  To elucidate the mechanism as to why alcoholic beverages can induce
superconductivity in Fe_{1+d}Te_{1-x}S_x samples, we performed component
analysis and found that weak acid such as organic acid has the ability to
induce superconductivity. Inductively-coupled plasma spectroscopy was performed
on weak acid solutions post annealing. We found that the mechanism of
inducement of superconductivity in Fe_{1+d}Te_{1-x}S_x is the deintercalation
of excess Fe from the interlayer sites.
