VOLTAIC SYNTHESIS OF WATER. 249 



by the oxidable than by the inoxidable metals, and to alter 

 their physical characters without materially increasing their 

 weight. On examining papers connected with this subject 

 the author found that Mr. Daniell had cursorily noticed a 

 deposit somewhat analogous to those here treated of, which 

 was formed upon the negative plate of his constant battery, 

 when this was charged on the zinc side with hydrochlorate of 

 ammonia, and the nature of which that gentleman observed 

 was worthy of further examination, but had not had time to 

 investigate. 



SYNTHESIS OF WATER BY VOLTAIC ACTION. 



Philosophical Magazine, Feb. 1839. 



Two strips of platinum, two inches long and three-eighths of 

 an inch wide, standing erect at a short distance from each 

 other, passed, hermetically sealed, through the bottom of a 

 bell glass ; the projecting ends were made to communicate 

 with a delicate galvanometer ; the glass was filled with water 

 acidulated with sulphuric acid, and both the platina strips 

 made the positive electrodes of a voltaic battery until perfectly 

 clean, &c. ; contact with the battery having been broken, over 

 each piece of platinum was inverted a tube of gas, four-tenths 

 of an inch in diameter, one of oxygen, the other of hydrogen, 

 acidulated water reaching a certain mark on the glass, so 

 that about half of the platina was exposed to the gas, and 

 half to the water. The instant the tubes were lowered so as 

 to expose part of the surfaces of platinum to the gases the 

 galvanometer needle was deflected so strongly as to turn more 

 than half round ; it remained stationary at 1 5, the platinum 

 in the hydrogen being similar to the zinc element of the pile. 

 When the tubes were raised so as to cover the plates with 

 water, the needle returned slowly to zero ; but the instant that 

 the tubes were lowered again, it was again deflected ; if the 

 tubes were changed with regard to the platina, the deflection 

 was to the contrary side. 



