A WEEKLY 
PAC US RATED) OURNALE OF 
SCIENCE 
To the solid ground 
Of Nature trusts the mind which builds for aye.”—WorDSWORTH 
No. 17] 
THURSDAY, FEBRUARY 
Registered for Transmission Abroad] 
(All Rights are Reserved 
THE ROYAL SOCIETY. — Thursday, 
Feb. 24, at 8:30 p.m. PAPERS to be READ :— 
Dr. STENHOUSE, F.R.S.—Note on Certain Lichens. 
_ Dr. FRANKLAND, F-R.S., and B. F. DUPPA.—On the ‘‘Succes- 
sive Action of Sodium and Iodide of Ethyl upon Acetic Ether.” 
Now complete in 3 vols. medium 8vo., price 63s. cloth, 
A DICTIONARY OF SCIENCE, LITE- 
RATURE, and ART; comprising the Definitions and Derivations of the 
Scientific Terms in general use, together with the History and Description of 
the Scientific Principles of nearly every branch of Human Knowledge. 
Fourth Edition, reconstructed by the late Professor BRANDE, D.C.L., 
F.R.S. (the Author) and the Rey. G. W. COX, M.A.—assisted by Contribu- 
tors of eminent Scientific and Literary Acquirements. 
London: LONGMANS, GREEN, and CO., Paternoster Row. 
LETTERS OF SIR CHARLES BELL. 
Now ready, Post 8vo, Portrait and Woodcuts, 12s. 
A SELECTION FROM THE FAMI- 
LIAR CORRESPONDENCE OF THE LATE SIR CHARLES 
BELL, F-.R-.S. 
JOHN MURRAY, Albemarle Street. 
“ NATURE” PORTFOLIO, TO HOLD 
NUMBERS or PARTS, can be had for Two Shillings of the Publishers. 
This day is published, price 2s. 
A New anp ReEvisrep EDITION, BEING THE FouRTH, OF 
INTRODUCTORY TEXT-BOOK 
PHYSICAL GEOGRAPHY. 
By DAVID PAGE, LL.D., F.G.S., &e. 
Lately published, by the same Author, 
INTRODUCTORY TEXT-BOOK OF GEOLOGY. Eighth Edition, 2s. 
ADVANCED TEXT-BOOK OF GEOLOGY. Fourth Edition, 7s. 6d. 
ADVANCED TEXT-BOOK OF PHYSICAL GEOGRAAPHY. 5s. 
GEOLOGY FOR GENERAL READERS. Second Edition, 6s. 
HANDBOOK OF GEOLOGICAL TERMS, GEOLOGY, AND PHY- 
SICAL GEOGRAPHY. Second Edition, 7s. 6d. 
CHIPS AND CHAPTERS For AMATEUR aND YouNnG GEOLOGISTS. 
5s. 
WILLIAM BLACKWOOD & SONS, Edinburgh and London. 
SHARPEY MEMORIAL. 
Subscriptions towards the Fund for establishinga ““SHARPEY PHY- 
SIOLOGICAL SCHOLARSHIP,” in connection with a “*SHARPEY 
PHYSIOLOGICAL LIBRARY and LABORATORY,” in University 
College, and for procuring a Portrait or Bust of Dr. Sharpey, to be placed 
in that Institution, continue to be received, on behalf of the Committee, by 
the undersigned. 
Sir WM. JENNER, Bart., 63, Brook Street, W. 
JOHN MARSHALL, 10, Saville Row, W. 
J. RUSSELL REYNOLDS, 38, Grosvenor Street, W. 
London, rst Jan., 1870. 
SCHOOL OF CHEMISTRY, 
20, GREAT MARLBOROUGH STREET, 
LONDON, W. 
DrireEcTED BY ARTHUR VACHER. 
IMPROVED MAGNETO MACHINE.— 
“Mr. BROWNING, of the Minories, has just introduced a magneto 
machine of novel form and arrangement, in which the disadvantages of the 
old machines have been completely removed. ‘Two armatures are supplied 
with each machine. With the quantity-armature the following effects can be 
produced :—Half an inch of platinum wire, placed between the poles at E, 
can be made white hot in a few seconds. An induction coil may be made to 
give off bright sparks or illuminate small induction tubes. Bells may be 
rung, or telegraphs worked, even at a distance of many miles. Water or 
chemical salts may be decomposed. With the intensity-armiture, Abel's 
fuzes may be fired, and most powerful physiological effects may be produced. 
‘The power of the shock-current may, however, be modified to any extent at 
the wlll of the operator. For any purpose, the effects of a moderately-power- 
ful voltaic battery may be produced, without the trouble and inconvenience 
attending the use of batteries. The instrument is elegant in appearance, 
and always ready for instant use.”—Student, January 1869. 
Price, with 2 magnets and changeable armatures, £6 tos. Ditto, with 4 
magnets in mahogany case, very powerful, £10 ros. Illustrated circular for 
stamped envelope. JOHN BROWNING, Optical and Physical Instrument 
Maker to Her Majesty’s Government, the Royal Society, the Royal Obser- 
vatory, &c., &c., rr, Minories, E., London. Established 100 years. 
BRAGG’S VEGETABLE CHARCOAL 
or PURE CARBON BISCUITS, a nutritious, pleasant, and healthful diet, 
which has produced great benefit and positive relief to thousands of sufferers 
from indigestion, bile, acidity, foul breath, dyspepsia, heartburn, worms, &c. 
There is medical testimony to its beneficial effect in these complaints.—Sold 
in tins, 1s., 2s., 4s., and 8s. each, by all chemists, and by the manufacturer, 
J. L. BRAGG, 14 (late 2), Wigmore Street, Cavendish Square 
OBSERVATORIES, EQUATORIAL TELESCOPES, ASTRONOMICAL CLOCKS, LEVELS, ETC. 
T. COOKE & SONS, 
Opticians to H.R.H. the late Prince Consort, the Royal Family, and Her Majesty's Home and Indian Governments, 
BUCKINGHAM WORKS, YORK. 
Illustrated Catalogues of Observatories, Equatorial and all other descriptions of Telescopes, Astronomical Clocks, Theodolites, Levels, 
Clinometers, Gold Band Aneroids, &c., manufactured by T, COOKE and SONS, may be had on application-to the Works. 
\ioies IE 
AA 
