February 15, 1906] 



NA TURE 



the solution in series, the constancy of weight of the second 

 vessel indicates that the air has been saturated up to the 

 vapour pressure of the solution. The total quantity of 

 vapour given off by the solution and solvent is absorbed 

 by sulphuric acid, and the gain in weight of the latter 

 should equal the loss sustained by the two former. With 

 solutions in water, it is pointed out that, on account of 

 the condensation of solvent in the tube leading to the 

 sulphuric acid, this never quite obtains. The loss of weight 

 of the solution in conjunction with that of the solvent 

 give, however, the data for calculating the osmotic pressure. 

 It is shown that Arrhenius's formula, when applied to 

 concentrated solutions, does not connect the true osmotic 

 pressure with the lowering of vapour pressure; and a more 

 correct relation is deduced from a consideration of the 

 hydrostatic pressures about a column of solution which is 

 closed at the lower end by a semi-permeable membrane, 

 and is partially immersed in the solvent. It is found that 

 the osmotic pressures of cane-sugar solutions when calcu- 

 lated by way of vapour pressures and when observed 

 directly agree to within 5 per cent, of one another over 

 .1 range of 20 to no atmospheres. 



January 25. — " Artificial Double Refraction, due to 

 .-Eolotropic Distribution, with Application to Colloidal 

 Solutions and Magnetic Fields." By Dr. T. H. Havclock. 

 Communicated by Prof. J. Larmor, Scc.R.S. 



The sections of the paper are summarised as follows : — 



(1) The formal investigation of artificial double refraction 

 in colloidal solutions as due to a deformation of the medium 

 consisting of a change in the packing of the colloidal 

 particles. 



(2) The possibility that such deformation may be produced 

 by mechanical stress as arising from the possession of a 

 certain amount of rigidity bv such solutions. 



(3) The analogy between the effects so produced and the 

 double refraction due to a magnetic field. 



Linnean Society, January 18. — Prof. W. A. Merdman, 

 F.R.S., president, in the chair. — Coloured transparencies 

 from flowers in natural colours : T. E. Waltham. — The 

 life-history of Margaritifera Panasesae : A. W. Allen. The 

 paper was interesting as the result of close observation in 

 the field, though practically all had been observed by 

 other observers in various parts of the world, and of various 

 nationalities. — Some endophytic algae : A. D. Cotton. 

 The observations referred chiefly to Endodcrma viridc, 

 Lagerh., which occurs abundantly in the tissues of Nito- 

 phyllum Hilliae, Grev., a deep-water alga, only obtainable 

 by dredging. The author also gave the result of his study 

 of Streblonema intestinum, Holmes and Batters, based upon 

 Reinsch's preparations in the Kew herbarium. — The 

 organ of Jacobson in Sphenodon : Dr. A. Broom. 



February 1. — Prof. W. A. Herdman, F.R.S., president, 

 in the chair. — The Percy Sladen Trust Expedition in 

 11. M.S. Sealark to the Indian Ocean: J. Stanley 

 Gardiner. Accounts of the work and results of the ex- 

 pedition were given by Mr. Gardiner in Nature of April 13, 

 August 10, October 5, November 9, December 21, 1903, 

 and January 25 of the present year. 



Anthropological Institute, January 23. — Prof. W. Gow- 

 land, president, in the chair. — Annual meeting. — 

 Annual address : copper and its alloys in antiquity : 

 President. Smelting had its origin in the camp fire, from 

 which the first primitive furnace, a hole in the ground, 

 used even now in parts of Japan, naturally evolved. The 

 lumps of copper discovered in " founders' hoards " had 

 clearly been smelted in this way. The hole was first filled 

 with charcoal, over which was placed the ore, then another 

 layer of charcoal, then more ore, and so on ; the draught 

 was obtained by the wind or by primitive bellows. The 

 smelted copper was not run off, but, at the moment of 

 solidification, was pulled out of the fire and broken into 

 pieces on a large stone. This system is still practised in 

 Korea, while the implements used by primitive man have 

 their counterpart at the present day in the tools used by 

 the native smelters in some parts of Africa. Turning to 

 the question of bronze, Prof. Gowland stated that in his 

 opinion this was made directly from a copper ore containing 

 tin, long before the two metals were mixed. In Hungary 

 a copper ore containing antimony takes the place of a 



NO. 1894, VOL. -JT,) 



