Metallurgical Abstracts : general and non-ferrous, Vol. 2, Part 13

METALLURGICAL A B S T R A C T S

(G E N E R A L A N D N O N -F E R R O U S )

Volume 2 1935 Part 13

I — PROPERTIES OF METALS

(Continued from pp. 553-568.)

Refined Aluminium. R o b ert G adeau (Metallurgist (Suppt. to Engineer), 1936, 11, 94-96).—S um m ary o f a paper presented to th e Congrès In te r­

nationale des Mines, de la M étallurgie, e t de la Géologie Appliquée, Paris.

See Met. Abs., th is vol., pp. 365 and 497.—R . G.

_ On the Softening and Recrystallization of Pure Aluminium. --- (A lu ­ m inium , 1935, 17, 575-576).—A review o f recen t w ork of Calvet an d his collaborators ; see M et. A bs., th is vol., pp. 453, 454. A. R . P .

*Some Optical Observations on the Protective Films on Aluminium in Nitric, Chromic, and Sulphuric Acids. L. T ronstad and T. H bverstad (Trans. Faraday Soc., 1934, 30, 362-366).—The optical properties of n a tu ra l films on alum inium were measured in various solutions an d th e ir change w ith tim e of immersion observed. L ittle change occurs in such films in chrom ic acid solutions w ith or w ithout chloride ; th e films are n o t protective in concentrated sulphuric acid, and in concentrated nitric acid th e protective films are altern ately dissolved and re-formed. The m ean thickness o f n a tu ra l films on alum inium is 100 p. or more th a n 10 tim es as th ic k as those on iron.—A. R . P.

*Light from [Burning] Aluminium and Aluminium-Magnésium [Alloy], J . A. M. van L iem pt an d J . A. de V riend (Bee. trav. chim., 1935, 54, 239-244).

„ . — S. G.

’"Investigations Relating to Electrophotophoresis Exhibited by Antimony Gisela Isser and Alfred L ustig (Z . P hysik, 1935, 94, 760-769).—U ncharged submicroscopic particles subjected to an electric field in an intense beam of light are found to move eith er in th e direction of, or against, th e field. This is the phenomenon o f electrophotophoresis, which is here investigated in considerable detail for particles o f antim ony. E xperim ental results are n o t interpretable in term s of a th eo ry w hich considers th e particles to be surrounded by a cloud of ions.—J . S. G. T.

Plasticity of Bismuth Due to Occluded Gas. W . E. Berg (N ature, 19 3 4 ,133, 831).—Anomalous results obtained by Georgiefi an d Schmid (J. In st. Metals, 1926, 35, 461) and by Gough an d Cox (J. In st. Metals, 1932, 48, 227) relating to th e ductile properties of bism uth crystals are explained by assum ing th a t the crystals used by G. an d S. contained a certain am o u n t of th e gas used in cooling the crystals, w hich were prepared by th e Czochralski m ethod ; G. an d C. prepared their crystals b y th e B ridgm an m ethod. E xperim ents confirming the assum ption th a t th e co n ten t of gas is responsible for th e slipping of a suitably-oriented bism uth cry stal und er tension are briefly described.— J . T.

Plasticity of Bismuth. W . F . Berg an d L. Sandler. E . N . da C. A ndrade (Nature, 1935, 136, 915).— B. an d S. refer to discrepancies existing in th e literature relating to th e p lasticity o f b ism uth. A ndrade an d R oscoe’s m ethod has been used to grow bism uth crystals in vacuo in various gases. C rystals grown in vacuo showed behaviour a t variance w ith results obtained by A ndrade and Roscoe. Gas co n ten t of th e crystals appears to have little effect on th e plasticity. The hardness o f bism uth crystals prepared b y B ridgm an’s m ethod is probably another exam ple o f strain-hardening. A. replies, rem arking th a t

* Denotes a paper describing the results of original research, t Denotes a first-class critical review.

Z Z

he has been unsuccessful in conveying to B. th e significance of A. an d R .’s w ork

th e m am axis (a x) and parallel thereto (a2) ) 0 m _ l .r j _ 2-2 x 1 0 '5 W eerts gave th e following values between 26 an d 189 . . i

“ lI?iductlo»Xo l" V e r lio w T , m , e , a t a , « t o th e M agnstic M .th o d : S u p „ -

„„„snotivitv of Cadmium N. K iirti an d F . Sim on (N ature, 1934, 133, 9U7- 908f —P a rtic u la rs ^ f experim ents for the production of v ery l o w t e ^ a t u r e s by adiabatic diam agnetization of m anganese a m rn o m u m su lp h a te a n d o th e substances are briefly referred to . Cadm ium is found to be,come super conducting, w ith a tran sitio n tem p eratu re a t a b o u t 0 0 K . J.J

*Ma<rnetic Properties of Solutions of Cadmium in Molten Cadmium Chloride and of°Molten Calomel. J . F arq u h arso n an d E . H eym ann (Trans. Faraday Soc 1935 31 1004-1010).—Solutions of cadm ium in cadm ium chloride both

fn

^Properties of Sublimed Calcium. P a u l B astien (Com.pt. rend., 1934, 199, 577-579).— Cf. M et. Abs., th is vol. pp. 413, 497. The properties of calcium sublim ed by the C haudron-H erenguel process, cast und er argon, an d ol 99 3 % p u rity (Ca(s)) are com pared w ith those of tw o specimens of m d u s tn a l calcium of 98 6% p u rity (Ca(A)) and 93% (Ca(B)). The c o e ff o fe x p a n s io n b e tw e e n 20°-100° C was 25-2 x 1 0 '6. The hardness was Ca(s), 13; Oa(A), 14, a n a Ca(B) 26. ‘ The density a t 20° C. was 1-542 ± 0-005. The tensile stren g th s were : Ca(s), 4-4; Ca(A), 5-1; Ca(B), 2-8 kg./m rn.2; elastic lim its : Ca(s) 1-03- Ca(A) 2-2; Ca(B), v ery sm all; elongations: Oa(s), 5 3 /0 , oa(A), 30-50/ • Ca(B) very small. The sublim ed calcium was d raw n to a wire betw een 420° and 460° C .; its hardness was 17 an d elongation > 60% . T he losses in weio-ht in 1% alcoholic solution of hydrochloric acid were : E /(s), l i b ; Ca(A) 147; Ca(B), 120 m g./em .2. The m ore ra p id corrosion o f Ca(A) th a n Ca(B)’was due to th e fact th a t th e im purities in th e form er are chiefly silicon and iron not in solid solution, those of Ca(B) being chiefly calcium chloride and lime. The ra te of a tta c k of sublim ed calcium in hydrochloric, n itric, and sulphuric acids, m easured b y gas evolution for various dilutions of from 0-100% , is shown graphically.—J . H . W.

^Solubility of Oxygen in Solid Cobalt and the Upper Transformation Point of the Metal. A. U. Seybolt and C. H . M athewson (T rans. Am er. In s t. M m . Met. Eng., 1935, 117, 156-172).—See M et. A bs., th is vol., p. 555.— S. G.

* Plasticity of Copper in Torsion. V. D. K uznetzov an d V. A. Semenzov (Zhurnal Eksperimentalnoy i Teoreticheskoy F iziki (J . Exper. and Theoret.

Physics), 1935, 5, (4), 343-351).— [In R ussian.] The elastic lim it of poly­

crystalline copper in statio n ary torsion is proportional to th e applied torque, and the internal coeff. of friction r , calculated by tak in g into account th e elastic lim it and assuming th a t flow is caused n o t by th e to ta l effort applied b u t by the difference between th is and the elastic lim it, is a c o n sta n t a t all th e stresses investigated. A t 5° C. r\ = 1-4 X 1014 grm ./cm ./second. W ith a constant torsion m om ent a gradual strengthening ta k e s place a n d th e elastic lim it is increased.—N. A.

*The Heats of Adsorption of Hydrogen and Carbon Monoxide on Copper.

