THE CHEMICAL NEWS,

VOL. CXXVII. No. 3302.

BRIDGING THE GAP IN THE SPECTRUM.*

Hertz's classical experiments with electric waves in 1888 not only paved the way for the development of wireless communication, but showed that these waves, as indicated by Maxwell's electromagnetic theory of light, were waves of the same kind as light, for they could be bent by prisms and shown to be a part of a spectrum. The electric waves which Hertz produced in his laboratory were 60 cms. long.

It was not until 1895 that Lebedew obtained electric waves which had a length of 6 mms. Lampa, about the same time, had produced waves of 4 mms. in length. Möbius, in 1918, confirmed the general results of the two foregoing investigators, but he came to the conclusion that their waves were respectively 10 and 7 mms. long. Möbius, from experimental considerations, deduced evidence that in this case anything shorter than the above were ripples as distinct from regular waves.

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At this time, following Langley's searches on the solar spectrum, Rubens and Paschen investigated the infra-red end of the spectrum and detected waves 9.4μ. which is 16 times longer than the wavelength of yellow light.

In 1897 Rubens and Nichols, by means of a multiple-reflection method, succeeded in extending the boundaries of the infra-red spectrum ten-fold. Then the former investigator obtained a further extension by employing Wood's method of focal isolation. Following on this, Rubens and von Bayer, in 1911, measured infra-red waves up to 0.320 mm. in length.

There remained a gap between the heat waves and those produced by electrical apparatus, but this gap Nichols and Tear have now bridged by electrical waves, using a method which is briefly described in the Proceedings of the National Academy of Sciences of U.S.A., Vol. IX., No. 6, June,

* Compiled from Nichols and Tear's paper in the "Proceedings of the National Academy of Sciences of U.S.A.," Vol. IX., No. 6, June, 1923.

Rev., 1896-7, Vol. IV., p. 297), which received the waves. The usual blackened vanes in this radiometer were replaced by mica strips, on which were deposited bright metallic platinum. By shielding the vanes on one side, their rotation was obtained, as the action of the electric waves produced oscillating currents in the metal, which perceptibly heated it owing to its ohmic resistance, and thus gave rise to the wellknown radiometer action. The short electric waves were generated by means of a Hertzian doublet with minute tungsten cylinders substituted for platinum. The wave-length measurements involved the use of a new form of reflecting echelon analyser.

By means of the equipment briefly sketched above, Nichols and Tear were able to produce and measure electric waves down to 0.220 mm. in length, which is

shorter than the longest known heat waves emitted by matter at high temperatures." In a check experiment on the apparatus, these investigators exposed their electric-wave receiver to Rubens' and von Bayer's heat waves of 0.320 mm. in wavelength, and obtained results identical with those recorded by these earlier investigators."

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The range represented by the shortest wave-length, that of gamma rays (y rays) from radio-active matter, to that of the longest Hertz waves, is now practically ex plored throughout. The ratio of the shortest wave-length to the longest wave-length is about 1 to 20 million billion.

"Matter under the action of heat is capable of giving off radiations in the so-called infrared, visible, and ultra-violet spectra ; gamma rays are the natural accompaniment of radio-active disintegration, and there are various electric phenomena in the atmosphere giving rise to pulse-like disturbances resembling fragments of very long electric waves. But X-rays and the old and new short electric waves we may still regard as artificial, or purely products of laboratory manufacture.'

THE INSTITUTE OF PHYSICS. At the last meeting of the Board the following Corporate Members were elected:Fellows C. H. Desch, M. Fishenden, W. M. Jones, S. Marsh; Associates: R. P. Black, M. Brotherton, J. F. Congdon, D. E. Jolin, H. Lowery, S. P. Peters, L. J. Sutton, N. W. Turnell, A. Whitaker, L. Wright.

THE BRITISH DYE INDUSTRY. During a recent debate on the Board of Trade vote in the House of Commons, Mr. Clayton, the Unionist member for Widnes, referring to British dyes, said that we had all the raw materials for the dye industry in this country, and there was no reason why those dyes which were made before the war in Germany could not be made here. Enormous progress had already been made, and the dye-users agreed that under the help and guidance of the present Board of Trade they would yet establish a dye industry in this country which could hold its own with any other. The intermediates for these dyes were necessary for explosives, and if the dye industry was maintained in this country we should have valuable materials at our disposal in case of emergency. fore the war in Germany it was part of the Army manœuvres to turn the dye-works into explosive factories. He maintained that the chief opposition to this subsidy came from the merchants who supplied German dyes.

Be

STUDIES ON THE PHYSICAL FOUNDATIONS OF DEEP THERAPY TREATMENT.

BY PROF. DR. FRIEDRICH DESSAUER (Director of the Institution for the Study of Physical Laws of Medicine, University of Frankfort, Frankfort-on-the-Main, Germany.)

