Alkali metal such as sodium within tube 14 is heated to {TAIL ~ a temperature} of {HEAD ~ from about 300 to 1000 degrees C.} by suitable means known in the art 
Alkali metal such as sodium within tube 14 is heated to { TAIL ~ a temperature } of { HEAD ~ from about 300 to 1000 degrees C. } by suitable means known in the art
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH