CHEMISTRY. 15 
2. Apparatus for Procuring the Liquid Elements. 
Among the simple substances entering into the composition of our earth, 
and its contents, only two are liquid at ordinary temperatures ; the non- 
metallic bromine, and the metallic mercury. The latter is sometimes found 
native, but more frequently in its combination with sulphur as cinnabar. 
The following method may be employed to separate the metal from the 
sulphur. Mix the cinnabar with iron filings, and place it in an iron retort 
(pl. 30, fig. 25). The retort is then to be brought to a red heat, as in a 
wind furnace (fig. 3). At-this red heat the sulphur combines with the iron 
filings, forming a sulphuret of iron, leaving the mercury in a metallic 
condition to be carried over in the form of vapor into the neck of the retort, 
~and thence to an appropriate receiver. The receiver being kept constantly 
cool, the vapor of the mercury is condensed, and the metal thus obtained in 
its ordinary liquid state. 
3. Apparatus for obtaining the Solid Elements. 
The methods to be employed for separating those elementary bodies which 
are solid at ordinary temperatures, vary very much with the different 
combinations which have to be considered. Only a few of these methods 
of manipulation can be referred to in the following pages. Pi. 31, fig. 8, 
represents the apparatus for obtaining phosphorus. BC is a furnace, into 
which an iron retort, A, may be introduced. The retort must be filled with 
a mixture of charcoal dust and phosphate of lime. This latter salt is 
obtained from burnt bones, by several intermediate stages of manipulation. 
The phosphoric acid at a red heat is decomposed, and the oxygen having 
then a greater affinity for the carbon of the charcoal, forms with it carbonic 
acid and carbonic oxyde, leaving the phosphorus in the form of a vapor, 
which is carried over and condensed in the bent upper tube, b. The end 
of the tube dips a few inches below the surface, ccc, of the water, placed in a 
flask, D, closed above with a cork, through which passes the tube d. The 
phosphorus thus condensed in the tube flows into the water, where it accu- 
mulates at the bottom. Great care is necessary to prevent any access of 
atmospheric air, as the contact of the two would be followed by a combus- 
tion resulting from the combination of the phosphorus with oxygen, and the 
consequent formation of phosphoric acid. The tube d, which, passing 
through the cork, does not reach quite to the surface of the water, serves to 
permit the escape of the various gases, as carbonic oxyde and acid, which 
are formed during the operation. Phosphorus is a non-metallic substance 
having much the appearance of white wax, and requires to be handled very 
carefully on account of its inflammable character. 
Preparation of Sodium. Common salt, rock salt, sea salt, all one and 
the same substance. consist of two simple bodies combined in definite 
proportion, the one a gas, chlorine, the other a silver white metal, sodium. 
445 
