Oji ascending Lightning, 113 



no longer subserve the object for which they have been addu 

 ced, so soon as steam is considered as the possible agent by which 

 tlie process of decortication has been accomplished. 



I may make precisely the same remarks concerning another 

 phenomenon which has been pointed out by observers with the 

 same assiduous care, and which relates to the leaves of those 

 trees that have been struck by lightning. The leaves of the 

 trees at Marsillargues upon the property of M. Mourgues, as 

 also the leaves of the trees in the Champs Elysees, which were 

 examined by M, Marchais, were yellow, crisp, as if roasted, and 

 convex on their under sides, whilst the green surface of the 

 opposite and upper side had not undergone any alteration, ex- 

 cepting only, that their planes, instead of being somewhat con- 

 vex, had become concave, precisely as happens on those sides of 

 sheets of parchment which are turned from the fire. Here, it is 

 maintained, another striking proof is afforded that the flaming 

 current of the lightning passed from below upwards. The 

 movement from beneath upwards seems, in truth, sufficiently 

 established ; but who will venture, in the present state of the 

 inquiry, to affirm that the ascending current was not produced 

 by steam at a high temperature, probably not saturated, and re- 

 sulting from the evaporation produced by the agency of a de^ 

 scending Jlash ()/' UgJdning acting upon the humidity of the 

 soil ? Finally, we might have recourse to the same agency of 

 steam in explaining how, at the foot of trees that have been 

 struck, we often find the sod turned over, and sometimes opened 

 up at either side of the laceration of the soil, like the leaves of 

 an open book. 



In thus prosecuting this minute discussion, I have endea- 

 voured to demonstrate that the facts, upon which many natural 

 philosophers believe that they have established the existence of 

 ascending lightning, do not confer upon their labours the cha- 

 racter of true demonstrations. I shall, however, moreover add, 

 that the question appears to me completely settled by the whole 

 of the circumstances of a melancholy event which took place 

 near Coldstream, in Scotland, and which are detailed in another 

 part of this essay. I unreservedly admit, then, the existence of 

 ascending lightnings, I know well that natural philosophers of 

 the highest character disbelieve in them ; I also know that they 



VOL. XXVI. NO. LI. JANUARY 1839- ' H 



