Huff and Puff Apparatus





This apparatus is used in school biology labs to demonstrate that carbon
dioxide is a product of respiration.A pupil breathes in and out of the
middle tube. The glass tubing is arranged in such a way that one flask
bubbles as the pupils breathes in, the other as the pupil breathes out. A
suitable carbon dioxide indicator, such as lime water or bicarbonate
indicator shows the increased presence of carbon dioxide in the outgoing breath.