2-186 cc. gives a value of 127 for kuλ, which should be for that volume 32:43. For their Experiment VI. in a volume of 4.996 cc. kμlλ = 6·9, but should be 16:03.

Further values for M/N for other gas reactions calculated from the data of Cameron and Ramsay are probably in error by a similar amount, but it would hardly be safe to assume and use a correction factor. The experiments themselves should be repeated, which the writer hopes to be able to undertake in the near future.

Any discussion of the possibility of giving theoretical significance to the M/N value of 3.92 will be reserved for the conclusion of the next paper, Part II.

10. Summary.

The foregoing experiments on the combination of hydrogen and oxygen gases at ordinary temperatures under the influence of radium emanation mixed with the gases in spherical vessels of different diameters show:1. The velocity of reaction in a given volume is dependent on two variables only, the quantity of emanation E and the gas pressure P. The velocity constant obtained by integration of the equation arising from this assumption has been verified. Its torm is

const. (log P/Po)/E.(e-λt-1).

2. The effect of increasing the spherical volume is to diminish the velocity constant (expressed in terms of pressure) according to the equation, const = 84'1/D2, where D is the diameter in cm. This is to be expected from the increase of the average path of the a-particle proportional to D, while the pressure effect diminishes proportional to D. This formula is applicable only to spheres in which the size of the shortest a-ray is not exceeded by the diameter. 113. Varying proportions of hydrogen and oxygen changes the velocity as would be expected from the changes produced in the specific ionisations (H2 = 0·24, O2 = 1'09 referred to air = 1). Excess of oxygen gives a velocity higher than normal and which increases as the proportion of oxygen increases. Excess of hydrogen produces the opposite effect.

4. From No. 3 it follows that the emanation activates both of the pure components.

5. The temperature coefficient of the reaction between 0° and 25° is zero, as would be expected from ionisation. 6. Calculation of the ionisation by the method of average path of the a-particles shows that for each pair of ions produced in the gaseous mixture about 3'9 molecules of water are formed. (Scheuer found 3.7). Theoretical interpretation of this is deferred to the next paper.

7. Reaction in cylindrical volumes obeys the same law as in spherical ones, appearing to confirm the writer's earlier claim that the average path in the cylinder is the same as in sphere of equal volume.

The writer desires to thank Dr. R. B. Moore, Dr. Herman Schlundt, and Mr. J. E. Underwood for their advice and assistance in carrying out the foregoing experiments.

THE Chinese Manganese Mines Association, 39, Szechuen Road, Shanghai, China, represents the three largest manganese mines in China, and wants information regarding markets in England for exporting the same. The analysis of the manganese ore from one of the mines is as follows:- Manganese, 52.52 (per cent); combined water, 3.82; iron, 390; silica, 5'14; sulphur, 0049; phosphorus, 0'419: copper, o'023. They also supply chemical manganese in powder or pea-sized form, of which the average manganese dioxide (MnO2) is 75 to 80 per cent. They want to know the present prices in England of manganese ore, both for metallurgical and chemical uses, the standards and other conditions required by the buyers, the annual consumption, and the sources of their supply. They desire to be put into communication with principal

consumers.

PROCEEDINGS OF SOCIETIES.

-

ROYAL SOCIETY.

Ordinary Meeting, June 26, 1919.

Sir J. J. THOMSON, O.M., President, in the Chair.

The following papers were read: :"Monoclinic Double Selenates of the Cobalt Group." By A. E. H. TUTTON, D.Sc., F.R.S.

