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ietp FOUNDED 1903. TO pROMOTE THE STUDY OF ELECTROCHEMISTRY, ELECTROMETALLURGY, CHEMICAL PHYSICS, METALLBCRABHY AND KINDRED SweJEcTs. -___ ~ _ I_ _ _ _ _ _ _ _ ~ DECEMBER, 1914. ANNUAL GENERAL MEETING. The Annual General Meeting of the Faradajr Society was held on Monday, November 23, 1914, in the rooms of the Chemical Society, Burlington House, London, W. The President, Sir Robert Hadfield, F.R.S., was in the Chair. The minutes of the Annual General Meeting, 1913, were read and approved. The Chairman moved the adoption of the Report of the Council, and the Statement of Accounts and Balance Sheet for the' year ending December 31, 1913, as printed in the July number of the Proceedings. The motion was carried unanimously. The following OFFICERS and COUNCIL were elected to serve for the year 1914-15 :- Presided: Sir Robert Hadfield, F.R.S.Vice-Presidents : Professor K. Birkeland, Bertram Blount, W. R. Bous- field, ILC., Professor F. G. Donnan, F.R.S., Dr. Eugene Haanel, Professor A. K. Huntington, Dr. T. Martin Lowry, F.R.S. Treasurer: F. Mollwo Perkin, Ph.D. Council: R. Belfield, W. R. Cooper, Emil Hatschek, Dr. R. S. Hutton, Professor Alfred W. Porter, F.R.S., E. H. Rayner, A. Gordon Salarnon, Dr. R. Seligman, Dr. George Senter, Cav. Magg. E. Stassano. Mr. J. W. Hinchley and Dr. E. K. Rideal were re-elected Honorary Auditors. The Chairman then proposed a vote of thanks to the Institution of Electrical Engineers and to the Chemical Society, for granting the Society the use of their Lecture Theatres for the ordinary meetings. The motion was carried with acclamation.On the motion of the Chairman, votes of thanks were passed to the retiring Officers and Members of Council, to the Honorary Auditors, and to Mr. F. S. Spiers, the Secretary of the Society. This concluded the business of the meeting.2 PROCEEDINGS OF THE FARADAY SOCIETY SPECIAL GENERAL MEETING. A SPECIAL GENERAL MEETING was subsequently held for the purpose of considering the following alterations in the Rules recommended by the Council. The Rules as amended were unanimously adopted. A. RULE 111. (2).*-Add the following paragraph to this Rule :- Persons not residing in the United Kingdom may be accepted by the Council for election under the same conditions as members of the cognate Societies recognized by the Council under this Rule. B.RULE V. (I).+-Before the word “Vice-Presidents” add “ Not less than three nor more than seven.” C. RULE V. (3).f--Delete the following words : Two Vice-Presi- dents and three ordinary Members of the Council shall retire from office each year.” This Section a t present reads as follows :- “ A Candidate for election who is already a member of any one of certain cognate Societies, to be determined from time to time by the Council, may send in an applica- tion form signed by himself only, without being proposed by a Member.” t At present the Rule reads : “Seven Vice-presidents.” $ This Section at present reads as follows :- office each year. Secretary, shall hold office for niore than three successive years.” “ Two Vice-presidents and three ordinary Members of the Council shall retire from No Vice-president or ordinary Member of Council, excepting the PROCEEDINGS OF THE SEVENTY-FOURTH ORDINARY MEETING.GENERAL DISCUSSION ON 6 6 THE HARDENING O F METALS.” The Seventy-fourth Ordinary Meeting of the Faraday Society was held on Monday, November 23, 1914, in the rooms of the Chemical Society, Burlington House, London, W. The meeting took the form of a General Discussion on “The Hardening of Metals.” The President, Sir Robert Hadfleld, F.R.S., was in the Chair. The Chairman opened. the Discussion with a short introductory address. Referring to the history of the most important “ har- dened” metal in the world, namely steel, he said that the world’s future progress literally depended upon understanding correctly and in a scientific manner “The Hardening of Metals.” The accurate determination of the hardness of steel alloys was now being investigated by a special Research Committee of the Institu-PROCEEDINGS OF THE FARADAY SOCIETY 3 tioii of Mechanical Engineers.They were that night going to discuss the rationnZe rather than the practical applications of hardening. Having referred with deep regret to the great loss sustained by the science of. metallurgy in the death of Dr. Martens, in whose honour Osmond had invented the metallo- graphic term “ martensite,” he concluded by showing a specimen, probably the first to be exhibited in modern times, of an ancient piece of high carbon steel which had been hardened by quenching. I t was taken from beneath the stone pillar of Heliodsrus at Bes- nagar, India, and it contained 99.2 per cent.Fe, 0.70 per cent. C, 0.04 per cent. Si, 0.008 per cent. S, 0.20 per cent. P,o*02 per cent. &In, and traces of nickel and chromium. This specimen, perhaps more than two thousand years old, was the first example of ancient steel which he knew of that contained sufficient carbon to be called steel. Dr. GF. T. Beilby, F.R.S. (Glasgow), read a paper entitled “ Some Recent Papers on Hardening and Overstrain in Metals, and the Bearing of these on the Author’s Amorphous Theory of the Hardened State.” I. Hardening of a pure metal may be caused by cold working or by chilling. 