected, and is itself transformed into a new substance. Give me my phantospectroscope.”

This last command was meant for the girl, who hurriedly retrieved a well-worn astrolabe-like device from a concealed cabinet and pressed it into her master’s hands.

“The spectrum is like nothing ever seen on this earth,” he said, pulling aside the rack of filter bottles and bending toward his abat-nuit with the phantospectroscope at his eye, like a sorcerer stooping to divine the future in the embers of a hearth where some sacrifice has just done charring. I could not bear the cold heat of that unshielded black fire. I took several quick steps back.

“I would show you,” he went on, “but it would mean nothing to you. This is my real triumph, this phantospectroscope; it will be the foundation of a new science. Until now, visual methods of spectral inspection have been confined to the visible portion of the spectrum; the ultraviolet and infrared regions gave way before slow photographic methods; and there we came to a halt. But I have gone beyond that now. Ha! Yes!”

He thrust the phantospectroscope back into the burned hands of his assistant and made a final adjustment to the levers that controlled the angle and intensity of rays conducted through the abat-nuit. As the darkness deepened in that clinical space, it dawned on me that the third and deepest meaning of absorption was something like worship, and not completely dissimilar to terror.


my friend shouted, and I sensed rather than saw the girl moving toward him, but too slowly. Common accelerators are sodium carbonate, washing soda, ammonia, potassium carbonate, sodium hydrate (caustic soda), and potassium hydrate (caustic potash), none of which suited Aanschultz. He screamed again, and now there was a rush of bodies, a crush of them in the small corner of the room. An accelerator shortens the duration of development and brings out an image more quickly, but the images he sought to capture required special attention. As is written in the Encylopaedia of Photography (1911, exoteric edition), “Accelerators cannot be used as fancy dictates.” I threw myself back, fearful that otherwise I would be shoved through the gaping abat-nuit and myself dissolve into that negative essence. I heard the girl mewing at my feet, trod on by her fellows, and I leaned to help her up. But at that moment there was a quickening in the evil corner, and I put my hands to a more instinctive use.


The darkness cupped inside my palms seemed welcoming by comparison to the anti-light that had emptied the room of all meaning. With both eyes covered, I felt I was beyond harm. I could not immediately understand the source of the noises and commotion I heard around me, nor did I wish to. (See also, “Axial Accommodation.”)


Apparently (and this I worked out afterward in hospital beside Aanschultz) the room had absorbed its fill of the neutralizing light. All things threatened to split at their seams. Matter itself, the atmosphere, Aanschultz’s assistants, bare thought, creaking metaphor–these things and others were stuffed to the bursting point. My own mind was a peaking crest of images and insights, a wave about to break. Aanschultz screamed incomprehensible commands as he realized the sudden danger; but there must have been no one who still retained the necessary self-control to obey him. My friend himself leapt to reverse the charge, to shut down the opening, sliding the rack of filtering jars back in place–but even he was too late to prevent one small, significant rupture.

I heard the inexplicable popping of corks, accompanied by a simultaneous metallic grating, followed by the shattering of glass. Aanschultz later whispered of what he had glimpsed out of the edges of his eyes, and by no means can I–nor would I–discredit him.

It was the bottles and jars in the filter rack that burst. Or rather, some burst, curved glass shards and gelatinous contents flying, spewing, dripping, clotting the floor and ceiling, spitting backward into the bolt-hole of night. Other receptacles opened with more deliberation. Aanschultz later blushed when he described, with perfect objectivity, the sight of certain jar lids unscrewing themselves from within. The dripping and splashes and soft wet steps I heard, he said, bore an actual correspondence in physical reality, but he refused ever to go into further detail on exactly what manner of things, curdled there and quickened in those jars by the action of that deep black light, leapt forth to scatter through the laboratory, slipping between the feet of his assistants, scurrying for the shadows, bleeding away between the planks of the floor and the cracks of our minds, seeping out into the world. My own memory is somewhat more distorted by emotion, for I felt the girl clutching at my ankles and heard her terrible cries. I forced myself to tear my hands away from my face–while still keeping my eyes pressed tight shut–and leaned down to offer help. No sooner had I taken hold of her fingers than she began to scream more desperately. Fearing that I was aggravating her wounds, I relaxed my hands to ease her pain; but she clung even more tightly to my hands and her screams intensified. It was as if something were pulling her away from me, as if I were her final anchor. As soon as I realized this, as soon as I tried to get a better hold on her, she slipped away. I heard her mother calling. The girl’s cries were smothered. Across the floor rushed a liquid seething, as of a sudden flood draining from the room and down the abat-nuit and out of the laboratory entirely.

My first impulse was to follow, but I could no longer see a thing, even with my eyes wide open.

“A light!” I shouted, and Aanschultz overlapped my own words with his own: “No!”

But too late. The need for fire was instinctive, beyond Aanschultz’s ability to quell by force or reason. A match was struck, a lantern lit and instantly in panic dropped; and as we fled onrushing flames, in that instant of total exposure, Aanschultz’s most ambitious and momentous experiment reached its climax…although the denouement for the rest of Europe and the world would be a painful and protracted one.


(See “Aldehyde.”)


The oldest of acids, with many uses in photography, in early days as a constituent of the developer for wet plates, later for clearing iron from bromide prints, to assist in uranium toning, and as a restrainer. It is extremely volatile and should be kept in a glass-stoppered bottle and in a cool place.


Synonym, ethyl acetate. A light, volatile, colorless liquid with pleasant acetous smell, sometimes used in making collodion. It should be kept in well-stoppered bottles away from fire, as the vapor is very inflammable.


A colorless volatile liquid of peculiar and characteristic odor, with two separate and distinct uses in photography, as an addition to developers and in varnish making. As the vapor is highly inflammable, the liquid should be kept in a bottle with a close-fitting cork or glass stopper.


The old, and now obsolete, name for acetic acid (which see). Highly inflammable.


A hydrocarbon gas having, when pure, a sweet odor, the well known unpleasant smell associated with this gas being due to the presence of impurities. It is formed by the action of water upon calcium carbide, 1 lb. of which will yield about 5 ft. of gas. It burns in air with a very bright flame, and is largely used by photographers for studio lighting, copying, etc., and as an illuminant in enlarging and projection lanterns. Acetylene forms, like other combustible gases, an explosive mixture with ordinary air, the presence of as little as 4 per cent. of the gas being sufficient to constitute a dangerous combination.


An apparatus for generating acetylene by the action of water on calcium carbide. Copper should not be employed in acetylene generators, as under certain conditions a detonating explosive compound is formed.


Wratten and Mees prepared a silver acetylide emulsion by passing acetylene into an ammoniacal solution of silver nitrate and emulsifying in gelatin the precipitate, which is highly explosive. While this substance blackens in daylight about ten times faster than silver chloride paper, for years observers failed to detect any evidence of latent image formation and concluded that insights gained in Professor Conreid Aanschultz’s laboratory were of no lasting significance. This misunderstanding is attributed to the fact that, despite the intensity of exposure, it has taken more than a century for certain crucial images to emerge, even with the application of strong developers. We are only now beginning to see what Aanschultz glimpsed in an instant.

“What man may hereafter do, now that Dame Nature has become his drawing mistress, is impossible to predict.”

— Michael Faraday

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“Great Breakthroughs in Darkness” copyright 1992 by Marc Laidlaw. First appeared in New Worlds #2 (1992), edited by David Garnett.