]40 Dr. C. F. Schoenbein on some 



I am afraid will not be much relished by the majority of 

 chemists, so much the less that oxygen being in a free 

 state seems to have no voltaic action at all upon water*. 

 Extraordinary as the matter in question may appear to be at 

 the first sight, it appears less so, in my opit)ion at least, on a 

 closer inspection of the case. Dumas has shown, and as far 

 as I can understand the subject, in a very satisfactory man- 

 ner, that chlorine is capable of losing altogether its ordinary 

 chemical bearings in replacing the hydrogen which is con- 

 tained in acetic acid. In chlor-acetic acid the element named 

 acts the part of hydrogen so perfectly well, that the com- 

 pound last mentioned has all the essential properties of com- 

 mon acetic acid ; and chlorine is so much masked in chlor- 

 acetic acid, that by means even of the most delicate tests its 

 presence there cannot be made perceptible. Now if chlorine, 

 being contained in different compounds, can exist in states 

 which in a chemical point of view must be considered as be- 

 ing diametrically opposite to each other, if chlorine be apt to 

 lose its ordinary affinities and to acquire new ones, 1 ask 

 why should oxygen, and other bodies also, not be capable of 

 undergoing a similar change of chemical character when they 

 are caused to enter into certain combinations; and why 

 should it be beyond the reach of possibility that the second 

 atom of oxygen contained in the peroxides, differs as to its 

 chemical functions from the oxygen contained in water, and 

 that it is possessed of properties which make it to a certain 

 degree similar to free chlorine, bromine, iodine, &c. with re- 

 gard to its action upon the hydrogen of water ? In support 

 of the view that the same substance is capable of performing 

 very different chemical functions, I cannot omit to allude to 

 the beautiful and interesting researches of Professor Graham 

 on the constitution of salts. That distinguished chemist 

 has rendered it highly probable, if not altogether certain, 

 that water acts in the very same compound very different 

 parts ; and he has demonstrated besides, that substances dif- 

 fering in many respects very widely from that fluid may re- 

 place it, and take upon themselves its different functions. 

 These phaenomena of metalepsy, highly ^^interesting as they 

 are in a purely chemical point of view, appear to me to be 

 still more so in a voltaic one, because they promise to offer 

 the key to the comprehension of many voltaic facts which up 

 to this present moment bear an anomalous character. Though 



* A solution of oxygen in (acidulated) water being separated by apiece 

 of bladder from (acidulated; water containing no oxygen dissolved, did net 

 cause an obvious deviation of the needle when both fluids were connected 

 with a most delicate galvanometer. 



