Page:Researches on Irritability of Plants.djvu/115

92 noticeable is the alternating character of the response that took place after the application of alcohol.

The vapour of ether induces a depression of excitability as seen in the diminution of amplitude of response. The first effect of dilute ether-vapour is often a short-lived exaltation. The narcotic effect of this agent on Mimosa is feeble compared with that induced by chloroform. The

depressing effect of ether passes off on readmission of fresh air (fig. 49).

The effect of vapour of carbon disulphide is similar to that of ether. It induces a depression duringr the introduction of vapour into the plant-chamber; the induced depression, however, passes off on restoration by means of fresh air (fig. 50).

Contrary to my anticipation, coal gas proved to be but moderately depressing in its action. I have kept the plant surrounded by this gas for more than two hours