R alph A. Beebe (Trans. Faraday Soc., 1932, 28, 761-765).— A dsorption of carbon monoxide on copper granules is n o t uniform in its early stages, b u t

656 Metallurgical Abstracts VoL- 2

1935

I -— Properties o f Metals 657

^

^

f e Ti93Ti i5?nIfi7°L^nUrffr e Film °f C,°P,Per- M' L' Nichols (J - A ™ r . Chem.

boc., 1935, 57, 267-269).—I f copper and platinum plates joined by an external wire are immersed in copper sulphate solution the platinum gradually becomes 1 ai i, 0 ?°PPe r’ wbich g r o w s in thickness u n til it is thick enough to behave electrochem ically as th e massive m e ta l; a t the same tim e th e poten- n i« ei ’6f n mu-P m eS de™ e s from 0-2649 v. practically to zero (to 0-0056 v.

m 46 hr s.). ^ This film is 0-39 x 10'6 mm. thick, a value only h alf as great as thatfoundfor^the^surfacc film of copper by Oberbeck (A nn. Physik, 1887, [iii], F ^ h®c ° rner Metals of Electrical Distribution : Copper, Aluminium, and Lead.

Z : j * f r Z u } n ° CT i i rZ P’ 1933’ 15’ 55“ 5 9 ; discussion, 5 9 - 6 0 ) .- bee Met. Abs. (J . In st. Metals), 1933, 53, 338.— S. G.

A Correlation of the Tensile Strength and Electrical Conductivity of H ard- Drawn Copper Wire with Preferred Orientation.—I- III. R oy W ard D rier ( Wire and Wire Products, 1935, 10, 137-140, 183-190 230-235 2481 Gf J . M MM,.1930, 43, 402. A lte r brief W ™ to J e ' d Z e g ta antiquity m odern developm ents are reviewed w ith special reference to tech ­ nique in drawing copper wire. The grain-size of wire-bars has no influence on the quality of th e wire produced from them . V ertically cast bars give wire

° WCr ! n n strongth and higher conductivity and elongation th a n bars cast horizontally; these differences m ay be connected w ith variations in oxygen content. Suggestions have been m ade for elim inating th e casting reheating, and rolling of w ire-bars ; in a m ethod proposed by K ohlhaas now in the experim ental stage, copper is tap p ed from the furnace "into grooves in a A6 S°T MS sn°pr“ fi t Pla te ' W ire draw n from a rod so produced fulfilled all

', specifications, an d th is procedure prom ises great results. N orm al W c tr g ! f >m r heated bar? is now so standardized as to lead to few defects.

cklmg and continuous and single-block w ire-drawing through cast iron steel ungsten or tan talu m carbide, an d diam ond dies are briefly rev iew ed ’ The’

“S S

fi-r* *j x-“ys “d

correlated w ith electrical conductivity an d tensile strength. Increase in dness and tensile stren g th by cold-draw ing are due n o t only to th e effects nrobahlf-rircsc P f f eBCe £u t also to u n it cel1 orientation and to th e Cold rfraT nv r e of a Phase+“ th e " p h o u s (crystal fragm ental) condition, core n ftli I causes a debm tf ty p e of preferred orientation of u n it cells in the against ontTm,6 m r u f an d 100 planes are in Positions which m ilitate

2 deform ation D eform ation by shear occurs most

deform;™ f I 0 f easiest sllP are a t 45° to the direction of the S t a S r t f to dHW 5®i ° T ° f th e COTe ° f h a rd ' draw n wires causes d e n s e l v 7 r y i TOm ‘C °P tlm unl a n d > since it places th e m ost ako rediSw t l 5°“ *“ Plane® dlrect across th e p a th of electronic drift, it higher electrical COnductlvltV. W ires draw n entirely in one direction have a dram rn h conductivity th a n sim ilar wires in which th e direction of drawing has been reversed although th e tensile stren g th is the same. R efer­

ences are given to th e literatu re.—A. R . P.

O bservations on the R are E arth s.—X LIII. I.— The Atomic W eight of Europium The Specific Gravity of Europium Chloride. E . L. Meyers w ith

P / Chem- Soc., 1935, 57, 241-243).—The atom ic w eight of europium is found to be 152-30 ± 0-018. L. A. 0 .

and0APhCa ‘?«0nS tanu 0fiR h eTium and GaUium for W ave-Lengths X = 589 m u the oniTca 1 Pa“ + ’ ,H e rb e rt f an8e (Z - P hVsik > 1935, 94, 6 5 0 -6 5 4 ).-V alu es of r h e n i E i r f S’ refractive index, absorption an d reflection coeffs. of rhenium (surfaces tre a te d w ith em ery, filed, an d polished w ith chalk) an d

658 Metallurgical Abstracts

gallium for wave-lengths 589 mu an d 436 mu are given. V alues o b tain ed for

“ ♦Note on th e Failure oi a ^ i h e ' f e i li r c o fT g o ld safety

is form ed w hich offers little resistance to "oxidrition, an d finally th e fo ld link becomes dxsm tegrated an d

r.

and corrosion-resistance, are re n e w e d w ith K i S S r e d u c e d and others. Fatigue failures are m terg ra n u lar : th e fatigue M m reducea considerably b y increase of tem p eratu re an d b y corrosion. The creep ra te m arkedly affected b y sm all am ounts of im purities an d b y p recip itatio n effects caused by h eat treatm en t. T h e l a r g e r t h e grain-size, th e less is th e tendency

to

creep A bnorm ally large grain-size is n o t th o u g h t to p lay an y im Po rta n t Pa^

in failures of lead. Short-tim e corrosion te s ts are condem ned an d teste> of a t least 3 m onths’ d u ratio n are required to judge th e q u a lity o f lead, hopper, silver, an d nickel increase, w hilst antim ony an d b ism u th decrease, corrosion- resistance.—H . W . G. H .

♦Making and Testing Single Crystals of Lead. B. B. B e tty (Proc. d.mer. Soc.

Test. M a t , 1935, 35, (II), 193-200 ; discussion, 201-203).— See M et. A bs., th is

vol., p. 333.— S. G. _ , T e

♦Note on the Effect of Interrupted Straining on the Elongation of Lead. J. U C haston (J. In st. M etals, 1935, 57, 109-114; discussion, 1 1 4 r - 1 1 9 ) ,- I tT O found th a t by in terru p tin g a tensile te s t on com m ercially pure lead a t intervals, durin» which th e specimen is allowed to re s t for a sh o rt tim e free from stress, abnorm ally high values of elongation are produced. These m ay be as m uch as 5 tim es those obtained in a norm al tensile te s t. The influence on th e e ongation of th e d u ratio n of th e re s t period, th e ra te of straining, th e a m o u n t of elongation betw een successive re st periods, an d th e grain-size were stu d ied b y te s ts on extruded cable-sheath sam ples. A bnorm al elongations are n o t produced by in terru p ted straining on “ hardened ” lead alloys a t room tem p eratu re, b u t it is suggested th a t such effects m ay be obtained in these an d a n y o th er m etals a n d alloys if th e y are te ste d above th e ir recrystallization tem p eratu res, th e observations recorded m ay th u s have a bearing in connection w ith high- tem p eratu re m etallurgical research.— J . C. C.

♦Plasticity of Lead by Slipping. V. D . K uznetzov (Zhurnal PFspenmewtoinoy i Teoreticheskoy F iz ik i(J . Exper. and Theoret. P hysics), 1935, 5, (2), 192-201).—

[In Russian.] The plasticity of lead a t room tem p eratu res was stu d ied by the m ethod of double slip. I t cannot be calculated, as in th e case of liquid bodies, from th e eoeff. of internal friction, even if th e elastic lim it is ta k e n in to account.

W ith a static flow of lead, the shear stress is co n stan t a n d independent of the velocity. The shear stress is a characteristic of plasticity.—N . A.

On the Development of Longitudinal Cracks in Cable-Sheathing and Other Cable Defects not Hitherto Described in the Literature. O tto H aehnel {Teleg.

u. Fernsprech-Tech., 1935, 24, 179-182).—A detailed consideration of cable- sheath failures w hich are due to fau lts in m anufacture. L o n g itu d in al cracks frequently appear in th e seam of th e sh eath (Pressnaht), w hich is generally present in comm ercial practice. N o difference is found betw een th e behaviour of different grades of lead, b u t lead hardened b y alloying is less prone to longitudinal cracking. The observed phenom ena are discussed a n d causes and rem edies suggested.—C. E . H .

