152 Mayow 



directed are so agitated that the nitro-aerial particles 

 which they contain (for we have shown elsewhere 

 that rigid bodies such as iron, abound in nitro- 

 aerial particles) are greatly disturbed and thrown into 

 a fiery motion, and in consequence of this movement 

 of the particles the structure of the substances in 

 which they reside is destroyed. And the more solid 

 bodies are, and the more they abound in nitro-aerial 

 particles, the more quickly are they consumed when 

 struck by lightning ; for the particles of the more 

 solid body strike more violently against one another, 

 and agitate themselves the more. Hence it is that 

 the iron is melted by lightning while the scabbard, on 

 account of its loose texture and the want of nitro-aerial 

 particles, remains uninjured. Thus the very strength 

 of bodies tends sometimes to their destruction and the 

 strongest things perish the sooner from internal dis- 

 cords and movements. 



It is also noteworthy that animals are often killed by 

 lightning without showing any trace of a blow. This 

 seems to be due to the fact that aerial particles — not 

 those alone which are disseminated through the air, 

 but those also which exist in the mass of the blood — 

 are thrown by the violent concussion of the air into a 

 kind of flash, in consequence of which they immedi- 

 ately become effete and altogether unsuitable for 

 keeping up the fermentation of the blood. To this I 

 add that the animal spirits are also dissipated by 

 lightning, as will be shown elsewhere. 



Lastly, with regard to the impetuous and whirling 

 winds which usually accompany thunderstorms, they 

 seem to be caused not merely by the air being 

 violently thrust forth by the pressure of the descend- 

 ing cloud, but also, to some extent, in consequence of a 

 vast tract of air being deprived of its elastic force and 



