Chambers's Journal of Popular Literature, Science, and Art, No. 701

Kissing with golden face the meadows green,
Gilding pale streams with heavenly alchemy,

But I told myself that I really must make a beginning now, as I stood in the milliner's show-room, somewhat dolefully contrasting my appearance with that of the elegant-looking beings around me; wondering whether Philip would wish me to look like them, and in that case, whether it would be possible to make me do so.

I had been striving so earnestly and anxiously to make myself worthy to be his companion, and it had seemed of so little consequence what I looked like during his absence, beyond being attired with the dainty neatness befitting a gentlewoman, that I now appeared quite behind the times. I suddenly began to realise that I had carried my disregard of pretty things too far; and was seized with a desire to try what extraneous aid could do for me.

I anxiously studied my face and figure in the large glass, and then those of the obliging shopwoman, who displayed an endless assortment of pretty things for my selection. She was about my own age, and possessed no greater natural advantages than I myself could boast of; and yet how very different was the general effect of her appearance; how dowdy I looked beside her. Yes; Lilian was quite right; 'dowdy' was the proper word for me, from head to foot.

A little shyly and consciously, I ventured out of my shell, and appealed to the shopwoman for assistance, taking her so far into my confidence as to confess a desire to be modernised and made more attractive.

She displayed more interest in the matter than I had ventured to hope for; and we gravely discussed my capability of improvement. But I found that the complications would be so many, and the changes in the way of adaptation of hair, figure, &c. so endless, that I presently began to grow very impatient; and when she said something about the possibility of the present fashion only lasting another two months, I gave it up in despair. If I were quite sure it would serve for the rest of my life, I would go through it all; but for the fashion of an hour; no! I would be content with a simply made dress or two, and depend upon my own taste for the finishing touches. Some of my mother's old point, and a crimson bow or two for the pretty gray dress, and amber with the black silk, and such like, I trusted might please Philip's artistic taste as well as though I were in the latest fashion. And I pleased myself with the remembrance that he used to admire my method of dressing my hair in large coils round a comb; saying that it suited my head and Spanish style of face. 'Spanish! Yes; that certainly was the word,' I told myself, dwelling pleasantly upon the one only compliment I could recollect having received from Philip.

I tried to satisfy myself this way; nevertheless I was a little out of spirits at finding myself so different from other women whom I met as I walked through the park on my way to the railway station, and whom I scanned with curious critical eyes, trying to understand the intricacies of their toilets, and failing to obtain anything more than a general impression that the tout ensemble was very effective. The home dress might be compassed; but how if it turned out that Philip wished his wife to look picturesque and attractive out of doors – not in Mrs Trafford's style, but in Lilian's more refined way of being in the mode? I would take Lilian into my confidence at once, and she would help me. That very night I had determined to make the truth known to her and to Mrs Tipper; and after it was once known, the dress question could be entered upon.

THE STORY OF THE PRISM

When we see the brilliant colours reflected by the glass lustres and chandeliers which are now so commonly used for decorative purposes, we seldom bestow a thought upon them, regarding them as things too common, perhaps too trivial to be worthy of any particular attention. We are content to know that a triangular piece of glass will exhibit certain bright colours – they look very pretty, and it does not matter much how they happen to be there. This is the common way of dealing with the natural phenomena which meet us at every turn in this wonderful world in which we live. The progress of civilisation, with all its triumphs of Science and Art, would indeed have been slow, if not altogether at a dead-lock, if every one had been content to treat such matters in this summary fashion. But happily, this has not been the case, for certain intellectual giants have from time to time arisen, who have grappled with these things, and have devoted their lives to their investigation.

Such a one was Sir Isaac Newton, who just about two centuries ago, with rough appliances fashioned by his own hands, inquired into the meaning of the colours to which we have just alluded. We cannot do better than quote his own words, from a letter which he addressed to the Royal Society in 1672; for his statement is so clear that a child can easily understand what he means. 'I procured me a triangular glass prisme,' writes he, 'to try therewith the celebrated phenomena of colours. And in order thereto having darkened my chamber and made a small hole in my window-shuts to let in a convenient quantity of the sun's light, I placed my prisme at his entrance, that it might be thereby refracted to the opposite wall.'

