By the addition of sodium amalgam to a concentrated solution of ammonium chloride, the so-called ammonium amalgam is obtained as a spongy mass which floats on the surface of the liquid; it decomposes readily at ordinary temperatures into ammonia and hydrogen; it does not reduce silver and gold salts, a behaviour which distinguishes it from the amalgams of the alkali metals, and for this reason it is regarded by some chemists as being merely mercury inflated by gaseous ammonia and hydrogen.
As soon as he was able to work again he attempted to obtain the metals of the alkaline earths by the same methods as he had used for those of the fixed alkalis, but they eluded his efforts and he only succeeded in preparing them as amalgams with mercury, by a process due to Berzelius.
With mercury it forms amalgams. Bismuth is a component of many ternary alloys characterized by their low fusibility and expansion in solidification; many of them are used in the arts (see Fusible Metal).
It also forms amalgams with mercury, and on this account has been employed in dentistry for the purpose of stopping (or filling) teeth.
New amalgams and methods of colouring have been discovered, and fresh forms have been diligently studied.
