streams of intrinsic energy from their own isolated substance, but are perpetually, though in infinitesimal proportions, changing their elemental nature spontaneously, so as to give rise to other atoms which we recognise as other elements?

It

I cannot venture as an expositor into this field. belongs to that wonderful group of men, the modern physicists, who with an almost weird power of visual imagination combine the great instrument of exact statement and mental manipulation called mathematics, and possess an ingenuity and delicacy in appropriate experiment which must fill all who even partially follow their triumphant handling of nature with reverence and admiration. Such men now or recently among us are Kelvin, Clerk Maxwell, Crookes, Rayleigh, and J. J. Thomson.

Becquerel showed early in his study of the rays emitted by radium that some of them could be bent out of their straight path by making them pass between the poles of a powerful electromagnet. In this way have finally been distinguished three classes of rays given off by radium: (1) the alpha rays, which are only slightly bent, and have little penetrative power; (2) the beta rays, easily bent in a direction opposite to that in which the alpha rays bend, and of considerable penetrative power; (3) the gamma rays, which are absolutely unbendable by the strongest magnetic force, and have an extraordinary penetrative power, producing a photographic effect through a foot thickness of solid iron.

The alpha rays are shown to be streams of tiny bodies positively electrified, such as are given off by gas flames and red-hot metals. The particles have about twice the mass of a hydrogen atom, and they fly off with a velocity of 20,000 miles a second; that is, 40,000 times greater than that of a rifle bullet. The heat produced by radium is ascribed to the impact of these particles of the alpha rays. The beta rays are streams of corpuscles similar to those given off by the kathode in a vacuum tube. They are charged with negative electricity and travel at the velocity of 100,000 miles a second. They are far more minute than the alpha particles. Their mass is equal to the onethousandth of a hydrogen atom. They produce the major part of the photographic and phosphorescent effects of the radium rays.

The gamma rays are apparently the same, or nearly the same, thing as the X-rays of Röntgen. They are probably not particles at all, but pulses or waves in the ether set up during the ejection of the corpuscles which constitute the beta rays. They produce the same effects in a much smaller degree as do the beta rays, but are more penetrating,

The kind of conceptions to which these and like discoveries have led the modern physicist in regard to the character of that supposed unbreakable body-the chemical atom-the simple and unaffected friend of our youth-are truly astounding. But I would have you notice that they are not destructive of our previous conceptions, but rather elaborations and developments of the simpler views, introducing the notion of structure and mechanism, agitated and whirling with tremendous force, into what we formerly conceived of as homogeneous or simply built-up particles, the earlier conception being not so much a positive assertion of simplicity as a non-committal expectant formula awaiting the progress of knowledge and the revelations which are now in our hands.

As I have already said, the attempt to show in detail how the marvellous properties of radium and radio-activity in general are thus capable of a pictorial or structural representation is beyond the limits both of my powers and the time allowed me; but the fact that such speculations furnish a scheme into which the observed phenomena can be fitted is what we may take on the authority of the physicists and chemists of our day.

Intimately connected with all the work which has been done in the past twenty-five years in the nature and possible transformations of atoms is the great series of investigations and speculations on astral chemistry and the development of the chemical elements which we owe to the unremitting labour during this period of Sir Norman Lockyer.

Wireless Telegraphy.-Of great importance has been the

whole progress in the theory and practical handling of electrical phenomena of late years. The discovery of the Hertzian waves and their application to wireless telegraphy is a feature of this period, though I may remind some of those who have been impressed by these discoveries that the mere fact of electrical action at a distance is that which hundreds of years ago gave to electricity its name. The power which we have gained of making an instrument oscillate in accordance with a predetermined code of signalling, although detached and a thousand miles distant, does not really lend any new support to the notion that the oldtime beliefs of thought-transference and second sight are more than illusions based on incomplete observation and imperfect reasoning. For the important factors in such human intercourse-namely, a signalling-instrument and a code of signals-have not been discovered, as yet, in the structure of the human body, and have to be consciously devised and manufactured by man in the only examples of thought-transference over long distances at present discovered or laid bare to experiment and observation.

