May 31, 1888] 



NATURE 



119 



May 15, 1888, may be regarded as the founder of agronomic 

 science, to which he devoted many years of assiduous labour. 

 To him France is indebted for the introduction of all the more 

 useful agricultural processes. He also gave a great stimulus to 

 the associated science of meteorology, and rendered important 

 services to ballooning, especially in connection with military 

 tactics. — On the part played by atmospheric nitrogen in vegetable 

 economy, by M. E. Chevreul. A few summary observations 

 are made in reference to the memoir recently presented to the 

 Academy by MM. Gautier and Drouin. These observers having 

 announced as a result of their personal experiments and as some- 

 thing new to science that the gaseous nitrogen of the atmosphere 

 is absorbed by plants, it is pointed out that the Commission 

 appointed in 1854 to investigate the question decided in favour 

 of .M. Georges Ville's theory and against that of M. Boussingault. 

 Since then the part played by atmospheric nitrogen in the 

 vegetative process has been carefully studied both in France and 

 Germany, and hitherto the results, such as those of MM. Gautier 

 and Drouin, have tended to confirm the conclusions first arrived 

 at by M. Georges Ville. — The sardine on the Marseilles coast, 

 by M. A. F. Marion. The sardine appears yearly in these 

 waters, where a total of 409,055 kilogrammes were taken during 

 the period between March 1887 and the end of February 1888. 

 Details are given regarding the food, migrations, and breeding- 

 season of this fish.— Study of the planet Mars, by M. F. Terby. 

 Three small round spots, white and brilliant, are visible on the 

 continuation of Erebus (left or west side), when the Trivium 

 Charontis is midway from the central meridian in the eastern 

 half of the disk. These spots, at first scarcely perceptible, 

 become brighter and whiter as they approach the limb, where 

 they become diffused by irradiation like the polar spot. The 

 black line, which seems to divide the north polar spot, has been 

 perfectly visible since May 12. Facing it on the outer side is a 

 small hyperborean tract, white or snowy, but less brilliant and 

 white than the true polar spot, of which it seems at first sight to 

 form an integral part. It is evidently the same phenomenon as 

 that which has recently been simultaneously observed by M. 

 Perrotin, as well as by M. Schiaparelli. — On an electro-chemical 

 actinometer, by MM. Gouy and H. Rigollot. Copper oxidized 

 or covered with basic salts, and plunged into water or into a 

 solution of sulphate of copper, is known to undergo variations 

 of electromotor force under the action of light, effects which can 

 be clearly indicated only with intensely luminous means. But 

 the authors find that the oxidized copper plunged into a solution 

 of metallic chloride, bromide, or iodide becomes, on the contrary, 

 extremely sensitive to luminous rays even of slight intensity, and 

 may consequently be employed as an actinometer. Details are 

 given of the process by which they have constructed the apparatus 

 based on this phenomenon. — Determination of the heat of com- 

 bustion of a new solid substance isomerous with benzine, by M. 

 W. Louguinine. Five experiments with a beautiful specimen 

 of this substance, discovered by M. Grimer, give a mean of 

 10,863-9 calories for the heat liberated in the combustion of I 

 grain. The heat of combustion of benzine is much less 

 (776,000 cal.), corresponding to a body whose constitution is 

 absolutely different from that of the isomerous substance.— On 

 the Pliocene formations of the Montpellier district, by M. 

 Viguier. In this paper the conclusions are summed up of an 

 extensive investigation of this geological area. Three distinct 

 groups are determined : (1) Amusian, fresh-water deposits, 

 puddings and gravels, with remains of Elephas meridionalis ; 

 (2) Astian, also fresh-water, clays and marls, with remains of 

 Semnopithccus monspessulanus, Helix quadrifasciata, Triptychia 

 sinistrorsa, &c. ; (3) Plaisancian, marine deposits, sandy and 

 other marls, with remains of Potamirfes basteroti, Melampus 

 my otis, Rhinoceros leptorhinus, Mastodon brevirostris, &c. 



Berlin. 

