!92 



NATURE 



[August 20, 1891 



liarly useful as backgrounds for the bright prominence lines, and 

 allows the u-;e of a wide slit. Working with a tangential slit, 

 Prof. Hale has obtained excellent photographs of reversals of 

 H and K. The former line is found to be double, the com- 

 panion being about I '5 tenth-metres less refrangible, and pos- 

 sibly coincident with a line of hydrogen at A 3970'25. The 

 photographs also show three bright lines, which appear to be 

 coincident with the lines a, ;8, and 7 of the hydrogen series. 

 The first of these is seen as a double line, the components of 

 which are separated by a fraction of a tenth-metre. 



It is highly probable that a large number of prominences 

 cannot be made out by the ordinary method of observing the 

 C line. These invisible or " white " prominences must therefore 

 be detected photographically. But as it would be an extremely 

 troublesome process to take a set of photographs with the slit 

 tangential to various points on the limb, and as prominences 

 having a considerable elevation could not be easily photographed 

 by this method, another arrangement has been devised which 

 nullifies these objections, and allows eye observations of C to 

 be made while the exposure to the H and K region is going on. 

 Certainly, if Prof. Hale should be able to do for invisible pro- 

 minences what has been done at Palermo for those visually 

 observable, our knowledge of the relation between the two 

 classes of phenomena and their connection with sun-spots 

 would be considerably extended. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



The following is the list of candidates successful in the compe- 

 tition for the Whit worth Scholarships and Exhibitions, 1891 : — 

 (i) Scholarships, £\2^z. year each (tenable for three years) : — 

 Robert W. Weekes, electrical engineer ; William G. Rennie, 

 engineering student ; Thomas G. Jones, engineer ; William H. 

 Pretty, mechariical engineer. (2) Exhibitions, ^50 a year each 

 (tenable for one year): — Julian J. King-Salter, student; Louis 

 Martineau, engineer ; Harold R. Cullen, engineer apprentice ; 

 Frederick Hossack, mechanical engineer ; William A. Lelean, 

 engineering draughtsman ; William F. Nixon, engineer ; John 

 Chambers, draughtsman ; Joseph W. Kershaw, student ; Charles 

 H. Gadsby, engineer's draughtsman ; Frederick Charles Lea, 

 apprentice millwright ; George Thomas White, mechanic ; 

 Joseph H. Gibson, marine engineer ; Henry Fowler, engineer 

 apprentice ; Arthur E. Malpas, engine fitter apprentice ; James 

 Hall, student ; Walter E. Lilly, engineer ; Charles Jefcoat, Jun., 

 turner ; Percy V. Vernon, fitter ; George E. Armstrong, engi- 

 neer student ; Martin DeVille, draughtsman ; Richard H. 

 Cabena, marine engineer's draughtsman ; Frederick Dodridge, 

 engine fitter ; Alfred J. Ward, mechanical engineer ; William 

 E. Tubbs, coachmaker ; Alexander Norwell, mechanical engi- 

 neer ; Richard Baxendale, draughtsman ; Walter Amor, fitter ; 

 Thomas Bouts, engineer ; Alfred Meyer, draughtsman ; John 

 W. Anderson, draughtsman. 



The list of successful candidates for Royal Exhibitions, National 

 Scholarships, and Free Studentships, 1891, is as follows : — 

 National Scholarship for Biological Subjects — George S. West, 

 student. National Scholarship for Chemistry and Physics — 

 James Bruce, student. National Scholarship for Mechanics — 

 Sydney G. Starling, student. National Scholarships — Charles 

 H. Sidebotham, student ; Bernard E. Spencer, student ; James 

 H. Smith, pattern maker ; John Ball, engineer ; Charles Harold 

 Robinson, tobacconist ; George W. Fearnley, student ; Charles 

 J. Gray, student ; Francis Carroll, student ; Ralph M. Archer, 

 teacher ; Harry Verney, fitter ; James Thompson, teacher. 

 Royal Exhibitions— Hubert Cartwright, student ; Walter H, 

 Watson, laboratory assistant ; Sidney G. Horsley, student ; 

 Charlie R. Cross, student ; Watson Crossley, cotton weaver ; 

 Samuel D. Crothers, farmer ; Peter Pinkerton, student. Free 

 Studentships— David Baxandall, student; Herbert C. Robin- 

 son, student ; William G. Freeman, student ; Charles H. 