High and Low Temperatures.-The past quarter of a century has witnessed a great development and application of the methods of producing both very low and very high temperatures. Sir James Dewar, by improved apparatus, has produced liquid hydrogen and a fall of temperature probA number of applicaably reaching to the absolute zero.

tions of extremely low temperatures to research in various directions has been rendered possible by the facility with which they may now be produced. Similarly high temperatures have been employed in continuation of the earlier work of Deville, and others by Moissan, the distinguished French chemist.

Progress in Chemistry.-In chemistry generally the theoretical tendency guiding a great deal of work has been the completion and verification of the "periodic law" of Mendeléeff; and, on the other hand, the search by physical agents such as light and electricity for evidence as to the arrangement of atoms in the molecules of the most diverse chemical compounds. The study of valency" and its outcome, stereochemistry, have been the special lines in which chemistry has advanced. As a matter of course hundreds, if not thousands, of new chemical bodies have been produced in the laboratory of greater or less theoretical interest. The discovery of the greatest practical and industrial importance in this connection is the production of indigo by synthetical processes, first by laboratory and then by factory methods, so as to compete successfully with the natural product. Von Baeyer and Heumann are the names associated with this remarkable achievement, which has necessarily dislocated a large industry which derived its raw material from British India. 1

Astronomy. A biologist may well refuse to offer any remarks on his own authority in regard to this earliest and grandest of all the sciences. I will therefore at once say that my friend the Savilian Professor of Astronomy in Oxford has turned my thoughts in the right direction in regard to this subject. There is no doubt that there has been an immense "revival" in astronomy since 1881; it has developed in every direction. The invention of the dry plate," which has made it possible to apply photography freely in all astronomical work, is the chief cause of its great expansion. Photography was applied to astronomical work before 1881, but only with difficulty and haltingly. It was the dry-plate which made long exposures possible, and thus enabled astronomers to obtain regular records of faintly luminous objects such as nebulæ and star-spectra. Roughly speaking, the number of stars

1 I had at first intended to give in this address a more detailed and technical statement of the progress of science than I have found possible when actually engaged in its preparation. The limits of time and space render any such survey on this occasion impos-ible, and, moreover, the patience of even the general meeting of the British Association cannot be considered as unlimited. With a view to the preparation of a more detailed review, I had asked a number of friends and colleagues to send me notes on the progress and tendency in their own par icular branches of science. They responded with the greatest generosity and unselfishness. I must entirely disclaim for them any responsibility for the brief detached statements made in the address. At the same time I should wish to thank them here by name for their most kind and timely help. They are: Sir William Ramsay, Mr. Soddy, Prof. H. H. Turner, Dr. Marr, Dr. Haddon, Dr. Smith Woodward, Prof. Sherrington. Prof. Farmer, Prof. Vines, Dr. D. H. Scott, Prof. Meldola, Dr Macdougal, Prof. Poulton, Mr. C. V. Boys Major MacMahon, and Mr. Mackinder.

text-books on the subject (e.g. Rosenbusch's "Microscopical Physiography") as being cut "so that one of its faces is exactly parallel to the principal axis (optic axis, axis of least elasticity)." The difficulty in getting, say, iron-grey of the first order depends on the extreme thinness of the quartz required at the thin end of the wedge.

Now the interference colour given by plates of equal thickness of the same mineral depends on the direction in which they are cut, varying from a maximum when the plate is parallel to the optic axis to zero when the plate is perpendicular to that direction (assuming the mineral to be uniaxial). If, then, a wedge be made having one face parallel to some such direction as, say, an orz face of the quartz crystal and its length in the direction of the trace of the vertical plane of symmetry through that face, it will give the same results as the ordinary quartz wedge, but, for the same thickness, will give a lower colour, so that the colours at its thin end may be got very low. On trial a wedge made in this way gave very satisfactory results.

