6n certain Stony and Metalline Sufrjlances. V? 



From the external characters, and from his analyfis, the 

 profeflbr confiders the ftone of Eniifheim to he ar^illo-ferru- 

 ginous ; and is of opinion, that ignorance and iuperftition 

 have attributed to it a miraculous exiftence, at variance with 

 the firft notions of natural philofophy *. 



The account next in fuccefiion is already printed in the 

 TranfacYions of the Royal Society; but cannot be omitted, 

 as it immediately relates to one of the fubilances I have ex-r 

 amined. I allude to the letter received by Sir William Ha- 

 milton from the earl of Briftol, dated from Sienna, July 12, 

 1794: — " In the midft of a mod violent thunder-ftorm, 

 about a dozen hones, of various weights and dimenfions, 

 fell at the feet of different perfons, men, women, and chil- 

 dren. The itones are of a quality not found in any part of 

 the Siennele territory : they fell about eighteen hours after 

 the enormous eruption of mount Vefuvius ; which circum-r 

 itance leaves a choice of difficulties in the folution of this 

 extraordinary phenomenon, either thefe ftones have been 

 generated in this igneous mafs of clouds, which produced 

 iuch nnufual thunder; or, which is equally incredible, they 

 were thrown from Vefuvius, at a diftanceof at leaft 250 miles; 

 judge then of its parabola. The philofophers here incline to 

 the firft folution. I wifh much, Sir, to know your lentil 

 ments. My firft objection was to the fact itfelf ; but of this 

 there are fo many eye witneffes, it feems impomble to withi- 

 ftaud their evidence." (Phil. Tranf. for 1795, p. 103.) Sir 

 William Hamilton, it feems, alfo received a piece of one of 

 the largeft ftones, which weighed upwards of five pounds ; 

 and had fe^n another which weighed about one. He like*, 

 wife obferved, that the outfide of every ftone which had been 

 found, and had been afcertained to have fallen from the 

 clouds near Sienna, was evidently frefhly vitrified, and was 

 black, having every %*n of having palled through an extreme 

 heat; the infide was of a light gray colour, mixed with black 

 foots and fome fhining particles, which the learned there had 

 decided to be pyrites. 



In 1796 a ftone weighing 56 pounds was exhibited in 

 London, with feveral atteftations of perfons who, on the 

 13th of December 1795, faw it fall, near Wold Cottage, in 

 Yorkfhire, at about three o'clock in the afternoon. It had 

 penetrated through twelve inches of foil and fix inches 

 of folid chalk rock; and, in burying itfelf, had thrown up 

 an immenfe quantity of earth to a great diftance : as it fell, 

 a number of explofions were heard^ about as loud as piftols. 



* See Journal de Pbjjique, Ventofe, an. 8, p. 169. 



In 



