July 26, 1 888] 



NATURE 



3" 



act c f disappearing. But when the organ of the species radiata 

 is carefully compared with the organ of the species batis and 

 cimtlaris, the evidence seems to point in an opposite direction, 

 and the view that the cups of Aaia radiata are in process of 

 being elaborated into more complex structures, such as already 

 exist in Kaia circulates, is apparently confirmed by the develop- 

 mental record. Were the electrical organ of Kaia radiata a 

 mere vestige of a larger structure which formerly existed, we 

 should expect to find the motor (electric) plate incomplete, or 

 only occupying a portion of the electric cup ; and the nerves pro- 

 ceeding to it, either few in number or undergoing degenerative 

 changes. But instead of this we have a relatively large bunch 

 of extremely well-developed nerves proceeding to the motor 

 plate, which is not only complete, but extends some distance 

 over the rim of the cup. Further, there is no indication of the 

 walls of the cup having ever consisted of extremely complex 

 \ lamellae, such as we have in Raia circularis. They consist of a 

 nearly solid mass of muscular tissue, scarcely to be distinguished 

 rom the unaltered adjacent muscular fibres. The electric cup 

 of Raia radiata may, in fact, when its structure alone is con- 

 | sidered, be said to be a muscular fibre which has been enlarged 

 at one end to support a greatly overgrown motor plate. But 

 I the development of the electric cups is even more suggesiive 

 I than their structure. Had the mu>cular fibres in Raia radiata 

 I assumed the fcrm of clubs before the young skate escaped from 

 I the egg capsule ; had the clubs been rapidly transformed into 

 electric cups ; and had the cups soon after reaching completion 

 ( begun to disappear, the evidence in favour of degeneration would 

 have been complete. But, as has been indicated, the conversion 

 of the muscular fibres into an electric organ is late in beginning, 

 ami the clubs having appeared, pass slowly through a long series 

 < f intermediate stages before they eventually assume the cup 

 form. Further, as has already been mentioned, in the largest 

 I specimens of Raia radiata examined no evidence was found of 

 retrogressive changes, either in the cup proper, or the numerous 

 nerves passing to its electric plate. Hence it may be inferred 

 that the electric organ of Raia radiata, notwithstanding its 

 apparent uselessness and its extremely small size, is in a state of 

 progressive development. 



Edinburgh. 



Royal Society, June 18. — In the report of this meeting 

 the title of a paper on the development and life-hi-tories of the 

 food and other fishes, communicated by Prof. W. C. Mcintosh 

 and Mr. E. E. Prince, was inadvertently omitted. 



July 2. —Prof. Chrystal, Vice-President, in the chair. — 

 Dr. Ramsay Traquair read a paper on fossil fishes from 

 the Pnmpherston oil-shale, and exhibited specimens. — Dr. 

 W. Peddie read a paper on the effects of electromotive force and 

 current-density on the total opposition (due to resistance of the 

 conductors, reverse electromotive force, &c. ) to the passage of 

 an electric current through a liquid. — Mr. George Brook de- 

 scribed a lucifer like crustacean larva from the West Coast, and 

 also communicated, in conjunction with Mr. W. E. Hoyle, a 

 paper on the metamorphosis of the British Euphansiidce. — Prof. 

 Haycraft and Dr. E. W. Carlier read a paper on morphological 

 changes which take place in blood during coagulation. — Prof. 

 Tait submitted a paper on Laplace's theory of the internal 

 pressure in liquids. 



July 9. — A special meeting was held, Sir Douglas Maclagan, 

 Vice-President, in the chair. — Dr. Berry Hart read a paper on 

 the mechanism of the separation of the placenta and membranes 

 during labour. — Dr. Woodhead communicated a paper, by Dr. 

 J. W. Martin, on the pathology of cystic ovary ; and also a 

 paper, by Mr. T. A. Helme, on histological observations on the 

 muscle, fibre, and connective tissue of the uterus during preg- 

 nancy and the puerperium. — Dr. T. G. Nasmyth read a paper 

 on the air in coal-mines. 



Paris. 



Academy of Sciences, July 16.— M. Janssen, President, in 

 the chair. — Experiments with a new hydraulic machine, by M. 

 Anatole de Caligny. This apparatus is of less simple structure 

 than the valved machine with oscillating tube already described 

 and exhibited by the inventor. But it has the advantage, under 

 certain conditions, of giving relatively better results. — On the 

 planet Mars, by M. Perrotin. These remarks are made in con- 

 nection with the four sketches referred to in a previous com- 

 munication, which are here reproduced, and which give the 

 appearance of the planet on May 8, 1888, June 12, 1888, May 



21-22, 1886, and June 4, 1888. The two first show the new canal 

 A and that of the north polar ice-cap, the second also giving the 

 smaller canal B seen for the first time on June 12. The fourth 

 shows four simple and three double canals, all clearly defined. 

