422 



NATURE 



[September i, 1898 



Machinery — the South African journal of engineering, mining, 

 and science"^announces that the State geologist, accompanied by 

 Mr. David Draper, has gone to St. Lucia Bay to investigate the 

 connection between the Karoo Beds of the Vryheid District 

 with those of Natal and the High Veld. A geological section 

 of the country will be made from Volkrust eastward, which 

 should be of much value to geologists. 



The Tratisactions of the Edinburgh Geological Society 

 (vol. vii. part 3) contains a large number of interesting papers 

 and notes on geological subjects. Amongst the longer papers 

 we notice two, by Mr. H. M. Cadell, on the geological features 

 of the coast of Western Australia, and on the New Zealand 

 volcanic zone, and one, by Mr. J. G. Goodchild, on desert con- 

 ditions in Britain. In a footnote Mr. Goodchild states that 

 during the past three years he has taught in his classes that the 

 Torridonian rocks were formed under desert conditions, and that 

 he is not aware that this idea has occurred to any other geologist. 

 The point is important in view of Prof. Penck's recent dis- 

 cussion of the same subject. 



In the latest volumes of its Memoirs the Russian Geographical 

 Society has published the diaries of three expeditions made in 

 East Siberia many years ago, but the detailed accounts of which 

 had hitherto remained unknown. Two volumes are given to 

 two diaries of the mining engineer, I. A. Lopatin, who visited 

 the northern parts of the Vitim plateau in the year 1865, 

 and the next year travelled along the Lower Yenisei to 

 Turukhansk. The former contains a wealth of minute descrip- 

 tions of the granites, gneisses, and crystalline slates of the Vitim 

 plateau, all described from Lopatin's samples by specialists, 

 as well as of the mantles of basalt which cover large 

 portions of the plateau along its north-western edge. The 

 second volume is even more interesting, as on his journey down 

 the Yenisei Lopatin met not only Laurentian and Huronian 

 formations, but also widely-spread Silurian rocks. Quaternary 

 deposits, and Post-Pliocene deposits of the Arctic Sea, very 

 rich in sub-arctic shells (all fossils were described years ago 

 by Fr. Schmidt in his " Mammuthexpedition "). The third 

 volume of this series contains the diary of the remarkable 

 explorer, A. L. Czekanowski, of whose expedition to the Lower 

 Tunguska, the Olenek and the Lena, in 1873-75, Fr. Schmidt 

 rightly says that it was richer in geological results than any of 

 the expeditions that have explored Siberia. The results of this 

 journey were well known through Czekanowski's preliminary 

 reports, as well as through the descriptions of his palseont- 

 ological and botanic collections by Oswald Heer, Lagusen, 

 Moisisowicz, Fr. Schmidt, and Trautvetter. But a full descrip- 

 tion of the expedition was never published, and it is only now 

 that Czekanowski's diary, which contains a mass of most valu- 

 able information, sees the light. Fr. Schmidt contributes to 

 this volume a sketch of the tragic life of the author, who was 

 exiled to Siberia after the Polish insurrection of 1863 ; then, 

 after several years spent in hard labour, was allowed to make 

 his memorable journeys, and was permitted to come to St. 

 Petersburg in 1876. He was not allowed, however, to remain 

 in the Russian capital, and being compelled to return to the 

 land of exile, he poisoned himself at the age of forty-four. An 

 excellent portrait of this remarkably energetic worker is given 

 in the volume which contains his posthumous work. 



A SUMMARY of recent advances in the photography of air 

 waves, formed by flying projectiles, is given in Engineering for 

 August 12, accompanied by a number of fine illustrations. Per- 

 haps the most interesting recent development of the subject is to 

 be found in the attempts of Mach to study the phenomena by 

 means of interference bands. From these it is concluded that 

 though the air is pushed forward and outward by the projectile, 

 NO. 1505, VOL. 58] 



the compression does not, in the case of a steel shell, correspond 

 to more than a pressure of a fifth of an atmosphere ; further, 

 there is, indeed, something like a vacuum immediately behind 

 the projectile, but this vacuum only extends through a short 

 distance. 



