554 



NA TURE 



[October 3, 1901 



phosphate of soda, which on analysis was found to contain 

 arsenic equal to ,y62 grains of arsenious oxide per pound. The 

 samples examined for the India Ofifice were of the usual wide 

 range. Gold-leaf is required to contain not less than 97 per 

 cent, of pure gold, but in one instance a sample contained 

 5 per cent, of silver and only gr per cent, of gold ; type-metal 

 is to consist of 65 parts of lead, 3° parts of antimony 

 and 5 parts of tin, and yet in eight samples received together, 

 the lead varied between 65 and 82 per cent., the antimony 

 between 15 and 29 and the tin between 0'6 and 5-5 per cent.; 

 antimony is required to contain less than 3 per cent, of 

 impurities, but of five samples two contained 576 and 4'I5 per 

 cent, of impurity respectively. The functions of the Govern- 

 ment Laboratory are evidently exercised over a wide field, and 

 national interests are promoted by such analytical work as is 

 carried on under Dr. Thorpe's direction. 



L\ Syiiions's Meteorological Magazine for September, Dr. 

 H. R. Mill, who accompanied the Antarctic exploring vessel 

 Discovery as far as Madeira, gives some details of the arrange- 

 ments for taking observations. During the voyage out meteor- 

 ological observations will be made every two hours, and these 

 will be kept up subsequently to supplement those made at the 

 land station. For the ordinary routine observations a form of 

 Stevenson's Screen is erected in a position where a current of 

 air will be blowing, when the vessel is under way. Rainfall 

 observations are to be attempted by means of a marine rain- 

 gauge and evaporator on Dr. Black's pattern. The position 

 presented much difficulty ; the method finally adopted was to 

 place the gauge on the weather side, shifting it whenever the 

 ship changes her tack, while the evaporator occupies a position 

 on the lee side. The whole of the meteorological work on 

 board is under the charge of the first officer. Lieutenant C. 

 Royds. It is intended to make special observations in the 

 Antarctic regions on the conditions of the upper atmosphere, 

 and for this purpose a captive balloon and kites are provided. 

 \ Dines' pressure anemometer will be erected at the land 

 station. The oceanographical observations to be made during 

 the voyage will be under the charge of Lieutenant E. H. 

 Shackleton, while Lieutenant M. Barne will take charge of the 

 deep-sea soundings after leaving Melbourne. 



A REM.\RKABLY simple astatic galvanometer is described by 

 M. G. Lippmann in the Journal de Physique for .\ugust. It 

 consists essentially of a fixed coil, or in practice two coils, and 

 a needle suspended in such a way as to be capable of displace- 

 ment parallel to itself. The needle is placed with its axis 

 coinciding with that of the coils, and pointing in the plane of 

 the magnetic meridian. It is suspended by a thread from one 

 arm of a torsion balance. Now the earth's magnetism has no 

 tendency to produce displacements of pure translation in a 

 magnetised needle, and since it is these displacements which 

 alone are observed, it follows that the earth exerts no force in 

 opposition to that produced by the current in the coil ; the 

 apparatus is therefore perfectly astatic. 



.■Xn interesting phenomenon recently described in connection 

 with the theory of sound forms the subject of a paper by Mr. 

 Bergen Davis in the Physical Review for June. The property 

 in question is that if a small cylinder, closed at one end and 

 open at the other, is placed in a stationary sound-wave, it will 

 not only arrange itself perpendicular to the wave, but will also 

 move across it in the direction of its axis. By arranging four 

 such cylinders on a rotating mill, like the cups on an anemo- 

 meter, and placing this mill with its axis of rotation perpendicular 

 to the wave front, it was found that on sounding the organ pipe 

 producing the waves, the cylinders rotated with a high velocity, 

 except when placed at the nodes. The phenomenon is readily 

 NO. 1666, VOL. 64] 



explained as a consequence of Bernouilli's well-known relation 

 between the pressure, density and velocity of a fluid. 



Maxwell's theory, which attributes electric and magnetic 

 phenomena to tensions and pressures in the medium that 

 forms the seat of electric and magnetic energy, has long been a 

 subject for criticism. In the Nuovo Cimento, 5, ii. , Signor 

 Luigi Giuganino now advances certain considerations arising 

 from a mathematical investigation of the tensions in the interior 

 of a fluid polarised magnetically or dielectrically. The author 

 finds, among other results, that if the polarised body is com- 

 pressible and behaves like a fluid body, and only carries induced 

 charges, it is impossible to find a system of elastic stresses 

 equivalent to the given polarisation. If, however, the polarised' 

 body is considered to be an imperfect fluid, either there exist an 

 infinite number of systems of tensions and pressures equivalent 

 to the polarisation, or no such system exists. The expression 

 for these tensions and pressures does not, however, reduce to 

 Maxwell's and Helmholtz's formula. Signor Giuganino further 

 advances the view that the elastic constant of the fluid when 

 polarised assumes different values along and perpendicular to 

 the lines of force, and that herein lies the explanation of Kerr's 

 phenomenon. 



In the last Bollcttino of the Italian Seismological Society, 

 Prof. Grablovitz describes a simple and inexpensive form of 

 recording tide-gauge, the total cost of which he estimates at less 

 than 7/. \os. The movements recorded are those of a spiral 

 spring the length of which changes with the varying amount of 

 immersion of a cylinder suspended from it. 



In continuation of his previous reports, Mr. S. Arcidiacono 

 describes the principal eruptive phenomena which occurred in 

 Sicily and the adjacent islands during the year 1900 (Boll, della 

 Soc. Sismol. Ital. vol. vii. 1900, pp. 82-91). After the great 

 explosion in the central crater of Etna on July 19, 1899, and the 

 short eruptive period which succeeded it, that volcano remained 

 in a state of almost uninterrupted calm. Stromboli continued 

 in its usual condition of slight activity, varied by a few stronger 

 outbursts, especially in the early part of October. The solfa- 

 taric phase of Vulcano and the absolute calm of the Salsa di 

 Paterno underwent no change throughout the year. 



A CATALOGUE of the marine invertebrata of Eastern Canada, 

 by Dr. J. F. Whiteaves, has also been published by the 

 Geological Survey of Canada (1901). It consists of a systematic 

 list of all the species described from the Bay of Fundy, the 

 Atlantic coast of Nova Scotia, the Gulf and mouth of the River 

 St. Lawrence, as far north as the Strait of Belle Isle. The 

 localities at which some of the species are found fossil in the 

 Pleistocene deposits are also briefly indicated. 



Dr. G. A. F. MoLENGRAAFF, who was formerly State 

 Geologist to the South African Republic, has written an excel- 

 lent account of the geology of the Transvaal Colony, which has- 

 been published by the Geological Society of France (Bullelin, 

 4e serie, vol. i. 1901). It is accompanied by a colour-printed 

 map, and many pictorial views and sections. * 



A SIXTH edition of Mr. Whitaker's useful "Guide to the 

 Geology of London" has just been issued by the Geological 

 Survey. The first edition was published in 1875, and in the 

 present edition the work has grown to the extent of thirty pages, 

 partly owing to an increased number of illustrations, including 

 fossils, flint-implements, and sections of strata. The work has 

 been brought thoroughly up to date, and the price remains one 

 shilling. 



We have received from the Geological Survey of Canada the 

 Annual Report for the year l8gS (Ottawa, 1901). This includes 

 the Summary Report, and also a report on the mineral statistics. 



