from The Century Dictionary and Cyclopedia
- n. The water containing solid matter in solution which is obtained on boiling meat scraps, slaughterhouse offal, and mixed city garbage containing such materials, the melted grease being skimmed off from the surface and the undissolved solids allowed to deposit at the bottom of the tank. The residue left on evaporating tank-water is called stick. See stick, 4, and tankage, 3.
Sorry, no etymologies found.
So we moved on, having secured enough fresh-water ice to supply a pleasant change after the somewhat discoloured tank-water then being served out.
However, always check for two things in your toilet tank to make sure you have the proper water spot in your bowl: Make sure the tank-water level is set to the manufacturer's "water line" mark inside the tank.