234 TRAVELS THROUGH 



LETTER XVII. 



Siena. May 4, 1772. 

 j -\> it 



IG I V E you today an abftracl of my journal 

 from Rome to Siena ; but, mould the fhort- 

 nefs of time not now permit me to take proper 

 notice of the Learned, and their collections, which 

 1 have feen here, I fha'il do it in my next from 

 Florence. The road from Rome to Siena is, for a 

 ftaturalift one of the moft remarkable in Italy. 

 I do not repent therefore having travelled it over 

 a iecond time. 



v A. From P.vme to Viterto I went by the Porta 

 di Popcloj and law the continuation of the above- 

 mentioned calcareous hills and monte Mario, which 

 ran with me to Ponte Mclle or Ewilio, where 

 thefe hills ftretched to the left, and followed the 

 direction of the Tiber. Immediately after Ponte 

 Molle fucceeded volcanic tufo-hilis ; i. Yellow, 

 with fragments of black pumice-ftone, and white 

 farinaceous decayed garnet-like flierls. 2. White- 

 grey corapofed of white puzzohna. 3. Entirely 



whitej. 