The compound wedge described below, which, so far as I know, is also new, was found to be still better. Suppose a sheet of muscovite be taken, its axes of elasticity determined, and a strip cut of the same size and shape as the quartz wedge with the axis of greatest elasticity parallel to its greatest length. If the wedge is covered with the mica plate and examined between crossed Nicols, there will, of course, be a black compensation band in some position, and by cleaving the mica thinner this band can be made to move towards the thin end of the wedge, and finally to coincide with it. The mica is now cemented to the quartz, and a wedge is produced which gives all the colours of the first order. By the use of this compensation mica plate a very poor wedge may be converted into a firstclass instrument, or one broken at its thin end restored to usefulness. DANIEL JAMES MAHONY. The Grand Hotel, Melbourne, Victoria, June 25.

Colour Phenomena in "Boletus cærulescens." ONE day recently in the woods at Lynton (where the soil is red) I found and gathered two very beautiful toadstools, with vermilion stem and bright, sulphur-coloured hymenium. In these individuals the striking colour phenomena peculiar to their family were remarkably in evidence; in the brilliant sunlight on the bright yellow under-surface of the pileus I found my name when traced in the most gentle way shine out almost immediately in the most magnificent of blues.

Will any of your readers kindly refer me to any recent papers concerning the chemical or physical processes which underlie this fascinating demonstration? From my own superficial observations it is evident, I think, that light plays an important part. The energy liberated by the very gentlest friction appears to be a sufficient initiative.

Parts that have been rendered blue, when left at rest, after a short time return to yellowness, but these same parts are capable under fresh stimulus, so long as the fungus is still alive, of again assuming temporary blue

ness.

The juice expressed from blue areas is itself bright blue, and imparts a bright blue stain to linen. Upon my handkerchief this colour remained so long (at least five hours) that I thought I had fixed it; but in the morning the dry blue patch of the night before was no longer blue, but yellow.

On cutting the stem its upper two-thirds was found endowed with the property of cœrulescence; but this was not in any degree possessed by its lower third, in which the cut surfaces remained of a reddish-brown colour. With the exception of the lower part of the stem and the cuticle, all the tissues of the fungus exhibited cœrulescence.

I take special interest in these observations on account of certain phenomena noticeable in human tissues in the course of a somewhat rarely met with pathological condition which has been described under the name chloroma.

Without entering into details, I may remark that along with the colour development which characterises this pathological condition hæmoglobin is probably being extensively

set free from red blood cells, and presumably this body or its derivatives are abnormally abundant in the body fluids. Is there any known organic iron-containing body capable of being responsible for these quick-change effects? EDGAR TREVITHICK.

Strength of a Beetle.

LAST night a small beetle (Aphodius fossor), the length of which is inch, flew in at my window and alighted on a table next to me. As it buzzed about I put a lid of a tin box over it, but to my surprise the beetle walked about bearing the lid on its back. I then put the tin box on the top of the lid, and was absolutely amazed to find that the insect tilted up a corner of the combined box and lid, and nearly escaped. The weight of the beetle when dead was grain, alive I suppose it was a little more: but the box and lid weighed 1758 grains! Assuming that the living insect weighed 1 grain, it must have tilted up 1758 times its own weight! Of course, the strength required to tilt up a box on edge is nothing like so great as that required actually to lift the weight, but nevertheless the feat seems to me sufficiently astounding. dimensions of the box are 3×2×1 inches.

The

CHARLES R. KEYSER.

The Gables, Hayward's Heath, July 26.

OF

THE INTERNATIONAL CELEBRATION
THE JUBILEE OF THE COAL-TAR IN-
DUSTRY.

DURING the last century no discovery, perhaps, has led to such far-reaching and important developments as that of mauve, the first aniline dye, by William Henry Perkin. Not only was the door thrown open to the never-ending procession of artificial colouring matters, but the raw materials necessary for their production were also the raw materials for the synthesis of whole series of entirely different substances, which have now assumed most important positions in the world's daily requirements. It cannot be too often repeated that Perkin's discovery was the result of true scientific devotion to pure research. The synthetic preparation of quinine was the goal aimed at a sufficiently ambitious one for a lad of seventeen, for the problem is yet unsolved. Perkin did not state, as is perhaps too often done nowadays, that " only a black mass was obtained." His persevering and scientific habit of mind led him to investigate the "black mass," with the result that by extraction with alcohol was isolated the violet dye which is so closely associated with his name.