He goes on to say how surprised he was to find that the ray of light, after passing through the prism, instead of being thrown upon the wall in the form of a round spot, was spread out into a beautiful coloured ribbon; this ribbon being red at one end, and passing through orange yellow green and blue, to violet at its other extremity. Upon this experiment is founded the theory of colour, which with few modifications, still remains unquestioned.

It was not until the beginning of the present century that this experiment of Newton's (repeated as it had doubtless been in the meantime by many philosophers) was found by Dr Wollaston to possess certain peculiarities which defied all explanation. He found that, by substituting a slit in the shutter of the darkened room for the round hole which Newton had used, the ribbon of colour, or spectrum as it is now called, was intersected by certain dark lines. This announcement, although at the time it did not excite much attention, led to further experiments by different investigators, who, however, vainly endeavoured to solve the meaning of these bands of darkness. It was first observed by an optician of Munich that they never varied, but always occupied a certain fixed position in the spectrum; moreover he succeeded in mapping them to the number of nearly six hundred, for which reason they have been identified with his name, as 'Frauenhofer's lines.'

In 1830, when improved apparatus came into use, it was found that the number of these lines could be reckoned by thousands rather than hundreds; but their meaning still remained a puzzle to all. By this time Newton's darkened room with the hole in the 'window-shuts' had been, as we have just said, greatly improved upon. The prism was now placed in a tube, at one end of which was a slit to admit the light, while the retina of the observer's eye received the impression of the spectrum at the other end. This is the simplest form of the instrument now known as the spectroscope, and which is, as we have shewn, a copy in miniature of Newton's arrangement for the decomposition of white light into its constituent colours.

We must now go back a few years to record some experiments carried out by Herschel, which, quite independent of the spectroscope, helped others to solve the problem connected with the dark lines. He pointed out that metals, when rendered incandescent under the flame of the blow-pipe, exhibited various tints. He further suggested that as the colour thus shewn was distinctive for each metal, it might be possible by these means to work out a new system of analysis. A familiar instance of this property in certain metals may be seen in the red and green fire which is burned so lavishly during the pantomime season at our theatres; the red owing its colour to a preparation of the metal strontium, and the green in like manner to barium. Pyrotechnists also depend for their tints not only upon the two metals just named, but also upon sodium, antimony, copper, potassium, and magnesium. Wheatstone also noticed the same phenomena when he subjected metals to the intense heat of the electric current; but it was reserved for others to examine these colours by means of the spectroscope. This was done by Bunsen and Kirchhoff in 1860, who by their researches in this direction, laid the foundation of a totally new branch of science. They discovered that each metal when in an incandescent state exhibited through the prism certain distinctive brilliant lines. They also found that these brilliant lines were identical in position with many of Frauenhofer's dark lines; or to put it more clearly, each bright line given by a burning metal found its exact counterpart in a dark line on the solar spectrum. It thus became evident that there was some subtle connection between these brilliant lines and the dark bands which had puzzled observers for so many years. Having this clue, experiments were pushed on with renewed vigour, until by some happy chance, the vapours of the burning metals were examined through the agency of the electric light. That is to say, the light from the electric lamp was permitted to shine through the vapour of the burning metal under examination, forming, so to speak, a background for the expected lines. It was now seen that what before were bright bands on a dark ground, were now dark bands on a bright ground. This discovery of the reversal of the lines peculiar to a burning metal, when such metal was examined in the form of vapour, led to the enunciation of the great principle, that 'vapours of metals at a lower temperature absorb exactly those rays which they emit at a higher.'

