Mar., 1904.] 



KXOWI.KDGF. .'V SCIENTIFIC NEWS. 



45 



the emission ceases at the end of some minutes. A block of 

 aluminium struck with a hammer does the same, but the 

 duration of emission is much shorter. In these two cases 

 the molecular constraint is temporary, and the emission of 

 N-rays also. Torsion produces analogous results to com- 

 pression. 



Professor .V. Charpentier's investigations of N-rays are 

 second in importance only to those of their discoverer. He 

 sought for the radiation of N-rays chiefly with the aid of phos- 

 phorescent screens of sulphuret of calcinm. but found that 

 screens coated with platinocyanide of barium, whose fluores- 

 cent intensity he rejjulated. with the aid of a salt of radium, 

 covered with black paper, would give more satisfactory results. 

 By these two processes of research, he discovered that N-rays 

 can have several other origins than those of the sources of 

 light indicated by M. Blondlot. He recognised that the little 

 phosphorescent or fluorescent object increased in luminous 

 mtensity, when it was brought near the body. Moreover this 

 augmentation is more considerable in the neighbourhood of a 

 muscle, and so much the greater as the muscle is strongly 

 contracted. The same thing occurs in the neighbourhood ot 

 a nerve, or of a nervous centre, where the effect increases witli 

 the degree of activity of the nerve or of the nerve centre. By 

 this means, in spite of the delicacy of the observation, one can 

 recognise the presence of a superficial nerve, and follow it. 

 These effects are not only observed by contact with the skin. 

 they are perceptible at a distance. They are transmitted 

 through substances transparent to N-rays (aluminium, paper, 

 glass, &c.), and stopped by the interposition of substances. 

 which are opaque to the same rays, lead (incompletely) or wet 

 paper. They are not due to an increase of temperature in 

 the neighbourhood of the skin, for they continue if several 

 sheets of aluminium are interposed, or of cardbo.ard separated 

 by layers of air and forming a calorific screen. These rays 

 are reflected and refracted like N-rays. 



M. Charpentier has produced foci, manifested by the maxima 

 of brightening by the aid of convergent glass lenses. The 

 position of these foci, or maxima, although difficult to 

 exactly determine, permitted recognition of the fact that the 

 indication of refraction of rays emitted by the body was at 

 least of the class and size of that determined by M. Blondlot for 

 N-rays. It might be asked if the human body really emitted 

 these rays, or if it only stored them up during the day or in 

 the Ught, in the same way as the insulated bodies studied by M. 

 Blondlot. After a sojourn of nine hours in complete darkness 

 the phenomena were the same, and were still more easy of 

 observation, because of the more perfect adaptation of the 

 eye. The nerves and nervous centres, when they are the seat of 

 an excitation, emit the rays in greater abundance. Charpentier 

 has been able to determine the area of the heart ; he has also 

 been able to follow the trajectory of a superficial nerve ; he 

 has been able to recognise the topography by certain psycho- 

 motor zones in the cerebral surface. He has seen in fact, that 

 if the subject of the experiment happens to speak, the de- 

 tective screen, when advanced at the same moment towards 

 the region of the cranium which corresponds to the zone of 

 articulate language, at the level of the left frontal convolutions, 

 is more brightly illumined than when he kept silence. The 

 researches of Charpentier suggest that the radiations called 

 N-rays are not all alike, but must in reahty result from an 

 assemblage of radiations of attributes as diverse as their origin 

 some being emitted especially by the elements of the nervous 

 tissues, and others by those of the muscular tissues. This 

 theory is in accord with the physical observations of M. Bond- 

 lot. Experiments already dating from several months have in 

 fact shown to this eminent physician that the bundles of N- 

 rays broken up by a prism spread themselves into a sort of 

 spectnim, which establishes beyond proof that all the broken 

 rays — rays whose wave length, incomparably smaller than 

 that of light rays — are unequally refrangible, and conse- 

 quently possess each individual attributes. The wave length 

 has been recently determined as not greater than S micro- 

 millimetres — about the one millionth of a centimetre. 



We have received from Mr. H. J. (ilaisher a copy of his 

 March catalogue of ■■ remainders," which we notice contains 

 many valuable and useful volumes in zoology, botany, and 

 the various other branches of natural and applied science. 



The Super-Solid. 



Hints towards a Conception of the 

 4th Dirrvervsion. 



I!y C. E. Bi;nham. 

 Sp.i^cE, as we conceive it, comprises length, breadtli, and 

 thickness, and it is hardly possible to imagine a fourth 

 direction which is none of these. Further than that, our 

 minds are so constituted that we seem to see that such a 

 n w direction could not be. When we have traversed 

 any material substance longitudinally, and across, and up 

 and dov.n we appear to ha\e traversed it exhaus- 

 tively. There is no direction which is not one of these - 

 or, as we might say, there could be no direction which is 

 not one of these three or intermediate between them. 

 This is so as to all material substance, and that it is so 

 as to space in the abstract we feel equally convinced, 

 because by space we mean nothing else but the length, 

 breadth, and thickness which matter occupies or might 

 occupy. 



Yet, as everv appreciative reader of Abbott's Flatland 

 knows, there is more to be said on this matter. Suppose 

 a race of beings whose senses were such that they had 

 never had any reason to suspect thickness as a property 

 of matter, but were only conscious of length and lireadth, 

 would it not appear to them that length and breadth 

 filled all space, and that a third dimension was as im- 

 possible as It was mconceivable ? 



Such a race of beings, conscious only of two dimen- 

 sions, is indeed not unimaginable. Some have even 

 theorised that a sightless snail, crawling from surface to 

 surface, has no concept of any third dimension, but 

 exception might be taken to the blind snail as an e.xample 

 of a Flatlander, for possibly his body might occasionally 

 lap the two sides of a flat stone as he curled over the 

 edge of it. But one can imagine a blind snail-like being 

 of such minuteness that the smallest particles of all other 

 matter were much larger than its body. Such a crea- 

 ture, though three-dimensional itself, might well have no 

 suspicion of any dimension beyond infinite surface. It 

 matters not in the least whether no such snail exists. 

 The fact remains that such existence is imaginable, and 

 that it is evident that in such a state of existence sceptic- 

 ism as to the possibility of a third dimension of matter 

 would be just as deep and instinctive as ours is against 

 the possibility of a fourth. 



We may conclude, then, that our limiting of the num- 

 ber of dimensions possible to space to three, is due to the 

 circumstance that as we are constituted our senses cannot 

 conceive a fourth. To say that, therefore, a fourth does 

 not or cannot exist is to go further than we have warrant 

 for. But though we cannot see or by any sense perceive 

 a fourth dimension in addition to length, breadth, and 

 thickness, we may be able reasonably to infer something 

 about the character of such a hypothetical dimension, 

 assuming, for the sake of discussion, that it may exist. 



Some of the properties of a fourth-dimensional " super- 

 solid" have been dealt with by more than one writer, 

 notably by Spottiswoode, in his Presidential Address to 

 the British .\ssociation at Dublin in 1878, and by 

 Howard Hinton, in his interesting little volume on the 

 subject of the Fourth Dimension. 

 I A suggestion is often met with that Time is the fourth 

 ! dimension of matter. Time may indeed be looked upon 

 as a svmbol of the fourth dimension -an illustration of 

 the possibility of a direction which is neither up nor 

 down, nor from side to side, for in time are there not for- 



