Henry Alex Miers

“ The main conclusion of my lecture was that, having been led by analogy to compare the growing crystal with the growing plant, one finds the growth and life of the crystal to be totally unlike the growth and life of any organism. Its life is only an unchanging persistence without the display of any struggle for existence, any movement, any adaptation, or response to environment; its growth is only the addition of new material on the surface of the old, without assimilation, so that the crystal remains uniform and increases in size; there is no distinction of any one part from any other ”

“ Do not some of the standard methods which are familiar in the descriptions or criticisms of scientific discovery, such as ‘reasoning from the known to the unknown’, ‘the adoption of a working hypothesis’, ‘the scientific use of the imagination’, often resolve themselves on analysis into the simple process of being struck by an analogy and being led by it to adopt an explanation or to try an experiment suggested by it? ”

“ When I delivered my own inaugural lecture I had no means of making visible to an audience the astonishing features of crystal growth. Beautiful effects may easily be witnessed by anyone with a few drops of common solution and a magnifying glass, yet I believe that they are witnessed by comparatively few persons. ”

“ Now, Miss Isaac and I have found in the course of our researches that, as the solution becomes stronger and stronger—say, by the evaporation of some of its water, it continues to be in the ordinary state of supersaturation in which it does not crystallize save by inoculation with a germ of solid alum crystal, but at last it suddenly reaches a condition in which it can crystallize spontaneously, and at this moment it is enough to stir or shake the solution, and you will at once witness the birth of thousands of tiny crystals which appear as a cloud in the liquid and begin to grow rapidly. ”

“ If we imagine the coalescence of atoms to form a crystal to be due to their mutual attraction, it is very reasonable to suppose that they will get as close together as is possible, and therefore that the ways of close packing are the ways of crystal structure. The theory therefore suggests a reason for the growth as well as for the shape of a crystal. I may remind you that the bee’s cell itself, which is in the world of life the thing that most nearly resembles crystalline structure, is due to this same principle of close packing ”

“ I have said that the frontier problems in science are interesting; and that this is true not only of the events that take place when different bodies meet, but in another and more general sense. The most interesting and fruitful problems are those which deal with the borderland between two sciences, when the difficulties of the one are enlightened by the experience of the other, or when the same problem is looked at from two different sides. ”

“ I have many times noticed that when the appropriate crystal is introduced into a supersaturated solution, which is not strong enough to crystallize spontaneously, it may cause crystals to grow not only in actual contact with itself, but at some little distance in its neighbourhood. If this be so, then the crystallizing force, the power of propagating crystal growth, is not merely a frontier problem, but can be exercised through the liquid to a distance. If I try to picture to myself what is happening, I must again have recourse to analogy ”

“ Remember that when we say we know how the particles of a crystal are arranged we really know nothing about their nature, and can only represent them by spheres, or solid figures, or cells, or even points, in order to get a representation of their arrangement. ”

“ Science grows on the acquisition of new knowledge and we must not hesitate to grasp it where we can. There is a danger lest the formulation of the methods of science may deter the inquisitive student from seeking knowledge wherever it is to be found, and make him believe that it is only by the orthodox processes of reasoning based upon a lifetime of training that he is to discover anything new. Rather let him be encouraged to seek any resemblance or analogy that may point a way in the gloom. ”

“ One is naturally led to imagine that before any solution begins to crystallize in the solid form it passes into this liquid state, and that the particles have begun to set themselves and all to face the same way before they begin to cohere and to build themselves into a solid. But so far as I know there is no evidence in favour of this suggestion—a solution before solid crystals begin to appear does not behave like a liquid crystal, but remains an ordinary solution up to the last moment when new crystals are born in it or are started by inoculation with a crystal germ. ”

“ I pointed out, I remember, that these delicate forms are, like the frost patterns on a window-pane, really expressions of the crystalline shape and symmetry of the mineral; each mineral consists of crystals, and therefore has its own peculiar crystalline shape which is one of its inherent properties; moreover, this persists unchanging through the ages, and under all conditions, and is in no way dependent upon the environment in which the mineral is situated. ”

“ And yet we know that the particles of matter, whatever they may be, are really in lively movement. Is it not possible that in order to get a correct understanding of the growth of a crystal we should take account not only of the positions, but of the movements, of its particles? Without some knowledge of these we are not able to approach the problem, or to ascertain how a crystal either of nitrate of soda or of Iceland spar draws the nitrate of soda out of the solution and makes it grow into a solid. ”

“ Neither does it make any difference if the crystal fragment has been kept for years or even centuries; it will, when supplied with nourishment from the appropriate solution, heal itself and continue to grow as though the process had never been suspended. In a sense it is immortal, for, if not destroyed, it never loses the mysterious power of growth, and is therefore more imperishable than any seed or germ of life. ”

“ If you wish to understand a plant or an animal it is not enough to study dried specimens or specimens in spirits, but to watch the living organisms growing under natural conditions; and in the same way it is surely worth while to study the growing crystal surrounded by the solution which feeds it, and even to make under these conditions the measurements and observations which are usually made upon crystals only after they have been taken out of the solution and have ceased to grow. ”

“ For, after all, when after making physical experiments upon the solid crystal and studying its action upon heat and light we are led to speculate upon the manner in which it is constructed, we must not forget that it grew, and that the material was laid down under conditions which we can only understand by studying what happens on the surface as it grows. ”