 Gadsby, engineer's draughtsman ; Stephen Pace, none ; William 

 H. Dolman, teacher. 



SOCIETIES AND ACADEMIES. 

 Paris. 

 Academy of Sciences, August 10.— M. Duchartre in the 

 chair. — Artificial production of a micaceous trachyte, by MM. 



F. Fouque and Michel Levy, This trachyte was obtained by 

 the action of water under pressure on a glass resulting from the 

 fusion of Vire granite, and at a bright red heat. The rock was 

 homogeneous, and its sections exhibited beautiful octahedral 

 crystals of a variety of spinel in connection with orthoclase and 

 black mica. — Note on an experiment on ostriculture that has been 

 carried out in the fish-pond of the RoscofT Laboratory, by M. H. 

 de Lacaze-Duthiers. — Physiological research on carbon mon- 

 oxide in a medium containing it in the proportion of one ten- 

 thousandth, by M. N. Grehant. After passing a mixture 

 containing a ten-thousandth part of carbon monoxide through 

 blood for half an hour, it was found that the respiratory capacity 

 of the blood was diminished from 237 to 230 per cent. The 

 difference (07) represents the amount of oxygen replaced by 

 carbon monoxide. When the gas was passed through under a 

 pressure of five atmospheres, it was found that the respiratory 

 capacity had diminished from 237 to 17-2. This result may be 

 applied to the detection of small quantities of carbon monoxide 

 in confined air, and it also indicates that it is not only the per- 

 centage proportion of the gas which must be considered in 

 questions relating to the absorption of it by haemoglobin, for this 

 remained the same in both experiments, viz. To^^irth. — On the 

 refraction and dispersion of crystallized chlorate of soda, by M. 

 Frantz Dussaud. The author has measured with five different 

 instruments the refractive index of chlorate of soda at tempera- 

 tures between 0° and 30°, and for twelve lines in the spectrum. 

 For the sodium line (D) and a temperature of 20° the value 

 obtained is 1-51510. The result for a is 1-50197, and for Cd (18) 

 1-58500. — On the habits of Gobius minutus, by M. Frederic 

 Guitel.— On the pathological types of the curve of muscular 

 action, by M. Maurice Mendelssohn. — On the preventive in- 

 oculations of yellow fever, by M. Domingos Freire. The author 

 has inoculated io,88i persons with cultures of Micrococcus 

 amaril. The mortality of those so vaccinated was 0-4 per cent., 

 although the patients lived in districts infected with yellow fever, 

 whilst the death-rate of the uninoculated during the same period 

 was from 30 to 40 per cent. These results have led the Govern- 

 ment of the Brazilian States to found an institute for the culture 

 of the virus of yellow fever and other infectious diseases, and to 

 appoint M. Freire the director.— On a new incandescent light, 

 by M. Bay. 



CONTENTS. PAGE 



The Congress of Hygiene 361 



Letters to the Editor : — 



Aerial Roots of the Mangrove. — Alfred W. 



Bennett 370 



The Tasman Sea. — Prof. A. Liversidge, F.R.S. . 371 

 Reduplication of Seasonal Growth. — Dr. A. Irving . 371 



Rain-gauges. — Thos. Fletcher 371 



The British Association :— 



Inaugural Address by William Huggins, Esq., 

 D.C.L. (Oxon,), LL.D. (Cantab., Edin., et 

 Dubl.), Ph.D. (Lugd. Bat.), F.R.S., F.R.A.S., 

 Hon. F.R.S.E., &c., Correspondant de I'lnstitut 



de France, President 372 



Section A (Mathematics and Physics). — Opening 

 Address by Prof. Oliver J. Lodge, D.Sc, 

 LL.D., F.R.S., President of the Section .... 382 



The Late Prof. Martin Duncan, F.R.S 387 



Notes 388 



Our Astronomical Column : — 



Periodic Variations in the Latitude of Solar Promin- 

 ences. {With Diagram.) 391 



Photography of Solar Prominences and their Spectra 391 



University and Educational Intelligence 392 



Societies and Academies 392 



NO. 1 138, VOL. 44] 



