February 27, 1908J 



NA TURE 



407 



solid mattt-r as u reaches the bottom of the tank in which 

 it is settled by means of a conveyor belt. This process 

 was found by' repeated tests to give remarkable results 

 both in the completeness of the separation effected and in 

 the small proportion of liquid carried off by the solid 

 matter. — Two deterrents to the dissolution of free gold in 

 the cyanide process : Duncan Simpson. These deterrents 

 are oil and lime, and the author gave examples showing 

 their influence and the method adopted for counteracting 

 it. — .\ rapid method for the estimation of arsenic in ores : 

 H. E. Hooper. — The Indian mint assay of silver bullion : 

 F. T. C. Hugrhes. A description of the methods employed 

 in the Indian mints for the assay of the varying qualities 

 of bullion received for coinage purposes. This process has 

 been in vogue for upwards of fifty years, and has given 

 satisfactory results, being specially suited to the condition 

 of labour, &c., existing in India, and to the varied nature 

 of the bullion operated upon. 



Dublin. 

 Royal Dublin Society, January 21. — Prof. A. W. Conway 

 in the chair. — The lines of flow of water in saturated 

 soils, especially peat-mosses : L. F. Richardson. The 

 author shows by means of experiments on " Bog of Allen 

 peat that the general velocity with which the water passes 

 through the peat is proportional to the pressure gradient, 

 and by utilising this fact he deduces the differential equa- 

 tions for the flow of water through peat saturated witli 

 water, neglecting capillarity, and assuming the peat to be 

 isotropic in order to facilitate the mathematical treatment 

 of the problem. The differential equations are solved by 

 a freehand graphic method, and the form of the saturated 

 water surface determined, when the tubes of flow arc 

 somewhat horizontal. From the diagrams thus obtained it 

 is possible to calculate in a simple manner — the rainfall 

 being given — how far apart drains must be cut in a bog 

 so as to remove just the right amount of water, and con- 

 versely what will be the effect of a given cutting. The 

 paper concludes with the description of another method 

 for determining the conductivity of peat for water. — k 

 simple form of apparatus for observing the rate of absorp- 

 tion of oxygen by polluted waters and by other fermenting 

 liquids : Dr. W. E. Adeney. 



Edinburgh 

 Royal Society, February 3. — Prof. Andrew Gray, F.R.S.. 

 vice-president, in the chair. — Sensitive state induced 

 in magnetic materials by thermal treatment : J. G. 

 Gray and .X. D. Ross. When steel is cooled from a high 

 temperature, the first measured susceptibility in a given 

 field is much higher than later measured values after the 

 specimen has been subjected to cyclic magnetisations. This 

 phenomenon, first noticed by Ewing, was studied in detail 

 for steel, cast iron, cobalt, and soft iron. In soft iron 

 the phenomenon is absent or present only to a small degree. 

 In certain specimens of steel the effect was induced to a 

 slight degree when the substance was raised to as low a 

 temperature as 100° C. and then cooled ; it increased with 

 increased temperatures to about 700° C, but further in- 

 crease of temperature had little influence. Mechanical 

 vibrations considerably reduced the effect. The pheno- 

 menon was most marked in fields which gave large values 

 of the susceptibility, tending to zero as the saturation point 

 was approached. — The growth and development of the 

 limbs of the penguin : Dr. D. Waterston and A. C. 

 Geddes. The material had been brought home by Dr. 

 W. S. Bruce, leader of the Scottish Antarctic Expedition. 

 A comparison of the stages of development with the corre- 

 sponding stages of development of the chick of .a duck 

 showed that the limbs of the penguin began at a fairly 

 early stage to diverge in inode of growth from thos^ of 

 the duck, indicating that the adaptation of the fore-limbs 

 for swimming purposes did not implv a degeneration from 

 a form suitable for flight. 



P.VRIS. 



Academy of Sciences, Fi-l.ruary 17. — M. H. Becquerel 

 in tlie chair. — The properties of pure starch : L. 