1935

I .— Properties o f Metals 659

Dependence of Magnetic Induction on the Magnetic Field in Superconducting Lead. G. N. R jabinin an d L. W. Shubnikow (Nature, 1934, 134, 286-287).—

Superconductivity is destroyed by a m agnetic field, th e critical field H k depending on tem perature. In th e vicinity of H k a sudden change occurs in the induction, B , w ith increasing as well as decreasing field-strength. This does n o t agree w ith th e form er concept o f a superconductor, in which, when th e field strength is decreased, the induction should be m aintained co n stan t by induced persistent currents. A t H = 0 the persistent currents give rise to a residuary magnetic m om ent in a superconductor.—J . S. G. T.

Magnetic Induction in a Superconducting Lead Crystal. G. N. R jabinin and L. W. Shubnikow (Nature, 1935,1 3 5 ,109).—Magnetic hysteresis exhibited by lead single crystals a t 4-24° K . is referred to . D estruction of supercon­

ductivity occurs in alm ost th e sam e w ay in single crystals as in polycrystalline lead. The appearance of superconductivity is found to be different for single crystals an d polycrystalline rods. All states o f a superconductor w ith an induction differing from zero are considered to be unstable. R esults confirm the concept o f tw o phases, a n o rdinary an d a superconducting phase w ith an induction equal to zero ; tran sitio n from th e superconducting to th e ordinary phase occurs rapidly, w hereas th e reverse tran sitio n ta k e s place more slowly.

—J . S. G. T.

*The Superconductivity of Thin Metallic Films [Lead]. A. D. Misener and J . O. Wilhelm (Trans. Roy. Soc. Canada, 1935, [iii], 29, (Sect. I l l ) , 5-11).—

In a n investigation o f th e superconductivity of th in films of tin (Met. Abs., th is vol., p. 277) i t was found th a t th e tran sitio n tem p eratu re was a function of th e film thickness an d th a t there was ap p aren tly a lower lim it o f thickness below which th e films were n o t superconducting. R esults obtained w ith th in films of lead now confirm th e results found w ith tin , so th a t these la tte r results are n o t associated w ith th e know n existence o f a non-superconducting allotrope of tin . Lead films show a rap id decrease of th e tran sitio n tem p eratu re as th e thickness is decreased below 9 x 10"5 cm. As in th e case of tin films, th e effect of current stren g th on th e tran sitio n tem p eratu re is n o t in accordance w ith Silsbee’s hypothesis.— J . S. G. T.

*The Atomic Weights of Several Radiogenic Leads. G regory P . B ax ter and Chester M. A lter (J. Am er. Chem. Soc., 1935, 57,467—L71).—The atom ic w eight of uranium lead is found to be a t least as low as 206-00 an d does n o t v ary system atically w ith the age of the m ineral source. The atom ic w eight of lead from various sources is investigated an d is found to be betw een 205-93 (the lowest value) an d 207-21 (the highest value).—L. A. O.

*The Rate of Solution of Magnesium in Acids. M artin K ilp atrick an d J . H enry R ushton (J. Physical Chem., 1934, 38, 269-306).— R ates o f solution of magnesium in aqueous solutions of hydrochloric, perchloric, benzene-sulphonic, sulphuric, acetic, chloracetic, dichloracetic, formic, glycollic, citric, ta rta ric , and mixed acids were determ ined. The reaction ra te s are com pared w ith those for zinc. The results can be in terp re ted in term s o f a modified diffusion theory taking into account th e w ater reaction.— J . S. G. T.

♦Photoelectric Properties of Pure and Gas-Contaminated Magnesium. R . J . Cashman and W . S. H uxford (Phys. Rev., 1935, [ii], 48, 734-741).—See M et.

Abs., th is vol., p. 557.— J . S. G. T.

♦The Wiedemann-Franz Number of ^-Manganese at — 190° C. H . Redde- m ann (A nn. P hysik, 1935, [v], 22, 28-30).— S. G.

♦The Surface Tension of Mercury in a Silica Apparatus. R . S. B urdon (Trans. Faraday Soc., 1932, 28, 866-876).—A value of 488 dynes/cm . was found in vacuo an d for a freshly form ed drop in air. This value decreases alm ost linearly up to 230° C. by 0-23 d y n e /0 C. The effect of gas adsorption on the surface tension o f m ercury is discussed.—A. R . P.

660 Metallurgical A bstracts

*The Thickness of Adsorbed Films on Mercury. H . Cassel (Trans. Faraday 8oo., 1932,28,177-179).—The surface density o fcarb o n tetracU O Tideadsor e on m ercury a t 11° C. corresponds w ith a m onom olecular film w hen th e h rs t layer is satu rated . A dsorption follows H e n ry ’s law over a wide rang ^ ^

*The Photochemical Reaction of Mercury with Oxygen.

Physicochimica U .S .S .S ., 1935, 1, 8 3 3 - 8 5 4 ) .- [ I n G erm an ] The> t a c t i o n between m ercury and oxygen, excited by th e i n c i d e n c e of short-w ave rad iatio n , is investigated, an d the mechanism of th e reaction is discussed —J . b. G. 1.

* Absorption of Hydrogen by Nickel. J . S m ittenberg (N ature, 1934, 133, 872).— Between 200° an d 650° C. there is no appreciable ad sorption o f hydrogen by nickel, b u t an appreciable absorption (homogeneous solution) occurs, t h e am ount of absorbed hydrogen a t a co n stan t tem p eratu re is pro p o rtio n al to the square ro o t of th e pressure’; a t co n stan t pressure th e dependence of th e absorption, a, on tem perature, T , is given b y log a = A - B J T . The h e a t of absorption, calculated from th is isobar, is a little less th a n — 3 k. cal./grm .m ol.

of hydrogen.—J . S. G. T. .

*A Magnetic Effect on Pirani Gauges using Nickel Wires. E dw in McMillan (Nature, 1934,133, 831-832).—The anom alous behaviour of a P ira m gauge to r th e m easurem ent of low pressures, an d p robably a ttrib u ta b le to th e existence of a tem perature gradient betw een th e centre an d ends of th e w ires, an d being associated perhaps w ith a change o f th e Thom son coeff. o f th e w ires, produced by a m agnetic field due to a n electrom agnet n ear th e gauge, is briefly referred

to .—J . S. G. T. „ „ . _ .

* Gyromagnetic Effect for a Ferromagnetic Substance above Its Curie Point [Nickel]. W. Sucksm ith (Nature, 1934, 134, 936).—M easurem ents of the gyrom agnetic effect, g, in th e case of 3 alloys of nickel an d copper containing ab o u t 56-5% nickel an d having respective Curie p o in ts a t — 14° C., — 9 I C., an d — 2° C., indicate th a t th e value o f g is 2-0 w ithin experim ental error. This indicates th a t th e param agnetism of nickel is due to spin alone.— J . S. G. T.

♦Ferromagnetic Transformation and Catalytic Activity [Nickel]. J. A rvid H edvall, R . H edin, an d O .P ersson (Z .physikal. Chern., 1934, [B], 27,196-208).

— Cf. Met. Abs., 1934,1, 548. The c ata ly tic influence of nickel on th e reaction N 20 = N 2 + O is shown to undergo a sudden change in th e neighbourhood of th e Curie point.—J . S. G. T.

♦On Palladium-Hydrogen. W illiam K rause an d Louis K ahlenberg (Trans.

Electrochem. Soc., 1935, 68, 449-469; discussion, 469-470).— See M et. Abs., th is vol., p. 499.—S. G.

♦Properties of the Platinum Metals. I.—Strength and Annealing Char­

acteristics of Platinum, Palladium, and Several of Their Commercial Alloys.

E . M. Wise and J . T. E ash (Trans. Am er. In st. M in . M et. E ng., 1935, 117, 313-324; discussion, 324-328).—See M et. A bs., th is vol., p. 140.— S. G.

♦The Kinetics of Heat Adsorption of Oxygen on Platinum. E . B. M axted a n d N. J . H assid (Trans. Faraday Soc., 1933, 29, 698-702).—The h e a t of adsorption of oxygen on p latin u m black rem ains c o n sta n t u n til th e ra te of adsorption becomes v ery sm all. A t th e beginning of ad sorption th e adsorption concentration depends on th e oxygen pressure, b u t in th e la te r stages i t varies as lctn, where t is th e tim e and k an d n are constants.—A. R . P .