STUDY OF THE PYHSICAL CONDITIONS.

The paper dealt first with the physical laws of irradiation and the exact knowledge of the distribution of the rays within the tissues.

The second line of study covered the technical requirements for a practical solution of the problem. I have been working in Germany on the development of the apparatus, and have spent many years of thought on producing one that would generate very high voltages and would operate continuously without change under conditions of absolute safety and within small dimensions; that is, an apparatus which could be used by the medical man without danger and without great expense for operation and upkeep. In the meantime my friend and co-worker, Dr. W. D. Coolidge, has still further developed his wonderful tube, with which I could obtain the

Sir P. Lloyd-Greame, President of the Board of Trade, said that the value of the dye industry to the textile industry of this country was greater than ever before. The occupation of the Ruhr had taken place, and great uncertainty existed as to whether the dyes would come forward at all. He knew one company which had been manufacturing day and night almost since the occupation to supply the things that were needed. The textile trade would have been in a very anxious position in the last six months if it had existed entirely on dyes coming from the Continent. It had been said that the dyes that were being used in Lancashire were bad, but the Chairman of the DyeUsers' Association had paid a tribute of admiration to the makers for the progress achieved in the production of dyestuffs in the last few years. Our pre-war consumption of German and other foreign colours was 70 to 80 per cent. of the total, and last year we used 70 to 80 per cent. of British dyes, this change having been effected without in any way reducing our standards.

most accurate results, and with which I could bring to their best effect the high voltages. This subject will be covered in my second paper.

Before arriving at my last results, I shall briefly touch upon the history of how the problem started. In 1904, nearly seventeen years ago, I first formulated the problems. At that time superficial skin diseases were being treated with Röntgen rays. The results were not satisfactory, and Professor Perthes published interesting experiments. coming to the conclusion that an insufficient quantity of rays penetrate to a depth. I naturally approached the problem from the physicist's point of view.

The Laws of Homogeneous Irradiation were the foundation for the development of deep therapy, and have to-day proven to be true. To-day it is very simple and natural, but it was not so seventeen years ago, when the nature of Röntgen rays was unknown and their laws could not have been known. Amongst those who had grasped at the first the importance of the physical laws of deep therapy and had made use of them consciously, I should like to mention Beclère of Paris and Wetterer of Mannheim.

The laws of homogeneous irradiation are. in abbreviated form the following:

First Law. The foundation of Röntgenotherapy is formed by the biological ex

perience that different cell forms show different sensitiveness to the same Röntgen

rays.

Second Law.-Rays of different penetration are to be regarded as different medicaments, so long as the contrary is not proven. The difference in sensitiveness of different cells appears more marked if hard rays are applied.

Third Law.-In order to determine and utilise precise differences in sensibility, the homogeneity of the field of radiation is a required condition.

Fourth Law. The non-homogeneity of a treated field detracts from the effect. The conditions for a favourable influence upon the disease are not fulfilled when the nonhomogeneity of the field is greater than the difference in sensitiveness between the diseased cells and the healthy.

This law, the law of the limit of effect, can easily be expressed by algebraic formulæ.

Fifth Law. There is a homogeneity of space or quantiative homogeneity and a specific homogeneity, or qualitative homogeneity. The aim must be to dose the diseased zone throughout its extent with the needed quality or dose of irradiation, and to have this dose of the same quality through

out.

Sixth Law. The condition of qualitative or specific homogeneity is fulfilled when the irradiation in the complete zone during its course through the body does not change its composition or consistency. The reaction on the different cells is then physically only dependent on the intensity and the time.

Seventh Law. The intensity of effect may not differ more than the degree of sensitiveness. This is only a more precise statement of the fourth law, the limit of effect, but one may try to increase the intensity on the diseased zone in the depth and to raise it above the intensity on the surface, and in the vicinity of diseased cells.

Having a well-known composition of rays we have measured the distribution of the intensity of irradiation within a body. These measurements have been made with four kinds of rays-the most penetrating which up to then could have been produced continuously. Five focal distances were studied each for three different-sized treatment fields-small, medium, and large.

(From The American Journal of Roentgenology," Vol. VIII., No. 10, October, 1921, pages 578-588.)

AGRICULTURAL MACHINERY

EXHIBITION AT PARIS.

The Department of Overseas Trade is in receipt of information that the Third Agricultural Machinery Exhibition will be held in Paris in January, 1924.

This exhibition, like those held in 1922 and 1923, will include agricultural machines and implements manufactured in France or in countries which were allied, associate or neutral during the war.

Applications for space will be received up to October 15 next, by the Commissariat General, 8 rue Jean Goujon, Paris (8e).(From the "Board of Trade Journal," July 12, 1923.)

INTERNATIONAL SAMPLES FAIR AT ZAGREB.