To make this important fact more clear, we will suppose that upon the red-hot cinders in an ordinary fire-grate is thrown a handful of saltpetre. (This salt is, as many of our readers will know, a chemical combination of the metal potassium with nitric acid – hence called nitrate of potash, or more commonly nitre.) On looking through the spectroscope at the dazzling molten mass thus produced, we should find that (instead of the coloured ribbon which the sunlight gives) all was black, with the exception of a brilliant violet line at the one end of the spectrum, and an equally brilliant red line at the other end. This is the spectrum peculiar to potassium; so that, had we not been previously cognisant of the presence of that metal, and had been requested to name the source of the flame produced, the spectroscope would have enabled us to do so without difficulty. We will now suppose that we again examine this burning saltpetre under altered conditions. We will place the red-hot cinders in a shovel, and remove them to the open air, throwing upon them a fresh supply of the nitre. We can now examine its vapour, whilst the sunlight forms a background to it; when we shall see that the two bright coloured lines have given place to dark ones. This experiment will prove the truth of Kirchhoff's law so far as potassium is concerned, for the molten mass first gave us the bright lines, and afterwards by examining the cooler vapour we saw that they were transformed to bands of darkness; in other words they were absorbed. (In describing the foregoing experiment, we have purposely chosen a well-known substance, such as saltpetre, for illustration; but in practice, for reasons of a technical nature, a different form of potassium would be employed.) Kirchhoff's discovery forms by far the most important incident in the history of the spectroscope, for upon it are based the new sciences of Solar and Stellar Chemistry, to which we will now direct our readers' attention.

The examination of the heavenly bodies by means of the spectroscope has not only corroborated in a very marvellous manner the discoveries of various astronomers, but it has also been instrumental in correcting certain theories and giving rise to new ones. The existence of a feebly luminous envelope extending for hundreds of thousands of miles beyond the actual surface of the sun, has been made evident whenever an eclipse has shut off the greater light, and so permitted it to be viewed. The prism has shewn this envelope, or chromosphere as it is called, to consist of a vast sea of hydrogen gas, into which enormous flames of magnesium are occasionally injected with great force. (We need hardly remark that these facts are arrived at analogously by identifying the absorption lines with those given by the same elements when prepared artificially in the laboratory.) This chromosphere can, by the peculiar lines which it exhibits in the spectroscope, be made manifest whenever the sun itself is shining.

The foregoing discovery has given astronomers the advantage – during a transit of Venus – of viewing the position of the planet both before and after its passage across the sun's disc; for it is evident that the presence of an opaque body in front of the chromosphere will cut off the spectral lines in the path which it follows; so that although the planet is invisible its exact place can be noted. From a comparison of these lines with those that can be produced in the laboratory, it is rendered probable that no less than thirteen different metals are in active combustion in the body of the sun. From certain geological appearances, it is conjectured that our own earth was once in this state of igneous fusion, and although our atmosphere is now reduced to a few simple elements, it must once have possessed a composition as varied as that of the sun. As it is, the air which we breathe gives certain spectral lines. These are much increased in number when the sun is low, and when therefore it is viewed through a thicker medium. In this case the blue and green rays are quickly absorbed, while the red pass without difficulty through the denser mass of air, thus giving the setting sun his blood-red colour. It will now be readily understood how, by means of the spectroscope, the existence of atmosphere in the superior planets can be verified. What a world of conjecture is thus opened out to us! for the existence of atmosphere in the planets argues that there are seas, lakes, and rivers there subject to the same laws of evaporation as those upon our own earth. And if this is so, what kind of beings are they who inhabit these worlds? The moon shews no trace of atmosphere, so that we may assume that if there be living beings there, they must exist without air and without water. The lines given by the moon and planets being in number and position identical with those belonging to the solar spectrum, is a further proof, if any were needed, that their light is borrowed from the sun.

The varied colours of the fixed stars may be assumed to be due (from what we have already stated with regard to metallic combustion) to their chemical composition; and the spectroscope, by the distinctive lines which it registers, renders this still more certain. Their distance from us is so vast, so immeasurably beyond any conception of space that we can command, that the detection of their composition is indeed a triumph of scientific knowledge. It has been calculated that if a model of the universe were made in which our earth were depicted as the size of a pea, the earth itself would not be one-fifth large enough to contain that universe.