 Maquenne. Referring to a note by M. Fouard at the 

 Inst meeting of the academy on the isolation of a new 



NO. 2000, VOL. 'J']'\ 



soluble form of starch, the author points out that this 

 soluble starch is in all respects identical with that described 

 by him, in conjunction with M. Roux, in the Comptes 

 rendus two years ago. The name amylose was given to 

 this soluble form of starch, and ordinary starch solution 

 consists of a clear solution of amylose thickened with 

 amylopectose. — Isotonic solutions and isoosmotic solutions : 

 V'ves Delagre. A continuation of the controversy with 

 J. Loeb. The author concludes that it is impossible to 

 doubt that the parthenogenesis of the eggs of the sea- 

 urchin can be brought about in solution isotonic with sea- 

 water. — The visibility of Saturn's ring on the side not 

 lighted by the sun, and its reappearance in January, igoS : 

 M. Ama'nn. A detailed account of the appearances pre- 

 sented by the ring between October 4, 1907, and January 

 14, 1908. — The relation between flying shadows and 

 scintillation : CI. Rozet. A definite relation has been 

 established between the shadow bands and the pheno- 

 menon of scintillation. The effects have been observed, 

 not only with the sun, but also with Venus, Jupiter, Mars, 

 and some stars of the first magnitude. — A theorem in the 

 theory of integral equations : E. Goursat. — The electro- 

 lysis of solutions of hydrochloric acid : E. Doumer. In 

 the electrolysis of hydrochloric acid, oxygen always 

 accompanies the chlorine, the proportion of oxygen to the 

 hydrogen set free at the other electrode depending on the 

 concentration, and increasing with the dilution of the acid. 

 With an anode of silver or mercury, capable of combining 

 with the chlorine, the proportion of oxygen for the same 

 intensity of current 'is increased. The author concludes 

 that the electrolysis of both the acid and the water takes 

 place simultaneously. The amount of oxygen produced is 

 not negligible, and must be taken into account in the 

 determination of the transport factor of the ions and in 

 the measurement of the conductivity of these solutions. — 

 Lithium in radio-active minerals : Mile. Gleditsch. 

 Determinations of the copper, lithium, and the radio- 

 activity compared with uraniuin have been m.ade for the 

 minerals thorite, Joachimsthal pitchblende, Colorado pitch- 

 blende, carnotite, chalcolite from Cornwall, and autunite. 

 Lithium was found in all these minerals in amounts vary- 

 ing from 0-00017 per cent, to 003 per cent., and copper 

 in all but autunite. These results prove that there^ is^ no 

 simple relation between the amounts of copper and lithium 

 in radio-active minerals. — A. new method of estimating 

 sulphur in organic substances : Isodore Bay. The sub- 

 stance is mixed with sodium carbonate and magnesia, and 

 ignited in a current of oxygen. Test analyses are given 

 showing the accuracy obtainable. — The separation _ of 

 chloride and iodide of silver : H. Baubigny. .\ solution 

 of ammonium carbonate can be used to effect the quanti- 

 tative separation of silver iodide and chloride in the absence 

 of bromide. — A method for the complete analysis of 

 vegetable materials : J. M. Albahary.— The hydrolysis of 

 perchloride of iron. The effect of the valency of the 

 nega'ive ions: G. Malfitano and L. iVIichel. — The 

 reciprocal displacement of hvdrocarbon groups in the 

 Friedel and Crafts reaction :'H. Duval.— The reducing 

 properties of organo-metallic compounds : M. Leteiiier. 

 By the action of ethyl-magnesium bromide upon ethyl 

 oxvpivalate, besides the glycol 



CH,(OH).C(CH,,),.C(OH)(C,H,0, 

 expected, the compound CH,(OH).C(CH,),.CH(OH).C,H, 

 was obtained as a by-product. This is formed by the 

 reduction of the ketone CH,(OH).C(CH,)„.CO.C,H„ 

 ethylene being evolved. Other instances of the reducmg 

 action of alkvl-magnesium compounds are cited. — The 

 simultaneous pVoduction of the i : 6- and 2 : 7-dimethyl- 

 anthracenes in the action of CH.Cl,, of CHCl,, or of 

 C„H,Br,, upon toluene in the presence of aluminium 

 chloride : James Lavoux.— The essence of Tefranthera 

 polyantha, var. citrata : Eug. Charabot and G. Laioue. 

 The essences from the bark, leaves, and fruits were 

 examined. That from the bark contained citral, citron- 

 ellal, and an alcohol, possibly geraniol ; the essence from 

 the leaves contained citral, cineol, and the same alcohol 

 ,as the bark : the essence from the fruits consisted of citral, 

 an ester, and possibly geraniol. — The possible presence of 

 microscopic diamonds on the sea floor and in a specimen 

 of vegetable earth : J. Thoulet. The mechanical analysis 



