Water is a problem in that section of the fields which is removed some distance from the Olifants River, and there is, also, some risk of malaria. Mica mining, however, is an industry that does not require much water, and arrangements can be made for domestic requirements. In so far as malaria is concerned, good houses, mosquito screened, and decent living, will make the conditions of life in the sub-tropical climate comfortable and healthy.

The mica occurs in pockets scattered throughout the pegmatite. The pockets are sometimes of considerable size, running occasionally into cubic yards, which contain numbers of 99 "books or mica which, when trimmed up, yield sheets of mica of excellent quality.

Much of the mica which has been opened up so far in these fields is of a pale olive green colour.

Some of the occurrences, however, yield a pale brown mica, and others a nearly colourless product.

Considering its extent and resources the field may be said to be practically untouched. A few occurrences have been worked in a small way, but for want of organisation in mining, dressing, and marketing it has not so far yielded any great quantity of mica. The waste or scrap mica of the pale green variety is beginning to enjoy much popularity among mica grinders, the product being a very fine, lustrous

one.

There seem to be good reasons for thinking that if this field, with its many occurrences of mica, were explored and developed it will yield many of the different classes of grades of mica demanded by different industries which use it.

TALC.

There are numerous occurrences of talc also, as in the case of chrysolite and magnesite, in the Jamestown Series of the Transvaal System. The best development that have hitherto been opened up lie in the same locality as the magnesite near Kaapmuiden Railway Station, in the Barberton District, some 93 miles from the port of Delagoa Bay.

Machinery for the treatment and grinding of tale has just been erected for the first time in South Africa, and production has started; the ground product is said to be of excellent quality. The tonnage available from this source of supply is very considerable.

The following is a typical analysis:

The above review has been limited to those minerals which occur in such quantity and are of such quality as to suggest that they hold out commercial possibilities.

Certain other minerals, however, also occur, though on a smaller scale, these being arsenic, bismuth, graphite, iron pyrites, lead, iron-oxides, ochres, osmiridium, scheelite, soda, tungsten, vanadium, and zinc. Some of these are even worked in a small way.

The financial resources of the Union have not so far permitted of the completion of the geological survey of the whole country, but considerable tracts have been so surveyed and these are constantly being added to by a small but efficient staff.

GENERAL NOTES.

KODAK INVENTOR SUGGESTS
CALENDAR CHANGE.

That business could be run with less money and turnover increased by a change of calendar is the opinion of Mr. George Eastman, the founder of the Kodak Company. Mr. Eastman argues that business would benefit by a substitution for the present calendar of one of thirteen monthseach of four equal weeks-because there would be thirteen monthly settlements during the year instead of twelve and consequently a faster turnover. The same

volume of business could be handled with less capital.

Easter could be fixed with benefit to certain businesses. All months would be comparable without adjustments being made for unequal number of days or weeks, and a great amount of clerical work would be eliminated in the preparation of amounts and statistical reports.

Lapse of time for interest and other purposes could be calculated more easily, and a month of exactly four weeks would obviate many of the adjustments now necessary between four and five-week months. every month-end would coincide with the

Also,

week-end-most convenient for business, rents, and general affairs. Fractions of weeks at month-ends would cease.

The scheme would mean thirteen months, each of twenty-eight days. The first of the month would fall on a Sunday, and one would be able to tell the days of the week by the date. An extra month, called "Sol," would be inserted between June and July, and the odd day in the year would be called "Year Day."

It is estimated that thirteen monthly settlements instead of twelve would mean that two billion more dollars would be available for business expansion in Europe and five billions for the world.

American business men are said to be almost unanimous in favour of the new calendar. A questionnaire sent to 1,000 of the leading firms brought favourable replies in almost every case. Mr. Eastman recently called at White House to discuss the plan with President Coolidge.

FIRE WITHOUT SMOKE.

CAMPAIGN AGAINST AIR POLLUTION IN THE GREAT CITIES.

A LORD MAYOR'S LEAD.

Following on the passage into law last year of the Public Health (Smoke Abatement) Bill, real efforts are at last being made to tackle the smoke problem of our great cities.