11. Hardening of alloys, of mixtures of metals, or of .mixtures of metals and metalloids may be caused by cold working, by chilling, or by the mere adiiiixture of different kinds of molecules, either simple or compound.In Class I, if the amorphous-crystalline theory of the hard and soft states is accepted no further explanation is needed, but in view of the fact that this explanation is not yet universally accepted, the facts and conclnsions on which the theory is based are briefly discussed. The essential distinction between molecular aggregation in the two states is shown to consist in mutual constraint in the one staie and freedom of vibration in the other. The vibrational freedom of the molecules in the crystalline state is an essential and charac- teristic feature of that state and inevitably leads to potential mechanical instability. Mutual constraint of the molecules in the amorphous state inevitably leads to greater mechanical stability.Mutual encroachment into each other’s sphere of vibration enhances the mutual attraction of the encroaching molecules. This view falls in line with the ascertained facts as to the storage of energy in the hardened metal which is released on solution, the loss of elasticity evidenced by acoustical and other phenomena, and the electrical, magnetic, and optical phenomena which probably indicate interference with the freedom of the electrons as well as with the vibrational freedom of the molecule as a whole. Further, the mechanical instability of the crystalline state is shown by the ease with which the surface of even brittle, non-plastic, crystalline metals and other substances can be flowed into a smooth, hard, vitreous layer or skin.The steps in the recrystallization of the hardened metal as the temperature is raised to the point at which the whole mass is apportioned among fully developed crystalline grains supply further confirmation of the reality of the distinction between the two states. Class 11. The hardening of alloys and mixtures. If the amorphous- crystalline theory is accepted for Class I it must also be accepted for Class 12,4 PROCEEDINGS OF T H E FARADAY SOCIETY wherever the condition OF flow at internal surfaces can be shown to exist either as a result of cold working or from contraction strains due to chilling. In this class the x*iiorphous ‘or thermally metastable state may also be pro- duced by sudden solidification from the liquid state.Even when solidifica- tion is complete, during subsequent slow cooling molecular rearrangement among the different constituents or phases may occur, and these changes may make either for greater or less hardness of the aggregate in whole or in part. Mr. J. C. W. Humfrey (Sheffield) read a Paper on ‘(The Part Played by the Amorphous Phase in the Hardening of Steel.” The conclusions arrived at in the Paper may be summarizcd as follows :- The hard structure which can be produced in carbon steels by quenching and in certain alloy steels by normal cooling, is due to the presence of a hard amorphous solution of a iron and iron carbide, which solution may be compared to Beilby’s amorphous phase formed by overstrain. To explain the formation of this amorphous phase the author advances a theory that the passage of a substance from one allotropic modification to another of different crystalline form involves the temporary formation of an amorphous state, corresponding to the liquid phase of the modification about to be formed.In steels such a change occurs at Ar 3 ; and if, due to sudden cooling or to the presence of certain alloyed elements, the change-point is lowered to a temperature below that at which crystallization in the viscous mass becomes difficult, then the amorphous form will be retained in a metastable form in the cold. The theory is supported by evidence derived from the micro-structure and physical properties of carbon steels hardened by quenching, and of alloy steels which attain a hard structure even when slowly cooled.Professor C. A. Edwards (Manchester) read a Paper on (‘ The Hardening of Metals by Quenching.” Steels not being the only metals which can be hardened byquenching, must be regarded merely as the higher members of a group of alloys which undergo similar changes, namely, undergo decomposition at certain critical temperatures, during which evolutions of heat occur. The critical heat changes are probably a result of the quick cooling, for if this be increased the temperature at which the changes occur is lowered and their thermal magnitude decreased ; in other words, there is an increased tendency to prevent the inversion and keep the heat of the carbide change inside the cold material. Can the highest obtainable rates of cooling completely suppress the heat change ? The experiments of Benedicks point