CHEMICAL SCIENCE. 219 



forms rhomboheclrie crystals of a copperish gray color, found in 

 calcite, and accompanied with acicular arsenical pyrites. Breit- 

 haupt has confounded alloclase with glaucodote. — Reader. 



NATIVE LEAD FROM LAKE SUPERIOR. 



On the American continent — apart from its occurrence in the 

 meteoric iron of Tarapaca, in Chili — native lead has hitherto been 

 noticed only at one spot, viz., in a galena vein, traversing lime- 

 stone (of unstated geological age), near Zomelahuacan, in the 

 province of Vera Cruz, in central Mexico. The specimen from 

 the locality now under consideration, was obtained at a sjjot near 

 the celebrated Dog Lake of the Kaministiquia. The lead occurs 

 in this specimen — the only one discovered — in the form of a 

 small string in white, semi-opaque quartz. The quartz, which 

 forms a narrow vein, does not appear to contain the slightest 

 speck of galena, or any other substance, except a small quantity 

 of specular iron ore ; and the unaltered appearance of the latter is 

 such as to preclude the suj^position of the lead having been de- 

 rived from galena, or other lead compound, by artificial heat. The 

 lead, when cut, presents the ordinary' color, softness, ductility, and 

 other ph3'sical and chemical properties of the pure metal. 



This discovery is interesting, not only from the extreme rarity 

 of native lead, but from the fact that, in the few undoubted Euro- 

 pean localities in which the metal has been found, the latter is 

 generally accompanied by gold. The quartz in which this speci- 

 men occurs, has, curiously enough, the somewhat waxy aspect and 

 other characters of the gold-bearing quartz of California and other 

 auriferous districts ; and the geological position of the bounding 

 rock, immediately above that of the Huronian strata, is in a meas- 

 ure identical with the horizon of the gold-bearing rocks from which 

 the auriferous deposits of Eastern Canada have been derived. No 

 gold has hitherto been met with, however, in the sands of the 

 Kaministiquia and other streams of Thunder Bay. — Canadian 

 Journal, November, 1863. 



BORAX IN CALirORINA. 



Clear Lake is about sixty-five miles northwest of Suisun Bay, 

 and about thirty-six miles from the Pacific Ocean. Borax Lake 

 occupies a depression on the east side of the narrow arm of Clear 

 Lake, from which it is sepai-ated by a low ridge of loose volcanic 

 materials, consisting of scorite, obsidian, and pumice. Boi'ax Lake 

 is of variable dimensions, according to the season of the year and 

 the comparative dryness of the season. In September, 1863, the 

 water occupied an area about 4,000 feet long and 1,800 feet wide 

 in the widest 2:)lace, irregularly oval, its longer axis turned in the 

 direction of east and west, magnetic ; the water was about three 

 feet deep ; it has been known to extend over twice this area, and 

 has also been at times entirely dry. The water from this lake, in 

 September, 1863, contained 2,401.66 grains of solid matter to the 

 gallon, of which about one-quarter was borate of soda, there being 



