7S Mr. C. Binks on Electricity, 



action of any arrangement, as position of the plates, agitation 

 of the liquid, adherence of the gas to the plates, pressure of 

 the column of liquid, &c., including the particulars stated in 

 Nos. I., II,, III., XI. and XV, of the above enumeration. 



2nd. Circumstances of a mixed chemical and mechanical 

 kind, affecting the surfaces of the copper plate, as its polish, 

 cleanliness, &c., and stated in Nos. VI. and VII. 



3rd. Circumstances of the same kind, affecting the surface 

 of the zinc, and included in Nos. VIII. IX. and X. 



4th. The temper, or conducting power of the wires and 

 plates, as explained in Nos. IV. and V. 



5th. The influence of the general temperature under which 

 the experiments are performed, as in No. XIV. 



6th. The effects of the weakening and deterioration of the 

 acid mixture in No. XIII. 



7th. The accelerated action occurring upon the zinc in 

 No. Xtl. 



61. To provide against each and all of these interferences, 

 I adopt the following plans throughout the whole inquiry, 

 and which being once distinctly pointed out, need not again 

 be referred to in the course of the subsequent details upon 

 other points, 



62. The zinc plate is removed from the trough at the end 

 of each single experiment, and its surface cleansed by a linen 

 cloth. The copper plate is polished with fine glass paper 

 after each single experiment, washed with a solution of caustic 

 potash, and then well rinsed in acidulated water before its re- 

 turn for the next experiment. The observations of the mea- 

 sure of gas generated in any given time, is not taken till the 

 water has again become tranquil after the motion occasioned 

 by replacing the plates and refilling the meter ; nor till after 

 the complete suspension of the local action which generally 

 takes place upon the first immersion of the zinc. (See 39.) 



The operating plates (unless where it is distinctly stated to 

 the contrary,) have their central points always in one straight 

 line, passing horizontally through the centre of the mass of 

 liquid they are acting in, that in each set of comparative ex- 

 periments the pressure upon the plates may be maintained 

 uniform, and the plates themselves be preserved in a vertical 

 position. The plates of either kind, which are here employed, 

 are cut from the same sheet of metal, the wires from the same 

 coil ; and the whole, after being adjusted, are exposed for some 

 time to a like temperature, so that the temper and conducting 

 power, as far as that depends upon the texture of the metal, 

 may be the same in each. The temperature of the liquid and 

 of the apartment in which the experiments are conducted is 



