404 AMALGAMATION. 
having been effected by the admirable method of spectrum analysis. 
The patentee, who might safely rest his name on this one discovery 
alone, is otherwise a chemist of high-standing and accredited ability, so 
that we may, without restraint, bestow on his proposition at least a res- 
pectful attention. As might have been anticipated from the repute of 
its discoverer, the method is, regarding it in the light of a chemical 
proposition, a sound one — more than this, it actually does in practice 
what it undertakes to do. The technical problem, the question of its 
universal fitness, or of its adaptability to particular cases only — these 
and others of like kind, will all require to be settled by actual trials, 
and the process, in this sense, must stand or fall according to its own 
merits. Kefraining from all arguments or commendations, we merely 
add that we look hopefully towards the method of Mr. William Crookes, 
because it appears to us to be actually new, very simple, and based on 
sound chemical principles. 
The new process consists in the addition of the metal sodium to the 
mercury used for amalgamation. For the instruction of junior readers 
it may be explained that sodium is the base of soda, caustic soda con- 
sisting of water and oxide of sodium, nearly in the same way that the 
yellow rust of iron consists of water and oxide of iron. Sodium is a 
silver white metal, rather lighter than water, and so greedy of oxygen 
that it tarnishes in a second of time when exposed to air ; it is otherwise 
so oxidizable that it will take oxygen from almost all its compounds. 
Sodium forms a pasty amalgam with mercury, and a little of this rich 
sodium amalgam is to be added from time to time to the bulk of the 
mercury in the amalgamating machine. The addition of this sodium 
amalgam produces the following results : — 
1. The mercury is rendered more greedy of gold. 
2. Water is gradually decomposed with evolution of hydrogen, thus 
preventing oxidation of all metallic surfaces, while the water is rendered 
alkaline, and what may be called grease-killing. 
3. The iron surface in contact with the mercury, the iron basin of an 
amalgamating pan for example, is actually amalgamated over its whole 
surface, just as a copper plate would be by contact with pure mercury, 
and thus the chance of taking up or retaining gold is enormously 
increased, while the iron, being only amalgamated very superficially, is 
not rotted and disintegrated as a copper plate _would be. 
4. Sulphur compounds are decomposed, a sulphide of sodium passing 
into the solution. Sulpharsenides, as arsenical pyrites, are stated also 
to be decomposed, both copper pyrites and gray antimony ore in contact 
with this sodium amalgam afford immediate evidence of decomposition. 
Whether the pyrites, in common cases and with mills working at the 
ordinary speed, will be all decomposed, and whether the advantages 
resulting in practice from this decomposition will admit of expression 
in dividends, is at present a problem; in short, the merits of this dis- 
