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THOMPSON YATES LABORATORIES REPORT 
section and the artificial transverse section. Very often, indeed, the former appears incomparably weaker; 
and by keeping the frogs for twenty-four hours at least at a temperature of 32° F. (0° C.) it is possible 
wholly to deprive the natural transverse section of its negative power when it is included in a circuit 
with the longitudinal section. But even the direction of the current can be reversed by means of cold. 
Whichever of these various modifications of the electric power of the natural transverse 
section may prevail, the usual current immediately appears when this section is injured in any way, so as 
to deprive an extremely thin layer of its vital properties, and thereby of its electromotive action. 
Since the layer of muscular substance on the natural transverse section tends to reverse the laws of the 
muscular current, Du Bois Rkvmond proposes to call it the parelectronomic layer (from TrapavoiJ.o<; 
contrary to the law), and he likewise calls that the parelectronomic state of the muscle, in which the 
muscle, in consequence of the parelectronomic layer having the intensity of its action increased, either 
appears inactive, or even becomes inactive in the negative direction,' etc. 
Section II. Hermann 
Beginning in 1867, Hermann' produced a series of papers which proved that 
the phenomenon of the current of rest could not be demonstrated in uninjured tissue, 
and that injury, sometimes of an unsuspected kind, was an essential factor in its pro- 
duction. This proof he accompanied by an emphatic and controversial insistence upon 
the importance of the secondary results of injury, and in deference to his views the 
phenomenon has changed name, becoming the current of injury and subsequently the 
demarcation current. The extreme emphasis laid by him upon the secondary results 
of injury has since been abandoned,* and in 1898 he is found deliberating between his 
own ' alteration theory,' which embodies these views, and a ' pre-existence ' theory be- 
longing to that general class of theories against which he so strenuously contended. 
It has been said that Du Bois Reymond's ' peripolar molecule ' was formulated 
upon a basis of assumption, that the matter giving rise to the phenomenon was pre- 
existent and homogeneous. It must also be said that Hermann's 'alteration theory' 
is confessedly based upon an assumption, 2 which must be considered, too, as possibly 
obnoxious ; for it is an assumption of knowledge which is, in this case, unfortunately 
not otherwise attainable. 
' Let us suppose that the dying substance is negative to the living, then all these 
phenomena are explained.' 5 
The acceptance, even temporarily, of such a postulate as this is equivalent to the 
surrender of a legitimate spirit of enquiry, and is impossible to a mind seeking to 
unravel the intricacies of ' vital ' ph enomena by gratefully received details of chemical 
1. Hermann, Untersuchungen %ur Physiologic der Muskeln und Ner-ven. Berlin, 1 867-1 868. 
* See Inter, p. 223. 
2. Hermann, Pfiiigers Archiv., 1898. LXXI, p. 299. 
3. Hermann, Handbuch. Th. I, p. 235. 
Note. — Hermann's alteration theory is expressed in terms of vital states. For a reduction of these to the terms of chemi- 
cal and electrochemical nomenclature — see (1) Bernstein, Pfiugers Archi-v., 1897, who evolves a theory which, superficially similar 
to Du Bois Reymond's in that it is a molecular one, nevertheless involves a chemical difference at the seat of injury and is there- 
fore similar to Hermann's ; (2) Tschagowetz, 1897, Ztscht d. russ Gesellsch f. phys. Chem., XXVII, 5, p. 430 ; (3) Max Oker 
Blom, 1901, Pfugcn Archii:, LXXXIV, p. 191. 
