On the Effect of Lightning-Stroke 
on Trees. 
BY 
A. W. BORTHWICK, D.Sc, 
With Plates VI. and VII. 
There is a widespread popular belief that certain trees are 
less liable than others to be struck by lightning, and that during 
a thunderstorm it is quite safe to stand under a beech, for 
example, while the danger under a resinous tree or an oak is 
respectively fifteen and fifty times greater. Scattered throughout 
literature are many descriptions of the damage done by lightning 
to single trees and also to groups of trees, but these are confined 
almost without exception to the external appearance of the 
lightning-struck tree ; the internal damage caused by lightning 
has passed without notice. 
In the year 1892 Professor Bayley Balfour exhibited and 
described to the Botanical Society of Edinburgh sections of the 
stem of a lightning-struck oak (Quercus Robur, Linn.), which 
grew in the woods of Methven Castle, Perthshire. One of the 
specimens exhibited is shown in Plate VI. If this figure be 
compared with Plate VII., which shows the damage caused 
to a tree of Q. //ex, and which will be more specially referred 
to later on, it will be seen that the damage in both cases 
is the same. 
In the course of the summer of 1896 the late Professor Robert 
Hartig of Munich* carried out a series of observations on the 
* R. Hartig, Untersuchungen itiber Blitzschlage in Waldbaumen, in Forstl- 
Naturw. Zeitschr. VI (1897), Hefte 3, 4, 5; Id., Neue Beobachtungen uber 
Blitzbeschadigungen der Waldbiume, in Centralblatt fiir d. gesammte 
Forstwesen, August and September, 1899; Id., Schidliche Wirkungen 
des Blitzschlages, Lehrbuch der Pflanzenkrankheiten, 3rd ed., 1900. 
(Notes, R.B.G., Edin., No. XVI, 1905.] 
