Abstract: A self-cleaning multistage bird feeder having a plurality of truncated hollow cones or funnels stacked vertically end to end. The truncated cones are stacked large end up with adjacent cones being spaced apart to define a plurality of annular feeding troughs. The feeder includes a cover over the uppermost cone and a disc under the lowermost cone. Perches extend outwardly from the cones and the disc. Bird food consequently travels downward through the feeder due to the feeding action of the birds. Bird food is purged from the bottom of the feeder and spills onto an apertured tray suspended under the disc. Additionally a hopper type feeder comprising a single truncated hollow cone or funnel, cover, disc and apertured tray wherein the disc provides a self cleaning platform feeding area and the disc and suspended tray provide superior viewing of feeding activity compared to conventional hopper type feeders.

Abstract: A process for reducing the chemical oxygen demand of water removed from a mixture of crude tetrahydrofuran and water, said process comprising contacting said mixture in the vapor phase with a dilute sodium hydroxide solution, then optionally contacting the tetrahydrofuran-water mixture after condensation with a concentrated sodium hydroxide solution and separating water from the thus treated mixture, said water having reduced chemical oxygen demand over water that is removed from said mixture merely by distillation.