336 On Smelting Copper in Japan. 



circuit, is nearly constant, and does not, like mere resistance to 

 conduction, increase in the ratio of the quantity of current. A 

 trifling increase with an increase of the quantity did uniformly 

 manifest itself, but this we imagine is to be attributed rather to 



increased mechanical obstruction from the gas than to any increase 



in the energy of the chemical forces. It may however be in part 

 due to the solution of part of the evolved gases in the liquid, this 

 solution being proportionally less with the stronger currents. 



When in the electrolysis of water acidulated with T ' h of its 

 volume of sulphuric acid the positive electrode was of copper, 

 the resistance to transit was only from ] to j of what took place 

 when platinum formed the positive electrode. With the positive 

 electrode of platinum the apparent resistance to transit was 

 nearly the same whether the negative electrode were of platinum 

 or copper, being apparently a very little greater in the latter case 

 than in the former. In comparing these two cases by the num- 

 bers given by the author, due allowance must be made for the 

 different size of the electrodes used, or we should be liable to 

 overrate the difference fairly attributable to the results. This 

 slight difference of action between the platinum and copper as 

 negative electrodes, (the affinities brought into play in the two 

 cases being the same,) may be referred to the different catalytic 

 action of the polarized platinum and the polarized copper plates in 

 causing the evolution of the hydrogen as gas with greater ease in 

 one case than in the other. Even a greater or less degree of rough- 

 ness of the surface of the electrode appears, according to Mr. Smee, 

 to produce a difference of this kind appreciable without the aid 

 of the nice measures of Mr. Becquerel. Or the difference may on 

 the other hand have been due to difference of temperature or 

 some other circumstance. 



Art. XXIII. — Ko Dou Dzu Roku, or, A Memoir on Smelting 

 Copper, illustrated with plates. Small folio, pp.520. Trans- 

 lated from the original Japanese. * 



The Ko Dou Dzu RoJcu, which we present our readers in an 

 English dress, is a thin pamphlet of twenty leaves, fourteen filled 

 with plates and explanations written in the Japanese hirakana 

 character, and six with Chinese writing. There is neither pre- 

 face nor exordium to the work, which being a very commend- 

 able example, we shall follow, premising that throughout the 

 translation, the original is indicated by marks of quotations. y& 

 will, however, just add a record of our hesitancy in presenting 

 this performance to our readers. The natives who have acted as 



* From the Chinese Repository, 1840. 



