From the waterproof leather kit slung across his chest, Nessa Vale pulled out three clean glass sample vials fitted with ground-glass stoppers, a brass hydrometer weighted with lead shot, a small pair of nickel tweezers, and a tin box containing strips of parchment dyed with spirit-extract of blue violets.
The air in the wash-out cave was warm, stifling, and thick with an oily, chemical vapor that tasted of burned brass and rotten vinegar. Tomas held the bullseye lantern steady with his sound right hand, resting his left forearm against the cold face of the granite pier to steady his balance in the swirling current. The buckled calfskin brace was wet to the elbow with gray silt. But the leather was stiff and held his scarred wrist firm against the dragging pull of the wastewater. His forearm ached with a dull, throbbing heaviness. The damp underground cold always pierced the old wound tissue, reminding him of his permanent thirty-five percent grip deficit whenever he spent hours wading through icy water.
“Take the sample from the eddy directly beneath the central shear block,” Tomas said. He watched the yellow froth that gathered in the lee of the cantilevered cut stone. “That’s where the solution is most active.”
