II! 



NATURE 



\yune 2, 



cal laboratory, each student has his own place, with 

 full set of ai paratus and reagents. The laboratory is open 

 from II a.m.' to J p.m. In Botany, Prof. E. Perceval Wright 

 elves the first ten lectures to the class in the lecture-room, on 

 the general details of the structure and morphology of flowering- 

 planls. The second part of the course consists of ten demon- 

 strations on snch forms as Bacteria, Veast-mucor, Saprolegnin, 

 Oidium, Mushroom, the Alga: ; and the remaining portion is 

 criven in the College Botanical Gardens, when each student is 

 required to have a practical acquaintance with a certain number 

 of natural families. The demonstrations in Comparative Ana- 

 tomy are conducted by Prof. Macalister, F.R.S., who is fortu- 

 nate in having the resources of the gardens of the Zoological 

 Society to assist in the practical work of his class. So far as 

 the experiment has this session gone, the results have been most 

 happy, the students showing a far greater interest in their work, 

 and the demonstrations being less formal than the lectures, they 

 have greater facilities for asking questions. 



The fiftieth anniversary of the foundation of the Technische 

 Hochschule at Hanover is being celebrated during this week. 

 Numerous guests from all parts of Germany, as well as from 

 England, Sweden, Norway, the Netherlands, and Russia have 

 arrived at Hanover. 



SCIENTIFIC SERIALS 



Journal of the Academy of Natural Sciences of Philadelphia, 

 vol. 7, second series, part 4, 1874-1881. — \Vm. M. Gabb, 

 descriptions of Caribbean Miocene fossils ; descriptions of 

 new species of fossils from the Pliocene clay-beds between 

 I.imon and Moen, Costa Rica, together with notes on previously 

 known species from there and elsewhere in the Caribbean area 

 (with four plates). — Andrew Garrett, on the terrestrial mollusca 

 inhabiting the Cook's or Harvey Islands. — Dr. C. Chapman, the 

 placenta and generative apparatus of the elephant (with three 

 plates). — Dr. Joseph Leidy, on some parasites of the Termites 

 (gives full de-criptions, with figures, of the strange forms briefly 

 described in the Proceedings oi the Academy of Natural Sciences, 

 Philadelphia, for 1877. Triehonympha a^ilis is a truly extra- 

 ordinary form, possibly a protozoan intermediate betneen the 

 Gregarines and Infusoria). — Dr. Joseph Leidy, remarks on 

 Bathy^nathiis borealis. 



Zeitschrift fiir wissenschaftliche Zoologie, Bd. 35, Heft 3, 

 l88l. — Dr. J. W. Spengel, the organ of smell and nervous 

 system in the mollusca, a contribution to our knowledge of the 

 unity of the moUuscan plan (plates 17, 19). — Dr. O. Biitschli. — 

 Short contributions to a knowledge of the Gregarines: (l)on 

 the development of Gregarina [Clepsidrina) blattarum ; (2) on 

 the power of adhering in Monocystis magna, and on the pseudo- 

 navicella in the monocysts of the earth-worm ; (3) on some egg- 

 shaped Psorospermia in the intestine of Lithobitis forficatus 

 (plates 20,21). — Prof. F. E. Schulze, researches on the structure 

 and development of sponges, x. On Corticium candelabrum, 

 Schdt. (plate 22). — Dr. A. Gruber, on the process of division in 

 Euglypha alveolata (plate 23).— B. Ulianin, on the development 

 in amphipods (plate 24). — Dr. Paul Fraisse, on molluscan eyes 

 with an embryonal type (plates 25 and 26) (Patella, Haliotis, 

 Fissurella). — Dr. P. A. Loos, on the albuminiferous glands in 

 amphibia and birds (plate 27). 



Atli delta R. Accademia delle Science Fisiehe e Matematiche, 

 Napoli, vol. vii. — F. Panceri, the phosphorescence and the phos- 

 phorescent organs in some Annellida (Chjetopterus, Balano- 

 glossus, Polynoe), plates i to 4.— On the seat of the phosphor- 

 escence in some Campanularia (with a plate), and observations 

 of some new species of marine nematoid worms (Desmoscolex 

 elongatus and D. lanuginosus, EcJiinoderes meridionalis, E. 

 minutus, E. eruca, and E, spinosus, Tris/icochata inariinense, 

 n.gen. et n.sp. near Chjetosoma) ; all the new species are figured. 

