what is the historical story of this?
In medieval Europe, a compound of sodium with the Latin name of "sodanum" was used as a headache remedy.
Sodium
 In medieval Europe, a compound of sodium with the Latin name of "sodanum" was used as a headache remedy. 
na is the symbol for which of the following chemical elements Sodium
wiki:25611815
Sodium [SEP] History
Because of its importance in human health, salt has long been an important commodity, as shown by the English word "salary", which derives from "salarium", the wafers of salt sometimes given to Roman soldiers along with their other wages. In medieval Europe, a compound of sodium with the Latin name of "sodanum" was used as a headache remedy. The name sodium is thought to originate from the Arabic "suda", meaning headache, as the headache-alleviating properties of sodium carbonate or soda were well known in early times. Although sodium, sometimes called "soda", had long been recognized in compounds, the metal itself was not isolated until 1807 by Sir Humphry Davy through the electrolysis of sodium hydroxide.