Great though Perkin's discovery was, yet greater still were the zeal, industry, and genius of the boy of eighteen which enabled him to make the dyestuff on the large scale and place it on the market successfully. Only those who have had experience in largescale preparations can realise what this must have meant. New plant, new materials, new conditions: all had to be undertaken, and in the introduction of iron vessels for the manufacture of his raw material, aniline, Perkin laid the vast aniline oil industry under lasting obligation.

The start thus given, many entered the field; by a slight variation of Perkin's process Renard and Franc introduced the splendid crimson dye magenta "in France, whilst shortly afterwards Simpson, Maule, and Nicholson started the manufacture of this colour in London. The happy collabor ation of A. W. Hofmann, the college professor, with the splendid technical chemist and business man, E. C. Nicholson, soon not only placed the London firm in a commanding position, but gave to the world those researches on rosaniline for which Hofmann became so famous.

In the meantime, Perkin not only manufactured mauve, but was steadily working at the artificial products of alizarine, which he was able to obtain in 1868, and immediately produced it on the large scale. In 1873, recognising that a very largely increased manufacturing scale was necessary for the highest degree of success (a principle since so thoroughly carried out by the large German firms), Perkin decided to retire from business, and his works were sold. After some vicissitudes the business was transferred to Silvertown, where the British Alizarine Company carries on a large and successful manufacture of alizarine dyes.

From the beginning the development of the industry steadily continued, both in England and on the Continent. In 1859 Griess, a chemist employed at Allsopp's Brewery, discovered the first azo dye, which was manufactured in 1863 by Simpson, Maule, and Nicholson. This was the starting point of one of the most important branches of the colour industry, and was rapidly followed by many brilliant discoveries by Hofmann, Nicholson, Caro, Martius, and Witt in England, Girard and De Laire and Poirrier in France, and Baeyer, Böttiger, Duisberg, and many others in Germany.

The outcome of this has been that the colour industry has progressed to one of enormous import

ance. The combination of scientific research and business skill so strikingly exampled by Perkin and Nicholson has been applied in Germany with marvellous success, and has resulted in the development of several great firms, each employing several thousands of workmen and hundreds of chemists and engineers.

The example set by Englishmen has not been followed to the same extent in this country, and the industry, affected by the fall of one or two historic houses, has progressed but slowly.

In failing to synthesise what is perhaps the most important aid known to medicine, Perkin gave to medicine its most potent drugs; for the separation of hundreds of products from coal-tar has enabled chemists to prepare phenacetin, antipyrin, antifebrin (the latter actually produced on the large scale as a bve-product by Perkin), and many others. Extensive manufactories of saccharin, photographic developers, and pharmaceutical products have been erected, and, indeed, it is difficult to say where the far-reaching influence of Perkin's discovery may end. One thing is sure. it is not to be measured by mere statistics; in the words of Hofmann, .. is transparent enough. Whenever one of your chemical friends, full of enthusiasm, exhibits and explains to you his newly-discovered compound, you will not cool his noble ardour by asking him that most terrible of all questions, What is its use? Will your compound bleach or dye? Will it shave? May it be used as a substitute for leather? Let him quietly go on with his work. The dye, the leather, will make their appearance in due time. Let him, I repeat, perform his task. Let him indulge in the pursuit of truth,-of truth pure and simple,-of truth not for the sake of Mauve, let him pursue truth for the sake of

the moral of Mauve.

truth! "

...

It was a peculiarly happy circumstance that the meeting to honour Sir William Henry Perkin should have been held in the Royal Institution. The most elementary constituent of coal-tar, viz. benzene, was discovered here by Faraday in 1825, and this was followed by Perkin's own discovery of mauve in his home laboratory. "Let me tell you then," said Hofmann in the lecture room in 1862, "that Mauve and Magenta are essentially Royal Institution colours:

the foundation of this new industry was laid in Albemarle Street."