Co

The Act provides for the appointment of regional committees for the purpose of enabling local authorities to take ordinated action over wide areas against smoke pollution. Under the auspices of the Coal Smoke Abatement Committee of London, working in conjunction with the Smoke Abatement League of Great Britain, a conference has been arranged to take place at the Manchester Town Hall on March 8 at which practical stages for the carrying out of the provisions of the Act will be discussed. It is hoped that Sir Napier Shaw, the well-known meteorologist, who is president of the League, will preside.

Simultaneously, several Northern cities are seriously concerning themselves with the smoke pollution from domestic chimneys which, though not dealt with in the Act, is held by experts to be responsible for the greater part of Britain's vast output of atmospheric soot and dirt. The Manchester Public Health Departient is pursuing inves

tigations with various forms of smokeless domestic fuel, with a view to making recommendations for the reduction of raw coal burning, while at the Sheffield Town Hall experiments were recently made in order to test the possibilities of the residual fuel of low temperature carbonisation of coal, which has recently been established on a commercial basis at Barugh, near Barnsley.

Sheffield and Rotherham have formed the first Joint Regional Smoke Abatement Committee under the new Act, and the chairman (Councillor W. Astbury), reporting on a recent test made over a period of three days in an ordinary domestic Yorkshire range, with coalite, the low temperature carbonisation residual fuel, summarises the results as follows:

(1) Much cleaner than coal in every way. (2) Gives greater heat than the best house coal.

(3) More economical, lasting longer and waste content negligible.

(4) No smoke.

The Co-operative Society in Sheffield is recommending its 50,000 members to assist in the prevention of smoke pollution from domestic chimneys by burning low temperature fuel, and seventy branches are assisting in the distribution of this fuel. The chairman of the Health Committee has appealed to all citizens to burn smokeless fuel, and, in company with the Lord Mayor and the Medical Officer of Health, he is setting a personal example to the citizens.

UNITED STATES AUTOMOBILE
MANUFACTURERS TO DEVELOP
BRITISH COLUMBIA CHROMIUM
DEPOSIT.

The Arctic chromium deposits on the Bonaparte River, 23 miles north of Ashcroft, British Columbia, have been acquired by Detroit automobile manufacturing interests, represented by Mr. Charles C. Bush, of the Ford Building, Detroit. The property was owned by Mr. A. C. Cooper, of Victoria, and Mr. Charles F. Law, of Vancouver. Staked by these men years ago, it was worked by the Imperial Munitions Board during the war, when chromium was in great demand. Mr. Bush obtained the property by a sales agreement over offers by General Motors and the Consolidated Mining and Smelting Company of Canada. Chromium is becoming an in

creasingly important metal in industry and is now being used in the automobile industry as a substitute for nickel.

NOVA SCOTIA BLAST FURNACES
CREATE NEW RECORDS.

All production records of the Dominion Iron and Steel Company were broken by blast furnaces Nos. 1 and 4 during December. No. 1 furnace produced a daily average of 514.7 tons of iron, as against the best previous high output of 490 tons attained earlier in 1927, while No. 4 blast furnace turned out a daily output of 351.4 tons, which is ten tons a day better than any previous mark. The output of No. 1 furnace was about 25 per cent. higher than in 1924, which was also a high production period.

INSTITUTE OF METALS
TWENTIETH ANNUAL MEETING.

OPENING OF NEW OFFICES.

The twentieth Annual General Meeting of the Institute of Metals, which will be held in London on March 7 and 8, at the Institution of Mechanical Engineers, Storey's Gate, Westminster, will include several interesting functions. Thus the new President, Dr. W. Rosenhain, F.R.S., will be inducted into the chair by Sir John Dewrance, K.B.E., and will deliver his Presidential Address. Afterwards sixteen papers will be read and discussed. These include contributions from metallurgists in Germany, Japan and the United States, as well as Great Britain. Following the papers, there will be a dinner and dance at the Trocadero Restaurant, also the formal opening of the new offices and library of the Institute, at 36, Victoria Street, London, S.W.1. The official programme of the Meeting includes a notable list of new Members-123 in all-which brings the Membership close to the 2,000 mark. It is striking to note what a large proportion of the new Members reside abroad. An election of Members is announced to take place on February 22; particulars of Membership, which now covers the period ending June 30, 1929, are obtained from the Secretary, Mr. G. Shaw Scott, M.Sc., 36, Victoria Street, London, S.W.1. Among the latest applicants for membership are M. André Citroën, the famous French motor car maker, and representatives of the French Mint and Ministry of Marine.

