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idable computations required by the large mass of observations made by the department at San Luis, Argentina, researches are simultaneously continued on the problems of star-drift, including the speed and direction of motion of our solar system. In the meantime, the catalogue is progressing favourably and some portions of the observatory list of miscellaneous stars are approaching completion, although cloudiness during the past two winters has interfered with this part of the departmental programme. In the meantime, also, the manuscript of the zone catalogue of stars the positions of which were measured at the observatory during the years 1896 to 1900, is undergoing the final process of comparison and checking preparatory to publication.

The anticipations of a specially favourable environment, which were entertained when the Nutrition Laboratory was located in Boston near the Harvard Medical School and near several existing and projected hospitals, are now fully realised; and it would appear that the laboratory is reciprocally advantageous to the several establishments with which it is in immediate contact. Indeed, with this, as with all other departments of research founded by the institution, the only fears to be entertained seriously are those due to increasing capacity for usefulness and scientific progress, since such capacity tends quite properly to grow faster than the institution's income

warrants.

Improvements have been made in the laboratory itself, and several additions to equipment have been installed. These latter include new respiration apparatus for studies of metabolism in muscular work of men and of small animals, a reconstruction of an earlier form of bed calorimeter, and additional apparatus for photo-electric registration of physiological action in subjects under observation, whether near by or at a distance.

As indicated in previous reports, the laboratory and its work are subjects of international as well as national interest, and many co-operative efforts are arising therefrom. Among the researches in progress by the laboratory staff, attention may be directed particularly to "The gaseous metabolism of infants with special reference to its relation to pulse-rate and muscular activity," by Francis G. Benedict and Fritz B. Talbot, and to "A study of prolonged fasting," by Francis G. Benedict.

The extensive operations of the Department of Terrestrial Magnetism on the oceans and in foreign countries have been adequately supplemented during the year by the new departmental laboratory, the completion and occupation of which took place nearly simultaneously with the beginning of the second decade of the department's existence. This laboratory and its site provide greatly enlarged facilities for research, as well as unsurpassed quarters for the resident departmental staff.

Near the end of the preceding year the non-magnetic ship Carnegie returned to New York City, where she underwent such extensive repairs as are always required by wooden vessels after long cruises in tropical waters. After refitting, she left New York, June 8, 1914, for a cruise in the North Atlantic. In this, the third of her expeditions, she traversed about 10,660 miles, making a first stop at Hammerfest, Norway, July 3, reaching the high latitude 79° 52' off the north-west coast of Spitsbergen, touching at Reykjavik, Iceland, August 24, and returning to the base station at Greenport, Long Island, October 9, and to Brooklyn, New York, October 21. During this cruise the Carnegic was in command of Mr. J. P. Ault. She is now being refitted for a longer cruise during 1915-16, in southern latitudes (50° to 75°), where magnetic observations require supplementing.

An attempt at an ocean expedition into Hudson Bay was made under the charge of Mr. W. J. Peters during the past summer, but on account of unusual obstacles from ice this proved only partly successful. Entrance into the Bay with the auxiliary schooner George B. Cluett, chartered for this purpose from the Grenfell Association, was blocked until September 2, leaving less than a month's time available for surveys. Determinations of magnetic elements on land have been continued in six parts of Africa, in as many States of South America, and in Australia, bringing the surveys of all these continental areas to a welladvanced stage.

With the end of the current year the Mount Wilson Solar Observatory, like most other departments of the institution, will have completed a first decade of its history. Quite appropriately, this establishment was founded at an epoch of maximum sun-spots, and a marked increase in solar activity during the past year furnishes similarly auspicious conditions for entrance into a second decade of research. But much more auspicious conditions are found in the extensive experience and in the effective equipment acquired along with the capital progress attained during this first decade. The most sanguine astronomer would have hesitated at the earlier epoch to predict that these latter conditions could be realised at the present epoch. Herein also is found a signal illustration of the superior effectiveness of establishments primarily designed for and exclusively devoted to research as compared with establishments in which research is a matter of secondary interest.

