518 
NATURE 
[JuLy 18, 1912 
brilliantly, the illumination waxing and waning as 
the movable electrode moves in and out. 
We have been able to repeat some of these results 
with furnaces of a non-electric character. 
In a further series of experiments various modifi- 
cations were introduced. The two electrodes were re- 
placed by two co-axial tubes, which were mounted 
within the furnace. The central smaller tube was of 
brass, through which a rapid current of water was 
sent; this formed the ‘cold’ electrode. The 
surrounding larger tube of carbon constituted the hot 
electrode, and received its heat from the furnace. The 
electrodes were insulated as before, and into the 
annular space between them hydrogen or nitrogen was 
continually passed. No potential was applied, and 
the currents we obtained with a steadily rising 
temperature and a new carbon electrode are shown | 
in Fig. 6. It will be seen that there was first a small 
“positive ’’ current (which would be produced by 
positive ions crossing from the hot to the cold elec- 
trode), which soon changed into a much larger 
NEW CARBON ELECTRODES 
ME TWEEN ELECTRODES 3 
DISTANCE 
08 
e 88 
2 
w 
x< 
c 
> 
© 0:2 
= ] ‘ 
=) STEADY TEMPERATURE 
ae 
Nm & 
= it 
Zs 
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20MINS, 40 6u BO 100 
TIME 
Fic. 7.—Relation between ionisation current and time for two new carbon electrodes, 
The temperature 
one hot, the other water-cooled. No potential was applied. 
was rising for the first fifty minutes, and was afterwards steady. 
“negative’’ current (in the usual direction); the 
intensity of the latter dropped, and then showed a 
progressive increase with temperature. On taking 
down the apparatus we found that the brass tube 
was coated over most of its length with a thick and 
coherent deposit of carbon, which had _ evidently 
crossed over from the hot electrode. Towards one 
end the deposit was rarer and whitish—presumably 
silica. We associate the maximum negative current 
of Fig. 6 with the passage of silicon and other impuri- 
ties, which are volatilised at about 2000° C. out of 
the carbon electrode. On a second heating neither 
positive rays nor a negative maximum was detected, 
but the ionisation current increased steadily with 
temperature. The transference of carbon from the 
hot electrode to the cold may possibly prove to be an 
explanation, not only of the contamination phenomena 
which gave rise to these experiments, but also of the 
comparatively large accompanying currents. 
Fig. 7 illustrates the results obtained when steps 
NO. 2229, VOL. 89] 
had been taken to increase the difference of tempera- 
ture between the hot and cold electrodes. The carbon 
was new, and the negative maximum again appears. 
Afterwards the furnace temperature was steadied, and 
the ionisation current also kept steady in consequence. 
It will be noticed that we were now dealing with 
currents amounting to large fractions of an ampere, 
and the experiments may fairly be regarded as pro- 
viding a novel means of generating electricity. Their 
direct bearing on the problems of the electric arc and 
the carbon filament lamp is obvious, and we are 
continuing the research with the view of elucidating 
the many underlying phenomena. 
UNIVERSITY EDUCATION IN GERMANY.} 
aps development of the German _ universities 
during the last hundred years has undeniably 
raised them in the eyes of the scientific world, but 
at the same time it has given rise to practical difficul- 
ties which are more and more felt, and, here and 
there, much deplored. | German professors , 
regard scientific research rather than teach- 
ing as their distinguishing task, or at least 
their teaching mostly takes the shape of 
initiation into the methods of research. 
Their lecturing has thus assumed such an 
abstract character that the student coming 
from a higher school in the proud possession 
of a ‘‘certificate of maturity’’ usually finds 
the transition to the new atmosphere of 
thought very hard, and commonly wastes 
more than one term merely in finding a foot- 
ing. At the other end, the step from the 
university into a profession is the reverse of 
easy; the medical faculty, with its clinical 
hospitals and similar arrangements, is really 
the only one which offers a direct training 
for the future. 
A more adequate view of the matter 
seems, however, to be spreading. In the 
meantime a year’s practical training, com- 
plementary to the studies and examinations, 
has been added to the medical course, and a 
similar provision has been made for evan- 
gelical theology. In the university itself the 
importance of mental intercourse between 
the professors and their students is more 
m0 Widely recognised, due to the further 
development of the university seminaries; 
even those professors and ‘“‘privatdocents ” 
who do not conduct official seminaries usually 
hold so-called ‘‘exercises” in addition to 
their lectures. The throng of students is 
great on all such occasions; they themselves feel 
strongly how much less they gain in mental culture 
from mere listening to lectures. Nevertheless the in- 
stitution must be regarded as in some respects very 
incomplete. 
In many subjects the seminary deals only with 
strictly scientific questions (from which the themes 
for dissertations are frequently drawn), whereas more 
practical discussions are equally desirable. Besides 
this the number of those admitted is usually rather 
small, and indeed not unwisely so, because it is only 
then that a lively debate becomes possible; a too 
numerous membership easily tends to make the indi- 
viduals embarrassed and silent. In most cases, too, 
only those students are admitted who have already 
been several terms in the university, whereas it is 
precisely the freshman who is most in need of help. 
1 Abridged from an article by Prof. Wilhelm Miinch, professor of pedagogy 
in the University of Berlin, in the Report of the U.S. Commissioner of 
Fduecation for the year ended June 30, rgr1, vol. i., just received from 
Washington. 
