January 7, 1897] 
NATURE 
HT 
be as observed. He thus arrived at the theory of electro- 
motive molecules which, with extraordinary insight and 
thoroughness, he worked out in its relations to all the 
electromotive phenomena of nerve and muscle when in 
the unexcited state. But, in doing this, he met with 
unexpected difficulties. So long as his observations were 
limited to the properties of the muscle cylinder the 
theory was applicable ; a model could even be -con- 
structed of schematic molecules which displayed all the 
phenomena of the “cylinder” of living muscle ; but in 
the natural muscle certain “ parelectronomic” facts, to 
use du Bois-Reymond’s word, presented themselves, 
which to this day are irreconcileable. 
In connection with the molecular theory of the muscle 
current, he discovered the elementary facts relating to 
what is called stimulation or excitation, viz. that when a 
muscle is excited, whether naturally or artificially, the 
sudden shortening of its fibres is ushered in by still more 
sudden electrical changes. This phenomenon du Bois- 
Reymond succeeded in connecting with those of the 
muscle cylinder by means of the theory above referred 
to. According to his view, when a muscle is excited, 
each of its electromotive elements sustains a diminution 
of its E.M.F., the result of which is that in the muscle 
cylinder so excited the pre-existing difference between 
its cut-surface and its natural surface diminishes. Here 
again the progress of investigation has shown that while 
some of the electrical phenomena of excitation require 
such a theory for their explanation, it does not cover the 
whole ground; for which reason many physiologists 
decline to assign to it its true value. 
A third theory of very wide application relates to the 
way in which electric currents when used as stimuli act on 
nerves. It was recognised by du Bois-Reymond that a 
voltaic current led through a nerve, although it produces 
those remarkable changes in its electromotive properties 
which are called electrotonic, fails to excite it to action 
so long as the current strength remains constant, but that 
the slightest increase or diminution of current strength 
excites it with an intensity which is inversely proportional 
to the time occupied by the change. Under certain 
conditions he found that his experimental results were in 
such strict conformity with the principle laid down as to 
justify their being embodied in a mathematical formula. 
But even here we now know that this “law of excitation” 
is not of universal application. 
We have referred to these instances for the purpose of 
pointing out that du Bois-Reymond’s real greatness con- 
sisted, not in his theories, but in the exactitude of his 
observations, the excellence of the methods which he 
devised, and the number of new relations which he dis- 
covered between physical and vital phenomena. Just as 
Ludwig taught us how to investigate the mechanics of 
the circulation, and Helmholtz how to determme the 
time-relations of physiological processes of very short 
duration, so du Bois-Reymond not only opened to us a 
new field of investigation, but furnished his contem- 
poraries and successors with the means of cultivating it. | 
For this service we can best show our gratitude by 
Striving to work as he did, never allowing theory to in- 
fluence our judgment in the interpretation of experimental 
data, and never contenting ourselyes with inadequate 
methods of observation. In investigations of such diffi- 
culty mistakes are unavoidable, and it cannot be asserted 
that in his fifty years of active work du Bois-Reymond 
neyer fell into any errors of observation ; but if we compare 
these with the new truths which he brought to light and 
established, their importance seems indeed trivial. There 
can be no more striking proof of the solidity of his achieve- 
ments than the fact that, notwithstanding the large number 
of active workers who, during the last few decades, have 
been engaged in physiologieal researches, the instruments 
and methods which he devised are still in use. In every 
laboratory you find his “ Schlitten inductorium,” his non- 
NO. 1419, VOL. 55] 
polarisable electrodes, the du Bois key, and the du Bois 
compensator. 
Like other great teachers, du Bois-Reymond founded a 
school ; although his pupils were far from being as nume- 
rous as those of Ludwig, they occupy very important 
academical positions. The man who probably has done 
more to maintain the influence of his doctrines than any 
other is Prof. Bernstein, of Halle, whose ‘“ Untersuchung 
iiber den Erregungsvorgang,” published in 1871, was 
comparable in importance to that of Hermann’s research 
on muscle physiology, published a few years earlier. It 
is noteworthy that each of them dedicated his research 
to du Bois-Reymond—the one afterwards to become his 
energetic opponent, the other then and now his cordial 
supporter. If on any one the mantle of du Bois-Rey- 
mond falls, it must be on Bernstein. 
J. BURDON-SANDERSON. 
NOTES. 
Tue elevation of Sir Joseph Lister to the Peerage is a New 
Year’s honour which has been received with the keenest satis- 
faction in the scientific world. It may be taken as an acknow- 
ledgment by the Crown of the high position of the President 
of the Royal Society, as well as a recognition of the life-long 
work in science which led to Sir Joseph Lister’s selection for 
that honoured Presidency. 
AN address of congratulation, signed by a number of eminent 
men of science, and by leaders in other branches of learning, 
| has been presented to Mr. Herbert Spencer, in recognition of 
the successful completion of his ‘‘System of Synthetic Phil- 
| osophy.” With reference to this work it is remarked in the 
address: ‘* Not all of us agreeing in equal measure with its 
conclusions, we are all at one in our estimate of the great intel- 
lectual powers it exhibits, and of the immense effect it has pro- 
duced in the history of thought.” The signatories requested 
Mr. Spencer to permit them to employ some eminent artist to 
take his portrait, with a view to its being deposited in one of 
the national collections. Though at one time averse to a pro- 
posal of this kind, Mr. Spencer has now given his consent in a 
letter to Sir Joseph Hooker, who forwarded the address, and 
Mr. THerkomer, R.A., has undertaken to paint the portrait. It 
is gratifying to know that the country will possess an authentic 
personal likeness of so distinguished a philosopher. Donations 
for the portrait fund may be sent to the Bank of England, 
Burlington Gardens, W. 
Tue distinguished Berlin astronomer, Prof. Dr. Arthur 
Auwers, has received from the German Emperor a gold medal 
for his services to science. 
M. CALLANDREAU, professor of astronomy at the Paris Ecole 
Polytechnique, has been elected a Correspondant of the St. 
Petersburg Academy of Sciences. 
Tue Council of the British Institute of Public Health have 
awarded the Harben medal for 1897 to Prof. M. von Petten- 
kofer, Emeritus Professor of Hygiene in the University of 
Munich. 
Iv is understood that Mr. Herbert Goss and the Rev. Canon 
Fowler, who have been joint Secretaries of the Entomological 
Society for the past eleven years, do not intend to offer them- 
selves for re-election at the next annual meeting of the Society 
on the 2oth inst. 
WE regret to announce the deaths of Dr. Luigi Calori, pro- 
fessor of anatomy in Bologna University; Dr. G. D. E. 
Weyer, professor of mathematics and astronomy in the Univer- 
sity of Kiel; M. Vivien de St. Martin, renowned for his re- 
searches in ancient geography ; and Mr. Theodore Wormley, of 
Philadelphia, well known as a chemist. 
