Natural History. 191 



have proposed a prize of 300 francs for the l)est answer to the 

 queries, " What are the origin, the causes, and the nature, of 

 the yellow fever ?" " What are the means to prevent it ?" 



§ II. Mineralogy, Geology, Meteorology, &c. 



1. New Mineral Substance. — Mr. J. Deuchar found, a few 

 weeks ago, a new mineral substance imbedded in lime- 

 stone. It melts at a candle, and burns on a wick, or on paper. 

 In the cold it is insoluble in alcohol, potash, or oil of turpen- 

 tine, nor is it acted upon in the cold after five days' exposure to 

 sulphuric, muriatic, or nitric acids. — Annals of Philowphy, ii. 

 p. 236. 



2. Remains of Art in a Limestone Formation. — The following 

 geological fact is stated by Professor Silliman, as translated 

 from Count Bournon's Mineralogy : 



During the years 1786, 7, and 8, they were occupied near Aix, 

 in Provence, in France, in quarrying stone for the rebuilding, 

 upon a vast scale, of the Palace of Justice. The stone was a deep 

 grey limestone, and of that kind which are tender when they come 

 out of the quarry, but harden by exposure to the air. The strata 

 were separated from one another by a bed of sand, mixed with 

 clay, more or less calcareous. The first which were wrought pre- 

 sented no appearances of any foreign bodies, but after the work- 

 men had removed the first ten beds, they were astonished when, 

 taking away the eleventh, to find its inferior surface, at the 

 depth of forty or fifty feet, covered with shells. The stone of 

 this bed having been removed, as they were taking away the 

 sand which separated the eleventh bed from the twelfth, they 

 found stumps of columns and fragments of stones half wrought, 

 and the stone was exactly similar to that of the quarry. They 

 found moreover coins, handles of hammers, and other tools, or 

 fragments of tools, of wood. But that which principally com- 

 manded their attention was a board, about an inch thick, and 

 spven or eight feet long ; it was broken into many pieces, of 

 which none were missing, and it was possible to join them again 

 one to another, and to restore its original form, which was that 

 of the boards of the same kind used by the masons and quar- 

 rymcn ; it was worn in the same liumner, rounded, and waving 

 on the edges. 



The stones, which were completely or partly wrought, had 

 not at all changed in their nature, but the fragments of the 

 board and the instruments, and the pieces of instrumeuts of 

 wood, had been changed into agates, which were very fine. 

 and agreeably coloured. Here then (observes Count Bour- 

 non) we have the traces of a work executed by the hand of 

 man, placed at the depth of fifty feet, and covered with eleven 

 beds of compact limestone ; every thing tended to prove 



