ao” 
The chemical analysis of matter is not an ultimate 
one. It has appeared ultimate hitherto, on account of 
the impossibility of distinguishing between elements 
which are chemically identical and non-separable 
unless these are in the process of change the one into 
the other. But in that part of the periodic table in 
which the evolution of the elements is still proceeding, 
each place is seen to be occupied not by one element, 
but on the average, for the places occupied at all, by 
no fewer than four, the atomic weights of which vary 
over as much as eight units. It is impossible to 
believe that the same may not be true for the rest of 
the table, and that each known element may be a 
group of non-separable elements occupying the same 
place, the atomic weight not being a real constant, 
but a mean value, of much less fundamental interest 
than has been hitherto supposed. Although these 
advances show that matter is even more complex 
than chemical analysis alone has been able to reveal, 
they indicate at the same time that the problem of 
atomic constitution may be more simple than has been 
supposed from the lack of simple numerical relations 
between the atomic weights. 
The general law is that in an wray change, when 
ahelium atom carrying two atomic charges of positive 
electricity is expelled, the element changes its place 
in the periodic table in the direction of diminishing 
mass and diminishing group number by two places. 
In a B&-ray change, when a single atomic charge of 
negative electricity is expelled from the atom as a 
B particle, and also in the two changes for which the 
expulsion of rays has not yet been detected, the element 
changes its position in the table in the opposite direc- 
tion by one place. j 
The discussion was continued by Mr. A. Fleck, who 
has determined experimentally what element each of 
the short-lived radio-elements most resembled, and 
whether it was separable from the ordinary element 
by fractional methods. 
The results of the work show that :— 
1. Uranium-X and radio-actinium are chemically 
identical with thorium. 
2. Mesothorium-2 is 
actinium. 
3. Radium-A is chemically identical with polonium. 
4. Radium-C, thorium-C, actinium-C, and radium-E 
are chemically identical with bismuth. 
chemically identical with 
5. Radium-B, thorium-B, and actinium-B are 
chemically identical with lead. 
6. Thorium-D and actinium-D are chemically 
identical with thallium. 
In the cases in which the inseparable elements are 
common elements these latter have all atomic weights 
above 200, and occupy one or other of the last twelve 
places of the periodic table. 
Closely allied to the discussion was the next paper 
by Dr. G. Hevesy, entitled ‘‘ Radio-active Elements as 
Indicators in Chemistry and Physics.” 
_ By means of an a-ray electroscope of ordinary sensi- 
tiveness it is possible to measure accurately as small 
a quantity as 10-17 orm. of a radio-active substance 
having a half-value period of one hour. The extra- 
ordinary simplicity and at the same time sensitiveness 
with which these extremely small quantities of radio- 
active bodies can be determined makes them of the 
greatest use not only in studying substances in great 
dilution, but also as indicators of physical and chemical 
processes. Radio-active indicators are conveniently 
divided into two principal groups. To the first group 
belong those the use of which as indicators depends 
only on their physical properties, and not on their 
chemical properties. Several examples of the use of 
indicators of this kind were given. The radio-active 
elements may be used chemically as indicators of the 
metals from which they are known to be non-separable. 
NO. 2298, VOL. 92] 
NATURE 
[ NOVEMBER 13, I913 
In this way 10-* mg. of lead is quantitatively deter- 
minable. a 
The section then divided into*physico-chemical and 
metallurgical divisions. After Dr. Patterson had com- 
municated certain novel suggestions for the nomen- 
clature of optically active compounds, two papers were 
read by Dr. B. de Szyszkowski, of Kieff. He first 
described the influence of sodium and potassium 
chloride in varying concentration upon the distribution 
of benzoic and salicylic acids. Both the affinity con- 
stant and partition coefficient were calculated. The 
former first rises, passes through a maximum, and 
then falls as the concentration of the salt is con- 
tinually increased. Maxima of solubility are shown ~ 
to exist for salicylic acid and 1:3: 5-dinitrobenzoic 
acid. The increased solubility of acids in presence of 
salts is due to double decomposition and increase of 
the affinity constant, both factors contributing towards 
the diminution of the undissociated proportion of the 
acid. 
The second paper dealt with solubility and distribu- 
tion. 
Dr. Prideaux, in a paper entitled ‘“‘The Hydrogen 
Ion Concentration of the Sea and the Alkali-carbon- 
dioxide Equilibrium,” supported the opinion that the 
interaction between the small quantities of carbon 
dioxide and free alkali is a most important factor 
controlling life in the sea and dealt at some length 
with the physico-chemical constants which connect 
the concentrations of the hydrogen and carbonate ions. 
It is supposed that the first and second dissociation 
constants of carbonic acid are both altered in saline 
solution. A lively discussion followed, in which Prof. 
Sérensen, Dr. Syzszikowski, and Dr. E. F. Armstrong 
tool part. 
Metallurgical Chemistry. 
The metallurgical section sat separately on two 
mornings, Prof. T. Turner being in the chair. The 
first item was a discussion on metals, crystalline and 
amorphous, introduced by a paper from Dr. W. 
Rosenhain, who submitted advance proofs of the full 
paper to the meeting. The ‘‘amorphous”’ theory, as 
it now stands, appears to consist of three distinct 
propositions. The first of these is that mechanical 
disturbance of the material at the surface of a piece 
of crystalline metal, locally destroys the crystalline 
nature of the material and produces on the finished, 
polished surface a thin film of amorphous metal. 
The second is that, just as friction and polishing of 
a metal surface produces a thin amorphous layer or 
film, so the internal rubbing which talkes place on 
surfaces of internal slip when crystalline metal is 
plastically strained, will also bring about local dis- 
turbance resulting in the formation of a thin layer 
of amorphous metal. This amorphous metal is re- 
garded as being less dense and much harder than the 
crystalline variety, and its formation is regarded as 
explaining the changes in hardness and density which 
are known to accompany plastic strain. 
The third proposition is that where the constituent 
crystals of a metal meet, thin films of residual liquid 
metal will remain in circumstances which render 
them incapable of crystallising, so that they will con- 
stitute thin films of undercooled liquid or amorphous 
metal acting as an intercrystalline cement. 
The author reviewed in detail how far these pro- 
positions can be regarded as established. The second 
in particular has been much criticised, but it was 
demonstrated that it offers an explanation for a larger 
number of facts than any rival theofy. 
In the subsequent discussion Dr. G. T. Beilby 
pointed out that interpenetration of the surface layer 
and the polishing powder is not essential, as calcite 
may be polished without any powder. The layers 
