Measures the uptake of oxygen by an organism during respiration.

The apparatus consists of two stoppered boiling tubes connected by three-way taps to either limb of graduated manometer. One tube holds the organisms and has a syringe for altering the level of liquid in the manometer during setting up. The other tube acts as a control thermo barometer. CO2 given off by the respiring organism is absorbed by potassium hydroxide in the experimental chamber resulting in a change in the level of liquid in the manometer tube.

Comes with wire baskets inside test tubes for supporting organisms. Test tube rack required to hold unit upright.