240 Existence of electric Currents 



Art. V. Observations on the Existence of electric Currents in 

 vegetable Structures. By Golding Bird, Esq., F.L.S. F.G.S., 

 Lecturer on Experimental Philosophy at Guy's Hospital, &c, 



Perhaps there are few points connected with the history 

 of vegetable physiology of which so little is really known, as 

 that forming the subject of the present observations, which 

 are offered less with the view of increasing our information 

 upon this difficult and obscure matter, than of placing what is 

 already known concerning it in a more generally useful form. 



It has not been unfrequently stated, in botanical works, that 

 certain vegetable productions evolve, at particular periods, so 

 much free electricity as to give off sparks to any conducting 

 body in their neighbourhood. It is a matter of extreme 

 regret to the physiologist that these conditions have been 

 described so vaguely ; for, if they really exist, a knowledge 

 of them would be of the highest interest and importance in 

 physiology. I have not met with many authors who mention 

 this supposed electric state of vegetables at all; and those 

 who do advert to it scarcely devote more than a few lines to 

 its consideration; and the individual species possessing this 

 charge of free electricity are frequently not even mentioned. 

 Thus, in a manual now before me {Resume complet de la Phy- 

 sique des Corps imponderables, par MM, Babinet et C. Bailly, 

 1825), the following are the only observations made on this 

 subject : — " Plusieurs vegetaux donnent, dans certains mo- 

 mens, des etincelles electriques ; c'est un cas tout particulier 



Mammalia could not be transported into it ; or, if they could, gravel and 

 extraneous materials would accompany them, and would " excite suspi- 

 cion and create distrust." Indeed, Mr. Richardson himself states that 

 the interior of the bones fished up on the Whitstable oyster-beds is " still 

 filled with the yellow loam and small flints of the gravel." The probable 

 appearances presented would be these : in the central and tranquil parts 

 of the estuary, the geologist would find shells which are now existing in 

 a perfect state ; and mixed with these would be the " lighter and fragile 

 portions " of the gravel, bones, and London clay shells. The broken con- 

 dition of the latter would excite his suspicions, which would be confirmed 

 as he approached the margin of the estuary. He would there find a 

 shingle beach of various erratic pebbles, and containing entire those bones 

 and shells of which he had before found only small fragments. They 

 would, however, be in general more or less rolled, and easily distinguishable 

 from the Mammalia or Mollusca which were living in a. d. 1837. Rolled 

 masses of London clay would probably occur ; and the shells derived from 

 that formation would often contain portions of it in their interior, different 

 from the more recent matrix in which they were now embedded. All these 

 circumstances would soon lead a geologist to a true conclusion, even if no 

 cliffs of London clay and gravel remained to prove that those formations 

 were anterior and unconformable to the one under investigation. 