The Department of Overseas Trade is informed that the Third International Samples Fair is to be held at Zagreb (Agram), Jugo-Slavia, from April 27 to May 5, 1924.-(From the " Board of Trade Journal," July 12, 1923.)

CANADA.

SURGICAL INSTRUMENTS AND HOSPITAL
SUPPLIES FOR VANCOUVER, B.C.

H.M. Trade Commissioner at Vancouver reports that a firm in that city is desirous of receiving from United Kingdom firms, catalogues, prices, etc., relative to surgical instruments and hospital supplies. Further particulars can be obtained on application to the Department of Overseas Trade (Room 53), 35, Old Queen Street, London, S.W.1.

RAPESEED OIL REQUIRED IN U.S.

Mr. G. Campbell, H.M. Consul-General at San Francisco, reports that a local firm of import and export merchants are desirous of receiving c.i.f. quotations for linseed and refined deodorised rapeseed oil. In the case of the former, the company wish to deal with London exporters alone, and in the case of the latter only with manufacturers.

British firms desirous of receiving further particulars of this enquiry should apply to the same Department. (Reference 20066/ F.W./C.C.2.).

OBSERVATION 1.

When the atomic number is even, the masses of the isotopes are even whole numbers; and when the atomic number is odd, the masses of the isotopes are odd whole numbers; with a few exceptions.

There are 70 numbers given for the masses of the isotopes (not including the doubtful ones in brackets, and excluding also the mass of hydrogen which is not given as a whole number), and of these, 12 are exceptions to the above general rule. If we wish to know whether this general rule contains a truth, we must proceed in the following manner :

The probability that, when the atomic

number is even, the mass of the isotope would accidentally also be even is 1: 2, and that when the atomic number is odd, the isotope would also be odd, is 1: 2. Therefore the probability that the above regularity would happen accidentally in 58 cases out of 70 is 1: 270 +12 = 1: 246 = 1 : 70 billion.

So, the probability that this state of affairs has not happened by accident is 70 billion to one, that is, it is absolutely certain that a truth is contained therein.

Deduction 1.-Therefore, with the advance of knowledge, the exceptions will probably diminish; e.g., the single odd iso

tope of Se may be found later to be an impurity and not Se at all.

Deduction 2.-There is some fundamental and uniform connection between the atomic number of an element and its isotopic masses, and this connection must be expressible by whole numbers.

In the case of Li, whose atomic weight is given as 6.94, and whose isotopes are 7 and 6, it is evident that the majority of the isotopes must have masses of 7. A similar remark can be inade in the cases of several other elements. Omitting those to which such a remark cannot be applied, the figures for dominant isotopes (given in Table I.) are obtained.

This can be seen to be correct by the following consideration. If it were merely a matter of accident, only one out of every four elements would be likely to have 3 evens or 3 odds. Therefore, in 26 elements, 6.5 (=26/4) would be likely to satisfy this condition; so that there would be 19.5 exceptions. (The fact that 19.5 is not a whole number does not affect the reasoning, of course). The probability would then be 426 19'5x4 : 1 4° : 1 = 1: 1, = which

OBSERVATION 4.

The atomic number gives the number of 3's and 1's into which the mass of the dominant isotope can be split up, always commencing with a 3, and taking the 3's and 1's alternately.

E.g., the atomic number of B is 5, and its dominant isotope can be split up into 5 parts, 3+1+3+1+3; the atomic number of Mg is 12, and its dominant isotope can be split up into 6(3+1), i.e., into 12 parts.

This state of affairs continues as far as Ca, when there is an abrupt change, and occurs no more at all in the elements of atomic weight greater than 40.

The probability that there is a truth involved in this observation is infinitely greater than 219 2×3: 1 = 8000 : 1, because it is a complex regularity.

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OBSERVATION 5.

If the mass of the dominant isotope is an even number, the atomic number is obtained by halving it. And, if the mass of the dominant isotope is odd, the atomic number is obtained by subtracting one and then halving the result.

This state of affairs continues again as far as Ca, when there is an abrupt change, and Occurs no more at all in the elements of atomic weight greater than 40.

The probability that there is a truth contained in this observation is 219-2x1: 1 = 130,000 1, for there is only one exception, viz., Argon.

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Deduction 5.-It follows from the last two observations that the majority of the common elements of atomic weight less than 41 are differentiated absolutely from all other elements by some fundamental property or properties. Either this is the case, or the atomic numbers from Fe upwards are wrong. But since chemists are convinced that the properties of all elements are periodic functions of their atomic weights, they cannot admit that there is any fundamental regularity which belongs. solely to those elements which happen to have atomic weights less than 41. Therefore the atomic numbers from Fe upwards must be wrong.

It is not merely extraordinary, but it is also quite absurd, that a complex general rule connecting the atomic weight with the atomic number should apply only to those elements which happen to have atomic weight less than 41, and which also happen to include nearly all the common elements.