Progress in construction of the 100-inch telescope has been made as rapidly as could be expected in so formidable an undertaking. The delicate optical task of shaping the 100-inch mirror has been brought successfully by Mr. Ritchey to the stage of sphericity which precedes the final state of parabolisation. The difficulties due to distortion of the mass of the disc, referred to in previous reports, have been overcome, and other obstacles due to temperature inequalities in the optical room are likewise yielding to appropriate precautions. In the meantime, the foundations for this telescope have been completed, and the mounting and dome are expected to be ready for erection during the coming year. Several smaller parts and accessories for this instrument, requiring special exactness, are under construction at the shops of the observatory in Pasadena. Many additions and improvements in the apparatus already installed at the observatory have been made. The 60-foot tower telescope particularly, which was originally cheaply constructed in order to test the possible advantages of such a departure from earlier forms of telescopes, has been put in a state of efficiency comparable with that of the 150-foot tower telescope, leaving the latter free for the uses to which it is specially devoted. In these general improvements much attention has been given to rendering the plant on Mount Wilson more nearly fireproof. The mountain road has been repaired, widened, and strengthened in many parts in anticipation of the heavy traffic essential to transportation of the 100-inch telescope to its destination.

UNIVERSITY AND EDUCATIONAL

INTELLIGENCE.

CAMBRIDGE.-The Adams prize for 1913-14 has been awarded to Mr. G. I. Taylor, Smith's Prizeman in 1910. The subject selected was "The phenomena of the disturbed motion of fluids, including the resistances encountered by bodies moving through them." The value of the prize is about 250l.

IT is stated in Science that by the will of General Brayton Ives, of New York City, the largest part of his estate is bequeathed to Yale University for its general purposes. The value of the bequest is estimated at from 150,000l. to 300,000l.

WE learn from Science that through the efforts of Dr. Ralph Arnold, and other alumni of the department of geology and mining, Stanford University has just added to its collections the working library and material of the late Prof. H. Hemphill, of Los Angeles. The collection contains between 8000 and 9000 specimens of shells and 150 volumes. The material is of great importance in the study of the Tertiary geology of the Pacific coast, and especially of the geology of the petroleum deposits of California.

THE March number of the Nature-Study Review (Ithaca, N.Y.), the official organ of the American Nature-Study Society, is devoted to an elaborate prospectus of courses in nature-study for elementary schools. It has been prepared by Mr. G. H. Travers and Miss H. M. Reynolds, of the Minnesota State Normal School, and it is copyright. The authors take a big view of their subject, and emphasise "the æsthetic, the social, the economic, and the hygienic" aims of nature-study. (The old-fashioned teacher will rather miss the intellectual aim!) To help the pupils to enjoy the world they live in, and to acquaint them with the useful and injurious forms of life, these we understand as the æsthetic and economic aims, but the social aim, so far as explained, seems to us far-fetched, and the hygienic aim is lugged in by sheer force. The "disciplinary theory" of training the powers of observation, memory, reasoning, and imagination must be given up, we are told, for the researches of modern psychology have shown it to be unsound. But it seems to reappear under another name. To more purpose, as it seems to us, the authors emphasise that the nature-study should deal with the material available in the child's environment, which in urban conditions requires to be enlarged artificially. The starting point should always be in the child's experience, and the material should be of interest or capable of becoming of interest to the child. Each study should concern itself with a child's problem, and the child should be guided to solve it. And the solution should mean something in the life of the child. "If the problem does not seem to allow of any application, we may well inquire whether the problem is really worth while." This may be pushed too far, for a stimulated imagination may be a great gain and a search for applications a bore. The graded outlines of courses are carefully thought out, and the general arrangement-following the seasons-is admirable. Teachers will find the outlines very suggestive and the introductory essay very provocative. We would particularly commend the consistent way in which the authors have sought to get at the child's point of view, and to keep to the Socratic method, not in the letter alone, but also in the spirit.

SOCIETIES AND ACADEMIES.
LONDON.

