18 Mr Haidinger an Mesole. 



a perfectly azure sky. Snow lying on the north side of the 

 cone. 



Nov. 30th, Dec. 1st, 2d, 3d, and 4th. — Saw little of the moun- 

 tain. On one day very little smoke, and throughout variable. 



Dec. 5th.— Did not see the hill, but heard that there was 

 much snow on the cool side, and little smoke. 



6th.— -No smoke at all when I saw it, and a great deal of 

 snow, especially on the cone, the north side being completely 

 white. 



7th.— Cloudy all day, and did not see the mountain. 



8th.— Little smoke. 



9th.— The hill clouded till afternoon, when there was a 

 great mass of smoke adhering to the south side of the cone, 

 which seemed unable to rise. 



10th.— Much adhering smoke. 



11th.— In general no smoke, but now and then very slight 

 puffs. 



12th. — The appearance of the mountain towards afternoon 

 was very remarkable, the smoke rising upright in great quan- 

 *tity from the crater, and then spreading horizontally into a 

 light-coloured cloud. Much dense smoke and steam appeared 

 to rise from the north side, which has usually been very quiet ; 

 and whitish vapours from the edges appeared to me to indi- 

 cate the formation of a new crater, and that some of the inte- 

 rior sides were giving way. The afternoon being very clear 

 and cold the mountain was extremely distinct. 



13th.— Both the cone and Monte Somma were almost en- 

 tirely concealed by lateral beds, either of clouds or smoke, 

 but from watching their motion, it seemed rather to be the 

 latter. A 



Rome, January 9} 1827. 



Art. III. — On Mesole. By William Haidingee, Esq. 

 F. R. S. E. &c. Communicated by the Author. 



Sevi£Eal years have elapsed since Berzelius gave the analysis 

 of Mesole, * — a species which he established from specimens 



• Edin. Phil. Journ. vol. vii. p. 7. 



