;26 



NA TURE 



[March 28, 1895 



reiaarkable Specimens of Old Pemvian ' Are Plumaria,' " gives 

 a description of two veiy fine heed-dresses in Ancient Peruvian 

 feather wcik, which are illustrated by a beautifully executed 

 coloured plate. It is strange, as the author points out, "that 

 the sptcimens of old Peiuvian 'ars plumaria' unearthed from 

 the hundreds of huacas, excavated but too often by vandalic 

 treasure-seekers, have not attracted more attention." The best 

 specimens of feather-nosaic were made in the sixteeiith and 

 seventeenth centuries, and the ait has new practically died out. 

 —Mr. S. H. Ray al stiacis and annotates "Some Notes on the 

 Tannese," by Rev. W. Giay. Mr. Gray has been a missionary 

 in Tanna for twelve years, and so he can speak from adequate 

 personal knowledge; he gives infoincation on diess, circum- 

 cUion, political crgEnisalion, war, kava, religion, social 

 organisation and marriage, the calendar, the winds, and 

 language. This is a valuable supplement to Dr. Codrington's 

 monograph ; the section on religion is of especial value. Dr. 

 H. Ten Kate describes and illustrates a collection of ethno- 

 graphical oljecis ficm the Timor Group. The suppleiiient to 

 vol. vii. of the ArcUtv is an account of the Narg, or the Siamese 

 fhadow-figures in the Volkerkunde Museum in Berlin, by Dr. F. 

 W. K. Miiller. A transcripticnardlranslation (inGeiman)of the 

 rhymtsof the drama is given, which is a fragment of the Kama- 

 jana. It is illusltaled by eleven plaies, eight of which are 

 coloured. Vol. viii. ccn merces wilh the conclusion of Dr. Ten 

 Kate's paper, which is illustrated by four plates. This part is of 

 more geceral interest, as it deals partly with ihe religion and the 

 sacred an mals of the Timorese and other Indonesians ; the 

 author agrees wilh Pleyte, that the snake cult is indigenous to 

 Indonesia, ard is not bcircwed frcm India. There is a 

 useful little table of the distrilulion of certain objects. — S. K. 

 Kusnezow writes on the death-cult of the Tscheiemisse (a 

 Ural-Altaiic pet pie on the Volga, near Kazan). These 

 numbers of the Arihiv contain the usual valuable notes and 

 bibliography. 



SOCIETIES AND ACADEMIES. 



LO.NDON 



Royal Society, Jai;uaty 17.— "On Slow Changes in the 

 Magnetic Peimeabihty cf Iron." ■" 



By William M. Mordey. 

 The conclusions to which the observations lead, so far as 

 the y have gone, are : — 



(1) The effect is not fatigue of the iron caused directly by re- 

 peated mpgnetic reversals— it is not " progressive magnetic 



fatigue." ... . . 



(2) Neither magnetic nor electric action is necessary to its 

 production. . 



(3) It is a physical change resulting from long-continued 

 heating at a very moderate temperature. 



(4) It appears to be greater if pressure is applied during 

 beating. 



(5) It is not produced when the iron is not allowed to rise 

 more than a few degrees above the ordinary atmosphere. 



(6) It is similar to the efTect produced by hammering, 

 rolling, or by heating to redness and cooling quickly. 



(7) The iron returns to its original condition on re-annealing. 



(8) It does not return to its original condition if kept unused 

 and at ordinary atmospheric temperatures, whether the periods 

 of rest are short or long. ,, „ ,, 



March 7— "The Action of Heat upon Ethylene, II. Uy 

 Prof. Vivian B. Lewes. 



From the results of the experiments described in the paper it 

 is stated that :^ 



(1) The initial decomposition of ethylene by heat is very rapid, 

 and requires but a shoit flow through a heated containing vessel, 

 such primary decomposition, however, being but slowly com- 

 pleted, owing to secondary reactions, which lend to reform 

 elhylene. 



(2) Dilution has but little effect in retarding the decomposi- 

 tion of elhylene, unless it be very large. 



(3) Incicase in rate of flow diminishes the amount of dccom- 

 po»iti<n whin the heated area IS small, but rajiidly dimini>hes 

 ID efftcl as the length of flow through a heated area increa.ses. 



(4) The decomposition of ethylene is chu fly caused by radiant 

 heat, the efiect ol which is very great as compared with the de- 

 composition due to contact wiih heated surfaces. 



March 21. — "The Cause of Luminosity in the Flames of 

 Hydrocarbon Gases." By Prof. Vivian B. Lewes. 