in this direction and lead to the view that hardening is caused by the suppression of the heat of the carbide inversion. It has been objected that the structures of quenched steels do not support this view, but Carpenter and the author consider these to be a result of the internal stresses set up and not to indicate a difference in physico-chemical constitution.Thus the hardness produced by quenching is brought about by crystal twinning and possibly direct slipping, and the resulting formation of amorphous layers. The author meets Rosenliaiii’s’objection that the stresses set up cause no serious flow or move- ment in the quenched steel. He points out that Hanriot has considerably increased the hardness of cylinders of silver by pressure alone without anyPROCEEDINGS OF THE FARADAY SOCIETY 5 apparent deformation. It is unnecessary to suppose with Humfrey that in passing from one allotropic form to another crystals pass through an amor- phous stage ; if so, where would the energy absorbed come from ? On the other hand, if twinning takes place, energy would be absorbed and stored up in the amorphous layers.The facts brought forward by Dr. Desch are con- sidered not to be opposed to the theory of hardening by twinning. Dr. Cecil H. Desch (Glasgow) presented a Paper on “The Hardness of Solid Solutions,” which was communicated by Dr. T. Martin Lowry, F.R.S. Any complete theory o€ hardening must take into account the in‘creased hardness which accoinpnnies the formation of solid solutions (mixed crystals). The hardness of the elements is closely proportional to the internal pressure, a/nz in van der Waals’ equation, and the hardness of solid solutions has been attributed to an increase in the internal pressure.Native copper has been shown by the X-ray method to have a simple cubic space lattice. Gold and silver are probably quite similar, and the atomic volumes of the two metals are almost identical. It is therefore difficult to see how any considerable distortion of the space lattice can occur when the two metals are alloyed. The density is unchanged by alloying, and the metals interpenetrate freely by diffusion, but the hardness is twice as great as that of the single metals. Transparent isomorphous mixtures of salts may be obtained without optical evidence of internal strain, and yet exhibit increased hardness.A great diff ercnce in the attractive forces between the atoms is not easily conceived in the simple case of silver and gold. No theory at present accounts satisfactorily for the facts. Dr. Desch also contributed a Note on ‘‘ Crystal Twinning and the Martensitic Structure.” The theory that the hardness of quenched steels and other alloys is due to repeated twinning is open to serious objections. It is shown that a twinned martensitic structure may be obtained in metals and alloys which are not hard. A very slowly cooled low-carbon steel, previously overheated, showed a characteristic martensitic structure in pearlite of the usual hardness. The hard constituents of quenched alloys may or inay not exhibit twinning, and the latter is at most an accompaniment, not a cause, of the hardness, Mr.Andrew McCance (Glasgow) contributed a Paper on “The Interstrain Theory of Hardening,” which was read in abstract by the Secretary. Only two real allotropic forms of iron exist-gamma iron, which can dissolve carbon and is non-magnetic, and alpha iron, which does not appre- ciably dissolve carbon and is magnetic at ordinary temperatures. ‘‘ Beta iron” is only alpha iron which has lost the property of ferromagnetism from purely thermal causes, and the pseudo-change-point at A 2 is due to a variation in the specific heat which always accompanies this transition. Gamma iron cannot be made ferromagnetic by any treatment such as permanent defor- mation, etc. Metals after deformation are best described as being in a condition of “ interstrain,” since there are facts which cannot be explained by the theoryof a hard amorphous vitreous phase, such as the dissimilarity in6 PROCEEDINGS OF THE FARADAY SOCIETfr magnetic properties of strained gamma and strained alpha iron and the hardening effect on metals of high fluid pressure without any resulting defor- mation.Hardening by deformation results from purely structural causes which affect the crystalline state. In steels during cooling two transformations can take place : (a) the change in the iron from gamma to alpha, and (b) the change in the state of solution of the carbon. Quenching supp-esses ( b ) but allows ( a ) to prozeed, and the alpha iron formed under this condition is interstrained and hard.This accounts for the magnetic properties of quenched steels and for the fact that the hardness reaches a maximum independent of the carbon content. Austenite, which is soft, results when both transformations are suppressed, but when tempered at about 250’ C., or immersed in liquid air, the transformation from gainma iron to alpha takes place suddenly and an increase in hardness corresponds with the formation of the interstrained alpha iron. Professor