 — A. Costa, notes of a visit to Egypt, Palestine, and the coasts 

 of Turkey (zoological). — V. Cesati, on a new species of Bat- 

 tarra;a (B. Guicciardiniana), with a plate. — On a collection of 

 Pterydophytes made at Borneo by Signor D. Beccari, with 4 

 plates. — G. Licopoli, on the fruit of the vine and its chief con- 

 stituents, with a plate. — G. A. Pasquale, on a new species of 

 Lonicera (Z. stabiana), with a plate. — F. Gasco, account of the 

 whale (Bahrna Biscayensis, Esch.) captured at Taranto on Feb- 

 ruary 9, 1877, with 9 plates.— G. Battaglini, on projective 

 geometry. — E. Fergola, on the dimensions of the earth.— G. 



Nicolucci, the Cola grotto near Petrella di Cappadocia, in the 

 province of Abruzzi, with three plates of animal remains. — On 

 prehistoric researches about the environs of the Lake of Lesina. 

 — L. Palmieri, on the present condition of electrical meteorology. 



SOCIETIES AND ACADEMIES 

 London 



Royal Society, May 12. — "Investigations on the spectrum 

 of magnesium," by Professors Liveingand Dewar. 



The flame of magnesium burning in air shows strongly, gener- 

 ally well reversed, the line at wave-length 2S50 (Cornu) ; a 

 strong triplet, resembling in the relative distance of its lines the 

 other ma .mesium triplets, close to the solar line M ; the well- 

 knowm triplet near L ; and a remarkable series of lines and 

 bands, generally resembling the spectra of some compounds, 

 extending from M to between L and K. Neither the strong 

 triplet at M nor this series of bands are represented in the spec- 

 trum of magnesium either in the arc or spark. These flame- 

 lines are remarkable as further evidence of the power of sub- 

 stances to emit, at comparatively low temperatures, radiations 

 of short wave-length. 



In the arc the authors notice a series of triplets, of which the 

 least refrangible lines have wave-lengths about 2767, 2736, 

 2798, 2673, 2649, 2633 respectively. These, with the well- 

 known triplets 6, and those near the solar lines L, P. 

 and S, form a series, similar to those described by the 

 authors in the spectra of sodium, potassium, and lithium, 

 in which the alternate members are sharp and diffuse, and 

 succeed one another at shorter and shorter intervals in a 

 way which indicates that they follow a definite law and are 

 probably harmonically related, though not forming a simple 

 harmonic series. They observe that the Hne w.l. 2850 is the 

 strongest line of magnesium both in the flame and arc, and one 

 of the strongest in the spark, and that it is nearly the octave of 

 the hne some time since observed by them at wave-length about 

 5710. They observe in the arc only the strongest two of the 

 quadruple group described by Cornu from the spark at wave- 

 lengths 2801, 2795, but they notice both in arc and spark a 

 group of five lines a little higher at wave-lengths about 2782, 

 27S1, 2779, 2778, 2777. All these lines, including the diflTuse 

 members of the series of triplets, they have often observed re- 

 versed when the arc is taken m one of their crucibles. The line 

 w.l. about 4570, so conspicuous in the flame, first noticed by the 

 authors in the spark, is well seen and easily reversed in the arc, 

 and they believe it to be represented in the solar spectrum by the 

 line w.l. 4570*9 in Angstrom's map. Besides these lines they 

 observe in the arc a pair of lines slightly less refrangible than 

 the pair in the spark, described by Cornu near the solar line U. 

 In the spark they observe two pairs of ghost-like lines below the 

 triplet near L, which together with the fainter two of the quad- 

 ruple group (2801, &c.), seem to suggest the possibility that 

 some of the particles of magnesium have, owing to particular 

 circumstances, their tones a little flattened in regard to these 

 particular vibrations, though the constancy in the amount of 

 displacement of the lines militates against such an hypothesis. 

 In regard to the b group, observations on the spectrum of the 

 fourth order given by a Rutherford grating of 17296 lines to the 

 inch showed that the iron line in b^ is a little less refrangible 

 than the m.agnesium line. The additional lines near this group 

 observed by Fievez they ascribe to a periodic inequality in the 

 ruling of the Rutherfonl grating, arising from an imperfection of 

 the screw of the ruling machine, which produces a series of 

 ghosts on either side of each principal line. The positions of 

 these ghosts have been investigated mathematically by Peirce 

 (Math, yournal of John Hopkins University), and observations 

 of them tally with the theory. They are embarrassing in the 

 case of bright lines, but may be detected by their changes of 

 position in the spectra of different orders. 



The magnesium-hydrogen spectrum \\hich the authors have 

 previously investigated and found to be produced at ordinary 

 and reduced pressures when both elements are present, but not 

 otherwise, they have now investigated further by obsei-ving the 

 spark discharge between magnesium poles in hydrogen, nitrogen, 

 and carbonic oxide, at pressures varying from one to twenty 

 atmospheres. They find that in hydrogen, when no Leyden jar 

 is used, the peculiar fluted spectrum of magnesium hydrogen is 

 much more brilliant at higher pressures, becoming fully equal in 

 brightness to the b group, notwithstanding the increase in 