“ We can only picture these liquids as consisting of particles which, while they are free to move in all directions, always continue to face the same way, like a group of dancers who in all their evolutions continue to face the audience, instead of turning as they move. When the mechanism which renders possible this remarkable behaviour is better understood, we may be sure that it will bring about a better understanding of the manner in which a solid crystal is constructed. ”

“ So far from regarding the growth of a crystal as of no further importance after it has been proved to be quite different from the growth of a plant, we must still think of it as one of the most interesting and mysterious events, and the one through which we may hope to get the clearest insight into the nature of the crystal itself. ”

“ Imagine a pond covered by a number of such groups of skaters; the manner in which they will fit in, and have to arrange themselves, will depend both upon the dimensions and the rhythm of their curves, and they may even interlace and become part of one great figure system covering the whole pond. May not the growth of a crystal be something of this sort? ”

“ Those who are attracted to his Laboratory probably come because they have some natural taste for the subject; he finds it a pleasure to devote his time to them; while his vacations and the conditions of Oxford life give him unique opportunities for his own researches.
It is true that those who have most leisure not infrequently waste most time. It is true also that the custom of Oxford is to burden her students and scholars in addition to their teaching, with the conduct of affairs which could be managed as well by persons specially appointed for the purpose. ”

“ It is, of course, well known that if a crystal, say of alum, is placed in a weak solution of alum it is dissolved, and only has the effect of making the solution stronger, but that at last a stage is reached at which the solution becomes ‘saturated’ and can dissolve no more, just as a stage is reached at which a soaking sponge will hold no more water. ”

“ Still it is also certain that to those who enter into the genius of the place, and are animated by the spirit of Learning, Oxford is prodigal of opportunity, and enables them to live the Academic Life in a way which is scarcely possible elsewhere. ”

“ The one theory may be found to fit the facts and the other may be condemned; but without some analogy as a guide how are such theories to be devised? What we require in science are continual stimuli to start us on new experiments, new observations, and new ideas, and prevent us, especially those who are teachers, from constantly repeating the old ones.
I shall be satisfied if the present lecture is regarded as a plea for the use of reasoning from analogy, and as an illustration of its value. ”

“ But why they do not begin to coalesce as soon as the liquid is supersaturated it is difficult to say. We have to conceive the alum solution as made up of moving particles of alum and of water, and it may be that the particles are constantly coalescing into minute groups, but as rapidly being broken up again, until a moment arrives at which the alum particles are sufficiently dense to cohere permanently; but how they attract one another and arrange themselves into the wonderful structure which makes a crystal, of this we are entirely ignorant. ”

“ You will find, I think, that the scenes of the most interesting events in Nature are generally those places where different things come into contact and where there is consequently stir and action; where two substances meet to form a new chemical compound; where two bodies touch and react upon each other; at the surface of a solid or a liquid ”

“ If the growth of a crystal is really the coming together of vibrating particles which cohere because they are in tune with one another and so enter into a partnership like that of the dancers or the figure skaters, then is it not possible that we may be able to communicate these vibrations to a supersaturated solution, which is so densely crowded that it is ready to crystallize, by some other means than by inoculating it with the appropriate crystal? ”

“ I think it will be found that these problems of crystal growth are of this borderland nature. And such problems can only be satisfactorily attacked by those who are more than mere specialists and can be led by the experience or the analogies of other sciences.
I said that I should like to regard this lecture as an attempt to justify the value of analogy. We poor specialists grope within the confines of our own science, and what little advance we make is made in part by the light we borrow from the other sciences. ”

“ Moreover, it was the analogy which prompted the experiment. To detect an analogy, to test it, and to find that it cannot be maintained, may be as useful an addition to knowledge as the establishment of a real causal relationship: it has had the effect of setting the worker on to new experiments or observations, and every such step is necessarily an advance. The conscientious search for one thing almost invariably leads to the discovery of another ”

“ In these days of increasing specialization what we need is to interest in our own problems, not only those who are tilling the same fields with ourselves, but even more, those who live on the other side of the fence which surrounds us: to call to them across the frontier, to seek their advice and assistance and the benefit of their experience. ”

“ This is one of the great advantages of a University, that workers and thinkers in different subjects are brought together and can make their difficulties known to each other. The connecting links between them are the analogies which they perceive and which excite an interest that they would not otherwise feel in each other’s work. ”

“ But there is no need to be ashamed, for the discoveries only come to those who have the eyes to see, or the knowledge which enables them to remember a resemblance, and who have further the intellectual power to make use of it. ”

“ Now, when a perfectly clean crystal of Iceland spar is immersed in a strong solution of nitrate of soda, although it is not dissolved by the liquid itself and therefore cannot crystallize out of it, the Iceland spar actually continues to grow, and becomes enveloped by the nitrate of soda so as to form what is apparently a single crystal. ”

“ All the devices which I have quoted for picturing to ourselves the architecture of a crystal I would regard as merely models representing something that may be really quite different. But I venture to suggest that the time has come when we should make use of moving and not stationary models. ”

“ One need not go further than a spinning top for an illustration of stability due to movement, and there is nothing unreasonable in the suggestion that the rigidity of a crystal structure may be due to the motion of its parts. ”

“ In the case of living things, we know that growth takes place by internal processes and not only by new material added on the surface. How much easier, then, should it be to study the growth of a crystal when we have found that it is only a surface activity, and does not involve internal changes? ”