After the midday meal, they began. The apparatus was set up in feverish haste. In a cubic vat, a foot each way, a saturated solution of Ammonaline was poured. An old, battered spoon was the cathode and a mass of ammonium amalgam (separated from the rest of the solution by a perforated glass partition) was the anode. Three batteries in series provided the current.

Sills explained animatedly, “It works on the same principle as ordinary copper plating. The ammonium ion, once the electric current is run through, is attracted to the cathode, which is the spoon. Ordinarily it would break up, being unstable, but this is not the case when it is dissolved in Ammonaline. This Ammonaline is itself very slightly ionized and oxygen is given off at the anode.

“This much I know from theory. Let us see what happens in practice.”

He closed the key while Taylor watched with breathless interest. For a moment, no effect was visible. Taylor looked disappointed.