The chemical gardens by Groupe Traces

Since the dawn of time, explaining the origin of life from nothingness has generated much passion and polemic. Over a century ago, Stéphane Leduc, a French professor of medicine, attempted to duplicate this phenomenon. His work led to the invention of synthetic biology which created a great stir among the scientific community at the time. However, was he really misguided? What can be said is that the work carried out by this ingenious experimenter opened the way for as much scholarly research as violent debate. At the outer edges of science, on the borders of metaphysics, two chemists and a photographer have copied this scientist's work. They have reinterpreted the illegible scribbles of the mad scholar in the light of the fabulous phenomenon of osmosis. An insight into their secret laboratory over a three-day period.

The chemical gardens. Photos ©Stephane Querbes Text ®Etienne Colomb/K-Minos Original idea ©R.E Eastes -C. Darrigan Contact - Thierry Tinacci Lightmediation Photo Agency +33 (0)6 61 80 57 21 thierry@lightmediation.com

1278-05: StĂŠphane Leduc's initial work focused on the reproduction of biological cells. This osmotic cell has developed around a fragment of melted calcium chloride introduced into a highly diluted solution of sodium silicate. In these preliminary experiments, mineral matter already resembles living matter to such an extent that it would be easy to be misled.

1278-02: Detail from an experiment conducted using ferric chloride crystals. What could be more disturbing than the sight of this aquatic snail, the origin of which is purely mineral, moving gracefully

1278-03: Synthesised under the same conditions, this expanding sea anemone looks just as full of life. It is undoubtedly the combination of beauty and physicochemical principles which make these experiments

1278-04: The combination of the same ingredients (ferric chloride and sodium silicate) leads to an infinite variety of osmotic growths which may be downwards, taking the form of folds, or upwards, in bunches and

1278-06: Osmotic growths develop at different paces, alternating between a phase of apparent tranquillity and sudden accelerations. In this picture, the movement of the manganese sulphate has been captured

1278-08: Despite the quality of Leduc's experimental results, and even though they contributed to clarifying the debate on spontaneous generation, the scientific community never allowed itself to be

1278-09: Introduced into a Plexiglas aquarium at intervals from each other, the different types of crystal flourish according to their own methods of growth and at different speeds.

1278-10: After about ten minutes, the growth of the branches stops and the filaments spread across the surface taking the form of partially submerged layers.

1278-12: Metallic salt crystals must be introduced delicately in order to limit turbulence which is generated when they are placed in the solution.

1278-30: typical template from the French and English versions of StĂŠphane Leduc's books.

1278-31: typical template from the French and English versions of StĂŠphane Leduc's books.

1278-13: Each metallic salt has its own type of growth: nickel salts cover the bottom of the aquarium in the same way as a fine lawn on which flourishes the cobalt chloride, the calcium chloride and the ferric

1278-14: After 45 minutes of growth, the chemical garden is finished. If protected from vibrations, it may last for several days before collapsing into tiny fragments.

1278-15: When they reach the sides of the aquarium, the osmotic growths attach themselves to it and develop, offering an insight into the intimacy of their interior space.

1278-16: Start of the growth of cobalt chloride. The hatching of the bubble, formed by the air initially imprisoned in the aggregate, appears to play a decisive role in the rest of the process.

1278-01: When introduced into liquid known as "water-glass" (in reality a concentrated sodium silicate solution in a Plexiglas aquarium), after a few minutes copper sulphate crystals generate magnificent ephemeral and mineral landscapes. Behind, these tubular or filiform growths, the chemists identified several phenomena such as osmosis, variations in the density of the liquid and the formation of air bubbles within it.

1278-17: Unfortunately, the bubble is too large and quickly detaches itself, thus interrupting the growth of a large tube.

1278-18: This is quickly replaced by filaments, the much faster growth of which is also more dispersed and less predictable.

1278-20: T = 0. When different metallic salts are mixed before being introduced into the sodium silicate solution, instead of being easy to distinguish, anything is possible?

1278-21: T = 3 minutes.

1278-22: T = 10 minutes.

1278-23: T = 30 minutes.

1278-24: Nickel nitrate crystals.

1278-33: Tubular and filiform growths of copper sulphate (close-up). The influence of air bubbles produced by the degassing of the solution is particularly visible.

1278-25: Potassium hexacyanoferrate crystals.

1278-26: Manganese sulphate crystals.

1278-27: Calcium chloride crystals.