Henry M. Howe (Columbia University) contributed to the Discussion a Paper on “Hardening with and without Martensitization,” which was communicated by the President. Of the six methods of hardening according to the author’s classification, five are martensitizing and one non-martensitizing.The former ways of harden- ing are ( I ) that of carbon isteel by rapid cooling ; ( 2 ) that of steels with an intermediate proportion of manganese or nickel by air or other moderately slow cooling ; (3) that of Maurer’s austenitic manganese steel by cautious reheating ; (4) that of 25 per cent. nickel steel by liquid-air cooling ; (5) cold deformation of any ductile metal. The non-martensitizing way of hardening is holding manganiferous austenite (Hadfield’s manganese steel) shortly below the transformation range (e.g. at 550°), whether the cooling thence be fast or slow. I t is shown how all these methods of hardening but the last can be explained by the amorphous theory. This is described as referring the harden- ing to the presence of a very great proportion of iron made amorphous by the formation of innumerable slip bands, caused by the sudden expansion due to the starting of the y-a transformation at innumerable nuclei, and its arrest by the pressure thus caused. The martensitization which occurs in all these cases (formation of the very hard acicular constituent known as “ martensite ”) tallies with the conceptioii of innumerable slippings.The amorphous theory cannot explain the sixth method of hardening (if this also takes place in the absence of carbon-this is being tested), because at such high temperatures amorphous iron should be able to re-crystallize. The y theory, which ascribes hardness and brittleness to martensite because it is an undercooled solution of y in a, is shown to be unsatisfactory in all of the six cases.If hardening No. 6 takes place in the absence of carbon, the author considers the p (an alleged intermediate allotropic modification of iroil) more credible than the amorphous theory, in spite of the surprising slightness of the discontinuity in the cooling curves at the supposed P-. transformation-point. Dr. T. M. Lowry, F.R.S., and Mr. R. G. Parker presented a (‘ Note on Metallic Filings.” They suggested that these were probably cold-worked in an extreme degree. They regarded the remarkable properties of fresh filings of the silver-tin ‘(dental alloy” as due to the presence of a large proportion of Beilby’sPROCEEDINGS OF T H E FARADAY SOCIETY 7 amorphous phase. The change of density produced by "ageing" these filings at roo0C. is larger than in the case of pure metals, but experiments now in progress have shown that other metallic filings exhibit analogous changes of density when annealed at IOOO or even at 80°C.These tempera- tures are much below those given by Beilby for the annealing temperature of hard-worked alloys, and are very much below the annealing temperatures commonly used in metallurgical work. After the reading of the Papers the subject was thrown open for general discussion. Dr. J. E. Stead, F.R.S. (Middlesbrough), in a communication made by the President, stated that in his opinion we had not sufficient data on which to found any definite conclusion as to why steel is hardened by heating to above Ac 1-2-3 followed by quenching, but it was certain that the carbon was mainly responsible. The different behaviour of hardened and annealed steel when treated with chemical reagents proved that there was a difference in their chemical constitution. The allotropic theory could only be regarded as a tentative hypothesis. The solid solution hypothesis too might be one of several pointing in the right direction.The internal stress hypothesis also might be more or less correct, but it must not be forgotten that 0.9 per cent. carbon steel could never be made intensely hard merely by stressing and distorting in the cold. Again, iron saturated with 1.7 per cent. phosphorus, the phosphorus in this case being in solid solution Fe,P in iron, is difficult to drill, while Cleveland pig, or any grey iron containing even 2 per cent. or more phosphorus, in which case the Fe,P is in a free state, can be readily machined.Dr. Stead opposed the view that twinning was an indication of hardness, nor did he consider that martensite probably consisted of a mass of twin laminz. The same steel containing 0'9 per cent. carbon, whether quenched from 750" C. and barely martensitic or quenched from goo0 C. with a pro- nounced martensitic structure, is equally hard, in spite of the fact that the internal stresses in the second case must be much the greater. In conclusion, although we had not sufficient data on which to base dogmatic conclusions, there could be little doubt that on the carbon condition mainly depended the extreme hardness of steel. Mr. Andrew McCance in a written communication emphasized the difficulty of explaining the hardness produced without deformation by the action of high pressures on metals, and the magnetic properties of strained a and y