APRIL 14, 1923] 
















































is now impossible, since it appears proved by Lang- 
muir’s work that there is no difficulty in accounting 
both qualitatively and quantitatively for many cases 
of adsorption, by means of the already very familiar 
forces which cause combination between metals and 
oxygen to form oxides, or the forces which bring 
about solution. 
_ Obviously adsorption cannot be defined as “ that 
which occurs at the surface of a colloid’’; since 
colloids themselves are not yet a well-defined class 
of substances, and indeed the best studied cases of 
ads oo are at plane interfaces, not at the surfaces 
of colloids. 
With the definition of adsorption proposed, a 
process would be excluded if, as with haemoglobin 
ind oxygen, combination occurs only at some defined 
ocality on the surface. Similarly, the ordinary 
tions of organic chemistry will be excluded, as 
hey should be, since the substances taken up go to 
jefinite atomic groupings in the molecule. The com- 
bination of oxygen with hemoglobin is seen to belong 
o the same class as most organic reactions. 
It remains to examine whether the definition is 
actically applicable to known cases of adsorption, 
is well as theoretically justified ; and whether, in 
case of oxygen and hemoglobin, the arguments 
ally put forward in support of the adsorption 
rocess are cogent enough to override the definition, 
_ All cases of adsorption, from a gaseous phase, or 
from solution, on plane, or nearly plane, interfaces, 
e obviously compatible with the definition, since the 
common method of calculating the amount of ad- 
sorption assumes uniformity of distribution on the 
urface, and the results are generally expressed per 
iq. cm. of interface. 
In the cases of adsorption on colloidal surfaces, 
when the extent of surface is usually not known, 
the adsorption is expressed per gram of 
dsorbent, the definition is probably also applicable. 
lenburg (Zeitsch. f. physikal. Chemie, vol. 83, 
D. 622) described experiments showing in several 
ases that the adsorption on different specimens 
the same adsorbent, prepared, however, under 
erent conditions, varied in a precisely similar way 
h concentration for each adsorbent, but the total 
mount adsorbed per gram was proportional to a 
factor in each case, this factor being presumably 
proportional to the area of the adsorbent. 
In proposing the theory that the oxygen in oxy- 
hemoglobin is held by adsorption, Wo. Ostwald 
oll. Zeitsch., vol. 2, pp. 264, 294) based the argument 
on two supposed facts: first, that no definite satura- 
tion point of oxygen with hemoglobin could be found, 
‘a fact now shown to be incorrect ;, and, second, that 
the amount of oxygen taken up at different pressures 
‘could be fairly accurately represented, under certain 
‘conditions, by the so-called ‘‘ adsorption isotherm,” 
y =k ed =amount taken up, c=concentration of 
en). 
; he mere fact that the variation of the amount 
taken up fits the ‘adsorption isotherm ’’ does not 
Seem now to be a sufficient ground for classing 
a process as adsorption. The ‘‘isotherm’’ has, 
until quite recently, been an empirical fact with- 
out theoretical explanation; and not only does 
it contain two independent arbitrary constants, which 
makes the fitting of a set of experimental data easier 
than would be the case otherwise ; but also it is, at 
the best, usually only accurate at low concentrations, 
divergences being found at higher concentrations. 
A more accurate equation relating amount adsorbed 
o concentration has been deduced recently (Henry, 
Phil. Mag., vol. 44, p. 689, 1922) on the assumptions 
of a small range of molecular attraction and a mono- 
molecular adsorbed layer, using well-established 
NO. 2789, VOL. 11] 
le 
NATURE 
497 
equations of the kinetic theory; and the author 
also gives a derivation of the “ adsorption isotherm ”’ 
on theoretical grounds. It would seem undesirable, 
however, to use the form of the relation between 
amount adsorbed and concentration as a criterion 
of adsorption, for this relation can never be a very 
simple conception, depending as it does on so many 
factors; but nothing could be simpler than to 
conceive of a surface as possessing either localised 
or diffuse attraction for a substance it takes up. 
It may be that in some instances it is not yet possible 
to form any estimate of the fraction of the surface 
covered ; yet as accurate knowledge of the dimensions 
of molecules and of their orientation on surfaces 
accumulates, the applicability of the criterion here 
suggested will increase. I have tried to show, 
however, that it is already more generally applicable 
than any other. N. K. Apam. 
The University, Sheffield, March 6. 


Labour and Science in Industry. 
THE article by “ F. S. M.”’ under this heading in 
Nature of March 24, p. 385, emboldens me to inquire 
whether the time has not come for a really searching 
scientific re-examination of the natural fundamental 
basis of the economic system under which we perish. 
That it is necessary to ask such a question as that in 
this article, whether, after a century’s unparalleled 
progress in the domination of the forces of Nature and 
the fertile labours of inventors and producers, the 
average lot of the people is really better than it was 
in consequence, suggests a certain lack of scientific 
imagination. The question which many thoughtful 
people are now asking themselves, and which a few 
scientific men at least should have asked before the 
War, is not whether the material lot of the people is up 
to what it was before the use of science, but why is it 
not vastly improved. What kind ofa civilisation ought 
to be the result, if science were directed in accordance 
with natural laws to the constructive purposes of 
life, rather than only so for the purposes of mutual 
destruction ? Civilisation can scarcely revert in 
peace-time to economic law, in which the tokens of 
wealth usurp the place of reality, without raising the 
very general aspiration that the advantages of war 
and peace might be combined by proceeding accord- 
ing to natural laws in peace-time. 
The first economists, the French Physiocrats, did 
make an effort to base their system on the laws of 
Nature, and in their doctrine, that the origin of 
wealth was the land, and in the later doctrine of Marx, 
that it was in human labour, certain obvious elements 
of natural truth were embodied. But in the present 
system there is no natural truth obvious at all. It is 
an offence against common sense. The production 
of wealth to-day is a relatively finished science, in 
which probably little that is fundamental remains un- 
known ; whereas a century ago it was an empirical art 
as different from the present science as astronomy is 
from astrology or chemistry from alchemy. But the 
science of distributing the product—that is, the science 
of token wealth—is so little understood that the most 
incredible consequences are accepted as natural and 
inevitable. 
In a natural community, if people were short of the 
necessities of existence, and knew how, they would 
produce and consume them. In ours, with the return 
to conditions of peace and victory, they are idle by 
the million and deteriorate mentally, morally, and 
physically, dumbly acquiescent in the requirements 
of a system no one pretends to understand. If one 
asks why, it is because of certain conventions with 
regard to bits of metal and paper to which we have all 
