1 76 Mr. C. Binks on Electricity^ 



number of seconds required for the production of the measure 

 of gas, the greater is the amount of voltaic action. In this in- 

 stance we perceive that the amount is reduced from 85" to 

 160" by the removal from^ of an inch to 10 inches, and then 

 at the latter distance, that the amount is again gradually in- 

 creased by each addition to the size of the copper plate, till 

 it again reaches to 85". It is still further increased by a 

 further addition to the size of the plate; but I here purposely 

 avoid carrying out the numbers beyond the one immediately 

 sought for, namely, the required number, in this instance 85". 

 So soon as that amount is given, I cease to register any 

 further results obtained at that particular position ; for were 

 the results pursued beyond this point, we should then be in- 

 troduced to another series of changes, the consideration of 

 which must be reserved for another section. 



141. But besides that at some distances the action, by this 

 addition to the plate, increases to and beyond the amount re- 

 quired, at others it never reaches that amount ; and when the 

 latter is the case, the trials by the larger plates are carried fully 

 out to discover the number and the size making the nearest 

 approach to the one required. And both the required num- 

 ber, when that is obtained, and where not obtained, that ma- 

 king the closest approach to it in amount, are distinguished 

 by asterisks throughout the tables following. 



142. Now it is seen in this example, that the standard or 

 required amount 85" is obtained (when the plates are 10 inch- 

 es apart,) by a copper plate having a total area of 18 square 

 inches, whilst the same amount is given (at the distance of \ 

 of an inch,) by one whose total area is only 2 square inches. 

 It requires therefore, in this instance, that the copper plate of 

 any couple should be nine times larger to produce at the di- 

 stance of 10 inches, the same amount of action which is pro- 

 duced at I- of an inch. But this example gives the amount 

 obtained for one position only, and under only one general 

 condition of the whole arrangement, though the conditions 

 under which the arrangement may be placed are various. 



143. The first of the succeeding tables will contain the re- 

 sults obtained by testing the operations of an arrangement in 

 this manner at each position, within the range of 12 inches 

 from the zinc, whilst all its attendant conditions remain uni- 

 form ; and such results being obtained fully for any one case, 

 it is then required to find whether, if the acid mixture be al- 

 tered in strength, these results will be altered likewise — in 

 what manner and to what extent; and also, if possible, to 

 discover whether there be any other causes influencing the 

 operations of such arrangements than those originating in 