If we marvel at the extraordinary skill which has brought these distant spheres under command of an analytical instrument, we must wonder still more when we are told that the spectra of these bodies can be brought within range of the photographic camera. This has lately been done by the aid of the most complicated and delicate mechanism; the difficulty of keeping the image stationary on the sensitive collodion film during the apparent motion of the stars from east to west, having only just been surmounted. This power of photographing the spectrum is (as we hinted in a recent paper on Photographic Progress) likely to lead to very great results, for the records thus obtained are absolutely correct, and far surpass in accuracy the efforts of the most skilful draughtsman. It must be understood that in all these researches the spectroscope is allied with the telescope, otherwise the small amount of light furnished by some of the bodies under examination would not be enough to yield any practical result.

The clusters of matter which are called nebulæ, and which the most powerful telescopes have resolved into stars, are shewn by the prism to be nothing but patches of luminous gas, possibly the first beginnings of uncreated worlds. Comet-tails are of the same nature, a doubt existing as to whether their nuclei borrow their light from the sun or emit light of themselves. We may close a necessarily brief outline of this part of our subject by stating that it is possible that the spectroscope may some day supplant the barometer, more than one observer having stated that he has discovered by its aid signs of coming rain, when the latter instrument told a flattering tale of continued fine weather.

We have merely shewn hitherto how the spectroscope is capable of identifying a metal; but its powers are not limited to this; for by a careful measurement of the length of the absorption lines, a very exact estimate of the quantity present can be arrived at. This method of analysis is so delicate that in experiments carried on at the Royal Mint, a difference of one ten-thousandth part in an alloy has been recognised. Neither must it be supposed that the services of the spectroscope are confined to metals, for nearly all coloured matter can also be subjected to its scrutiny. Even the most minute substances, when examined by the microscope in conjunction with the prism, shew a particular spectrum by which they can always be identified. Nor does the form of the substance present any difficulty in its examination, for a solution will shew the necessary absorption bands. Blood, for instance, can be discovered when in a most diluted form. To the physician the detection of the vital fluid in any of the secretions is obviously a great help to the diagnosis of an obscure case. But in forensic medicine (where it might be assumed that this test would be of value in the detection of crime) the microscope can identify blood-stains in a more ready manner.

The simple glass prism as used by Newton, although it is the parent of the modern spectroscope, bears very little resemblance to its gifted successor. The complicated and costly instrument now used consists of a train of several prisms, through which the ray of light under examination can be passed by reflection more than once. By these means greater dispersion is gained; that is to say, the resulting spectrum is longer, and consequently far easier of examination. A detailed description of the instrument would be impossible without diagrams, but enough has been said to enable the reader to understand theoretically its construction and application.

It will be understood that we have but lightly touched upon a phase of science which is at present quite in its infancy. It is probable that many more remarkable discoveries will in course of time be due to the prism. Already, within the past twenty years, four new metals have by its aid been separated from the substances with which they were before confounded; and although they have not at present any commercial value, we may feel sure that they have been created for some good purpose not yet revealed to us. There are signs that the spectroscope will some day become a recognised adjunct to our educational appliances. It is even now included under the head of Chemistry in the examination of candidates for university honours, and there is no doubt that it will gradually have a more extended use. Many years hence, when generations of School-Boards have banished ignorance from the land, the spectroscope may become a common toy in the hands of children, enabling them to lisp:

Twinkle, twinkle, little star;
We know exactly what you are.

THE ROMANCE OF A LODGING

IN TWO CHAPTERS. – CHAP. I

'Where to, ma'am?' inquired cabby as he opened the door of his vehicle to a lady and her son who had just arrived by the evening train at Victoria Station.

'I want apartments somewhere in the neighbourhood of Chelsea; drive on until you find them: they are procurable, I suppose?' the lady replied as she took her seat.

'I do hope we may find a lodging,' she remarked to her companion, after they had been driving what appeared to her a very long time. The lad made no reply, being of a phlegmatic temperament, that finds speech an exertion unless distinctly necessary.