NO. 1326. VOL. 51] 



The facts which appear lo be established in this paper are : — 



(1) That Ihe luminosity of hydrocarbon flames is principally 

 due to the localisation of the heat of formation of acetylene in 

 the carbon and h\drogen produced by its decomposition. 



(2) That such jocaiisation is produced by the rapHiiy of its 

 decomposition, which varies wilh the temperature of the flame 

 and the degree of dilution of the acetylene. 



(3) That the average temperature of the flame due to 

 combustion would not be sufficient 10 produce the incandescence 

 of the carbon particles within the flame. 



In a paper on the action of heat upon ethylene, broucht 

 before the Royal Society this spring, the author showed that 

 the decomposition of ethylene into acetylene and simpler 

 hydrocarbons was mainly due to the action of radiant heat, and 

 was but little retarded by dilution, whilst he ha^; shown in this 

 paper that the acetylene so produced requires a considerable 

 increase in temperature lo bring about its decomposition \\hen 

 diluted, and it is possible with these data to give a fairly 

 complete description of the actions which endow hydrocarbon 

 flames with the power of emitting light. 



When the hydrocarbon gas leaves the jet at which it is being 

 burnt, those portions which come in contact with the air are 

 consumed and form a wall of flame which surrounds the issuing 

 gas. The unburnt gas in its pa'sage' through the lower heated 

 area of the flame undergoes a number of chemical changes, 

 brought about by the action of ladiant heat emitted by the 

 flame walls, the principal of which is the conversion of the 

 hydrocarbons into acetylene, methane, and hydrogen. The 

 temperature of the flame quickly ri^es as the distance from the 

 jet increases, and a portion of the flame is soon reached at 

 which Ihe heat is sufTiciently intense lo decompose the acetylene 

 with a rapidity almost akin to detonation, and Ihe heat of its 

 formation, localised by the rapidity of its decomposition, raises 

 the liberated carbon particles to incandescence, this giving the 

 principal part of the luminosity of the flame ; whilst these 

 particles, healed by the combustion of the flame gases, still 

 continue to glow, until finally themselves consumed, this 

 external hcnling and final combustion adding slightly lo the 

 light emitted. 



Any unsaturated hydrocarbons which have escaped conversion 

 into acetylene betore luminosity commences, and also any 

 methane which may be present on passing into the higher 

 temperaluies of the luminous zone, become converted there into 

 acetylene, and at once bL-ing decomposed to carbon and 

 hydrogen, increase the area of the light-giving portion of the 

 flame. 



" On the Changes in Movement and Sens.ition produced by 

 Ilemisection of the Spinal Cord in the Cat." By C. D. 

 Marshall. 



"On the Analysis of Voluntary Muscular Movements by 

 certain new Instruments." By Dr. W. R. Jack. 



"On the Spark Spectrum of Argon as it appears in the 

 Spark Spectium of Air." By Prof. W. N. Hartley, F.R.S. 



Chemical Society, March 7. — Dr. Armstrong, President, 

 in the chair. — The following papers were read : — Dimethyl- 

 ketohexanuthylene, by F. S. Kipping. This substance is a 

 colourless oil boiling at 174-176°, and is prepared by dis- 

 tilling calcium oa'-dimethylpimelate with soda-lime. — The use 

 of barium ihiosulphate in standardising iodine solution, by 

 K. T. Plimpton and J. C. Chorley. Barium ihiosulphate, 

 BaSjOa, 11^0 is well .adapted for standardising iodine solution, 

 inasmuch as it keeps well, has a high molecular weight, and is 

 readily acted on by iodine. — The melling points of racemic 

 modifications and of optically active isomerides, by F. S. 

 Kipping and W. J. Pope. Dextro-rotatory and racemic 

 ir-monobromocamphor melt at the same lempeiaiure, and the 

 melting point of the one is not depressed by the presence of 

 the other isomeridc ; the same is true of the inactive and 

 dextro-rotatory irmonochlorocamphors. — Phenyl elhers of 

 methylene- and ethylene-glycols. Synthesis of a methyl- 

 butyrolaclone, by E. Haworih and W. H. Pcrkin, jun. A 

 numlier of phenyl ethers of methylene- and ethylene-glycol 

 have been obtained by the use of sodium jihenate ; aincthyl- 

 bulyrolactone has been synthesised from chvlic sndinnictliyl- 

 malonate.- Mctliylisobuiylacetic acid, ClI.Mc, CM.. ClIMe. 

 COOIl, by W. II Bcnilcy and M. W. Hurrows. This acid 

 was prepaicd by tin- distillation of methylisobuiylmalonic acid, 

 which in turn wa.s synthesised from elhylic sodiomcthyl- 

 malonate and isobulyl bromide. 



