March 12, 1896] 



NATURE 



453 



Wiedemann'' s Annalen der Physik tind Chetnie, No. 2. — 

 Methods of determining dielectric constants, by W. Nernst. 

 The author employs a bridge in which two branches are 

 always equal ; the third contains the dielectric trough, and 

 the fourth a variable resistance and a variable capacity in 

 parallel. Connecting two opposite terminals with . a high- 

 frequency induction coil, and the two others with a telephone, 

 the latter is only silent when the resistance and the capacity in 

 the fourth branch are equal to those of the dielectric in the 

 third. An attempt to verify this by comparison with the electro- 

 meter method was foiled by the uncertainty of the latter. — A 

 modification of the electrometer method, by J. F. Smale. This 

 is based upon the attraction of a needle immersed in the 

 dielectric by conductors kept at a constant potential. The con- 

 ductors are two semi-ellipses nearly surrounding the flat needle 

 of platinum, which is suspended by a quartz fibre. The deflec- 

 tion of the needle from its position of rest is proportional to the 

 dielectric constant of the medium. A comparison with Nernsl's 

 method gave practically identical results. — An apparatus for 

 varying self-induction, by Max Wien. This consists of a fixed 

 and a movable coil. The fixed coil is subdivided into four, 

 each of which can be placed in circuit, so that the self-induction 

 can be abruptly changed. The interval between each abrupt 

 change is filled up by moving the movable concentric coil about 

 its diameter, by means of an arm travelling over a graduated 

 circle. The range of the apparatus is very large, and self- 

 inductions from 5 >. lo-' to lo'" can be measured. — Refraction 

 and reflection of electric waves by water and alcohol, by 

 A. D. Cole. For waves 300 to 600 cm. long, water has 

 an index of refraction of 8'95, alcohol 5 "20. Calculated 

 by Fresnel's formula from the reflection of polarised rays, the 

 refractive indices for wave-lengths of 5 cm. come out as 8 8 for 

 water, and 3 "2 for alcohol ; so that alcohol shows a remarkably 

 higher refraction for long than for shorter waves. — Lowest 

 temperatures and the liquefaction of gases, by C. Linde. Air 

 is liquefied exclusively by the action of its own expansion, each 

 portion of the expanded air being conducted past the next ex- 

 panding proportion, and cooling it down to a lower temperature. 

 The apparatus is almost identical with that recently described 

 by Prof. Dewar, but the author claims priority. — The wave 

 siren, by Rudolph Kcinig. This paper contains the results of 

 a minute and careful investigation of the behaviour of the air 

 current in a wave-siren. The air is blown through a slit, which 

 is lengthened or shortened by the curved edge of a plate rotating 

 in front of it. Any tone is thus directly reproduced from its 

 wave-form. The air current remains sharply defined to a distance 

 of about I cm. from the slit, and the wave-plate need therefore 

 not be mounted very close to it. There is no accumulation of 

 air by the closed portions of the slit leading to irregularities in 

 the tone, and the vortex efiects at the edges are without any 

 influence upon the tone. The loudness of the sound produced 

 by a simple sine curve increases with the width of the slit, 

 reaching a maximum where the width is half the wave-length. 

 Most vowels can be correctly reproduced from their known 

 wave-forms. 



Bollettino della Societh Sismologica Ilaliana, vol. i., 1896, 

 No. 9. — Review of the principal eruptive phenomena in Sicily 

 and the adjoining islands during the four months, May-August, 

 1895, '^y S. Arcidiacono. — Notices of Italian earthquakes (July- 

 August, 1895), by M. Barratta, the more important being those 

 of the Comacchio earthquake of July 30, and part of those of 

 the Adriatic earthquake of August 8. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, January 30. — "On the Rhythmic Con- 

 tractility of the Spleen." By E. A. Schafer, F.R.S., and B. 

 Moore. 



The authors have investigated the rhythmic contractility of 

 the spleen, which was discovered by Roy ([ourn. Physiol., vol. 

 iii. ), and the influence of nerves, drugs, and animal extracts upon 

 it. For this purpose the changes in its volume have been studied 

 liy aid of a specially constructed plethysmograph, so arranged as 

 to afl'ord the least possible obstruction to the blood-vessels 

 entering and leaving the hilum. Under these circumstances, 

 ihe spleen exhibits evidence of responding immediately by 

 ilterations in volume to every alteration in blood pressure, 

 respiratory and cardiac, and ii fortiori to such greater changes as 



NO. 1376, VOL. 53] 



are produced by compression of the aorta (contrary to Roy). 

 This is even manifest when the organ is left connected with the 

 rest of the vascular system by one artery and vein only. The 

 conclusion which Roy arrived at, that the spleen is practically 

 cut off from the arterial system, and that its circulation is main- 

 tained by its own contractions, is thus shown to be incorrect. 



