: 
® 
-OcTOBER 19, 1916] 
silver, and should be worked up to produce all of 
these. This being so, it does not follow that the 
roasting of the ore for acid should necessarily be 
carried on at the same place as the smelting of | 
the roasted material for the metals. Moreover, 
it is just the fact that this ore is a potential 
source of acid which renders it necessary for the 
bulk of the concentrates to be shipped from 
Australia, where the market for acid is limited, to 
a country like Great Britain, with nine times the 
population of Australia, and highly developed 
industries which can absorb the acid. 
Stated broadly, if Great Britain is going to 
produce all the zinc needed for home consumption, 
the output of “primary ” spelter will have to be 
increased at least fivefold. At present neither 
electrolytic zinc nor electro-thermally distilled 
zinc can compete commercially in this country 
with that obtained by distillation with coal in 
externally fired retorts heated by gas. Unques- 
tionably the most difficult part of the problem is 
the training and organisation of the labour re- 
quired for this process. Difficult though this is, 
it should be undertaken without delay, for America 
has shown that it can be done, and done rapidly 
when necessary. The establishment in _ this 
country of a zinc-smelting industry on a scale 
commensurate with its needs is most urgently 
required. There is no reason, if there is a 
proper application of organising ability, technical 
‘knowledge, perseverance, and resourcefulness— 
such as is now being exhibited on the British 
battle-front—why success should not be achieved. 
It would be an industrial victory of the first mag- 
nitude, and it would remove a peril in which this 
‘country was placed by the outbreak of war, which 
has been all too imperfectly realised, and should 
never be allowed to recur. 
No reference has been made in this article to the 
possibility of assistance to be given by the British 
Government. As already mentioned, the Austra- 
lian Government has dealt with the situation 
created there, and the Prime Minister, Mr. Hughes, 
is credited with having a very definite policy as 
to the future of the zinc mining and smelting in- 
‘dustry, a policy in which Australia and Great 
Britain are immediately concerned. Whether 
and to what extent the statements relative to this 
which have appeared in the Press are trustworthy 
and authentic it is impossible to say. Some of 
them have been so inherently improbable that it is 
wisest to suspend judgment until the matter has 
been settled and an authoritative announcement 
made. There is every reason why there should 
be as little delay as possible in reaching a 
‘decision and acting upon it. 
H. C. H. Carpenter. 
PROF. PIERRE DUHEM. 
5 lpedde precise formulation of the fundamental 
principles of mathematical physics may be 
‘said to be the outstanding feature of the work 
of Pierre Maurice Marie Duhem, whose sudden 
‘death at Cabrespine (Aude) on September 14 
‘Was announced in NaturE of September 2r. 
NO. 2451, VOL. 98] 
NATURE 131 
Born at Paris on June 10, 1861, Duhem in 
due course graduated in science, and for many 
years past held the chair of theoretical physics 
in the University of Bordeaux. 
Although for a considerable time a correspond- 
_ing member of the Academy of Sciences, it was 
not until 1913 that the distinction of full member- 
ship was conferred on him 
Unlike most physicists, who take as their 
starting-point the equations of reversible 
dynamics, Duhem commenced with thermo- 
dynamics, and his treatise on the Thermo- 
| dynamic Potential, published in 1886, will 
| always remain a classical work of reference on 
the subject. 
Gibbs (1876-8) was beginning to attract atten- 
j 
| 
| 
| 
At that time the work of Willard 
tion to the potentialities of thermodynamics in 
relation to chemical theory, and Duhem became 
an early exponent of the new methods. In 1893 
he published his “Introduction A la Mécanique 
chimique,” which was followed in 1897-9 by a 
much more comprehensive work jin four volumes, 
entitled ‘“Traité élémentaire de mécanique 
chimique fondée sur la Thermodynamique.”’ 
A large portion of this work is in a high 
degree original. We may instance the detailed 
“| studies of ternary and other mixtures and the 
use 
of trilinear co-ordinates in this con- 
nection as one of the interesting features of 
the work, but perhaps the most remarkable 
sections are those dealing with false equilibria 
and explosions, in which the author abandons 
the limitations of “classical mechanics” and 
invokes the assistance of a retardation analogous 
to friction in explanation of the observed pheno- 
mena. About the same time also appeared his 
“Cours de physique mathématique,” dealing with 
hydrodynamics, elasticity, and acoustics. 
The more technical applications of Duhem’s 
work on physical chemistry-form the basis of his 
“Thermodynamique et Chimie,” which appeared 
a little later, and has been translated into 
English. In 1911 Duhem endeavoured to unite 
thermodynamics and mechanics in a compre- 
hensive treatise on energetics covering statics, 
dynamics, hydrodynamics, elasticity, and physical 
chemistry. In a series of smaller contributions, 
entitled ‘Recherches sur l’Hydrodynamique, ”’ 
Duhem gave a detailed discussion of certain 
aspects of the study of fluid motions. : 
If the properties of matter occupied so large 
a place in Duhem’s work, electricity was by no 
means overlooked. A volume of 228 pages, pub- 
lished in 1902 (Paris: A. Hermann), is devoted 
to a critical and historic study of Maxwell’s 
electric theories. About the same time appeared 
the volumes in commemoration of the twenty- 
fifth anniversary of the doctorate of H. A. Lorentz 
(1900), and the sixtieth birthday of Boltzmann 
(1904). To the former Duhem contributed a 
paper on Helmholtz’s electrodynamic theories 
and the electromagnetic theory of light, while to 
the latter he presented in June, 1903, an 
important contribution on the problem of electric 
| stability. 
Historical studies would likewise appear to 