1278-20: T = 0. When different metallic salts are mixed before being introduced into the sodium silicate solution, instead of being easy to distinguish, anything is possible?

1278-29: Observation: one of the keys to the scientific approach. This is the moment when the researcher's reasoning and creativity intervenes.

1278-30: typical template from the French and English versions of Stéphane Leduc's books.

1278-31: typical template from the French and English versions of Stéphane Leduc's books.

1278-32: Osmotic productions of all sorts (mushrooms, madreporaria, efflorescence, annelida, etc.) obtained by Stéphane Leduc and reproduced in the English version of his book.

1278-42: Hollow tube of fulgurite produced by lightning striking the sand.

1278-34: The exuberant growth of iron chloride (III) gives rise to some of the most evocative forms.

1278-35: The exuberant growth of iron chloride (III) gives rise to some of the most evocative forms.

1278-36: Microscopic crystallisations of calcium chloride, invisible to the naked eye, form the wall of the osmotic cell which has grown around the original fragment.

1278-14: After 45 minutes of growth, the chemical garden is finished. If protected from vibrations, it may last for several days before collapsing into tiny fragments.

1278-41: Osmotic productions by Stéphane Leduc.

1278-38: Cobalt chloride crystals.

1278-39: Nickel sulphate crystals.

1278-40: Osmotic productions by Stéphane Leduc.

Osmotic effects. Since the dawn of time, explaining the origin of life from nothingness has generated much passion and polemic. Over a century ago, Stéphane Leduc, a French professor of medicine, attempted to duplicate this phenomenon. His work led to the invention of synthetic biology which created a great stir among the scientific community at the time. However, was he really misguided? What can be said is that the work carried out by this ingenious experimenter opened the way for as much scholarly research as violent debate. At the outer edges of science, on the borders of metaphysics, two chemists and a photographer have copied this scientist's work. They have reinterpreted the illegible scribbles of the mad scholar in the light of the fabulous phenomenon of osmosis. An insight into their secret laboratory over a three-day period. Investigation and report.

RECREATING LIFE: THE POWER OF OSMOSIS "For physicians, chemists and biologists explaining the universe, matter and life means, above all, trying to understand them in order to then be able to use them, control them, copy them and even recreate them" explain the two chemists, Richard-Emmanuel Eastes and Clovis Darrigan, "Agrégé" Professor at the Ecole Normale Supérieure de Paris and Associate Professor at the University of Pau respectively. In order to move from theory to practice, it was through the discovery of work dating from almost one

century ago that the two researchers decided to set off in the footsteps of a French scientist by the name of Leduc, in order to repeat his experiments designed to recreate life from mineral substances and, thus, demonstrate that no "vital principle" is necessary for its origin. These experiments created a great stir among the scholarly community at the start of the last century: in effect Louis Pasteur, the inventor of vaccines, a sworn enemy of spontaneous generation, put an end to the debate which still led people to believe that life could appear spontaneously, without any pre-defined programme, as a result of random molecular encounters. Nevertheless, Stéphane Leduc's hypotheses were simple: if he succeeded in recreating forms similar to those which produced life and then in understanding the mechanisms of their formation, perhaps he would be able to understand life itself! Developed in a successful book published in 1910, the results of his research conducted in this field made some headway, especially in the English-speaking world, before finally being refuted. However, in France, they very quickly led to his exclusion from the scientific community, probably as a result of the growing influence of Pasteur. And yet, for these two chemists, things are far from being quite as simple and this work, cast aside too quickly without due consideration, should be looked at more closely in the light of present-day knowledge because, on the one hand, at the dawn of the 21st century, the mystery of the origins of life has still not been solved, and, on the other hand, because, as they explain, "if man was mistaken, this work, noted down in carefully written manuscripts, offers a path to understanding physicochemical

