394 



NATURE 



\March 14, 1878 



German Polytechnic Congress. — At the recent inaugura- 

 tion of the new Polytechnic Institution of Brunswick, the 

 assembled men of science considered the question of a general 

 congress of lecturers at the German polytechnic schools. It is 

 intended to hold the congress at Dresden, and a preliminary 

 meeting of delegates will take place in the beginning of April, 

 in order to fix the programme for the congress. Dresden has 

 also been selected as the meeting-place for a congress of German 

 engineers and architects, and it is supposed that the two meetings 

 will be held simultaneously. 



Saxony. — An interesting example of the comparative sums 

 devoted in Germany to various educational purposes is to be 

 seen in the recently-issued Report of the Minister of Public 

 Instruction for Saxony, a kingdom with 2,550,000 inhabitants. 

 The whole number of educational establishments is 3,900, of 

 scholars and students, 523,000, of instructors, 6,400, The 

 salaries amount to 12,300,000 marks, and the total educational 

 expenses are 18,000,000, of which 5,000,000 are contributed by 

 the Government. The State devotes 766,000 marks to its 76 

 gymnasia and RealschuUn, 1,354,000 to the general school sys- 

 tem, and nearly as much, viz., 1,048,000 marks to the Univer- 

 sity of Leipzig with its 16 f professors and 3,100 students, besides 

 893,000 marks for pensions. The total annual cost of the 

 Leipzig University is 1,402,000 marks, or 70,100/. 



SCIENTIFIC SERIALS 



Annalen der Physik und Chemie, No. i, 1878. — The universal 

 compensator, by M. Beetz. — On the electromotive force and the 

 internal resistance of some thermopiles, by M. Beetz. — The 

 theory of stationary currents regarded from a quite general 

 stamlpoint, by M. v. Bczold. — On a tangent multiplier and the 

 electromotive force of the Grove element, by M. Riecke. — On 

 the influence of density of a body on the amount of light absoi-bed 

 by it, by M. Glan. — On the theory of the longitudinal-elliptical 

 vibrations in the incompressible ether, by M. Ketteler. — On 

 fluorescence, by M. Lommel. — On metallic reflection, by M. 

 Wernicke. — On the volume-increase of liquids through absorp- 

 tion of gases, by Messrs. MacKenzie and Nichols. — Some obser- 

 vations on Crookes's radiometer, by M. Riecke. — Determination 

 of the resonance-tones of the mouth-cavity by percussion, by M. 

 Auerbach. — On the pitch of a tuning-fork in an incompressible 

 liquid, by M. Auerbach. 



Zeitschrift fiir wissenschaftliche Zoologie, vol. xxx., part i. — 

 Rhizopod studies, by Emil Buck, 49 pp. 2 plates ; dealing with 

 the development of arcella, and a new genus parasitic on rotifers. 

 • — Revision of the genus analges (avian parasite), by G. Hallcr. 

 — Contribution to the anatomy of asteridae, by Hubert Ludwig, 

 4 plates, 63 pp., describing the water-vascular system, the 

 blood system, the nervous and the generative apparatus, the 

 body cavity. — Contribution to the natural history of the cestodes, 

 by H. A. Pagenstecher, dealing with Tania critica and Ccenurus 

 sei'ialis. 



SOCIETIES, AND ACADEMIES 



London 



Linnean Society, February 21. — W. Carruthers, F.R.S., 

 vice-president, in the chair. — Mr. Thos. Christy illustrated by 

 diagram and made remarks on M. Ossenkep's new system of 

 plant-propagation ; and he also showed the recently imported 

 fresh berries of the Liberian coffee of this year's crop. — Mr. 

 Holmes exhibited a remarkable oak gall of Aphilothrix 

 sieboldii. Hart., obtained at Willesboro, Leas, Ashford. — Mr. 

 Thiselton Dyer likewise exhibited and made a few observations 

 on the inflorescence and a drawing of the palm Pthychospenna 

 ruftcola, Thw., which had flowered for the first time in Europe 

 at Kew. — A paper, notes on the Mahwa tree {Bassia latifolia), 

 was read by Mr. E. Lockwood. This tree grows in abundance 

 in India ; a hundred thousand may be seen in the plains around 

 Monghyr. "Wild animals of all kinds greedily devour the 

 flowers, of which one tree will yield several hundredweights. 

 Besides being highly nutritious to man, it is an excellent fattening 

 agent for cattle, &c. A strong-smelling spirit is obtained by 

 distillation of the corolla, an essential oil irom the fruit, and as an 

 agent in soap making the tree is invaluable. Thus, certain yield, 

 unlimited supply, nourishing and chemical qualities, easy preser- 

 vation, and its cheapness, all combine to render it a commercial 

 product of no mean importance to our Indian empire. -^The gist 



of a "Synopsis of the Hypoxidaceae," by Mr. J. G. Baker, was 

 given. This group differs in some respects trotn the Amarylli- 

 dacese, and off'ers a close aliiance with the Bellosiceae. Four 

 genera, and between sixty and seventy species are known. The 

 Cape is their head-quarters, but some are found in Tropical 

 Africa and Angola, a very i^yj in Abyssinia and the Mascarenes. 

