Marcu 14, 1907] 
NAOT: 
461 
After a very lengthy investigation of the biochemical 
changes which occur in the natural ripening of the wheat 
berry, its preparation or ‘‘ conditioning ’’ in the mill, and 
the influence of variations in the treatment of the result- 
ing flour in the bakehouse, I am fully convinced that it is 
no longer the bakehouse that has to give the final verdict 
on the qualities of flour, as laboratory methods can now 
provide all the data necessary for inferring the antecedent 
conditions, defining the present qualities, and anticipating 
the future evolution of wheat or its product, flour. 
A. J. Banks. 
Waterloo, Liverpool, March rt. 
Ionisation and Anomalous Dispersion, 
In Nature of February 21, Prof. Wood, referring to my 
letter of January 17, says that the effects observed were 
probably due to disturbance of the density gradient of the 
sodium vapour caused by ‘‘ local heating by the wire.’ I 
am afraid that in my letter I cannot have described the 
experimental arrangement sufficiently clearly; at any rate, 
Prof. Wood seems to be under a mistaken impression. 
The wire was merely an electrode insulated from the 
tube containing the sodium vapour, but connected to one 
pole of a battery, the other being connected to the tube. 
A current passed through the sodium vapour, or the 
nitrogen left in the tube after exhaustion and heating, | 
presumably an ionisation current; and this was of the 
order of one microampere, and could hardly produce much 
local heating. 
Be this as it may, since I left Aberystwyth my pupil, 
Mr. Needham, noticed an effect which, if confirmed, 
appears to me to be decisive in favour of a connection 
between ionisation and dispersion. While the tube was 
heated, by a flame as usual, with 1o volts there was a 
current of 4 divisions and an anomalous dispersion of 
9 divisions. On raising the voltage to 58 volts, the 
current rose to 10 divisions, but the anomalous dispersion 
immediately fell to sero, and thereafter slowly increased 
to a value somewhat greater than before. 
That an increase of current, and presumably of local 
heating, if there be any, should diminish the dispersion 
temporarily ean hardly be understood, unless the systems 
producing the dispersion are themselves electrically charged 
and swept away to the electrode. I hope shortly to in- 
vestigate the whole question fully, so as to decide definitely 
what connection, if any, exists between ionisation and dis- 
persion. G. A. Scuort. 
Physical Institute, Bonn, February 26. 
The Rusting of Iron. 
In Nature of February 21 (p. 390) Prof. W. R. Dunstan 
states that rusting of iron takes place in the presence of 
water and oxygen when every trace of carbonic acid has 
been removed. To a certain extent this is the result 
obtained by our chemist, but his experiments proved con- 
clusively that rusting must be due to an admixture of 
carbonic acid, for with improved precautions against its 
presence rusting was enormously reduced, and, this is 
important, confined to one or two spots. In some cases 
this local rusting took place where the steel samples rested 
on the glass vessels, and it was but natural to suppose 
that this local corrosion was brought about by silicie acid 
of the glass. The obvious precaution was to arrange an 
iron bowl in the centre of the glass vessel into which 
water could be distilled, but although this apparatus was 
constructed, it was not used, because if corrosion can be 
caused by the silica of the glass, then it may also be 
caused by specks of exposed slag in the iron or by the 
oxidised specks of manganese sulphite which can be seen 
with the microscope, or by other impurities. Corrosion 
may even be brought about by carbonic acid occluded in 
the iron. In order to settle the question, the experiment 
should be repeated with a piece of iron of absolute purity. 
C. E. STROMEYER. 
Manchester, March 5. 
NO. 1950, VOL. 75] 
. A Problem in Chance. 
Tue law of probability is often illustrated by the simple 
method of supposing a bag filled with an equal number 
of white and black balls, which are presumably uniformly 
distributed within the bag. It is stated that the chances 
are equal that any extracted ball will be black or white. 
I am desirous of ascertaining how this equality of 
extraction of either colour would be disturbed if it be 
assumed that the balls are not merely inert, but that 
there is an inherent tendency for like-coloured balls to 
cluster together. Two subsidiary and mutually alternative 
conditions may be further assumed: either the tendency 
of the black balls to cluster together is greater than that 
existing between the white balls, or it is equal. It is the 
former of these two subsidiary conditions that interests me. 
Perhaps I may state the problem in more definite form. 
Assume 2000 balls, of which half shall be black and half 
white, placed in a bag. The intensity with which the 
latter tend to cluster=d, and that of the former is greater, 
but to a less degree than half as much again. The balls 
are extracted in groups of eight. In four separate extrac- 
tions, what will be the probable proportion of black and 
white balls at each extraction? And how many extractions 
will have to be made before it is probable that an equal 
number of black and white balls will have been with- 
drawn? Gro. P. MupcE. 
London Hospital Medical College. 
THE UNIVERSITY OF THE CAPE OF 
GOOD HOPE. 
N the invitation of Sir Lauder Brunton, a meet- 
ing took place at his residence on January 21 
of gentlemen interested in university education. 
Among those present were Sir Arthur Rucker (of the 
London University), Dr. Donald MacAlister (then of 
Cambridge University, and president of the General 
Medical Council), Prof. Perry (Royal College of 
Science), Sir W. Arbuckle (Agent-General of Natal), 
-Sir David Gill, Sir John Buchanan, and Mr. Howard 
d’Egville, honorary secretary Imperial Federation 
(Defence) Committee. Prof. Osler (of Oxford Uni- 
versity), Sir Norman Lockyer, K.C.B., Sir Thomas 
Fuller (Agent-General for Cape Colony), and Prof. 
Stirling, dean of the medical faculty of the Victoria 
University, were unfortunately prevented from attend- 
ing. Copies of the proposals provisionally agreed to 
by the committee of University of the Cape of Good 
Hope, relative to the re-organisation of that Uni- 
versity, had been circulated before the meeting, and 
formed the basis of the evening’s discussion. The 
result was a consensus of opinion on several leading 
issues, which may be summarised as under :— 
(1) That in the existing condition of South Africa 
the interests of the higher education of the country 
would best be served by the continuance of only one 
examining and degree-conferring university. 
(2) That the conferring on single colleges in the 
country the power of granting degrees to their own 
students would be detrimental to higher education, 
and specially injurious to the status of all such South 
African graduates. Such degrees would be depreci- 
ated, not only in the estimation of the people of the 
country itself, but also outside the colony, and would 
not have the same value or consideration given them 
which degrees granted by one general University 
would receive. The tendency of multiplying degree- 
granting institutions in the circumstances such as 
those existing in South Africa would be in the direc- 
tion of unhealthy competition, which would inevit- 
ably lower, and not raise, the worth of degrees so 
obtained. 
(3) That sound education would be promoted by 
associating in examinations the teacher with indepen- 
dent examiners, but the University should control all 