iron, by Dr.Beilby's theory of the amorphous phase. Again, had it been shown experimentally that the amorphous state was actually harder than the crystalline for any substance at the same temperature? Mr. McCance also dwelt on the difficulty of correlating magnetic properties with the amorphous phase theory, and he criticized the way in which Mr. Humfrey met the difficulty by assuming that in the crystalline space lattice it was the molecules which were regularly spaced. Mr. Humfrey's view that structure- less martensite was formed when all the austenite had been transformed to amorphous a iron, while the more prominent structure obtained from a higher quenching temperature was due to the retention of much austenite, was not in accordance with experimental evidence.The President was pleased to notice that Dr. Stead emphasized the fact that the main factor in the question of the hardness of iron alloys was the presence of carbon. It was also evident that Professor Howe, who had8 PROCEEDINGS OF THE FARADAY SOCIETY kindly sent a communication all the way from America, was also coming back to a carbonistic theory. Sir Robert Hadfield felt so strongly on this matter that he had offered a Research Prize of A200 in order to stimulate the study of the carbides of iron and of iron alloys generally. Professor T. Turner (Birmingham) said that the subject under dis- cussion was of extreme importance.Sometimes we required a metal to be soft, and sometimes its value depended on its being hard ; we therefore want to know the reason why it is hard or not hard. He agreed with Dr. Beilby that we should know more of the niolecular structure of the metals. There were two kinds of hardness which should be kept distinct from each other in one’s mind. One was the hardness caused by mechanical deformation, and the other was the hardness brought about by a chemical change which produced a closer packing of the molecules of the material. Still it must be borne in mind that when a metal is hardened its density increases to only a very small extent. Another thing which altered molecular clibtance and produced hardness was the forination of solid solutions. There tnust be enormous forces brought into play when one substance dissolves another, and it is natural to assume that closer packing of the tnolecuks results.Professor Turner explained most of the changes in hardness which took place in various steels by the solution or the segregation of the various carbides at different temperatures. Dr. W. H. Hatfield (Sheffield) pointcd out that at least three of the theories brought forward that evening were really an indirect result of Beilby’s work on the amorphous theory. Dr. Hatfield had independently arrived at views similar to those of Mr. Humfrey. It seemed obvious that when y iron changes to a iron it passed through the mobile or amorphous phase ; but during quenching the amorphous phase was presumably side-tracked and remained unchanged, thus producing hardness. Dr.Hatfield pointed out objections to his and Mr. Humfrey’s views. Mr. T. G. Elliott (Sheffield) was glad to observe a revival of interest in carbon as a factor in the cause of hardness, and expressed the view that an examination of steels under heat treatment would throw great light on the subject. Dr. F. J. Brislee (Roby) asked Dr. Beilby whether the passage from the amorphous to the crystalline stage would have a definite transition-point, and whether, in tlie case of aluminium, this point was identical with the annealing-point. Mr. S. A. Main (Sheffield) pointed out that the various theories advanced that evening were qualitative rather than quantitative. What was badly wanted was a definite scientific unit in which to express hardness, especially extreme hardness. Sir T.Kirke Rose asked Professor Edwards about the production of twinning in tin by bending. “How long did he leave the tin before examination ? ” He asked this question because tin anneals itself at the ordinary temperature in 24 hours. The President, in reply, agreed with Mr. Main’s view that a definite scale of hardness, which was independent of any particular method of estimation, must be arrived at. He mentioned that when measured by the rebounding test quartz was the hardest material known. Many of the theories advanced that evening must be wrong, because they required that the projectile of a Is-in. gun, which weighed a ton and had a glass hard surface, was in a state of strain. This was improbable, as the projectile could cut through 15 in.of steel without being fractured. Professor C. A. Edwards, in reply to Sir T. K. Rose, said the twinningPROCEEDINGS OF THE FARADAY SOCIETY 9 in bent tin took place immediately, and could be observed under the niicro- scope by scratching the surface with a needle or making a pin-prick. Dr. G . T. Beilby, in reply to Dr. Hrislee, said that one might regard the annealing-point of aluminium as a definite transition-point between the amorphous phase and the crystalline phnse. At the conclusion of the meeting Mr. H. L. Heathcote (Coventry) exhibited some novel devices for testing the hardness of materials. One of these was a practical application of the old simple file test. The instrument consists of two files and a graduated arc.When a round article is placed in the angle between the two files and the upper arm is allowed to fall slowly the equilibrium position of the specimen will be a measure of its hardness. Another simple device shown was a modified, automatic centre- punch in which the hardened point was replaced by a ball-holder. In another method, useful for testing every part of the hardened surface, recourse was had to baths of a reagent (alcohol, nitric acid, and water) capable of developing latent chemical differences on the surface of the hardened steel article. Professor Ernst Cohen was to have read a Paper on “The Influence of Allotropy on the Metastability of Metals, and its bearing on Chemistry, Physics, and Technics,” but as at the last moment he was unable to come over from Utrecht, the reading of his Paper was postponed.Professor Cohen cabled his greetings to the meeting and said he hoped to visit the Society at a later date. OFFICIAL NOTICES. CHANGES ASHCROFT, E. A . . . . . . COLEMAK, H. S. . . . . FEILMANN, E. , . . . . . SAND, H. S. H. . . . . . . OF ADDRESS. The Cottage, Northweald, Essex. ;jS, Rlouiit Road, Warley, Langley, nr. Bir- 5, hlaytield Koxd, Acton, W. The Sir John Cass Technical Institute, Aldgate, mingham. E.C. THE HADFIELD RESEARCH PRIZE. A Research Prize of the value of jt;zoo has been placed by Sir Robert A. Hadfield, F.R.S., at the disposal of the Council of the Iron and Steel Institute, to be awarded by the Council to the author of the best con- tribution to the publications of the Institute on the subject of the Different Forms or Combinations of Carbon in Iron, Steel, and Alloys of Iron with other Elements.Competition for the Prize is open to metallurgists, chemists, and others interested in metallurgy, and it is proposed that tlie prize shall be awarded at the annual meeting of the Institute in May, 1916, for the best paper presented before February I, 1916. Sir Robert Hadfield is also prepared to offer a second prize for the paper next in merit to the one which gains the first prize, provided it is adjudged to be a really meritorious paper.10 PROCEEDINGS OF THE FARADAY SOCIETY It is not desired to limit the scope of the research too closely, but it is suggested that the work should be in continuation of, or based upon, the work of pre!ious investigators, such as Jullien, Abel Miiller, Ledebur, T.Sterry Hunt, Akerman, Arnold, E. D. Campbell, Hogg, Parry, and others. The object of the Research Prize is to stimulate the study of carbides in iron and iron alloys generally, also with a view to discovering the best method of determining the forms and combinations in which carbon occurs in iron and steel, including martensitic and austenitic steels. These carbides are now spoken of by metallurgists in a general way, as sub-carbides, carbides, or double carbides. It is very desirable to define the composition of these more accurately and to ascertain whether other carbides exist which have hitherto not been identified. The study of the molecular constitution of the carbides will also fall within the range of the investigation and, in this connection, attention may be directed to previous researches on particular combinations of carbon or forms of carbide. For instance, it would be of interest to determine whether the ordinary carbide is Fe,C, Fe6C,, or some other combination. If so, what is its nature and molecular constitution ? The foregoing is a general direction which should guide intending participants in this research. I t is hoped that the results obtained will throw much light on the cause of hardness of steel, also on the natiire and form of carbon combinations with iron and its alloys. Intending competitors should communicate, in the first place, with Mr. G. C. Lloyd, Secretary of the Iron and Steel Institute, 28, Victoria Street, London, S.W., from whom further information may be obtained. BINDING CASES. Dark green cloth gilt-lettered cases for binding any back volumes of the Transactions may be ordered by application to the Secretary, 82, Victoria Street, Westminster, S.W. If the separate parts and the title-page are sent post paid to MESSRS. UNWN BROTHERS, LTD., 27, Pilgrim Street, E.C., the cases will be supplied and the volumes bound complete for 2s. each, or 2s. 4d. post free for the United Kingdom. Price IS. zd. post free. TRANSACTIONS OF THE AMERICAN ELECTROCHEMICAL SOCIETY. Members who desire it can have the Transactions of the American Electrochemical Society bound in cloth instead of in paper on payment of an extra charge of two shillings a year, which should, be sent to the Secretary of the Fara,day Society, 28, Victoria Street, London, S.W.Gbe Breebam ere00 UNWIN BROTHERS, LIMITED WOKING AND LONDONGbe Breebam ere00 UNWIN BROTHERS, LIMITED WOKING AND LONDON

ISSN:0014-7672    

DOI:10.1039/TF91410BD001

出版商:RSC    

年代:1914

数据来源: RSC