OCTOHER i;, 1S95] 



NA rURE 



60^ 



\\\\.K\ unstaljlc, liut anuiiyemeiils have been made by which it is 

 hopecl that the- reconls may be continued. A sUyht movement 

 of the observatory towards Chamounix was iioteel, but it is ex- 

 pected that future displacements will be insignificant ; and, in 

 any case, the means are at hand to restore it t<j its orii;inal 

 position. The practicability of the establishment of oliservatories 

 on snow-clad mountains is therefore no longer to be questioned, 

 and the multiplication of such institutions as that on Mont Blanc 

 will no doubt contribute largely lc> our knowledge both in 

 meteorology an<l astronomy. 



It is characteristic of Dr. Janssen that he should taUe a<l- 

 vanlage of the opportunity of observing the aqueous bands in 

 the solar spectrum. The air above him being very rare and also ex- 

 tremely dry, he found that when oliserving sunlight in its totality 

 the bands at C" and I) were absolutely invisible, while the group 

 at a was so pale that its presence could scarcely be determined. 

 Dr. janssen already regards it as certain th.at there is neither 

 osygen nor a((ueous va])our in the solar envelopes, but the 

 question is so important that too many observations cannot be 

 made. To carry the observations a ste|i further, it will be 

 necessary, under analogous atmospheric conditions, to compare 

 very carefully the centre of the sun's disc w ith the edge, to see if 

 there is any augmentation of the o group as the limb is ap- 

 proached, this group being especially sensitive to variations in 

 the amount of absorbing vapour. 



Ki'HEMERis KOR Fave's Co.met. — The following ephemeris, 

 for Berlin midnight, is given by V. Engstrcim in Astr. Nach. 



R. A. Decl. 



h. m. s. - 



Oct. 17 ... 21 II 9 ... -4 20'6 



19 ... 12 10 ... 317 



21 ... 13 18 ... 421 



23 ... 14 32 ... 51-9 



25 ... 15 54 ... 5 l-o 



27 ... 17 23 ... 9-5 



29 ... 18 59 ... 17-3 



31 ... 20 42 ... 24-5 



Nov. 2 . 22 32 ... 31-0 



4 . . 24 28 ... 367 



... 26 30 ... 4f6 



8 ... 28 38 ... 458 



10 . . 30 52 ... 49-3 



12 ... 33 13 • 52'2 



14 



21 35 39 



•5 54-4 



The calculateil brightness is practically constant throughout 

 the above [leriod. Perihelion passage will not occur until 

 March 19, 1896. 



Visibility ok the D.ark Side ok N'e.nus. — \arious theories 

 ha\ e been advanced at different times to account for the \ isibility 

 of the hemisphere of Venus which is not illuminated bj the sun, 

 bvil there is no general agreement as to which is the most pr.ibahle. 

 Still another explanation is offered by M. Camille I'lammarion, 

 and it has the merit of being based on careful observations 

 made at Juvisy during August and September of the present 

 year {Hull. Soc. Ast. de France, October). The (ilanet was 

 frequently observed in full sunshine by M. Klammarion and his 

 assistants, and the observations appear to put the matter in quite 

 a new light. To these observers it has several times seemed 

 that the interior of the crescent of \'enus was darker than the 

 sky, even on the day of inferior conjunction. That tliis appear- 

 ance was not simply an effect of contrast produced by the 

 luminous crescent is shown by the fact that no such darkening 

 was apparent at the exterior edge of the crescent, and again by 

 the visibility of the obscure hemisphere when the luminous part 

 was artificially eclipsed. The colour of the unilluminated area 

 was slightly \iolet in all the varied conditions of observation. 

 M. I'lammarion considers that the oKservations can be best 

 accounted for by suppo.sing that \'enus is |)rojected on a some- 

 what lighter background, such as might be furni.shed by the 

 zodiacal light, or an extended .solar atmosphere. The violet tint 

 which was noted may have been due to the considerable refrac- 

 tion of the sun's rays by the atmosphere of the planet, the 

 reddish tinge thus produced on the planet appearing purple 

 when seen through our own blue sky. 



In the .same article, M. I'lammarion gives some interesting 

 facts relating to the history of the phenomenon, and some cal- 

 culations which indicate that "earth-shine'' is insufficient to 

 account for it. L'nder the most favom'able condilioiis. the 



NO. 1355, VOL. 52] 



terrestrial light received by Venus is 12,000 times feebler than 

 that received by the moon, and 822 times less intense than the 

 light we receive from the full moon. 