♦The Adsorption of Oxygen and Hydrogen on Massive Platinum. H ans R eischauer (Z . physikal. Chem., 1934, [B], 26, 399-112 ; C. A bs., 1935, 29, 21).

—Between 20° an d 700° C. an d below pressures o f 0-05 m m ., hydrogen is n o t appreciably adsorbed on platinum . W ith oxygen th ere is little ad so rp tio n a t room tem perature. A dsorption begins a t 120° C. w hile a t 250° C. i t is com ­ p lete in a few m inutes. F u rth e r increase in tem p eratu re h as no effect u n til 400° C. is reached, w hen adsorption begins again. These tw o kinds o f ad so rp ­ tio n correspond to different heats of activation. The fractio n of th e p latin u m

1935

I . — Properties o f Metals 661

surface th a t is covered depends on the previous treatm en t of the m etal, b u t the to ta l am ount of oxygen adsorbed is constant and is ab o u t 5 layers thick.

The rate of adsorption is nearly independent of pressure. This is explained by assuming th a t p a rt of the platinum surface is composed of active atom s th a t aid the adsorption. A very high ra te is observed for freshly outgassed platinum in the process w ith the lower heat of activation, b u t after several experim ents the rate decreases. The oxygen adsorbed a t th e higher ra te is very reactive w ith hydrogen, b u t w hether th e active platinum atom s in this case are identical w ith the ones referred to above cannot be decided.—S. G.

Kinetics of the Reaction Between Carbon Dioxide and Hydrogen on Platinum from the Standpoint of the Adsorption Theory of Catalysis. M. Temkin and E.

Michailova (Acta Physicochimica U .R .S .S ., 1935, 2, 9-32).— [In English.]

Previous results relating to catalysis of the reaction C 0 2 -f H 2 = CO + H 20 are considered to have been v itia te d owing to th e presence of catalytic poisons.

Sources of poisoning being rem oved, th e reaction rate agrees w ith th e equation dpCo/dt = klV sJ ( k 2pai + p Co). The reaction ra te is determ ined prim arily by the rate of evaporation of carbon monoxide from the surface.— J . S. G. T.

♦Heterogeneous-Homogeneous Catalysis. H, + 0 2 in the Presence of Platinum. M. W. Poljakow , P . M. S tadnik, an d A. T. E lkenbard (Acta Physicochimica U .R .8 .S ., 1935, 1, 817-820).— [In German.] The mechanism of the catalysis o f th e reaction H 2 + 0 2 = H 20 2 by platinum is investigated.

—J . S. G. T.

♦The Atomic Weight of Rubidium. E . H . A rchibald, J . G ilbert Hooley, and N orm an W. E. Phillips (Trans. Roy. Soc. Canada, 1935, [iii], 29, (Sect. I l l ) , 155-162).—A value of 85-482 is found, chem ically; th is is som ew hat higher th a n the accepted value, 85-44 J . S. G. T.

♦Anomalous Diamagnetism of Selenium. S. S. D h arm ati (Nature, 1934,134, 497).—The diam agnetism of selenium is found to increase as th e fineness of powdering is increased and a t a certain stage the substance becomes p a ra ­ m agnetic, the param agnetic value increasing on fu rth er powdering of the substance. Colloidal selenium is m ore param agnetic th a n any of th e powdered samples. The param agnetism persists w hen th e powdered samples are washed w ith absolute alcohol.—J . S. G. T.

♦Photoelectric Effect in a Film of Silver Deposited on Nickel. N. FedenefE (Physikal. Z . Sowjetunion, 1935, 7, 58-65).— [In French.] I t is shown experi­

m entally th a t th e energy o f emission of photo-electrons em itted from a film of silver deposited on nickel increases initially w ith increase of thickness of the silver film, a tta in s its m axim um value a t a thickness corresponding approxi­

m ately to a monom olecular layer, an d th ereafter to the value corresponding to silver J . S. G. T.

[Electrical] Conductivity of Tellurium. C. H . C artw right and M. H aberfeld (Nature, 1934,134, 287-288).—The decrease o f electrical resistance of tellurium due to th e addition o f bism uth, copper, or antim ony is illustrated. The addition of 0-2% antim ony or bism uth caused th e electrical conductivity of tellurium to increase ab o u t 100-fold an d th e tem p eratu re coeff. of resistance to change from a negative to a positive value. A double role is a ttrib u te d to th e foreign atom s : th e y (1) provide free electrons an d (2) scatter electron waves.

—J . S. G. T.

♦Vapour Pressure Curve of Thallium at Very Small Vapour Densities. F.

Müller (Helv. Phys. Acta, 1934, 7, 491—492 ; Brit. Chem. Abs., 1935, [A], 438).—

Cf. Met. Abs., th is vol., p. 560. Values betw een 350° an d 500° C. are deduced from the absolute in ten sity o f absorption of th e 3776 A. thallium line in the vapour.—S. G.

♦The Transformation of ß-Tin into the a-Modification. M. M. C hertok (Zhurnal Tehnicheskoy F izik i (J. Tech. Physics), 1935, 5, (4), 711-717).-—[In Russian.] The transform ation of ß- into a-tin is influenced by tem perature,

6 6 2

Metallurgical Abstracts

grain-size, an d p u rity . The autom atic form ation of a-phase nuciei occurs also I t tem peratures as high as - 20° C. P lastic deform ation of (3-tin a t - 2 0 and - 30° C. considerably accelerates th e form ation of a. In some cases very rapid form ation of continuous fields of «-tin is possible (spontaneous transform ation).

*The Linear Velocity of Transformation of White Tin into Grey. A. K om ar a n d B. Lasarew (Physikal. Z. Sowjetunion, 1935, 7, 468-473).— [In English.]

The linear velocity of transform ation of w hite in to grey tin w as investigated in th in single crystals in th e range 18° to 80° C. The dependence of th e tr a n s ­ form ation on supercooling was determ ined. Velocities a b o u t 200 tim es greater th a n an y h ith erto m easured were found. To explain these large velocities, factors other th a n pressure m ust be ta k e n into account.—J . fc>. G. I .

♦Magnetism of Tin. S. R am ach an d ra R ao (N ature, 1 9 34,134, 288). W hite tin has a sm all param agnetic susceptibility equal to 0-025 X 10 6; grey tin is strongly diam agnetic, its susceptibility being 0-35 X 10 6. The susceptibility of colloidal w hite tin becomes diam agnetic as th e particle size decreases, th e susceptibility attain in g larger values w ith decrease o f particle size. On melting an d recrystallizing, th e w hite tin again becomes param agnetic, i n e param agnetic susceptibility of w hite tin is n o t a n atom ic p ro p e rty b u t depends

on cry stal stru c tu re — J . S. G. T.

♦Magneto-Caloric Effect in Superconducting Tin. K . M endelssohn an d J . K.

Moore (Nature, 1934, 133, 413).—The ad iab atic m agnetization an d dem ag­

netization of superconducting tin were exam ined. A cooling effect accom ­ panied m ag n etizatio n ; dem agnetization was accom panied b y heating, an d th is heating was alw ays greater th a n th e corresponding cooling owing to th e occurrence of heating due to eddy currents in b o th cases. The cooling effect observed a t th e various tem p eratu res were as follows : a t 3-3° K ., 0-05° ; a t 3-0° K ., 0-11°; a t 2-7° K ., 0-21°; a t 2-5° K ., 0-33°.—J . S. G. T.

*Superconductivity of Films of Tin. E. F . B u rto n (Nature, 1934,1 3 3 ,459).

E m ploying d.c., it is found th a t th in films of tin cease to show superconduc­

tiv ity when th e films are them selves p lated over w ith a film o f a non-super- conducting m etal, e.g. copper or nickel. As th e film of tin increases in thickness, a thickness is reached a t w hich th e superconducting p ro p e rty o f th e tin film is n o t lost b y surface platin g .— J . S. G. T.

♦The Effect of Magnetic Fields on the Superconductivity of Thin Films of Tin.

