of certain Solid and Fluid Substances. 45 



others which are mentioned in the memoir above alluded to, 

 a great number of rather important inferences might be 

 drawn; but having for the present no leisure time to do so, 

 I am obliged to confine myself to stating those which follow: 



a. The secondary currents produced both by polar wires, 

 electrolytic fluids, and secondary piles, are due to chemical 

 action, i. e. (in the cases mentioned) to the union of oxygen 

 with hydrogen, or to that of chlorine with hydrogen ; and not, 

 as M. Peltier seems to think, to the mere act of the solution 

 in water of the gases mentioned. 



h. The chemical combination of oxygen and hydrogen in 

 acidulated (or common) water is brought about by the pre- 

 sence of platina in the same manner as that metal determines 

 the chemical union of gaseous oxygen and hydrogen. 



c. The current produced by a platina wire being sur- 

 rounded by a film of chlorine, or by water holding chlorine 

 in solution, is not dependent on the action of the latter body 

 upon platina, but on the action of chlorine upon the hydrogen 

 of water. 



d. Electrolytic bodies do not suffer even the weakest cur- 

 rent to pass through them without undergoing decomposition. 

 (This inference is drawn from the fact ascertained by me 

 some time ago, that platina wires acting as electrodes in mu- 

 riatic acid are polarized by a current so weak as not to be 

 able to electrolyze even iodide of potassium). 



c. The most delicate test to ascertain that electrolyzation 

 has taken place, is the polai'ized state of the electrodes. 



I cannot close my letter. Gentlemen, without taking the 

 liberty to point out to you the beautiful, and, as it seems to me, 

 most conclusive evidence in favour of the correctness of the 

 chemical theory of galvanism, now so much contested, which 

 is afforded by the fact stated in § 10. If the mere contact 

 of the two different fluids mentioned there were the real cause 

 of the current obtained, it is obvious that the same current 

 ought to be produced whether the fluid be connected with 

 the galvanometer by means of gold, or if they be connected 

 widi the instrument by that of platina wires ; but the result 

 being determined by the nature of the connecting wires, and 

 platina being known to favour the union of hydrogen and 

 oxygen, whilst gold and silver do not possess in any sensible 

 degree that property, we are entitled to assert that the current 

 in question is caused by the combination of hydrogen with (the) 

 oxygen (contained dissolved in water) and not by contact. 

 I am, Gentlemen, yours, &c. 



Bale, Dec. 183«. C. F. ScHOiNBEIN. 