 Meteorological Society, May 1.— Dr. Vettin, President, in 

 the chair. — Dr. Perlewitz spoke on aperiodic variations of tem- 

 perature. He based his researches on the observations made at 

 Berlin during the forty years 1848-87, and during ninety-three 

 years, 1 791 -1883, at Breslau. If a year is divided into halves, 

 the first half is characterized by a normal curve of rising tem- 

 perature, the second half by a similarly normal curve of falling 

 temperature. Both curves, however, show negative irregularities, 

 whose number may be very considerable in any one month : thus 

 in May these irregularities (fall of temperature) occurred on more 

 than thirteen days as against seventeen clays on which the curve 

 rose regularly ; and similarly, in October, there were more than 



twelve days on which an irregularity (rise of temperature) was 

 observed as against nineteen days with a normally falling tem- 

 perature. On the whole the number of these irregularities is 

 greater in the first half of the year than in the second, so that the 

 heat of the second half is greater than that of the first. A whole 

 series of interesting details exists in connection with the number, 

 magnitude, and periodic duration of the changes of temperature 

 during both the normal and abnormal times ; these cannot how- 

 ever be considered here. — Dr. Vettin communicated the results 

 of his observations on the daily periodicity in the velocity of the 

 wind, extending over a period of two years. From direct deter- 

 mination of the movement of smoke coming from a chimney, and 

 from observations with a home-made anemometer, he found that 

 in addition to the well-known maximum velocity of the wind 

 which occurs at midday, there is a second maximum just after 

 midnight. This latter maximum is very small in summer, but 

 in winter, on the other hand, it is much greater and even exceeds 

 that maximum which occurs at midday. This second maximum 

 is not very marked as an average on the whole year. The 

 speaker then gave a detailed description of the construction of his 

 anemometer, which he exhibited to the Society. He further 

 described a spring vane which he had made, which he has erected 

 at the window of his house in a moderately wide street ; this 

 vane indicates accurately not only the direction of the wind which 

 is blowing up or down the street, but also of any wind which 

 may be blowing over the houses at right angles to this. Experi- 

 ments made with tobacco-smoke in a glass-covered chamber have 

 shown that the wind which blows over the houses gives rise to 

 ascending and descending currents of air along their walls, causing 

 an elevation or depression of the vane. The vane also records 

 accurately the direction of a wind which blows at any angle other 

 than at right angles to the axis of the street. Suitable as this 

 spring vane is for observers who live in narrow streets, it is 

 specially adapted for observations in narrow mountain valleys, 

 in which the direction of the wind cannot be ascertained by any 

 other means. 



Physical Society, May 4. — Prof, von Bezold, President, in 

 the chair. — Prof. Schwalbe gave expression to the lo-s which the 

 Society had sustained through the death of Prof. Hoh, for many 

 years an active collaborator with the " Fortschritte der Physik."' 

 — In the election which then followed, Prof. Kundt, the new 

 Director of the Physical Institute, was chosen as first Vice- 

 President in the place of the late Prof. Kirchhoff. — Dr. Koenig 

 spoke on the instantaneous photographs made by Ottomar 

 Anschiitz, of Lissa, accompanied by demonstrations and examples 

 of the photographs. Anschiitz began taking instantaneous photo- 

 graphs in 1882, operating at first upon bodies of troops during 

 the manoeuvres. * Later on, at the instance of the Minister of 

 War, he photographed horses and riders moving at every sort of 

 pace. In addition, up to 1885, he busied himself with photo- 

 graphing many animals in the different and frequently very 

 bizarre positions in which they place themselves dining their 

 movements. Some of the most interesting photographs taken at 

 this time are those of storks. From 1885 onwards he has been 

 taking serial-photographs of men and animals in motion, obtain- 

 ing pictures of the consecutive stages of each movement. From 

 these serial-photographs it is possible to draw many scientific 

 deductions, by following the course of the centre of gravity of 

 the object in the successive pictures of horses and men when 

 running and jumping. A complete knowledge of the mechanics 

 of motion can, however, only be arrived at from these series of 

 photographs when the interval of time between each consecutive 

 member of the series is equal and extremely small, a result which 

 Anschiitz has nearly obtained. Latterly he has taken pictures of 

 large masses in motion, such as processions, &c. The numerous 

 photographs which the speaker exhibited and briefly explained, 

 testified completely to the technical excellence at which Anschiitz 

 has already arrived. The apparatus used for instantaneous 

 photography was exhibited at the same time. 



Physiological Society, May II. — Prof, du Bois-Reymond r 

 President, in the chair. — Dr. Koenig spoke on his measurement 

 of the intensities of light in the spectrum. The method em- 

 ployed was as follows. A circular field of vision was divided into 

 two halves, of which one was illuminated with some colour of 

 the spectrum of fixed intensity, usually with red ; the colour to 

 be compared with this was then applied to the other half, and 

 made to vary until it produced the sensation of a light-intensity 

 equal to that of the red. The first measurements were made en 

 Dr. Broddahn, whose eyes are dichromatic (green colour-blind). 



