"Fourth State of Matter." It is called also "Radiant Matter," for a reason which shall presently be given.

As we have already seen, the ordinary properties of a gas depend on the state of constant collision of its molecules and their consequent continual change of path. Therefore if we reduce their number within a given enclosed space to the very great extent which has just been mentioned, it follows that those ordinary properties must change, because the number of collisions will be much smaller and the change of path much rarer. The average distance traversed by molecules of air at the ordinary atmospheric pressure without a collision, called their "mean free path," is an almost inconceivably small fraction of an inch. At the exhaustions employed in Mr. Crookes' experiments, the mean free path is extended to several feet, and being consequently relieved from the interference with their motion caused by the enormous number of collisions they generally have to encounter, the molecules are able to move in straight lines (hence the appellation radiant), which though always their tendency, is rendered quite impossible to them under ordinary conditions. What is studied therefore in these researches into the ultra-gaseous state is (so far as is possible in the case of portions of matter too small to be brought under the direct cognizance of our senses by any artificial means whatsoever), the behavior of the average individual molecule, instead of the behavior of the whole mass of molecules; and these difficult investigations are car ried on by the aid of that mysterious agent which has been compelled in so many ways to do man's work, and of whose nature he is nevertheless still so ignorant-electricity.

In order to understand the means employed, we must return for a moment to the consideration of matter still retaining the ordinary properties of the gaseous state, though it is rarefied to some extent; and, for the sake of precision, let us take the case of air, and follow it through its experiences in a vacuum tube. A vacuum tube is a glass tube or vessel of any shape, from which the air with which it was originally filled has been pumped out, until

the required stage of exhaustion is reached. Metal terminals connected with an induction-coil for producing a powerful electric spark, are introduced into each end of the tube,* and when the electric current is set up and while it continues, the spark passes through the tube in the form of a beautiful flickering light, opalescent in the case of air, but varying in color with the nature of the gas employed and with the degree of exhaustion. In air at the ordinary density, the spark would either not pass at all (for air is a non-conductor), or if it were very powerful indeed, it would burst through with an explosive discharge like a miniature flash of lightning, very probably shattering the tube on its road. In moderately exhausted tubes then, the discharge is seen as a flickering line of light. In tubes exhausted to a pressure equal to about two and a half millionths of an atmosphere, the discharge becomes stratified, luminous layers alternating with dark layers, and the glow from the positive pole is separated from that of the negative pole by a dark space known as "Faraday's,' "Faraday's," because he was the first to observe it, while a second very much smaller dark space surrounds the negative pole itself. With increasing exhaustion this second dark space grows larger and larger till at length it fills the whole tube, and it is at this stage that the residual gas loses the properties which ordinarily distinguish gaseous matter, and enters upon the Fourth or "Radiant" state. The meaning of the stratified discharge is thus explained by Mr. Crookes :

"If at some time when the stream of traffic

[in a frequented thoroughfare] runs almost equally in both directions, we take our stand

at a window from which we can overlook the passing crowd, we shall notice that the throng on the footway is not uniformly distributed, but is made up of knots-we might almost say

In some of Mr. Crookes' experiments in high vacua, the electrodes (poles) were on the outside of the glass tube instead of being allowed to enter it, a modification introduced in order to prove that the effects observed were not due to minute metallic particles torn off the electrodes by the passage of the electric discharge, but to the residual gas itself,

+ Presidential Address to the Institute of trician, January 16th, 1891. Electrical Engineers, reported in the Elec

"Instead of observing moving men and

blocks-interrupted by spaces which are comparatively open. We may easily conceive in what manner these knots or groups are formed. Some few persons walking rather

more slowly than the average rate slightly retard the movements of others, whether travelling in the same or in an opposite direction. Thus a temporary obstruction is created. The

passengers behind catch up to the block and increase it, and those in front passing on unchecked at their former rate, leave a comparatively vacant space. If a crowd is moving all in the same direction, the formation of these groups becomes more distinct. With vehicles in crowded streets, the result, as

every one may have remarked, will be the same. Hence mere differences of speed suffice to resolve a multitude of passengers into alternating gaps and knots.

