254 EXPERIMENTAL INVESTIGATIONS. 



of tubes containing strips of platinum foil covered with a pul- 

 verulent deposit of the same metal ; the platinum passed 

 through the upper parts of the tubes, which were closed with 

 cement, the lower extremities were open ; they were arranged 

 in pairs in separate vessels of dilute sulphuric acid, and of each 

 pair one tube was charged with oxygen, the other with hy- 

 drogen gas, in quantities such as would allow the platinum to 

 touch the dilute acid ; the platinum in the oxygen of one pair 

 was metallically connected with the platinum in the hydrogen 

 of the next, and a voltaic series of 50 pairs was thus formed. 

 With this battery the following effects were produced : 



r. A shock was given which could be felt by five persons 

 joining hands. 



2. The needle of a moderately sensitive galvanometer was 

 whirled round and remained permanently deflected 60. 



3. A gold-leaf electroscope was notably affected. 



4. A brilliant spark visible in broad daylight was given 

 between charcoal points. 



5. Iodide of potassium, hydrochloric acid, and water acidu- 

 lated with sulphuric acid were severally decomposed ; the gas 

 from the decomposed water was collected and detonated. The 

 gases were evolved in the direction which the chemical theory 

 would indicate, the hydrogen travelling in one direction 

 thoughout the circuit, and the oxygen in the reverse. 



When distilled was substituted for acidulated water in the 

 battery cells the effects were similar but more feeble. 



The effects, though clear and decisive in themselves, were 

 further tested by counter-experiments, such as reversing the 

 current by reversing the gases, &c. ; but these I need not here 

 detail, as the electrical effects of the gas battery, when charged 

 with oxygen and hydrogen, have since the publication of that 

 paper been repeatedly verified. I farther stated, that when 

 carbonic acid and nitrogen were substituted for oxygen and 

 hydrogen no voltaic effects were produced ; that oxygen and 

 nitrogen produced no effects, but that hydrogen and nitrogen 

 did produce a voltaic current, which I attributed to the com- 

 bination, with the hydrogen, of the oxygen of atmospheric air 

 in solution. This opinion will be further tested in the following 

 paper. 



