540 



NA TURE 



[April 4, 1895 



Russian Universilies. The Society, which began twenty-five 

 years ago with 74 members only, has now 374 active and 25 

 honorary members. 



The Karan Society of Naturalists at the Kazan University, 

 which was founded in 1S69, has also issued a similar anniversary 

 volume, in which the review of work done in botany is especially 

 valuable, as it has been written on the above plan. The volume 

 contains also an index of all papers published in the twenty- 

 seven volumes of its Bulletin and Memoirs, the titles of the 

 papers being given both in Russian and German. 



An old estimate of the frequency of earthquakes was that no 

 a day passed without a shock being felt somewhere on the 

 earth. In a new determination (Comples renJus, vol. cxx. pp. 

 577-579), M. de Montessus de Ballore obtains a much higher 

 figure. Dividing all the registers we possess into historical, 

 seismologica and seismographical, and assuming the latter to 

 be perfect, he finds, by comparing the different classes for the 

 same region, that in the first 96'24 per cent., and in the second 

 84 '48 per cent., of the total number of shocks escape record. 

 In a group of well-studied earthquake districts, with a combined 

 area of 11,691,000 sq. km., the average yearly numbers of 

 shocks for the three classes are 341 '35. 878'57. ^id 222224 

 respectively. Hence, multiplying by the proper factors for the 

 first two classes, it would appear that the total number of shocks 

 actually occurring in the above area must be estimated at 16,957 

 a year, or one in every half-hour. 



In several papers of great interest {Atii della K. Ace. dei 

 Fisiocrilici, Siena, vol. v., 1894), Prof. G. Vicentini describes 

 his new seismometrograph erected at Siena, and the seismic 

 record obtained with it from February to July, 1894. The in 

 strument consists of a heavy pendulum, ij m. in length and 

 50 kg. in mass, the base of which is connected with one end of 

 a very light vertical magnifying lever. The other end of this 

 lever is connected with the ends of two light horizontal levers 

 placed at right angles to one another. These magnify the 

 original movement of the ground seventy times, and trace fine 

 lines on two strips of smoked paper moving at the rate of 

 2 mm. a minute. With this arrangement the heavy mass, it is 

 found, remains stationary during vibrations of the ground, and 

 the trace ceases simultaneously with the removal of the dis- 

 turbing cause. For seismic purposes, the instrument possesses 

 several advantages, especially the small cost of working and 

 the rapid movement of the paper bands. In the plates accom- 

 panying the papers, copies are given of the traces produced by 

 passing carriages, by strong gusts of wind, and by several earth- 

 quakes.lhe most beautiful being those of the Japanese earthquake 

 of March 22, the Greek earthquake of April 27, and the Con- 

 stantinople earthquake of July 10. 



Sorgeon-Captain R. H. Elliot, of the Indian Medical 

 -Service, h.-is recently reinvestigated the value of strychnine as 

 an antidote against snake poison in the most thorough manner. 

 He experimented chiefly with cobra poison, but also with the 

 venom of Kujicll's viper and the krait, using frogs, lizards, 

 ducks, fowls, hares, guinea-pigs, dogs, goats, pigs, and monkeys 

 as test animals. He confirms the results of Drs. D. D. 

 Cunningham and A. A. Kanthack, that strychnine is not an 

 antidote against snake poison. 



That the German Cholera Commission has worked most 

 energetically is shown by the voluminous documents now 

 appearing in the Arlieilenaiiiiltm Kaiierlichen Gesiindheilsamle. 

 A detailed inquiry has been held into all the various outbreaks 

 of cholera which occurred in Germany between the latter part 

 of the yean 1892 and 1893, respectively, and the mass of 

 NO. 1327, VOL. 51] 



minute incidents thus collected have been brought to- 

 gether, and cover considerably over 600 quarto pages. The 

 Hamburg inquiry not unnaturally occupies the largest volume, 

 and is extensively illustrated with diagrams, &c. The Commis- 

 mission has succeeded in producing a most important and 

 valuable contribution to the study of epidemiology, and their 

 labours on cholera must long be regarded ES the standard work 

 on the subject. We only wisli that influenza, which is now far 

 more conslanily with us, and claims such an increasing number 

 of victims, might be subjected to the same crucial inquiry ; 

 possibly then, as in the case of the later outbreaks of cholera in 

 Germany, we might be in a position to take some steps to 

 efl'ectually check its apparently capricious career. 



A NEW contrivance for reading the position of the pointer in 

 sensitive balances is described by W. H. F. Kuhlmann in the 

 Zeilschrift fiir Instrumentenkunde. It has often been at- 

 tempted to save time by accurate readings with the aid of a 

 tekscope or microscope, but none of those methods have been 

 found to answer the purpose of the practical chemist or 

 physicist. Herr Kuhlmann's contrivance is at once simple .ind 

 effective. The pointer moves he/iind \h& divided scale, and the 

 face of the latter is turned towards a concave cylindrical mirror 

 attached to the central column of the balance. This mirror can 

 be adjusted to face the observer, who sees in it a magnified 

 image of the pointer rapidly moving across the magnified 

 scale. It is thus made possible to graduate the scale much more 

 finely than heretofore. The pointer must be very fine at the 

 end, but any danger of its being damaged on that account is 

 obviated by the fact of its moving between the scale and the 

 mirror, .\nolher improvement, described by Dr. Classen in 

 the same number, is an arrangement for exchanging objects and 

 weights without opening the balance case. This is accomplished 

 by making a portion of the scale pans detachable. Each scale 

 pan consists of a set of bent rods. One of these, bent into an 

 irregular shape, can be lifted out and conveyed on a circular 

 rail to the other scale pan, the latter undergoing this oper.-ilion 

 at the same time. A double weighing is no more troublesome 

 than a single weighing, and the advantages of the method, 

 especially when absolute weights are required, are obvious. 



The phenomenon of polyembryony, or the development of 

 two or more embryos in a single seed, has been the subject of 

 several investigations. It has been shown that it may be dye 

 to the division of the nucellus, or to the fusion of two ovulei, 

 or to the presence of several embryo-sacs in one ovule. Further, 

 Strasburger has found that it is often to be accounted for by the 

 ingrowth of some cells of the nucellus into the embryo-sac, 

 which there develop into adventitious embryos ; in other cases 

 he ascertained that two egg-cells are normally present in the 

 embryo-sac, which on fertilisation give rise to two embryos. 

 Finally, Dodel and Overlon showed that it was possible for the 

 synergid.-c to develop into embryos. More recently, M.Tretjakow, 

 in a short but interesting paper {Ber. d. Deutsclt. Bol. Gtsell., 

 February 1895) describes yet another cause of polyembryony. 

 In Allium odorum, in addition to the normal embryo formed 

 from the egg-cell, not infrequently the antipodal cells also give 

 origin to embryos. Sometimes only one of these develops, but 

 M. Trctjakow has observed all three antipodal cells start into 

 growth and give rise to three embryos. These antipodal embryos 

 commence their development immediately after the fertilisation 

 of the egg-cell, and the cell divisions, at least in the earlier 

 stages, correspond exactly with those in the embryo formed from 

 that cell. The Russian author, accepting the view that the 

 antipodal cells are homologous to the vegetative cells of the 

 prothallia of ferns, compares these antipodal embryos with those 

 arising by apogamy on fern prothallia. 