phenomena of major importance". In effect, it is the incredible phenomenon of osmosis, omnipresent in all his experiments, which is the cornerstone of Leduc's thinking: "Of all the ordinary physical forces, osmotic pressure and osmosis alone appear to possess this remarkable power of organisation and morphogenesis". Osmosis, the phenomenon which allows water to pass through biological membranes, as a result, finds itself a part of almost all types of mechanisms which are indispensable to life? IN THE FOOTSTEPS OF LEDUC: INITIAL EFFLORESCENCES "The historical experiments of Stéphane Leduc which we are about to rediscover are not very well known. Nevertheless, they are relatively easy to carry out, at least in their most elementary form" explain the two scientists. Starting at dawn, in the silence of an abandoned laboratory at the University of Pau, accompanied by the specialist macrophotographer, Stéphane Querbes, they are going to attempt to capture images of these astonishing, ephemeral osmotic growths, wonderful simulations of life. They gather their equipment together, check the cleanliness of their beakers, Erlenmeyer flasks and other volumetric containers, and neatly lay out the small bottles which, later, will produce the metal salts they have carefully selected. The photographer studies the layout of the room and the light sources and sets up his spotlights, screens and other state-of-the-art equipment. Above all, they explain, "we are preparing the essential component of all our experiments, the "vital liquid" for osmotic growths: the concentrated sodium silicate solution or "water-glass", which will serve as the "stock solution".

The writings from which they have drawn their inspiration are entitled "Théorie physico-chimique de la vie et générations spontanées". Although they are old and require interpretation, the experiments have been outlined with great precision. "Leduc uses "melted" calcium chloride which we obtain by heating the naturally hydrated product" explains Clovis Darrigan. Richard-Emmanuel Eastes continues: "We observe an initial ebullition which corresponds to the evaporation of crystallisation water followed by actual fusion at a temperature of about 770°C. The calcium chloride takes on a paste-like texture and we use a spatula to remove it from the crucible in order to create amorphous fragments. This fusion recommended by Leduc permits the elimination of trapped gas bubbles which hinder growth".

With great care, Clovis Darrigan introduces a fragment of calcium chloride into the sodium silicate solution. The latter fixes itself to the surface of the liquid, hesitates for a second and, then, suddenly dives down before gently settling at the bottom of the recipient. This is the point at which the first osmotic cell starts to grow around the initial fragment in the same way as those in our body. There is an atmosphere of great excitement! For the explorers of matter, which we are, the success of this first attempt at morphogenesis, worthy of real-life larval or plant growths, is a wonderful gift. "But, the comparisons do not end there!" observe the scientists who, once they have come back down to earth, are very careful about comparing their first experience of synthesis to any sign of life. They continue by explaining that "after several years of glory, Leduc's ideas were

very quickly swept aside by the convergence of new knowledge emerging in the fields of chemistry, astronomy and, of course, genetics; that is why the writings of philosophers and science historians tend to do greater justice to these hypotheses, which, today, appear to us to be wild theories". A TRAGIC STORY It was after 1907 that StĂŠphane Leduc encountered the most severe opposition, except in England and the United States where recent research on the question by Louis Pasteur had not yet achieved enough importance in public opinion to be an obstacle to Leduc's hypotheses. Later, when the biologist Alexandre Oparine referred to him in his book Origins of life in 1936, it was only in order to point out that the similarity between his productions and biological cells was "no greater than a superficial resemblance between a living person and a marble statue". "Yet, in science, errors can sometimes open new lines of thought" emphasises Richard-Emmanuel Eastes. He has a critical and compassionate opinion of the tragic story of this idealist, scorned by his peers for having forgotten the duty of non-disclosure which is imposed by science: that of not giving in to the enthusiasm inspired by the beauty of natural phenomena, that of allowing oneself all possible means to check that one's hypotheses are irrefutable before declaring them a miracle. Nevertheless, in defence of Leduc, and on the basis of the images which we can still discover today, it has to be said that it must have been difficult not to have believed... He continues by saying: "Although his

results were far from miraculous and his assertions were often unfounded, they were not without interest. By filling the theoretical void which, until then, separated the living from the non-living, by offering a new version of the "missing link" between inorganic and organic, his experiences started by casting a decisive light on the nature and origin of life". In effect, as Evelyn Fox Keller, the famous biology historian explains: "Leduc's models responded to a much felt need at the time, although it is not the case nowadays: they demonstrated that complex forms (similar in complexity to those to be found in the living world) could be engendered by properly identified physical and chemical processes". THREE DAYS TO UNDERSTAND This was the challenge which the two chemists and the photographer set for themselves. After the first day of experimental exploration, they decided to be more systematic and test all the possible combinations by introducing the different metal salts which they had at their disposal into stock solutions of varying concentrations. They obtained a wide range of results, from the most promising to the most disappointing. They also noticed that, out of all the preparations, it was the simplest one which gave the best results and that all the others - mixtures of different solutions of varying concentrations - were probably only devised by Leduc within very specific frameworks designed to give strength to his theory: the intentional creation of the largest number of forms possible resembling living beings such as mushrooms, shells, leaves, madreporaria and other annelida. THE ROLE OF GAS BUBBLES... Sometimes, the two chemists'

