ANOMALOUS ELECTRO-CHEMICAL EFFECTS. 391 



oxide of platinum, and to account for it thus it must be 

 assumed that platinum, like zinc or iron, will decompose 

 water by abstracting its oxygen. 



1 2th. I endeavoured, by working for a long time upon a 

 limited quantity of water very slightly acidulated with sul- 

 phuric acid, to detect some compound which might be formed 

 by the oxygen which disappeared. 



I placed in a small tube OT5 c. i. of distilled water, 

 touched with a rod which had been smeared with sulphuric 

 acid. I continued working on this for a fortnight, averaging 

 five hours a day ; and as the liquid diminished by evaporation 

 I added distilled water which had been recently boiled. No 

 change could be detected in the liquid at the expiration of 

 this period. It gave an acid reaction with test-paper, preci- 

 pitated chloride of barium, and showed no bleaching proper- 

 ties, which I looked for as a result of absorbed oxygen. 



I have applied the expressions positive and negative to 

 the terminals of the secondary coil which bore this relation 

 to each other upon breaking contact of the primary coil : as far 

 as I could ascertain by direct experiment, there was, on mak- 

 ing contact, no spark or decomposition from the secondary 

 coil ; but although from the time which the magnetic coil takes 

 to acquire its magnetism no spark is visible with this appa- 

 ratus on making contact, possibly some slight decomposition 

 might then take place ; this, however, though it is well to 

 notice the point, is immaterial to the consideration of the 

 results detailed in this paper, as, if the currents were in alter- 

 nate directions, the proportions of the gases would be equally 

 exceptional and anomalous. 



I have made many variations of the above experiments, 

 but it would be a needless waste of space to detail them. The 

 following are the general results : 



ist. With distilled water, containing a small quantity of 

 sulphuric acid, there is always a notable excess of hydrogen ; 

 in one case the oxygen was only one-fifteenth of the whole 

 volume of gas evolved. With solution of potash a similar 

 result takes place. 



2nd. When the quantity of acid is increased to the point 

 at which the electrolytic power of the solution is the best, the 



