168 Prof. Schojnbein's Discussion of M. Fechner's 



to the same experiments, the circulation of the current has no 

 sooner been interrupted than the iron is acted upon by the 

 copper solution in the usual manner. On using any other 

 aqueous solution of oxi-acids or oxi-salts, which in ordinary 

 circumstances act chemically upon iron, we obtain the same re- 

 sults. Now in accordance with his views, Fechner is forced to 

 admit, in order to account for the inactivity of the metal, that 

 iron by acting as the positive pole of a pile is rendered an elec- 

 tro-negative body. I must confess it appears utterly impossible 

 for me to conceive how the admission of such a state of things 

 can be reconciled to the principles of Volta's theory, and the 

 electro-chemical systems of our days. According to my hum- 

 ble opinion, the very reverse of what is really the case should 

 take place, that is to say, iron performing the function of the 

 positive pole of a pile, ought to become a metal more positive, 

 or what comes to the same, more oxidable than it is in its 

 usual condition. Is it possible that the same particles of a 

 body are at the same time in two opposite electrical states, or 

 can any substance at the same time attract and repel oxy- 

 gen? It is quite obvious that Fechner's assertion implies the 

 admission of such a state of things ; for the disengagement of 

 oxygen from the iron must be considered, according to his 

 views, as the effect produced by two different causes : first by 

 that metal being the positive electrode, and then by its (the 

 iron) being a highly electro-negative body. For my part, I 

 cannot adopt such an extraordinary opinion, and must conse- 

 quently consider as erroneous Fechner's assertion, according 

 to which the peculiar condition of iron depends upon the me- 

 tal having changed what is called its natural electro-chemical 

 relations. 



I certainly do not pretend to know in what manner a cur- 

 rent changes the natural qualities of iron ; but my ignorance 

 on this point does not force upon me a hypothesis so ill suited 

 to the principles of the chemical theory as the one spoken of 

 appears to be, with regard to the voltaic-electro-chemical sy- 

 stem which is maintained by Fechner. 



Before passing to another subject, I have still a remark or 

 two to make respecting the matter in question. If a piece of 

 copper (in the shape of a wire,) and one of inactive iron are 

 connected on the one side with a galvanometer, and on the 

 other with a solution of blue vitriol, the needle will be made 

 to deviate in such a direction as to indicate a current passing 

 from the copper through the fluid into the iron. Such a state 

 of things lasts, however, only for a few seconds, the current 

 quickly changing its direction, and the iron becoming positive 

 with regard to copper. This change occurs at the very same 



