in vegetable Structures. 241 



de rupture d'equilibre des fluides : on observe surtout ces 

 phenomenes dans la capucine et dans \efraxinelle" (p. 73.) 



Capucine, it appears, is the French name of the common 

 garden nasturtium (Tropse v olum majus Lin.), of the electrical 

 properties of which I must confess my entire ignorance. The 

 fraxinelle, or Dictamnus albus, is stated, by other authors be- 

 sides those above referred to, to evolve free electricity. I am 

 not acquainted with any facts in support of this opinion, or 

 with any experiments which appear to countenance it; al- 

 though I think that the following observation of Professor 

 Lestiboudois will assist in throwing some light on this sup- 

 posed property of the Dictamnus, and serve, in some man- 

 ner, to explain the circumstance to which the opinion of its 

 electric properties is indebted for its origin : — " Dans les 

 temps chauds, la fleur (de la fraxinelle) repand une vapeur 

 inflammable en si grande abondance, que si on en approche le 

 soir une bougie allumee, il paroit une jlamme qui ne Vendom- 

 mage point" (Botanog. Belgique, t. ii. p. 140.) 



To turn from this vague and unsatisfactory part of my 

 subject to one far more interesting, I would refer to some 

 experiments of an exceedingly talented philosopher, Dr. 

 Donne, who has devoted some time to the detection of elec- 

 tric currents in organic tissues, and has succeeded in de- 

 monstrating their existence in both animal and vegetable 

 structures. These currents are exceedingly feeble, and, of 

 course, of very low tension, as must necessarily be the case ; 

 for, if of considerable intensity, it is evident that they could 

 not be insulated by organic tissues, especially when moistened 

 by their proper juices; but would escape, as soon as formed, 

 to the earth, through the stem, which is always a sufficiently 

 good conductor for this purpose. This circumstance, I may 

 observe, en passant, militates most strongly against the pro- 

 bability of living vegetable tissues ever (unless by artificial 

 means) becoming so charged with electric matter as to afford 

 a spark, as stated by Babinet and Bailly. 



M. Donne inserted two pieces of platinum wire, connected 

 with a very delicate galvanometer, into different kinds of 

 fruits, one wire being always inserted near the apex, and the 

 other near the base, of the fruit : a deviation of the magnetic 

 needle always ensued, in different degrees, according to the 

 kind of fruit; sometimes even extending to 30°. In apples 

 and pears, the current of electricity appeared to be directed 

 from the base to the apex of the fruit ; whilst in peaches, apri- 

 cots, and plums, the current assumed an inverse direction. 

 No current whatever could be detected when the platinum 

 wires were plunged into the fruit at equal distance from the 



Vol. I. — No. 5. n. s. t 



