288 



NATURE 



[July 21, 1898 



in the urine, are shown to be susceptible of another explanation, 

 — Presence of chlorophyll in a nostock cultivated entirely in the 

 •dark, by MM. A. ifetard and Bouilhac. The green colouring 

 matter, previously noticed by M. Bouilhac, is here proved to be 

 ordinary chlorophyll. — On a product of decomposition of 

 albumen, by M. J. M. Albahary. In an attempt to prepare an 

 iodine derivative of albumen, a new acid was obtained, oval- 

 buminic acid, forming a definite, crystallised sodium salt, and 

 also a gold salt. The molecular weight of the acid determined 

 by means of the latter was 1670.— Action of the sorbose bacteria 

 upon xylose, by M. Gabriel Bertrand. The bacterium exerts 

 an oxidising action, an acid, xylonic acid, being formed in small 

 <}uantity. — New biological abservationsupon the life in colonies 

 of the fixed tunicates, by M. Antoine Pizon.— Alkaline reaction 

 of the chambers and galleries of ants' nests. Duration of life 

 of decapitated ants, by M. Charles Janet. — Improvement of the 

 wild carrot, by grafting it on the cultivated carrot, by M.Lucien 

 Daniel. — Results of the ascents of three experimental balloons 

 at Trappes, on June 8, by M. L. Teisserenc de Bort. The 

 height attained was 13,000 metres, the lowest temperature 

 -59°C. — On a means of avoiding collisions at sea by means 

 of electromagnetic waves, by MM. A. Berget and L. Decombe. 

 — On stereoscopic vision in kinematography, by M. Aug. 

 Rateau. 



Amsterdam. 



Royal Academy of Sciences, May 28. — Prof, van de 

 Sande Bakhuyzen in the chair. — Prof. Schoute, on cyclographic 

 Tepresentation in space of Joachimthal's circles. — Prof. Haga, 

 -on maxima and minima of apparent brightness, resulting from 

 optical illusion. When in a plane on which the eye is fixed, 

 -two zones of mutually different, but each in itself of uniform (or 

 slowly varying) intensity of light are connected by a zone the 

 Intensity of light of which gradually decreases from that of the 

 .lighter to that of the darker zone, then the transition zone 

 seems to be separated from the brighter one by a still brighter 

 ;!ine and from the darker one by a still darker line. This 

 optical illusion, which occurs under very different circumstances, 

 and the peculiarities and possible explanation of which were 

 briefly indicated by the author, is important: (i) because it has 

 already often {e.g. in the case of X-shadow figures) made 

 investigators imagine that they observed diffraction or other 

 important lines ; (2) because it is not impossible that, for the 

 above reason, the indistinctness of the edge of a dark or a light 

 4ine may give, or have given rise to the observation of an 

 apparent doubling of such a line ; (3) because it may lead to an 

 ^incorrect estimation as to the place of the maxima and minima 

 in systems of lines, in which the intensity of light is not sym- 

 metrically distributed with respect to the middle of those 

 lines. — Prof. Beyerinck, on the relation of obligatous anaero- 

 t>ics to free oxygen. The moving bacteria present in great 

 numbers in preparations for the microscope, which allow the 

 air to enter at the edge of the cover-glass, arrange themselves 

 •an special figures according to their greater or smaller predilec- 

 tion for oxygen. The author has called them "figures of 

 respiration." Formerly he thought that three types might be 

 "distinguished: the "aerobic type," represented by those bac- 

 teria which seek the highest tension of the dissolved oxygen ; 

