12 Mr. Daniell on the Action of Mercury, fyc. 



at the same time combines with the mercury, and a solution is 

 effected by the acetic acid, which its unassisted affinity could 

 not have produced. This action appears to be of the same 

 nature as that described by Mr. Faraday *, in his account of 

 the Alloys of Steel ; during his experiments upon which, he 

 found that steel, alloyed with an hundredth part of platinum, 

 was acted upon by dilute sulphuric acid, with infinitely greater 

 rapidity than the unalloyed steel, and that an acid, which 

 scarcely touched the pure steel, dissolved the alloy with ener- 

 getic effervescence. 



It also appears that this electrical action communicates an 

 adhesive attraction to the particles of the metal, by which the 

 particles of liquid and aeriform bodies are entangled and re- 

 tained, a kind of frothy compound formed, and the fluidity of 

 the mercury destroyed. The appearance of this amalgam is 

 so very like that of the ammoniacal amalgam formed by ex- 

 posing a solution of ammonia in contact with mercury to the 

 influence of the Voltaic pile, or when an amalgam of potassium 

 and mercury is placed upon moistened muriate of ammonia, 

 that it is impossible not to be struck with the resemblance. I 

 am inclined, indeed, to believe, that the production of the latter 

 may be explained upon the same principles as that of the for- 

 mer. When the effect is produced by the direct application of the 

 electrical current, by means of the battery, it ceases the moment 

 the connexion between the poles is broken ; and when brought 

 about by the agency of the amalgam of potassium, the elec- 

 trical action is doubtless excited by the contact of the two 

 dissimilar metals, and the frothy compound lasts no longer than 

 the existence of the potassium in the metallic state. In the 

 action which I have just described, bet ween mercury and finely- 

 divided platinum, the permanence of the metals produces a 

 much more lasting effect, and the soft amalgam may be pre- 

 served for a great length of time without altering its appear- 

 ance. At all events, these results cannot but increase the 

 strong doubts which previously existed concerning the hypo- 

 thesis of the metallization of ammonia, and the supposed 

 compound of mercury and ammonium. 



* Philosophical Transactions) 1822. Part II., p. 262. 