The lateness of the hour together with the influx of visitors, owing to the London season being then in full swing, made the search a difficult one; they were about to give up its continuance and go to an hotel, when the cabman good-naturedly proposed making one more attempt, and drove down a fresh street. Stopping at a baker's shop on the way, he invited the assistance of those serving, as it was growing too dark to discern the cards of advertisement.

They directed him to a private house in a street adjoining, but added: 'The chances are they are let; still you might just as well try, as Mrs Griffiths has a yearly lodger who allows her to sublet sometimes; perhaps he is away now.'

'Shall we chance it, ma'am?' inquired the cabman.

'Do; I am so weary. She may be able to give us a corner for the night at least.'

When they reached the house, Mrs Griffiths – late cook in a nobleman's family, who had married the footman – appeared, and in answer to the appeal, asked hesitatingly: 'For how long?'

'We should take them for a week of course,' said the lady.

'I cannot let for so long,' she replied, after a brief calculation; 'but I can accommodate you for a couple of days, if you please; that will give you time to find other rooms.'

'Thank you very much,' said the wearied traveller gratefully, as she followed the landlady into a good-sized room on the right of the entrance-hall, and begged for lights and tea as soon as Mrs Griffiths could make it convenient to send them.

'How very fortunate we are to have found a night's lodging,' she said to the lad, who now joined her. 'I think I see an easy-chair in that corner; what a comfort!' and she sat down to rest, removing some of her heavy wraps as she spoke. 'Now at least we shall have breathing-time to consider what is best to be done after your examinations are over. I can go in search of rooms to-morrow while you are at them. I wish she would hasten with the light and tea; this darkness is oppressive. Where are you, Fred?'

'Here,' he replied, from the opposite side of the room. 'Can I do anything for you? I've seen to the luggage and paid the cabman, and now am quite ready to do justice to some tea.'

They were soon put out of their discomfort by the entrance of the landlady, bearing a handsome lamp which gave a brilliant light.

'I've brought you my gentleman's lamp, ma'am; he is away just now; that is why I have been able to accommodate you; for he's most obliging, and don't mind my letting his rooms – this one and the one inside behind the folding-doors, together with the one I have given the young gentleman up-stairs, which belongs to his man-servant. May I ask what name, ma'am?'

'Mrs Arlington; and the young gentleman is my son.'

Mrs Griffiths glanced at the tall elegant woman in widow's weeds, and thought to herself: 'She looks more fit to be his sister than his mother; and is a sweet-looking lady anyway, whoever she is;' and she was glad she had taken her in and her son, if such he were. And then she bustled out of the room to prepare their meal.

As soon as they were alone, Mrs Arlington gazed around the room indifferently. It was of the usual stamp of lodging-house apartment, furnished according to the taste and means of those who take to letting for a livelihood. A dismal horse-hair suite were the chief articles of furniture, supplemented by others which stood out in contrast against the horse-hair background – a good piano, an harmonium, a bookcase with glass doors filled with a choice selection of the best works, and an easel. On the walls hung several good paintings, one of which was the portrait of a beautiful young girl.

'Some artist must live here, I imagine,' said the lad, as he went from picture to picture examining them, finally stopping before the portrait of the young girl, that hung immediately over the chair in which Mrs Arlington sat.

'I daresay,' she replied weariedly, as though it were a speculation which could not possibly concern her; and too glad of repose to be roused to any sense of curiosity upon the subject.

'Just look at this, mother; it is so pretty.'

'I cannot, Fred; I am too exhausted to turn round. I cannot possibly think of or look at any thing until I have had a cup of tea. – Ah! here it comes. Go and pour it out for me, and never mind the picture. But I forget. I am unfeeling and unnatural to tell you not to mind, for you are just at an age when young girls are beginning to possess a powerful attraction for you; but you must put the pleasing delusions out of your head until you have passed your examination for Sandhurst; that is the move-in-chief towards which all your energies must now be directed. I long to see your poor father's wishes fulfilled; and shall not feel quite contented until you are gazetted into the army; then my trust will have been accomplished. How many years is it now, Fred, since you first became my child?'

'Ten.'