ANALYSIS OF FERTILISERS.

The Council of the Institute of Chemistry, after careful consideration of the whole of the circumstances, has drawn up the following proposals with regard to the remuneration, under the new Act, of those Official Agricultural Analysts, who are paid by fee per sample, feeling that in so doing they will have helped to give guidance to local authorities as to the fees that will be generaily regarded by the chemical profession as fair and reasonable. It will be seen that in this scale, regard has been had to the fact that the extent of information required in an analysis varies according to the commodity.

The scale recommended is as follows:

(1) For analysis of a fertiliser or feeding stuff where the determination of a single item only is required-not less than £1 1s. Od. per sample.

(2) Where a determination of two separate items is required-not less than £1 11s. 6d. per sample.

(3) For fuller examination, according to the complexity of the analysis required

£2 2s. Od. to £3 3s. Od. per sample.

Observations were made to examine the part played by (a) point-discharge currents, (b) lightning discharges between cloud and ground, and (c) charged rain, in the electrical interchange between an active thundercloud and the earth. From these observations, (a) and (b) are estimated to produce continuous currents of the order of 2.1 and 0.1 (equivalent) amperes respectively, in an upward direction, and (c) to produce a reverse downward current of the order of 0.2 amp. The resultant current is thus estimated at 2.2 amps, in such a direction as to convey a negative charge to earth.

The Thermal Conductivities of Oxygen and Nitrogen. By H. GREGORY AND S. MARSHALL. Communicated by H. L. Callendar, F.R.S.

The thermal conductivities of these gases at 0° C. are investigated. The apparatus used was the vertical compensated hot-wire type employed by the authors in their determination of the thermal conductivity of carbon dioxide.

The object was to confirm the result obtained by Gregory and Archer for air, on account of the wide discrepancy which exists among results obtained for conductivity of this medium by various observers.

Procedure was same as in case of investigation of Co2, except that an alternative method was used for determining fundamental intervals of platinum wires, a problem approached from point of view of thermal conduction through the gas.

The results are given as 589 × 10- cal. cm. sec. deg.-' for oxygen, and 580 × 10- cal. cm.-' sec.-' deg.-' for nitrogen, at 0° C., and are consistent with those of Gregory and Archer for the thermal conductivity of airat 0° C.

On a Method of Determining the State of Polarity of Downcoming Wireless Waves. By E. V. APPLETON, F.R.S., AND J. A. RATCLIFFE.

Recent observations on the effects of the atmospheric ionised layer on wireless transmission have shown that downcoming wireless waves of 300-500 metres wave-length possess components of electric force both in and at right angles to the plane of propagation,, but information on the precise nature of the polarisation has been lacking. The paper describes the results of experiments, using a method of determining the polarisation constants of ellipticity of such waves. For down-coming waves of 400 metres wavelength in England the polarisation is found to be approximately circular with a righthanded sense of rotation. In attempting to account for these results it is pointed out that, according to the magneto-ionic theory of atmospheric deflection of wireless waves, in which the influence of the earth's magnetic field is taken into account, such righthanded elliptical polarisation might be expeated if the effective electrical carriers are of electronic mass.

On the Measurement of the Specific Heat of Aniline with Temperature, Using the Continuous-Flow Electric Method. By H. R. LANG. Communicated by H. L. Callendar, F.R.S.

New experiments on variation of specific heat of aniline with temperature have been carried out by the continuous-flaw electrical method. Experimental details are described and possible sources of error investigated. Two types of flow calorimeter were used, giving results in close agreement, although in one case a convection correction had to be applied. Care was exercised to use only pure aniline. It was found extremely difficult to get the liquid perfectly dry, as it was hygroscopic. The very small water-content was determined in each case from the freezing-point. A separate investigation gave relation between water-content and freezing-point, a small correction being applied to give value for perfectly dry aniline.

Between 5° and 75° C. rate of change of specific heat with temp. was found to increase with rising temp. Experiments were also performed at temps. below 5° C., but owing to rapid increase of viscosity, values are rendered less certain in this region.

An X-ray Study of Some Simple Derivatives of Ethane. Part I. By K. YARDLEY. Communicated by Sir William Bragg, F.R.S.