The whole of the chemical world was represented at the meeting on July 26, which was presided over by Prof. R. Meldola, F.R.S. It is only necessary to mention such names as Emil Fischer, H. Caro, Albin Haller, P. Friedländer, C. Duisberg, G. Schultz, A. Bernthsen, C. Liebermann, R. Möhlau, in order to indicate that the very foremost of foreign chemists were present, and all the representative English men of science and technology were to be seen at this historic gathering. The presentation of the Hofmann and Lavoisier gold medals, the foreign university degrees, and the great number of congratulatory addresses gave ample proof, were it needed, of the admiration with which all chemists regard the founder of this great industry.

At the dinner in the Whitehall Rooms in the even

Mr.

ing (Prof. Meldola in the chair), tributes were paid by an even wider circle of appreciative admirers. Haldane, His Majesty's Secretary of State for War (who proposed the toast of the evening), the Earl of Halsbury, Lord Alverstone, Sir William Broadbent, Sir Henry Roscoe, Profs. E. Fischer and A. Haller, Sir Robert Pullar, and the chairman pointed out the benefits accruing, not merely to the colour industry, the dyeing trade, the medical profession, and science

at large, but also to the whole world.

On the following day Sir William and Lady Perkin entertained a large number of guests at The Chestnuts, Sudbury, near Harrow. The old Greenford works and Sir William's private laboratory were visited, whilst in the beautiful garden one saw the madder plants which came from the late Dr. Schunck's garden in Manchester.

Sir William and Lady Perkin's reception in the Hall of the Leathersellers' Company concluded the festivities, which will never be forgotten by those who were privileged to take part in them.

J. C. CAIN.

THE SPORADIC PUBLICATION OF
SCIENTIFIC PAPERS.

IN these latter days the development of science has led to an inverted fulfilment of the old prophecy, "Men shall run to and fro and knowledge shall be increased." Nowadays men have to run to and fro because knowledge is increased. A very considerable portion of the time of a man of science is taken up in "running to and fro" seeking for the papers which he wishes, which, indeed, he is bound to consult. There are various ways in which much of the time thus spent might be saved, and some of these ways are being more or less successfully made use of. One cause, however, of this "running to and fro " deserves special attention, because it seems really unnecessary, and the time spent through its continuance may be said to be time wholly wasted.

It has been my lot to receive almost at the same time a number of the Journal of the Marine Biological Association, a volume of the Scientific Memoirs of the Officers of the Medical and Sanitary Departments of the Government of India, a volume of the Thompson-Yates and Johnston Laboratories Reports, and the annual Report of the Medical Officer of Health to the Local Government Board.

All these contained papers of great scientific value, and I feel sure that many besides myself are continually having brought before them similar instances of the abundance of what I venture to call the sporadic publication of scientific papers. This has been very strikingly brought home to those who have had to

do with the Royal Society's Catalogue of Scientific Papers or the International Catalogue of Scientific Literature.

Now two channels for the publication of scientific papers must be accepted without cavil.

In each country (for international publications, however desirable, present almost insurmountable mechanical difficulties) it is well that there should be a periodical devoted to each "branch" of science, and as time goes on each "branch" will naturally become more and more subdivided. This may be regarded as the natural, and, putting on one side historical considerations, the first channel.

But the publications of established academies and of the older special societies must be accepted also. The newer special societies would do well to make use of the special journals, in some such way as the Physiological Society makes use of the Journal of Physiology, and perhaps even some of the older ones might adopt the same methods.

In any case, there is no reason for special comment on these two channels. But things are different when we come to consider the kind of publication of which I have given examples above.

Let me take, for instance, the Journal of the Marine Biological Association, and the Thompson-Yates and Johnston Laboratories Reports. The number of the former is almost wholly occupied by a memoir of systematic zoology, the number of the latter by papers on trypanosomiasis. Why should the student in systematic zoology, who has possibly at some expense taken steps to secure ready access to the publications of the Zoological and Linnean Societies, have also to run after the Journal of the Marine Biological Association?

