44 
MR. BIRD ON THE ELECTRO-CHEMICAL INFLUENCE OF 
playing on the surface of the mercury for half an hour, or even longer, before it rose 
to the surface of the fluid. In about eight or ten hours the mercury had swollen to 
double its former bulk, and part of it had actually crept * up the platinum wire to 
the height of 0'3 inch above the level of the other portion, adhering to the wire like 
so much tenacious mucilage. On dipping a piece of turmeric paper into the contents 
of the funnel it turned brown, demonstrating the presence of an alkali. The mercury 
was removed from the little tube as quickly as possible, and poured into distilled 
water, which acted upon it, causing the evolution of hydrogen gas from its whole 
surface, and became alkaline from the formation and solution of the oxide of potas- 
sium or potass. The film of mercury adhering tothe platinum wire remained on it 
for some days, giving it the appearance of having been amalgamated. This experi- 
ment, several times repeated, yielded precisely similar results, from which I think 
that I am justified in stating that potassa can be reduced by means of the feeble 
current elicited by a single pair, or as the positive electrode was formed of an oxidi- 
zable metal, in the opinion of some, perhaps of two pairs of plates. 
16. By submitting in the same apparatus a solution of chloride of sodium to the 
influence of the battery, analogous results were obtained. An amalgam of sodium 
being formed, although a much longer time was required, and the result of the ex- 
periment, although quite decided, Avas by no means so distinct as in the case of the 
reduction of potassium. 
17- But of all the saline solutions that I have yet submitted to experiment, none 
afforded such conclusive and interesting results as those of ammonia. The ammo- 
nium being reduced with almost as much ease as copper or tin, when a solution of 
its chloride (hydrochlorate of ammonia) is submitted to the action of the voltaic cur- 
rent in contact Avith mercury, in the same manner as chloride of potassium or sodium. 
The same adhesion and creeping up of the mercury along the wire (15.) is observed, 
and after a few hours the fluid metal swells to five or six times its former bulk. On 
removing it quickly and drying it, by allowing it to fall on bibulous paper the amal- 
gam of ammonium is obtained of a buttery consistence, possessing a dull silvery 
colour, and yielding a peculiar crackling, or (if I may be allowed the expression) an 
emphysematous sensation to the finger on pressing it : on being immersed in water 
it very slowly gave off* hydrogen, and yielded a solution of ammonia. 
18. By far the most satisfactory method of obtaining this amalgam is by using for 
the negative electrode a piece of platinum wire coiled up at one end, after it has been 
amalgamated by dipping it into the ammoniacal amalgam obtained by the last de- 
scribed process ( 17 -)- A minute quantity of mercury is thus made to adhere to the 
wire, Avhich being connected with the zinc side of the battery, is dipped into a solu- 
tion of hydrochlorate of ammonia contained in the smaller tube of the apparatus used 
in effecting the reduction of silicon ( 7 .). The circuit being completed, a few bubbles 
* This peculiar creeping up of the mercury along the wire does not take place if the little tube holding the 
fluid metal is placed in a vertical position. 