A. D . Misener, H . G rayson Sm ith, an d J . O. W ilhelm (Trans. Roy. Soc. Canada, 1935, [iii], 29, (Sect. I l l ) , 13-21).—The critical m agnetic field necessary to in te rru p t th e superconducting sta te of tin is found to be considerably greater for th in films th a n for th e m assive m etal. G reater tran sv erse fields are required th a n longitudinal fields. The tra n sitio n from su perconductivity to norm al resistance is com paratively g radual for th e films, an d m ark ed hysteresis is found. The critical m agnetic field a t a definite tem p eratu re is decreased by increasing th e c u rren t th ro u g h th e film ; th is is ap p a re n tly a tru e current- effect.—J . S. G. T.

The Apparent Thermionic Constant, A , of Clean Metals [Tungsten, Tantalum, Molybdenum]. A. L . R eim ann (Nature, 1934, 133, 833).—T he ap p aren t therm ionic co n stan t, A , of some clean m etals, e.g. tu n g sten , ta n ta lu m , an d m olybdenum , is definitely less th a n th e theoretical u p p er lim it for th is q u a n tity A . This defect is a ttrib u te d to th e v ariatio n w ith tem p e ra tu re o f th e effectively - free electrons per u n it volum e o f th e m etal. V alues o f th e difference so cal­

culated for these three m etals are of th e correct ord er o f m agnitude.— J . T.

Refraction of Slow Electrons by Sublimed Tungsten. W . I. K assatotschkin (Acta Physicochimica U .R .S .S ., 1935, 2, 317-336) [In G erm an.] I t is shown, inter alia, th a t th e value o f th e in te rn a l p o te n tia l o f tu n g s te n is 10-5 f 2 v.

The experim ental results can be b ro u g h t into agreem ent w ith those obtained b y R upp and Sproull w ith single crystals if it be assum ed t h a t refractio n of

1935

I . — Properties o f Metals 663

the electrons occurs w ithin a lay er o f unoriented m icrocrystals coating th e surface of th e single crystals.—J . S. G. T.

♦Velocity of Decomposition of Ammonia by Thoriated Tungsten. I. M otschan, I. Perevesensefi, an d S. R oginsky (Acta Physicochimica U .R .8 .S ., 1935, 2, 203-210).— [In German.] The presence of thorium is found to be w ithout appreciable effect on th e cataly tic decomposition o f am m onia a t a tungsten surface. The m echanism of the decom position is discussed.—J . S. G. T.

♦Embrittlement of Uranium by Small Amounts of Aluminium and Iron.

H. W. H ighriter an d W. C. Lilliendahl (Trans. Amer. In st. M in . Met. Eng., 1935, 117, 381-385; discussion, 385-386).—See M et. Abs., th is vol., p. 459.

—S. G.

♦The Preparation of Pure Finely-Powdered Vanadium. T heodor D ôring and Johannes Geiler (Z. anorg. Chem., 1934, 221, 56-62).—The production of extrem ely pure, finely pow dered vanadium by th e reduction of vanadium trichloride by hydrogen a t 900° C. is described. The m ethod was originally employed by Roscoe, an d yields a p roduct exceeding in p u rity th a t obtained by reduction of th e oxide by hydrogen a t ab o u t 1300° C. or by carbon, a lu ­ minium, or “ M ischm etall.”— J . S. G. T.

♦A Study of the Action of Acids on Zinc at Pressures of from One to Thirty Thousand Atmospheres. Thos. C. P o u lter an d Glen E . F razer (J. Physical Chem., 1934,38,1131-1140).—The velocity of th e reaction Z n - f H 2S 0 4-> Z n S 0 4 + H 2 is found to be affected very little by pressures up to 8000 atm . Between th a t pressure an d 30,000 atm . very little reaction occurs. A n electric cell having zinc an d hydrogen electrodes has its po larity reversed by a pressure sufficient to form ice V I. A t a pressure of 8900 atm . a t 20° C. in the presence of platinized platinum th e reaction 4H 2 + H 2S 0 4 -> H 2S + H 20 is predom inant so long as a hydrogen concentration rem ains.—J . S. G. T.

♦Superconductivity and the Hall Effect [Zinc]. B. Lasarew (N ature, 1934, 134,139)— Results obtained w ith single crystals of zinc show th a t zinc belongs to the group o f superconductors which are superconducting in one p articu lar crystallographic direction only, an d indicate th a t zinc strongly supports the rule for superconductors proposed by L. (P hysikal. Z . Sowjetunion, 1933, 4, 567). J . S. G. T.

Remarkable Optical Properties of the Alkali Metals. R . de L. K ronig (Nature, 1934,133, 211-212).—K . advances a n explanation of W ood’s results relating to th e reflecting powers o f th e alkali m etals (M et. Abs. (J. In st. Metals), 1933, 53, 339) differing som ew hat from th a t advanced by Zener (Nature, 1933, 132, 968).—J . S. G. T.

Problems of Super-Rare and Dispersed Elements. D . I. Shtsherbakov (Eedkie Metalli (Rare Metals), 1935, (3), 28-38).— [In R ussian.] A review of the properties, occurrence, an d application (actual as well as potential) in scientific and technical spheres of beryllium , rubidium , cæsium, tellurium , gallium, indium , germ anium , selenium , th alh u m , ta n ta lu m , hafnium , niobium , rhenium, and rare e a rth elem ents.—D. N . S.

■[Internal Stresses [in Metals]. Charles S. B a rre tt (M etals and Alloys, 1934, 5, 131-135, 154-159, 170-174, 196-198, 224-226).— Of th e m any m ethods proposed for determ ining th e in ten sity a n d d istrib u tio n of in tern al stresses in m etals only Sachs’ boring-out m ethod for rods an d tu b es a n d D awidenkow ’s split tongue and ring m ethod for tu b es are n o t dependent on unlikely assum p­

tions ; for the determ ination of plane stress d istrib u tio n M ather’s m ethod of making strain-gauge m easurem ents aro u n d a drilled hole gives satisfactory results. The Laue m ethod has serious lim itations since i t does n o t give quantitative results, an d even q u alitativ e results are unreliable since it confuses elastic strains w ith th e com plex lattice m ovem ents produced by plastic flow ; when th e la tte r has been appreciable th e results are entirely u n tru stw o rth y . The radial widening of lines in pow der diffraction p a tte rn s is related to micro-

664

s c o d i cin tern al stresses, b u t the relation betw een w id th of lines, ty p e of deform a­

tion, and am ount of deform ation is still obscure. C r y s t a l B h a ^ e m a lines while recrystallization an d grain-grow th ren d er th em sp o tty . J h e relative in ten sity of diffraction in th e different orders is altered b y plastic deform ation even w ith m etals th a t do n o t show strain-w idening of diffraction lines ; th is is a ttrib u te d to changes in th e electron d istrib u tio n in th e Reformed c ry s ta ls ; th e absolute in ten sity of diffraction is changed v e ry h ttie by elastic stresses in m etals. The large am ount of research w hich has been devoted to season-cracking of brass has revealed m any w ays of avoiding th e trouble, but so far no exact relation betw een stress in ten sity or d istrib u tio n an d tendency to crack has been established. A bibliography of 118 references lsin ciu d ed .

Strength o£ Metal Single Crystals. R . Roscoe (N ature, 1934, 133, 9 12.)-—

The condition of th e surface exercises a surprisingly large effect on th e in itial tensile stren g th of cadm ium single crystals. W hen th e crystals are grown in th e presence of oxygen, there is a m arked increase m th e resistance to shear.

N itrogen, carbon dioxide, an d w ater v apour produce no such effect, w hich is therefore a ttrib u te d to a surface film of o x id e ; th e effect can n o t be a ttrib u te d to an y strength of th e oxide film. I t is suggested th a t th e ideal m etal lattice has very little or no s tre n g th ; surface films can p rev en t in itia tio n of slip.

J . O. (jr. ± .

