ACADEMY OP NATURAL SCIENCES. 297 



chiefly in the lower Sierra, and in the small valleys east of the red- 

 woods in Mendocino County. Q. agrifolia occurs almost exclu- 

 sively in the vicinity of San Francisco Bay, and on the banks of 

 streams emptying into it. It extends also southward, approaching 

 the coast more nearly as we reach Monterey. 



Regular Meeting, October 15th, 1866. 



Dr. Kellogg in the chair. 



Eleven members present. 



Mr. A. L. Bancroft was elected a Resident Member. 

 Donations to the Library : 



Bodemann and Kerl's Treatise on Assaying, translated by W. A. 

 Goodyear, presented by the translator. 



Prof. W. P. Blake read the following : 



Mineralogical Notices.— No. II. 



BY W5I. P. BLAKE. 



Kerargyrite. — Chloride of silver in remarkably fine specimens occurs in the 

 " Poorman lode," Idaho, associated with Prpustite (light red silver ore), native 

 silver and native gold. Sheets of the chloride are taken out of the soft clay of 

 the vein, and are from one-eighth to one-quarter of an inch in thickness. It is 

 also found in irregular massive aggregations of crystals, in cubes, without any 

 mpdification, and over an eighth of an inch square. The color of my specimens 

 is brown, passing into violet blue in some portions. 



Proustite. — The " ruby silver " which occurs with the chloride in the Poor- 

 man lode, as above, is often in masses of several ounces, or even pounds, in 

 weight, and it is reported to be occasionally seen in beautiful crystals, but none 

 have yet come under my observation. 



Copper Glance, Red Oxide of Copper, Native Copper. — These species are 

 found together in the " Ped Cap claim," Klamath County, California, in ser- 

 pentine. The metallic copper is seen in points throughout the massive sulphuret, 

 and is sometimes enveloped in red oxide. Both copper and oxide are most 

 abundant in the outer portions of the ore, as found, and they are apparently 

 formed by the gradual decomposition of the sulphuret. 



Danaite. — A cobaltic variety of mispickel is found associated with iron and 



PROO. CAL. ACAD. VOL. III. ^1 Jan. 1867. 



