116 Chronicles of Science. | Jan., 
Cornish mineral, which appears to be a Hydrated Plumbo-cuprie 
Arsenate. “Although many mineral species are double compounds 
of copper and lead (Caledonite, Chileite, Linarite, Vauquelinite, &c.), 
yet I am not aware of any double arsenate of lead and copper, defi- 
nite and constant in composition, having been yet discovered and 
described.” (Church.) Bayldonite occurs in minute mammillary 
concretions having a dusty surface. The structure of the masses is 
often somewhat reticulated after the manner occasionally observed in 
certain Travertines. The fracture is slightly conchoidal, uneven, 
translucent on the edges; colour, grass-green to blackish green ; 
colour of the powder, siskin-green to apple-green ; hardness, about 
4:5; specific gravity, 5°35; analytical percentages as follows :— 
5S LR gail lI lb aan Hod Sib 9.09 
Cu"O . ° : ° . ° : 30 88 
ABS IO) des sensi. “te ae Niche Ace ee 
EOL eee Ota ee ee 458 
Ferric Oxide and loss ° . . . 2°65 
100-00 
Petroleum is being found in numerous new districts. In Cali- 
fornia it is discovered in the county of Santa Clara, not far from 
Gilroy, and a few miles from the route opened between San Juan 
and Monterey. The sources are on each side of a deep ravine, on the 
sides of a little river, a tributary to the Panjaro. It is stated that 
from 20 to 30 barrels of “oil” are obtained in twenty-four hours, 
but that a much larger quantity was readily obtainable. 
A company has been formed for exploring the sources of Petro- 
leum, which are said to be abundant in Zante, one of the Ionian 
Islands. ‘The occurrence of petroleum in Zante was known at least 
2,000 years since, for Herodotus correctly describes the bituminous 
springs. 
x An important paper “On the Ores of Manganese and their 
Uses,” appears in the ‘ Transactions of the Nova Scotian Institute of 
Natural Science.’ An abstract of this paper is given in the 
* Chemical News,’ November 17th. 
Mr. C. Greville Williams has demonstrated the existence of 
Didymium in“ Churchite,” as the oxide of Cerium discovered by 
Professor Church has been called. 
Bismuth is said to have been discovered in Spencer’s Gulf, 
South Australia, where a mine is now vigorously working and likely 
to prove profitable.* 
Mr. George Maw, of Broseley, communicates some interesting 
particulars relative to the occurrence of a very white sand, which 
is a “perfectly pure form of native silica,” occurring in Talargoch 
mine, near Prestatyn, in Flintshire. One of the lodes in this mine 
* ‘South Australian Register,’ September 27, 1865. 
