Page:Researches on Irritability of Plants.djvu/120

Rh of the motile excitability of pulvinus. Excitability is restored under application of glycerin.

Ozone enhances the excitability of Mimosa.

Carbonic-acid gas and vapour of alcohol induce a moderate depression of excitability, which is fully restored on admission of fresh air.

Depression of excitability is also induced under the action of coal gas, and vapour of carbon disulphide.

The vapour of ether exerts a moderate narcotic action. The effect of vapour of chloroform is very pronounced, loss of excitability under its action being prolonged.

Ammonia induces a marked abolition of excitability.

Sulphuretted hydrogen, nitrogen dioxide, and sulphur dioxide abolish the excitability and bring about the death of the plant.