The substances C,Cl, C.Br, C,Cl, Br, (two forms), C,Br,F, C,Cl, Br, C,Br (CH3)2 (two forms), form an isomorphous series, crystallising in the space-group Q. The unit-cell contains four plano-symmetrical molecules. Two halogen atoms and the two carbon atoms lie in the symmetry plane (010). The molecules of C,Cl, C.Br. and C.Br,(CH,) also possess a pseudo-centre which produces additional halvings not expected from space-group considerations.

From the molecular symmetry the symmetry of the carbon valencies is deduced and it is shown that the carbon atom possesses two A and two B valencies, possibly identical with the two (2, 1) and two (2, 2) electrons in the outer group of neutral carbon.

6

Composite F curves obtained for C,Cl and CBr are compared with Hartree's curves for Cl- and C4+. The formula of both forms of C,Cl, Br, appears to be CC. CCIBr. The two CH, groups in C.Br, (CH); lie in the symmetry plane.

THE CHEMICAL SOCIETY..

Papers read on Thursday, February 2 :Some Experiments on Diffusion in Solid Metals. By J. W. JENKIN AND C. H. DESCH.

The two metallic systems examined were copper-nickel and copper-zinc. Smooth, rectangular specimens of the one metal were coated electrolytically with the other metal, and the progress of diffusion was measured by cutting sections after definite periods at a given temperature and observing by means of the microscope. The phases of the copper-zine system are sufficiently distinguished by colour, whilst the copper-nickel alloys have to be etched and compared with a trial plate made by clamping together a series of alloys of progressively varying composition, and comparing the distance to which etching proceeds under given conditions. The observed diffusion curve is the resultant of two curves of similar mathematical form representing diffusion in two opposite directions, and it is possible to arrive at approximate values for the two coefficients. Thus the diffusion of copper into nickel is about twenty times as rapid as that of nickel into copper. In the brasses, the production of a sharp boundary accompanies the formation of an intermetallic compound. A difference of 25 per cent. in the concentration of the outer and inner portions of a cored crystal of cupro-nickel has been determined to exist as the result of incomplete diffusion during solidification.

The Alkaloids of Some Indian Aconites: Aconitum rotundifolium, A. Balfourii, and A. deinorrhizum. By T. A. HENRY AND

T. M. SHARP.

tains one methoxyl group less than the parent alkaloid, but retains the methylimino-group of the latter.

The Synthesis of meso-Alkyl and mesoAryl Anthracene Derivatives. Part III. By E. de B BARNETT AND J. W. Cook.

1:

The action of Grignard solutions on dichloro-9-benzylanthrone, 9: 9-diphenylanthrone and 9: 9-dibenzylanthrone has been examined. The resulting dihydroanthranols have usually given methylene derivatives on dehydration,

although in two cases transannular loss of water was effected. The facile production of methylene derivatives from compounds obtained by the action of magnesium alkyl halides on diphenylanthrone renders it improbable that the formation of methylene compounds in other cases is due to a transannular migration of hydrogen under the influence of hydrogen ions. Previous indications that an alkyldihydroanthranol can undergo trans annular loss of an alcohol have now received confirmation by the formation of 9 10-dibenzylanthracene from 9: 10tribenzyldihydron anthranol.

Treatment of 1: 5-dichloranthrone with benzyl chloride and potassium hydroxide yielded 15-dichloro-8-benzylanthrone (which could not be acetylated or methylated), whereas 1-chloro-9-anthrone, like anthrone itself, readily yielded a dibenzyl compound. The inhibiting effect of the a-chlorine atoms appears to be a general phenomenon in connection with the reactions of 1: 5-dichloroanthracene and its derivatives.

SOCIETY OF GLASS TECHNOLOGY.

The first meeting of the Society of Glass Technology for the year 1928 was held in the College of Technology, Manchester, on Wednesday, January 18, the President, Walter Butterworth, Senr., in the chair.

Discussions took place on the following subjects:

The Design and Operation of Glass Furnaces.

The discussion on this subject was introduced by Mr. W. M. Warren, A.M.I.C.E., A.M.I.E.E., who compared a boiler plant with a glass furnace system. The most important development in boiler plant had been the substitution of the Lancashire boiler by the water tube boiler. The latter had a high rate of heat transmission and a