\ 



July 28, 1923] 



NATURE 



151 



^ Societies and Academies. 



London. 



The Faraday Society, July 2. — Prof. A. W. Porter, 

 past-president, in the chair. — A. Ferguson : On a 

 relation between surface tension and density. Macleod 

 has shown empirically that for a number of un- 

 associated liquids, 7 = C(pi-p«)*, where 7 is the 

 surface tension of the liquid at any temperature, 

 Pi - p^ the difference between the orthobaric densities 

 of the liquid and the vapour at that temperature, 

 and C a constant which is independent of the tem- 

 perature. This expression is referred to the power 

 law connecting surface tension and temperature 

 first put forward by van der Waals but not generally 

 known, and the Eotvos equation. — U. R. Evans : 

 The law of definite proportions in the light of modern 

 research. Many of the series of solid solutions met 

 with in alloys show a maximum melting-point {i.e. 

 a maximum thermal stability) at a composition 

 indicated by a simple atomic formula {e.g. AuMg) ; 

 it is customary to describe this member of the series 

 as an " inter-metallic compound," and to regard it 

 as the parent of the series. But in cases where there 

 is a maximum hardness {i.e. maximum mechanical 

 stability) at a composition indicated by a simple 

 atomic formula {e.g. AgAu), or where there is an 

 abrupt change of chemical behaviour (a parting limit), 

 it is not at present customary to apply the word 

 " compound.". The fact that the maximum stability 

 usually occurs at a composition expressible by a 

 simple formula is often capable of a physical ex- 

 planation. Many of the oxides of metals with more 

 than one valency have a variable composition ; e.g. 

 pure FcgOi and FegOa may be regarded as the " end- 

 members " of a series. Likewise homogeneous 

 bodies of variable oxygen-content occur among 

 the oxides of platinum, iridium, nickel, molybdenum, 

 tungsten, and possibly silver, lead, and thallium. 

 Chlorides of thallium, sub - chlorides and sub- 

 bromides of bismuth, and sulphides of copper, nickel, 

 and cobalt show similar series of homogeneous 

 substances. — J. Grant and J. R. Partington : Con- 

 centration cells in methyl alcohol. The E.M.F. of 

 concentration cells formed from solutions of silver 

 nitrate in methyl and ethyl alcohols as determined 

 by Wilson agrees with that calculated from Nernst's 

 formula only for the latter. Good agreement has 

 been found, however, in both cases. — F. G. Tryhorn 

 and S. C. Blacktin : The formation of anomalous 

 Liesegang bands. Two examples of the production 

 of anomalous Liesegang bands are cited in addition 

 to the case of lead chromate in agar gels first noticed 

 by Hatschek. The substances formed crystallise 

 from the respective gels more readily in the light than 

 in the dark.— J. B. Firth : Determination of the 

 density of charcoal by displacement of liquids. It 

 has been shown that the apparent densities of cocoa- 

 nut shell charcoal and sugar charcoal have been 

 determined after definite intervals, for several liquids. 

 The values obtained increase with the time of contact 

 between the liquid and the charcoal. Further, the 

 final density value varies with the different liquids. 

 It would appear that the rate of change in the density 

 value and also the final density will be determined 

 by the rate of sorption and sorptive capacity re- 

 spectively. 



Edinburgh. 



Royal Society, June 18.— Prof. F. O. Bower, 

 president, in the chair.— F. Walker : The igneous 

 geology of the Dalmeny district. The igneous rocks 

 of the Dalmeny district may be divided into three 

 groups :— (i) Basaltic lavas of Dalmeny type which 

 are of undoubted Lower Carboniferous age. (2) A 



NO. 2804, VOL. I I 2] 



suite of sills which bear analcite and occasionally 

 some nepheline. These sills are probably to be 

 reckoned as the underground manifestation of Lower 

 Carboniferous volcanic activity. (3) A group of 

 quartz dolerite sills which belong to a later phase 

 of intrusion and appear to be connected with Permo- 

 Carboniferous earth movements. The second group 

 contains some interesting petrographical types includ- 

 ing teschenite, camptonite, and theralite! All three 

 types are represented in the Mons Hill sill, which is 

 of great complexity. — Miss Elizabeth Gilchrist : The 

 slow oxidation of phosphorus. Phosphorus glows in 

 air but not in oxygen at high pressures ; some gases 

 act as poisons while others act as promoters of the 

 glow. The reaction appears to take place in two 

 stages ; phosphorus trioxide being produced in the 

 first stage without glowing, and phosphorus pentoxide 

 in the second stage with glowing. The hindering 

 effect is ascribed to the production of an anticatalyst, 

 which probably consists of negatively charged 

 molecules. — G. A. Carse and D. Jack : On the X-ray 

 corpuscular emission from iron in a magnetised and 

 unmagnetised state. According to Ewing's theory 

 of magnetism there is something in the iron atom 

 that turns in response to an applied magnetic field. 

 Experiments on the X-ray corpuscular emission from 

 iron in a magnetised and unmagnetised state show 

 that in. the iron atom either the part that turns 

 does not emit an appreciable number of electrons 

 or the chance of ejection is not affected by the 

 orientation. — Lancelot Hogben : The mechanism of 

 amphibian colour response. The pituitary gland of 

 mammals, birds, reptiles, amphibia, and fishes con- 

 tains a substance which exercises a highly specific 

 effect upon the melanophores of amphibia, inducing 

 a condition of maximal expansion which is not 

 precisely simulated by other drugs or tissue extracts, 

 which agree in their action on plain muscle with 

 pituitrine. The action of pituitary extract on melano- 

 phores is local and direct. Like other pituitary 

 antacoids, the melanophore stimulant is destroyed 

 by trypsin. Like the oxytoxic principle, it is more 

 stable to acid hydrolysis than the pressor substance, 

 and is mainly located in the posterior lobe of the 

 fresh mammalian gland. After removal of the 

 pituitary (whole gland) in both adult frogs and 

 larval salamanders, the melanophores remain per- 

 manently in a state of maximal contraction, even 

 when the animals are exposed to optimum conditions 

 for producing pallor. When injected with pituitary 

 extracts they expand fully ; but the animals regain 

 pallor even under exposure to those conditions which 

 invariably produce melanophore expansion in normal 

 or partially hyopohysectomised animals. The evi- 

 dence for a direct nervous control of amphibian 

 colour response is inadequate. Pituitary secretion 

 fluctuates in correlation with conditions which evoke 

 pigmentary change. 



Sheffield. 

 Society of Glass Technology (Leeds meeting), 

 June 20. — W. E. S. Turner : Specifications in the 

 glass industry. Certain types of glass, such as that 

 used for optical purposes, are bought on specification 

 and must conform strictly to certain properties. In 

 the case of containers for liquids and solids, no 

 attempt is made to manufacture or purchase on the 

 basis of specification. If the glass industry insisted 

 on furnace material makers providing, for example, 

 refractories to specification, then the glass manu- 

 facturers themselves should at least show they are 

 prepared to supply their own goods to specification. 

 — Th. Teisen : Notes on the design of pot arches. 

 Modern types should contain good facilities for heat 

 distribution and control ; they should also combine 