 the "spirillous type," corresponding to a medium; and the 

 * ' anaerobic type, ' ' corresponding to a minimum tension. Further 

 ■researches have shown that the anaerobic type, characterised 

 foy the accumulation of anaerobic bacteria at the place where 

 the oxygen tension is smallest — generally the centre of the 

 drop— rdoes not exist as a special case, and is only observed 

 -when the quantity of oxygen that enters, exceeds a certain 

 -minimum, and that at this minimum or below it all observed 

 .anaerobics arrange themselves into the figure of the " spirillous 

 type," i.e. they do not seek the smallest tension, but a 

 medium one, like the spirilli themselves. Consequently not 

 -three, but only two types exist, which may be termed aerophily 

 .and micro-aerophily. It can be shown that what has been said 

 about the mobility holds good for the growth of some, possibly 

 of all anaerobics, so that it is not absolute absence of oxygen 

 that is most beneficial for their growth. The experiment is 

 imade by sowing a very great number of non-aerated germs of 

 anaerobics together with a very great number of oxygen- 

 absorbing aerobics in a solid culture mass contained in a glass 

 tube, allowing diluted air to enter at only one end. A level of 

 imaximum growth of the anaerobics may then be observed, not 

 •deep down, where oxygen is quite absent, but at some distance 

 £rom the surface, where the tension is most favourable for them, 



NO. 1499, VOL. 58] 



which clearly shows that anaerobics are micro-aerobics also in 

 relation to growth. The anaerobic material, used for the ex- 

 periment, must be taken from cultures, long continued with 

 the exclusion of oxygen, which enables them to grow deep 

 down in the tube. It is probable that the possibility of their 

 aerobiosis depends on this very oxygen charge quite in the same 

 way as is the case with alcohol yeast. In conclusion all living 

 organisms, examined up to the present moment, are aerophilous 

 or micro-aerophilous with respect to mobility as well as to 

 growth. — Mr. Hamburger on the influence of salt solutions on 

 the volume of animal cells, being at the same time a contribu- 

 tion to the knowledge of their structure. — Mr. P. Zeeman pre- 

 sented a paper on an instance of asymmetry in the change of 

 the spectral lines of iron, radiating in a magnetic field. — Prof. 

 Kamerlingh Onnes presented, on behalf of Mr. E. van Ever- 

 dingen, jun., a communication entitled " Hall's effect in electro- 

 lytes." A formula for this effect in the case of a partially 

 dissociated electrolyte is deduced. By means of the simpler 

 formula for the effect in a completely dissociated solution, the 

 numerical value of the rotation of the equipotential lines in a 

 special case is calculated and compared with the result of 

 Bagard's experiments in the same case. The theoretical value 

 proves to be 10* times smaller than the observed value. The 

 author concludes that the difference of potential, observed by 

 Bagard, is due to disturbances, already indicated by Chiavassi 

 and others. 



CONTENTS. PAGE 



Technical Mycology 265 



Partial Differential Equations. By G. B. M. ... 266 

 Our Book Shelf:— 



Chaney : " Our Weights and Measures" 268 



Kaiserling : " Practicum der Wissenschaftlichen 



Photographic " 268 



Robinson : ' ' Principles of Mechanism " 268 



Ricci : " Introduzione alio Studio dei Silicati " . . . 268 

 Coles : " The Blood ; how to examine and diagnose its 



Diseases."— F. W. T 269 



Thornton : ' ' Notes on Volumetric Analysis " . . . . 269 

 Tristram : "A First Year's Course of Practical 



Physics, adapted for Beginners and Junior Students" 269 

 B. L. L. : " The Doctrine of Energy : a Theory of 



Reality" 269 



Letters to the Editor :— 



Solfatara Gases.— Prof, R. Nasini, F, Anderlini, 



and R. Salvadori 269 



"the Spectrum of Metargon. — Prof. Arthur 



Schuster, F.R.S 269 



Liquid Hydrogen. — Prof. James Dewar, F,R,S, , 270 

 Summer and Winter in Relation to the Sunspot Cycle. 



— A. B. M 270 



Rotifers in Lake Bassenthwaite.— W. T, Caiman . 271 

 The Story of the Smithsonian Institution. By 



H. R 271 



Spider and Pitcher-Plant. By R. I. Pocock ... 274 



Ferdinand Cohn. By Prof, J, B. Farmer 275 



Notes 275 



Our Astronomical Column : — 



Comet Perrine (June 14) 280 



A New Form of Grating Spectroscope 280 



Structure of the H and K Lines 280 



Blurring Aberration in the Telescope 280 



The Life-History of the Salmon 280 



The Stramberg Corals. By Dr. J. W. Gregory . . 282 

 University Education. By Dr. Michael Foster, 



Sec.R.S 283 



University and Educational Intelligence 285 



Scientific Serials 285 



Societies and Academies. {Illustrated.) 286 



