Mr. Davy’s Lecture on some 
1 6 
fusion with boracic acid : it had afforded in 100 parts parts of 
soda, and nearly \ a part of muriatic acid, with 15 parts of lime. 
This stone appeared to me very well fitted for the purpose 
of experiment : cavities were drilled in two pieces, properly 
shaped; they contained about 12 grains of water each; they 
were connected by moistened amianthus, and the process con- 
ducted as usual with a power of 50 pairs of plates. At the 
end of ten hours the result was examined with care. The 
fluid that had been positively electrified had the strong smell 
of oxymuriatic acid, and copiously precipitated nitrate of 
silver ; the other portion of fluid affected turmeric, and left 
by evaporation a substance which seemed to be a mixture of 
lime and soda, 
A part of a specimen of compact zeolite, from the Giant’s 
Causeway, which by analysis had given 7 parts in 100 of soda, 
had a small cavity made in it ; it was immerged in pure water 
in a crucible of platina, and electrified in the same manner 
as the cube of Carrara marble, mentioned in page g. In less 
than two minutes the water in the cavity had gained the pro- 
perty of changing the colour of turmeric ; and in half an hour 
the solution was disagreeably alkaline to the taste. The 
matter dissolved proved to be soda and lime. 
Lepidolite, treated in the same way, gave potash. 
A piece of vitreous lava, from Etna, gave alkaline matter, 
which seemed to be a mixture of soda, potash, and lime. 
As in these trials the object was merely to ascertain the 
general fact of decomposition, the process was never con- 
ducted for a sufficient time to develope a quantity of alkaline 
matter capable of being conveniently weighed, and of course 
any loss of w r eight of the substance could not be determined. 
