on certain stony and metalline Substances , See. ijg 
From the external characters, and from his analysis, the 
Professor considers the stone of Ensisheim to be argillo-ferru- 
ginous ; and is of opinion that ignorance and superstition have 
attributed to it a miraculous existence, at variance with the first 
notions of natural philosophy.* 
The account next in succession is already printed in the 
Transactions of the Royal Society ; but cannot be omitted, as it 
immediately relates to one of the substances I have examined, 
I allude to the letter received by Sir William Hamilton, from 
the Earl of Bristol, dated from Sienna, July 12th, 37 94. “ In 
“ the midst of a most violent thunder-storm, about a dozen 
“ stones, of various weights and dimensions, fell at the feet of 
“ different persons, men, women, and children. The stones are 
“ of a quality not found in any part of the Siennese territory ; 
“ they fell about eighteen hours after the enormous eruption of 
“ Mount Vesuvius ; which circumstance leaves a choice of dif- 
“ Acuities in the solution of this extraordinary phenomenon. 
“ Either these stones have been generated in this igneous mass 
“ of clouds, which produced such unusual thunder; or, which is 
“ equally incredible, they were thrown from Vesuvius, at a 
“ distance of at least 250 miles ; judge then of its parabola. 
“ The philosophers here incline to the first solution. I wish 
“ much. Sir, to know your sentiments. My first objection was. 
“ to the fact itself; but of this there are so many eyewitnesses, 
“ it seems impossible to withstand their evidence.” (Phil. Trans, 
for 1795. p. 103.) Sir William Hamilton, it seems, also, 
received a piece of one of the largest stones, which weighed 
upwards of five pounds ; and had seen another, which weighed 
about one. He likewise observed, that the outside of every stone 
which had been 1 ound, and had been ascertained to have fallen; 
* See Journal de Physique. Ventose , An 8. p, 169. 
