yune 15, 1876] 



NATURE 



163 



peroxides, in which he described various reactions with hydrogen 

 peroxide, and also the preparation of sodium and uranium per- 

 oxides, on chromic and perchromic acids, and on the estimation 

 of nitrogen. — The Secretary read a paper, by Prof. J. W. Mallet, 

 on aluminium nitride and the action of aluminium on sodium 

 carbonate at a high temperature. The nitride forms small 

 crystalline particles of a yellow colour. — Lastly, Mr. E. Neison 

 gave a short account of a process for the estimation of mercury. 



Royal Astronomical Society, May 12. — Mr, \V. Huggins, 

 president, in the chair. — The Rev. Frederick Ilowlett presented 

 to the Society five volumes of sunspot drawings made between 

 the years 1859 and 1874. They contain several drawings of sun- 

 spots on a large scale, some of which have already been figured 

 in the pages of the Monthly Notices, and other places. A letter 

 was read from Mr. Birmingham informing the Society that Dr. 

 Schmidt's great lunar map of six French feet diameter will soon 

 be issued by the Prussian Government. It has been the labour 

 of thirty-four years, andjcontains 34,000 craters besides rills and 

 other objects. — A paper by Mr. Dunkin was read on the con- 

 junction of Venus with \ Geminorum, on August 18, 1876, 

 when there will be an excellent opportunity for making micro- 

 metrical measures of the planet's parallax with respect to the 

 star. Its nearest approach will be seen from stations in North and 

 South America a little before sunrise. — A paper by Mr. Hind was 

 read on the transit of the great comet of 1819 across the sun's disc. 

 The transit happened on its approach to perihelion, and the 

 comet was not observed until some days afterwards, when it was 

 receding from the sun. After a few weeks Olbers calculated the 

 elements of its orbit, and announced the fact that on the pre- 

 vious 26th of June it must have passed at its ascending node 

 between the earth and sun. Some five years afterwards Pas- 

 torlT wrote to the Baron de Zach to inform him that he had 

 seen the comet upon the sun's disc, and had, upon the day of its 

 transit, made a drawing of it and a measure of its distance from 

 the sun's limb. He describes it as a nebulous body 6' in dia- 

 meter with a bright centre. His original drawing is preserved 

 in the library of the Astronomical Society. Mr. Hind has care- 

 fully recalculated the elements of the comet's orbit, and has found 

 thatatthetimementionedby Pastorff the cometmusthave appeared 

 much nearer to the sun's centre than the position indicated by 

 Pastorff. Canon Stark of Augsburg, also published an account of 

 a nebulous body seen upon the sun's disc at 7h. 5m. on the morning 

 of June 26. The measures given by him of the position of the 

 black spot do not agree with the position calculated by Mr. 

 Hind, although there is less discrepancy between them and the 

 calculated position than there is in the case of Pastorff's observa- 

 tion. Mr. Hind is disposed to think that neither Stark's nor 

 Pastorff's observations are to be depended upon. — Mr. Christie 

 read a note on the displacement of lines in the spectra of stars, 

 from which it appearea that the discrepancies between the results 

 of his observations and those of Mr. Huggins only amounted in 

 the case of most of the stars which had been given by him to 

 some three or four miles per second. The meeting adjourned 

 till June 9. 



Geological Society, May 24. — Prof. P. Martin Duncan, 

 F.R.S., president, in the chair. — The following communications 

 were read : — " On the old glaciers of the northern slope of the 

 Swiss Alps," by Prof. Alphonse Favre. The author said that 

 in existing glaciers two parts may be recognised, — an upper one, 

 the reservoir or feeding glacier, and a lower one, the flowing 

 glacier. Applying this division to the old glaciers, it appears 

 that in the glaciers of the Rhone and Rhine the flowing glacier 

 which occupied the plain had a surface nearly equal to that of 

 the feeding glacier which was situated in the mountains. He 

 showed (i) that the Rhone glacier passed over several of the 

 chains of the Jura, and that the ice covering these, far from being 

 an obstacle to the extension of the glaciers of the Alps, actually 

 reinforced them, and served them as relays, the glaciers of the 

 Jura having carried far on the Alpine erratic blocks ; (2) that 

 the slopes of the upper surface were variable, and were null, or 

 nearly so, over considerable spaces. During their greatest exten- 

 sion the Swiss glaciers came in contact with those of central 

 France near Lyons ; they united with those of the Jura, the 

 Black Forest, and the Austrian and Italian Alps ; they stretched 

 from the plain of the Po to that of the Danube ; and further, 

 for distances of 50 or 100 kilometres they nearly approached 

 horizontality. Hence they resembled the glaciers of the interior 

 of Greenland and Spitzbergen, so far as can be judged from the 

 descriptions. ^Evidences of Theriodonts in Permian deposits 

 elsewhere than in South Africa, by Prof. R. Owen, F.R.S. In 



this paper the author noticed some described reptilia which he 

 believes to belong to his order Theriodontia. The genus Euro- 

 saiirus was founded in 1842 by Fischer von Waldheim upon 

 some fragments of bone, including a humerus with a broad 

 proximal end as in Kutorga's Orthopus ; and Fischer also noticed 

 a humerus showing characters like those of Kutorga's Britkopus, 

 from the same locality as the portion of a jaw described under 

 the name of Rhopalodon IVangenheimii, Fischer, In 1858, H. 

