3 
recorded by Sir Wni. Hamilton that jets of it were thrown 
from Vesuvius in 1779 to a height of 10,000 feet. This 
spreads out in the atmosphere and is often carried by the 
wind to great distances. In 1845, during an eruption of 
Hekla in Iceland, dust was deposited in the Orkneys and 
Shetland, a distance of 500 miles, in 10 hours. 
The finest particles are carried the greatest distance; 
thus whilst stones of 8 pounds weight are found in Pompeii 
at the foot of Vesuvius which helped to bury the city in 
the year 79 none are found of a greater weight than 1 ounce 
at Castellamare, the ancient Stabioe, 10 miles away. It is 
recorded, however, that the north wind, which was then 
blowing, carried the dust into Africa. 
I exhibit a specimen of dust collected by my friend Mr. 
Morton, who has just returned from New Zealand. It was 
gathered 45 miles from the volcano and is in a fine state of 
division. It contains Felspars, Magnetite, Olivine and 
Augite, 
Soluble in water 0’74% 
Soluble in Hydrochloric Acid 11 *94% 
The proportions of its constituents are : 
Silica 54-03 
Alumina 15*98 
Oxides of Iron 13*02 
Lime..... 8*37 
Magnesia 3*78 
Soda 2*34 
Potash 0*78 
Phosphoric Pen toxide 0*64 
Loss on Heating 0*87 
Sulphuric Acid \ 
Chlorine, Manganese > traces. 
Titanium ) 
It is evident from the above, and the finely divided state 
of the ash, that by its decomposition the Potash, Soda, Lime, 
Magnesia and Oxide of Iron will be set free as Phosphates, 
