122 



NATURE 



[October i, 19 14 



It was in 1871 that Lord Rayleigh first proposed a 

 theory to account for the scattering of light by small 

 particles, and in particular to explain the blue sky. 

 Various other papers have followed on the subject by 

 different writers. In the BtUletin de I'Acaddmie des 

 Sciences de Cracovie, Dr. Ladislas Natanson, in a 

 paper communicated last January, discusses the 

 problem on lines consistent with the modern electron 

 theories. The author first considers the effect of a 

 vibrating electron in the presence of a train of electro- 

 magnetic waves, using Planck's formula. An expres- 

 sion is found for the energy of the scattered wave ; 

 this is found to vanish in the direction of propagation 

 and to be a maximum in the equatorial plane. The 

 electric and magnetic energies are not in general 

 equal. When it is sought to deal with a medium 

 containing a large number of such vibrators the 

 problem cannot be solved without making certain 

 assumptions which can only be regarded as a first 

 approximation. With these the author obtains 

 formulae for the coefficient of transmission of the 

 medium and its dependence on the wave-length. 



The scientific study of the acoustical properties of 

 public buildings is a subject the neglect of which 

 may involve losses of thousands of pounds. The 

 large hall presented to the University College of North 

 Wales by Sir John Prichard-Jones possesses an echo 

 quite equalling the famous one of the baptistery at 

 Pisa, but this feature renders it useless for many 

 purposes for which it would otherwise be in requisi- 

 tion. Mr. F. R. Watson's article on the acoustics of 

 auditoriums in the University of Illinois Bulletin xi., 

 29 (Bulletin No. 7, Engineering Experiment Station ; 

 London : Chapman and Hall, 1914, price 20 cents) is 

 a welcome contribution to this study. The investiga- 

 tion refers primarily to the auditorium of the Illinois 

 University, which has formed the subject of the author's 

 researches since 1908, one year having been spent by 

 him in general studv abroad. Mr. Watson discusses 

 Sabine's formulae for the effect of absorption on rever- 

 beration, and arrives at the following general infer- 

 ences : — Wires have but little effect ; air currents due 

 to ventilation may even be worse than useless. In his 

 survey of the building in question he has determined 

 both experimentally and theoretically the paths of the 

 sound waves reflected from the various surfaces, plane 

 and curved, of the building, and the formation of foci ; 

 and a remedy has been proposed involving the placing 

 of curtains in positions determined from these observa- 

 tions. The sources of sound employed in these experi- 

 ments include a ticking watch, an alternating arc 

 current in presence of a concave mirror, and a directed 

 source ingeniously obtained with the aid of a metro- 

 nome. But the Illinois auditorium with its concave 

 walls and curved roofs is so different from the 

 rectangular Prichard-Jones Hall at Bangor, that an 

 investigation which is sufficient for one building will 

 scarcely be likely to explain, except very partially, the 

 defects of the other. 



It is remarkable that no extended use has ever been 



made of a phonographic attachment to a telephone for 



recording spoken messages. The Poulsen tele- 



graphone in which the received currents produced a 



NO. 2344, VOL. 94] 



record by magnetising a steel wire or tape was un- 

 doubtedly a scientific success, and perfect speech re- 

 production could be obtained by its means, but it 

 never made a position for itself as a commercial instru- 

 ment. The reason for this may have been that the 

 telegraphone had to be electrically connected to the 

 line, and there were possibly some technical or ad- 

 ministrative objections to such an addition to a sub- 

 scriber's instrument. From an article in the Scientific 

 American it appears that a new Edison instrument, 

 called the " telescribe," has recently been evolved in 

 which the arrangements are more akin to the Edison 

 wax phonograph. The ordinary telephone receiver of 

 the subscriber's instrument is placed against a very 

 sensitive transmitter, in a local circuit with a battery g 

 and another " special " telephone receiver, and the M 

 latter is arranged to emit its sound waves against the 

 ordinary sound-recording diaphragm of a phonograph. 

 The instruments of this local circuit must apparently 

 be designed so as to act as a telephone relay and 

 increase the amplitude of the vibrations sufficiently 

 to cut the wax phonograph cylinder. A second receiver 

 on the subscriber's set enables him to listen to the 

 message, and even to contribute his share of the 

 conversation, so that the whole or part of it may be 

 recorded as he desires. This is certainly an ideal 

 arrangement if it gives satisfactory records without 

 impairing the clearness of the articulation by the 

 relaying process. 



The value of the scientific exploration of the agri- 

 cultural products of India is well illustrated in a paper 

 by Mr. C. Somers Taylor, agricultural chemist to the 

 Government of the province of Behar and Orissa, 

 contributed to vol. ix., part iii., of the official Agri- 

 cultural Journal of India. Discussing the problem of 

 the varying amount of sugar obtainable from cane 

 juice, he remarks that at one time this was thought 

 to be dependent on the presence of glucose. This 

 theory has now been proved to be unsound by the great 

 Dutch sugar chemist, Geerligs. On the other hand, 

 the same authority — and his conclusions are verified 

 by Indian research — shows that a high percentage of 

 potash is, as a rule, accompanied by a low quotient 

 of purity, a low saccharine content, and a high glucose 

 content when the cane is ripe. The question of potash 

 content is carefully examined by Mr. Somers Taylor 

 in this paper, and he concludes that work on the 

 potash content of cane juice is likely to be of great 

 value in the examination of different varieties of canes, 

 and in consequence the official chemists propose to 

 take up this study more fully in the near future. 



The Institute of Chemistry has issued a " History 

 of the Institute, 1877-1914," compiled, by direction of 

 ' the council, by Mr. Richard B. Pilcher, the registrar 

 and secretary. The institute had its origin in a meet- 

 ing held on April 27, 1876, to discuss the necessity for 

 organisation among chemists for the purpose of en- 

 hancing their professional status; at this meeting 

 Prof, (later Sir) Frederick Abel presided. A com- 

 mittee was appointed to confer with the Chemical 

 Society with regard to a scheme for establishing an 

 organisation of professional chemists, and ultimately 



