16 
about twenty-six inches long and one inch wide, well packed 
with phosphoric anhydride. The evolution flask was con- 
nected by a T piece, with the drying apparatus on the 
one hand, and with a tube dipping under dry mercury on 
the other, the latter serving as a safety valve. The form of 
the apparatus is represented in the diagram. All the joints 
were well secured with thick india-rubber tubing, wrapped 
round with copper wire, and then thickly coated with melted 
paraffin. 
The first metal experimented upon was metallic sodium. 
Freparation of Metallic Sodium . — The following method 
was found to give the best results in preparing clean 
metallic sodium. It is one, however, which requires the 
exercise of patience, because often as many as a dozen of 
the tubes employed break before a successful operation is 
achieved. A clean glass tube, about IJft. long and fin. 
diameter, is drawn out in the following form. This is placed 
vertically in a clamp with the pear-shaped bulb 
downwards. This may be called the bulb end. 
Through the bulb end a current of coal gas is 
passed until most of the air is displaced. A plug 
of glass wool is meanwhile introduced through the 
upper end so as to fall over the constricted part of 
the tube, and above this, pieces of clean dry sodium 
are placed so as to fill about one-half of the upper portion of 