Royal Society, March 25.-Sir William Crookes, president, in the chair.-Prof. B. Moore: The production of growths or deposits in meta-stable inorganic hydrosols.-Prof. B. Moore and W. G. Evans: Forms. of growth resembling living organisms and their products slowly deposited from meta-stable solutions of inorganic colloids.-H. Onslow: A contribution to our knowledge of the chemistry of coat-colour in animals and of dominant and recessive whiteness. This research was undertaken in order to discover a chemical method

Dark

of differentiating the two similar forms of white animals known as dominant whites and recessive whites, or albinos. Hitherto this has only been possible by observing their genetic behaviour. animal pigments are believed to result from the oxidątion of a colourless chromogen by an oxydase. The skins of young black rabbits were found to yield a tyrosinase which converted tyrosine to a melanin. By means of this tyrosinase it was possible to test extracts from white rabbits of both types. Briefly, extracts from dominant whites contained an antioxydase which inhibited the tyrosinase of the black rabbit extracts. Extracts from albinos, on the other hand, had no inhibiting influence, and were themselves incapable of producing any pigment. The antioxydase was also found in those white parts of rabbits which are dominant to colour, such as the white bellies of the wild rabbit and of the yellow rabbit carrying agouti. These results tend to confirm the Mendelian view that dominant whiteness is caused by a factor which inhibits the pigment-producing mechanism if present, and that albinism results from the partial or total absence of the factors necessary for the development of pigment. The experiments also revealed facts which suggest that the difference between pigments producing black, chocolate, and yellow hairs is quantitative rather than qualitative, for, after extraction, the pigments in all three colours appear identical. That variation in colour is a structural modification is supported by the fact that dilute colours, such as blue, are caused by a lack of pigment in the cortex. In the corresponding intense colours, such as black, pigment being present in the cortex, the white light reflected from the vacuoles is absorbed, thus deepening the colour.

PARIS.

Academy of Sciences, April 12.-M. Ed. Perrier in the chair.-E. Guyou: Remarks on the Extrait de la Connaissance des Temps for 1916. An account of the modifications introduced with the view of shortening and facilitating nautical calculations.-A. Müntz and E. Lainé: Study of the material brought_down by watercourses in the Alps and Pyrenees. Determinations of the quantities of material carried by the principal watercourses in the Alps and Pyrenees. The erosion is much more intense in certain recent formations. The agricultural value of the deposits has still to be examined.-M. de Forcrand : A hydrate of hydrogen arsenide. The hydrate AsH,,6H2O has

been isolated and determinations made of its dissociation_pressures at temperatures from o° C. to 25° C. From these data, with the aid of Clapeyron's equation, the heat of formation has been found to be 17.75 calories. Comparisons are given for analogous data for the hydrogen compounds of sulphur, phosphorus, and selenium.-J. Guillaume: Observations of the sun made at the Observatory of Lyons during the third quarter of 1914. Observations were made of sixty-seven days, and the results are given in three tables showing the number of spots, the distribution of the spots in latitude, and the distribution of the faculæ in latitude.-S. Chevalier: The effect of atmospheric dispersion on the diameter of photographed celestial objects. Photographs of the sun and of Jupiter show that the effect of atmospheric dispersion on the diameter of a photographed celestial body depends very slightly on the brightness of the body or on the sensibility of the plates.-Ernest Esclangon: The limited integrals of a linear differential equation.-Ph. Flajolet Perturbations of the magnetic declination at Lyons (St. Genis Laval) during the third quarter of 1914.-M. Lubimenko: Some experiments on the antioxydase of tomato fruits. Details are given of a

method for estimating the amount of peroxydase in the tomato, and this method was applied to determining the proportions of peroxydase during the different stages of the ripening of the fruit. From the results obtained, it is conIcluded that the tissue of the tomato contains an enzyme which paralyses the oxidising action of the peroxydase. This is provisionally termed antiperoxydase, and it is much more sensitive than the peroxydase to the influence of antiseptics. Even toluene destroys it fairly rapidly. The relations between these two enzymes during the ripening of the fruit is discussed.-A. Jungelson: Chemical intoxication and mutation of maize. Studies in the variations produced by treating the seed with a solution of copper sulphate.-H. Vincent and M. Gaillard: The purification of drinking water with calcium hypochlorite. Compressed tabloids of 0.015 gram calcium hypochlorite with 0.08 gram salt are used. These contain 3.5 mgr. of active chlorine, and one is capable of sterilising a litre of water in about twenty minutes. There is no appreciable taste. Bacteriological experiments are given showing the removal of pathogenic bacteria.-J. Vallot: An installation permitting the application of intensive heliotherapy, in winter, to wounded and military convalescents.-MM. Hirtz and Gallot: A new radioscopic method for the determination of the depth of a foreign body in the organism.

BOOKS RECEIVED.

Year Book of the Royal Society of London. Pp. 250. (London: Harrison and Sons.) 5s.

Imperial University of Tokyo. Calendar 2573-2574. (Tokyo: Z. P. Maruya and Co.)

Royal Societies Club. Founded A.D. 1894. Foundation and Objects. Rules and By-Laws. List of Members. Pp. 354. (London.)

Practical Irrigation and Pumping. By B. P. Fleming. Pp. xvi +226. (New York: J. Wiley and Sons, Inc.; London: Chapman and Hall, Ltd.) 8s. 6d.

net.

The Design of Steam Boilers and Pressure Vessels. By Prof. G. B. Haven and G. W. Swett. Pp. vii+ 416. (New York: J. Wiley and Sons, Inc.; London: Chapman and Hall, Ltd.) 12s. 6d. net.

Electrical Engineering. By Dr. T. C. Baillie. Vol. i., Introductory. Pp. vii+236. (Cambridge: At the University Press.) 5s. net.

DIARY OF SOCIETIES.

THURSDAY, APRIL 22.

ROYAL SOCIETY, at 4.30.-Deep Water Waves, Progressive or Stationary,
to the Third Order of Approximation: Lord Rayleigh.-A Chemically
Active Modification of Nitrogen, produced by the Electric Discharge.
VI. Hon. R. J. Strutt.-The Difference between the Magnetic Diurnal
Variations on Ordinary and Quiet Days at Kew Observatory: Dr. C.
Chree. The Effects of Different Gases on the Electron Emission from
Glowing Solids: F. Horton.-Heats of Dilution of Concentrated Solutions:
W. S. Tucker. -The Origin of the "4686" Series: T. R. Merton.
ROYAL INSTITUTION, at 3.- The System of the Stars: The Stellar System
in Motion Prof. A. S. Eddington.

FRIDAY, APRIL 23.

ROYAL INSTITUTION, at 9.-Military Hygiene and the War: Major P. S.
Lelean.

INSTITUTION OF MECHANICAL ENGINEERS, at 8.
PHYSICAL SOCIETY, at 5.-The Theories of Voigt and Everett Regarding
the Origin of Combination Tones: Prof. W. B. Morton and Miss Mary
Darragh. -Experiments on Condensation Nuclei Produced in Gases by
Ultra-Violet Light: Miss Maud Saltmarsh.-The Self-Induction of
Solenoids of Appreciable Winding Depth: S. Butterworth.

SATURDAY, APRIL 24.

ROYAL INSTITUTION, at 3.-Modern Artillery: Lieut.-Col. A. G. Hadcock.

MONDAY, APRIL 26.

ROYAL GEOGRAPHICAL SOCIETY, at 8.30.-Geography of the War Theatre in the Near East: D. G. Hogarth.

ROYAL SOCIETY OF ARTS, at 8.-Foodstuffs: Dr. D. Sommerville. INSTITUTE OF ACTUARIES, at 5.-The New National Life Tables: G. King.

TUESDAY, APRIL 27.

ROYAL INSTITUTION, at 3.-The War on Belgian Architecture: Banister
Fletcher.
ZOOLOGICAL SOCIETY, at 5.30.-White Collar Mendelising in Hybrid
Pheasants: Mrs. Rose Haig Thomas.-Two New Tree-Frogs from
Sierra Leone, recently Living in the Society's Gardens: E. G. Boulenger,
-The Foraminifera of the Kerimba Archipelago (Portuguese East Africa).
Part II. E. Heron-Allen and A. Earland.

ILLUMINATING ENGINEERING SOCIETY at 8.-Visibility: its Practical
Aspects: C. C. Paterson and B. P. Dudding.

INSTITUTION OF CIVIL ENGINEERS, at 8.-Annual General Meeting.

WEDNESDAY, APRII. 28.

ROYAL SOCIETY OF ARTS, at 8.-The Utilisation of Solar Energy: A. S. E. Ackermann.

INSTITUTION OF ELECTRICAL ENGINEERS, at 7.45 (Students' Section).Annual General Meeting.

GEOLOGICAL SOCIETY, at 8.-A Composite Gneiss near Barna (County of Galway): Prof. Grenville A. J. Cole.-Further Work on the Igneous Rocks associated with the Carboniferous Limestone of the Bristol District: Prof. S. H. Reynolds.

THURSDAY. APRIL 29.

ROYAL SOCIETY, at 4.30.-Probable Papers: The Transmission of Inftared Rays by the Media of the Eye, the Transmission of Radiant Energy by Crookes's and other Glasses, and the Radiation from various Light Sources: H. Hartridge and A. V. Hill.-Surface Tension and Ferment Action E. Beard and W. Cramer.-Surface Tension as a Factor controlling all Metabolism: W. Cramer.

ROYAL INSTITUTION, at 3.-Advances in General Physics: Prof. A. W.
Porter.
INSTITUTION OF ELECTRICAL ENGINEERS, at 8.-The Bombay Hydro-
Electric Scheme: A. Dickinson.

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2.

THURSDAY, APRIL 29, 1915.

THE VALUE OF THE RARER
ELEMENTS.

The Rare Earths: their Occurrence, Chemistry,
and Technology. By S. I. Levy. Pp. xiv +
345. (London: Edward Arnold, 1915.) Price
IOS. 6d. net.

THER
Telements in both theoretical and technical

HE rapidly-growing importance of the rarer

directions makes the above volume a welcome addition to English chemical literature. Except for Browning's "Rarer Elements," there is little of importance to turn to for information since the well-known "Terres rares of P. Truchot, published in 1898. The valuable researches of Urbain have removed much of the obscurity that at one time surrounded many members of the yttria group, and has demonstrated the complexity of several that had been thought to be elementary, and quite recently an exhaustive study of the very rare earth scandia by Sir William Crookes has directed attention to this somewhat neglected branch of science.

The title of the present work is rather misleading, for the author deals not only with the rare earths proper, bodies that have always been a perplexity to both the chemist and the theorist, to the former on account of the extreme difficulty that attends their separation and isolation (they have a provoking habit of often turning out to be complex even after their isolation) and to the latter on account of the hopelessness of finding a rational place for them in any of the periodic classifications that have appeared since the original work of Newlands and Mendeléeff. The author also discusses the elements zirconium, thorium, uranium, titanium, the incandescent mantle industry, and the manufacture of artificial silk! These latter are of great interest and importance, but one would scarcely expect to find them in a book under the title of "The Rare Earths."

The book opens with an interesting and suggestive introduction by Sir William Crookes, whose work on rare earths is well known, his numerous researches in this field extending over the last thirty-five years. His remarks refer chiefly to the closely allied elements of the cerium and yttrium groups, and with his characteristic forethought he states his conviction that by following the study of these bodies to their utmost limits "we may arrive at the explanation of wh the chemical elements really are, and how originated, and discover the reasons for th perties and mutual reactions."

The work is divided into three

NO. 2374, VOL. 95]

225

occurrence of the rare earths; the chemistry of the elements; and the technology of the elements. Each section is treated in detail, and contains a large amount of information, showing that the author has a thoroughly practical knowledge of his subject.

To have at hand in one volume such a store of mineralogical, chemical, and technical detail is in itself a great boon, and the work is likely to become a standard of reference.

minerals a somewhat novel classification is adopted In the chapter which deals with the rare "for the sake of convenience," and an alphabetical list is given of those minerals which contain zirconium, thorium, scandium, etc.; the list is said the yttrium and cerium groups as well as titanium, to include all but a few unimportant members of heavy type, are fully discussed in a later section. this class; of these the larger number, printed in No mention is made of carnotite, the hydrated vanadate of uranium and potassium that has radium, nor of the brown wükite that occurs with recently come into prominence as a source of the black variety in Finland. composition, specific gravity, hardness, etc., of ever, the list is a valuable one; it gives the name, As a whole, howfound by lengthy search in recent mineralogical some 150 minerals that could otherwise only be

literature.

The next section, occupying some sixty pages, discusses the minerals in detail, and contains an Ceylon, containing 55-79 per cent. thoria and account of the interesting mineral thorianite, from a considerable amount of helium from which radio-thorium has been prepared by Hahn; also the recently-discovered mineral thortveitite containing 37 per cent. of scandia.

minerals on account of their bearing upon the
Prominence is given to the thorium and cerium
mantle industry; in this connection the chapters.
although carrying as little as 2 per cent. of mon-
on the monazite sands is of great practical value,
azite, the Brazilian deposits are of enormous
thoria that is needed for the mantle industry.
extent and have become the chief source of the
Besides the Brazi
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however,

owered

fate, and the German syndicate, together with the Austrian Welsbach Company, now practically meet the world's demand. What effect recent events will have upon this state of affairs remains to be seen, but it looks as if great opportunities are opening out for English and American technologists if they will but take them.

In a short chapter devoted to the radio-active minerals, reference is made to the recent estimation of the atomic weight of the lead contained in them; if this element is the end-product of the thorium disintegration, the isotope of Soddy, its atomic weight should be slightly higher than that of ordinary lead; the value found in a recent determination is 2084, a result surprisingly in accord with theory.

Part ii. deals with the chemistry of the elements, and this section, occupying some 130 pages, is perhaps the most valuable part of the book. It commences with a discussion of the properties of the elements of the yttrium and cerium groups, and of the methods for their separation; the greatest success appears to follow the method of fractional crystallisation, first successfully applied to didymium by Welsbach in 1885, when he succeeded in separating that supposed element into two bodies, having slightly differing atomic weights, naming them neo- and praseo-dymium; it will be remembered by some that the values published at the time by Welsbach were inverted, praseodymium being given at 143'6 and neodymium as 140'8, and it was not until 1898 that Brauner discovered and directed attention to the mistake.

The discussion of the spectrum examination is a little disappointing; the use of the spectroscope in the analysis of the rare earths is of immense importance; the absorption spectra can now be photographed from the extreme ultra-violet down to the least refrangible limit of the visible spectrum if a suitable source of light is combined with the panchromatic plates that are now on the

market.

In dealing with emission spectra it is suggested that to observe spark spectra one pole of an induction coil is embedded in the oxide to be examined and a spark passed! This seems to be a very unusual procedure; in general practice the spark is either passed between platinum wires in a strong solution of the earth or else carbon rods saturated with the solution are used as electrodes; reference is made to the "reversion spectrum 99 discovered by the late Lecoq de Boisbaudran, but no details are given; as in some cases this method is of considerable value, it may be worth while to note that it is described in the Comptes rendus for 1886 (vol. cii., p. 153).

We must take exception to the rather summary dismissal of the kathode luminescence spectra discovered by Sir William Crookes some years ago; it is stated that the researches of De Boisbaudran, Baur and Mare, and Urbain have shown that these spectra were due to minute traces of a coloured earth in a large quantity of a colourless one, and that the sensitiveness of the method is so great that it cannot be employed for the ordinary purpose of chemical analysis; this may be partly true, but there is abundant evidence of the value of the kathode spectra when applied to the rare earths if the technique of the application is thoroughly understood. The sulphates of many of the earths give discontinuous spectra of great beauty and minute detail quite distinct from the nebulous luminosities produced by mixing coloured and uncoloured earths and submitting the mixture to the action of kathode rays; the oxides also, when in a state of purity and under certain conditions, give rise to a further novel series of characteristic phosphorescence spectra, and it is a matter of regret that this method of analysis has not received the attention that it deserves. We feel that the possibilities connected with it are too valuable to allow it to be lightly set aside as worthless.

For the general examination of the rare earths arc spectra are stated to be the most trustworthy, and a valuable feature is the inclusion of lists of the dominant lines in the spectrum of most of the elements.

The last section, the technology of the elements, is largely occupied with an account of the "mantle" industry; from a very interesting historical sketch it appears that the employment of the rare earths had been suggested for the production of light from very early times; mantles of platinum coated with lime and rare earths were used so far back as 1839, and mantles made from gauze that had been impregnated with lime and nagnesia were used in 1849. The success tha has followed the invention of Auer von Welsbach is due in great measure to the accidental discovery that the combination of about per cent. ceria with thoria greatly increases the luminosity of the material, and this composition is now universal.

The commercial preparation of thorium from monazite is fully set out, and the various fibres used for forming the skeleton of oxide are described. Cotton has been replaced by ramie thread, and this in turn is giving way to artificial silk and similar materials, which on account of their uniformity are found to produce more robust and lasting skeletons.

In addition to the mantle industry there are already many other valuable technical applications

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