 Two of the latter stretch from near the equator along the 

 meridians 330 and $° of Schiaparelli's chart to the vicinity of 

 the north polar ice-cap. The difference is very striking, 

 especially in the region of Libya, between the first and second 

 of this year, and the corresponding No. 3 for the year 1886. 

 — On the explanation of an experiment by Joule according to the 

 kinetic theory of gases, by M. Ladislas Natanson. The experi- 

 ment in question occurs in vol. i. p. 183 of Joule's " Scientific 

 Papers." From the considerations here advanced, M. Natanson 

 concludes that, so far from being opposed to the kineti c theory 

 of gases, this experiment might be regarded as a practical 

 confirmation of the law determining the distribution of molecular 

 velocities discovered by Clerk Maxwell, and generalized by 

 Boltzmann. — M. Natanson's paper was accompanied by a r.ote 

 from M. G. A. Hirn, who still maintains that not one of his nine 

 fundamental objections to the kinetic theory itself has yet been 

 answered, and consequently that this theory is already out of date. 

 — On the thermic conductibility of mercury above ioo° C, by M. 

 Alphonse Berget. In continuation of a previous note (Comptes 

 rendus, April 16, 1888), the author here gives the results of his 

 studies on the variation in the thermic conductibility of mercury 

 between ioo° and 300 C. For 1° he finds the variation in the 

 coefficient of thermic conductibility to be - 0*00045. — Measure- 

 ment of the velocities of etherification by means of electric 

 conductibilities, by M. Negreano. The author has already 

 shown that the velocity of etherification for a mixture with 

 equal equivalents of alcohol and acetic acid may be measured by 

 determining the electric resistance of the liquid by Lippmann's 

 electrometric method. In the present communication he extends 

 the same process to masses of alcoholic reagents or acetic acid 

 differing in the number of their equivalents. — Observations 

 respecting some recent communications from M. Sabatier on the 

 chlorhydrate of cupric chloride, and the chlorhydrate of cobalt 

 chloride, by M. Engel. While insisting on his admitted claim 

 to priority, the author points out that there are two distinct 

 chlorhydrates of the chloride of copper. He also shows that the 

 pale blue powdery precipitate observed by M. Sabatier is not a 

 chlorhydrate of chloride, but a hydrate of cobalt chloride — On 

 the elementary composition of crystallized strophan thine, by M. 

 Arnaud. This is an extract from Strophanthus Kombe, much 

 used by the Fans of West Equatorial Africa for poisoning their 

 spear- and arrow-heads. The formula is here shown to be 

 C 31 H 48 12 , its elementary composition thus showing it to be a 

 close homologue of the wabain (C^H^O^), the active 

 principle of the wabaio plant used for similar purposes by the 

 Somali people. — Influence of the temperature of fermentation on 

 the production of the higher alcohols, by M. L. Lindet. The 

 experiments here described seem to show that the yield of the 

 higher alcohols is little affected by varying the temperatures of 

 fermentation. — On Fascicularia radicans, C. Vig., a new type 

 of Anthozoa, by M. Viguier. This little specimen of an 

 Alcyonium was lately obtained during some dredgings in the port 

 of Algiers. From the description here given it appears to be 

 most closely related to the Paralcyonia, although sufficiently 

 distinct to form an independent group or sub-family of the 

 Fascicularia?. — M. A. d'Arsonval describes and illustrates a new 

 metal self-regulating stove, which is intended to maintain in- 

 variable temperatures by the exclusive use of gas and water. It 

 is specially adapted for physiological and microbiological 

 researches, and is constructed essentially on the same principle 

 as that submitted to the Academy on March 5, 1877. 



Berlin. 



Physical Society June 29. — Prof, von Helmholtz, President, 

 in the chair. — Dr. R. von Helmholtz exhibited a new form of 

 bolometer differing from that used by Langley. In Langley's 

 instrument the alterations of electrical resistance produced by 

 radiation are measured by introducing the exposed bolometer 

 into one arm of a Whealstone bridge a similar one protected 

 from the light being introduced into the second arm of the bridge, 

 while the other two arms contain a corresponding resistance. In 

 the new bolometer as constructed by Siemens and Halske all 

 four arms of the bridge are composed of equal wires rolled up 

 into a coil and of these coils 1 and 3 are illuminated, while 

 2 and 4 are kept dark, and then coils 2 and 4 are 

 illuminated, and 1 and 3 kept dark. By this means a four- 



