622 
NATURE 
[May 5, 1923 

Societies and Academies. 
Lonpon. 
Royal Society, April 26.—W. A. Bone, D. M. 
Newitt, and D. T. A. Townend: Gaseous combustion 
at high pressures. Pt. III.—The energy-absorbing 
function and activation of nitrogen in the combustion 
of carbon monoxide. Nitrogen can no longer be 
regarded as an inert gas in the combustioa of carbon 
monoxide, because when present as a diluent in a 
mixture of two volumes of carbon monoxide and 
one volume of oxygen undergoing combustion in 
a closed vessel under high pressure, it exerts an 
energy-absorbing influence which (a) retards attain- 
ment of maximum pressure, and (b) diminishes 
maximum temperature attained in explosion. The 
effects are much greater than those due to any other 
diatomic diluent. The energy so absorbed by 
nitrogen during the combustion period is slowly 
liberated as the system cools down after attainment 
of maximum temperature, and consequently the rate 
of cooling is greatly retarded. These effects are very 
marked in the case of a carbon monoxide-air mixture 
(2CO +O,+4N,). In consequence of such energy- 
absorption, nitrogen becomes chemically ‘‘ activated ”’ 
in such explosions, and while in this condition will 
combine with oxygen, forming oxides of nitrogen. If 
no nitrogen be present in a carbon monoxide-oxygen 
(2:1) mixture, carbon monoxide burns in oxygen at 
high pressures almost as rapidly as does hydrogen. 
There is no correspondingly large (if any) energy- 
absorbing effect (other than purely “ diluent ”) when 
nitrogen is present in hydrogen and oxygen mixtures 
similarly undergoing combustion, and there is no 
evidence of nitrogen being then activated. Two or 
three per cent. of hydrogen in a carbon monoxide- 
air mixture undergoing combustion prevents any 
material activation of the nitrogen. It appears that 
the influence of nitrogen in the carbon monoxide- 
oxygen explosions is due to its ability to absorb 
the particular quality of radiation emitted; such 
radiation is known to be of a different wave- 
length from that emitted during the flame-combustion 
of hydrogen. In other words, there seems to be 
some constitutional correspondence between carbon 
monoxide and nitrogen molecules, whereby the 
vibrational energy (radiation) emitted when one 
reacts with oxygen is of a quality readily absorbed by 
the other, the two acting in resonance.—R. A. 
Watson Watt and E. V. Appleton: On the nature 
of atmospherics. Observations with a cathode ray 
oscillograph, on the temporal variations of the electric 
force occurring in radio telegraphic atmospherics 
are described. The principal constants of six hundred 
typical atmospherics are examined. A bare majority 
are quasi-periodic, consisting normally of one com- 
plete oscillation, of duration 2000 micro seconds, 
the mean change of field being 0-128 volts per metre, 
with no marked unbalanced transport of electricity 
on the whole group. The second group consists 
of aperiodic impulses, of duration generally about 
1250 micro seconds, but frequently reaching 0-025 of 
a second, the mean change of field being 0-125 volts 
per metre, with a seven to one numerical predominance 
of discharges tending to carry negative electricity 
to earth in the receiving antenna.—I. Masson and 
L. G, F. Dolley: The pressures of gaseous mixtures. 
Measurements have been made at 25° of the com- 
pressibilities up to 125 atm. of ethylene, argon, 
oxygen, and a series of binary mixtures of these. 
The volume of a compressed mixture usually exceeds 
the sum of the separate volumes of its two components, 
the excess depending on the molecular ratio of the 
NO. 2792, VOL. 111] 

two gases chosen and upon the pressure. Thus with 
an equimolecular mixture of argon and ethylene 
at 80 atm. the volume is greater than the additive 
value by 24 per cent. At a given pressure there 
is an “‘optimum’”’ composition, and with a given 
composition there is an optim pressure. Oxygen- 
ethylene mixtures behave quantitatively in the same 
way as argon-ethylene; oxygen and argon when 
mixed show a negligible volume increase, and are 
individually equally compressible. The pressure of 
a mixture at high densities exceeds the sum of those 
measured for the separate constituents ; at moderate . 
densities it is definitely less. The former occurrence 
is due to the actual space filled by the molecules ; 
the latter is due to a mutual cohesion between each. 
—T. R. Merton and R. C. Johnson: On spectra 
associated with carbon. The spectral changes due 
to the admixture of helium to vacuum tubes contain- 
ing carbon compounds, and the conditions for 
isolating the band spectra associated with carbon, 
have been investigated. The “high pressure CO” 
bands can be isolated almost completely; the 
“comet-tail’’ bands are found in vacuum tubes 
containing helium and carbon monoxide. In the 
presence of helium the distribution of intensity in 
the comet-tail bands differs markedly from that 
observed by Fowler in tubes containing carbon 
monoxide at very low pressures. By the admixture — 
of hydrogen the comet-tail bands are replaced by © 
a system of triplet bands,.and the wave-lengths of 
the heads of these bands fall into two distinct band 
series. In helium containing a small quantity of 
carbon monoxide a new liae-spectrum has been 
observed under suitable conditions of excitation, 
which is attributed to carbon.—W. R. Bousfield and 
C. Elspeth Bousfield: Vapour pressure and density 
of sodium chloride solutions. A standard set of 
vapour pressure determinations at 18° C. for aqueous 
solutions of common salt at all concentrations was 
required. Water and the solution were introduced 
into the legs of a V tube surmounting a barometric” 
column of mercury, excluding all air. This necessitated 
the boiling of the solutions so that they became of 
unknown concentration. The vapour pressure obser- 
vations were therefore correlated to the densities of 
the solutions and the latter with a complete set of 
density observatio.is at 18° C. made on solutions of — 
known concentration accurate to +2 in the fifth — 
place of decimals.—F. A. Lindemann and G. M. B. — 
Dobson: A note on the temperature of the air at 
great heights. The relatively high temperature of — 
the atmosphere above 60 km. appears to be due to 
absorption of an appreciable amount of direct solar 
radiation. Thus there should be a large variation 
in cemperature at these great heignts. Some evidence 
of such variation has been found.—G. H. Hardy and 
J. E. Littlewood : On Lindeléf’s hypothesis concerning 
the Riemann zeta-function. a 
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u 
Physical Society, March 23.—Dr. A. Russell ecailh 
chair—W. J. H. Moll: (1) A new moving-coil © 
galvanometer of rapid indication. The galvanomete 
is designed to secure rapid indication and steadin 
of reading without unduly sacrificing the sensibilit 
The coil is long and narrow, and therefore of sma 
moment of inertia; the mirror is supported by th 
wires forming the coil, between which it is slipp 
and the coil is supported between an upper and 
lower vertical wire, as distinct from strips, made 
of silictum bronze and put in tension. (2) A thermo- 
pile for measuring radiation. The thermopile 
designed to be quick-reading and free from ze 
errors, as well as sensitive. The cold junctions are — 
in contact with metal masses, and in order that the 