This memoir deals with the four double selenates of the series R2M(SeO4)2.6H2O, in which M is cobalt and R is potassium, rubidium, cæsium, and ammonium. A complete crystallographic and physical investigation has been carried out on parallel lines to the work previously published concerning the magnesium, zinc, iron, and nickel groups, and to that concerning the completed analogous series of double sulphates. The results are in full accord with those derived from the previous investigations. It is an interesting fact that while each group of four salts containing the same M-metal and the four respective alkali bases presents its own absolute values for the various constants, and displays its own idiosyncrasies and individuality, yet the relations of the four salts to each other invariably exhibit the same regularities, gradations, and numerical progressions, even to the most apparently insig. nificant details, each group thus affording an independent confirmation of the truth of the general conclusions. Two dominant facts emerge, namely, (1) the progressive order of all the crystallographic and physical properties, following the progression of the atomic numbers (and, therefore, atomic weights) of the interchangeable alkali metals concerned, potassium, rubidium, and cæsium; and (2) the almost perpect isostructure-that is, congruency, coincidence, and equality of dimensions of the elementary cells of the monoclinic space-lattices-of the crystals of the ammonium and rubidium salts of the group. The progression with atomic number referred to under (1) is completely explained by the operation of Moseley's law, governing the progressive structural complexity of the atoms in accordance with the sequence of the atomic number.

"A New Method of Driving off Poisonous Gases." By HERTHA AYRTON.

"Experiments with Perforated Electrodes on the Nature of the Discharge, in Gases at Low Pressure." By F. W. ASTON, D.Sc.

Experiments are described on the discharge between electrodes of a large flat form perforated with a long narrow slit, the charge passing through the slit being collected and measured in a Faraday cylinder.

Direct measurements made with the Faraday cylinder behind the cathode and at the same potential seem to indicate that about half the total current in the discharge is brought up to the cathode by positive ions.

Attempts to discover the distribution of velocities in this stream show that this is not directly determinable, owing to the very high ionisation in the region of the slit and other reasons, which are discussed.

Using a perforated anode, it is found that as the distance from the cathode is increased arithmetically the current carried by the cathode rays into the Faraday cylinder decreases geometrically when the current is constant.

The effect of (a) the distance apart of the electrodes the last trace of the positive column or Anode Glow is and (b) the total current flowing, on the disappearance of shown to be remarkably definite, but no adequate explanation of this phenomenon seems available at present.

"De Saint-Venant Solution for the Flexure of Cantilevers of Cross-Section in the Form of Complete and Curtate Circular Sectors; and on the Influence of the Manner of Fixing the Built-in End of the Cantilever on its Deflection." By MARY SEEGAR and Prof. KARL PEARSON, F.R.S.

In working out a theory as to the origin of the elements the path is narrow, due to the lack of experimental evidence. Back in 1816, Prout drew practically the same conclusions as stated above except that he considered but one elementary substance-hydrogen. Either of the assumptions, however, can be used in conjunction with the Nebular Theory.

I, too, have assumed hydrogen with its atomic weight of one as a primary substance. As to the nature of the second, some speculation is necessary. It must be a gas to exist in a Nebula, and have an atom weighing three times that of hydrogen.

Sir J. J. Thomson, in his experiments with cathode rays, succeeded in producing a gas with an atomic weight of three. This would be an ideal gas to consider as the second true element. It has been designed as X3, and "consists of three atoms of hydrogen and is represented by the formula H3, bearing, in fact, the same relation to hydrogen that ozone does to oxygen."

If this is the gas sought, Trout's hypothesis still holds good as to hydrogen being the basis of all elements, as X3, a triatomic hydrogen molecule, could then be considered the first product of condensation, and then upon its formation, immediately react with the original bydrogen to form helium and the remaining elements.

That condensation evidently takes place is shown by spectroscopically examining the stars. The hottest stars are of the hydrogen and helium type; another type, some. what cooler, are known as the calcium stars, due to the calcium lines in their spectrum. Other, still cooler, show additional elements, but at no time can all elements present be determined, due to the fact that the spectroscope reveals information pertaining only to the outer envelope of the star.

In the examination of certain nebulæ, three prominent lines are found having wave-lengths of 4861, 4959, and 5007. The first is of the hydrogen series, while the last two, always appearing together and with the same intensity, represent an element which has been called "nebulium." The D3 line of helium is also found in a nebula of this class.

If "nebulium" possessed a weight of three, this kind of nebula would serve as a practical example of my theory, as both primary substances are present as well as the first product of condensation in the form of helium.