The effect of the electric influence on

the molecules is therefore directive, and the dark spaces are indicative of those parts of their path where the fewest collisions take place. This enables us to perceive the meaning of the enlargement of the dark space round the negative electrode. It represents the increasing mean free path of the molecules with increasing degrees of exhaustion, and when it fills the whole tube then throughout the length of the tube there are practically no collisions between the molecules at all; they travel in straight lines perpendicular to the surface of the negative electrode. It may well be asked, however, how can this or indeed the presence of the mole cules be known if their luminous track is wiped out? And the reply is that by artificial means they can be made to discover themselves, and that in a very beautiful manner. All readers are to

women, suppose we experiment on little particles of some substance such as sand, approximately equal in size. If we mix the particles with water in a horizontal tube and set them in rhythmical agitation, we shall see very similar results, the powder sorting itself with regularity into alternate heaps and blank spaces. If we pass to yet more minute substances, we observe the behavior of the molecules of a rarefied gas when submitted to an induction current. The molecules here are free of course from any caprice, and simply follow the law I seek to illustrate, and though originally in a state of rampant disorder, yet under the influence of the electric rhythm they arrange themselves into well-defined groups or stratifications; the luminosities show where arrested motion with concomitant friction occurs, and the dark intervals indicate

where the molecules travel with comparatively

few collisions."

some extent familiar with the phenomena of phosphorescence, and are aware that the peculiarity of phosphorescent substances lies in their capability of shining in the dark. Mr. Crookes has found that some bodies which are not phosphorescent under ordinary conditions, such as diamond, ruby, certain kinds of glass, and a rare earth called yttria, become so when placed in the which he uses in his experiments. By very highly exhausted vacuum tubes placing within the tube a phosphores cent screen, or rather one which becomes phosphorescent under the impact of the electrified molecules, their line of march is illuminated. It is so because the highly rarefied gas, instead of pressing equally in all directions as does dense, or only slightly rarefied gas, presses with greatly increased force in one direction-viz., perpendicularly to the surface of the negative electrode; and therefore if a screen made of appropriate material be placed in the path of the procession of molecules, it is so vehemently bombarded by these energetic little travellers that they set up in it an intense and rapid vibration which makes it for the time self luminous, the color with which it phosphoresces being dependent on the nature of the substance used, and being at a certain stage of exhaustion (different for different substances) exceedingly brilliant and beautiful. Nor is this the only way in which the presence and action of “radiant matter" can be detected. Many years ago Mr. Crookes invented a wonderful little instrument, which he called a radiometer, in appearance much like a miniature windmill, the vanes of which are enclosed in a bulb exhausted of air. It was at first sometimes called the "light-mill," because it acts as though the light repelled its little vanes, but a more accurate name would be the heat-mill, for the phenomenon is a thermal one, and as in all heat-engines. is due to inequality of temperature. The vanes of the radiometer are black on one side and bright on the other. The light passing through the glass bulb without sensibly warming it, falls on and is absorbed by the blackened surface of the vane. The black surface is thus slightly warmed, causing the molecules of the residual air to leave the surface

with a greater velocity than they fell upon it; the blackened face is thus kicked back by the molecules' rebound, and the motion is kept up owing to the dissipation of this increased molecular activity by the cooler surface of the glass bulb. A modification of this little instrument, the electrical radiometer, has been made to serve the purpose of investigation into some of the properties of radiant matter, which also by appropriate adjustments causes sharp shadows to be cast by objects placed in its path.

These wonderful researches, of which a slight outline has been given, reveal to us in fact a new world, where matter exists under conditions totally different from any with which we were cognizant before; but it is a "world which we can never enter, and in which we must be content to observe and experiment from the outside." Not a few of the socalled "practical" members of society would immediately rejoin," And what, then, is the use of knowing anything about it?" To these it may be replied that, though the direct result of scientific investigation is not always

"practical," indirect practical results are nearly sure to ensue. Mr. Crookes' researches in high vacua have been of the very greatest incidental use for industrial purposes, for it is owing to them that the means of procuring more perfect vacua have been so extraordinarily improved; and without this possibility not one of the many competing "incandescent" electric light bulbs, each excellent in its own way, could have been successful. This may, perhaps, to some extent satisfy the utilitarian cravings of those to whom science. is nothing more nor better than an ingenious purveyor to material needs. But there are others to whom knowledge is an end in itself, to whom a little clearer and better understanding of the universe to which they belong, a little deeper insight into the "many-colored wisdom" of the Creator, is reward sufficient for much labor. It is to such as these that the present short record of one of the most remarkable discoveries of modern days, the fruit of consummate skill and of years of the patient investigation of genius, will appeal.— Good Words.

WHEN the decease of Professor Tyndall was announced no fewer than six editors of magazines telegraphed to Professor Huxley for an article. Mr. Knowles was slightly quicker than the rest, and secured the prize.

