416 Proceedings of the Royal Physical Society. 
as to the origin of quartz and gold is, that at one time the 
earth's surface was very much cracked, and that melted 
silica, containing metal in minute division, was projected up 
from the interior and filled these cracks, forming quartz reefs 
and veins ; that the metal got cooled in its ascent and 
formed gold; that most of it, from its volatility, rose to the 
surface and became deposited there ; but lately many things 
have occurred to shake this theory. One of them is, that 
the yield of gold does not decrease as they go downwards in 
working the reef. A Government commission went round 
the gold-fields last year making all inquiries on this very 
subject, but all mining men here dispute their verdict, 
which was to the effect, that the lower you went the purer 
the quartz became. I saw two mining managers at Clunes 
lately, who told me their experience went to the contrary, 
and I have asked many Ballarat men, who agree with the 
Olunes managers. Another circumstance which has given 
rise to a totally different theory is, that at Smythesdale a 
piece of petrified wood was discovered on which was a 
deposit of iron pyrites and gold. The favourite theory now 
is, that electricity is the agent which produces gold, and that 
it requires to pass through certain feeding grounds to be so 
produced ; but I have never seen a written statement of this 
theory, although, if there is one, I shall try and get it for 
you. 
" The general map of the Ballarat district will show you 
the way in which the leads all run, and is on this account, 
I think, very interesting. It includes the gold-fields also 
of Clunes, Creswick, Sago Hill, Smythe's, Brown's, Linton's, 
Carngham, Lucky Woman's, Italian's, Buninyong, and Hard • 
Hills. From Ballarat to Clunes the basaltic plain extends, 
which begins at the side of the Yarrowee. It goes far 
beyond Clunes on the north side, and how far south I do 
not know, and over all the way to Burrumbut, with occa- 
sional cropping out of hills and other formations, as for 
instance, quartz in the Creswick gold-field ; and as the 
farthest mines are not more than half a mile from the edge 
of this plateau, it seems to me that the basaltic plain covers 
