December 26, 1895] 



NATURE 



79 



A POSSIBLE method of determining the directions of 

 atmospheric currents at high altitudes, independently of the 

 observations of cloud movements, was suggested by Seiior V. 

 Ventosa, of the Madrid Observatory, in 1890 ; since then he has 

 continued the investigation with great perseverance. The basis 

 of the method consists in the observation of the undulations 

 round the sun's limb, which are so trying to solar observers. In 

 their greatest simplicity, these waves are tangential to the disc at 

 two diametrically opposite points, and cut normally in the 

 positions at right angles, all of them trending in the same 

 direction. Usually, however, there are several superposed 

 systems, and the difficulty is to separate them clearly one from 

 another. The wind near the earth's surface is not often found to 

 affect the appearances on the sun's limb, the explanation being 

 that the waves produced by such a current must be greatly out of 

 focus in the telescope. In fact, by varying the position of the 

 eye-piece and determining the displacement necessary to bring 

 the different systems of waves most clearly into view, the corre- 

 sponding altitudes of the currents producing them can be found 

 by applying the ordinary formula for conjugate foci. A large 

 number of observations of this nature have been accumulated by 

 Seflor Ventosa, and as a control, observations of clouds have 

 also been made ; a tabulation of results certainly seems to indicate 

 that the new method may be useful. Generally speaking, the 

 direction of the superior currents is unlike that of the wind near 

 the surface of the earth. A result of some interest is that on 1 50 

 days on which two currents were indicated, the mean height of 

 the " neutral plane " was 2430 metres. It also appears that as 

 the altitude increases the direction of movement usually changes 

 in the opposite direction to the hands of a watch. The method 

 seems to be well worth further investigation. 



Two important papers have recently been published on the 

 effect of the electric light and of electricity on vegetation. The 

 first is by M. Bonnier in the Revue Ghi^rak de Botaniqtie. He 

 states that a continuous electric light promotes the formation 

 of chlorophyll, and brings about, at the same time, a simpler 

 anatomical structure of the leaves. Under a continuous electric 

 light the distribution of the chlorophyll in the tissues is more 

 extended than in ordinary daylight ; chlorophyll-grains make 

 their appearance in the cortex as far as the endoderm, and even 

 in the medullary rays and the pith. The palisade-tissue of the 

 leaf is reduced, or entirely disappears, and the epidermal cell- 

 walls are thinner. The bark is less developed, and the various 

 tissues of the stem are less differentiated. When the electric 

 light is discontinuous, as, for example, when turned on twelve 

 hours out of the twenty-four, the effect on vegetation is inter- 

 mediate between that of normal sunlight and that of a continuous 

 electric light. Alpine plants cultivated under a continuous 

 electric light exhibit points of structure identical with those of 

 Arctic plants, which are exposed to almost continuous sunlight 

 in the summer. The other paper is by Prof. A. Aloi in the 

 Bulletino of the Italtan Botanical Society. He adduces evidence 

 in favour of his view that both terrestrial and atmospheric elec- 

 tricity exercise a favourable influence on the germination of 

 seeds and on the growth of plants, and predicts that the em- 

 ployment of electricity will be a most important factor in the 

 aigriculture of the future. 



We have received a valuable memoir on the Greek earth- 

 quakes of 1894, from Dr. S. A. Papavasiliore, the director of the 

 geodynamic section of the observatory of Athens. We have 

 already (vol. 1. p. 607) given a full account of these shocks, in 

 summarising two preliminary papers by the same author. 



The Roman earthquake of last November I, is the subject of 

 a short paper read by Prof Tacchini before the Reale Accademia 

 deiLtnceiC' Rendiconti," vol. iv., 1895, PP- 221-223). The area 

 over which the shock was perceptible, without the aid of instru- 



NO. 1365, VOL. 53] 



ments, contains about 11,600 sq. km. The epicentre was 

 probably near, or under the sea, in the neighbourhood of Ostia. 

 Dr. Cancani estimates the depth of the seismic focus at about 

 1 5 km. Beyond the limits of the disturbed area, the shock was 

 registered by microseismc^raphs at Ischia, Siena and Florence. 

 The times recorded by Prof. Tacchini, for Rome and Siena, give 

 a velocity of almost exactly 2 km. per second. 



In the last number of the Ornithologische Monatsberichte 

 {1895, p. 196) will be found an announcement that the German 

 Zoolc^ical Society of Berlin has in contemplation a very im- 

 portant work, which will be entitled " Das Tierreich. Erne Zu- 

 sammenstellung und Kennzeichnung der rezenten Tierformen." 

 The somewhat ambitious aim of this publication is, if we under- 

 stand rightly, to give on an uniform plan descriptions of all the 

 known species of the animal icingdom, together with their dis- 

 tribution and most important synonymy. Prof. F. E. Schultze, 

 of Berlin, has undertaken the general editorship of this work, 

 but will be assisted by specialists in the different branches of 

 zoology. 



The Royal Meteorological Institute of the Netherlands has 

 made a valuable contribution to maritime meteorology by the 

 publication of a large folio atlas of the Guinea and equatorial 

 currents, embracing that part of the Atlantic Ocean betweerk 

 lat. 2' and 24° N., and from the west coast of Africa to long. 

 29° W., which includes the limits of the African North Polar 

 current. The charts, of which there are several for each month, 

 show clearly how the Guinea current divides into two branches, 

 one setting to N.E. and the other to S.E., the various changes in 

 the temperature of air and sea-surface, the regions of trade winds, 

 calms, rain and other phenomena. The principal direction of 

 the Guinea current being towards the east, while the equatorial 

 currents set towards the west, the former is represented in black 

 and the latter in red. The materials for the charts have beer* 

 obtained entirely from Ic^s kept on Dutch vessels. 



An interesting paper by Miss Grace E. Cooley is reprinted 

 from the Memoirs of the Boston Society of Natural History, on 

 the reserve-cellulose of the seeds of Liiiacece and of some related 

 orders. She states that reserve-cellulose appears, as such, on 

 the walls of the cells soon after the endosperm is formed. Sugar 

 and oil are present in the cells before the appearance of reserve- 

 cellulose and during the process of the thickening of the wall, 

 the sugar being formed first. The reserve-cellulose appears first 

 at the angles of the cells, and extends thence to the walls. The 

 cells of the endosperm near the chalaza are the first to have 

 their walls thickened ; those next the integuments are next 

 affected, and the cells near the embryo are the last to mature. 

 The paper is illustrated by six quarto plates. 



A VALUABLE monc^raph on water supplies, by Mr. Allen 

 Hazen has just been published, and should prove of great value to 

 engineers and others in charge of water-works. Mr. Hazen was 

 lately chemist in charge of the well-known Lawrence experi- 

 ment station of the Massachusetts State Board of Health, and 

 is, therefore, specially qualified for the task he has undertaken, 

 and in the carrying out of which he has been so successful. No 

 trouble has been spared to obtain the latest and most trust- 

 worthy information on water- works from all parts of the world. 

 The change which has come over the conduct of water-works 

 since the introduction of the modern methods of bacteriology 

 is, of course, shown very clearly, and it is pointed out how, in 

 our country, Dr. Percy Frankland's investigations, published in 

 1885, on the removal of bacteria by means of sand -filtration at 

 the London Water-works, and in Germany those of Wolflhiigel, 

 Plagge and Proskauer at the Berlin Water-works, published in 

 1886 and 1887, were the means of furnishing the first insight 

 into the hygienic significance of filtration. 



