Intelligence and Miscellaneous Articles, 77 



which govern this evolution, and by means of which I have succeeded 

 in reproducing a certain number of mineral substances, and in re- 

 covering lead and silver from their respective ores, without any other 

 employment of heat, except what is required for simple roasting, and 

 even without the intervention of this amount of heat. This last in- 

 vestigation, which has taken several years of constant research, is 

 now terminated, and I propose to lay its results before the Academy 

 very shortly. The experiments have been made upon more than 

 30,000 kilogrammes of ores, not only from Mexico, but from various 

 parts of the globe, and upon a sufficiently large scale to show whether 

 the process is or is not practically applicable. 



My account of the principles which govern the disengagement of 

 electricity in chemical reactions has been generally adopted, but as 

 my experiments have now been published some thirty years, I have 

 thought it advisable, after so long a period, to go over these re- 

 searches again. The apparatus employed was the depolarizing ap- 

 paratus, which I have lately presented to the Academy, and of which 

 I have given a description in this memoir. 



I first attended to the electrical effects produced in the reaction 

 of acid, alkaline or neutral solutions upon water, and upon one an- 

 other, avoiding especially the effects of polarization resulting from 

 products deposited upon the platinum plates intended for the trans- 

 mission of the currents. I arrived at this result, that water is ne- 

 gative in relation to all acids and to saturated solutions of neutral 

 salts and positive in relation to the alkalies ; that in the reaction of 

 acids upon each other, the most oxidizing acids are the most positive, 

 and that the acids, in combination, transmit to their compounds 

 their electro-positive properties, so that when mixed or combined, 

 solutions of nitrates are positive in relation to sulphates, and sul- 

 phates in relation to chlorides. Hence we see why the intervention 

 of nitromuriatic and nitric acids in galvanic batteries produces a 

 greater evolution of electricity than the other acids, as was pointed 

 out by me in 1827, when I described the pile in which each pair was 

 formed of nitric acid, potash and platinum. 



My experiments with the depolarizing apparatus have led me to 

 this general fact : when water and several other neutral, acid or alka- 

 line solutions are in contact (two and two) so as only to combine or 

 mix very slowly, the electrical effect produced is the sum of the 

 individual electrical effects produced at each surface of contact. This 

 is in opposition to the principle advanced by Volta, namely, that 

 when several solid or fluid substances are in contact one after the 

 other, the electrical effects produced are the same as if the two ex- 

 treme substances were immediately in contact. 



The principle which 1 have just indicated leads to this result, that 

 electrical circuits may be formed with liquids alone, as in fact I had 

 shown to be possible in a memoir laid before the Academy in 1847. 

 Similar circuits must also exist in living organized bodies, and hence 

 we may conceive the possibility of the production of electro-chemical 

 effects in organic tissues. In my memoir I have given two examples 

 of currents of this nature, in the stems of vegetables during the 

 movement of the sap, and in the tubers of the potato. 