copper-tin ore, and the implements found there frequently 

 contain antimony in considerable amounts. He defined 

 bronze as an alloy of copper and tin containing not less 

 than 2 per cent, of tin ; lead, arsenic, zinc, &c, being 

 present in very small quantities. The president was of 

 opinion that there was no evidence of a true Copper age 

 in Europe, excluding only Cyprus, which was, of course, 

 exceptional. Copper implements were onlv used by primi- 

 tive man as adjuncts to stone implements, which were 

 more efficient as weapons, and when found are only copies 

 of stone implements, or when made in the Bronze age 

 take the form of the implements of that period. In its 

 simple form a copper celt could only be made in an open 

 mould, and therefore only fiat celts could be made of 

 copper. The opinion often maintained, that the intention 

 of the makers of bronze weapons was to make an imple- 

 ment in the proportion of 9 : 1, was shown by analysis to 

 be incorrect, as also was the theory that the art of temper- 

 ing bronze was lost, as it could now be hardened by 

 hammering as well as, if not better than, it was done in 

 the Bronze age. The lecturer also clearly proved that 

 metallic tin was not necessary to the manufacture of 

 bronze, and bronze celts made by him by melting metallic 

 copper with tin ore, and from metal obtained by smelting 

 a mixed ore of copper and tin in a primitive furnace in 

 the metallurgical workshop of the Royal School of Mines, 

 were exhibited. He also showed conclusively that the 

 opinion held by many of the existence of a universal Copper 

 age in Europe, intermediate between the Bronze and Stone 

 periods of culture, was not warranted by the facts of the 

 case. 



Geological Society, January 24. — Dr. J. E. Marr, 

 F.R.S., president, in the chair. — The igneous and 

 associated sedimentary rocks of Llangvnog (Caermarthen- 

 shire) : T. C. Cantrill and H. H. Thomas. The sedi- 

 mentary rocks associated with the igneous masses com- 

 prise Lower Old Red Sandstone, Didymograptus-bifidus 

 beds, and Tetragraptus beds of the Ordovician. They 

 occur in two anticlines, overfolded, and complicated by 

 thrusts. The igneous rocks occur in three well defined 

 areas, which belong to the same petrographical province. 

 Both interbedded and intrusive rocks are represented ; the 

 latter include diabases and a large porphyry mass. The 

 extrusive rocks occur in the following order : — (1) augite- 

 andesites ; (2) rhyolites ; and (3) augite-andesites. The 

 extrusive rocks are interbedded with fluxion-breccias and 

 with tuffs ; they are associated with the lower members 

 of the Tetragraptus beds, and are consequently of Lower 

 Arenig age : while the intrusive rocks have been injected 

 into the extrusive rocks, and have also affected the Tetra- 

 graptus beds. — The Buttermere and Ennerdale granophyre : 

 R. H. Rastall. From the facts put forward it is con- 

 cluded that the intrusion is an example of an acid-magma, 

 which has crystallised under the set of conditions that 

 gives rise to a perfect development of granophyric struc- 

 ture. The masses appear to be of the " cedar-tree " lacco- 

 lite type intrusive about the junction of the Skiddaw 

 Slates and the Borrowdale rocks. Besides the normal 

 acidic rock, there are some marginal patches of more 

 basic character, showing obvious genetic relationship. 

 These basic forerunners afford evidence of differentiation 

 of the magma before intrusion — an example of Prof. 

 Brogger's deep-magmatic differentiation. Considered as a 

 whole, the character of the magma shows closer affinity 

 to the tonalite group than to the true granites. The more 

 basic types include dolerites, quartz-dolerites, and a rock 

 type intermediate between quartz-dolerites and granophyres. 

 There is also a development of peculiar rock types as the 

 result of the re-mixing of previously differentiated partial 

 magmas of an acid and a basic character respectively. 



Challenger Society, January 31. — Dr. R. N. Wolfenden 

 in the chair. — Four deep-water Carida? from the west coast 

 of Ireland : S. W. Kemp. Acanthephyra purpurea, a 

 species showing so great variation that it is now possible 

 to rank six other "species" as its synonyms; .1. debilis, 

 a very rare species with about 100 luminous organs ; 

 Mgeon brendani, and Leontocaris lar, spp. nn. — Report 

 on the Cha?tognatha of the Siboga expedition in the Dutch 

 East Indies : Dr. Fowler. Of sixteen species, only one 

 appeared to be new. Among those taken only in deep 



