The Breathing of Plants, or Respiration 65 



by breathing deeply? A plant loses weight and gives off heat 

 in breathing ; it also gets energy to do work. 



Place some peas that have just started germinating in a 

 U-tube. Cork tightly. Place the other end in a glass of 



Fig. 70. — Peas germinating, deprived of oxygen. 



pyrogallic acid and caustic potash (KOH). Since pyrogallic 

 acid absorbs oxygen, the peas are deprived of the gas necessary 

 for respiration. The peas make no further progress in 

 germination. In Fig. 70 the first jar contains water, the 

 second caustic potash, the third pyrogallic acid. 