*An Investigation oi the Nature oi Creep under Stresses Produced by Pure Flexure. H. J . Tapsell an d A. E . Johnson (J . In st. M etals, 1935, 57, 1^1 137 , discussion, 137-140).—D eals w ith th e results obtain ed in a stu d y o f th e stresses an d strain s arising w hen a m aterial is subjected to bending m om ents m con­

ditions which produce creep. F o r experim ental reasons, i t was necessary to use a m aterial which w ould creep a t a ir tem p eratu re, a n d for th is reason lead of comm ercial p u rity was chosen. A p p aratu s was co n stru cted b y tvm en a beam of lead was subjected to uniform bending m om ent, an d m easurem ents of th e creep of th e beam were recorded. The whole equipm ent was housed in a cham ber m aintained a t co n stan t tem p eratu re. Tensile creep te s ts on th e m aterial of th e beam were also carried o u t a t co n stan t tem p eratu re in order to provide stress—stra in d a ta for th e calculation of th e stresses in th e beam . The investigation led to th e following conclusions : (1) in th e case o f a lead beam creeping und er stresses produced b y pure flexure, plane sections continue to rem ain p la n e ; (2) the red istrib u tio n of stress arising from creep is com plete w ithin hr. a fte r application of a bending m om ent, an d th e stresses continue unaltered w ith tim e ; (3) th e behaviour of th e beam u n d er flexure m ay be fairly com puted solely from th e relations betw een tensile stress an d ra te of strain corresponding to an y period of tensile creep testin g on th e m a te ria l o f th e beam .—H . J . T.

♦Practical Strength. A. V. S tepanov (Zhurnal Tehnicheskoy F izik i (J.

Tech. Physics), 1935, 5, (2), 349-361).— [In R ussian.] T he stre n g th of crystals and the factors governing ru p tu re depend m ainly on changes bro u g h t ab o u t in th e crystal by plastic deform ation.—N . A.

Physical Foundations of the Mathematical Theory of the Plasticity of Metals.

N. A. A rtem iev (Zhurnal Eksperimentalnoi i Teoreticheskoi F izik i (J . Exper. and Theoret. Physics), 1935, 5, 563-584).— [In R ussian.] Review a n d criticism .

—N . A.

Apparent Increase of the Plasticity of Metals in Plastic Torsion with Change of Sign. V. D. K uznetzov (Zhurnal Eksperimentalnoi i Teoreticheskoi F izik i (J . Exper. and Theoret. Physics), 1935, 5, 550-555).— [In R ussian.] A n e x p lan a­

tio n o f a phenom enon previously observed by K . (M et. A bs., th is vol., p. 207).

—N . A.

Crystal Plasticity. E . Orowan (Schweiz. A rchiv angew. W iss. Tech., 1935, 1, 117-126).— Cf. M et. Abs., 1934, 1, 481. A description an d analysis of

1935 I . — P r o p e r tie s o f M e ta ls

665

various aspects of the plasticity of crystals. I t is stated th a t the physical relation between tension an d deform ation which, up to th e present, has been im plicitly understood in th e usual conception of the plastic properties of crystals is non-existent. As for viscous liquids, the tension determ ines the rapidity of deform ation. Accordingly, a great num ber o f th e results of experiments to d ate lose th eir value from th e physical p o in t of view and m ust be subjected to stric t scrutiny. This them e is developed along purely specula­

tive lines.—W. A. C. N.

A Theory of the Plastic State in Metals. J . R . F u llard (Engineer, 1935,160, 138-139).—P lasticity is considered from th e p o in t of view of surface tension phenomena.—R . Gr.

Non-Ferrous Metals in Relation to Prolonged Stress. --- (Met. Ind.

(Lond.), 1935, 47, (10), 223-227 ; an d (sum m ary) Light Metals Research, 1935, 4, 86-88).—A review, w ith a bibliography, of creep tests on non-ferrous m etals and alloys. The w ork of A ndrade is specially emphasized. The m ajority of creep tests have been perform ed und er co n stan t load ra th e r th a n under constant stress, and the in terp re tatio n of results obtained by different m ethods is considered, especially in th e case of K ennedy’s w ork on certain light alloys.

—P . M. C. R.

The Piobert Effect in Iron and Soft Steel E ric W. F ell (J. Iron Steel Inst., 1935,132, 75-91; discussion, 92-97).—The P iobert effect is th e name given to the perm anent surface d istortion w hich accom panies th e sudden yielding of a polished bar of soft steel under increasing tensile stress. A sim ilar effect is recorded in the case of certain non-ferrous m etals. The effect appears to be associated w ith aggregates of sim ilar crystals ; its spread is progressive, and appears a t nearly constant stress. An analysis o f progressive distortion reveals some analogy w ith the d istortion of a single crystal. A . N adai, in corre­

spondence, refers to th e possibility of producing sim ilar effects in non-ferrous metals and in paraffin wax, and suggests th a t observations on loose m aterials (e.g. sand) throw light on th e m echanism of th e process.—P . M. C. R.

The Theoretical Strength of Materials and Their Practical W eakness. (Sir) William Bragg (J. and Trans. Soc. Eng., 1935, 26, (2), 27—41).—See Met. .46.s., this vol., p. 142.—P . M. C. R .

Properties of Metals a t Low Tem peratures. V. A. Sm irnov an d A. S.

F al’kevich (Khimstroi, 1934, 6, 548-551).— [In R ussian.] Cf. M et. Abs., this vol., p. 93. The discussion is continued.—S. G.

An Investigation of the Properties of Welded Metals a t Low Temperatures.

V. A. Smirnov an d A. S. F a l’kevich (Avtogennoe Delo (Autogenous Practice), 1935, (4), 3-12).— [In R ussian.] A review, w ith some results of w ork on the subject.—N. A.

tGases in Metals. C. A. E dw ards (Trans. Am er. Inst. M in . M et. Eng., 1935, 117, 13-38).—In s titu te of M etals D ivision L ecture, 1935. R ecent w ork on adsorption of gases by m olten m etals is review ed an d m odern knowledge of the subject is sum m arized w ith especial reference to adsorption of hydrogen in pickling and electrodeposition, to absorption of oxygen by m olten silver and copper and of hydrogen by copper, an d to th e adsorpt ion o f gases by steel.

—A. R . P.

^Diffusion of Gases Through Metals. C. J . Sm ithells an d C. E . R ansley (Nature, 1934, 134, 814).—The ra te o f diffusion, D, of hydrogen thro u g h copper, nickel, iron, and m olybdenum , an d of nitrogen thro u g h m olybdenum is found to be related to th e pressure, P, by th e equation D = K (a b P \/P )l (1 + aP).—J . S. G. T.

The Interaction of Gases w ith Solids. H . W . Melville (Nature, 1935, 136, 899-900).—W ork referred to a t th e discussion held b y th e Chemical Society, on Nov. 21, 1935, on th e in teractio n of gases w ith solids is briefly discussed.

Roberts’s work on tu n g sten (M et. A bs., th is vol., p. 560) proves th a t chemi-

6 6 6 M e ta llu r g ic a l A b s tr a c ts ^{Vo l. 2} sorption of hydrogen on tu n g sten proceeds w ith a very sm all energy o f a c tiv a ­ tio n - th is is in m arked co n trast to th e considerable energy o f activ atio n observed for metallic powders. Surface m igration can be studied by Bos- w o rth ’s m ethod (Proc. Roy. Soc., 1935, [A], 150, 58). The m echam sm of th e diffusion of gases through solids an d th e use of deuterium for investigating the m echanism of chemical reactions are briefly referred to .— J . S. G. 1.

♦Desorption oi Gases from Sooted Metallic Surfaces in a V acuum . H . B ehne and H . L öhner (A nn. P hysik, 1935, [v], 22, 92-96).— S. G.

♦The Activation of Gases by Metals. Louis K ahlenberg, N eal J . Johnson, a n d A lfred W . Downes (J. Amer. Chem. Soc., 1934, 56, 2218-2221). M etals exposed to a ir g ath er on th e ir surfaces d u st particles, m icro-organism s, an d adsorbed sulphur compounds. Consequently, w hen th e m etals are h eated m hydrogen, nitrogen, helium , argon, carbon dioxide, or oxygen th ere results a gas containing carbon com pounds an d hydrogen sulphide a n d having a b u rn t nitrogenous odour. H ydrogen passed over h eated m etals, therefore, gives tests for hydrogen sulphide, reduces perm anganate, ferric salts, an d blue starch iodide paper. H ydrogen passed over pure h o t silver can n o t be distinguished from ordinary pu re hydrogen b y chem ical or spectroscopic m ethods. E v en m om entary contact of th e silver w ith th e a ir or w ith a glass ro d renders i t im pure through adsorption of sulphur compounds. A sm all p roportion of th e hydrogen released from cathodically hydrogenated palladium a n d nickel reduces sulphur above 65° C.—S. G.

