of Serpentine, SfC. in the Apennines. 175 



the history of these rocks would be without interest to sci- 

 ence- but because I was unable to observe them with suffi- 

 cient care, and as it is not necessary for my principal 

 object. 



I ought only to state that at Fontebuona, a col of the first 

 line of Apennines on the side of Florence, on the road from 

 that town to Bologna, the alternation occurs of the greyish 

 fine compact limestone, already described at Rochetta, with 

 the calcareous and micaceous sandstone, which is compact 

 and schistose, an alternating rock not so clearly seen at Ro- 

 chetta. This disposition occurs again at a place named the 

 Maschere, and among the fragments of the sandstone that 

 alternates with the limestone which is brought on the road ; 

 I found one, but only one, that contained some carbona- 

 ceous bodies. 



Shortly afterwards, mounting to the place named lo Stale, 

 Monte Carelli appears a reddish isolated knoll, composed of 

 broken stones aggregated together, without apparent strati- 

 fication, consequently of a true breccia, formed by the 

 union of fragments of red jasper, serpentine, &c.* 



It was, it may be said, announcing the near presence of 



* This knoll, from its form, its isolation, its colours, and the mode of 

 aggregation of the rock composing it, has been taken by Ferber for vol- 

 canic. He does not hesitate to say : 



" The Monte-Traverso is formed of lavas and owes its origin to an 

 ancient volcano " It certainly is not one in the general and received 

 acceptation of that name ; but its appearance is deceiving, and arriving 

 on the spot without recollecting what Ferber had said, we were struck 

 with the same idea, and we could not avoid saying that this hill bore a 

 singular resemblance to the extmguished volcanoes we had seen. 



Ferber is not the only person who has considered that a serpentine 

 rock might be of volcanic origin. 



Guettard had remarked blocks of serpentine between Loretto and 

 Ancona in a formation he considered volcanic. The existence of the vol- 

 canic formation is far from being proved ; but the idea of the association 

 does not the less remain. Sir G. Mackenzie states that the volcanic 

 amygdaloid beds of the mountain of Akkrefell, in Iceland, are traversed 

 by veins of serpentine of more than a metre [about 3 ft. 3j in.] in 

 thickness. Lastly, M. Breislak does not find any reason for excluding 

 magnesian rocks from volcanic products. 



