154 
DISTIL ATION OF MERCURY BY STEAM. 
of water ; the aqueous vapors, charged with mercurial vapor, are 
condensed together in a common refrigeratory, the metal separates 
at the bottom of the receiver, while the condensed water occupies 
the upper part. It is curious to observe the liquid thread which 
flows from the refrigeratory ; two currents or threads are distinguish- 
able, an upperone which is water, and below is the mercurial thread- 
there is a continuous current of both. No concussions occur, and 
the operation goes on as quietly and as easily as the distillation of 
water. 
The apparatus employed by the author in these experiments 
consists of, — 1st, a cast iron cylindrical retort, receiving the 
vessel which contains the mercury; 2ndly, an iron worm, which, 
being heated, the vapor of water circulates in it, and being heated 
to a proper degree, enters the retort, traverses it from one end to 
to the other, the mercury being immersed in it; it then escapes 
with the mercurial vapor, and both are condensed in a refrigera, 
tory. 
The author gives in a series of tables the results which he has 
obtained by a series of experiments relating to the distillation of mer- 
cury, both alone and amalgamated ; he states the quantity of vapor 
necessary, and the economical advantages of the new process which 
he thus details : — 
1. Facility of the operation.— Simple ebullition and the distillation 
of water are substituted for the difficult and dangerous distillation of 
mercury ; in which there is more trouble in managing the fire, more 
danger of breakage of the apparatus, more difficulty in removing 
the metal, more wear in the retort ; whereas, in the new process, the 
temperature is constant and fixed, and much lower than the red heat 
usually employed. 
2. Economy of operation. — One workman alone can manage an 
apparatus charged with J 000 kilogrammes of amalgam; the new 
process is adapted to even larger dimensions. 
3. Economy of Fuel is certain, and practice alone can state the 
amount of it; no useless expenditure of fuel will occur, since the heat 
employed will not be greater than required for the distillation of the 
metal. 
4. Economy of Mercury. — The distillation of 100 kilogrammes 
of silver amalgam occasions the loss of two kilogrammes of mercury. 
There are produced and annually distilled six millions of amalga- 