observations were more critical: "Each of the experiments we conducted was an opportunity to make new observations which we listed meticulously in our laboratory notebook. One of them was going to allow us to refute definitively one of Leduc's arguments concerning the mechanism which we explored the most: that of vermiform and filiform growth". For Leduc, who was ready to do anything to defend the unique influence of osmosis on these phenomena, "the slightest consideration will show the inadequacy of the usual explanation that the growth is due to mere differences of density, or to amorphous precipitation around bubbles of gas. These may indeed affect the phenomenon, but can in no way be regarded as its cause". However, on the contrary, a century later, with the help of the modern techniques of macrophotography, the observations have permitted the two researchers to highlight the fundamental influence of gas bubbles, the production of which is stimulated by the degassing of the stock solution under the influence of the heat from the floodlights. In effect, whenever they accompany the birth of arborescent stems, these bubbles hugely accelerate their growth before separating from them, thus interrupting the process abruptly. Nevertheless, throughout their explorations the two chemists do not allow themselves to be distracted by their own observations, never lose sight of their initial objectives and try to understand why Leduc was wrong, despite the firm beliefs which he had acquired through his experimentations. As he had, they asked themselves: "Is it possible to doubt that the simple conditions which produce an osmotic growth have frequently been realised during the past ages of the earth?" StĂŠphane Leduc is certain:

"Millions of ephemeral forms must have succeeded one another in the natural evolution of that age, when the living world was represented by matter thus organised by osmosis". The two researchers deduce that "it renews, the almost metaphysical dimension which, in 1827, was attributed already to the phenomenon of osmosis after its discovery by Abbot Nollet: "osmosis is the point at which the physics of living bodies and the physics of inorganic bodies merge". A SLOW PROCESS OF REHABILITATION It is the third and last day of work in the laboratory before moving on to a more detailed analysis of the images. The trio note that "the main work has been done but there are still many variants to be tested". The photographer, StĂŠphane Querbes, sighs: "The thousands of photographs we have taken are not enough to duplicate the infinite diversity of shapes and colours which Leduc's original work is likely to offer us". But, the team's smiles suggest that this minor frustration has now been largely compensated for by their belief that they now possess a small piece of his know-how and experimental intuition. In view of the variety of shapes and expressions produced by the inert matter, we can feel the difficulty of resisting the temptation to see life where no life is to be found. Nevertheless, recently, this is precisely the objective which Leduc's work has served, in complete contradiction to its original purpose: in effect, researchers have been able to demonstrate that certain concrescences, such as fulgurite, which, to date, palaeontologists had considered to be fossils, were probably nothing more than the remains of mineral formations, therefore, originally, completely... inert.

"So, what remains of Stéphane Leduc's work from the point of view of contemporary research?" we ask our two chemists. They philosophise that "this is often the case when "real" science considers questions which have been relegated to fields qualified as "parascientific", thus wiping the slate clean of all existing interpretations evoked over the centuries. Today, research conducted in this field almost never refers to the pioneering work of Stéphane Leduc. Given this, our work to rehabilitate his name is slowly making progress; as a result of it, it is now possible to find his name in the transcription of a lesson given at the Collège de France at the end of 2006 on the subject of chemical morphogenesis". However, apart from this historic rehabilitation, now that the subject has been placed, once again, in the spotlight and analysed in the light of modern-day knowledge and better understood as a result of the techniques of macrophotography, Leduc's work is now likely to open new research paths. It is in these terms that Richard-Emmanuel Eastes explains to us that, on the basis of the experiments described here, he has just initiated "an interdisciplinary research project designed to understand the way in which the lungs of embryos are formed". THE ENIGMA OF LIFE: AN UNSOLVED MYSTERY Although this new research continues to explore the boundaries between the inert and the living, some mysteries still remain unsolved. It is true that the mechanisms of life are physicochemical and Leduc's contribution to establishing this certainty is

