424 Chronicles of Science. [July, 
prednged about 12,000,000 dollars, and silver about 5,000,000 
dollars. 
Gold.—7,202 mining establishments are reported. These are 
situated in California, New Mexico, Oregon, North Carolina, 
Georgia, Virginia, and South Carolina, placing the States in the 
order of their productiveness. The gold they produced is given as 
47,566,000 dollars. ) 
Those who are interested in the mode of occurrence of petro- 
leum may obtain a large amount of information by referring to the 
‘ Proceedings of the American Philosophical Society for May, 1865,’ 
in which will be found a very satisfactory description of the petro- 
leum deposits in the eastern coal-field of Kentucky, by Mr. T. P. 
Lesley. 
The general condition of an “Oil” country is thus described. 
Mr. Lesley is writing especially of the neighbourhood of Paint 
Lick Creek, Kentucky. ‘ Petroleum is the mineral that excites 
most interest at present in all this region, and the show which it 
makes upon the surface is extraordmary. It issues in numerous 
places from the base of the cliffs which form the walls of the 
cafions, through which flow the main Paint and its many branches. 
It saturates the slopes and banks of loose sand. It flows off, when 
the sand is stirred with a stick, as a shining scum upon the surface 
of the stream. It has been caught against booms and barrelled for 
sale. It unites, also, with the sweepings from the sub-conglomerate 
ore and coal shales, and forms slimy ore-bogs and muck-heaps, 
where the base of the conglomerate is at any greater height than 
usual above the water-bed, and the slope from it is therefore longer 
than usual. Such is the case at the Old Oil Springs, on the north 
line of the May and Ross Survey, where it crosses the Little 
or South Fork of Paint; and again 200 yards lower down, at 
Pendleton’s Oil Springs. 
“A black reservoir of tar-like oil here occupies the centre of 
a sloping bog, and is kept always full from a spring at its upper 
limit, near the top of the slope and the foot of the cliffs, about 
twenty feet above the level of the stream.” 
A remarkable extension of shale mining for the production of 
petroleum is also taking place in this country. More than 100 retorts 
have lately been set to work in North Staffordshire. In Derbyshire 
and in Yorkshire many works are rapidly progressing towards com- 
pletion, for the distillation of oil. All the old works in Flintshire 
are actively distilling cannel coal and shale; and in addition to the 
established works in Scotland, using the Torbanechill mineral, several 
others are starting. The consequent enormous production of “ coal 
ou” in this country, added to the immense importation of petroleum 
from America, must lead to a great reduction of price, and an 
extension of its use for illuminating and lubricating purposes. 