THE January number of Poet-Lore (Boston, Mass.) contains extracts-to be continued in future numbers-from a series of unpublished letters of George Eliot. They are written between 1840 and 1842, and addressed to a Miss Lewis. Here is a quotation from one of them : "Have you, dear Patty, read any of T. Carlyle's works? He is a great favorite of mine, and I venture to recommend to you his 'Sartor Resartus.' His soul is the shrine of the brightest and purest philanthropy, kindled by the live coal of gratitude and devotion to the Author of all things. I should observe that he is not orthodox."

THE last number of the Eagle, a magazine supported by members of St. John's College,

Cambridge, contains some further details about Wordsworth's room, recently demolished in the course of alterations made in the kitchen. It appears that the window is still preserved, and that two fellows of the college have filled it with stained glass, bearing a memorial inscription. As usual, the obituary notices are prominent, among those here commemorated being C. E. Haskins, H. D. Darbishire, C. A. M. Pond, and L. Blomefield (Jenyns). A playful paper, which was found among Darbishire's Mss., entitled "Why We Talk," is also printed. A large number of his classical and philological books have been presented to the college library. Dr. Donald MacAlister contributes a German rendering of "Crossing the Bar," from which we quote the first stanza :

"Die Sonne sinkt, die Abendsterne glünn,

Ein heller Anruf fordert mich ins Meer; Sei mir gewährt es brause kein Gestöhn Am Hafenausgang wenn ich seewärts kehr'."

THE Publishers' Circular has issued its usual analytical table of books published in 1893. The total number, adding together new books and new editions, is 6382, being 128 more than last year. It would be interesting to compare the totals in the several classes, if one could place any reliance upon the principle of classification. Novels appear to have largely decreased-which is opposed to our personal experience; while juvenile books have increased

more than twofold. These two classes together make up nearly one-third of the whole. Taking a period of thirteen years, we find that theology has been declining steadily: in 1881, it was represented by 945 books, or 17 per cent of the total; last year by 533, or 8 per cent. There is also a notable decline in political and social economy (226 in 1880 and only 85 last year); and in scientific and illustrated works (452 in 1880 and only 123 last year). On the other hand, poetry is looking up, having increased from 93 in 1886 to 234 last year; while the fall in other classes is made up for by an enormous rise in miscellaneous (from 232 in 1881 to 1430 last year).

By the death of Mr. George C. Foulk toward the end of last year, at Miyanoshita in Japan, the Americans lose their best authority on Corea. He was in the United States Navy, and being on the Japan station learned Japan

ese and Corean. He was then transferred to be Naval Attaché to the United States Corean Legation. In the outbreak of 1884 he had a narrow escape of losing his life in Corea. His

observations on Corea are contained in a series of papers in the "United States Foreign Relations for 1885." Abandoning the navy, he married a Japanese wife and settled in Kioto, becoming Professor of Mathematics in the Doshisha University.

THE deaths are announced of Mrs. W. M.

Thackeray, the widow of the great novelist, and of Mrs. W. W. Story, wife of the wellknown sculptor and author.

WE hear that Miss Marie Corelli's "Romance of Two Worlds" has been translated into Hindustani, under the title of "Fisánái do-Jehan," and will be published early next month at Lucknow, which city still maintains its old reputation as a literary centre. The translator, whose work is a labor of love, is now engaged upon "Barabbas." This latter novel, we may add, has been very popular on the continent in its Tauchnitz edition; and versions of it will shortly appear simultane

ously in French, Italian, German, and Swedish.

THE first work of the late Professor Jowett's to appear after his death will be a reissue of his Notes and Dissertations on the Epistles to the Thessalonians, Galatians, and Romans, together with the essay on the Interpretation of Scripture, which originally appeared in Essays and Reviews. It will be in two volumes, edited and condensed by Professor Lewis Campbell, and will be published by Mr. John Murray.

MR JOSIAH FLYNT, a young American, who has already published some articles in the magazines upon the causes, career, and cure of the Tramp, is now engaged on a book treating the same subject at length, and giving in. dividual instances of tramp life and adventure.

MRS. NEWTON CROSLAND has written a pleasant volume of reminiscences in "Landmarks of a Literary Life" (Sampson Low & Co.), put together with remarkable clearness for an old lady of eighty, who can dimly remember the Sunday of Waterloo. Her recollections are of many kinds. In the drama she can just say she saw Miss O'Neill on the stage; but when seventeen or eighteen she beheld from the third row of the pit (then the favorite place of middle-class playgoers) the Shylock and Othello of Edmund Kean. At the opera she heard Malibran. She was acquainted with Lady Blessington, and dined at Gore House with Louis Napoleon when he had escaped from Ham. Of authors she has known Leigh Hunt, Douglas Jerrold, the Brownings, Mrs. Loudon, the Howitts, Miss Mitford, and others. As Mrs. Crosland is a believer in spiritualism, she naturally enough encouraged Mrs. Browning's strong leanings to a like faith, which her husband as naturally opposed:

