EFFECTS OF DIFFERENT GASES
95
of 15 minutes, proved to be quite ineffective (fig. 54). The action of this gas was so poisonous that restoration of fresh air did not bring about any revival. The plant was subsequently
Fig. 53.—Abolition of excitability under the action of ammonia.
Fig. 54.—Total abolition of excitability and death of plant under the action of sulphuretted hydrogen.
found to have died under the poisonous effect of this gas.
Nitrogen Dioxide
Nitrogen monoxide or laughing-gas has but little effect: there may, however, be a slight excitatory action. Nitrogen