324 M. Becquerel on the Relations of Natural Philosophy 



sists in combining this metal with quicksilver, without the aid 

 of heat, in a set of operations which has undergone few changes 

 since the middle of the sixteenth century, the epoch of its dis- 

 covery, and the theory of which is even now far from being 

 well known. The amalgam is separated from the mineral by 

 washing, and the silver from the mercury by heat. The amal- 

 gamation is effected in a viscous magma or lie, composed of the 

 silvery mineral bruised into an impalpable powder, and likewise 

 of mercury, common salt, sulphate of copper and of iron, of 

 lime and of water, which are left to their mutual spontaneous 

 action, whilst they are moreover frequently kneaded as it were 

 under the hoofs of horses and mules. The different actions 

 which are produced in this magma have been carefully examined, 

 since those principles which were formerly neglected have begun 

 to be studied. Since that time, the different causes which are 

 sometimes opposed to the chloridation of the silver, and to the 

 decomposition of the chloride by the mercury, whence losses 

 sometimes result in the process, have been discovered. By re- 

 moving these disturbing causes, and by reducing the problem, 

 so to speak, to its most simple expression, silver has been ex- 

 tracted from a great number of ores, without the employ- 

 ment either of heat or of quicksilver, by employing sea-salt 

 only, and some chemical products which are very easily pro- 

 cured every where, and iron, or iron and silver only in such 

 a way that silver is extracted by the silver. All that is re- 

 quired, then, for tlie working of these valuable minerals is, that 

 the localities wiience they are procured be found in the neigh- 

 bourhood of the sea, or of those great collections of rock-salt 

 which are concealed in many parts of the world. 



The first experiments were made in tubes which were al- 

 most capillary, and upon the most minute fractions of the ore. 

 The results have been such, that after a few trials, experiments 

 have successfully been made upon many hundreds of pounds. 

 And it is now hoped that in a very short lime, art will be able 

 to avail itself of a process which, in addition to the pecuniary 

 advantages it affords, will enable us to reduce those valuable 

 ores, which now cannot be subjected either to amalgamation, 

 or to the action of fire, more especially those which contain 

 copper in great quantities, and whose management has always 

 been an impossibility to metallurgists. 



