

Societies and Academies. 
Lonpon. 
Royal Society, May 31.—E. Griffiths and G. W. C- 
Kaye: The measurement of thermal conductivity, 
No. f. 
are described for the rapid precision détermina- 
tion of the thermal conductivities of materials at 
low conductivity. Energy was supplied by electrical 
means and temperatures were measured by thermo- 
couples. An average time for the attainment of the 
“steady state ’’ was 30 minutes or less, and the 
average accuracy of measurement of the conde 
was about 1 per cent. Among the topics discu 
was the thermal resistance at the bounding faces of | A study of catalytic actions at solid surfaces. 
a material, the effect of superimposing layers of 
compressible~ material, the measurement of the 
thickness of compressible material, the dependence 
of the conductivity of timber on structure and 
- moisture-content and the variation of the conductivity 
of rubber with mineral content.—G. W. C. Kaye and 
J. K. Roberts: The thermal conductivities of metal 
crystals. I.—Bismuth. A “plate’’ apparatus 
measuring thermal conductivities as high as 0-02 
C.G.S. with an accuracy of about 1 per cent., using 
specimens 2 cms. by I cm. in area and about 1 or 
2 mm. in thickness was used. The conductivities 
of single crystals of metallic bismuth in directions 
parallel and perpendicular to the trigonal axis at 
18° C. are, in C.G.S. units, o-or59 and 0o-0221. The 
ratio of conductivities is 1-39. The mean value 
O-orgt agrees well with the figure 0-0193 obtained 
on bars by Jaeger and Diesselhorst in 1899. Thus 
in the case of bismuth metal in the aggregate, the 
distribution of the constituent small crystals is 
random, and the effect on the thermal conductivity 
of any inter-crystalline layers is not appreciable— 
C. V. Drysdale and S. Butterworth: The distribution 
of the magnetic field and return current round a 
submarine cable carrying alternating current. Pt. I. 
(By C. V. Drysdale.) An exact knowledge of the 
magnetic field distribution in the neighbourhood of 
a submarine cable is of great importance in connexion 
with leader gear and the propagation of radio signals 
between submerged stations. Investigations have 
been carried out since 1918 at the Admiralty Experi- 
mental Stations at Parkeston Quay and Shandon, 
with the object-of determining the magnitude and 
phase of the magnetic field in and above the surface, 
and of the return current in the water, as well as 
the velocity of propagation and attenuation of the 
electro-magnetic waves in the water and the shielding 
effect of the cable armouring. Measurements were 
made with an alternating current potentiometer on 
_ horizontal and vertical search coils above and below 
the surface and on electrodes in the water at fre- 
are from 50 to 500 periods per second. Pt. IT. 
(By S. Butterworth.) Expressions for the distribu- 
tion of electric force due to a long cable carrying 
alternating currents and immersed in a sea of uniform 
depth have been obtained in the form of Fonrier 
integrals and formule have been developed which 
cover the following cases: (1) The field above the 
surface of the sea when the depth of the water is 
small; (2) the field above the sea at large distances 
from the cable, there being no restriction in regard 
to depth; (3) the field below the surface of the sea 
for points vertically above the cable; and (4) the 
field below the surface of the sea at large distances. 
from the cable when the depth of the sea is great. 
The results for points above the surface of the sea 
_ have been verified by tests in which the sea is re- 
_ placed by a sheet of lead. The formule are in 
NO. 2797, VOL. 111] 
q 
Three types of apparatus of the “ plate” 
793 
‘substantial agreement with actual sea observations. 
| —S. Russ: The effect of X-rays of different wave- 
lengths upon sonie animal tissues. Two regions in 
the X-ray spectrum were selected, and it was arranged 
that equal doses of X-ray energy were absorbed in 
their passage through the tissues. In these circum- 
stances more profound effects were produced by the 
longer wave-lengths (0-45-0-30 A.U.) than by the 
shorter wave-lengths (about 0-168 A.U.), both upon 
the normal skin of the rat and upon Jensen's rat 
“sarcoma. The degree of this differential action is 
‘more pronounced in the case of the skin than it is 
‘for the tumour, the numerical values being 6 and 
2-6 respectively. These numbers are termed ‘‘ thera- 
peutic factors.’’—E. F. Armstrong and T. P. Hilditch : 
Pt. 
—The action of alumina and certain other oxides in 
“promoting the activity of nickel catalyst. In the 
absence of any carrier for the nickel, the presence of 
a small proportion (up to 5 per cent.) of an oxide, 
‘such as that of aluminium or magnesium, increases 
‘the catalytic activity of the reduced metal. When 
the nickel oxide is deposited on a support, e.g. 
kieselguhr from which the metallic constituents have 
been extracted, the catalyst is inferior to that on 
natural kieselguhr. Its activity is restored if about 
20 per cent. of alumina is precipitated with the 
hydroxide of the nickel. If this proportion of alumina 
is first deposited on the acid-extracted kieselguhr 
and the nickel hydroxide or carbonate then precipitated 
on to this preparation, the catalytic activity of 
‘the product generally exceeds that of nickel on the 
natural kieselguhr. It seems that the action of the 
non-reducible oxide is mainly mechaaical and con- 
nected with increase or diminution of the surface 
area of the exposed nickel—N. K. Adam: The 
structure of thin films. Pt. IV.—Benzene deriva- 
tives—A condition of stability in monomolecular 
films. Derivatives of benzene, such as hexadecyl 
phenol, containing one long chain and one polar 
group in the para position, orient on water surfaces 
like fatty acids, the phenol group forming the head 
of the molecule in contact with the water. Com- 
pounds such as cetyl palmitate, palmitic anilide, etc., 
which contain one polar group placed between two 
chains or one chain and a ring, do not adhere to a 
water surface well enough to give measurable con- 
densed films. The para sulphonic acids in hexadecyl 
and octadecyl benzene give soap-like solutions in 
water. Pt. V.° Bromine in the «a position, in the 
bromo-acids and esters, increases the cross-section 
of the molecules in the films. The bromine atom 
increases the solubility of films of the higher fatty 
acids. It also lowers the temperature of change 
‘from condensed to expanded films; but it does 
not appreciably affect the properties of the films, 
when expanded. The double linkage in the a 8 
position relative to the COOC,H, group increases 
the cross-section of the molecule in the films, as it 
does in iso-oleic acid.—W. B. Rimmer: The spectrum 
ofammonia. Of the three bands which are associated 
with the spectrum of ammonia, the ultra-violet band 
has already been investigated in detail by Fowler 
and Gregory, and is represented in the solar spectrum. 
The ‘‘ Schuster bands ’’ \ 5635 and \ 5670, have given 
ne sign of resolution under high dispersion, and it 
is probable that they do not occur in the solar 
spectrum. The ‘‘a band ’”’ of Eder and Valenta is 
of great complexity, consisting of about 3000 lines ; 
there is no conclusive evidence that this band occurs 
either in the solar spectrum or in the spectrum of 
sunspots. The Schuster bands seem to have their 
origin in the normal ammonia molecule and the 
ultra-violet band is probably due to emission from 