"The last time I had seen the Brownings in England the conversation turned to the subject of the then recent spiritual manifestations which had been the talk of the town. Mrs. Browning was deeply interested in many things I had to tell her, her husband joining at first but little in the conversation between us. When, however, I offered to lend her a certain book on the subject, which she wished to see, he broke in, somewhat vehemently, begging I would do nothing of the kind, as he did not wish her mind to dwell on such things. I remember Mrs. Browning exclaim

ing rather warmly, 'Robert, my soul is my own,' though, with wife-like obedience, she yielded. But in Florence, with a smile on his face, Robert Browning asked me if I chanced to have that book with me, as now he had no objection to his wife reading it! I did chance to have it with me, and promptly fetched it from an adjoining room, and in two minutes, without being at all examined, it was slipped into the borrower's deep coat pocket."

Mrs. Crosland has creditably tried to avoid being prejudiced by her strong beliefs in spiritual phenomena, but probably she would not have thought so well of S. C. Hall had he not been an adherent; and the following is a naïve specimen of a lady's logic. She discoursed on the subject to Mr. Skinner, of Cambridge (who was never, as she thinks, Professor of Hebrew), and remarks: "He must have been a man accustomed to weigh evidence, for he listened attentively to all I said."

MISCELLANY,

TAKEN FROM LIFE.-Fiction is such an essential element in modern life that it is no easy matter to recall the time when the reading of novels was regarded as a very reprehensible business. It is to the novelist we turn now for our philosophy, our code of manners, and even our religion, and we must be exacting indeed if we cannot find an author to suit our taste among the embarrassment of riches at the disposal of any one who can subscribe to a circulating library. The immense general interest that is taken in novels is markedly apparent in the eager fashion in which any information concerning their making is received. One odd result of this enthusiasm is that certain persons have acquired an act ual celebrity as having been the " originals" of famous heroes, heroines, or villains that have thrilled us with their reality in this or that work of pure imagination.

In the early days of the novel, when Mlle. de Scudery was hailed a tenth muse on the strength of "Le Grand Cyrus," that belauded romance owed its chief success to the fact that it was but a thinly veiled study of Louis Treize and his brilliant court. Caps were fitted so incessantly that at last the enter prising authoress published a key, which was as fortunate as the original work. Less lucky was Mrs. Beecher Stowe when she tried the same experiment with "Uncle Tom's Cabin," probably because Americans were better

pleased to label their individual and personal enemies as the wicked torturers of the poor slave. With the notorious exception of the late Marquis of Queensberry, Thackeray seldom found his creations ticketed with living persons. Disraeli, on the contrary, took delight in sketching from nature, and if he did not see himself precisely as others saw him when he assumed the mantle of Vivian Grey or Endymion, his encounter with Professor Goldwin Smith showed that he was able enough to mirror other folks. Of the originals of Jane Austen's clear-cut studies we know and care to know nothing. The afterthought that she intended the silly Marianne of "Sense and Sensibility" for her sparkling self obtained credence because the prudent Elinor was assuredly a loving study of her sister Cassandra. Matters were quite otherwise when George Eliot convinced the literary world that a great star had risen upon the horizon. A forgotten cleric acquired quite a public reputation as the prototype of that Rev. Amos Barton, whose "sad fortune" we have all compassionated. Nay, enthusiasts carried things so far as actually to raise a tablet above the ashes of an obscure sleeper to record the fact that here lay the mortal remains of her who inspired the fadeless picture of that saintly woman, Dinah Morris. What greater tribute can the world pay a novelist than to remember an actual man or woman merely because his or her shadow has crossed the path irradiated by a potent imagination?

Publish

There is futile talk that Dickens is going out of fashion, that he is not read. ers' statistics, however, bear overwhelming testimony to the contrary. The great masses laugh over their "Pickwick" as heartily as did their grandparents when they watched greedily for the green numbers that came with every month. Perhaps these readers trouble themselves less as to whether Dickens drew Micawber from his own shiftless, happy-golucky parent, than readers did when he first stepped upon the stage. Yet a beautifully printed gift-book just issued under the title of "The Country and Church of the Cheeryble Brothers," by the Rev. Hume Elliot, is a sufficient proof that the old curiosity is far from extinct. Until the glorious old twins entered "Nicholas Nickleby," the merchant had usually been a shady person in fiction, overgiven to fraud and embezzlement, and prone to oppression of the orphan. What wonder, then, that two excellent men rejoiced in the distinction of being cited as the models for