Onthie Itritabtlity of the Stamina of the Barberry. 147 



is in no degree altered in flowers immersed in concentrated in- 

 fusions of narcotic poisons, such as nux vomica, opium, &c. 

 This last fact is in perfect accordance with all that M. Goeppert 

 had previously observed as to the innocuousness of narcotics 

 with respect to vegetation. 



2. In the second series of experiments, M. Goeppert brought 

 the substances, whose influence he wished to determine, into di- 

 rect contact with the stamina only. He found that pure water 

 does not hurt the irritability of the stamina, and that the nar- 

 cotic infusions already mentioned have no prejudicial eff'ect, 

 provided they be deprived of extractive principles. Phosphorus^ 

 dissolved in almond oil, was equally harmless. A drop of prussic 

 acid deposited upon the flower, caused, in ten seconds, a motion 

 of contraction in the stamina towards the pistil. Some hours 

 after, the chemical action of the acid began to manifest itself in 

 the plant by a more or less complete destruction of its parts. 

 The same phenomenon is produced under the influence of alco- 

 hol, ethers, essential oils, aromatic waters, some concentrated 

 acids, &c. None of these substances, however, stimulate the 

 stamina with so much rapidity as prussic acid. It is hardly ne- 

 cessary to add, that these organs lose all irritability in this last 

 act of contraction, and, soon after, are decomposed like the rest 

 of the plant. 



J3. Lastly, M. Goeppert exposed barberry flowers to the va- 

 pours of several volatile substances. Those of the narcotic 

 principles had no action as infusions. The vapours of hydro- 

 cyanic acid, those of mercury in the metallic state, and those of 

 the volatile substances mentioned in the preceding experiments, 

 by destroying the vegetable tissue, also put a stop to the phe- 

 nomena of irritability. 



Chronological Series of the more important Changes made upon 

 the Coasts by the Sea, from the Eighth Century to the pre- 

 sent day. 



Year. 



800 — About this period the sea carried off a large portion of t.lie island of 

 Heligoland, which is situated between liie mouths of the Wescr and 

 the Elbe. 



