ws the Tube in the Shiel

The “INCANDANODE” TUBE

(so called because it works all day with the Anode RED HOT). This Tube ran from 9 a.m. to 6 p.m. for five days at the Leicester meeting of the B.M.A. last July, The Anode was incandescent the whole time, but the Vacuum was fully maintained. One Tube will last for years. The Vacuum is easily adjustable THE BELOT SHIELD FOR X-RAY

WORKERS. MR. HALL EDWARDS (at the Leicester meeting of the B. M. A. last July) said of this shield :-" It is a scientific instrument designed on scientific lines, and overcomes all the objections which exist in the shields previously brought to my notice.” THE MEDICAL SUPPLY ASSOCIATION,

228 GRAY'S INN ROAD, LONDON, W.C.

Descriptive Circulars (with expert testimony) op application. INTENSIFIED

ASSOCT

Illustration

INDUCTION COIL.

Specially designed for X-Ray Work, &c.

FULL PARTICULARS ON REQUEST TO

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313 High Holborn,

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AND AT

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SPIN THARISCOPES.

(As devised by Sir WM. CROOKES.) Showing the Scintillations of Radium. Fitted with powersul Lens, and contained in neat Leather Case.

Price 15 - Post Free anywhere. The scintillations seen in this instrument are from Pure Radium Bromide of the highest known activity, and are brighter and more plentiful than those produced from Pitchblende or any other radio-active substance.

PS See letter from Prof. Goich on "The Spinthariscope and Retinal Excitability” (NATURE, June 22, 1905, page 174), setting forth a valuable scientific application of the instrument. (15/- per lb. Thorianite

4/- per oz. Calcium Metal

11/3 per oz.

Radium Bromide from £16 per 5 mgs. A. C. COSSOR, 54 Farringdon Road,

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St. Louis Exhibition.

THE

STIGMATIC LENS.

SERIES II. F/6.
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combination may be used separately, giving foci of about Is and 2 times the length of that of
the lens when used intact. The advantage of thus being able to choose the best point of view,
irrespective of distance, will be at once apparent to the artistic worker.
EQUIVALENT TO FOUR LENSES AT THE PRICE OF ONE.

Eleven Sizes are now ready, from 34 to 18 inches eq. focus.
CATALOGUE OF HIGH-CLASS CAMERAS AND LENSES, POST FREE.

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MAKERS OF THE CELEBRATED DALLMEYER LENSES.
Frinied by RICHARD CLAY AND SONS, LIMITED), at ; Lieac Sureer hil, Queen Victoria Sucel, H. in: uit. o! JU , alu). by A.

1

A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE

“ To the solid ground
Of Naturo trusts the mind which builds for aye."— WORDSWORTH.
No. 1917, VOL. 74)
THURSDAY, JULY 26, 1906

[PRICE 15 CENTS Registered as a Newspaper at the General Post Office.)

(All Rights are Reserved.

REYNOLDS & BRANSON, Ltd., NEW PATTERN APPS-NEWTON PORTABLE COIL, Chemical and Scientific Instrument Makers to His Majesty's As supplied to the Indian Government, &c.

Government (Indian, Home, and Colonial).
Price

LABORATORY FURNISHERS and MANUFACTURING CHEMISTS.

£30 оо

NEWTON & CO.,
Scientific Instrument Makers to H.M. the King and H.R.H. the

Prince ot Wales and the Government,
3 FLEET STREET, LONDON.

CHEMICAL AND PHYSICAL BENCH, illustrated above, as supplied" to National Physical Laboratory, Teddington, fitted for Gas, Water

and Electricity.
Catalogue of Chemical and Physical Ápparatus, 350 pp. and 1200

Nlustrations, free on application.
DESIGNS OF BENCHES AND FITTINGS TO SUIT ALL REQUIREMENTS.

14 COMMERCIAL STREET, LEEDS.

NEGRETTI & ZAMBRA'S THERMOMETER

ANEROID
MAGNIFIERS.

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38 Holborn Viaduct,

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45 Cornhill;

6000

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EGYPTIAN GOVERNMENT.

MINISTRY OF EDUCATION.
The following post at the School of Medicine, Cairo, is vacant :

ASSISTANT TO THE PROFESSOR OF CHEMISTRY.
The appointment is for two years, and may be renewel at the end of that
time. Applicants should forward copies of testimonials and such other
particulars as are mentioned below.

The 1 ay of the past is LE. 320 per annum, the Egyptian Pound being worth 6d more than the Pound Sterling.

Private Practice is not allowed.

It is to be distinctly understood that the appointment gives no claim to pension or indemnity.

The Government reserves to itself the right to dismiss the assistant for misconduct or incapacity.

In the Government Schools, as in all State Administrations in Egypt, Sunday is a working day. The Schools are closed on Fridays.

Leave will be granted on the same terms as to other Government Officials. The possibility of taking leave, and the period of the year at which it is granted, depend upon the exigencies of the service

Pay commences from date of arrival in Cairo. On taking up his duties in Cairo, the Assistant will receive one month's pay in lieu of passage money:

All applicants ould attach a certificate from a legally qualified medical
man, stating that in his opinion the candidate would pass as a first-class
life for insu ance purposes.
All applicants should state :

Their training and qualifications in Analytical Chemistry,
Their age,
What foreign languages they know, and

If they can be in Cairo by October 1.
The latest mail by which applications may be posted will leave London
on Friday, August 31. Applications to be addressed :-THE DIRECTOR,
Government School of Medicine, Cairo, Egypt.

