SUBTERRANEAN CHEMICAL FORCES. 399 



tine streams of fire. He thought that the vio- 

 lence of the subterranean action might be known 

 from the height to which the vapour and smoke 

 ascended, and by the amount offerilli, or vol- 

 canic lightning. (Philosophical Transactions of 

 the Royal Society, for 1795.) 



Dr. Daubeny further relates, on the authority 

 of M. Monticelli, and other persons who wit- 

 nessed the eruption of Vesuvius in August, 1834, 

 that from a current of lava which overwhelmed 

 one hundred and fifty houses, and covered about 

 five hundred acres of ground, there arose a black 

 cloud, from which emanated very vivid flashes 

 of lightning, sometimes followed by thunder, but 

 not always. (Philosophical Transactions, 1835.) 



It is also related in the American Journal of 

 Science, that on the 20th of January, 1835, Ni- 

 caragua, in central America, was visited by a 

 tremendous earthquake, and followed by an 

 eruption of the volcano of Cosiguina, by which 

 the atmosphere was filled to a great height and 

 distance with phosphoric sand, smoke, and va- 

 pour, from which issued perpetual flashes of 

 lightning throughout the night of the 20th, and 

 the whole of the next day. On the 23rd, 

 towards morning, tremendous loud thunder claps 

 were heard in succession, like the firing of the 

 largest cannon, from which it was supposed by 

 the inhabitants at the Port of Balize, on the 

 Bay of Honduras, that a naval action was going 