♦Theory of A nomalous Specific H eats. L. L an d au (P hysikal. Z . Sowjetunion, 1935, 8,113-118).— [In G erman.] M a n y solids are characterized b y a n increase o f th e ir specific h e a t w ith tem p eratu re u p to a c ertain critical tem perature, followed b y a subsequent sudden decrease. A m ath em atical th eo ry of th is phenom enon is developed along lines based on th e w ork of D ehlinger.— J . T.

-[Theoretically Interesting Aspects of H igh-Pressure Phenom ena. P . W.

B ridgm an (Rev. Modern Physics, 1935, 7, 1-94).—T heoretical aspects of high- pressure phenom ena are com prehensively reviewed. T he subjects discussed include : atom ic changes u nder p re s su re ; volum e changes an d th e law of force; th erm al expansion an d en tro p y a t infinite p re s su re ; periodic relations ; com pressibility of single c ry s ta ls ; tw o-phase e q u ilib riu m ; irreversible tra n s i­

tions ; d isco n tin u ities; electrical re s ista n c e ; th e rm a l conduction ; viscosity ; conditions of ru p tu re . A bibliography of 287 references is appended.—J . T.

Fifth Report of the Committee on Atomic W eights of the Intern atio n al Union of Chemistry. G. P. B ax ter, O. H önigschm id, P . L ebeau, an d R . J . M eyer (J . Amer. Chem. Soc., 1935, 57, 787-794).—See M et. A bs., 1935, 2, 416.— L. A. 0 .

The Identity of F erm i’s Reactions of E lem ent 93 w ith E lem ent 91. A. V.

Grosse an d M. S. Agruss (J. Am er. Chem. Soc., 1935, 57, 438-439).— Chemical tests show th a t th e elem ents obtained b y P erm i b y bom b ard m en t o f uranium w ith neutrons are n o t isotopes of elem ent 91 since th e y are n o t co-precipitated w ith zirconium phosphate, a n d th e y do n o t ap p ear to be elem ent 93 since th e y are n o t soluble in alkaline m edia. T heir id e n tity is, therefore, still in doubt.—A. R . P.

The Chemical Properties of Elem ents 93 and 94. A. V. Grosse (J . Amer.

Chem. Soc., 1935, 57, 440-441).— The probable properties o f these elem ents (if th e y exist) are deduced from considerations based on th e ir position in the periodic tab le.—A. R . P .

♦Fluorescence of Salts Surface-Activated by Condensed Metals. A. Terenin a n d F . Clement (Acta Physicochimica U .R .S .S ., 1935, 1, (6), 941-960).— [In E nglish.] A brig h t visible fluorescence is o b tain ed from alkali halide salts u n d er th e action of u ltra-v io let light w hen one of th e m etals calcium , thallium , lead, bism uth, or cadm ium is condensed, in vacuo, u p o n th em . N o sim ilar fluorescence is produced w hen sodium v ap o u r is condensed on th e alkali halides or on silver chloride, silver iodide, or cuprous chloride.— J . S. G. T.

1935

I . — Properties o f Metals 667

»Measurement oi the Frequency of Longitudinal Vibration of Non-Magnetic Rods. T. F . W all (N ature, 1 9 34,133, 139).—A rod o f copper, brass, or D u ra­

lumin, loaded a t its bottom end, is suspended w ithin and connected in series w ith a solenoid th ro u g h which a cu rren t flow’s. A search coil surrounds the central p a rt of the solenoid an d is connected w ith an oscillograph. The rod is set into longitudinal vib ratio n b y a ta p , an d variations o f e.m.f. in th e search coil due thereto are recorded on th e oscillogram. F rom th e period of these variations the value of Y oung’s modulus of th e ro d can be deduced. T h a t for brass is found to be 16-3 X 106lb ./in .2; th a t of D uralum in is 9-9 X 106 lb ./in .2.

—J . S. G. T.

The Metallic State. --- (Nature, 1935, 136, 115).—A brief rep o rt of a discussion on th is subject, held a t B ristol in J u ly , 1935. J . A . P rins discussed the absorption an d emission of X -rays by m etals. The absorption spectrum in crystals has a fine stru ctu re depending, in its general features, only on the structure and n o t on th e atom ic constitution of the crystal. H . W. B . Skinner showed how the stu d y of emission bands in th e u ltra-so ft region can given in ­ form ation ab o u t the occupied electron states in m etals. W . L. Bragg reported the form ation of a superstructure in copper-gold alloys. J . D. Bernal discussed the factors determ ining cry stal stru ctu res of alloys, pointing o u t th a t atom ic radii have often a decisive influence. H . M ark reviewed recen t theories of electrical co n d u ctiv ity ; J . A . P rin s reported w ork on am orphous antim ony.

A discussion on th e properties of bism uth was held. I t was suggested th a t hism uth possesses a m icrocrystalline superstructure of th e kind postulated by Zw icky; a n altern ativ e w ave-m echanical theory was suggested. W ork carried out a t M unich on th e electrical resistance of nickel an d its alloys was reported by W. Gerlach. A discussion on superconductivity was opened by J . M . Casimir. The cause o f th e phenom enon is still obscure. The opinion was expressed th a t all theories o f superconductors an d non-superconductors are wrong below 4° K . The possibility of utilizing nuclear spin to reach still lower tem peratures was discussed b y F . Sim on an d E. Teller.— J . S. G. T.

Sommerfeld’s Theory of Metals.—I. K . F . Niessen (Nederland. Tijdschr.

Natuurkunde, 1935, 2, 7 1 -8 9 ; C. Abs., 1935, 29, 7788).—A review on different phases of th e new er conceptions o f th e conduct o f electrons in m etals. S. G.

Surface Waves in the Electron Theory of Metals. A.-W. Maue (Z . Physik, 1935, 94, 717-741).—Cf. M et. Abs., th is vol., pp. 94, 279. W aves composed of metallic electrons can be propagated along m etal surfaces. The theory of such propagation in developed, an d th e contribution o f these waves to m etallic conduction is discussed.—J . S. G. T.

*A Magnetic Study of the Metallic State and the Fermi-Dirac Statistics.

Simon Freed an d H a rry G. Thode (Nature, 1934, 134, 774-775).—P articulars are given of m easurem ents o f th e susceptibility o f sodium (m etal) an d of sodium in solution, in liquid am m onia. The results are briefly discussed in connection w ith Bloch’s theory (J. In st. Metals, 1929, 41, 428).—J . S. G. T.

On the Thermal Conductivity of Metals and Some Methods for Its Deter­

mination. E. G. Shvidkovski (Zavodskaia Laboratoria (W orks' Lab.), 1935, 4, 1067-1078).— [In R ussian.] A review.—D. N . S.

Interpretation of the Benedicks Effect. L o th a r N ordheim (Nature, 1934, 133, 100-101).—An in terp re tatio n is advanced of the Benedicks effect, i.e. the existence o f therm oelectric forces in a homogeneous substance in which th e gradient of tem p eratu re is asym m etrically d istrib u ted , based on th e assum ption th a t the g radient is so high th a t considerable variatio n of tem p eratu re occurs in a distance w hich is sh o rt com pared w ith th e m ean free p a th of th e electrons.

“ Back diffusion ” o f electrons p a st th e discontinuity is neglected. The value of th e calculated e.m .f. is o f th e sam e order of m agnitude as ordinary th erm o ­ electric potentials.—J . S. G. T.

668 Metallurgical Abstracts

tThermionie Electron Emission and Adsorption. J . A. Becker (Rev. Modern Physics, 1935, 7, 95-128).—Theories and experim ental w ork relating to th e rm ­ ionic electron emission an d adsorption are com prehensively reviewed. J . T.

Theory of Some Photoelectric and Photomagnetoelectric Phenomena in Semi-Conductors. J . F renkel (Physilcal. Z . Sowjetunion, 1935, 8, 185-203).

[In English.] A theory of th e D em ber effect an d of th e K ikoin-N oskov effect in solid sem i-conductors, e.g. selenium , is developed.— J . S. G. T.

