66 



NATURE 



[May 2 1. 1903 



A CORRESPONDENT of the Ttmes, writing from St. Vincent 

 on April 22, gives some interesting particulars of the 

 Soufri^re eruption of that date. Soon after daylight, he 

 observed that inside of a quarter of an hour the enormous 

 umbrella-like steam-cloud spread out enormously. At this 

 time no noise was noticeable in the town. A little later, 

 violent explosions occurred at frequent intervals. It soon 

 became quite dark, but, following previous cases, every- 

 thing began to go in the direction of Barbados. Fine 

 metallic dust fell until next day, black and gritty, apparently 

 magnetite. Chateaubelair did not suffer this time except 

 for another deposit of sand and small stones. Georgetown 

 suffered much, and large stones fell throughout the Carib 

 country. 



Much discussion has recently taken place with reference 

 to the behaviour of the Weston galvanic cell as a standard 

 of electromotive force. The observed anomalies appear to 

 be dependent upon the behaviour of the particular concentra- 

 tion (14-3 per cent.) of the cadmium amalgam previously 

 recommended for the standard form of the instrument, and 

 are not connected with any change in the condition of the 

 cadmium sulphate which enters into the composition of the 

 cell. It seems to be now definitely established that with 

 less concentrated cadmium amalgams the Weston element 

 gives quite normal and trustworthy indications. 



In the Sitzungsberichte der Berliner Akademie Profs. 

 Holborn and Austin describe some important experiments 

 on the loss of weight of the platinum metals when heated 

 to temperatures of 1000° to 1500° C. by means of an electric 

 current. In the case of platinum, rhodium and iridium 

 this loss of weight only takes place in an atmosphere con- 

 taining oxygen, and is probably due to a chemical change. 

 With palladium the phenomenon is independent of the 

 nature of the surrounding gas, but depends very consider- 

 ably on the pressure, the rate of loss of weight increasing 

 as the pressure of the gas decreases. The behaviour of 

 palladium agrees with the supposition that the loss of 

 weight is simply due to sublimation. 



We have received from Dr. Jansen a short summary of 

 the work already accomplished in the preparation of the 

 " Technolexicon, " to which we have referred on one or two 

 occasions recently. Up to the present assistance has been 

 received from 341 societies and more than 2000 industrial 

 establishments and individuals. Of the societies, 272 are 

 German, 42 English and American, and 27 French. 

 An analysis of existing dictionaries, catalogues, &c., has 

 given a list of something like one and a quarter million 

 words, and it is expected that a large number more will be 

 obtained from the note-books of collaborators, which will 

 be called in during 1904. It is not expected that the 

 dictionary will be ready for printing until the end of 1906. 



Prof. Ladislaus Natanson has published in the Journal 

 of Physical Chemistry for February a lecture delivered 

 before the Cracow Academy of Sciences on " Inertia 

 and Coercion." The author considers that the phenomena 

 of nature can be divided into two classes, those which bear 

 a character of permanence, and those which tend to subside. 

 Under the first category he places the motions considered in 

 the ideal systems of rational dynamics, and the equilibria of 

 classical thermodynamics. There are, however, other cases 

 in which the two classes of phenomena cannot be considered 

 separately ; these are studied in the subject of thermo- 

 kinetics. Equilibrium is only a limit to phenomena, and 

 to study what actually occurs in nature we must go on to 

 study the laws which preside over their progress. In cases 

 where a disturbance tends to subside, as in the diffusion 



NO. 175 1, VOL. 68] 



of gases, the conduction of heat, and the flow of electricity, 

 we find that the progress of the phenomenon is represented 

 quantitatively by the flux of a certain quantity per unit 

 time across unit surface. This flux depends in general on 

 what may be called the stimulus of the phenomenon. This 

 " stimulus " may give impetus to the flux, but it will in 

 every case be largely employed in overcoming " coercion," 

 a property which always tends to impede the flow, but does 

 not in general {e.g. in the case of diffusion of gases) destroy 

 it altogether. 



In the Contemporary Review for May, Mr. Frederick 

 Soddy, whose name is well-known as a co-worker with Prof. 

 E. Rutherford at the McGill University, Montreal, describes 

 what may be referred to as the Canadian view of radio- 

 activity. Briefly stated, this is to the effect that the radio- 

 active thorium X, which is contained in ordinary thorium, 

 and can be separated by precipitating the inactive thorium by 

 means of ammonia, is a first decomposition-product of the 

 unstable thorium atoms, that the radio-active emanations 

 which are transmitted by thorium X to neutral gases, such 

 as hydrogen and nitrogen, and which are condensed by 

 cooling to —130° C, represent a further stage in the 

 atomic degradation, and finally it is suggested that helium 

 — an invariable constituent of radio-active minerals — is 

 possibly the last and stable product of the shattered thorium 

 atoms. According to this view, which will not be received 

 without an effort by chemists trained to believe in the con- 

 servation of matter and the immutability of the elements, 

 the energy of radium is derived from the deflagration of a 

 minute and unweighable proportion of the almost explosive 

 radium atoms. 



In the Nineteenth Century, Mr. William Ackroyd, writing 

 on " Radium and its Position in Nature," directs attention 

 to the fact that radium not only has the highest atomic 

 weight, but probably, in accordance with a well-known law, 

 is also the rarest of the known elements. The close re- 

 semblance between Becquerel rays and X-rays is referred 

 to, and it is suggested that the production of the former 

 is analogous to the phosphorescence of calcium sulphide 

 after exposure to sunlight. The possibility that an atomic 

 bombardment may be the source of energy of radio-active 

 bodies is, however, inferred from a reversed phenomenon 

 observed by Prof. Graham Bell and Mr. Sumner Tainter, 

 in which solids, liquids and gases are made to emit a 

 musical sound under the influence of an intermittent beam 

 of light pulsating 500 or 600 times in a second. 



In a paper dealing with the infection-powers of ascospores 

 in the Erysiphaceae (Journal of Botany, May), Mr. E. S. 

 Salmon takes up a subject which has been almost un- 

 touched. It is known that conidial forms of apparently 

 the same species are restricted in their power of germin- 

 ating to definite and distinct host-plants, and thus there 

 are differentiated a number of so-called biologic forms. 

 Whether ascospores show a similar selective capacity for 

 infecting host-plants is the problem which Mr. E. S. 

 Salmon endeavours to elucidate. 



An article of considerable interest which appears in the 

 Transactions of the Royal Scottish Arboricultural Society 

 refers to the inception of the scheme for laying out tree 

 plantations on the gathering grounds of waterworks. On 

 the lands belonging to the Halifax Corporation, which took 

 the lead in this matter, ash, sycamore and alder have been 

 planted along with Scots pine and larch, but the intention 

 is to leave the hardwood only as a permanent crop. Other 

 papers which are of primary importance to foresters relate 

 to the larch and its diseases, thinnings in planted spruce, 

 and the injurious effect of smoke on trees. 



