1 



192 COMMUNICATIONS BY 



this way, the gas, without passing through water, or being 

 brought in contact with any external agent, continued to be 

 supplied to the jar, until the entire atmosphere above the solu- 

 tion consisted of oxygen alone, when the metallic plug was 

 deposited instantly in the neck of the jar, so as to cut off all 

 communication with the external air. The open vessel or 

 tumbler being now placed by the side of the close apparatus, 

 and four ounces of the solution before mentioned having been 

 poured into it, the necessary communication between the two 

 vessels was effected by means of suitable wires, and contact at 

 the same time similarly established with the respective poles of a 

 constant battery of ten pairs. By means of this arrangement, 

 the current entered the open vessel first, and then proceeded, 

 through the solution in the close apparatus, in its way to the 

 negative side. 



I must here remark that the electric current, immediately on 

 its first application, was observed to decompose the solution with 

 such energy, that I deemed it advisable to suspend the operation 

 until the activity of the battery should be somewhat modified, 

 and it was not until the evening of the 6th of May that I could 

 date the commencement of my experiment. 



A circumstantial record of all important changes connected 

 with this experiment has been preserved, up to the present day, 

 embracing a period of three years and three months, but I can- 

 not conclude that any extracts from my memoranda would 

 enhance the interest of the present notice. I shall therefore 

 prefer a brief summary of the results ; first premising that two 

 excellent constant batteries have been successively worn out in 

 the undertaking, and that the requisite changes were made with- 

 out interruption to the electric current, which is now transmitted 

 by a water-battery of twenty pairs, working with the charac- 

 teristic uniformity of this excellent species of voltaic contrivance. 

 I would further remark that, from the commencement of the experi- 

 ment, the battery and the respective vessels containing the solutions 

 have been strictly excluded from the light, by means of a screen 