considerable. Furthermore, ever since Pasteur's time, we are almost certain that living things are not born spontaneously from matter. But the question which neither Leduc nor Pasteur were able to answer is perhaps the most important one of all: "Where does life come from?" At the dawn of the third millennium, the answer to this question is still not known. "Inanimate objects do you have a soul?" wrote Lamartine, the Romantic poet. It was a remarkable piece of intuition. For further information contact richard-emmanuel.eastes@ens.fr and/or consult: S. Leduc, Les bases physiques de la vie et la biogenèse (The Mechanism of Life), Masson, Paris, 1906 and S. Leduc, La biologie synthétique, étude de biophysique, A. Poinat, Paris, 1912. The second work is available online at www.peiresc.org/bstitre.htm E. Fox Keller, Making Sense of Life: Explaining Biological Development with Models, Metaphors and Machines, Harvard University Press, 2002. The slides from Professor J. Livage's lecture at the Collège de France and R.-E. Eastes' seminar are available at the page www.labos.upmc.fr/lcmcp/livage/cours_col lege.html

APPENDIX To make beautiful chemical gardens... Obtain a shop-bought solution of sodium silicate and dilute it twice with distilled and, preferably, degassed water1. Use it within the next few hours. Pour it into a Plexiglas2 recipient measuring 10 to 15 centimetres in height. Leave it to rest a few minutes. Add some small well chosen crystals of metal salts: CuSO4, Ni(NO3)2, FeCl3,

CoCl2, MnSO4... Those for "chemical garden" kits sold by chemical product suppliers are perfectly suitable. Avoid piling up the crystals and laying them out too close to one another and, above all, avoid shaking the recipient. Observe3. Mechanism of osmotic growth Once introduced into the stock solution, the metal salts (calcium chloride, iron, nickel, copper, manganese, cobalt salts, etc.) dissolve. When they come into contact with the silicate ions, the freed metal ions immediately form a solid membrane around the initial crystal. The "cell" is born. "This membrane is "semi-permeable": it allows water to pass through, but no other substance. After this, it delimits two areas: an internal solution containing only the dissolved metallic salt and an external solution containing only the sodium silicate (also dissolved). For reasons which only chemical thermodynamism is able to explain, this difference in composition results in an inflow of water through the membrane, from the exterior to the interior. This phenomenon is called "osmosis", and led Leduc to give the cell its "osmotic" quality. The growth of the cell still remains to be understood: this inflow of water leads to an increase in the internal pressure, and then the rupture of the membrane which is reformed immediately... but, slightly further away. The phenomenon is repeated continually over its entire circumference and the cell grows. However, in most cases, the density of the interior solution is lower that that of the external environment: therefore, the rupture tends to be upwards. This means that growth is ascendant, filamentary and arborescent.

Quotes "I commandeered the kitchen table to make a 'chemical garden', sowing a syrupy solution of sodium silicate, or water-glass, with differently coloured salts of iron and copper and chromium and manganese. This produced not crystals but twisted, plantlike growths in the water-glass, distending, budding, bursting, continually reshaping themselves before my eyes". Chemical recreations in Uncle Tungsten, Oliver Sacks4 "[...] Leverkuhn's father asked us what we thought about it, we replied shyly that they could not be plants, to which he declared: "It is true, they are nothing of the sort, they are pretending; but, this does not diminish their merit. It is precisely the fact that they simulate and try their hardest which is worthy of our respect." Doctor Faustus, Thomas Mann5 1 It is possible to degas water by simply boiling it. 2 The hyperbasic solution attacks glass and the osmotic growths adhere to it with great force. 3 If the recipient is covered and protected from vibrations, the arborescences may be kept for several weeks. 4 Sacks, O. Uncle Tungsten, Alfred A. Knopf, 2001. 5 Mann, T. Doctor Faustus, Alfred A. Knopf, 1948.

Captions. 1278-01: When introduced into liquid known as "water-glass" (in reality a concentrated sodium silicate solution in a Plexiglas aquarium), after a few minutes copper sulphate crystals generate magnificent ephemeral and mineral landscapes. Behind, these tubular or filiform growths, the chemists identified several phenomena such as osmosis, variations in the density of the liquid and the formation of air bubbles within it. 1278-02:Detail from an experiment conducted using ferric chloride crystals. What could be more disturbing than the sight of this aquatic snail, the origin of which is purely mineral, moving gracefully across the bottom of the aquarium? 1278-03: Synthesised under the same conditions, this expanding sea anemone looks just as full of life. It is undoubtedly the combination of beauty and physicochemical principles which make these experiments so fascinating. 1278-04: The combination of the same ingredients (ferric chloride and sodium silicate) leads to an infinite variety of osmotic growths which may be downwards, taking the form of folds, or upwards, in bunches and filaments. Everything happens within the space of just a few minutes! 1278-05: StĂŠphane Leduc's initial work focused on the reproduction of biological cells. This osmotic cell has developed around a fragment of melted calcium chloride introduced into a highly diluted solution of sodium silicate. In these preliminary experiments, mineral matter