 von Meyer described a skull from the Permian of the Oural, 

 under the name of Mecosaurus uraliensis, as a Labyrinthodont ; 

 and Eichwald referred this genus, with Kutorga's Brilhopus and 

 Orthoptic, to Fischer's Eurosaurus. The author regarded 

 Mecosaunts as truly Labyrinthodont ; whilst the Permian forms 

 constituting Kutorga's genus were referred to the Theriodont 

 order. From the same locality as the above Kutorga describes 

 Syodon biarmicum as probably a Pachyderm. Its teeth 

 resemble those of Cynodraco. Eichwald's Deuterosaurus biar- 

 micus is founded upon the fore part of both upper and lower 

 jaws of a reptile, containing teeth with denticulate or crcnulate 

 trenchant borders, the canines being large, especially in the 

 upper jaw. Deuterosaurus closely resembles Cynodraco, and 

 stiil more the Lycosaurus of the Karoo beds of the Sneewber"' 

 range. All the above are from the Permian beds of the Oural^ 

 and the author regards them as furnishing important evidence of 

 the Palaeozoic age of the Karoo series, in which the Theriodont 

 reptiles are best represented. The author further noticed a 

 Theriodont allied to Lycosaurus from a red sandstone, probably 

 of Permian age, in Prince Edward Island. The remains include 

 the left maxillary, premaxillary, and nasal bones ; the teeth, 

 implanted in distinct sockets, have sub-compresied, re-curved, 

 conical, pointed crowns, with minutely crenulated borders. 

 This fossil has been described by Dr. Leidy under the name of 

 Bathygnathus borealis. Thus, supposing the affini ties of the fossils 

 from the Oural and Prince Edward Island to be correctly deter- 

 mined, the reptilia distinguished by mammalian character? are 

 shown to have had a very wide range. Further, the author 

 thinks that the Theriodont reptiles of the Bristol Dolomitic 

 conglomerate may also prove to constitute a family in the Therio- 

 dontic order. 



Physical Society, May 27.— Prof. Gladstone, vice-president, 

 in the chair. — The following candidates were elected members 

 of the Society : — Herbert Taylor, Rogers Field, and Channell 

 Law. — Mr. W. Ackroyd read a paper on selective absorption. 

 Two typical experiments were shown upon which a division of 

 selective absorption may be based. In the first, light is trans- 

 mitted through bichromate of potash at the normal temperature 

 and again at about 200° C. ; and the spectrum of the transmitted 

 light is examined. The widening of the absorption-bands which 

 takes place at the higher temperature is traced to structural 

 alterations. In the second experiment light is sent through two 

 thicknesses of the same coloured solution, as, for example, sul- 

 phate of copper, and in the greater thickness the absorption- 

 band has widened out, but this is plainly not owing to any struc- 

 tural alteration. That in the first experiment he proposes to 

 term structural, and that in the second tra?tsverse absorption, and 

 he considers that these two kinds have not hitherto been suffi- 

 ciently distinguished. Certain colour relations which exist 

 among anhydrous binary compounds led the author to the con- 

 clusion that the width of a structural absorption-band bears a 

 direct relation to interatomic distance. The necessity for sepa- 

 rating high temperature spectra from low was shown, and the 

 bearing of the subject on the study of organic colouring matters 

 briefly alluded to. — The Secretary then read a communication 

 from the Rev. R. Abbay, on certain remarkable atmospheric 

 phenomena in Ceylon. The most striking of these is witnessed 

 from the summit of Adam's Peak, which is a mountain rising 

 extremely abruptly from the low country to an elevation of 7, 200 

 feet above the sea. The phenomenon referred to is seen at sunrise, 

 and consists apparently of an elongated shadow of the mountain 

 projecting westward to a distance of about seventy miles. As 

 the sun rises higher it nxpidly approaches the mountain and ap- 

 pears at the same time to rise before the observer in the form ot 

 a gigantic pyramid of shadow. Distant objects may be seen 

 through it, .so that it is not really a shadow on the land, but a 

 veil of darkness between the peak and the low country. It con- 

 tinues to rapidly approach and rise until it seems to fall back 

 upon the observer, like a ladder which has been reared beyond 

 the vertical, and the next instant it is gone. Mr. Abbay sug- 

 gests the following explanation cf the phenomenon : — The 

 average temperature at night in the low country during the 