* Changes in Resistance of Liquid Metals in a Magnetic Field. I. K ikoin and I. F akidov (Zhurnal Eksperimentalnoi i Teoreticheskoi F izik i (J . E xp er. and Theoret. Physics), 1935, 5, 710-711).—[In R ussian.] The dependence o f the alteratio n in th e electrical resistance o f pure potassium a t 100° C. on th e in ten sity of the m agnetic field is determ ined. Above a definite field tension, A r— varies linearly w ith th e in ten sity of th e magnetic' field.—-N. A.

*The Change of the Resistance of Liciuid Metals in a Magnetic Field. Ib rah im F ak id o v an d I. K ikoin (Physilcal. Z . Sowjetunion, 1935, 7, 507-508).— [In English.] F o r the liquid alloy K N a it has been show n th a t th e relativ e change of its electrical resistance, AR /R , in a m agnetic field, H, is given b y A R /R = aH -j- b, for values of H above a critical value of 500 o erstedt. A sim ilar law holds for m olten potassium for fields above th e critical value o f 3600 oerstedt.

—J . S. G. T.

Energetic and Magnetic Anisotropy in Polycrystalline Ferromagnetic Plates in a Magnetic Field. A. Drigo (Nuovo cimento, 1934,11,345-356).— A th e o re ti­

cal discussion.— S. G.

*The Theory of the Dispersion of Magnetic Permeability in Ferromagnetic Bodies. L. L andau an d E . L ifshitz (Physikal. Z . Sowjetunion, 1935, 8, 153- 169).— [In English.] The d istrib u tio n of m agnetic m om ents in a ferrom agnetic cry stal is investigated m athem atically. Such crystals are show n to consist of elem entary layers m agnetized to sa tu ra tio n ; th e w id th of th e layers is d e te r­

m ined. I n a n ex tern al m agnetic field th e boundaries betw een th e layers m o v e;

th e velocity of m ovem ent is determ ined. E xpressions are derived for th e m agnetic perm eability in periodic fields, respectively p arallel an d perpendicular to th e axis o f easiest m agnetization.— J . S. G. T.

The Elementary Theory of Galvanomagnetic Phenomena in Crystals. J.

Frenkel an d T. K ontorow a (Physikal. Z. Sowjetunion, 1935, 7, 452-463).— [In English.] G alvanom agnetic phenom ena in d iv alen t m etals w ith cubic sym ­ m etry are discussed in term s of th e action o f electric an d m agnetic fields on th e individual charges. The results are in ex act agreem ent w ith those o f the m uch more com plicated theories of B lochinzew and N ordheim for th e H all effect, an d th e resistance change in a transverse m agnetic field. A n expression is derived for th e change of resistance in a parallel m agnetic field, an d th is gives a coefficient which is in accord w ith th e q u ad ratic law for w eak an d m oderate field-strengths.—J . S. G. T.

fGyromagnetic and Electron-Inertia Effects. S. J . B a rn e tt (Rev. Modern Physics, 1935, 7, 129-166).—Theories o f th e gyrom agnetic- a n d electron- in ertia effects are com prehensively reviewed. The subjects discussed include : a historical an d general discussion o f th e phenom ena ; th e m agnet as a gyro­

s ta t ; m agnetization b y r o ta tio n ; ro ta tio n b y m a g n e tiz a tio n ; gyroscopic m agnetization by ro ta tin g fields ; th e experim ents of Nichols an d of Lebedew ; Tolm an and S tew art’s w o rk ; the experim ents of Tolm an, K arrer, an d G uern­

sey, an d of Tolm an an d M ott-S m ith ; B a rn e tt’s w ork.—J . S. G. T.

Magnetic Properties and Nuclear Magnetic Moments. J . D orfm an (Physikal.

Z. Sowjetunion, 1935, 7, 126-127) [In English.] The possibility o f th e d e te r­

m ination of values of th e nuclear m agnetic m om ents o f ato m s from m easure­

m ents of m agnetic susceptibilities a t liquid helium tem p eratu res is briefly discussed.—J . S. G. T.

1935

I . — Properties o f Metals 669

Superconduction. R . Schachenm eier. A. P ap ap etro u (Z. Physik, 1935, 94, 812-815).—Polem ical, principally as to priority.—J . G. S. T.

Production of Heat in Superconductors by Alternating Currents. Heinz London (Nature, 1934, 133, 497-498).—A theory of h eat production by a.c.

is given which should enable one to ascertain w hether th e norm al electrons in a superconductor change th e ir general properties a t th e tran sitio n point. If normal conduction electrons exist in th e superconductor, a production of heat characteristic of each superconductor is to be anticipated.—J . S. G. T.

^Persistent Currents in Superconductors. K . Mendelssohn and J . D. B ab b itt (Nature, 1934, 133, 459-460).—Experim ents are described which m ake it appear certain th a t the effective m agnetic perm eability of substances decreases when they become superconducting, as observed by Meissner an d Ochsenfeld, the perm eability does n o t vanish entirely, or if i t does vanish, it does so only in certain regions.—J . S. G. T.

^Magnetic Properties of Superconductors. E . F. B urton (Nature, 1934,133, 684).—Changes of m agnetic flux in 5 coils, arranged in different positions w ith respect to a hollow tin cylinder, occurring as th e cylinder passed through the transition tem perature are reported. The results support, to some ex ten t, the conclusions o f Meissner an d Ochsenfeld (Met. Abs., 1934, 1, 289) and supple­

ment the work of Mendelssohn and B a b b itt (preceding ab stract).—J . S. G. T.

* Superconductivity and Fermi-Dirac Statistics. J . A. K ok (Nature, 1934, 134,532-533).—The specific h eat of some elem ents, e.g. zinc and silver, does not follow D ebye’s T 3 law in th e non-superconducting sta te a t low tem peratures.

The deviations, Ac, are a ttrib u ta b le to the presence of a free-electron gas obeying the Ferm i—D irac statistics, an d it is now shown th a t th ey can be cal­

culated w ithout reference to a parabolic law of threshold values of heat content.

Satisfactory agreem ent betw een experim ental and calculated values of Ac are found, on th is basis, for thallium , tin , and indium .—J . S. G. T.

*Experiments on Superconductors. T. C. K eeley K . Mendelssohn, and J . R.

Moore (Nature, 1934, 134, 773-774).—Values of th e percentage of th e flux of induction a t th e threshold tem p eratu re which rem ains “ frozen-in ” when the external m agnetic field is reduced to zero were determ ined as follows : m ercury, 0 % ; tin (single crystal), 6 -1 0 % ; tin (polycrystalline), 8 -1 2 % ; lead, 15% ; lead + 1% of bism uth, 4 0 -8 0 % ; lead + 4 % of bism uth, 80-100% ; lead + 10% of bism uth, 100% ; tin + 28% of cadm ium (annealed or unannealed), 100% ; tin + 58% of bism uth, 100%. The percentage is sm all for pure substances. The h eat of tran sitio n does n o t appear a t a definite field strength, b u t over a certain range of field strengths.—J . S. G. T.

*The Role of Electrons in Superconduction. J . S tark (P hysikal.Z ., 1935,36, 515-516).—The effects of electric an d m agnetic fields on electron m otion in crystals are discussed. I t is suggested th a t th e tran sitio n tem p eratu re c h a r­

acterizing the region of superconduction is dependent on th e size of the crystallites in th e cry stal an d th e orien tatio n of th e axes of electronic crystals to the lattices of the crystallites. I t is suggested th a t th e m otion of electron crystals is less im peded in a stretch e d wire th a n in a wire having m any bends.

I t follows th a t the tran sitio n tem p eratu re is lower in th e la tte r th a n in the former. The significance of recrystallization occurring a t the bends is referred to. The dependence o f th e specific h eats an d therm oelectric properties of m etals in the region of superconduction on electron m otion is briefly suggested.

—J . S. G. T.

*The Effect of Size of Crystallites on the Incidence of Superconduction. K.

Steiner and P. G rassm ann (P hysikal. Z ., 1935, 36, 516-519).—R esults w ith tin , in which the size of crystallites present could be altered in ratio up to 10 : 1, show th a t in accordance w ith S ta rk ’s theory (preceding ab stract), w ith increase of crystallite size, th e tran sitio n tem p eratu re indicating the incidence of super­

conduction is decreased.—J . S. G. T.