HA RD WICKE ' S SCIENCE- G O SSIP. 



Ichthyology ; wherever the name of Agassiz has been men- 

 tioned in connection with nomenclature or observations, his 

 "Recherches sur les Poissons fossiles " (Neuchatel, 1833-41) 

 may be consulted ; this treatise forms the basis of all subse- 

 quent research. 



Besides those in Agassiz' " Rech. Poiss. Foss.," good figures 

 and descriptions of the teeth of fossil Carchariidas, Lammidas, and 

 Notanidae, will be found in the Journ. Acad. Nat. Sci., Phila- 

 delphia, 1848-9 R. W. Gibbe's " Monograph of the Fossil 

 Squalidae of the United States," Parts 1., II.): and an elabor- 

 ate " Studi Comparativi sui Pessi Fossili coi Viventi dei Generi 

 Carcliarodon, Oxyrhina, e Galeocerdo," by R. Lawley, was 

 published at Pisa, four years ago. 



A new species of Carcluirodon (C. longidens, Pillet), from beds 

 in Haute- Savoie, supposed to be equivalent to the Maestricht 

 Chalk, was described and figured in the Mem. Acad. Sci. 

 Savoie, [3], ix., 1883, p. 277. 



Since our remarks on Psephodus, Dr. Traquair has published 

 an important contribution to the subject, noticed in the present 

 volume of Science-Gossip, p. 193 ; and we also ought to men- 

 tion particularly the valuable - * Illustrated Guide to the Fish, 

 Amphibian, Reptilian, &c, Remains of the Northumberland 

 Carboniferous Strata," by M. T. P. Barkas, F.G.S. The latter 

 appeared in 1873 (partly reprinted from the " Colliery Guar- 

 dian," 1871), and was followed by several articles from the pen 

 of Dr. W. J. Barkas in the " Monthly Review of Dental Sur- 

 gery " for 1874-76— an unfortunately inaccessible series, said to 

 contain much information regarding the microscopical structure 

 of the teeth of Coal Measure fishes. Carboniferous Selachians 

 likewise form the subject of a new volume (1883) of the Geol. 

 Survey of Illinois Reports, in which Messrs. St. John and 

 Worthen enter into a detailed study of the Cochliodontidas and 

 Psammodontidae. 



GOSSIP ON CURRENT TOPICS. 

 By W. Mattieu Williams, F.R.A.S., F.C.S. 



SCIENCE IN JAPAN.— Those who imagine that 

 the recent awakening and progress of Japan is 

 merely a superficial imitation of external Western 

 customs should study the records of the Scientific 

 Societies of that country. Important researches are 

 continually recorded. I have already referred, both 

 in this and the "Gentleman's Magazine," to the 

 fact that Tokio has become the headquarters of the 

 systematic study of normal every-day earth-waves 

 and abnormal movements reaching the magnitude of 

 earthquakes. These are systematically observed and 

 registered there with improved instruments of great 

 delicacy, some placed on the ordinary surface of the 

 plains, some on mountains of various elevations, and 

 others underground in coal-mines. 



In the utilisation of coal-mines for scientific 

 research the Japanese have already left us far behind, 

 in spite of the great development and antiquity of 

 our collieries. Subterranean electrical currents ; mi- 

 crophonic and telephonic examination of the sounds 

 produced by the movements of solid rock ; comparing 

 seasonal earth-waves underground with those they 

 have already observed on the surface ; the action of 

 the tides upon the roof of workings of the coal-mines 

 under the sea, and measurement of the delicate 

 tremors indicated by a tromometer devised for the 

 purpose, are some of the scientific work that is being 

 carried on underground. 



It is rarely that a monthly number of the " Journal 

 of the Chemical Society " fails to contain one or more 

 interesting communications from Japan, such, for 

 example, as that which I have just turned up in the 

 October number, entitled " A Chemical Examination 



of the Constituents of Camphor Oil, communicated 

 from the Chemical Society of Tokio by Hikoro- 

 kurb Yoshida, Chemist to the Imperial Geological 

 Survey." It is a research supplying much new 

 information, and quite free from the chemical 

 pedantry which I described last month. I dare not 

 venture to refer to details, but may state that the liquid 

 distilled out in preparing solid camphor is a sort of 

 turpentine, which mixes in almost every proportion 

 with ether, chloroform, alcohol, and most of the 

 essential oils ; that it dissolves several resins, such 

 as colophony, gum elemi, mastic, balsam and 

 asphalte, and therefore is suitable for the preparation 

 of varnishes. I presume that it may also be used as 

 a substitute for turpentine in diluting the linseed oil 

 medium of ordinary oil colours. Its aroma being 

 agreeable, the advantage of using it is obvious. 

 Being a bye product from the crude material, it may 

 probably be produced at little cost if in regular 

 demand. 



Electric Fishes. — Professor Du Bois Reymond 

 has communicated to the Berlin Academy of Sciences 

 and to " Naturforscher " the results of his long 

 researches on the electric organs of the torpedo. 

 One of the most remarkable of these is the variation 

 of electrical conductivity of this organ in opposite 

 directions. If a current is passed from the belly of 

 the animal to the back, i.e. in the same direction as 

 the animal electricity is generated, it meets with less 

 resistance than if passed in the opposite direc- 

 tion. The first of these is styled by the professor a 

 homodromous current, the second a heterodromous 

 current. 



The deflections of a galvanometer needle when a 

 current from an induction coil was passed in these 

 opposite directions, was 100 for the heterodromous 

 current, to 224' 7 for the homodromous. The difference 

 diminished with a weaker and weaker current, until it 

 became imperceptible. The longer the part of the 

 organ that was included in the circuit, the greater 

 the difference or " irreciprocity." 



The electric organ of the torpedo was found to 

 conduct twice as badly in a homodromous direction 

 as the muscle of a frog in the direction of its fibres, 

 and 7"5 to 12 times worse than the water of a 

 marine aquarium. In the heterodromous direction it 

 conducted 20 to 58 times worse than sea-water. 



I took a shock from the electrical eel that was 

 brought to London and exhibited many years ago, 

 and remember well that I was struck before my 

 hands actually touched the animal ; the communi- 

 cation took place through the water. It is obvious 

 that in order for this to occur, the electrical organ of 

 the fish must be a worse conductor in the hetero- 

 dromous direction than the sea-water, or the current 

 would return upon itself instead of passing through 

 the water. In this case it was fresh water, which is 

 a far worse conductor than sea-water. 