The Melbourne Observaiorv. — The twenty-ninth report 

 of the Government Astronomer, Mr. R. L. J. Ellery, on the 

 work of the Melbourne Observatory during the year ending at 

 the beginning of last June, has just come to hand. .Meridian 

 observations, the daily photography of the sun, magnetic and 

 meteorological observations, ha\ e been carried on as heretofore. 

 The number of plates .secured, in connection with the photo- 

 graphic chart and catalogue, up to June i, was 1080. Pre- 

 liminary measures have been made of 238 plates to obtain the 

 positions where possible, of five stars on each plate, to be used 

 for the determination of the constants of the plates. Mr. Kllery 

 refers to the important change in time-reckoning made in 

 P'ebruary la.st by the introduction of zone or standard time 

 in all the .Australian colonies. By the zone system, Kastern 

 Au.stralian time, which covers l^)ueensland, New South Wales, 

 \'ictoria, and Tasmania, conforms to that of the 150th meridian : 

 and this makes Melbourne exactly ten hours in advance of 

 Greenwich time, instead of 9h. 30m. 54s., which is the true 

 difference of longitude. The retirement of Mr. Ellery from his 

 post as Government Astronomer has already been noted in 

 these columns. Mr. Ellery has built up the Melbourne Obser- 

 vatory from its very small lieginning in 1853 to its present 

 recognised position among the national observatories of the 

 world ; and we are glad to see that the Government has 

 ap]iointed him a member of the Board of Visitors, so that he 

 has not entirely severed his connection with the observatory. 

 He has been succeeded in the directorship by the chief assistant, 

 Mr. P. Baracchi, whose pendulum observations are well known 

 to students of terrestrial physics. 



A New Obskk\'.\'iorv. — The New \'ork A'a/ioii notes a new 

 departure at the University of Pennsylvania, by the addition of 

 an astronomical observatory. The observatory has already been 

 commenced, and, when completed, it is designed to furnLsh 

 better facilities, not only for instruction, but for original research 

 as well. The new edifice is two miles from the limits of Phila- 

 delphia, and about five miles from the university l;>uildings. The 

 instruments are an eighteen-inch equatorial, with spectroscope 

 attachment, by Brashear, and a meridian circle and zenith tele- • 

 scope, each of four inches aperture, also by Brashear. The 

 mountings are by Warner and Swasey. This institution will be 

 known as the Flower Observatory, and its director is Prof. C. L. 

 Doolittle, formerly of the Lehigh University. 



OF 



THE INTERNATIONAL CONGRESS 

 PHVSIOLOGfSTS AT BERN} 

 II. 

 T^MURSD.VV morning, September 12. — Presidents: Profs. 

 •*• Dastre and Wedensky. Prof Arloing (Lyons) gave the 

 result of his researches on the persistence of electric irritability 

 in the peripheral ends of divided nerves. The author found that 

 the length of time for which electric irritability was retained 

 varied with the species of animal, and also with the individual, 

 and further ihat it was difl'erenl both for difterent nerves and for 

 the different kinds of fibres in compound nerves, such as the 

 vagus. For spinal nerves the irritability lasted from four to five 

 days in dogs, an<l from eight to ten days in horses. In one ass 

 the author obtained cardiac hihiliition with a rise of blood pres- 

 sure, upon .stimulating the peripher.al end of the v.agus fifty-seven 

 days after section : this result he attributed to a tetanus of the 

 myocardium. 



Dr. Arthus (Paris) defended tile view that the salts of calcium 

 are necessary to the coagulation of the blood, against that of 

 .Vlex. Schmidt, who does not believe their role to be an essential 

 one. He further discussed the action of neutral solutions of the 

 oxalates, fluorides, &c., in rendering the blood inco.agulable. 

 lie disagreed with Schmidt, who holds that they act specifically, 

 and maintained that their effect is due solely to the fact that they 

 precipitate the calcium salts. .Arthus repeated Schmidt's experi- 

 ments, and w,as unable to confirm his results. 



Prof. V. Kries (Freiburg) discus.sed the phenomena of colour 

 vision in eyes adapted for darkness. 



Prof Gamgee (Lausanne) gave the result of his researches on 

 the violet and ultra-violet spectrum of ha;moglobin and its 

 derivatives. He exhibited photographs which showed the 



t Continued from p. 556. 