THE VICTORIA UNIVERSITY OF

MANCHESTER.

SESSION 1906-7.
The SESSION will commence on TUESDAY, OCTOBER 2 next.

The following prospectuses may be obtained on application to the
RegistRAR :-)

Faculties of Arts and Science.
Faculty of Medicine.
Faculty of Law.
Faculty of Music.
Faculty of Commerce.
Faculiy of Theology.
Faculty of Technology.
Department of Education.
Department of Engineering.
Department of Mining.
Department of Architecture.
Advanced Studies in the Faculty of Arts.
Instruction in Military Subjects.
Dental Department.
Pharmaceutical Department.
Public Health and 'Veterinary State Medicine.
Fellowships, Scholarships, Exhibitions, &c.
Evening Classes and Popular Courses.

TO SCIENCE AND MATHEMATICAL

MASTERS.-September Vacancies. ---Graduates in Science and other well qualified Masters seeking posts in Public and other Schools should apply at once, giving full details as to qualifications, &c., to Messrs. GRIFFITHS, SMITH, POWELL & SMITH, Tutorial Agents (Estd. 1833), 34 Bedford Street, Strand, London. Immediate notice of all the best vacancies will be sent.

THE GOVERNMENT OF CEYLON

HARPER-ADAMS AGRICULTURAL require a LECTURER in PHYSICS and a LECTURER in CHEMISTRY for the Colombo Medical and Technical Colleges.

COLLEGE, Salary for each post, 6400, rising by annual increments of 625 to 2500 a ycar

NEWPORT, SALOP. The Government also require a SCIENCE MASTER for the Royal College, Colombo, to teach Chemistry and Physics for London Uni. LECTURER IN MATHEMATICS AND LAND.SURVEYING. versity Pass Examinations, including the Intermediate B.Sc. Salary, £350, rising to £450 by annual increments of £25.

Applications are invited for the above Lectureship on or before August 12. For the above appointments preference will be given to graduates in The Lecturer will be required to enter upon his duties on October 1, 1906. bonours of any British University, under the age of 35.

Full particulars can be obtained on application to ihe PRINCIPAL. Salaries are subject to a deduction of 4 per cent. as contribution to the

Widows' and Orpbans' Pension Fund. Free passages to the Colony. Leave and pension on same terms as to Salaries £400 to £500, £350 to £450, and other officers of the permanent service.

£300 to £400. 20 Science Graduates for Public Colleges, England Applications should be sent before August 15 to the Assistant PRIVATE SECRETARY, Colonial Office, S.W., and envelopes should be marked

and Abroad Also Woodwork vacancy, 6150. List of Science and with the name of the post applied for. Copies only of testimonials Mathematical Vacancies sent to all Candidates. (not more than six).

OR EL LA NA & CO. DARTFORD TECHNICAL can guarantee each candidate with good references an appointment. No

fee till suited.
INSTITUTE.

Estd. over 50 YEARS.
CHEMICAL DEPARTMENT.

80 WIGMORE STREET, LONDON, W. EVENING CLASSES. The Committee invite applications for the post of TEACHER of COACHING.-Gentleman with London CHEMISTRY (Theoretical and Practical), who may be required to give University diplomas in Applied Science wishes to coach gentlemen instruction on four evenings per week for about three hours per evening.

reading for examinations in mathematics, electrical and mechanical

engineering, and allied subjects, at their own residence or place agreed Salary. £go per Winter Session of about 30 weeks.

upon. Apply by letter to · EQUATION," c/o Smith's News Agency, Applications should be forwarded not later than August 11 to Mr. D. F.

Worcester Brow, Technical Institute, Dartford, Kent, from whom further particulars may be obtained.

Experienced Lecturer, young, tall, wishes

for engagement round Birmingham or Worcester for the following UNIVERSITY OF BIRMINGHAM.

subjects :-Mathematics, Electrical Engineering, and Applied Physics. Apply by letter EQUATION," c/o Smith's

News Agency, LECTURER IN ZOOLOGY.

Worcester. The Council invites applications for the appointment of LECTURER in ZOOLOGY

For other Scholastic Advertisements, see page cx. Stipend, 4150 per annum.

Particulars and conditions of the appointment may be obtained on application to the SECRETARY. Applications, giving particulars as to qualifications and experience, with

For Sale, a unique Collection of Minerals, six copies of recent testimonials, must be sent to the SECRETARY on or some 300 specimens, and catalogue. Can be seen by appointment. – before July 31, 1906.

Address W. TRURAN, 168 Richmond Road, Dalston, London, N.E. GEO. H. MORLEY, Secretary.

to

UNIVERSITY COLLEGE OF SOUTH
WALES AND MONMOUTHSHIRE,

CARDIFF
The Council of the College invites applications for the post of DE-
MONSTRATOR and ASSISTANT LECTURER in BOTANY.

Further particulars may be obtained from the undersigned, by whom applications with testimonials (which need not be printed) must be received on or before Saturday, September 1, 1906.

J. AUSTIN JENKINS, B.A , Registrar.

PROTECTION from MOSQUITOES

AND OTHER INSECTS. ARMBRECHT'S PYRETHRUM. Ten drops to a tablespoonful of water and sponged over expound

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ARMBRECHT, NELSON & CO. 71 & 73 DUKE STREET, GROSVENOR SQU