In the phenomena of radio-activity it is known that when an element expels an alpha ray it is expelling helium

atoms. Because of this we have reason to believe helium a common constituent of all elements (proof of such being possible to obtain only with those that are radio-active). We also know that the atomic weight of the product is lowered by four. This would naturally take place if the lighter elements had the power to expel helium atoms. Below I have listed the first 16 elements with the "theoretical" numbers assigned them in my previous letter. The reason for listing them as in the Periodic Table is to show that by lowering the atomic weight by four, the valency is lowered by two, as with the radio

He 4 Li 7

RO3

R207

G18 B II C 12 N 15 O 16 F 19 Ne 20 Na 28 Mg 24 Al 27 Si 28 P 31 S 32 Cl 35 Examination of the tabulated table mentioned at the beginning of this letter will show that all of the elements do not coincide with the "theoretical" numbers as well as they might, the irregularity increasing as the weights increase. It is interesting to notice, however, that in most cases where the element does not coincide with the number assigned there is a blank space. Excellent examples are nitrogen at 15 and argon at 36.

In what appears to be the early stages of condensation, the elements were formed in keeping with the theory. As

As men

the weights increase irregularities develop. tioned above, they do not coincide with the theoretical numbers as well. The theoretical numbers cannot be applied to the Periodic Table in the same simple order as in the case of the first score of elements. Calcium is the last element to assume its proper place using the assigned whole number. The next element should be 43 and fall in Group III.; scandium, having a weight of 44, occupies this place.

It is possible that on condensing some elements may have combined with others, forming real compounds, but so bound together that they can only be analysed under conditions similar to those under which they were formed. The fact that argon and potassium, as well as iodine and tellurium, have their places reversed in the Periodic Table almost proves that condensation has not been carried on perfectly. I might add that nickel and cobalt, having such similar properties as well as unusually close atomic weights, have never appealed to me as two cleancut elements.

These remarks will, I trust, at least reveal another point of view in a matter which is as interesting as it is complex.-I am, &c., RAYMOND SZYMANOWITZ.

130, Sherman Avenue, Newark, N.J., U.S.A., July 8, 1919.

NOTES.

ROYAL INSTITUTION. A General Meeting of the Members of the Royal Institution was held on July 7. The Special Thanks of the members were returned to Mr. A. B. Bence-Jones for his present of a crayon portrait by George Richmond of the late Dr. Bence-Jones, Secretary of the Royal Institution, 1860-73. Mr. A. M. Henryson Card and Dr. Edmonds were elected members.

SIR EVAN JONES, Bart., M.P., has found it necessary to resign his position as Commissioner of Dyes in consequence of the heavy duties attaching to the post of Controller of the Coal Mines Department. In future, therefore, all communications referring to dyes should be addressed to the Assistant Secretary, Industries and Manufactures Department, Board of Trade, Gwydyr House, Whitehall, London, S. W. 1.

LIVINGSTONE COLLEGE.-Dr. T. Jays, whose work with the Church Missionary Society and the Student Christian Movement is well known, has accepted the post of Vice-Principal of Livingstone College, where the session will recommence on October 1. Dr. Jays and his wife will be resident in the College, and in addition to helping the Principal, Dr. Wigram, in other ways, will take the lectures previously delivered by Col. G. B. Price. The latter has gained the well-merited honour of C.M.G. for his work in Malta during the war, and is now taking up important work under the Ministry of Pensions to organise and advise on the treatment of discharged soldiers suffering from tropical diseases. It is in consequence of this that he can no longer continue his lectures at Livingstone College, which have been very much appreciated by the students of the thirteen sessions during which he has worked there. Before the college reopens on October I a short course of fifteen lectures on "Personal Care of Health in the Tropics" will be given from September 22-25. Col. Price hopes to be able to take some of these lectures, the others will be given by the Principal and Vice Principal. These lectures are open to men and women, and are intended for those who expect to reside in the Tropics. They would be of use to missionaries, nurses, explorers, members of the services. Government officials, commercial men, &c. The fee for the whole course is 30s., or 38. for a single lecture. Application should be made previous to the lectures to the Principal, Livingstone College, Leyton, E. 10,

James H. Gardiner, F.C.S.

F Established