already resembles living matter to such an extent that it would be easy to be misled. 1278-06: Osmotic growths develop at different paces, alternating between a phase of apparent tranquillity and sudden accelerations. In this picture, the movement of the manganese sulphate has been captured miraculously by the photographic equipment. It is not surprising that Leduc saw these phenomena as a sign of a form of primitive life!

1278-11: The interface between two solutions of different concentrations and, therefore, of different densities, at a third of its height results in a change in the behaviour of growing cobalt chloride. This was one of the many variants devised by Leduc to recreate forms similar to those in life. 1278-12: Metallic salt crystals must be introduced delicately in order to limit turbulence which is generated when they are placed in the solution.

1278-19: Suddenly a second filament appears from nowhere, joins the first and follows a looping path similar to the first. It is such unlikely behaviour that the researchers are unable to understand it? 1278-20: T = 0. When different metallic salts are mixed before being introduced into the sodium silicate solution, instead of being easy to distinguish, anything is possible? 1278-21: T = 3 minutes.

1278-07: An extraordinary diversity of colours and forms may be obtained with cobalt chloride depending on local variations in its level of hydration or its degree of oxidation. The presence of air bubbles may also intervene in the development process. 1278-08:Despite the quality of Leduc's experimental results, and even though they contributed to clarifying the debate on spontaneous generation, the scientific community never allowed itself to be convinced of the link between osmotic growths and signs of life: this association of various crystals of different sorts certainly resembles a coral reef; nevertheless, no living being has contributed to it or has spent any time in it. It is the work of mineral forces alone. 1278-09:Introduced into a Plexiglas aquarium at intervals from each other, the different types of crystal flourish according to their own methods of growth and at different speeds. 1278-10: After about ten minutes, the growth of the branches stops and the filaments spread across the surface taking the form of partially submerged layers.

1278-22: T = 10 minutes. 1278-23: T = 30 minutes. 1278-24: Nickel nitrate crystals.

1278-14: After 45 minutes of growth, the chemical garden is finished. If protected from vibrations, it may last for several days before collapsing into tiny fragments.

1278-25: crystals.

1278-15: When they reach the sides of the aquarium, the osmotic growths attach themselves to it and develop, offering an insight into the intimacy of their interior space.

1278-27: Calcium chloride crystals.

1278-16: Start of the growth of cobalt chloride. The hatching of the bubble, formed by the air initially imprisoned in the aggregate, appears to play a decisive role in the rest of the process. 1278-17: Unfortunately, the bubble is too large and quickly detaches itself, thus interrupting the growth of a large tube. 1278-18: This is quickly replaced by filaments, the much faster growth of which is also more dispersed and less predictable.

Potassium

hexacyanoferrate

1278-26: Manganese sulphate crystals.

1278-28: Silence! Life creation experiment in progress... The skills of patience, dexterity and ingenuity must be deployed to obtain the desired compositions since the scales are so small and potential disturbances are so numerous. 1278-29: Observation: one of the keys to the scientific approach. This is the moment when the researcher's reasoning and creativity intervenes. 1278-30-31: Two typical templates from the French and English versions of StĂŠphane Leduc's books. 1278-32: Osmotic productions of all sorts

(mushrooms, madreporaria, efflorescence, annelida, etc.) obtained by StĂŠphane Leduc and reproduced in the English version of his book. 1278-33: Tubular and filiform growths of copper sulphate (close-up). The influence of air bubbles produced by the degassing of the solution is particularly visible. 1278-34-35: The exuberant growth of iron chloride (III) gives rise to some of the most evocative forms. 1278-36: Microscopic crystallisations of calcium chloride, invisible to the naked eye, form the wall of the osmotic cell which has grown around the original fragment. 1278-37: Surprising symmetries may be obtained with cobalt chloride crystals, the colours of which are also almost as uncontrollable as they are duplicable. 1278-38: Cobalt chloride crystals. 1278-39: Nickel sulphate crystals. 1278-40-41:Osmotic productions by StĂŠphane Leduc. 1278-42: Hollow tube of fulgurite produced by lightning striking the sand.