96 PHYSICAL SCIENCE BK. n 



concern us ; for instance, whether the same kind of 

 lightning as has occurred will again occur in the 

 same year. Sometimes lightning contains no indi 

 cation at all, or one whose grasp eludes us ; as, for 

 example, those manifestations of it that are scattered 

 through the spaces of the sea or in lonely deserts. 

 Their indication, if any, is lost. 



LII 



1 I HAVE still a few remarks to add in order to show 

 more fully the force of lightning in various ways, 

 for its power is not always displayed in just the 

 same way in every kind of material. For instance, 

 the stronger bodies are shattered with greater 

 violence on account of their resistance ; it some 

 times passes through the yielding ones without 

 doing any damage. With stone and iron and all 

 the hard substances it enters into conflict, because 

 in its impetuous course it must find a way through 

 them ; so it makes a way by which to escape. The 

 more flexible and thinner substances, though they 

 seem very suitable material for flames, it spares, 

 mitigating its fury when it encounters no obstacle 

 to its passage. And so, as I said at a previous 

 point, coin is found fused, while the purse that 

 contained it is untouched ; the extremely thin fire 

 runs through the invisible interstices of the latter. 

 But whatever solidity it meets in a beam it subdues 



2 as being refractory. For, as I have just said, its 

 fury does not always take the same form ; the 

 nature of the force in each case is revealed merely 

 by the kind of the damage, and you can tell the 

 species of the lightning by its effect. Again, the 