Why should the student in tropical diseases have to run hither and thither, seeking in this and that report what he ought to find ready at hand either in the Journal of Comparative Pathology or Journal of Hygiene, or some still more special periodical?

Now there can be no doubt that the causa causans of the two periodicals in question is advertisement. One cannot but sympathise with the efforts of the Marine Biological Association to make its worth known; one has also sympathy with the University of Liverpool, but less acute since its great merits are in everyone's mouth. But I venture to put the question, Is it desirable that, for the mere sake of advertisement, the progress of science should be hindered? For anything which puts obstacles in the way of the student getting ready access to a knowledge of what has been done is a distinct hindrance to progress. Why should not the Marine Biological Association spend the money which it has spent in printing the Hon. C. Eliot's valuable memoir on British nudibranchs in subsidising some acknowledged channel of zoological publication. It is well that the association should have a journal, but that journal ought to be occupied exclusively by business matters; all scientific papers of permanent value produced by help of the association ought to be published elsewhere.

In the same way, why should not the Liverpool University spend some of the ample funds at its disposal in subsidising periodicals, many at least of which are in urgent need of support? This would in the end be even a better advertisement.

The Lister Institute sets in this respect a very good example. It too has need of advertisement, but the results of the varied work carried on there are

published each in an appropriate acknowledged channel. It limits its direct advertisement to issuing in a collected form reprints of the various papers scattered over many periodicals.

The scientific papers in Government publications stand on a somewhat different footing from those just spoken of. The Annual Report of the medical officer of the Local Government Board referred to above contains, besides several papers of direct administrative value, under the term "report" a number of valuable papers of a purely scientific character, papers to which every inquirer in pathology ought to have ready access. But why should a scientific library, and why especially should the limited library of a pathological institute or laboratory, for the sake of a mouthful of pure science, burden its shelves with an intolerable mass of adminis trative details? The publications of the medical officer of the Local Government Board do not stand alone in this respect. In the enormous mass of printed matter which H.M. Government puts out every year there are hidden, buried, lost to view, records of scientific research of varying but not unfrequently of great value, records to which the scientific inquirer ought to have ready access. This official burial of scientific work does a double harm; it harms him who did the work, it harms all those who, through the burial, miss knowing what has been done.

Of course it must be recognised that H.M. Government, having ordered and supplied the funds for a scientific inquiry, has a right of possession in the records of that inquiry, so that by the official publication of that record it may justify before Parliament and the public the order for the inquiry. The matter is further complicated by the fact that when the order for inquiry is part of the work of a Royal Commission, the results of such an inquiry cannot be made known until the report of the commission on its work as a whole is laid before Parliament and published.

But these difficulties are not such as cannot be overcome. A small Commission of the nature of what is known as a Departmental Committee, appointed some little time back to investigate plague in India, has, with the approval of the authorities, adopted the following plan. While making the usual arrange ments for the reports on administrative matters, it proposes to publish from time to time the scientific results of the work of the commission in an appropriate scientific journal, securing, by the purchase of extra copies of the records thus published, the means for the complete publication of the whole work of the commission at some future period.

Such a plan might be extended to all scientific inquiries carried out by order of H.M. Government; it needs nothing more than frank negotiations between persons responsible to H.M. Government and editors of scientific periodicals. Such a plan would bring many blessings. It would enable the man of science who is putting his best into the work which he is doing for Government to feel that the record of his work will not be hopelessly lost sight of. It would save other men of science the labour of hunting for scientific needles in Government bottles of hay, or the chagrin of finding out, when too late. that by shrinking from such uncongenial labour they had missed something of great price. It would save the nation a not inconsiderable sum of money, and yet furnish the editors of scientific journals with money, which many of them need for the conduct of their journals, and which most of them at least would use in helping the poor author to a more complete publication of the records of his work. Lastly it would relieve the bibliographer from much weari some labour. In every way, in fact, it would tend to advance natural knowledge.

X