The rhythmic contractions are independent of the central 

 nervous system. 



They are excited to increased activity by intravenous injection 

 of certain drugs and animal extracts which act specifically upon 

 the organ. Indiflerent fluids, such as normal salt solution, pro- 

 duce in moderate quantity no such effects (contrary to Roy). 



Dyspnoe.i causes marked contraction of the spleen. This 

 contraction is of central origin, for after severance of all nerves 

 to the organ it is replaced by a passive dilatation, due to the 

 rise of general blood pressure, followed by an increase in extent 

 of the rhythmic contractions. Temporary cessation of the blood 

 flow through the organ also has the effect of increasing their 

 extent, probably because the splenic tissue is thereby deprived of 

 oxygen. 



The splanchnics contain not only nerve fibres which produce 

 contraction of the spleen, but also others which cause dilatation. 



There is no evidence that the vagi contain any centrifugal 

 fibres which influence the volume of the spleen (contrary to Roy). 

 Provided their inhibitory action upon the heart is neutralised by 

 atropine, even the strongest stimulation of the peripheral end of 

 either cut vagus produces no direct effect upon the spleen. 



There is evidence of the existence of numerous afferent 

 (sensory) fibres in the nerves supplying the spleen. 



Entomological Society, February 19. — Prof. Raphael 

 Meldola, F.R.S.. President, in 'the chair. — Dr. D. Sharp, 

 F. R.S. , exhibited preparations of Dytisciis latissiniiis and 

 Cybister roeselii, to show the so-called secondary wing, noticed 

 by Meinert. He stated that this structure is only a part of the 

 elytron, to which it is extensively attached, and that he con- 

 sidered that it corresponded with the angle at the base of the 

 wing seen in so many insects that fold their front wing against 

 the body. He could not consider that this structure afforded 

 any support to the view that the elytra of beetles correspond 

 with the tegulte of Hymenoptera rather than with the front 

 wings. He also exhibited specimens of Neuroptera, and 

 pointed out that this secondary wing agreed in position and 

 structure with a small lobe on the front wing of Raphidi.i. Mr. 

 McLachlan, Prof. Meldola, and Mr. Gahan made some remarks 

 on the subject. — Mr. C. G. Barrett exhibited, for Dr. H. Cj. 

 Knaggs, cells of Ketinia resinana formed of resin but lined 

 with wax. A portion of the cell had been removed and the 

 resin dissolved away with spirit, leaving a slight film of wax. 

 Mr. Tutt stated that a secretion of wax had been detected by 

 Dr. Chapman in Parnassitis apoUo. Prof. Meldola suggested that 

 as Dr. Knaggs had shown how to separate the resin from the 

 wax, it would be of interest to make a chemical investigation of 

 the latter, since a sufficient supply of this material could easily 

 be obtained. No insect wax, with the exception of that of the 

 bee, had been submitted to investigation by chemists. Mr. 

 Hampson and Mr. Blandford continued the discussion. — Mr. 

 Gahan exhibited drawings of the dor.sal segments of the abdo- 

 men of Dyscritina longisetosa, formerly described by Prof, 

 West wood in Trans. Ent. Soc, 1881, a specimen of which was 

 shown by Mr. E. E. Green at the last meeting of the Society. 

 He regretted that no drawing, showing the ventral service, had 

 yet been prepared. — Mr. B. A. Bower exhibited specimens of 

 Argyresthia ati/iorieila, Bankes, taken in Kent, in June 1894, a 

 recent addition to British Lepidoptera. — .Mr. Green read notes on 

 the habits of the Indian ant, Qicophylla smaragdina, Fabr. He 

 said he believed that at some previous meeting of the Society, 

 Mr. Ridley, of the Singapore Museum, made some remarks on this 

 ant and its supposed habit of using its own larvye as web-spinners 

 in the formation of its nest, but he had not been able to find 

 anything on the subject in the Proceedings. Mr. Green stated that 

 he was now able to produce corroborative evidence from an inde- 

 pendent source. The facts were noted by his friend Mr. W. D. 

 Holland, of Balangoda, Ceylon, a most careful observer. Mr. 

 Green exhibited the specimens referred to by Mr. Holland, and 

 pointed out that the larva; were still tightly grasped by the jaws 

 of the ants, and he thought it probable that other web-spinning 

 ants utilised their larvae in the same way. Mr. Hampson said 

 he could confirm this statement.— Mr. G, F. Scott-Elliot read a 

 paper entitled " Notes on Flower- Haunting Diptera." The 

 author pointed out that some of the higher types of Diptera 