 None are found in Europe, Polynesia, North and Central 

 Asia, nor Extra Tropical South America. — The Secretary read 

 an abstract of a technical paper on the Schoepfiese and Cervan- 

 tesiiaD, distinct tribes of the Styraceae, by John Miers, F.R.S. — 

 Then followed a communication by Mr. Arthur G. Butler, on 

 the butterflies in the collection of the British Museum, hitherto 

 referred to the genus Euploea of Fabricius. — Dr. Hance, of China, 

 Mr. E. Milner, Dr. Geo. Shearer, and the Rev. R. Boog 

 Watson were elected Fellows of the Society. 



Chemical Society, February 21.— Dr. Gladstone, president, 

 in the chair. — A lecture entitled "Laboratory Experiences on 

 board the Challenger " was delivered by Mr. J. Y. Buchanan. 

 After describing his laboratory, which measured 10 feet by 5 feet 

 8 inches and 6 feet high, and its fittings, the lecturer gave a de- 

 tailed account of the means by which, after estimating the com- 

 pressibilities of water and mercury, he was enabled to determine 

 the depths and temperatures attained by the sounding Hue. The 

 compressibility of distilled water was found to be 0*000049 per 

 atmosphere, or 0"ooo9 per 100 fathoms ; of sea-water, 0^00077 

 per 100 fathoms ; and of mercury, 0'000027i per loo fathoms, 

 or 00000015 V^^ atmosphere. He then described the apparatus 

 and methods by means of which the amounts of oxygen, nitrogen, 

 and carbonic acid were determined. The most interesting 

 results obtained were the following : — From the surface down to 

 300 fathoms the amount of oxygen continuously decreases ; from 

 300 fathoms downwards, whatever be the depth, the amount 

 increases. This anomalous result the lecturer stated to be due 

 to the great abundance of animal life at the depth of 300 fathoms, 

 the increase in the quantity of oxygen at greater depths being 

 caused by its non-consumption, owing to the scarcity of lite. 

 The next part of the lecture dealt with the distribution of the 

 sea-water as regards density, in depth and superficially. Two 

 regions of maximum density exist north and south of the equator, 

 corresponding to the tracts frequented by the trade winds. At 

 350 fathoms deep a great zone of water of low density is found. 

 Tne densest water is found in the Atlantic. Light water is found 

 in the neighbourhood of ice and in certain regions immediately 

 after the cessation of the monsoons. The maxima of density 

 lie in the north hemisphere to the south-west, in the south to 

 the north-west of the maxima of barometric pressure. A hearty 

 and unanimous vote of thanks was given to Mr. Buchanan for 

 his interesting lecture, which was illustrated by many tables and 

 diagrams. 



Physical Society, February 16.— Prof. W. G. Adams, presi- 

 dent, in the chair. — The following candidate was elected a Mem- 

 ber of the Society: Mr. G. H. West, M.A.— Dr. Lodge read, 

 for Mr. H. F. Morley, M.A., a paper on Grove's gas battery. 

 After referring to the views of M. Gaugain and Mr. Grove him- 

 self with regard to the cause of the action of this apparatus, the 

 author proceeded to describe an elaborate series of experiments 

 he has recently made in order to ascertain the circumsiauces by 

 which it is regulated. It would be impossible to give a clear 

 account of them in a short space, but some of his conclusions 

 are as follows : — The whole of the current is due to dissolved 

 gas, and if n be the distance of the level of the liquid from the 



C R 

 top of the plate in the H tube, and E — , C being given 



1, 000 

 in galvanometric readings and R in ohms, he finds that, approxi- 

 mately, (l -^ n a) C — b + n e - {c -^ n d) E, where a, b, c, d, 

 and e are constants. The electromotive force is not constant, 

 but rises with the resistance. The current is greater in propor- 

 tion as the gas present in the elements is less ; and, finally, the 

 current appears to vary directly with the pressure. — Mr. S. C. 

 Tisley then described the harmonograph, specially referring to its 

 use for drawing pairs of curves for the stereoscope. This, the 

 latest forms of his pendulum apparatus, is capable ot giving a very 

 great variety of curves, for, in addition to rectangular vibrations, 

 parallel and elliptic motions can be combined by its means. In 

 the older form of apparatus each pendulum moves on the other 

 as a centre, whereas m the instrument described they are 

 independent. One pendulum carries at its upper end a tab e 

 which can be caused to rotate by clockwork if required. The 

 whole is supported on a kind of gimbal joint formed of two 

 pairs of knife edges at right angles, so arranged that vibration 



