^0 Dr Gosse on tlie Baths of St Filijypo^ and the formation 
the diminished density of the atmosphere, will afford an accu- 
rate correction, a few trials may be necessary to determine. Such 
trials besides showing the degree of reliance that might be placed 
on this method of ascertaining elevations, would likewise be use- 
ful in determining the nature and extent of the changes in the 
refractive property of the lower atmosphere, — a subject of most 
essential importance in various trigonometrical operations. 
Liverpool, ^^th November 1811). 
Art. XIV. — Account of a Visit made to the Baths cf St Filip- 
po in Tuscany, with a Description of the Mode of forming 
Stone Medallions in Basso Relievo from the Watei'S of the 
Spring. In a Letter from Dr Gosse of Geneva, to Profes- 
sor Jameson. 
In compliance with your request, I have great pleasure in 
communicating to you an account of a visit I made in the year 
1818 to the baths of San Filippo in Tuscany. I enclose also a 
hasty sketch I made of the surrounding country, and shall sub- 
join a few details of the curious manufacture of stone-casts, 
which has for many years been established there. I regret that 
the shortness of my visit renders my account much less com- 
plete than I could wish, but, in the absence of better informa- 
tion, it may perhaps be acceptable to your readers. 
On the morning of the 21st February 1818, I set out from 
Sienna, and, proceeding through a country consisting mostly of 
jblue argillaceous soil, mixed with sea^shells disposed in hills of 
slight elevation, I reached, towards evening, the foot of Mount 
Amiata, from which the springs that supply the baths originate. 
As we approach the mountain, the features of the country be- 
come more rocky, and the -mountain itself exhibits the characters 
of an extinct volcano, of which more particular details may be 
found in a descriptive tour made several years ago by Professor 
Santi of Pisa. The height of the mountain is very considera- 
ble, and therefore it is seen from a great distance, to the west of 
the road leading from Sienna to Rome. Having travelled some 
miles by the side of its base, I reached at length the torrent of 