A PRELIMINARY note on the influence of electricity on the 

 sedimentation of turbulent liquids, is contributed to the Bulletin 

 de V Acadhnie royale de Belgique by M. W. Spring. After 

 observing that water will sometimes hold finely divided matter 

 of greater density than itself in suspension for an indefinite time, 

 but that the presence of small quantities of salts in solution, or 

 heating the liquid, will suffice to bring about precipitation, M. 

 Spring states that a medium formed of pure water containing 

 finely divided silica, or other non-electrolytic matter, begins to 

 clarify gradually as soon as two platinum electrodes are plunged 

 into it and a current passed through them. From this experi- 

 ment the author proposes to develop a theory according to which 

 the turbulent state is caused by a modification of the electric 

 state of the finely divided particles, caused by the change in the 

 energy of attraction of the matter forming them, consequent ork 

 disintegration. The presence of a dissolved salt or acid renders 

 the liquid a conductor, and the discharge of electricity causes the 

 particles to collect in flocculent masses ; an explanation in accord- 

 ance with Bodlander's view, that only electrolytes are capable of 

 producing clarification. Again, convection currents produced 

 by warming the liquid give rise to electric currents which alsa 

 have the same eff'ect. M. Spring proposes to go further and 

 explain the fall of rain accompanying thunderstorms on the same 

 theory. We wonder if he has thought of trying the effect of 

 Rontgen rays on turbulent liquids ; if not, his present theory 

 suggests that the results of doing so might be interesting. 



In Tasmania, writes Mr. Stuart Dove in Nature Notes, the 

 "blue-tongued lizard," the Tiliqua nigrolutea of naturalists, 

 takes the place of that noted cobra-destroyer, the Indian mon- 

 goose. The blue-tongued lizard is a stout formidable-looking 

 animal much given to lying about the bush roads and tracks, 

 asleep in the sun, which heaviness of disposition has earned for 

 it the name of " sleeping lizard." But should a snake come in 

 sight, the sleepiness disappears instantly and every nerve of the 

 lizard seems on the alert, every sinew toughened to meet the 

 enemy. The snake usually tries to get away, but the lizard 

 prevents it, and a fight commences, the two reptiles darting and 

 dodging and savagely snapping at one another. The snake 

 soon shows signs of being exhausted, and the lizard then twists 

 it over with a quick dexterous turn and gives it a coup de grace. 

 The lizard afterwards takes the head of the snake between its 

 strong jaws and slowly devours the dead reptile, after which he 

 retires to the shelter of a hollow log to sleep off the repast, 



A SHORT but interesting paper by Prof. W. C. Mcintosh, on 

 the memory of fishes, is referred to in the Journal of the Royal 

 Microscopical Society {A-agwsi). Prof. Mcintosh refers to "the 

 behaviour of a large grey skate in its endeavour to escape over 

 a trawl-beam more than fifty feet long, which had been arrested 

 in its rise — ^just above the surface of the sea — by a temporary 

 block in the machinery. The dexterity with which it skimmed to 

 and fro along the beam to find where it dipped sufficiently during 

 the movements of the ship to enable it to glide over was a study. 

 . . . If those who have given a green cod of six or eight inches 

 a particular kind of ' scale-back ' (a kind of worm), and noticed, 

 firstly, how eagerly it seized it, then tested it in its pharyngeal 

 region, and soon ejected it, never again taking that species into 

 its mouth, they would be slow to deny that fishes, and even 

 very young fishes, have a memory. " A number of very sug- 

 gestive cases are given, and the author concludes : " With 

 regard to the absence of cortex of the brain in fishes, this is 

 probably only a question of degree — easily understood by re- 



